WorldWideScience

Sample records for event-related oscillations eros

  1. Event-related oscillations versus event-related potentials in a P300 task as biomarkers for alcoholism.

    Science.gov (United States)

    Andrew, Colin; Fein, George

    2010-04-01

    It has been proposed that event-related oscillation (ERO) measures of EEG activity recorded in P300 tasks provide more powerful biomarkers of alcoholism than event-related potential (ERP) measures. This study examines this question in a group of long-term abstinent alcoholics (LTAAs). EEGs were recorded on 48 LTAAs and 48 age and gender-matched nonalcoholic controls (NACs) during the performance of a 3-condition visual target detection task. The event-related data were analyzed to extract ERP amplitude measures and total and evoked ERO power measures. Data were analyzed using multivariate analysis of covariance to determine the contributions of ERO versus ERP measures to discriminate between the LTAA versus NAC groups. The LTAA group showed significantly lower evoked delta ERO power and total delta and theta ERO power compared to the control group. The evoked and total ERO power measures provide an alternative (but not more powerful) representation of the group difference than does P3b amplitude. There was a weak suggestion that nonphase-locked theta ERO power (which contributes to total ERO power) might provide independent discriminatory information. Reduced evoked ERO power in the response to target stimuli provided an alternative and comparable representation of the reduced P3b amplitude in LTAA. This is not surprising as the evoked ERO power measures are derived from time-frequency representations of the ERP waveform. Induced theta oscillations might provide independent discriminatory information beyond ERP amplitude measures, but separate analysis of the event-related nonphase-locked activity is required to investigate this further.

  2. Event-related oscillations in the parietal cortex of adult alcohol-preferring (P) and alcohol-nonpreferring rats (NP).

    Science.gov (United States)

    Criado, José R; Ehlers, Cindy L

    2010-06-01

    The selectively bred alcohol-preferring (P) and -nonpreferring (NP) lines were developed from Wistar rats to model high and low voluntary alcohol consumption and have been demonstrated to exhibit many of the characteristics of human alcohol dependence. Electrophysiologic studies have shown P rats exhibit more electroencephalographic fast frequency activity and reduced P3 amplitude in the parietal cortex than NP rats, findings that are more common in alcohol-dependent individuals. Event-related oscillations (EROs) have been suggested to be good endophenotypes associated with ethanol dependence in clinical studies. Recently EROs have also been demonstrated to occur in rodents in response to stimuli that are similar to that used in human clinical studies. The objective of the present study was to characterize EROs in adult P and NP rats. A time-frequency representation method was used to determine delta, theta, and alpha/beta ERO energy and the degree of phase variation in the parietal cortex of adult P and NP rats. The present results suggest that the decrease in P3 amplitudes previously shown in P rats were not associated with changes in ERO energy but were significantly associated with decreases in evoked delta and alpha/beta phase locking. These studies demonstrate ERO measures may also be good endophenotypes in animal models of alcoholism. 2010 Elsevier Inc. All rights reserved.

  3. Final Report on LDRD project 130784 : functional brain imaging by tunable multi-spectral Event-Related Optical Signal (EROS).

    Energy Technology Data Exchange (ETDEWEB)

    Speed, Ann Elizabeth; Spahn, Olga Blum; Hsu, Alan Yuan-Chun

    2009-09-01

    Functional brain imaging is of great interest for understanding correlations between specific cognitive processes and underlying neural activity. This understanding can provide the foundation for developing enhanced human-machine interfaces, decision aides, and enhanced cognition at the physiological level. The functional near infrared spectroscopy (fNIRS) based event-related optical signal (EROS) technique can provide direct, high-fidelity measures of temporal and spatial characteristics of neural networks underlying cognitive behavior. However, current EROS systems are hampered by poor signal-to-noise-ratio (SNR) and depth of measure, limiting areas of the brain and associated cognitive processes that can be investigated. We propose to investigate a flexible, tunable, multi-spectral fNIRS EROS system which will provide up to 10x greater SNR as well as improved spatial and temporal resolution through significant improvements in electronics, optoelectronics and optics, as well as contribute to the physiological foundation of higher-order cognitive processes and provide the technical foundation for miniaturized portable neuroimaging systems.

  4. Event-related oscillations in offspring of alcoholics: neurocognitive disinhibition as a risk for alcoholism.

    Science.gov (United States)

    Kamarajan, Chella; Porjesz, Bernice; Jones, Kevin; Chorlian, David; Padmanabhapillai, Ajayan; Rangaswamy, Madhavi; Stimus, Arthur; Begleiter, Henri

    2006-04-01

    Event-related oscillations (EROs) are increasingly being used to assess neurocognitive functioning in normal and clinical populations. The current study compares different frequency activities in offspring of alcoholics (OA) and in normal control subjects (NC) to examine whether the OA group exhibits any abnormality in oscillatory activity while performing a Go/NoGo task. The S-transform algorithm was employed to decompose the electroencephalographic (EEG) signals into different time-frequency bands, and the oscillatory responses in the P300 time window (300-700 milliseconds) were statistically analyzed in both groups. The OA group manifested significantly decreased activity in delta (1-3 Hz), theta (4-7 Hz), and alpha1 (8-9 Hz) bands during the NoGo condition, as well as reduced delta and theta activity during the Go condition. This reduction was more prominent in the NoGo than in the Go condition. The decreased response in delta, theta, and alpha1 oscillations, especially during the NoGo condition in high-risk individuals, is perhaps suggestive of cognitive and neural disinhibition and may serve as an endophenotypic marker in the development of alcoholism and/or other disinhibitory disorders.

  5. Deficient Event-Related Theta Oscillations in Individuals at Risk for Alcoholism: A Study of Reward Processing and Impulsivity Features.

    Science.gov (United States)

    Kamarajan, Chella; Pandey, Ashwini K; Chorlian, David B; Manz, Niklas; Stimus, Arthur T; Anokhin, Andrey P; Bauer, Lance O; Kuperman, Samuel; Kramer, John; Bucholz, Kathleen K; Schuckit, Marc A; Hesselbrock, Victor M; Porjesz, Bernice

    2015-01-01

    Individuals at high risk to develop alcoholism often manifest neurocognitive deficits as well as increased impulsivity. Event-related oscillations (EROs) have been used to effectively measure brain (dys)function during cognitive tasks in individuals with alcoholism and related disorders and in those at risk to develop these disorders. The current study examines ERO theta power during reward processing as well as impulsivity in adolescent and young adult subjects at high risk for alcoholism. EROs were recorded during a monetary gambling task (MGT) in 12-25 years old participants (N = 1821; males = 48%) from high risk alcoholic families (HR, N = 1534) and comparison low risk community families (LR, N = 287) from the Collaborative Study on the Genetics of Alcoholism (COGA). Impulsivity scores and prevalence of externalizing diagnoses were also compared between LR and HR groups. HR offspring showed lower theta power and decreased current source density (CSD) activity than LR offspring during loss and gain conditions. Younger males had higher theta power than younger females in both groups, while the older HR females showed more theta power than older HR males. Younger subjects showed higher theta power than older subjects in each comparison. Differences in topography (i.e., frontalization) between groups were also observed. Further, HR subjects across gender had higher impulsivity scores and increased prevalence of externalizing disorders compared to LR subjects. As theta power during reward processing is found to be lower not only in alcoholics, but also in HR subjects, it is proposed that reduced reward-related theta power, in addition to impulsivity and externalizing features, may be related in a predisposition to develop alcoholism and related disorders.

  6. Deficient Event-Related Theta Oscillations in Individuals at Risk for Alcoholism: A Study of Reward Processing and Impulsivity Features.

    Directory of Open Access Journals (Sweden)

    Chella Kamarajan

    Full Text Available Individuals at high risk to develop alcoholism often manifest neurocognitive deficits as well as increased impulsivity. Event-related oscillations (EROs have been used to effectively measure brain (dysfunction during cognitive tasks in individuals with alcoholism and related disorders and in those at risk to develop these disorders. The current study examines ERO theta power during reward processing as well as impulsivity in adolescent and young adult subjects at high risk for alcoholism.EROs were recorded during a monetary gambling task (MGT in 12-25 years old participants (N = 1821; males = 48% from high risk alcoholic families (HR, N = 1534 and comparison low risk community families (LR, N = 287 from the Collaborative Study on the Genetics of Alcoholism (COGA. Impulsivity scores and prevalence of externalizing diagnoses were also compared between LR and HR groups.HR offspring showed lower theta power and decreased current source density (CSD activity than LR offspring during loss and gain conditions. Younger males had higher theta power than younger females in both groups, while the older HR females showed more theta power than older HR males. Younger subjects showed higher theta power than older subjects in each comparison. Differences in topography (i.e., frontalization between groups were also observed. Further, HR subjects across gender had higher impulsivity scores and increased prevalence of externalizing disorders compared to LR subjects.As theta power during reward processing is found to be lower not only in alcoholics, but also in HR subjects, it is proposed that reduced reward-related theta power, in addition to impulsivity and externalizing features, may be related in a predisposition to develop alcoholism and related disorders.

  7. Event-Related EEG Oscillations to Semantically Unrelated Words in Normal and Learning Disabled Children

    Science.gov (United States)

    Fernandez, Thalia; Harmony, Thalia; Mendoza, Omar; Lopez-Alanis, Paula; Marroquin, Jose Luis; Otero, Gloria; Ricardo-Garcell, Josefina

    2012-01-01

    Learning disabilities (LD) are one of the most frequent problems for elementary school-aged children. In this paper, event-related EEG oscillations to semantically related and unrelated pairs of words were studied in a group of 18 children with LD not otherwise specified (LD-NOS) and in 16 children with normal academic achievement. We propose that…

  8. Biological Computation Indexes of Brain Oscillations in Unattended Facial Expression Processing Based on Event-Related Synchronization/Desynchronization

    Directory of Open Access Journals (Sweden)

    Bo Yu

    2016-01-01

    Full Text Available Estimation of human emotions from Electroencephalogram (EEG signals plays a vital role in affective Brain Computer Interface (BCI. The present study investigated the different event-related synchronization (ERS and event-related desynchronization (ERD of typical brain oscillations in processing Facial Expressions under nonattentional condition. The results show that the lower-frequency bands are mainly used to update Facial Expressions and distinguish the deviant stimuli from the standard ones, whereas the higher-frequency bands are relevant to automatically processing different Facial Expressions. Accordingly, we set up the relations between each brain oscillation and processing unattended Facial Expressions by the measures of ERD and ERS. This research first reveals the contributions of each frequency band for comprehension of Facial Expressions in preattentive stage. It also evidences that participants have emotional experience under nonattentional condition. Therefore, the user’s emotional state under nonattentional condition can be recognized in real time by the ERD/ERS computation indexes of different frequency bands of brain oscillations, which can be used in affective BCI to provide the user with more natural and friendly ways.

  9. Delta, theta, and alpha event-related oscillations in alcoholics during Go/NoGo task: Neurocognitive deficits in execution, inhibition, and attention processing.

    Science.gov (United States)

    Pandey, Ashwini K; Kamarajan, Chella; Manz, Niklas; Chorlian, David B; Stimus, Arthur; Porjesz, Bernice

    2016-02-04

    Higher impulsivity observed in alcoholics is thought to be due to neurocognitive functional deficits involving impaired inhibition in several brain regions and/or neuronal circuits. Event-related oscillations (EROs) offer time-frequency measure of brain rhythms during perceptual and cognitive processing, which provide a detailed view of neuroelectric oscillatory responses to external/internal events. The present study examines evoked power (temporally locked to events) of oscillatory brain signals in alcoholics during an equal probability Go/NoGo task, assessing their functional relevance in execution and inhibition of a motor response. The current study hypothesized that increases in the power of slow frequency bands and their topographical distribution is associated with tasks that have increased cognitive demands, such as the execution and inhibition of a motor response. Therefore, it is hypothesized that alcoholics would show lower spectral power in their topographical densities compared to controls. The sample consisted of 20 right-handed abstinent alcoholic males and 20 age and gender-matched healthy controls. Evoked delta (1.0-3.5Hz; 200-600ms), theta (4.0-7.5Hz; 200-400ms), slow alpha (8.0-9.5Hz; 200-300ms), and fast alpha (10.0-12.5Hz; 100-200ms) ERO power were compared across group and task conditions. Compared to controls, alcoholics had higher impulsiveness scores on the Barrett Impulsiveness Scale (BIS-11) and made more errors on Go trials. Alcoholics showed significantly lower evoked delta, theta, and slow alpha power compared to controls for both Go and NoGo task conditions, and lower evoked fast alpha power compared to controls for only the NoGo condition. The results confirm previous findings and are suggestive of neurocognitive deficits while executing and suppressing a motor response. Based on findings in the alpha frequency ranges, it is further suggested that the inhibitory processing impairments in alcoholics may arise from inadequate early

  10. Effects of memantine on event-related potential, oscillations, and complexity in individuals with and without family histories of alcoholism.

    Science.gov (United States)

    Narayanan, Balaji; Stevens, Michael C; Jiantonio, Rachel E; Krystal, John H; Pearlson, Godfrey D

    2013-03-01

    Enhanced N-methyl-D-aspartate (NMDA) receptor function associated with a positive family history of alcoholism (FHP) has been hypothesized to contribute to the heritable risk for alcoholism. The objective of this study was to evaluate the relationship of alcoholism family history, NMDA receptor function, and cortical information processing by testing acute effects of the NMDA receptor antagonist memantine on event-related potential (ERP). Twenty-two healthy FHP and 20 healthy family history-negative (FHN; no alcoholic relatives) subjects were administered placebo or 40 mg of memantine under double-blind counterbalanced conditions on two separate occasions. Electroencephalogram data were collected from eight channels with eyes open during an auditory oddball discrimination task. We evaluated P3b amplitude, total theta, alpha activity, and fractal dimension from ERP trials. FHP and FHN subjects did not differ in P3b amplitude. A significant Group × Drug interaction was observed in theta, alpha activity, and fractal dimension at the parietal and occipital sites. FHP individuals exhibited significantly higher fractal dimension and lower theta and alpha activity after placebo relative to FHN subjects. Following memantine administration, theta activity decreased in both groups but more markedly for FHN individuals. Alpha activity decreased for FHN subjects and increased for FHP individuals, whereas the fractal dimension decreased for FHP subjects and increased for FHN subjects after memantine. A plausible interpretation of these results is that FHP individuals may have altered NMDA receptor function compared with FHN individuals. These findings provide additional evidence of differences in the regulation of NMDA receptor function between FHP and FHN individuals.

  11. Temporal dynamics of attention during encoding vs. maintenance of working memory: complementary views from event-related potentials and alpha-band oscillations

    Science.gov (United States)

    Myers, Nicholas E.; Walther, Lena; Wallis, George; Stokes, Mark G.; Nobre, Anna C.

    2015-01-01

    Working memory (WM) is strongly influenced by attention. In visual working-memory tasks, recall performance can be improved by an attention-guiding cue presented before encoding (precue) or during maintenance (retrocue). Although precues and retrocues recruit a similar fronto-parietal control network, the two are likely to exhibit some processing differences, since precues invite anticipation of upcoming information, while retrocues may guide prioritisation, protection, and selection of information already in mind. Here we explored the behavioral and electrophysiological differences between precueing and retrocueing in a new visual working-memory task designed to permit a direct comparison between cueing conditions. We found marked differences in event-related potential (ERP) profiles between the precue and retrocue conditions. In line with precues primarily generating an anticipatory shift of attention toward the location of an upcoming item, we found a robust lateralization in late cue-evoked potentials associated with target anticipation. Retrocues elicited a different pattern of ERPs that was compatible with an early selection mechanism, but not with stimulus anticipation. In contrast to the distinct ERP patterns, alpha band (8-14 Hz) lateralization was indistinguishable between cue types (reflecting, in both conditions, the location of the cued item). We speculate that whereas alpha-band lateralization after a precue is likely to enable anticipatory attention, lateralization after a retrocue may instead enable the controlled spatiotopic access to recently encoded visual information. PMID:25244118

  12. Eros / Aare Ermel

    Index Scriptorium Estoniae

    Ermel, Aare, 1957-2013

    2006-01-01

    Kolmest iseseisvast armastusloost koosnev episoodfilm "Eros" : režissöörid Wong Kar-Wai ("Käsi"), Steven Soderbergh ("Tasakaal" / "Equilibrium"), Michelangelo Antonioni ("Asjade ohtlik käik") : Hongkong - Hiina - USA - Prantsuse - Itaalia 2004

  13. Professor@s e Eros Teachers and Eros

    Directory of Open Access Journals (Sweden)

    Deborah P. Britzman

    2009-01-01

    Full Text Available Professores/as são testemunhas do fantástico mundo da sexualidade. Esse artigo explora a centralidade de Eros para a educação e estabelece uma relação entre o desejo do/a professor/a e os acontecimentos emocionais da relação própria relação aluno/professor. Eu proponho que o aprendizado deva envolver nosso "eu" erótico, além das nossas fantasias. Mas esta perspectiva requer que professores/as considerem uma psicologia do amor como um caminho principal para a as situações emocionais de Eros. Na sua conclusão este trabalho sugere uma pedagogia que dê as boas vindas tanto à homossexualidade como a heterossexualidade como expressões humanas do amor.Teachers bear witness to the wondrous world of sexuality. This essay explores the centrality of Eros to education and links the teacher's desire to the emotional situation of the student/teacher relationship. I propose that learning involves our erotic selves and our fantasy life. But such a view requires that teachers consider a psychology of love as lending insight into the emotional situation of Eros. The paper concludes by suggesting a pedagogy that welcomes homosexuality and heterosexuality as human expressions of love.

  14. Eros ja keel / Katre Kasemets

    Index Scriptorium Estoniae

    Kasemets, Katre

    2002-01-01

    Kirjandusteaduslik seminar "Eros ja keel: tõlgitavuse ja mõistmise retoorilised mustrid", toimus Käsmus Underi ja Tuglase Kirjanduskeskuse ning Ungari Teaduste Akadeemia Kirjandusinstituudi ühise koostööprojekti raames. Analüüside-arutluste lähtetekstiks oli Friedebert Tuglase novell "Maailma lõpus"

  15. NEAR GRS SPECTRA FOR EROS ORBIT PHASE

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains Gamma Ray Spectrometer (GRS) observations made during the Eros orbit phase of the NEAR mission. The individual observations are combined into...

  16. NEAR GRS SPECTRA FOR EROS SURFACE PHASE

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains Gamma Ray Spectrometer (GRS) observations made during the Eros surface phase of the NEAR mission. Only the GRF sensor made observations from...

  17. P 300 EVENT RELATED POTENTIAL IN DEPRESSION

    OpenAIRE

    Singh, R; Shukla, R.; Dalal, P. K.; Sinha, P.K.; Trivedi, J.K.

    2000-01-01

    P300 component of the event related potential (ERP) provides one neurophysiological index of cognitive dysfunction in depression. Forty subjects fulfilling DSM-III criteria for depression were compared to 40 age and sex matched normal controls. The P300 was recorded using the auditory odd-ball paradigm. Depressives had a significantly prolonged P300 latency and reduced P300 amplitude as compared to the controls. The P300 latency showed a significant positive correlation with age of the patien...

  18. Neural Dynamics Underlying Event-Related Potentials

    Science.gov (United States)

    Shah, Ankoor S.; Bressler, Steven L.; Knuth, Kevin H.; Ding, Ming-Zhou; Mehta, Ashesh D.; Ulbert, Istvan; Schroeder, Charles E.

    2003-01-01

    There are two opposing hypotheses about the brain mechanisms underlying sensory event-related potentials (ERPs). One holds that sensory ERPs are generated by phase resetting of ongoing electroencephalographic (EEG) activity, and the other that they result from signal averaging of stimulus-evoked neural responses. We tested several contrasting predictions of these hypotheses by direct intracortical analysis of neural activity in monkeys. Our findings clearly demonstrate evoked response contributions to the sensory ERP in the monkey, and they suggest the likelihood that a mixed (Evoked/Phase Resetting) model may account for the generation of scalp ERPs in humans.

  19. NEAR EROS RADIO SCIENCE DATA SET - EROS/ORBIT V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — The NEAR Eros Radio Science Data Set is a time-ordered collection of raw and partially processed data collected during the NEAR orbital mapping of the asteroid 433...

  20. NEAR MAG DATA FOR EROS/ORBIT

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains the NEAR magnetometer (MAG) data for the EROS/ORBIT phase. The data set begins on 2000-01-11T00:00:00.000 and ends 2001-02-12T23:59:59.999 ....

  1. Socrates, Plato, "Eros" and Liberal Education

    Science.gov (United States)

    McPherran, Mark L.

    2010-01-01

    This paper focuses on the educational method--the "elenchos"--of Plato's Socrates, arguing, against some prominent interpretations, that it is love, both "eros" and "philia", that is the key that links Socrates' philosophy with his education. This analysis, of course, raises some difficult questions regarding the relationship between teacher and…

  2. Event related potentials recorded in Dorsal Simultanagnosia.

    Science.gov (United States)

    Onofrj, M; Fulgente, T; Thomas, A

    1995-12-01

    Visual evoked potentials (VEPs) to central and lateral half field patterned stimuli of 1, 2 and 4 cycles per degree (cpd) were recorded in a patient with Dorsal Simultanagnosia due to bilateral lesions of parieto-occipital junction. VEPs consisted of the normal N1-P1-N2 components with same spatial frequency sensitivity as in controls. VEPs had similar latencies and amplitudes whether the patient could see or not the patterned stimuli. Event related potentials (ERPs) to visual and acoustic odd-ball paradigm were also recorded in the same patient. Visual ERPs consisted of an early NA-effect, and of N2-P3 components. P3 was recorded only from frontal, central and temporal derivations. The topographical P3 abnormality was, however, the same for visual and acoustic odd-ball paradigms. The amplitude of P3 was smaller when the patient missed visual stimuli. These findings show that severe bilateral lesions at the parieto-occipital junction, inducing Simultanagnosia, do not obliterate VEPs or ERPs components.

  3. A face pedagógica de Eros The pedagogical face of Eros

    Directory of Open Access Journals (Sweden)

    Marlene de Souza Dozol

    2007-08-01

    Full Text Available O presente trabalho busca descobrir a face pedagógica de Eros. Como ponto de partida, está o fato de a figura do educador/professor ser comumente representado por alguém cuja ocupação não suscita desejos de qualquer espécie. Não raras vezes assistimos a representações literárias e imagens televisivas ou cinematográficas nas quais o professor aparece comicamente como uma caricatura que fala, de modo monótono e sem parar, a alunos cujos rostos oscilam entre o tédio e o escárnio. No entanto, o que é de fato assustador é que, cada vez mais, as imagens que aparecem no discurso das novas gerações, numa tentativa de oposição à caricatura supracitada, associam a figura do professor à de um animador de auditório, performático, divertido, especialista em dinâmicas grupais catárticas, sem conteúdo e igualmente caricatural. Procurando, então, desviar-se de ambas as caricaturas e refletir sobre o gênero específico de libido pedagógica - compreendido como força ou energia espiritual para o progresso moral, intelectual e sensível -, o texto recupera o poder ilustrativo do mito, pensa sobre a força do imaginário na constituição de parâmetros modelares para a Educação e para o exercício da mestria (para isso, propõe notas socráticas, sofísticas e escolásticas com ênfase na linguagem e aponta para a importância dessa discussão diante dos problemas que habitam os espaços educativos contemporâneos.The present work seeks to uncover the pedagogical face of Eros. As a starting point, there is the fact that the figure of the educator/teacher is commonly represented by someone whose occupation does not elicit desires of any kind. It is not unusual to see literary representations and televised or cinema images in which the teacher appears comically as a caricature that talks continuously and monotonically to pupils whose countenances oscillate between boredom and scorn. But what is truly frightening is that, more and

  4. Cratering on Small Bodies: Lessons from Eros

    Science.gov (United States)

    Chapman, C. R.

    2003-01-01

    Cratering and regolith processes on small bodies happen continuously as interplanetary debris rains down on asteroids, comets, and planetary satellites. Butthey are very poorly observed and not well understood. On the one hand, we have laboratory experimentation at small scales and we have examination of large impact craters (e.g. Meteor Crater on Earth and imaging of abundant craters on terrestrial planets and outer planet moons). Understanding cratering on bodies of intermediate scales, tens of meters to hundreds of km in size, involves either extrapolation from our understanding of cratering phenomena at very different scales or reliance on very preliminary, incomplete examination of the observational data we now have for a few small bodies. I review the latter information here. It has been generally understood that the role of gravity is greatly diminished for smaller bodies, so a lot of cratering phenomena studied for larger bodies is less applicable. But it would be a mistake to imagine that laboratory experiments on gravitationless rocks (usually at 1 g) are directly applicable, except perhaps to those monolithic Near Earth Asteroids (NEAs) some tens of meters in size that spin very rapidly and can be assumed to be "large bare rocks" with "negative gravity". Whereas it had once been assumed that asteroids smaller than some tens of km diameter would retain little regolith, it is increasingly apparent that regolith and megoregolith processes extend down to bodies only hundreds of meters in size, perhaps smaller. Yet these processes are very different from those that pertain to the Moon, which is our chief prototype of regolith processes. The NEAR Shoemaker spacecraft's studies of Eros provide the best evidence to date about small-body cratering processes, as well as a warning that our theoretical understanding requires anchoring by direct observations. Eros: "Ponds", Paucity of Small Craters, and Other Mysteries. Although Eros is currently largely detached

  5. Social exclusion modulates event-related frontal theta and tracks ostracism distress in children.

    Science.gov (United States)

    van Noordt, Stefon J R; White, Lars O; Wu, Jia; Mayes, Linda C; Crowley, Michael J

    2015-09-01

    Social exclusion is a potent elicitor of distress. Previous studies have shown that medial frontal theta oscillations are modulated by the experience of social exclusion. Using the Cyberball paradigm, we examined event-related dynamics of theta power in the EEG at medial frontal sites while children aged 8-12 years were exposed to conditions of fair play and social exclusion. Using an event-related design, we found that medial frontal theta oscillations (4-8Hz) increase during both early (i.e., 200-400ms) and late (i.e., 400-800ms) processing of rejection events during social exclusion relative to perceptually identical "not my turn" events during inclusion. Importantly, we show that only for the later time window (400-800ms) slow-wave theta power tracks self-reported ostracism distress. Specifically, greater theta power at medial frontal sites to "rejection" events predicted higher levels of ostracism distress. Alpha and beta oscillations for rejection events were unrelated to ostracism distress at either 200-400ms or 400-800ms time windows. Our findings extend previous studies by showing that medial frontal theta oscillations for rejection events are a neural signature of social exclusion, linked to experienced distress in middle childhood. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Eros as godsdiens (of die religieuse viering van seks)

    African Journals Online (AJOL)

    p1243322

    Abstract. Eros as religion (or the religious celebration of sex). This article unashamedly argues for the positive value of sexuality and its profound religious dimensions. A stance is taken that goes beyond moralizing and ethicizing. The relationship in the Bible between eros and religion is explored by referring to the sexual.

  7. Eros as godsdiens (of die religieuse viering van seks) | Scheffler ...

    African Journals Online (AJOL)

    Eros as religion (or the religious celebration of sex) This article unashamedly argues for the positive value of sexuality and its profound religious dimensions. A stance is taken that goes beyond moralizing and ethicizing. The relationship in the Bible between eros and religion is explored by referring to the sexual image of ...

  8. Aion, Eros e Hades nei frammenti caldaici

    Directory of Open Access Journals (Sweden)

    Silvia Lenzi

    2006-01-01

    Full Text Available The essay deals with some aspects of the knotty question concerning the presence of Aion, Eros and Hades in the variegated universe of the Chaldean Oracles, traditionally attributed to a collaboration between two “Hellenized Magi” of the second c. AD: Julian “the Chaldean” and his son Julian “the Theurgist” (even if the theurgical expertise of the elder Julian, the repository of a more ancient Chaldean tradition, might not involve a direct eastern origin but only his knowledge of “Chaldean” sciences such as astrology and divination”. Aion, who is examined here in terms of his relationship with Chronos, as a more or less autonomous divinity, is mentioned only in the context of some fragments, but his name never appears in the oracular verses. Eros (beloging also to the triad of fr. 46, along with “Faith” and “Truth” stands for an independent cosmological principle whose task is to preserve the universe and the armony of the cosmos. The Chaldean Oracles never make any explicit mention of Hades, who anyway is cited by the Byzantine scholar Psellos as an autonomous divinity of the Chaldeans.

  9. Further Analyses of the 433Eros Global Lineament Map

    Science.gov (United States)

    Buczkowski, D. L.; Barnouin-Jha, O. S.; Wyrick, D.; Prockter, L. M.

    2009-03-01

    While some linear features identified on Eros are clearly formed by impact, others do not obviously follow any model predictions of lineation formation by impact and possibly represent a pre-existing internal structure. New analyses are presented.

  10. In liminal tension towards giving birth: Eros, the educator

    OpenAIRE

    Szakolczai, Árpád

    2013-01-01

    The discussion on the nature of Eros (love as sexual desire) in Plato’s Symposium offers us special insights concerning the potential role played by love in social and political life. While about Eros, the dialogue also claims to offer a true image of Socrates, generating a complex puzzle. This article offers a solution to this puzzle by reconstructing and interpreting Plato’s theatrical presentation his argument, making use of the structure of the plays of Aristophanes, a prot...

  11. Intracerebral Event-related Potentials to Subthreshold Target Stimuli

    Czech Academy of Sciences Publication Activity Database

    Brázdil, M.; Rektor, I.; Daniel, P.; Dufek, M.; Jurák, Pavel

    2001-01-01

    Roč. 112, č. 4 (2001), s. 650-661 ISSN 1388-2457 R&D Projects: GA ČR GA309/98/0490 Institutional research plan: CEZ:AV0Z2065902 Keywords : event-related potentials * intracerebral recordings * oddball paradigm Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 1.922, year: 2001

  12. Review of evoked and event-related delta responses in the human brain.

    Science.gov (United States)

    Güntekin, Bahar; Başar, Erol

    2016-05-01

    In the last decade, the brain's oscillatory responses have invaded the literature. The studies on delta (0.5-3.5Hz) oscillatory responses in humans upon application of cognitive paradigms showed that delta oscillations are related to cognitive processes, mainly in decision making and attentional processes. The present manuscript comprehensively reviews the studies on delta oscillatory responses upon cognitive stimulation in healthy subjects and in different pathologies, namely Alzheimer's disease, Mild Cognitive Impairment (MCI), bipolar disorder, schizophrenia and alcoholism. Further delta oscillatory response upon presentation of faces, facial expressions, and affective pictures are reviewed. The relationship between pre-stimulus delta activity and post-stimulus evoked and event-related responses and/or oscillations is discussed. Cross-frequency couplings of delta oscillations with higher frequency windows are also included in the review. The conclusion of this review includes several important remarks, including that delta oscillatory responses are involved in cognitive and emotional processes. A decrease of delta oscillatory responses could be a general electrophysiological marker for cognitive dysfunction (Alzheimer's disease, MCI, bipolar disorder, schizophrenia and alcoholism). The pre-stimulus activity (phase or amplitude changes in delta activity) has an effect on post-stimulus EEG responses. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Measurement of event-related potentials and placebo

    Directory of Open Access Journals (Sweden)

    Sovilj Platon

    2014-01-01

    Full Text Available ERP is common abbreviation for event-related brain potentials, which are measured and used in clinical practice as well as in research practice. Contemporary studies of placebo effect are often based on functional neuromagnetic resonance (fMRI, positron emission tomography (PET, and event related potentials (ERP. This paper considers an ERP instrumentation system used in experimental researches of placebo effect. This instrumentation system can be divided into four modules: electrodes and cables, conditioning module, digital measurement module, and PC module for stimulations, presentations, acquisition and data processing. The experimental oddball paradigm is supported by the software of the instrumentation. [Projekat Ministarstva nauke Republike Srbije, br. TR32019 and Provincial Secretariat for Science and Technological Development of Autonomous Province of Vojvodina (Republic of Serbia under research grant No. 114-451-2723

  14. [EVENT-RELATED POTENTIALS AND CLINICAL SYMPTOMS IN SCHIZOPHRENIA].

    Science.gov (United States)

    Domján, Nóra; Csifcsák, Gábor; Janka, Zoltán

    2016-01-30

    The investigation of schizophrenia's aetiology and pathomechanism is of high importance in neurosciences. In the recent decades, analyzing event-related potentials have proven to be useful to reveal the neuropsychological dysfunctions in schizophrenia. Even the very early stages of auditory stimulus processing are impaired in this disorder; this might contribute to the experience of auditory hallucinations. The present review summarizes the recent literature on the relationship between auditory hallucinations and event-related potentials. Due to the dysfunction of early auditory sensory processing, patients with schizophrenia are not able to locate the source of stimuli and to allocate their attention appropriately. These deficits might lead to auditory hallucinations and problems with daily functioning. Studies involving high risk groups may provide tools for screening and early interventions; thus improving the prognosis of schizophrenia.

  15. Somatosensory Event-related Potentials from Orofacial Skin Stretch Stimulation

    OpenAIRE

    Ito, Takayuki; Ostry, David J; Gracco, Vincent

    2015-01-01

    International audience; Cortical processing associated with orofacial somatosensory function in speech has received limited experimental attention due to the difficulty of providing precise and controlled stimulation. This article introduces a technique for recording somatosensory event-related potentials (ERP) that uses a novel mechanical stimulation method involving skin deformation using a robotic device. Controlled deformation of the facial skin is used to modulate kinesthetic inputs thro...

  16. Eros as godsdiens (of die religieuse viering van seks

    Directory of Open Access Journals (Sweden)

    Eben Scheffler

    2008-01-01

    Full Text Available Eros as religion (or the religious celebration of sex This article unashamedly argues for the positive value of sexuality and its profound religious dimensions. A stance is taken that goes beyond moralizing and ethicizing. The relationship in the Bible between eros and religion is explored by referring to the sexual image of God in Genesis 1:26-27, the religious dimension of the book of Song of Songs and Jesus’ stance in contrast with that of Paul. Through religion humans’ sexual experience should be enhanced in stead of being suppressed. Society should be sexualized.

  17. A novel disulphide switch mechanism in Ero1 balances ER oxidation in human cells

    DEFF Research Database (Denmark)

    Appenzeller-Herzog, Christian; Riemer, Jan; Christensen, Brian

    2008-01-01

    Oxidative maturation of secretory and membrane proteins in the endoplasmic reticulum (ER) is powered by Ero1 oxidases. To prevent cellular hyperoxidation, Ero1 activity can be regulated by intramolecular disulphide switches. Here, we determine the redox-driven shutdown mechanism of Ero1 , the hou...

  18. Human Auditory Processing: Insights from Cortical Event-related Potentials

    Directory of Open Access Journals (Sweden)

    Alexandra P. Key

    2016-04-01

    Full Text Available Human communication and language skills rely heavily on the ability to detect and process auditory inputs. This paper reviews possible applications of the event-related potential (ERP technique to the study of cortical mechanisms supporting human auditory processing, including speech stimuli. Following a brief introduction to the ERP methodology, the remaining sections focus on demonstrating how ERPs can be used in humans to address research questions related to cortical organization, maturation and plasticity, as well as the effects of sensory deprivation, and multisensory interactions. The review is intended to serve as a primer for researchers interested in using ERPs for the study of the human auditory system.

  19. Sample Selected Averaging Method for Analyzing the Event Related Potential

    Science.gov (United States)

    Taguchi, Akira; Ono, Youhei; Kimura, Tomoaki

    The event related potential (ERP) is often measured through the oddball task. On the oddball task, subjects are given “rare stimulus” and “frequent stimulus”. Measured ERPs were analyzed by the averaging technique. In the results, amplitude of the ERP P300 becomes large when the “rare stimulus” is given. However, measured ERPs are included samples without an original feature of ERP. Thus, it is necessary to reject unsuitable measured ERPs when using the averaging technique. In this paper, we propose the rejection method for unsuitable measured ERPs for the averaging technique. Moreover, we combine the proposed method and Woody's adaptive filter method.

  20. NEAR MAG DATA FOR EROS/FLY/BY

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains the NEAR magnetometer (MAG) data for the EROS/FLY/BY phase. The data set begins on 1998-12-23T00:00:00.000 and ends 1998-12-23T23:59:59.999 ....

  1. Hydrokinetic energy resource estimates of River ERO at Lafiagi ...

    African Journals Online (AJOL)

    effective renewable energy solution without requiring the construction of a dam or of large civil works. Field studies were performed at a selected site along the Ero River, one of the tributaries of River Niger, North-central Nigeria to assess the ...

  2. Giorgio Perlasca, 'Giusto tra le nazioni' e 'eroe italiano'

    NARCIS (Netherlands)

    Jansen, M.M.

    2008-01-01

    Giorgio Perlasca che, fingendosi console spagnolo, nel 1944 salvò più di cinquemila ebrei ungheresi a Budapest, è stato proclamato “Giusto tra le Nazioni” a Yad Vashem nel 1989, dopo di che è seguito il suo riconoscimento all’estero ed in Italia come “uomo giusto” e come “eroe italiano”. Dopo il

  3. Formation of the "ponds" on asteroid (433) Eros by fluidization

    Science.gov (United States)

    Sears, D. W. G.; Tornabene, L. L.; Osinski, G. R.; Hughes, S. S.; Heldmann, J. L.

    2015-11-01

    The "ponds" on asteroid (433) Eros are fine-grained deposits approximating flat (quasi-equipotential) surfaces with respect to local topographic depressions (e.g., craters) in spacecraft images. These ponds are discussed in the context of laboratory simulation experiments, crater-related ponded and pitted deposits observed on Mars and Vesta, terrestrial phreatic craters, and degassing features associated with eroded impact craters on Earth. While the details of formation of these features on Mars, Vesta and the Earth are thought to be different, they all include mechanisms that require the interactions between surface materials and volatiles (e.g., water vapor). Indeed, analogous features similar to the Eros ponds can be reproduced in the laboratory by the release of vapor (ice sublimation, water evaporation, or N2) through an unconsolidated regolith (independent of regolith composition). Eros is widely thought to be dry, but the discovery of exogenic water on Vesta, and recent arguments that subsurface water might be present in the inner asteroid belt suggest that endogenic water might also be present and serve as a source of the gases produced in the ponds. The amount of water required is comparable to the amount of water observed in little-metamorphosed ordinary chondrites (a few wt%). The primary morphologic characteristics of the Eros ponds can be explained in this model. The heat source for degassing could have been solar heating following transfer from a main belt orbit to a near Earth orbit. Although other hypotheses (e.g., electrostatic levitation, seismic shaking, and comminution of boulders) can account for most of the features of the ponds, recent observations regarding the role of volatiles on planetary surfaces, our laboratory experiments, and fluidization deposits on active comets suggests that degassing is a reasonable hypothesis to be considered and further tested for explaining the Eros ponds, and similar features on other bodies.

  4. Conceptual integration and metaphor: an event-related potential study.

    Science.gov (United States)

    Coulson, Seana; Van Petten, Cyma

    2002-09-01

    Event-related brain potentials (ERPs) were recorded from 18 normal adults as they read sentences that ended with words used literally, metaphorically, or in an intermediate literal mapping condition. In the latter condition, the literal sense of the word was used in a way that prompted readers to map conceptual structure from a different domain. ERPs measured from 300 to 500 msec after the onset of the sentence-final words differed as a function of metaphoricity: Literal endings elicited the smallest N400, metaphors the largest N400, whereas literal mappings elicited an N400 of intermediate amplitude. Metaphoric endings also elicited a larger posterior positivity than did either literal or literal mapping words. Consistent with conceptual blending theory, the results suggest that the demands of conceptual integration affect the difficulty of both literal and metaphorical language.

  5. Adverse events related to the use of enteral nutritional therapy

    Directory of Open Access Journals (Sweden)

    Anamarta Sbeghen Cervo

    Full Text Available Aimed at verifying the occurrence of adverse events related to enteral nutrition use in patients of a public hospital in the countryside of Rio Grande do Sul. A quantitative, longitudinal and descriptive study, conducted in January-May 2012, that accompanied 46 patients admitted to the Intensive Care Unit and Medical Clinic. For evaluating the adverse events, we used quality indicators: inadvertent exit, tube obstruction and volume of infused diet. For analysis, we used descriptive statistics. The results showed that inadvertent exit of the tube and obstruction presented incidence rates of 4.6% and 2.1%, respectively. The volume of diet infused was less than that prescribed, due to pauses for body hygiene, tests and procedures, nausea / vomiting and delay in the availability of installation of the bottle in the unit. We conclude that the use of quality indicators in the assessment of care can help reduce damage to the patient.

  6. Event-Related Potentials and Emotion Processing in Child Psychopathology

    Directory of Open Access Journals (Sweden)

    Georgia eChronaki

    2016-04-01

    Full Text Available In recent years there has been increasing interest in the neural mechanisms underlying altered emotional processes in children and adolescents with psychopathology. This review provides a brief overview of the most up-to-date findings in the field of Event-Related Potentials (ERPs to facial and vocal emotional expressions in the most common child psychopathological conditions. In regards to externalising behaviour (i.e. ADHD, CD, ERP studies show enhanced early components to anger, reflecting enhanced sensory processing, followed by reductions in later components to anger, reflecting reduced cognitive-evaluative processing. In regards to internalising behaviour, research supports models of increased processing of threat stimuli especially at later more elaborate and effortful stages. Finally, in autism spectrum disorders abnormalities have been observed at early visual-perceptual stages of processing. An affective neuroscience framework for understanding child psychopathology can be valuable in elucidating underlying mechanisms and inform preventive intervention.

  7. Somatosensory Event-related Potentials from Orofacial Skin Stretch Stimulation.

    Science.gov (United States)

    Ito, Takayuki; Ostry, David J; Gracco, Vincent L

    2015-12-18

    Cortical processing associated with orofacial somatosensory function in speech has received limited experimental attention due to the difficulty of providing precise and controlled stimulation. This article introduces a technique for recording somatosensory event-related potentials (ERP) that uses a novel mechanical stimulation method involving skin deformation using a robotic device. Controlled deformation of the facial skin is used to modulate kinesthetic inputs through excitation of cutaneous mechanoreceptors. By combining somatosensory stimulation with electroencephalographic recording, somatosensory evoked responses can be successfully measured at the level of the cortex. Somatosensory stimulation can be combined with the stimulation of other sensory modalities to assess multisensory interactions. For speech, orofacial stimulation is combined with speech sound stimulation to assess the contribution of multi-sensory processing including the effects of timing differences. The ability to precisely control orofacial somatosensory stimulation during speech perception and speech production with ERP recording is an important tool that provides new insight into the neural organization and neural representations for speech.

  8. Possibility of reinforcement learning based on event-related potential.

    Science.gov (United States)

    Yamagishi, Yuya; Tsubone, Tadashi; Wada, Yasuhiro

    2008-01-01

    We applied event-related potential (ERP) to reinforcement signals that are equivalent to reward and punishment signals.We conducted an electroencephalogram (EEG) in which volunteers identified the success or failure of a task. We confirmed that there were differences in the EEG depending on whether the task was successful or not and suggested that ERP might be used as a reward of reinforcement leaning. We used a support vector machine (SVM) for recognizing the P300. We selected the feature vector in SVM that was composed of averages of each 50 ms for each of the six channels (C3,Cz,C4,P3,Pz,P4) for a total of 700 ms. We can suggest that reinforcement learning using P300 can be performed accurately.

  9. Developmental trajectories of event related potentials related to working memory.

    Science.gov (United States)

    Barriga-Paulino, Catarina I; Rodríguez-Martínez, Elena I; Arjona, Antonio; Morales, Manuel; Gómez, Carlos M

    2017-01-27

    Working memory is an important cognitive function, and it is crucial to better understand its neurophysiological mechanisms. The developmental trajectories of the Event Related Potentials related to this important function have hardly been studied. However, these ERPs may provide some clues about the individual state of maturation, as has been demonstrated for anatomical brain images. The present study aims to determine the behavioral and neurophysiological development of Working Memory (WM) processes. For this purpose, 170 subjects with ages ranging from 6 to 26 years performed a visual Delayed Match-to-Sample task (DMTS). The RTs, total errors, and Event Related Potentials (ERPs) in the phases of encoding, retention, and matching were obtained. Results revealed a decrease in the amplitude of ERPs with age, paralleled by improved performance on the DMTS task (i.e., shorter RTs and fewer errors). None of these variables were affected by gender. To determine whether memory performance was influenced by the individual pattern of maturation beyond age, the amplitude of the different ERP components was correlated with RT and errors on the WM task after removing the effect of age. Frontal N2 and posterior P1 and the Late Positive Component were the only ERPs that presented significant correlations with behavioral errors. Behavioral performance was predicted by age and by the scores on the first component extracted from Principal Component Analysis (PCA) of the ERPs. Age (under 17 years old) explained 85.04% and the PCA component explained 14.96% of the variance explained by the bivariate model predicting behavioral errors (1/age + scores of 1st PCA component). From the age of 17 on, the principal PCA component ceases to be an independent component predicting error performance. The results suggest that the individual maturation of ERP components seems to be of particular importance in controlling behavioral errors in WM, as measured by the DMTS. Copyright © 2016

  10. Many-valued logic and event-related potentials.

    Science.gov (United States)

    Pollina, D A; Squires, N K

    1998-07-01

    In previous experiments on event-related potentials (ERPs) during linguistic judgments, the subjects' decisions have been categorical (e.g., true vs false). In this experiment, more realistic variations in truth value and subject certainty were used. Thirty-eight naive undergraduates read a story about a fictional murder. ERPs were recorded as the subjects rated the strength of their beliefs about statements relating to suspects in the crime. Because no subject was sure which of the suspects was guilty of committing the crime, binary (true-false) category judgments were inappropriate. Three components of the ERP waveforms were affected by the experimental manipulations. An early positive component was largest to sentences concerning the suspect considered most likely to have committed the crime. A subsequent broad posterior positivity (LPC) also showed significant sentence-type differences, but it was larger to sentences considered probable--whether they were true or false--than to more ambiguous sentences. A third ERP component (N400) was negative at midline electrode sites and peaked at approximately 420 ms. Subjects' truth-value judgments had no effect on the N400. N400 was, however, affected by the subject's task. It was more negative when subjects made graded judgments about truth value than when they made binary true-false judgments. Overall, naturalistic judgments of sentence validity produced a variety of brain responses that reflected different aspects of linguistic decision making.

  11. The cortical chronometry of electrogustatory event-related potentials.

    Science.gov (United States)

    Ohla, Kathrin; Hudry, Julie; le Coutre, Johannes

    2009-09-01

    Electrogustometry (EGM) is the standard tool to assess gustatory functions in clinical environments. The stimulation elicits a percept often described as metallic, sour or salty, also referred to as electric taste. To date, the neuronal mechanisms that underlie electric taste perception are not yet fully understood. Electroencephalographic (EEG) approaches will certainly complement behavioral procedures and, furthermore, extend the understanding of gustatory processing in general and disturbances of gustatory functions in particular. We used anodal pulses applied to the tip of the participants' tongue while EEG was recorded. The major disadvantage of combining EEG and EGM, namely the electrical stimulation artifact, was overcome by means of Independent Component Analysis (ICA), which separated the EGM artifact from the neural portion of the EEG. After artifact correction, we found a largely uncontaminated electrogustatory event-related potential (eGERP) at both individual and group level. Furthermore, source analysis revealed an early involvement of bilateral insular cortices and the adjacent operculi, the areas comprising the primary taste cortex. The procedures, described in detail, pave the way for the eGERP to become an affordable and objective tool for the assessment of taste function, and thus to complement behavioral measures (i.e. EGM detection thresholds). Furthermore, they render the access to different levels of the electrogustatory processing pathway possible and by doing so they may aid the identification and localisation of lesions that cause taste disturbances.

  12. Event Related Potentials Index Rapid Recalibration to Audiovisual Temporal Asynchrony

    Science.gov (United States)

    Simon, David M.; Noel, Jean-Paul; Wallace, Mark T.

    2017-01-01

    Asynchronous arrival of multisensory information at the periphery is a ubiquitous property of signals in the natural environment due to differences in the propagation time of light and sound. Rapid adaptation to these asynchronies is crucial for the appropriate integration of these multisensory signals, which in turn is a fundamental neurobiological process in creating a coherent perceptual representation of our dynamic world. Indeed, multisensory temporal recalibration has been shown to occur at the single trial level, yet the mechanistic basis of this rapid adaptation is unknown. Here, we investigated the neural basis of rapid recalibration to audiovisual temporal asynchrony in human participants using a combination of psychophysics and electroencephalography (EEG). Consistent with previous reports, participant’s perception of audiovisual temporal synchrony on a given trial (t) was influenced by the temporal structure of stimuli on the previous trial (t−1). When examined physiologically, event related potentials (ERPs) were found to be modulated by the temporal structure of the previous trial, manifesting as late differences (>125 ms post second-stimulus onset) in central and parietal positivity on trials with large stimulus onset asynchronies (SOAs). These findings indicate that single trial adaptation to audiovisual temporal asynchrony is reflected in modulations of late evoked components that have previously been linked to stimulus evaluation and decision-making. PMID:28381993

  13. Auditory P300 event-related potential in tobacco smokers.

    Science.gov (United States)

    Guney, Figen; Genc, Bulent Oguz; Kutlu, Ruhusen; Ilhan, Bilge Cetin

    2009-10-01

    The aim of this study was to elucidate the chronic effects of tobacco smoking on the P300, a neurophysiological index of cognitive function. Prospective study participants were recruited from a family medicine polyclinic. We selected 32 right-handed smokers who had smoked more than 15 cigarettes per day, by inhalation, for more than 2 years. The control population consisted of 32 right-handed, age-matched healthy individuals who had never smoked. Event-related potentials (ERPs) were recorded with the auditory "oddball" two-tone discrimination task. The data from the central (Cz) and frontal (Fz) electrodes were analyzed. The P300 and N1 amplitudes at Fz were lower in the study population compared to the control group. The early component of ERP, the measure of mental speed (N1) latency at Fz was prolonged in the study group compared to the controls, possibly because early cognitive processes such as sensory input or initial encoding of sensory information were delayed in this group. For those who smoke, a decreased N1 amplitude might indicate delayed information processing and possibly short-term memory disturbance. Thus, chronic tobacco smoking may produce prefrontal cognitive dysfunction.

  14. Early event related fields during visually evoked pain anticipation.

    Science.gov (United States)

    Gopalakrishnan, Raghavan; Burgess, Richard C; Plow, Ela B; Floden, Darlene P; Machado, Andre G

    2016-03-01

    Pain experience is not only a function of somatosensory inputs. Rather, it is strongly influenced by cognitive and affective pathways. Pain anticipatory phenomena, an important limitation to rehabilitative efforts in the chronic state, are processed by associative and limbic networks, along with primary sensory cortices. Characterization of neurophysiological correlates of pain anticipation, particularly during very early stages of neural processing is critical for development of therapeutic interventions. Here, we utilized magnetoencephalography to study early event-related fields (ERFs) in healthy subjects exposed to a 3 s visual countdown task that preceded a painful stimulus, a non-painful stimulus or no stimulus. We found that the first countdown cue, but not the last cue, evoked critical ERFs signaling anticipation, attention and alertness to the noxious stimuli. Further, we found that P2 and N2 components were significantly different in response to first-cues that signaled incoming painful stimuli when compared to non-painful or no stimuli. The findings indicate that early ERFs are relevant neural substrates of pain anticipatory phenomena and could be potentially serve as biomarkers. These measures could assist in the development of neurostimulation approaches aimed at curbing the negative effects of pain anticipation during rehabilitation. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  15. Sexual Assault Characteristics and Perceptions of Event-Related Distress.

    Science.gov (United States)

    Blayney, Jessica A; Read, Jennifer P

    2015-11-20

    Sexual assault (SA) is a potent psychological stressor, linked to harmful mental health outcomes in both the short- and long-term. Specific assault characteristics can add to the toxicity of SA events. Although research has assessed characteristics of the assault itself (e.g., force, penetration), few studies have examined the larger socioenvironmental context in which SA takes place. This was the purpose of the present study. Young adults (N = 220; 80% female; 54% current students) reported on their most recent SA during college. Cross-sectional associations were tested via structural equation modeling to determine the contributions of socioenvironmental context and assault characteristics in predicting event-related distress. Socioenvironmental context from the most recent assault included assault setting, intoxication at the time of the assault, perpetrator relationship, and prior consensual sexual experiences with the perpetrator. We also examined assault characteristics, including physical force and penetration. Participants reported how upsetting the most recent assault was (a) at the time it occurred and (b) currently. Results revealed differential patterns for socioenvironmental context and assault characteristics based on the timing of distress (past or present). Notably, many of the socioenvironmental factors showed associations with distress above and beyond the powerful effects of physical force and penetration. These findings have important implications for our understanding of the unique factors that contribute to and maintain psychological distress in sexually victimized young adults. © The Author(s) 2015.

  16. Agency attribution: event-related potentials and outcome monitoring.

    Science.gov (United States)

    Bednark, Jeffery G; Franz, Elizabeth A

    2014-04-01

    Knowledge about the effects of our actions is an underlying feature of voluntary behavior. Given the importance of identifying the outcomes of our actions, it has been proposed that the sensory outcomes of self-made actions are inherently different from those of externally caused outcomes. Thus, the outcomes of self-made actions are likely to be more motivationally significant for an agent. We used event-related potentials to investigate the relationship between the perceived motivational significance of an outcome and the attribution of agency in the presence of others. In our experiment, we assessed agency attribution in the presence of another agent by varying the degree of contiguity between participants' self-made actions and the sensory outcome. Specifically, we assessed the feedback correct-related positivity (fCRP) and the novelty P3 measures of an outcome's motivational significance and unexpectedness, respectively. Results revealed that both the fCRP and participants' agency attributions were significantly influenced by action-outcome contiguity. However, when action-outcome contiguity was ambiguous, novelty P3 amplitude was a reliable indicator of agency attribution. Prior agency attributions were also found to influence attribution in trials with ambiguous and low action-outcome contiguity. Participants' use of multiple cues to determine agency is consistent with the cue integration theory of agency. In addition to these novel findings, this study supports growing evidence suggesting that reinforcement processes play a significant role in the sense of agency.

  17. Sentence verification and event-related brain potentials.

    Science.gov (United States)

    Katayama, J; Miyata, Y; Yagi, A

    1987-10-01

    The purpose of this study was to examine whether the decision process affected scalp recorded event-related brain potentials (ERPs). ERPs were recorded while 10 subjects evaluated the veracity of four types of Japanese sentences; true-affirmative (TA), true-negative (TN), false-affirmative (FA), and false-negative (FN). Each sentence was presented visually, one word at a time in the following order: Subject (S); object (O); and verb (V). This order of words, which is normal in Japanese grammar, allowed the ERP waveforms associated with semantic mismatch between the S and O occurring in the middle of the sentence to be separated from those elicited by the decision concerning the sentence's truth or falsity occurring at the end of the sentence. Semantic mismatch was associated with a negative component (N310) following the O-word. In addition, P3s were elicited by sentence final words. Affirmative sentences elicited larger P3s than did negative sentences, and true sentences elicited earlier P3s than did false sentences. P3s were smaller in amplitude when they followed a mismatch between the S and O words. The result suggested that by using Japanese sentences, it may be possible to examine sentence-level rather than word-level processes.

  18. Communication of ALS Patients by Detecting Event-Related Potential

    Science.gov (United States)

    Kanou, Naoyuki; Sakuma, Kenji; Nakashima, Kenji

    Amyotrophic Lateral Sclerosis(ALS) patients are unable to successfully communicate their desires, although their mental capacity is the same as non-affected persons. Therefore, the authors put emphasis on Event-Related Potential(ERP) which elicits the highest outcome for the target visual and hearing stimuli. P300 is one component of ERP. It is positive potential that is elicited when the subject focuses attention on stimuli that appears infrequently. In this paper, the authors focused on P200 and N200 components, in addition to P300, for their great improvement in the rate of correct judgment in the target word-specific experiment. Hence the authors propose the algorithm that specifies target words by detecting these three components. Ten healthy subjects and ALS patient underwent the experiment in which a target word out of five words, was specified by this algorithm. The rates of correct judgment in nine of ten healthy subjects were more than 90.0%. The highest rate was 99.7%. The highest rate of ALS patient was 100.0%. Through these results, the authors found the possibility that ALS patients could communicate with surrounding persons by detecting ERP(P200, N200 and P300) as their desire.

  19. Attention in essential tremor: evidence from event-related potentials.

    Science.gov (United States)

    Pauletti, C; Mannarelli, D; Locuratolo, N; Vanacore, N; De Lucia, M C; Mina, C; Fattapposta, F

    2013-07-01

    Clinically subtle executive dysfunctions have recently been described in essential tremor (ET), though the presence of attentional deficits is still unclear. We investigated the psychophysiological aspects of attention in ET, using event-related potentials (ERPs). Twenty-one non-demented patients with ET and 21 age- and sex-matched healthy controls underwent a psychophysiological evaluation. P300 components and the Contingent Negative Variation (CNV) were recorded. The latencies and amplitudes of the P3a and P3b subcomponents and CNV areas were evaluated. Possible correlations between clinical parameters and ERP data were investigated. P3a latency was significantly longer in the ET group (p memory context-updating process appears to be spared. This selective cognitive dysfunction does not appear to interfere with the attentional set linked to the expectancy evaluated during a complex choice-reaction time task, which is preserved in ET. This multitask psychophysiological approach reveals the presence of a peculiar attentional deficit in patients with ET, thus expanding the clinical features of this disease.

  20. Variation in Event-Related Potentials by State Transitions

    Science.gov (United States)

    Higashi, Hiroshi; Minami, Tetsuto; Nakauchi, Shigeki

    2017-01-01

    The probability of an event's occurrence affects event-related potentials (ERPs) on electroencephalograms. The relation between probability and potentials has been discussed by using a quantity called surprise that represents the self-information that humans receive from the event. Previous studies have estimated surprise based on the probability distribution in a stationary state. Our hypothesis is that state transitions also play an important role in the estimation of surprise. In this study, we compare the effects of surprise on the ERPs based on two models that generate an event sequence: a model of a stationary state and a model with state transitions. To compare these effects, we generate the event sequences with Markov chains to avoid a situation that the state transition probability converges with the stationary probability by the accumulation of the event observations. Our trial-by-trial model-based analysis showed that the stationary probability better explains the P3b component and the state transition probability better explains the P3a component. The effect on P3a suggests that the internal model, which is constantly and automatically generated by the human brain to estimate the probability distribution of the events, approximates the model with state transitions because Bayesian surprise, which represents the degree of updating of the internal model, is highly reflected in P3a. The global effect reflected in P3b, however, may not be related to the internal model because P3b depends on the stationary probability distribution. The results suggest that an internal model can represent state transitions and the global effect is generated by a different mechanism than the one for forming the internal model. PMID:28289380

  1. Event-related potential correlates of mindfulness meditation competence

    Science.gov (United States)

    Atchley, Rachel; Klee, Dan; Memmott, Tabatha; Goodrich, Elena; Wahbeh, Helané; Oken, Barry

    2016-01-01

    Objective This cross-sectional study evaluated event-related potentials (ERPs) across three groups: naïve, novice, and experienced meditators as potential physiological markers of mindfulness meditation competence. Methods Electroencephalographic (EEG) data was collected during a target tone detection task and a Breath Counting task. The Breath Counting task served as the mindfulness meditation condition for the novice and experienced meditator groups. Participants were instructed to respond to target tones with a button press in the first task (Tones), and then ignore the primed tones while breath counting. The primary outcomes were ERP responses to target tones, namely the N2 and P3, as markers of stimulus discrimination and attention, respectively. Results As expected, P3 amplitudes elicited by target tones were attenuated within groups during the Breath Counting task in comparison to the Tones task (p < .001). There was a task by group interaction for P3 (p = .039). Both meditator groups displayed greater change in peak-to-trough P3 amplitudes, with higher amplitudes during the Tones condition and more pronounced reductions in P3 amplitudes during the Breath Counting meditation task in comparison to the naïve group. Conclusions Meditators had stronger P3 amplitude responses to target tones when instructed to attend to the tones, and a greater attenuation of P3 amplitudes when instructed to ignore the same tones during the Breath Counting task. This study introduces the idea of identifying ERP markers as a means of measuring mindfulness meditation competence, and results suggest this may be a valid approach. This information has the potential to improve mindfulness meditation interventions by allowing objective assessment of mindfulness meditation quality. PMID:26850995

  2. Iconic Meaning in Music: An Event-Related Potential Study

    Science.gov (United States)

    Luo, Qiuling; Huang, Hong; Mo, Lei

    2015-01-01

    Although there has been extensive research on the processing of the emotional meaning of music, little is known about other aspects of listeners’ experience of music. The present study investigated the neural correlates of the iconic meaning of music. Event-related potentials (ERP) were recorded while a group of 20 music majors and a group of 20 non-music majors performed a lexical decision task in the context of implicit musical iconic meaning priming. ERP analysis revealed a significant N400 effect of congruency in time window 260-510 ms following the onset of the target word only in the group of music majors. Time-course analysis using 50 ms windows indicated significant N400 effects both within the time window 410-460 ms and 460-510 ms for music majors, whereas only a partial N400 effect during time window 410-460 ms was observed for non-music majors. There was also a trend for the N400 effects in the music major group to be stronger than those in the non-major group in the sub-windows of 310-360ms and 410-460ms. Especially in the sub-window of 410-460 ms, the topographical map of the difference waveforms between congruent and incongruent conditions revealed different N400 distribution between groups; the effect was concentrated in bilateral frontal areas for music majors, but in central-parietal areas for non-music majors. These results imply probable neural mechanism differences underlying automatic iconic meaning priming of music. Our findings suggest that processing of the iconic meaning of music can be accomplished automatically and that musical training may facilitate the understanding of the iconic meaning of music. PMID:26161561

  3. Iconic Meaning in Music: An Event-Related Potential Study.

    Science.gov (United States)

    Cai, Liman; Huang, Ping; Luo, Qiuling; Huang, Hong; Mo, Lei

    2015-01-01

    Although there has been extensive research on the processing of the emotional meaning of music, little is known about other aspects of listeners' experience of music. The present study investigated the neural correlates of the iconic meaning of music. Event-related potentials (ERP) were recorded while a group of 20 music majors and a group of 20 non-music majors performed a lexical decision task in the context of implicit musical iconic meaning priming. ERP analysis revealed a significant N400 effect of congruency in time window 260-510 ms following the onset of the target word only in the group of music majors. Time-course analysis using 50 ms windows indicated significant N400 effects both within the time window 410-460 ms and 460-510 ms for music majors, whereas only a partial N400 effect during time window 410-460 ms was observed for non-music majors. There was also a trend for the N400 effects in the music major group to be stronger than those in the non-major group in the sub-windows of 310-360 ms and 410-460 ms. Especially in the sub-window of 410-460 ms, the topographical map of the difference waveforms between congruent and incongruent conditions revealed different N400 distribution between groups; the effect was concentrated in bilateral frontal areas for music majors, but in central-parietal areas for non-music majors. These results imply probable neural mechanism differences underlying automatic iconic meaning priming of music. Our findings suggest that processing of the iconic meaning of music can be accomplished automatically and that musical training may facilitate the understanding of the iconic meaning of music.

  4. Genetic interaction between the ero1-1 and leu2 mutations in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    López-Mirabal, H Reynaldo; Winther, Jakob R; Kielland-Brandt, Morten C

    2007-01-01

    of the ero1-1 mutation were carried out in a leu2 mutant. The ero1-1 leu2 strain does not grow in standard synthetic complete medium at 30 degrees C, a defect that can be remedied by increasing the L-leucine concentration in the medium or by transforming the ero1-1 leu2 strain with the LEU2 wild-type allele...

  5. Earth Resources Observation and Science (EROS) Center's Earth as Art Image Gallery

    Data.gov (United States)

    National Aeronautics and Space Administration — The Earth Resources Observation and Science (EROS) Center manages this collection of Landsat 7 scenes created for aesthetic purposes rather than scientific...

  6. Effects of the Triaxiality on the Rotation of Celestial Bodies: Application to the Earth, Mars and Eros

    Science.gov (United States)

    Souchay, Jean; Folgueira, Marta; Bouquillon, Sébastien

    2003-10-01

    In this paper we discuss the influence of the triaxiality of a celestial body on its free rotation, i.e. in absence of any external gravitational perturbation. We compare the results obtained through two different analytical formalisms, one established from Andoyer variables by using Hamiltonian theory, the other one from Euler's variables by using Lagrangian equations. We also give a very accurate formulation of the polar motion (polhody) in the case of a small amplitude of this motion. Then, we carry out a numerical integration of the problem, with a Runge-Kutta-Felberg algorithm, and for the two kinds of methods above, that we apply to three different celestial bodies considered as rigid : the Earth, Mars, and Eros. The reason of this choice is that each of this body corresponds to a more or less triaxial shape. In the case of the Earth and Mars we show the good agreement between analytical and numerical determinations of the polar motion, and the amplitude of the effect related to the triaxial shape of the body, which is far from being negligible, with some influence on the polhody of the order of 10 cm for the Earth, and 1 m for Mars. In the case of Eros, we use recent output data given by the NEAR probe, to determine in detail the nature of its free rotational motion, characterized by the presence of important oscillations for the Euler angles due to the particularly large triaxial shape of the asteroid.

  7. Hyperactivity of the Ero1α Oxidase Elicits Endoplasmic Reticulum Stress but No Broad Antioxidant Response

    DEFF Research Database (Denmark)

    Hansen, Henning Gram; Schmidt, Jonas Damgard; Soltoft, Cecilie Lutzen

    2012-01-01

    Oxidizing equivalents for the process of oxidative protein folding in the endoplasmic reticulum (ER) of mammalian cells are mainly provided by the Ero1α oxidase. The molecular mechanisms that regulate Ero1α activity in order to harness its oxidative power are quite well understood. However, the o...

  8. CD-ROM technology at the EROS data center

    Science.gov (United States)

    Madigan, Michael E.; Weinheimer, Mary C.

    1993-01-01

    The vast amount of digital spatial data often required by a single user has created a demand for media alternatives to 1/2" magnetic tape. One such medium that has been recently adopted at the U.S. Geological Survey's EROS Data Center is the compact disc (CD). CD's are a versatile, dynamic, and low-cost method for providing a variety of data on a single media device and are compatible with various computer platforms. CD drives are available for personal computers, UNIX workstations, and mainframe systems, either directly connected, or through a network. This medium furnishes a quick method of reproducing and distributing large amounts of data on a single CD. Several data sets are already available on CD's, including collections of historical Landsat multispectral scanner data and biweekly composites of Advanced Very High Resolution Radiometer data for the conterminous United States. The EROS Data Center intends to provide even more data sets on CD's. Plans include specific data sets on a customized disc to fulfill individual requests, and mass production of unique data sets for large-scale distribution. Requests for a single compact disc-read only memory (CD-ROM) containing a large volume of data either for archiving or for one-time distribution can be addressed with a CD-write once (CD-WO) unit. Mass production and large-scale distribution will require CD-ROM replication and mastering.

  9. Boulders and ponds on the Asteroid 433 Eros

    Science.gov (United States)

    Dombard, Andrew J.; Barnouin, Olivier S.; Prockter, Louise M.; Thomas, Peter C.

    2010-12-01

    There are ˜300 features on the Asteroid 433 Eros that morphologically resemble ponds (flat-floored and sharply embaying the bounding depression in which they sit). Because boulders on Eros are apparently eroding in place and because ponds with associated boulders tend to be larger than ponds without blocks, we propose that ponds form from thermally disaggregated and seismically flattened boulder material, under the assumption that repeated day/night cycling causes material fatigue that leads to erosion of the boulders. Results from a simple boulder emplacement/thermal erosion model with boulders emplaced in a few discrete events (i.e., large impacts) match well the observed size distribution. Under this scenario, the subtle color differences of ponds (somewhat bluer than the rest of the surface) might be due to some combination of less space-weathered material and density stratification of silicate-rich chondrules and more metal-rich matrix from a disaggregated boulder. Volume estimates of ponds derived from NEAR Laser Rangefinder profiles are consistent with what can be supplied by boulders. Ponds are also observed to be concentrated in regions of low slope and high elevation, which suggests the presence of a less mobile regolith and thus a contrast in the resistance to seismic shaking between the pond material and the material that makes up the bounding depression. Future tests include shake-table experiments and temperature cycling (fatigue) of ordinary chondrites to test the thermal erosion mechanism.

  10. Increased event-related potentials and alpha-, beta- and gamma-activity associated with intentional actions

    Directory of Open Access Journals (Sweden)

    Susanne eKarch

    2016-01-01

    Full Text Available Objective: Internally guided actions are defined as being purposeful, self-generated and offering choices between alternatives. Intentional actions are essential to reach individual goals. In previous empirical studies, internally guided actions were predominantly related to functional responses in frontal and parietal areas. The aim of the present study was to distinguish event-related potentials and oscillatory responses of intentional actions and externally guided actions. In addition, we compared neurobiological findings of the decision which action to perform with those referring to the decision whether or not to perform an action. Methods: Twenty-eight subjects participated in adapted go/nogo paradigms, including a voluntary selection condition allowing participants to [1] freely decide whether to press the response button or [2] to decide whether they wanted to press the response button with the right index finger or the left index finger. Results: The reaction times were increased when participants freely decided whether and how they wanted to respond compared to the go condition. Intentional processes were associated with a fronto-centrally located N2 and P3 potential. N2 and P3 amplitudes were increased during intentional actions compared to instructed responses (go. In addition, increased activity in the alpha-, beta- and gamma-frequency range was shown during voluntary behaviour rather than during externally-guided responses. Conclusion: These results may indicate that an additional cognitive process is needed for intentional actions compared to instructed behaviour. However, the neural responses were comparatively independent of the kind of decision that was made (1. decision which action to perform; 2. decision whether or not to perform an action. Significance: The study demonstrates the importance of fronto-central alpha-, beta- and gamma oscillations for voluntary behaviour.

  11. State of consciousness and ERP (event-related potential measures. Diagnostic and prognostic value of electrophysiology for disorders of consciousness

    Directory of Open Access Journals (Sweden)

    Michela Balconi

    2011-11-01

    Full Text Available Disorders of consciousness were amply studied in the recent years. At this regards new methodologies and technologies were applied to explore the diagnostic and prognostic criteria that may be applied to the patients. Specifically electrophysiological measures were used to verify the degree of awareness and responsiveness in coma, vegetative states (VS, minimal consciousness state (MC, and locked-in syndrome (LI. Recently, ERPs (event-related potentials were adopted to integrate the classical neuroimaging measures. Between the others, MMN (mismatch negativity and P300 deflections were found to represent a consistent index of the present state of consciousness and to be predictive of successive modifications of this state. Also frequency-based EEG measures, such as brain oscillations, were revealed to be relevant marker of consciousness and awareness, able to predict the future evolution of pathology.

  12. Sylvia Plath - a woman between Eros and Thanatos

    Directory of Open Access Journals (Sweden)

    Barbara Galle

    2005-12-01

    Full Text Available The opposition between the Hughes family  and the radical feminists led to the emergence of two diametrically opposite Plath  myths: a mentally disturbed, manipulative woman, unstoppably driven towards suicide, or an innocent victim of a treacherous husband? Both sides interpret Plath's life and works in view of her untimely  death, neglecting the underlying life force that pervades her poetry and prose. Relying on the psychoanalytical theory of instincts, the author shows how Eros complements and even makes use of Thanatos on different levels of Plath's writing:  on the level of language asa meaningful structure, on the level of meaning, and in the function of language as therapy. The duality of instics is particulary evident in Sloveirian criticism; where the physicar  and temporal distance from political scandal enabled the development oftwo distinct critical currents: one following Hughes's morbid determinism, the other concentrating on Plath's intelligence and joyful observation of nature.

  13. JOSÉ DONOSO O EL EROS DE LA HOMOFOBIA

    Directory of Open Access Journals (Sweden)

    Miguel Ángel Náter

    2006-04-01

    Full Text Available El artículo destaca la importancia de los "Papeles de Donoso", custodiados en la Universidad de Iwoa, en relación con las ideas de Julio Ortega sobre los mismos, vertidas en el periódico La Tercera de Chile. Además, se realiza una lectura de la homofobia como expresión del eros subrepticio en las novelas El lugar sin límites y El obsceno pájaro de la noche. En contraste con las exposiciones homoeróticas que Ortega señala en los documentos de Donoso, los narradores de las dos novelas más destacadas del escritor chileno expresan un rechazo continuo hacia los personajes marginales, o bien exponen la sodomía como un forma de expresar la inferioridad del subalternoThis article underscores the significance of José Donoso's "Papers", in the custody of Iowa University, in connection whith Julio Ortega's ideas about them, as made known by the newpaper "La Tercera", in Chile. In addition, a reading of homophobia as expression of a surreptitious eros, is made in the novels "El lugar sin límites" and in "El obsceno pájaro de la noche". In contrast to the homoerotic discourse that Ortega detects in Donoso, the narrators in the two best known novels of the Chilean writer express a constant rejection of the marginal characters, or otherwise expose sodomy as a form which expresses the inferiority of the underling

  14. Neurodynamic oscillators

    Science.gov (United States)

    Espinosa, Ismael; Gonzalez, Hortensia; Quiza, Jorge; Gonazalez, J. Jesus; Arroyo, Ruben; Lara, Ritaluz

    1995-01-01

    Oscillation of electrical activity has been found in many nervous systems, from invertebrates to vertebrates including man. There exists experimental evidence of very simple circuits with the capability of oscillation. Neurons with intrinsic oscillation have been found and also neural circuits where oscillation is a property of the network. These two types of oscillations coexist in many instances. It is nowadays hypothesized that behind synchronization and oscillation there is a system of coupled oscillators responsible for activities that range from locomotion and feature binding in vision to control of sleep and circadian rhythms. The huge knowledge that has been acquired on oscillators from the times of Lord Rayleigh has made the simulation of neural oscillators a very active endeavor. This has been enhanced with more recent physiological findings about small neural circuits by means of intracellular and extracellular recordings as well as imaging methods. The future of this interdisciplinary field looks very promising; some researchers are going into quantum mechanics with the idea of trying to provide a quantum description of the brain. In this work we describe some simulations using neuron models by means of which we form simple neural networks that have the capability of oscillation. We analyze the oscillatory activity with root locus method, cross-correlation histograms, and phase planes. In the more complicated neural network models there is the possibility of chaotic oscillatory activity and we study that by means of Lyapunov exponents. The companion paper shows an example of that kind.

  15. ERPWAVELAB A toolbox for multi-channel analysis of time-frequency transformed event related potentials

    DEFF Research Database (Denmark)

    Mørup, Morten; Hansen, Lars Kai; Arnfred, Sidse M.

    2006-01-01

    The toolbox 'ERPWAVELAB' is developed for multi-channel time-frequency analysis of event related activity of EEG and MEG data. The toolbox provides tools for data analysis and visualization of the most commonly used measures of time-frequency transformed event related data as well as data...

  16. The Event-Related Low-Frequency Activity of Highly and Average Intelligent Children

    Science.gov (United States)

    Liu, Tongran; Shi, Jiannong; Zhao, Daheng; Yang, Jie

    2008-01-01

    Using time-frequency analysis techniques to investigate the event-related low-frequency (delta: 0.5-4 Hz; theta: 4-8 Hz) activity of auditory event-related potentials (ERPs) data of highly and average intelligent children, 18 intellectually gifted children, and 18 intellectually average children participated the present study. Present findings…

  17. Quantum Oscillators

    CERN Document Server

    Blaise, Paul

    2011-01-01

    An invaluable reference for an overall but simple approach to the complexity of quantum mechanics viewed through quantum oscillators Quantum oscillators play a fundamental role in many areas of physics; for instance, in chemical physics with molecular normal modes, in solid state physics with phonons, and in quantum theory of light with photons. Quantum Oscillators is a timely and visionary book which presents these intricate topics, broadly covering the properties of quantum oscillators which are usually dispersed in the literature at varying levels of detail and often combined with other p

  18. Steady-state visual evoked potentials can be explained by temporal superposition of transient event-related responses.

    Directory of Open Access Journals (Sweden)

    Almudena Capilla

    Full Text Available BACKGROUND: One common criterion for classifying electrophysiological brain responses is based on the distinction between transient (i.e. event-related potentials, ERPs and steady-state responses (SSRs. The generation of SSRs is usually attributed to the entrainment of a neural rhythm driven by the stimulus train. However, a more parsimonious account suggests that SSRs might result from the linear addition of the transient responses elicited by each stimulus. This study aimed to investigate this possibility. METHODOLOGY/PRINCIPAL FINDINGS: We recorded brain potentials elicited by a checkerboard stimulus reversing at different rates. We modeled SSRs by sequentially shifting and linearly adding rate-specific ERPs. Our results show a strong resemblance between recorded and synthetic SSRs, supporting the superposition hypothesis. Furthermore, we did not find evidence of entrainment of a neural oscillation at the stimulation frequency. CONCLUSIONS/SIGNIFICANCE: This study provides evidence that visual SSRs can be explained as a superposition of transient ERPs. These findings have critical implications in our current understanding of brain oscillations. Contrary to the idea that neural networks can be tuned to a wide range of frequencies, our findings rather suggest that the oscillatory response of a given neural network is constrained within its natural frequency range.

  19. Earth Resources Observation and Science (EROS) Center's Earth as Art Image Gallery 3

    Data.gov (United States)

    National Aeronautics and Space Administration — The Earth Resources Observation and Science (EROS) Center manages the Earth as Art Three exhibit, which provides fresh and inspiring glimpses of different parts of...

  20. Earth Resources Observation and Science (EROS) Center's Journey of Lewis and Clark Gallery

    Data.gov (United States)

    National Aeronautics and Space Administration — The Earth Resources Observation and Science (EROS) Center manages the this gallery of Landsat-derived images of one of the most remarkable and productive scientific...

  1. Earth Resources Observation and Science (EROS) Center's Earth as Art Image Gallery 2

    Data.gov (United States)

    National Aeronautics and Space Administration — The Earth Resources Observation and Science (EROS) Center manages this collection of forty-five new scenes developed for their aesthetic beauty, rather than for...

  2. La sfida al labirinto sessuale. L’eros nell’opera di Italo Calvino

    National Research Council Canada - National Science Library

    Elio Baldi

    2012-01-01

    The Challenge of the Sexual Labyrinth Sensuality in the Work of Italo CalvinoIn this article, the novels, stories and essays of Italo Calvino are being studied from the perspective of sensuality and Eros...

  3. PAO Image Gallery = Public Affairs Photos of EROS Projects: 1972 - 2005

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The EROS Image Gallery collection is composed of a wide variety of images ranging from low altitude aircraft to satellite and NASA imagery; oblique photographs and...

  4. Understanding Regolith Distribution on 433 Eros Using Analyses of Pit Chains and Grooves

    Science.gov (United States)

    Wyrick, D. Y.; Buczkowski, D. L.

    2006-03-01

    The distribution of pit chains and grooves on Eros provides clues to the internal structure and the spatial distribution of regolith. Additional analyses of pit slopes and volumes provide information on regolith thickness and mechanical properties.

  5. Introducing the event related fixed interval area (ERFIA) multilevel technique: a method to analyze the complete epoch of event-related potentials at single trial level

    NARCIS (Netherlands)

    Vossen, C.J.; Vossen, H.G.M.; Marcus, M.A.E.; van Os, J.; Lousberg, R.

    2013-01-01

    In analyzing time-locked event-related potentials (ERPs), many studies have focused on specific peaks and their differences between experimental conditions. In theory, each latency point after a stimulus contains potentially meaningful information, regardless of whether it is peak-related. Based on

  6. Chemical Oscillations

    Indian Academy of Sciences (India)

    processes at the cellular level like the glycolytic pathway, peroxi- dase-catalysed reaction or the biosynthesis of certain proteins. A systematic study of oscillating chemical reactions is of consider- able interest, since these oscillating reactions can be used as prototype examples of the behaviours possible in reactions gov-.

  7. Event Relation Recognition by Multi Part of Speech Association Distribution Characteristics

    Directory of Open Access Journals (Sweden)

    Han Chao

    2017-01-01

    Full Text Available Event relation recognition, as one of natural language processing technologies, faces information stream of texts detecting event relation. By analyzing the influence of the words of different parts of speech on the relevance of events. And use the form of lexical chain to extract and store the relevant vocabulary between events, this paper propose an event relation recognization method based on lexical chain to detect latent semantic relation between events: whether events hold logical relation or not. Cornpared with the method based on dependency cue inference, the proposed method achieves 7. 68% improvement.

  8. Affective visual event-related potentials: Arousal, valence, and repetition effects for normal and distorted pictures

    OpenAIRE

    Rozenkrants, Bella; Olofsson, Jonas K.; Polich, John

    2007-01-01

    Event-related potentials (ERPs) were used to assess arousal (low, high), valence (negative, positive), and stimulus repetition effects for normal and distorted images from the International Affective Pictures System (IAPS). Distorted stimuli were constructed by dividing each image into 108 one cm squares and rearranging the segments randomly to produce a “scrambled” picture. Event-related potentials (ERPs) were elicited by presenting the normal and scrambled images as target stimuli, with a r...

  9. Fibonacci oscillators

    Energy Technology Data Exchange (ETDEWEB)

    Arik, M. (Istanbul Technical Univ. (Turkey). Dept. of Mathematics Bogazici Univ., Istanbul (Turkey). Dept. of Physics); Demircan, E.; Turgut, T. (Texas Univ., Austin, TX (United States). Dept. of Physics); Ekinci, L.; Mungan, M. (Bogazici Univ., Istanbul (Turkey). Dept. of Physics)

    1992-07-01

    We discuss the properties of oscillators whose spectrum is given by a generalized Fibonacci sequence. The properties include: Invariance under the unitary quantum group, generalized angular momentum, coherent states and difference calculus, relativistic interpretation. (orig.).

  10. Understanding EROS2 observations toward the spiral arms within a classical Galactic model framework

    Science.gov (United States)

    Moniez, M.; Sajadian, S.; Karami, M.; Rahvar, S.; Ansari, R.

    2017-08-01

    Aims: EROS (Expérience de Recherche d'Objets Sombres) has searched for microlensing toward four directions in the Galactic plane away from the Galactic center. The interpretation of the catalog optical depth is complicated by the spread of the source distance distribution. We compare the EROS microlensing observations with Galactic models (including the Besançon model), tuned to fit the EROS source catalogs, and take into account all observational data such as the microlensing optical depth, the Einstein crossing durations, and the color and magnitude distributions of the catalogued stars. Methods: We simulated EROS-like source catalogs using the HIgh-Precision PARallax COllecting Satellite (Hipparcos) database, the Galactic mass distribution, and an interstellar extinction table. Taking into account the EROS star detection efficiency, we were able to produce simulated color-magnitude diagrams that fit the observed diagrams. This allows us to estimate average microlensing optical depths and event durations that are directly comparable with the measured values. Results: Both the Besançon model and our Galactic model allow us to fully understand the EROS color-magnitude data. The average optical depths and mean event durations calculated from these models are in reasonable agreement with the observations. Varying the Galactic structure parameters through simulation, we were also able to deduce contraints on the kinematics of the disk, the disk stellar mass function (at a few kpc distance from the Sun), and the maximum contribution of a thick disk of compact objects in the Galactic plane (Mthickglobal fit taking into account all the observables (from the color-magnitude diagrams and microlensing observations) shows the validity of the Galactic models. Our tests with the parameters excursions show the unique sensitivity of the microlensing data to the kinematical parameters and stellar initial mass function. http://www.lal.in2p3.fr/recherche/eros

  11. Near Earth Asteroid Rendezvous (NEAR) Revised Eros Orbit Phase Trajectory Design

    Science.gov (United States)

    Helfrich, J; Miller, J. K.; Antreasian, P. G.; Carranza, E.; Williams, B. G.; Dunham, D. W.; Farquhar, R. W.; McAdams, J. V.

    1999-01-01

    Trajectory design of the orbit phase of the NEAR mission involves a new process that departs significantly from those procedures used in previous missions. In most cases, a precise spacecraft ephemeris is designed well in advance of arrival at the target body. For NEAR, the uncertainty in the dynamic environment around Eros does not allow the luxury of a precise spacecraft trajectory to be defined in advance. The principal cause of this uncertainty is the limited knowledge oi' the gravity field a,-id rotational state of Eros. As a result, the concept for the NEAR trajectory design is to define a number of rules for satisfying spacecraft, mission, and science constraints, and then apply these rules to various assumptions for the model of Eros. Nominal, high, and low Eros mass models are used for testing the trajectory design strategy and to bracket the ranges of parameter variations that are expected upon arrival at the asteroid. The final design is completed after arrival at Eros and determination of the actual gravity field and rotational state. As a result of the unplanned termination of the deep space rendezvous maneuver on December 20, 1998, the NEAR spacecraft passed within 3830 km of Eros on December 23, 1998. This flyby provided a brief glimpse of Eros, and allowed for a more accurate model of the rotational parameters and gravity field uncertainty. Furthermore, after the termination of the deep space rendezvous burn, contact with the spacecraft was lost and the NEAR spacecraft lost attitude control. During the subsequent gyrations of the spacecraft, hydrazine thruster firings were used to regain attitude control. This unplanned thruster activity used Much of the fuel margin allocated for the orbit phase. Consequently, minimizing fuel consumption is now even more important.

  12. EROs and the Large-Scale Structure of High-z Ellipticals

    Science.gov (United States)

    Daddi, E.; Zamorani, G.; Cimatti, A.; Röttgering, H.; Renzini, A.

    Daddi et al. (2000) reported the detection of strong angular clustering of extremely red galaxies (EROs, defined as objects with R - K > 5) with K ≲ 19. The EROs angular 2-point correlation function were remarkably well fitted by a "standard" power law with exponent δ = -0.8 but with a very large amplitude, a factor of 10 larger than that of the field galaxy population at the same depth. The clustering strength was found to smoothly increase with the R - K color. This was interpreted as evidence that the bulk of EROs is made of ellipticals that produce as expected a strong clustering signal, and this important conclusion is confirmed by independent indications (Cimatti et al. 1999, Moriondo, Cimatti & Daddi 2000, Stiavelli & Treu 2000, Cimatti 2000). In fact, the use of simple test redshift distributions for the inversion of the Limber equation, shows that the ERO angular clustering necessarily imply a large correlation length r 0: for example to obtain r_0 ˜ 5 h^{-1} Mpc (comoving units) EROs should be confined in an extremely narrow and unrealistic redshift range of Δ z ˜ 0.1 - 0.2. Therefore much larger r 0 values are required, values unlikely to be due to a star-forming population of galaxies.

  13. Etičko razumijevanje erosa u Levinasovoj filozofiji / Ethical Understanding of Eros in Levinas’ Philosophy

    Directory of Open Access Journals (Sweden)

    Kristina Bojanović

    2016-11-01

    Full Text Available In this paper I will analyze one of the central ideas of Emmanuel Levinas – a phenomenon of eros, and try to show why erotic relation in his thought is designated as exemplary ethical relation, and how it is associated with other ideas introduced by this philosopher. I will provide a general overview of Levinas’ philosophy, with emphasis on his ‘showdown’ with traditional Western ontology and the establishment of ethics as first philosophy, in order to come to the main part of the analysis, in which I will consider the ambiguity and paradoxicality of phenomenon of eros, and the concept of feminine as principal in erotic relation. Also, I will try to explain and differentiate some more phenomena necessary for understanding of eros, such as caress and fecundity. In conclusion I will make a concise distinction between eros in Levinas and Plato, as well as distinction between eros and agape, but also I will clarify the erotic relation as asymmetric intersubjective relation within the Levinas’ philosophical project.

  14. Iconografía textil q'ero como texto: leyendo el rombo dualista Hatun Inti

    Directory of Open Access Journals (Sweden)

    1994-01-01

    Full Text Available L'ICONOGRAPHIE TEXTILE Q'ERO VUE EN TANT QUE TEXTE: LECTURE DU LOSANGE DUALISTE HATUN INTI. Les Q'ero, ainsi que les autres natifs du département de Cusco, lisent le motif géométrique dualiste Hatun Inti en l'associant à des conceptions spatiales. Les éléments graphiques qui forment ce losange ont des noms et des significations spécifiques, et créent un véritable lexique graphique. Los Q’ero y otros nativos del departamento del Cusco leen el motivo geométrico dualista Hatun Inti, con referencia a concepciones espaciales. Los elementos gráficos que forman este rombo toman nombres y significados específicos, creando un verdadero léxico gráfico. Q'ERO TEXTILE ICONOGRAPHY PERCEIVED AS TEXT: READING THE HALVED HATUN INTI. The Q’ero and other natives who live in the Department of Cusco read halved diamond motif as it refers to spatial concepts. The graphic elements which form this motif have specific names and meanings, creating a true graphic lexicon.

  15. Long latency event-related potentials (P300) in gifted children.

    Science.gov (United States)

    Martin, F; Delpont, E; Suisse, G; Richelme, C; Dolisi, C

    1993-01-01

    In children, P3 latency decreases with increasing age. This decrease could be linked with the maturation of cognitive processes. According to this hypothesis, event-related potentials P3 were recording in gifted children to research an electrophysiological correlation with the mental precocity. Auditory long latency event-related potentials were recorded in 10 gifted children (IQs over 140) and 23 control subjects. The part of variance related to age was extracted by comparing deviations from regression line as a function of age. Stimulus-evoked N1 component latency was not statistically different in the two populations. Event-related P3 component latency was significantly shorter in the gifted children at Cz (P children.

  16. Prominence Oscillations

    Directory of Open Access Journals (Sweden)

    Iñigo Arregui

    2012-04-01

    Full Text Available Prominences are intriguing, but poorly understood, magnetic structures of the solar corona. The dynamics of solar prominences has been the subject of a large number of studies, and of particular interest is the study of prominence oscillations. Ground- and space-based observations have confirmed the presence of oscillatory motions in prominences and they have been interpreted in terms of magnetohydrodynamic (MHD waves. This interpretation opens the door to perform prominence seismology, whose main aim is to determine physical parameters in magnetic and plasma structures (prominences that are difficult to measure by direct means. Here, we review the observational information gathered about prominence oscillations as well as the theoretical models developed to interpret small amplitude oscillations and their temporal and spatial attenuation. Finally, several prominence seismology applications are presented.

  17. Endoplasmic reticulum transport of glutathione by Sec61 is regulated by Ero1 and Bip

    DEFF Research Database (Denmark)

    Ponsero, Alise J.; Igbaria, Aeid; Darch, Maxwell A.

    2017-01-01

    In the endoplasmic reticulum (ER), Ero1 catalyzes disulfide bond formation and promotes glutathione (GSH) oxidation to GSSG. Since GSSG cannot be reduced in the ER, maintenance of the ER glutathione redox state and levels likely depends on ER glutathione import and GSSG export. We used quantitative...... GSH and GSSG biosensors to monitor glutathione import into the ER of yeast cells. We found that glutathione enters the ER by facilitated diffusion through the Sec61 protein-conducting channel, while oxidized Bip (Kar2) inhibits transport. Increased ER glutathione import triggers H2O2-dependent Bip...... oxidation through Ero1 reductive activation, which inhibits glutathione import in a negative regulatory loop. During ER stress, transport is activated by UPR-dependent Ero1 induction, and cytosolic glutathione levels increase. Thus, the ER redox poise is tuned by reciprocal control of glutathione import...

  18. The transformative potential of realigning Agape and Eros in the continued development of nursing's role.

    Science.gov (United States)

    Valentine-Maher, Sarah

    2008-01-01

    Nursing may reach its highest potential when there is an integration of Agape love and Eros love within nursing. That is, an ontological framework from which service and giving of the self are aligned with creative power and development of the self. The concepts of Eros and Agape give the nurse tools to understand the contradictions of nursing and to find increased purpose, peace, and strength in her own work. For the field of nursing, the concepts of Eros and Agape offer a pathway to redefining a heroic role of service. Such a redefined role may help nursing become increasingly responsive to the true reality of human needs, from direct contact with a patient to involvement in international health.

  19. EROS Data Center Landsat digital enhancement techniques and imagery availability

    Science.gov (United States)

    Rohde, Wayne G.; Lo, Jinn Kai; Pohl, Russell A.

    1978-01-01

    The US Geological Survey's EROS Data Center (EDC) is experimenting with the production of digitally enhanced Landsat imagery. Advanced digital image processing techniques are used to perform geometric and radiometric corrections and to perform contrast and edge enhancements. The enhanced image product is produced from digitally preprocessed Landsat computer compatible tapes (CCTs) on a laser beam film recording system. Landsat CCT data have several geometric distortions which are corrected when NASA produces the standard film products. When producing film images from CCT's, geometric correction of the data is required. The EDC Digital Image Enhancement System (EDIES) compensates for geometric distortions introduced by Earth's rotation, variable line length, non-uniform mirror scan velocity, and detector misregistration. Radiometric anomalies such as bad data lines and striping are common to many Landsat film products and are also in the CCT data. Bad data lines or line segments with more than 150 contiguous bad pixels are corrected by inserting data from the previous line in place of the bad data. Striping, caused by variations in detector gain and offset, is removed with a destriping algorithm applied after digitally enhancing the data. Image enhancement is performed by applying a linear contrast stretch and an edge enhancement algorithm. The linear contrast enhancement algorithm is designed to expand digitally the full range of useful data recorded on the CCT over the range of 256 digital counts. This minimizes the effect of atmospheric scattering and saturates the relative brightness of highly reflecting features such as clouds or snow. It is the intent that no meaningful terrain data are eliminated by the digital processing. The edge enhancement algorithm is designed to enhance boundaries between terrain features that exhibit subtle differences in brightness values along edges of features. After the digital data have been processed, data for each Landsat band

  20. The "Mozart effect": an electroencephalographic analysis employing the methods of induced event-related desynchronization/synchronization and event-related coherence.

    Science.gov (United States)

    Jausovec, Norbert; Habe, Katarina

    2003-01-01

    The event-related responses of 18 individuals were recorded while they were listening to 3 music clips of 6 s duration which were repeated 30 times each. The music clips differed in the level of their complex structure, induced mood, musical tempo and prominent frequency. They were taken from Mozart's sonata (K. 448), and Brahms' Hungarian dance (no. 5). The third clip was a simplified version of the theme taken from Haydn's symphony (no. 94) played by a computer synthesizer. Significant differences in induced event-related desynchronization between the 3 music clips were only observed in the lower-1 alpha band which is related to attentional processes. A similar pattern was observed for the coherence measures. While respondents listened to the Mozart clip, coherence in the lower alpha bands increased more, whereas in the gamma band a less pronounced increase was observed as compared with the Brahms and Haydn clips. The clustering of the three clips based on EEG measures distinguished between the Mozart clip on the one hand, and the Haydn and Brahms clips on the other, even though the Haydn and Brahms clips were at the opposite extremes with regard to the mood they induced in listeners, musical tempo, and complexity of structure. This would suggest that Mozart's music--with no regard to the level of induced mood, musical tempo and complexity--influences the level of arousal. It seems that modulations in the frequency domain of Mozart's sonata have the greatest influence on the reported neurophysiological activity.

  1. Impact-induced seismic activity on asteroid 433 Eros: a surface modification process.

    Science.gov (United States)

    Richardson, James E; Melosh, H Jay; Greenberg, Richard

    2004-11-26

    High-resolution images of the surface of asteroid 433 Eros revealed evidence of downslope movement of a loose regolith layer, as well as the degradation and erasure of small impact craters (less than approximately 100 meters in diameter). One hypothesis to explain these observations is seismic reverberation after impact events. We used a combination of seismic and geomorphic modeling to analyze the response of regolith-covered topography, particularly craters, to impact-induced seismic shaking. Applying these results to a stochastic cratering model for the surface of Eros produced good agreement with the observed size-frequency distribution of craters, including the paucity of small craters.

  2. Chromosperic oscillations

    NARCIS (Netherlands)

    Rutten, R.J.

    1999-01-01

    This review concentrates on the quiet-Sun chromosphere. Its internetwork areas are dynamically dominated by the so-called chromospheric three-minute oscillation. They are interpretationally dominated by the so-called Ca II K 2V and H 2V grains. The main points of this review are that the one

  3. Importance of baseline in Event-Related Desynchronization during imaging-observation

    NARCIS (Netherlands)

    Tangwiriyasakul, Chayanin; Verhagen, R.; Rutten, Wim; van Putten, Michel Johannes Antonius Maria

    2011-01-01

    Introduction: To design a neurofeedback system (NF system) for clinical purposes (e.g. stroke rehabilitation) using imaging-observation of motor movements. Event-Related Desynchronization (ERD) of the mu rhythm (8-13 Hz) is vital to indicate the engagement between the patient’s brain and the NF

  4. Interactions Between Pre-Processing and Classification Methods for Event-Related-Potential Classification

    NARCIS (Netherlands)

    Farquhar, J.D.R.; Hill, N.J.

    2013-01-01

    Detecting event related potentials (ERPs) from single trials is critical to the operation of many stimulus-driven brain computer interface (BCI) systems. The low strength of the ERP signal compared to the noise (due to artifacts and BCI irrelevant brain processes) makes this a challenging signal

  5. Event-related Potentials Reflecting the Processing of Phonological Constraint Violations

    NARCIS (Netherlands)

    Domahs, Ulrike; Kehrein, Wolfgang; Knaus, Johannes; Wiese, Richard; Schlesewsky, Matthias

    2009-01-01

    Flow are violations of phonological constraints processed in word comprehension? The present article reports the results of ail event-related potentials (ERP) Study oil a phonological constraint of German that disallows identical segments within it syllable or word (CC(i)VC(i)). We examined three

  6. Single-trial normalization for event-related spectral decomposition reduces sensitivity to noisy trials

    Directory of Open Access Journals (Sweden)

    Romain eGrandchamp

    2011-09-01

    Full Text Available In EEG research, the classical Event-Related Potential (ERP model often proves to be a limited method when studying complex brain dynamics. For this reason, spectral techniques adapted from signal processing such as Event-Related Spectral Perturbation (ERSP – and its variant ERS (Event-Related Synchronization and ERD (Event-Related Desynchronization – have been used over the past 20-years. They represent average spectral changes in response to a stimulus.These spectral methods do not have strong consensus for comparing pre and post-stimulus activity. When computing ERSP, pre-stimulus baseline removal is usually performed after averaging the spectral estimate of multiple trials. Correcting the baseline of each single-trial prior to averaging spectral estimates is an alternative baseline correction method. However, we show that this method leads to positively skewed post-stimulus ERSP values. We eventually present new single-trial based ERSP baseline correction methods that perform trial normalization or centering prior to applying classical baseline correction methods. We show that single-trial correction methods minimize the contribution of artifactual data trials with high-amplitude spectral estimates and are robust to outliers when performing statistical inference testing. We then characterize these methods in terms of their time-frequency responses and behavior when performing statistical inference testing compared to classical ERSP methods.

  7. Do U Txt? Event-Related Potentials to Semantic Anomalies in Standard and Texted English

    Science.gov (United States)

    Berger, Natalie I.; Coch, Donna

    2010-01-01

    Texted English is a hybrid, technology-based language derived from standard English modified to facilitate ease of communication via instant and text messaging. We compared semantic processing of texted and standard English sentences by recording event-related potentials in a classic semantic incongruity paradigm designed to elicit an N400 effect.…

  8. Habituation : an event-related potential and dipole source analysis study

    NARCIS (Netherlands)

    Bruin, KJ; Kenemans, JL; Verbaten, MN; Van der Heijden, AHC

    The goal of this study was to investigate habituation processes in the brain, and in particular, to identify the brain structures involved in these processes. Therefore, event-related potentials (ERPs) were recorded in response to a series of repeated, task-irrelevant, salient stimuli presented

  9. Event-related potential responses to love-related facial stimuli

    NARCIS (Netherlands)

    S.J.E. Langeslag (Sandra); B.M. Jansma (Bernadette); I.H.A. Franken (Ingmar); J.W. van Strien (Jan)

    2007-01-01

    textabstractIn event-related potential (ERPs) studies, emotional stimuli usually elicit an enhanced late positive potential (LPP), which is assumed to reflect motivated attention. However, whether a stimulus elicits emotional responses may depend on the individual's state, such as experiencing

  10. Representations in human visual short-term memory : an event-related brain potential study

    NARCIS (Netherlands)

    Klaver, P; Smid, HGOM; Heinze, HJ

    1999-01-01

    Behavioral measures and event-related potentials (ERPs) were recorded from 12 subjects while performing three delayed matching-to-sample tasks. The task instructions indicated whether stimulus locations, shapes or conjunctions of locations and shapes had to be memorized and matched against a probe.

  11. (De-)Accentuation and the Processing of Information Status: Evidence from Event-Related Brain Potentials

    Science.gov (United States)

    Baumann, Stefan; Schumacher, Petra B.

    2012-01-01

    The paper reports on a perception experiment in German that investigated the neuro-cognitive processing of information structural concepts and their prosodic marking using event-related brain potentials (ERPs). Experimental conditions controlled the information status (given vs. new) of referring and non-referring target expressions (nouns vs.…

  12. Snake scales, partial exposure, and the Snake Detection Theory: A human event-related potentials study

    NARCIS (Netherlands)

    J.W. van Strien (Jan); L.A. Isbell (Lynne A.)

    2017-01-01

    textabstractStudies of event-related potentials in humans have established larger early posterior negativity (EPN) in response to pictures depicting snakes than to pictures depicting other creatures. Ethological research has recently shown that macaques and wild vervet monkeys respond strongly to

  13. Atypical Brain Responses to Reward Cues in Autism as Revealed by Event-Related Potentials

    Science.gov (United States)

    Kohls, Gregor; Peltzer, Judith; Schulte-Ruther, Martin; Kamp-Becker, Inge; Remschmidt, Helmut; Herpertz-Dahlmann, Beate; Konrad, Kerstin

    2011-01-01

    Social motivation deficit theories suggest that children with autism do not properly anticipate and appreciate the pleasure of social stimuli. In this study, we investigated event-related brain potentials evoked by cues that triggered social versus monetary reward anticipation in children with autism. Children with autism showed attenuated P3…

  14. Predicting Reading Growth with Event-Related Potentials: Thinking Differently about Indexing "Responsiveness"

    Science.gov (United States)

    Lemons, Christopher J.; Key, Alexandra P. F.; Fuchs, Douglas; Yoder, Paul J.; Fuchs, Lynn S.; Compton, Donald L.; Williams, Susan M.; Bouton, Bobette

    2010-01-01

    The purpose of this study was to determine if event-related potential (ERP) data collected during three reading-related tasks (Letter Sound Matching, Nonword Rhyming, and Nonword Reading) could be used to predict short-term reading growth on a curriculum-based measure of word identification fluency over 19 weeks in a sample of 29 first-grade…

  15. Dissociation of Event-Related Potentials Indexing Arousal and Semantic Cohesion During Emotional Word Encoding

    Science.gov (United States)

    Dillon, Daniel G.; Cooper, Julie J.; Grent-'t-Jong, Tineke; Woldorff, Marty G.; LaBar, Kevin S.

    2006-01-01

    Event-related potential (ERP) studies have shown that emotional stimuli elicit greater amplitude late positive-polarity potentials (LPPs) than neutral stimuli. This effect has been attributed to arousal, but emotional stimuli are also more semantically coherent than uncategorized neutral stimuli. ERPs were recorded during encoding of positive,…

  16. Word Learning and Individual Differences in Word Learning Reflected in Event-Related Potentials

    Science.gov (United States)

    Perfetti, Charles A.; Wlotko, Edward W.; Hart, Lesley A.

    2005-01-01

    Adults learned the meanings of rare words (e.g., gloaming) and then made meaning judgments on pairs of words. The 1st word was a trained rare word, an untrained rare word, or an untrained familiar word. Event-related potentials distinguished trained rare words from both untrained rare and familiar words, first at 140 ms and again at 400-600 ms…

  17. Event-related potentials reflecting the processing of phonological constraint violations

    NARCIS (Netherlands)

    Domahs, U.; Kehrein, W.; Knaus, J.; Wiese, R.; Schlesewsky, M.

    2009-01-01

    How are violations of phonological constraints processed in word comprehension? The present article reports the results of an event-related potentials (ERP) study on a phonological constraint of German that disallows identical segments within a syllable or word (CC iVCi). We examined three types of

  18. Event-related potential evidence on the influence of accentuation in spoken discourse comprehension in Chinese

    NARCIS (Netherlands)

    Li, X.; Hagoort, P.; Yang, Y.

    2008-01-01

    In an event-related potential experiment with Chinese discourses as material, we investigated how and when accentuation influences spoken discourse comprehension in relation to the different information states of the critical words. These words could either provide new or old information. It was

  19. Semantic ambiguity processing in sentence context: Evidence from event-related fMRI

    NARCIS (Netherlands)

    Zempleni, Monika-Zita; Renken, Remco; Hoeks, John C. J.; Hoogduin, Johannes M.; Stowe, Laurie A.

    2007-01-01

    Lexical semantic ambiguity is the phenomenon when a word has multiple meanings (e.g. 'bank'). The aim of this event-related functional MRI study was to identify those brain areas, which are involved in contextually driven ambiguity resolution. Ambiguous words were selected which have a most

  20. Pitch Processing in Tonal-Language-Speaking Children with Autism: An Event-Related Potential Study

    Science.gov (United States)

    Yu, Luodi; Fan, Yuebo; Deng, Zhizhou; Huang, Dan; Wang, Suiping; Zhang, Yang

    2015-01-01

    The present study investigated pitch processing in Mandarin-speaking children with autism using event-related potential measures. Two experiments were designed to test how acoustic, phonetic and semantic properties of the stimuli contributed to the neural responses for pitch change detection and involuntary attentional orienting. In comparison…

  1. Effects of stimulus repetitions on the event-related potential of humans and rats

    NARCIS (Netherlands)

    Sambeth, A.; Maes, J.H.R.; Quian Quiroga, R.; Coenen, A.M.L.

    2004-01-01

    The present study compared the effects of repeated stimulus presentations on the event-related potential (ERP) of humans and rats. Both species were presented with a total of 100 auditory stimuli, divided into four blocks of 25 stimuli. By means of wavelet denoising, single-trial ERPs were

  2. Developmental Changes in Memory Encoding: Insights from Event-Related Potentials

    Science.gov (United States)

    Rollins, Leslie; Riggins, Tracy

    2013-01-01

    The aim of the present study was to investigate developmental changes in encoding processes between 6-year-old children and adults using event-related potentials (ERPs). Although episodic memory ("EM") effects have been reported in both children and adults at retrieval and subsequent memory effects have been established in adults, no…

  3. Components of the event-related potential following degraded and undegraded visual stimuli.

    NARCIS (Netherlands)

    Kok, A.; de Looren de Jong, H.

    1980-01-01

    Event-related potentials were recorded in response to visual stimuli in 2 reaction tasks in which 12 right-handed male undergraduates were instructed to react immediately to the stimuli, or to delay their response for 2 sec. There were 4 types of stimuli: frequent-degraded, frequent-undegraded,

  4. The effects of cortisol administration on approach-avoidance behavior: An event-related potential study

    NARCIS (Netherlands)

    Peer, J.M. van; Roelofs, K.; Rotteveel, M.; Dijk, J.G. van; Spinhoven, P.; Ridderinkhof, K.R.

    2007-01-01

    We investigated the effects of cortisol administration (50 mg) on approach and avoidance tendencies in low and high trait avoidant healthy young men. Event-related brain potentials (ERPs) were measured during a reaction time task, in which participants evaluated the emotional expression of

  5. Early Processing of Emotional Faces in Children with Autism: An Event-Related Potential Study

    Science.gov (United States)

    Batty, Magali; Meaux, Emilie; Wittemeyer, Kerstin; Roge, Bernadette; Taylor, Margot J.

    2011-01-01

    Social deficits are one of the most striking manifestations of autism spectrum disorders (ASDs). Among these social deficits, the recognition and understanding of emotional facial expressions has been widely reported to be affected in ASDs. We investigated emotional face processing in children with and without autism using event-related potentials…

  6. An event-related brain potential correlate of visual short-term memory

    NARCIS (Netherlands)

    Klaver, Peter; Talsma, D.; Wijers, Albertus; Heinze, Hans-Jochen; Mulder, Gijsbertus

    1999-01-01

    EVENT-RELATED potentials (ERPs) were recorded as 12 subjects performed a delayed matching to sample task. We presented two bilateral abstract shapes and cued spatially which had to be memorized for a subsequent matching task: left, right or both. During memorization a posterior slow negative ERP

  7. Using visual advance information: an event-related functional MRI study.

    NARCIS (Netherlands)

    Klaver, P.; Fell, J.; Weis, S.; Greiff, A. de; Ruhlmann, J.; Reul, J.; Elger, C.E.; Fernandez, G.S.E.

    2004-01-01

    Our event-related functional MRI (efMRI) study investigates whether visual advance information (AI) affects rather perceptual or central response-related processing areas. Twelve subjects were required to make a go/no-go decision to a conjunction of a specific color and motion direction. The stimuli

  8. Genetics of the human electroencephalogram (EEG) and event-related brain potentials (ERPs): a review

    NARCIS (Netherlands)

    van Beijsterveldt, C.E.M.; Boomsma, D.I.

    1994-01-01

    Twin and family studies of normal variation in the human electroencephalogram (EEG) and event related potentials (ERPs) are reviewed. Most of these studies are characterized by small sample sizes. However, by summarizing these studies in one paper, we may be able to gain some insight into the

  9. Effects of sleep deprivation on event-related fields and alpha activity during rhythmic force production

    NARCIS (Netherlands)

    Boonstra, T.W.; Daffertshofer, A.; Beek, P.J.

    2005-01-01

    The influence of sleep deprivation (SD) on event-related fields and the distribution of power over the scalp of MEG imaged brain activity was studied during acoustically paced rhythmic force production. At the behavioral level, SD resulted in a reduction of the lag (negative asynchrony) between

  10. The Influence of Contour Fragmentation on Recognition Memory: An Event-Related Potential Study

    Science.gov (United States)

    Brodeur, Mathieu B.; Debruille, J. Bruno; Renoult, Louis; Prevost, Marie; Dionne-Dostie, Emmanuelle; Buchy, Lisa; Lepage, Martin

    2011-01-01

    The present study was carried out to examine how the event-related potentials to fragmentation predict recognition success. Stimuli were abstract meaningless figures that were either complete or fragmented to various extents but still recoverable. Stimuli were first encoded as part of a symmetry discrimination task. In a subsequent recognition…

  11. Genetic Correlation Between the P300 Event-Related Brain Potential and the EEG Power Spectrum

    NARCIS (Netherlands)

    Anokhin, A.P.; van Baal, G.C.M.; van Beijsterveldt, C.E.M.; de Geus, E.J.C.; Grant, J.; Boomsma, D.I.

    2001-01-01

    Previous studies have demonstrated moderate heritability of the P300 component of event-related brain potentials (ERPs) and high heritability of background electroencephalogram (EEG) power spectrum. However, it is unclear whether EEG and ERPs are influenced by common or independent genetic factors.

  12. Event-Related Potentials in Adolescents with Combined ADHD and CD Disorder: A Single Stimulus Paradigm

    Science.gov (United States)

    Du, Jing; Li, Jianming; Wang, Ying; Jiang, Qianjin; Livesley, W. John; Jang, Kerry L.; Wang, Kai; Wang, Wei

    2006-01-01

    Some studies of the event-related potentials demonstrated a reduction of the voluntary component P3 (P300 or P3b) in youngsters with the attention deficit/hyperactivity disorder (ADHD) or in conduct disorders (CD), and a reduction of the automatic processing component, mismatch negativity, in patients with both ADHD and CD (ADHD+CD). Recently, a…

  13. P300 event-related potential in euthymic patients with bipolar disorder.

    Science.gov (United States)

    Lahera, G; Pedrera, A; Cabañes, L; Fernandez-Lorente, J; Simal, P; Montes, J M; Saiz-Ruiz, J

    2009-02-01

    Auditory P300 event-related potential (ERP) and performance on Sustained Attention were evaluated in 24 euthymic bipolar patients and 38 healthy volunteers. There were no significant differences between groups, and performance in sustained attention had no significant influence in the P300 responses. P300 response might be driven by the presence of mood symptoms.

  14. Cognitive Brain Event-Related Potentials and Emotion Processing in Maltreated Children.

    Science.gov (United States)

    Pollak, Seth D.; Cicchetti, Dante; Klorman, Rafael; Brumaghim, Joan T.

    1997-01-01

    Recorded cognitive event-related potentials from maltreated and nonmaltreated children during presentations of happy, angry, or neutral facial expressions. Found that for nonmaltreated children, the average amplitude of P300 was comparable for responses to happy and neutral expressions. Maltreated children displayed larger P300 amplitude to…

  15. Impaired Phonological and Orthographic Word Representations among Adult Dyslexic Readers: Evidence from Event-Related Potentials

    Science.gov (United States)

    Meyler, Ann; Breznitz, Zvia

    2005-01-01

    The authors examined the processing of phonological and orthographic word representations among 17 dyslexic and 16 normal college-level readers using Event-Related Potential measures. They focused on 2 early components--the P200 and the P300. The results revealed P200 and P300 components of lower amplitude and later latency among dyslexic readers…

  16. Morphological Encoding in German Children's Language Production: Evidence from Event-Related Brain Potentials

    Science.gov (United States)

    Jessen, Anna; Fleischhauer, Elisabeth; Clahsen, Harald

    2017-01-01

    This study reports developmental changes in morphological encoding across late childhood. We examined event-related brain potentials (ERPs) during the silent production of regularly vs. irregularly inflected verb forms (viz. "-t" vs. "-n" participles of German) in groups of eight- to ten-year-olds, eleven- to…

  17. Temporal Dynamics of Late Second Language Acquisition: Evidence from Event-Related Brain Potentials

    Science.gov (United States)

    Steinhauer, Karsten; White, Erin J.; Drury, John E.

    2009-01-01

    The ways in which age of acquisition (AoA) may affect (morpho)syntax in second language acquisition (SLA) are discussed. We suggest that event-related brain potentials (ERPs) provide an appropriate online measure to test some such effects. ERP findings of the past decade are reviewed with a focus on recent and ongoing research. It is concluded…

  18. Hypoxia-inducible ERO1α promotes cancer progression through modulation of integrin-β1 modification and signalling in HCT116 colorectal cancer cells.

    Science.gov (United States)

    Takei, Norio; Yoneda, Akihiro; Sakai-Sawada, Kaori; Kosaka, Marina; Minomi, Kenjiro; Tamura, Yasuaki

    2017-08-24

    Endoplasmic reticulum disulphide oxidase 1α (ERO1α) is an oxidase localized in the endoplasmic reticulum that plays a role in the formation of disulphide bonds of secreted and cell-surface proteins. We previously showed that ERO1α is overexpressed in various types of cancer and we further identified ERO1α expression as a novel factor related to poor prognosis in cancer. However, the biological functions of ERO1α in cancer remain unclear. Here, we investigated the cell biological roles of ERO1α in the human colon-cancer cell line HCT116. ERO1α knockout (KO) by using CRISPR/Cas9 resulted in decreased tumourigenicity in vivo and reduced cell proliferation only under hypoxia in vitro, which suggested that ERO1α promotes cancer progression specifically in a low-oxygen environment. Thus, we evaluated the function of ERO1α in cell proliferation under hypoxia, and found that under hypoxic conditions, ERO1α KO resulted in a contact-inhibited morphology and diminished motility of cells. We further showed that ERO1α KO induced a change in integrin-β1 glycosylation and thus an attenuation of cell-surface integrin-β1 expression, which resulted in the aforementioned phenotype. Our study has established a previously unrecognized link between ERO1α expression and integrin activation, and thus provides new evidence for the effectiveness of ERO1α-targeted therapy for colorectal carcinoma.

  19. FEL Oscillators

    Energy Technology Data Exchange (ETDEWEB)

    George Neil

    2003-05-12

    FEL Oscillators have been around since 1977 providing not only a test bed for the physics of Free Electron Lasers and electron/photon interactions but as a workhorse of scientific research. More than 30 FEL oscillators are presently operating around the world spanning a wavelength range from the mm region to the ultraviolet using DC and rf linear accelerators and storage rings as electron sources. The characteristics that have driven the development of these sources are the desire for high peak and average power, high micropulse energies, wavelength tunability, timing flexibility, and wavelengths that are unavailable from more conventional laser sources. Substantial user programs have been performed using such sources encompassing medicine, biology, solid state research, atomic and molecular physics, effects of non-linear fields, surface science, polymer science, pulsed laser vapor deposition, to name just a few.

  20. Disulphide production by Ero1a-PDI relay is rapid and effectively regulated

    DEFF Research Database (Denmark)

    Appenzeller-Herzog, Christian; Riemer, Jan; Zito, Ester

    2010-01-01

    The molecular networks that control endoplasmic reticulum (ER) redox conditions in mammalian cells are incompletely understood. Here, we show that after reductive challenge the ER steady-state disulphide content is restored on a time scale of seconds. Both the oxidase Ero1a and the oxidoreductase...

  1. Näitus Eros külmade kiviseinte vahel / Marika Vernik

    Index Scriptorium Estoniae

    Vernik, Marika

    2001-01-01

    Tšehhi erootiliste ehete näitusest "Eros" Rakvere muuseumis, lähemalt Blanka Sperkova, Martin Pouzari, Lucie Krejcova, Barbora Kalisova, Jolana Sperkova, Blanka, Ctvrteckova, Jan Haseki, Karol Weisslechneri, Susan Ewingi, Jiri Jahelka ja Michal Novotny töödest

  2. Eros in the first century’s Christian theology. Pseudo-Dionysius the Areopagite

    Directory of Open Access Journals (Sweden)

    Mircea Adrian Marica

    2015-11-01

    Full Text Available For among most contemporaries, the concept of Eros seems to have nothing to do with Christianity. Sifting through the psychoanalysis of sexual fantasy, theologically it says nothing. Our study gives reasons showing that for theologians since the dawn of the Christian era, Eros-love plays a fundamental role.. The connotations of this concept, however, are different from those of today, when its sensory meaning is more restricted to sexuality. Greek theologians of the first centuries after Christ, taught the concept of Plato enshrined as a unifying enthusiasm, the attraction of inferior to superior states, as “hungry and thirsty” for something continuously higher, developing, and enriching the connotation. The work of Dionysius ((Pseudo Areopagite, the Idea of Good, leads us step by step up the ascent of the erotically chaste, and is identified with the One-God, who is the very source of love. Consequently, Eros-love originates from God, Eros- love being not only an ascending but firstly a descending love, which calls for a reciprocal communion.

  3. Distinct pattern of P3a event-related potential in borderline personality disorder.

    Science.gov (United States)

    Meares, Russell; Melkonian, Dmitriy; Gordon, Evian; Williams, Leanne

    2005-02-28

    P3a and P3b event-related brain potentials to auditory stimuli were recorded for 17 unmedicated patients with borderline personality disorder, 17 matched healthy controls and 100 healthy control participants spanning five decades. Using high-resolution fragmentary decomposition for single-trial event-related potential analysis, distinctive disturbances in P3a in borderline personality disorder patients were found: abnormally enhanced amplitude, failure to habituate and a loss of temporal locking with P3b. Normative age dependencies from 100 controls suggest that natural age-related decline in P3a amplitude is reduced in borderline personality disorder patients and is likely to indicate failure of frontal maturation. On the basis of the theories of Hughlings Jackson, this conceptualization of borderline personality disorder is consistent with an aetiological model of borderline personality disorder.

  4. Event-related potentials dissociate perceptual from response-related age effects in visual search

    DEFF Research Database (Denmark)

    Wiegand, Iris; Müller, Hermann J.; Finke, Kathrin

    2013-01-01

    measures with lateralized event-related potentials of younger and older adults performing a compound-search task, in which the target-defining dimension of a pop-out target (color/shape) and the response-critical target feature (vertical/horizontal stripes) varied independently across trials. Slower......Attentional decline plays a major role in cognitive changes with aging. However, which specific aspects of attention contribute to this decline is as yet little understood. To identify the contributions of various potential sources of age decrements in visual search, we combined response time...... responses in older participants were associated with age differences in all analyzed event-related potentials from perception to response, indicating that behavioral slowing originates from multiple stages within the information-processing stream. Furthermore, analyses of carry-over effects from one trial...

  5. Learning of musical and linguistic structures: comparing event-related potentials and behavior.

    Science.gov (United States)

    Francois, Clément; Schön, Daniele

    2010-10-06

    To learn a new language, it is necessary for the learner to succeed in segmenting the continuous stream of sounds into significant units. Previous behavioral studies have shown that it is possible to segment a language or musical stream based only on probabilities of occurrence between adjacent syllables/tones. Here we used a sung language and tested participants' learning of both linguistic and musical structures while recording electroencephalography. Although behavioral results showed learning of the linguistic structure only, event-related potential results for both dimensions showed a negative component sensitive to the degree of familiarity of items. We discuss this component as an index of lexical search, also pointing to the greater sensitivity of the event-related potentials compared to the behavioral responses.

  6. The Recording and Quantification of Event-Related Potentials: II. Signal Processing and Analysis

    Directory of Open Access Journals (Sweden)

    Paniz Tavakoli

    2015-06-01

    Full Text Available Event-related potentials are an informative method for measuring the extent of information processing in the brain. The voltage deflections in an ERP waveform reflect the processing of sensory information as well as higher-level processing that involves selective attention, memory, semantic comprehension, and other types of cognitive activity. ERPs provide a non-invasive method of studying, with exceptional temporal resolution, cognitive processes in the human brain. ERPs are extracted from scalp-recorded electroencephalography by a series of signal processing steps. The present tutorial will highlight several of the analysis techniques required to obtain event-related potentials. Some methodological issues that may be encountered will also be discussed.

  7. Expression of physiological sensation of anatomical patterns in wood: An event-related brain potential study

    OpenAIRE

    Sha Sha Song; Guang Jie Zhao

    2012-01-01

    The emotional and psychological activities associated with the visual perception of macroscopic and microscopic structure patterns of wood were investigated. The macroscopic and microscopic structure patterns of 18 different timber tree species of northeast China were selected as the research objects, and these were divided into eight categories for event-related potential analysis. The 30 effective subjects’ tasks were to watch the wood structure stimuli patterns and evaluate them on a 7-poi...

  8. MEG event-related desynchronization and synchronization deficits during basic somatosensory processing in individuals with ADHD

    Directory of Open Access Journals (Sweden)

    Wang Frank

    2008-02-01

    Full Text Available Abstract Background Attention-Deficit/Hyperactivity Disorder (ADHD is a prevalent, complex disorder which is characterized by symptoms of inattention, hyperactivity, and impulsivity. Convergent evidence from neurobiological studies of ADHD identifies dysfunction in fronto-striatal-cerebellar circuitry as the source of behavioural deficits. Recent studies have shown that regions governing basic sensory processing, such as the somatosensory cortex, show abnormalities in those with ADHD suggesting that these processes may also be compromised. Methods We used event-related magnetoencephalography (MEG to examine patterns of cortical rhythms in the primary (SI and secondary (SII somatosensory cortices in response to median nerve stimulation, in 9 adults with ADHD and 10 healthy controls. Stimuli were brief (0.2 ms non-painful electrical pulses presented to the median nerve in two counterbalanced conditions: unpredictable and predictable stimulus presentation. We measured changes in strength, synchronicity, and frequency of cortical rhythms. Results Healthy comparison group showed strong event-related desynchrony and synchrony in SI and SII. By contrast, those with ADHD showed significantly weaker event-related desynchrony and event-related synchrony in the alpha (8–12 Hz and beta (15–30 Hz bands, respectively. This was most striking during random presentation of median nerve stimulation. Adults with ADHD showed significantly shorter duration of beta rebound in both SI and SII except for when the onset of the stimulus event could be predicted. In this case, the rhythmicity of SI (but not SII in the ADHD group did not differ from that of controls. Conclusion Our findings suggest that somatosensory processing is altered in individuals with ADHD. MEG constitutes a promising approach to profiling patterns of neural activity during the processing of sensory input (e.g., detection of a tactile stimulus, stimulus predictability and facilitating our

  9. Relationship between early and late stages of information processing: an event-related potential study

    OpenAIRE

    Claudio Portella; Sergio Machado; Oscar Arias-Carrión; Sack, Alexander T.; Julio Guilherme Silva; Marco Orsini; Marco Antonio Araujo Leite; Adriana Cardoso Silva; Nardi, Antonio E.; Mauricio Cagy; Roberto Piedade; Pedro Ribeiro

    2012-01-01

    The brain is capable of elaborating and executing different stages of information processing. However, exactly how these stages are processed in the brain remains largely unknown. This study aimed to analyze the possible correlation between early and late stages of information processing by assessing the latency to, and amplitude of, early and late event-related potential (ERP) components, including P200, N200, premotor potential (PMP) and P300, in healthy participants in the context of a vis...

  10. Inverse Effectiveness and Multisensory Interactions in Visual Event-Related Potentials with Audiovisual Speech

    OpenAIRE

    Stevenson, Ryan A.; Bushmakin, Maxim; Kim, Sunah; Wallace, Mark T.; Puce, Aina; James, Thomas W

    2012-01-01

    In recent years, it has become evident that neural responses previously considered to be unisensory can be modulated by sensory input from other modalities. In this regard, visual neural activity elicited to viewing a face is strongly influenced by concurrent incoming auditory information, particularly speech. Here, we applied an additive-factors paradigm aimed at quantifying the impact that auditory speech has on visual event-related potentials (ERPs) elicited to visual speech. These multise...

  11. Cortical Neural Synchronization Underlies Primary Visual Consciousness of Qualia: Evidence from Event-Related Potentials

    OpenAIRE

    Babiloni, Claudio; Marzano, Nicola; Soricelli, Andrea; Cordone, Susanna; Millán-Calenti, José Carlos; Del Percio, Claudio; Buján, Ana

    2016-01-01

    This article reviews three experiments on event-related potentials (ERPs) testing the hypothesis that primary visual consciousness (stimulus self-report) is related to enhanced cortical neural synchronization as a function of stimulus features. ERP peak latency and sources were compared between “seen” trials and “not seen” trials, respectively related and unrelated to the primary visual consciousness. Three salient features of visual stimuli were considered (visuospatial, emotional face expre...

  12. The Recording and Quantification of Event-Related Potentials: II. Signal Processing and Analysis

    OpenAIRE

    Paniz Tavakoli; Ken Campbell

    2015-01-01

    Event-related potentials are an informative method for measuring the extent of information processing in the brain. The voltage deflections in an ERP waveform reflect the processing of sensory information as well as higher-level processing that involves selective attention, memory, semantic comprehension, and other types of cognitive activity. ERPs provide a non-invasive method of studying, with exceptional temporal resolution, cognitive processes in the human brain. ERPs are extracted from s...

  13. Event-related brain potentials as indices of mental workload and attentional allocation

    Science.gov (United States)

    Kramer, Arthur F.; Donchin, Emanuel; Wickens, Christopher D.

    1988-01-01

    Over the past decade considerable strides were made in explicating the antecedant conditions necessary for the elicitation, and the modulation of the amplitude and latency, of a number of components of the event-related brain potential (ERP). The focus of this report is on P300. The degree to which the psychophysiological measures contribute to issues in two real-world domains (communication devices for the motor impaired and the assessment of mental workload of aircraft pilots) are examined.

  14. The Event-related Potential P300 in Patients with Migraine

    OpenAIRE

    Titlic, Marina; Mise, Nikolina Ivica; Pintaric, Irena; Rogosic, Veljko; Vanjaka-Rogosic, Lucija; Mihalj, Mario; Jurinovic, Pavao; Katic, Ana Curkovic;; Andjelinovic, Maja

    2015-01-01

    Objective: Recording of event-related potentials by using oddball paradigm of auditory P300 has yielded conflicting results in migraine. The aim of this study was to demonstrate that migraine patients have reduced P300 amplitude and prolonged P300 latency, suggesting alterations of the cognitive-evaluative component. Methods: We recruited 29 migraine patients (24 females; median age 40 years) and 29 healthy age- and gender-matched participants. Participants were subjected to the same testing ...

  15. Memory and event-related potentials for rapidly presented emotional pictures

    OpenAIRE

    Versace, Francesco; Bradley, Margaret M.; Lang, Peter J.

    2010-01-01

    Dense array event-related potentials (ERPs) and memory performance were assessed following rapid serial visual presentation (RSVP) of emotional and neutral pictures. Despite the extremely brief presentation, emotionally arousing pictures prompted an enhanced negative voltage over occipital sensors, compared to neutral pictures, replicating previous encoding effects. Emotionally arousing pictures were also remembered better in a subsequent recognition test, with higher hit rates and better dis...

  16. Abnormal occipital event-related potentials in Parkinson's disease with concomitant REM sleep behavior disorder.

    Science.gov (United States)

    Gaudreault, Pierre-Olivier; Gagnon, Jean-François; Montplaisir, Jacques; Vendette, Mélanie; Postuma, Ronald B; Gagnon, Katia; Gosselin, Nadia

    2013-02-01

    Rapid eye movement sleep behavior disorder is found in 33-46% of patients with Parkinson's disease and was shown to be associated with cognitive deficits. Our goal was to improve our understanding of the role of this sleep disorder in cerebral dysfunction occurring in Parkinson's disease using a visual cognitive task and event-related potentials. Sixteen patients with Parkinson's disease and rapid eye movement sleep behavior disorder, 15 patients with Parkinson's disease without rapid eye movement sleep behavior disorder and 16 healthy control subjects were included. The amplitude and latency of event-related potentials were compared between groups. No group differences were found for reaction times or accuracy. A Group effect was found for P2 wave amplitude; patients with rapid eye movement sleep behavior disorder had increased P2 in comparison with the control group (p disorder were associated with abnormal visual P2 component of event-related potentials. Although patients with Parkinson's disease alone were not significantly different from patients with combined Parkinson's disease and rapid eye movement sleep behavior disorder, their P2 amplitudes were not sufficiently abnormal to differ from that of control subjects. This study confirms that rapid eye movement sleep behavior disorder accentuates cerebral dysfunctions in Parkinson's disease. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Changes in event-related potentials in patients with first-episode schizophrenia and their siblings.

    Science.gov (United States)

    Yang, Chengqing; Zhang, Tianhong; Li, Zezhi; Heeramun-Aubeeluck, Anisha; Liu, Na; Huang, Nan; Zhang, Jie; He, Leiying; Li, Hui; Tang, Yingying; Chen, Fazhan; Wang, Jijun; Lu, Zheng

    2017-01-17

    This study aimed to explore the characteristics of event-related potentials induced by facial emotion recognition in patients with first-episode schizophrenia and in their siblings. In this case-control study, 30 first-episode schizophrenia patients, 26 siblings, and 30 healthy controls were enrolled. They completed facial emotion recognition tasks from the Ekman Standard Faces Database as an induction for evoked potentials. Evoked potential data were obtained using a 64-channel electroencephalography system. Average evoked potential waveforms were computed from epochs for each stimulus type. The amplitudes and latency of the event-related potentials for P100 (positive potential 100 ms after stimulus onset), N170 (negative potential 170 ms after stimulus onset), and N250 (fronto-central peak) were investigated at O1, O2, P7, and P8 electrode locations. There were significant differences between the groups for P100 amplitude (F = 11.526, P schizophrenia group at the O1, O2, P7, and P8 electrode positions. There were no significant differences between the siblings of schizophrenia patients and the healthy controls. Patients with schizophrenia showed abnormalities in P100 amplitude, but similar results were not observed in their siblings. These results provide evidence of dysfunctional event-related potential patterns underlying facial emotion processing in patients with schizophrenia. P100 may be a characteristic index of schizophrenia.

  18. Simultaneous functional near-infrared brain imaging and event-related potential studies of Stroop effect

    Science.gov (United States)

    Zhai, Jiahuan; Li, Ting; Zhang, Zhongxing; Gong, Hui

    2009-02-01

    Functional near-infrared brain imaging (fNIRI) and event-related potential (ERP) were used simultaneous to detect the prefrontal cortex (PFC) which is considered to execute cognitive control of the subjects while performing the Chinese characters color-word matching Stroop task with event-related design. The fNIRI instrument is a portable system operating at three wavelengths (735nm & 805nm &850nm) with continuous-wave. The event-related potentials were acquired by Neuroscan system. The locations of optodes corresponding to the electrodes were defined four areas symmetrically. In nine native Chinese-speaking fit volunteers, fNIRI measured the hemodynamic parameters (involving oxy-/deoxy- hemoglobin) changes when the characteristic waveforms (N500/P600) were recorded by ERP. The interference effect was obvious as a longer reaction time for incongruent than congruent and neutral stimulus. The responses of hemodynamic and electrophysiology were also stronger during incongruent compared to congruent and neutral trials, and these results are similar to those obtained with fNIRI or ERP separately. There are high correlations, even linear relationship, in the two kinds of signals. In conclusion, the multi-modality approach combining of fNIRI and ERP is feasible and could obtain more cognitive function information with hemodynamic and electrophysiology signals. It also provides a perspective to prove the neurovascular coupling mechanism.

  19. Evaluation of cognitive disorders in multiple sclerosis patients by auditory event related potential

    Directory of Open Access Journals (Sweden)

    Parisa Rasoulifard

    2012-12-01

    Full Text Available Bachground and Aim: The involvement of central auditory nervous system is relatively prevalent in patients suffering from multiple sclerosis (MS. To understand cortex function and to investigate cognitive impairment, event related potential is considered as a valuable tool. This study was aimed to compare the amplitude and latency of the event related potentials of P300 in MS patients and normal individuals.Methods: This cross sectional study was conducted on 21 MS patients and 27 normal cases aged 18-50 years. Auditory P300 was recorded with oddball paradigm, using two tone burst stimuli (1000 and 2000.Results: In MS patients, mean latencies were significantly longer (p<0.001 and mean amplitude were significantly lower (p<0.001, in both males and females. Sex did not affect P300 latencies and amplitudes significantly.Conclusion: MS patients show some degree of event related potential abnormalities. Combination of auditory P300 and neuropsychological tests may be useful to investigate cognitive impairment in MS patients.

  20. U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center-fiscal year 2010 annual report

    Science.gov (United States)

    Nelson, Janice S.

    2011-01-01

    The Earth Resources Observation and Science (EROS) Center is a U.S. Geological Survey (USGS) facility focused on providing science and imagery to better understand our Earth. The work of the Center is shaped by the earth sciences, the missions of our stakeholders, and implemented through strong program and project management, and application of state-of-the-art information technologies. Fundamentally, EROS contributes to the understanding of a changing Earth through 'research to operations' activities that include developing, implementing, and operating remote-sensing-based terrestrial monitoring capabilities needed to address interdisciplinary science and applications objectives at all levels-both nationally and internationally. The Center's programs and projects continually strive to meet, and where possible exceed, the changing needs of the USGS, the Department of the Interior, our Nation, and international constituents. The Center's multidisciplinary staff uses their unique expertise in remote sensing science and technologies to conduct basic and applied research, data acquisition, systems engineering, information access and management, and archive preservation to address the Nation's most critical needs. Of particular note is the role of EROS as the primary provider of Landsat data, the longest comprehensive global land Earth observation record ever collected. This report is intended to provide an overview of the scientific and engineering achievements and illustrate the range and scope of the activities and accomplishments at EROS throughout fiscal year (FY) 2010. Additional information concerning the scientific, engineering, and operational achievements can be obtained from the scientific papers and other documents published by EROS staff or by visiting our web site at http://eros.usgs.gov. We welcome comments and follow-up questions on any aspect of this Annual Report and invite any of our customers or partners to contact us at their convenience. To

  1. Oscillators and Eigenvalues

    DEFF Research Database (Denmark)

    Lindberg, Erik

    1997-01-01

    In order to obtain insight in the nature of nonlinear oscillators the eigenvalues of the linearized Jacobian of the differential equations describing the oscillator are found and displayed as functions of time. A number of oscillators are studied including Dewey's oscillator (piecewise linear wit...... with negative resistance), Kennedy's Colpitts-oscillator (with and without chaos) and a new 4'th order oscillator with hyper-chaos.......In order to obtain insight in the nature of nonlinear oscillators the eigenvalues of the linearized Jacobian of the differential equations describing the oscillator are found and displayed as functions of time. A number of oscillators are studied including Dewey's oscillator (piecewise linear...

  2. Oscillator circuits

    CERN Document Server

    Graf, Rudolf F

    1996-01-01

    This series of circuits provides designers with a quick source for oscillator circuits. Why waste time paging through huge encyclopedias when you can choose the topic you need and select any of the specialized circuits sorted by application?This book in the series has 250-300 practical, ready-to-use circuit designs, with schematics and brief explanations of circuit operation. The original source for each circuit is listed in an appendix, making it easy to obtain additional information.Ready-to-use circuits.Grouped by application for easy look-up.Circuit source listing

  3. Power oscillation damping controller

    DEFF Research Database (Denmark)

    2012-01-01

    A power oscillation damping controller is provided for a power generation device such as a wind turbine device. The power oscillation damping controller receives an oscillation indicating signal indicative of a power oscillation in an electricity network and provides an oscillation damping control...... signal in response to the oscillation indicating signal, by processing the oscillation damping control signal in a signal processing chain. The signal processing chain includes a filter configured for passing only signals within a predetermined frequency range....

  4. Event-related theta synchronization predicts deficit in facial affect recognition in schizophrenia.

    Science.gov (United States)

    Csukly, Gábor; Stefanics, Gábor; Komlósi, Sarolta; Czigler, István; Czobor, Pál

    2014-02-01

    Growing evidence suggests that abnormalities in the synchronized oscillatory activity of neurons in schizophrenia may lead to impaired neural activation and temporal coding and thus lead to neurocognitive dysfunctions, such as deficits in facial affect recognition. To gain an insight into the neurobiological processes linked to facial affect recognition, we investigated both induced and evoked oscillatory activity by calculating the Event Related Spectral Perturbation (ERSP) and the Inter Trial Coherence (ITC) during facial affect recognition. Fearful and neutral faces as well as nonface patches were presented to 24 patients with schizophrenia and 24 matched healthy controls while EEG was recorded. The participants' task was to recognize facial expressions. Because previous findings with healthy controls showed that facial feature decoding was associated primarily with oscillatory activity in the theta band, we analyzed ERSP and ITC in this frequency band in the time interval of 140-200 ms, which corresponds to the N170 component. Event-related theta activity and phase-locking to facial expressions, but not to nonface patches, predicted emotion recognition performance in both controls and patients. Event-related changes in theta amplitude and phase-locking were found to be significantly weaker in patients compared with healthy controls, which is in line with previous investigations showing decreased neural synchronization in the low frequency bands in patients with schizophrenia. Neural synchrony is thought to underlie distributed information processing. Our results indicate a less effective functioning in the recognition process of facial features, which may contribute to a less effective social cognition in schizophrenia. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  5. An event-related analysis of P300 by simultaneous EEG/fMRI

    Science.gov (United States)

    Wang, Li-qun; Wang, Mingshi; Mizuhara, Hiroaki

    2006-09-01

    In this study, P300 that induced by visual stimuli was examined with simultaneous EEG/fMRI. For the purpose of combine the best temporary resolution with the best special resolution together to estimate the brain function, event-related analysis contributed to this methodological trial. A 64 channel MRT-compatible MR EEG amplifier (BrainAmp: made of Brain Production GmbH, Gennany) was used in the measurement simultaneously with fMRI scanning. The reference channel is between Fz, Cz and Pz. Sampling rate of raw EEG was 5 kHz, and the MRT noise reduction was performed. EEG recording synchronized with MRI scan by our original stimulus system, and an oddball paradigm (four-oriented Landolt Ring presentation) was performed in the official manner. After P300 segmentation, the timing of P300 was exported to event-related analysis of fMRI data with SPM99 software. In single subject study, the significant activations appear in the left superior frontal, Broca's area and on both sides of the parietal lobule when P300 occurred. It is suggest that P300 may be an integration carried out by top-down signal from frontal to the parietal lobule, which regulates an Attention-Logical Judgment process. Compared with other current methods, the event related analysis by simultaneous EEG/IMRI is excellent in the point that can describe the cognitive process with reality unifying further temporary and spatial information. It is expected that examination and demonstration of the obtained result will supply with the promotion of this powerful methods.

  6. Bulk Compositional Trends in Meteorites: A Guide for Analysis and Interpretation of NEAR XGRS Data from Asteroid 433 Eros

    Science.gov (United States)

    Nittler, L. R.; Clark, P. E.; McCoy, T. J.; Murphy, M. E.; Trombka, J. I.

    2000-01-01

    We have compiled a large database of bulk meteorite elemental compositions. We investigate compositional trends in a variety of meteorite classes to aid in interpretation of NEAR XGRS elemental abundance data from the asteroid Eros.

  7. Is Asteroid 433 Eros Compositionally Homogeneous? New Analyses of NEAR-Shoemaker X-Ray Spectrometer Data

    Science.gov (United States)

    Nittler, L. R.; Trombka, J. I.

    2001-01-01

    We present new analysis techniques for NEAR-Shomaker X-ray spectrometer data to infer the compositional heterogeneity of asteroid 433 Eros. Preliminary results indicate a largely chondritic, homogeneous composition. Additional information is contained in the original extended abstract.

  8. Auditory event-related responses to diphthongs in different attention conditions

    DEFF Research Database (Denmark)

    Morris, David Jackson; Steinmetzger, Kurt; Tøndering, John

    2016-01-01

    The modulation of auditory event-related potentials (ERP) by attention generally results in larger amplitudes when stimuli are attended. We measured the P1-N1-P2 acoustic change complex elicited with synthetic overt (second formant, F2 = 1000 Hz) and subtle (F2 = 100 Hz) diphthongs, while subjects....... Multivariate analysis of ERP components from the rising F2 changes showed main effects of attention on P2 amplitude and latency, and N1-P2 amplitude. P2 amplitude decreased by 40% between the attend and ignore conditions, and by 60% between the attend and divert conditions. The effect of diphthong magnitude...

  9. The light-makeup advantage in facial processing: Evidence from event-related potentials

    OpenAIRE

    Tagai, Keiko; Shimakura, Hitomi; Isobe, Hiroko; Nittono, Hiroshi

    2017-01-01

    The effects of makeup on attractiveness have been evaluated using mainly subjective measures. In this study, event-related brain potentials (ERPs) were recorded from a total of 45 Japanese women (n = 23 and n = 22 for Experiment 1 and 2, respectively) to examine the neural processing of faces with no makeup, light makeup, and heavy makeup. To have the participants look at each face carefully, an identity judgement task was used: they were asked to judge whether the two faces presented in succ...

  10. Stereotype activation is unintentional: Behavioural and event-related potenials evidence.

    Science.gov (United States)

    Wang, Pei; Yang, Ya-Ping; Tan, Chen-Hao; Zhao, Xiang-Xia; Liu, Yong-He; Lin, Chong-De

    2016-04-01

    In this study, a priming Stroop paradigm was used to determine whether stereotype activation is unintentional. Priming conditions (priming/no-priming) and the relationship between priming and target (consistent/inconsistent/no-relation) were the independent variables; accuracy, reaction time and N400 amplitude were used as dependent variables. The reaction time revealed that stereotype activation is, to some extent, unintentional. Furthermore, the event-related potenial (ERP) results showed that N400 amplitude was larger for inconsistent conditions than for consistent conditions. This result supported the notion that stereotype activation is an unintentional and automatic process. © 2015 International Union of Psychological Science.

  11. Incorporating and integrating cognitive event-related potentials in the management of psychiatric disorders

    Directory of Open Access Journals (Sweden)

    Bragazzi NL

    2014-01-01

    Full Text Available Nicola Luigi Bragazzi,1,2 Giovanni Del Puente21School of Public Health, Department of Health Sciences (DISSAL, University of Genoa, Genoa, Italy; 2DINOGMI, Department of Neuroscience, Rehabilitation, Ophtalmology, Genetics, Maternal and Child Health, Section of Psychiatry, University of Genoa, Genoa, Italy Dr Salvatore Campanella has recently advocated the urgent need to incorporate cognitive event-related potentials (ERPs for a proper diagnosis, treatment, and prognosis of psychiatric disorders, on the basis of four working hypotheses, which are theoretically solid and experimentally supported.1View original paper by Campanella S.

  12. Pharmacodynamic Modelling of Placebo and Buprenorphine Effects on Event-Related Potentials in Experimental Pain

    DEFF Research Database (Denmark)

    Juul, Rasmus V; Foster, David J R; Upton, Richard N

    2014-01-01

    The purpose of the study was to investigate placebo and buprenorphine effects on event-related potentials (ERPs) in experimental pain and the potential benefit of population pharmacodynamic modelling in data analysis. Nineteen healthy volunteers received transdermal placebo and buprenorphine......-effects modelling implemented in NONMEM (V7.2.0.). Pharmacodynamic models were developed to adequately describe both placebo and buprenorphine ERP data. Models predicted significant placebo effects, but did not predict significant effects related to buprenorphine concentration. Models revealed that ERPs varied both...

  13. A bibliography of research conducted by the Earth Resources Observation Systems (EROS) Office, U.S. Geological Survey : 1975-1982

    Science.gov (United States)

    Bowman, Helen L.

    1984-01-01

    The U.S. Geological Survey's Earth Resources Observation Systems (EROS) Program was established in 1967 by Secretarial order to plan and develop techniques for collecting and analyzing remotely sensed data, and to apply these techniques to the resource inventory and management responsibilities of the Department of the Interior. U.S. Geological Survey scientists, realizing the potential benefits of synoptic views of the Earth, were among the first members of America's scientific community to press for the launch of civilian Earth-surface observation satellites. Under the leadership of Director William T. Pecora, U.S. Geological Survey initiatives greatly influenced the National Aeronautics and Space Administration's (NASA) development of the Landsat program.As part of the Landsat program, an agreement between NASA and the Geological Survey was signed to provide Landsat archiving and data production capabilities at the EROS Data Center in Sioux Falls, South Dakota. This partnership with NASA began in 1972 and continued until Presidential Directive 54 designated the National Oceanic and Atmospheric Administration (NOAA) of the Department of Commerce as the manager of U.S. civil operational land remote-sensing activities. NOAA has managed the Landsat program since Fiscal Year 1983, and EROS continues to process, archive, reproduce, and distribute Landsat data under a Memorandum of Understanding between NOAA and the Geological Survey. Archives at the EROS Data Center include over 2 million worldwide Landsat scenes and over 5 million aerial photographs, primarily of U.S. sites. Since the launch of Landsat 1, global imaging of the Earth's surface has become an operational tool for resource exploration and land management. As technology evolved, so did the EROS Program mission. Research and applications efforts began at the EROS Headquarters Office in the Washington metropolitan area in 1966; at the EROS Data Center in 1971; and at the EROS Field Office in Anchorage

  14. Erosões nas estruturas de concreto das galerias de aguas pluviais urbanas

    OpenAIRE

    Aguiar,J. E. de; Baptista,M. B.

    2011-01-01

    Este trabalho apresenta as conseqüências do surgimento das erosões no interior das estruturas de concreto das galerias de águas pluviais urbanas, com base em inspeções feita em mais de 180 km na rede de drenagem da cidade de Belo Horizonte (Brasil). O artigo descreve a gênese das erosões que po­dem ser por abrasão, por cavitação e por ataque químico, mostrando os processos de formação e evolução das patologias, chamando a atenção que elas podem levar as estruturas ao colapso. São apresentados...

  15. Caos, Gea y Eros. Desde el desorden a la armonía de la Paz

    Directory of Open Access Journals (Sweden)

    Francisco A. Muñoz

    2009-01-01

    Full Text Available La cosmogonía griega antigua, al igual que muchas otras, sitúa a Caos como el origen primigenio del Universo. Desde el inicio de los tiempos es acompañada (es femenino por Gea (la Tierra y Eros (el Amor. Con esta explicación se consigue incardinar el Universo, la Tierra, la naturaleza, la vida y los seres humanos con los dioses y las fuerzas sobrenaturales. Eros representaba el deseo que trae la vida, preocupado por conseguir las mejores condiciones para satisfacer las necesidades y procurar el desarrollo de las potencialidades humanas. Desde el comienzo de la historia, para que existiera armonía y paz era necesario gestionar el caos, la complejidad y la conflictividad, y buscar los equilibrios más justos y duraderos posibles.

  16. Contribuyendo al bienestar emocional de los compañeros: evaluación del Programa Compañeros Ayudantes en un instituto madrileño

    Directory of Open Access Journals (Sweden)

    Cristina del Barrio

    2011-06-01

    Full Text Available Un proyecto internacional desarrollado entre noviembre de 2007 y julio de 2009 se propuso implantar y evaluar un sistema de ayuda entre iguales en un centro de secundaria de Inglaterra, Italia y España, como medio de mejora de la convivencia. Los sistemas de ayuda entre iguales implican típicamente seleccionar a algunos estudiantes y entrenarlos para ayudar a sus compañeros. Mediante un diseño de grupo control con dos grupos, se formó a los ayudantes para poner en marcha un servicio de ayuda entre compañeros en los centros objeto de la intervención. Se presentan los resultados españoles de los cuestionarios de evaluación del programa, en la que participaron 248 estudiantes implicados en el programa y posibles usuarios del mismo, y 35 profesores, implicados y no implicados en el programa. Los resultados señalan que el programa es positivamente evaluado, apoyando su continuación profesores y alumnos, que coinciden en señalar las consecuencias positivas para víctimas y alumnos ayudantes, y en considerarlo un recurso para mejorar la convivencia en el centro.

  17. The geography and human cultural resources working group of the EROS program

    Science.gov (United States)

    Gerlach, A. C.

    1972-01-01

    The functions, activities, and objectives of the Geography and Human-Cultural Resources Working Group of the EROS program are outlined. The Group's primary function is to coordinate remote sensing experiments of physical scientists and the needs of socioeconomic and culturally orientated planners, policy makers, administrators, and other user groups. Other functions of the Group include land use analysis, resource mapping, and development of an operational automatic information system receptive to land use and environmental data.

  18. Tactile event-related potentials in amyotrophic lateral sclerosis (ALS): Implications for brain-computer interface.

    Science.gov (United States)

    Silvoni, S; Konicar, L; Prats-Sedano, M A; Garcia-Cossio, E; Genna, C; Volpato, C; Cavinato, M; Paggiaro, A; Veser, S; De Massari, D; Birbaumer, N

    2016-01-01

    We investigated neurophysiological brain responses elicited by a tactile event-related potential paradigm in a sample of ALS patients. Underlying cognitive processes and neurophysiological signatures for brain-computer interface (BCI) are addressed. We stimulated the palm of the hand in a group of fourteen ALS patients and a control group of ten healthy participants and recorded electroencephalographic signals in eyes-closed condition. Target and non-target brain responses were analyzed and classified offline. Classification errors served as the basis for neurophysiological brain response sub-grouping. A combined behavioral and quantitative neurophysiological analysis of sub-grouped data showed neither significant between-group differences, nor significant correlations between classification performance and the ALS patients' clinical state. Taking sequential effects of stimuli presentation into account, analyses revealed mean classification errors of 19.4% and 24.3% in healthy participants and ALS patients respectively. Neurophysiological correlates of tactile stimuli presentation are not altered by ALS. Tactile event-related potentials can be used to monitor attention level and task performance in ALS and may constitute a viable basis for future BCIs. Implications for brain-computer interface implementation of the proposed method for patients in critical conditions, such as the late stage of ALS and the (completely) locked-in state, are discussed. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  19. Event-Related Functional Magnetic Resonance Images during the Perception of Phantom Limb. A Brushing Task.

    Science.gov (United States)

    Pasaye, E H; Gutiérrez, R A; Alcauter, S; Mercadillo, R E; Aguilar-Castañeda, E; De Iturbe, M; Romero-Romo, J; Barrios, F A

    2010-12-01

    The phantom limb phenomenon has been used in amputee patients as a paradigm to study plasticity, mainly of the sensorimotor cortex. Nevertheless, most functional studies have been done in upper limb amputee patients using magnetoencephalography and functional magnetic resonance image imaging (fMRI). In addition, the actual experience of phantom limb sensation has not been widely used to study the neural mechanism of the human brain as a conscious knowledge of the phantom limb perception like the integration of the body image in amputee patients. fMRI studies of patients with lower limb amputation have recently been published, but none of these used an event-related design to try to observe only the stimulus application, correlating images with the subject's indication of phantom perception and discarding images with no phantom perception. In this work, we used the event-related fMRI design in two right-handed patients with identical right, transfemoral amputations, performing the same sensitive stimulation in a 3.0 T MR scanner. For comparison, we applied the same paradigm to six control subjects to compare the resulting functional maps. We found areas with statistical significance in the sensorimotor cortex contralateral to the site of stimulation, in the parietal lobe in Brodmann areas 3 in both cases (Patients and Control Subjects), but we also found activation in the Brodmann areas 6, 40, and 5 with stimulation of the stump. We observed a specific activation of the frontoparietal circuit during phantom limb perception in both amputee patients.

  20. Effects of white noise on event-related potentials in somatosensory Go/No-go paradigms.

    Science.gov (United States)

    Ohbayashi, Wakana; Kakigi, Ryusuke; Nakata, Hiroki

    2017-09-06

    Exposure to auditory white noise has been shown to facilitate human cognitive function. This phenomenon is termed stochastic resonance, and a moderate amount of auditory noise has been suggested to benefit individuals in hypodopaminergic states. The present study investigated the effects of white noise on the N140 and P300 components of event-related potentials in somatosensory Go/No-go paradigms. A Go or No-go stimulus was presented to the second or fifth digit of the left hand, respectively, at the same probability. Participants performed somatosensory Go/No-go paradigms while hearing three different white noise levels (45, 55, and 65 dB conditions). The peak amplitudes of Go-P300 and No-go-P300 in ERP waveforms were significantly larger under 55 dB than 45 and 65 dB conditions. White noise did not affect the peak latency of N140 or P300, or the peak amplitude of N140. Behavioral data for the reaction time, SD of reaction time, and error rates showed the absence of an effect by white noise. This is the first event-related potential study to show that exposure to auditory white noise at 55 dB enhanced the amplitude of P300 during Go/No-go paradigms, reflecting changes in the neural activation of response execution and inhibition processing.

  1. Influence of negative emotion on the framing effect: evidence from event-related potentials.

    Science.gov (United States)

    Ma, Qingguo; Pei, Guanxiong; Wang, Kai

    2015-04-15

    The framing effect is the phenomenon in which different descriptions of an identical problem can result in different choices. The influence of negative emotions on the framing effect and its neurocognitive basis are important issues, especially in the domain of saving lives, which is essential and highly risky. In each trial of our experiment, the emotion stimulus is presented to the participants, followed by the decision-making stimulus, which comprises certain and risky options with the same expected value. Each pair of options is positively or negatively framed. The behavioral results indicate a significant interactive effect between negative emotion and frame; thus, the risk preference under the positive frame can be enhanced by negative emotions, whereas this finding is not true under the negative frame. The event-related potential analysis indicates that choosing certain options under the positive frame with negative emotion priming generates smaller P2 and P3 amplitudes and a larger N2 amplitude than with neutral emotion priming. The event-related potential findings indicate that individuals can detect risk faster and experience more conflict and increased decision difficulty if they choose certain options under the positive frame with negative priming compared with neutral priming.

  2. Event-related potential P2 correlates of implicit aesthetic experience.

    Science.gov (United States)

    Wang, Xiaoyi; Huang, Yujing; Ma, Qingguo; Li, Nan

    2012-10-03

    Using event-related potential measures, the present study investigated the affective responses to aesthetic experience. To differentiate the objective aesthetic value from subjective aesthetic evaluation, an amended oddball task was used in which pendant pictures were presented as frequent nontarget stimuli, whereas the landscape pictures were presented as a rare target. The pendant pictures were chosen from the largest online store in China and divided into beautiful and less beautiful conditions by the sales ranking. A positive component, P2, was recorded for each condition on the participants' frontal, central and parietal scalp areas. Less beautiful pendants elicited greater amplitudes of P2 than the beautiful ones. This indicates that emotion arousal seems to occur at the early stage of processing of aesthetics and can be detected by the P2 component, implying that the event-related potential methodology may be a more sensitive measure of the beauty-related attention bias. From the perspective of artwork design and marketing, our finding also shows that P2 can potentially be used as a reference measure in consumer aesthetic experience.

  3. Source Space Analysis of Event-Related Dynamic Reorganization of Brain Networks

    Directory of Open Access Journals (Sweden)

    Andreas A. Ioannides

    2012-01-01

    Full Text Available How the brain works is nowadays synonymous with how different parts of the brain work together and the derivation of mathematical descriptions for the functional connectivity patterns that can be objectively derived from data of different neuroimaging techniques. In most cases static networks are studied, often relying on resting state recordings. Here, we present a quantitative study of dynamic reconfiguration of connectivity for event-related experiments. Our motivation is the development of a methodology that can be used for personalized monitoring of brain activity. In line with this motivation, we use data with visual stimuli from a typical subject that participated in different experiments that were previously analyzed with traditional methods. The earlier studies identified well-defined changes in specific brain areas at specific latencies related to attention, properties of stimuli, and tasks demands. Using a recently introduced methodology, we track the event-related changes in network organization, at source space level, thus providing a more global and complete view of the stages of processing associated with the regional changes in activity. The results suggest the time evolving modularity as an additional brain code that is accessible with noninvasive means and hence available for personalized monitoring and clinical applications.

  4. Event-related delta, theta, alpha and gamma correlates to auditory oddball processing during Vipassana meditation

    Science.gov (United States)

    Delorme, Arnaud; Polich, John

    2013-01-01

    Long-term Vipassana meditators sat in meditation vs. a control (instructed mind wandering) states for 25 min, electroencephalography (EEG) was recorded and condition order counterbalanced. For the last 4 min, a three-stimulus auditory oddball series was presented during both meditation and control periods through headphones and no task imposed. Time-frequency analysis demonstrated that meditation relative to the control condition evinced decreased evoked delta (2–4 Hz) power to distracter stimuli concomitantly with a greater event-related reduction of late (500–900 ms) alpha-1 (8–10 Hz) activity, which indexed altered dynamics of attentional engagement to distracters. Additionally, standard stimuli were associated with increased early event-related alpha phase synchrony (inter-trial coherence) and evoked theta (4–8 Hz) phase synchrony, suggesting enhanced processing of the habituated standard background stimuli. Finally, during meditation, there was a greater differential early-evoked gamma power to the different stimulus classes. Correlation analysis indicated that this effect stemmed from a meditation state-related increase in early distracter-evoked gamma power and phase synchrony specific to longer-term expert practitioners. The findings suggest that Vipassana meditation evokes a brain state of enhanced perceptual clarity and decreased automated reactivity. PMID:22648958

  5. Event-related potentials indicate bi-hemispherical changes in speech sound processing during aphasia rehabilitation.

    Science.gov (United States)

    Becker, Frank; Reinvang, Ivar

    2007-10-01

    To investigate changes in brain activation related to tone and speech sound processing during aphasia rehabilitation. Longitudinal study investigating patients with stroke, subarachnoid hemorrhage and traumatic brain injury 3 and 7 months post-injury. Eight patients with aphasia, reflecting a wide range of auditory comprehension impairment. Token test and Norwegian Basic Aphasia Assessment were used to measure auditory comprehension function. Brain event-related potentials were recorded in passive paradigms with harmonically rich tones and syllables in order to obtain the mismatch negativity component that reflects automatic stimulus discrimination. In an active syllable discrimination paradigm, stimulus feature integration (N1), attended stimulus discrimination and classification (N2), and target detection (P3) were studied. Auditory comprehension scores improved approximately 10% during the observation period. Ipsilesional frontal P3- and N2-amplitude increased significantly. A significant shift in topographical distribution from the contralesional to the ipsilesional hemisphere was observed for the N2 component. The study of individual waveforms indicates inter-individual differences in reorganization after brain injury. Hemispherical distribution of brain activation correlating with speech sound processing in aphasia can change during the first months after brain injury. Event-related potentials are a potentially useful method for detecting individual activation patterns relevant to recovery in aphasia rehabilitation.

  6. Emotional Granularity Effects on Event-Related Brain Potentials during Affective Picture Processing.

    Science.gov (United States)

    Lee, Ja Y; Lindquist, Kristen A; Nam, Chang S

    2017-01-01

    There is debate about whether emotional granularity, the tendency to label emotions in a nuanced and specific manner, is merely a product of labeling abilities, or a systematic difference in the experience of emotion during emotionally evocative events. According to the Conceptual Act Theory of Emotion (CAT) (Barrett, 2006), emotional granularity is due to the latter and is a product of on-going temporal differences in how individuals categorize and thus make meaning of their affective states. To address this question, the present study investigated the effects of individual differences in emotional granularity on electroencephalography-based brain activity during the experience of emotion in response to affective images. Event-related potentials (ERP) and event-related desynchronization and synchronization (ERD/ERS) analysis techniques were used. We found that ERP responses during the very early (60-90 ms), middle (270-300 ms), and later (540-570 ms) moments of stimulus presentation were associated with individuals' level of granularity. We also observed that highly granular individuals, compared to lowly granular individuals, exhibited relatively stable desynchronization of alpha power (8-12 Hz) and synchronization of gamma power (30-50 Hz) during the 3 s of stimulus presentation. Overall, our results suggest that emotional granularity is related to differences in neural processing throughout emotional experiences and that high granularity could be associated with access to executive control resources and a more habitual processing of affective stimuli, or a kind of "emotional complexity." Implications for models of emotion are also discussed.

  7. The interrelationship between movement and cognition: θ rhythm and the P300 event-related potential.

    Science.gov (United States)

    Shin, Jonghan

    2011-07-01

    The relationship among brain electrophysiological activity, motor activity, and cognition has been a matter of great interest. For example, it has been discussed whether hippocampal theta rhythm reflects motor activity or cognitive activity, whereas it is widely accepted that the P300 event-related potential (ERP) reflects cognitive processes such as updating working memory. Here, we investigated the interrelationships among motor activity, hippocampal theta rhythm, and hippocampal P300 ERP using electrophysiological and behavioral data recorded from rats performing an auditory discrimination task (i.e., the auditory oddball paradigm) in a chamber with and without a running-wheel. We found that the hippocampal theta rhythm generated during locomotion codes information about self-motion, and event-related increases in hippocampal theta rhythm observed when rats performed the auditory discrimination cognitive task reflect a change in motor behavior after learning the cognitive task. Interestingly, the hippocampal P300 ERP occurred coincidently with increases in the power and frequency of hippocampal theta rhythm. In addition, we found that changes in theta rhythm observed during spontaneous wheel running without performing a cognitive task as well as when performing the cognitive task are associated with changes in delta- and gamma-band EEG activities. These major findings are discussed with respect to current hypotheses regarding P300 ERP and theta-, delta-, and gamma-band EEG activities in brain functions. Copyright © 2010 Wiley-Liss, Inc.

  8. Q’eros, peru: the regeneration of cosmological relationships and specific identities through Music

    Directory of Open Access Journals (Sweden)

    Holly Wissler

    2010-12-01

    Full Text Available One of the principal purposes of Q’eros music is to actively regenerate and re-create good relationships with the cosmos and the spirit world they believe in. In this paper, I explore how both the Q’eros’ indigenous songs as well as their newly-adopted music and dance for Peru’s largest pilgrimage, Qoyllurit’i, achieve efficacy of purpose through similar techniques of sound production and aesthetics. Even though the specific musical traits (structure, scale, and instrumentation of both musical styles are significantly different, I address how Q’eros’ musical production of both types share the same focus and serve the same end-goals, whether the ritual is an intimate one within the community or shared with thousands of other people from the greater region. In addition, the performance of both styles of music serve as specific identity markers for the Q’eros depending on their contextual use and the identity desired at the time. In other words, the Q’eros’ musical choices allow them to shift identities between traditional Q’eros in their home community and misti (mestizo in Qoyllurit’i.

  9. The Hubble Space Telescope's Student ERO Pilot Project: Implementing Formal and Informal Collaborative Projects

    Science.gov (United States)

    Eisenhamer, Bonnie; Ryer, H.; McCallister, D.; Taylor, J.; Bishop, M.

    2010-05-01

    The Hubble Space Telescope's Early Release Observations (EROs) were revealed to the public on September 9, 2009, and K-12 students and educators in six states across the country are joining in the celebration. Students and educators in Maryland, Ohio, New York, California, New Mexico, and Delaware have been invited to participate in the Hubble Space Telescope's Student ERO Pilot Project. This is an interdisciplinary project created by STScI's Office of Public Outreach in which students research the four ERO objects and create various types of projects. In recognition of their participation, the projects are displayed at host institutions in each state (museum, science center, school, planetarium or library) during a special public event for participating students, their families, and teachers. As part of its evaluation program, STScI's Office of Public Outreach has been conducting an evaluation of the project to determine the viability and potential of conducting large-scale, formal/informal collaborative projects in the future. This poster will highlight preliminary findings and share lessons learned.

  10. De-noising with a SOCK can improve the performance of event-related ICA.

    Science.gov (United States)

    Bhaganagarapu, Kaushik; Jackson, Graeme D; Abbott, David F

    2014-01-01

    Event-related ICA (eICA) is a partially data-driven analysis method for event-related fMRI that is particularly suited to analysis of simultaneous EEG-fMRI of patients with epilepsy. EEG-fMRI studies in epileptic patients are typically analyzed using the general linear model (GLM), often with assumption that the onset and offset of neuronal activity match EEG event onset and offset, the neuronal activation is sustained at a constant level throughout the epileptiform event and that associated fMRI signal changes follow the canonical HRF. The eICA method allows for less constrained analyses capable of detecting early, non-canonical responses. A key step of eICA is the initial deconvolution which can be confounded by various sources of structured noise present in the fMRI signal. To help overcome this, we have extend the eICA procedure by utilizing a fully standalone and automated fMRI de-noising procedure to process the fMRI data from an EEG-fMRI acquisition prior to running eICA. Specifically we first apply ICA to the entire fMRI time-series and use a classifier to remove noise-related components. The automated objective de-noiser, "Spatially Organized Component Klassificator" (SOCK) is used; it has previously been shown to distinguish a substantial fraction of noise from true activation, without rejecting the latter, in resting-state fMRI. A second ICA is then performed, this time on the event-related response estimates derived from the denoised data (according to the usual eICA procedure). We hypothesize that SOCK + eICA has the potential to be more sensitive than eICA alone. We test the effectiveness of SOCK by comparing activation obtained in an eICA analysis of EEG-fMRI data with and without the use of SOCK for 14 patients with rolandic epilepsy who exhibited stereotypical IEDs arising from a focus in the rolandic fissure.

  11. De-noising with a SOCK can improve the performance of event-related ICA

    Directory of Open Access Journals (Sweden)

    Kaushik eBhaganagarapu

    2014-09-01

    Full Text Available Event-related ICA (eICA is a partially data-driven analysis method for event-related fMRI that is particularly suited to analysis of simultaneous EEG-fMRI of patients with epilepsy. EEG-fMRI studies in epileptic patients are typically analyzed using the general linear model (GLM, often with assumption that the onset and o□set of neuronal activity match EEG event onset and o□set, the neuronal activation is sustained at a constant level throughout the epileptiform event and that associated fMRI signal changes follow the canonical HRF. The eICA method allows for less constrained analyses capable of detecting early, non-canonical responses. A key step of eICA is the initial deconvolution which can be confounded by various sources of structured noise present in the fMRI signal. To help overcome this, we have extend the eICA procedure by utilizing a fully standalone and automated fMRI de-noising procedure to process the fMRI data from an EEG-fMRI acquisition prior to running eICA. Specifically we first apply ICA to the entire fMRI time-series and use a classifier to remove noise-related components. The automated objective de-noiser, Spatially Organised Component Klassificator (SOCK is used; it has previously been shown to distinguish a substantial fraction of noise from true activation, without rejecting the latter, in resting-state fMRI. A second ICA is then performed, this time on the event-related response estimates derived from the denoised data (according to the usual eICA procedure. We hypothesize that SOCK + eICA has the potential to be more sensitive than eICA alone. We test the e□effectiveness of SOCK by comparing activation obtained in an eICA analysis of EEG-fMRI data with and without the use of SOCK for 14 patients with rolandic epilepsy who exhibited stereotypical IEDs arising from a focus in the rolandic fissure.

  12. Word and picture processing in children: an event-related potential study.

    Science.gov (United States)

    Coch, Donna; Maron, Leeza; Wolf, Maryanne; Holcomb, Phillip J

    2002-01-01

    In an investigation of the N400 component, event-related potentials (ERPs) elicited by 4 types of word stimuli (real words, pseudowords, random letter strings, and false fonts) and 3 types of picture stimuli (real pictures, pseudopictures, and picture parts) presented in separate lists were recorded from 10- and 11-year-old children. All types of word stimuli elicited an anteriorly distributed negativity peaking at about 400 msec (antN400). Words and pseudowords elicited similar ERPs, whereas ERPs to letter strings differed from those to both pseudowords and false fonts. All types of picture stimuli elicited dual anterior negativities (N350 and N430). Real pictures and pseudopictures elicited similar ERPs, whereas pseudopictures and picture parts elicited asymmetrical processing. The results are discussed in terms of increased sensitivity to and dependence on context in children.

  13. The hierarchy of task decision and response selection: a task-switching event related potentials study.

    Science.gov (United States)

    Braverman, Ami; Berger, Andrea; Meiran, Nachshon

    2014-07-01

    According to "hierarchical" multi-step theories, response selection is preceded by a decision regarding which task rule should be executed. Other theories assume a "flat" single-step architecture in which task information and stimulus information are simultaneously considered. Using task switching, the authors independently manipulated two kinds of conflict: task conflict (with information that potentially triggers the relevant or the competing task rule/identity) and response conflict (with information that potentially triggers the relevant or the competing response code/motor response). Event related potentials indicated that the task conflict effect began before the response conflict effect and carried on in parallel with it. These results are more in line with the hierarchical view. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. On the origin of event-related potentials indexing covert attentional selection during visual search.

    Science.gov (United States)

    Cohen, Jeremiah Y; Heitz, Richard P; Schall, Jeffrey D; Woodman, Geoffrey F

    2009-10-01

    Despite nearly a century of electrophysiological studies recording extracranially from humans and intracranially from monkeys, the neural generators of nearly all human event-related potentials (ERPs) have not been definitively localized. We recorded an attention-related ERP component, known as the N2pc, simultaneously with intracranial spikes and local field potentials (LFPs) in macaques to test the hypothesis that an attentional-control structure, the frontal eye field (FEF), contributed to the generation of the macaque homologue of the N2pc (m-N2pc). While macaques performed a difficult visual search task, the search target was selected earliest by spikes from single FEF neurons, later by FEF LFPs, and latest by the m-N2pc. This neurochronometric comparison provides an empirical bridge connecting macaque and human experiments and a step toward localizing the neural generator of this important attention-related ERP component.

  15. Bilingualism and increased attention to speech: Evidence from event-related potentials.

    Science.gov (United States)

    Kuipers, Jan Rouke; Thierry, Guillaume

    2015-10-01

    A number of studies have shown that from an early age, bilinguals outperform their monolingual peers on executive control tasks. We previously found that bilingual children and adults also display greater attention to unexpected language switches within speech. Here, we investigated the effect of a bilingual upbringing on speech perception in one language. We recorded monolingual and bilingual toddlers' event-related potentials (ERPs) to spoken words preceded by pictures. Words matching the picture prime elicited an early frontal positivity in bilingual participants only, whereas later ERP amplitudes associated with semantic processing did not differ between groups. These results add to the growing body of evidence that bilingualism increases overall attention during speech perception whilst semantic integration is unaffected. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  16. Spatial and Semantic Processing between Audition and Vision: An Event-Related Potential Study

    Directory of Open Access Journals (Sweden)

    Xiaoxi Chen

    2011-10-01

    Full Text Available Using a crossmodal priming paradigm, this study investigated how the brain bound the spatial and semantic features in multisensory processing. The visual stimuli (pictures of animals were presented after the auditory stimuli (sounds of animals, and the stimuli from different modalities may match spatially (or semantically or not. Participants were required to detect the head orientation of the visual target (an oddball paradigm. The event-related potentials (ERPs to the visual stimuli was enhanced by spatial attention (150–170 ms irrespectively of semantic information. The early crossmodal attention effect for the visual stimuli was more negative in the spatial-congruent condition than in the spatial-incongruent condition. By contrast, the later effects of spatial ERPs were significant only for the semantic- congruent condition (250–300 ms. These findings indicated that spatial attention modulated early visual processing, and semantic and spatial features were simultaneously used to orient attention and modulate later processing stages.

  17. Conveying the concept of movement in music: An event-related brain potential study.

    Science.gov (United States)

    Zhou, Linshu; Jiang, Cunmei; Wu, Yingying; Yang, Yufang

    2015-10-01

    This study on event-related brain potential investigated whether music can convey the concept of movement. Using a semantic priming paradigm, natural musical excerpts were presented to non-musicians, followed by semantically congruent or incongruent pictures that depicted objects either in motion or at rest. The priming effects were tested in object decision and implicit recognition tasks to distinguish the effects of automatic conceptual activation from response competition. Results showed that in both tasks, pictures that were incongruent to preceding musical excerpts elicited larger N400 than congruent pictures, suggesting that music can prime the representations of movement concepts. Results of the multiple regression analysis showed that movement expression could be well predicted by specific acoustic and musical features, indicating the associations between music per se and the processing of iconic musical meaning. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Event-related brain responses while listening to entire pieces of music

    DEFF Research Database (Denmark)

    Poikonen, Hanna; Alluri, Vinoo; Brattico, Elvira

    2016-01-01

    Brain responses to discrete short sounds have been studied intensively using the event-related potential (ERP) method, in which the electroencephalogram (EEG) signal is divided into epochs time-locked to stimuli of interest. Here we introduce and apply a novel technique which enables one to isolate...... ERPs in human elicited by continuous music. The ERPs were recorded during listening to a Tango Nuevo piece, a deep techno track and an acoustic lullaby. Acoustic features related to timbre, harmony, and dynamics of the audio signal were computationally extracted from the musical pieces. Negative...... changes in these musical features, long phases of low values that precede a rapid increase – and that we will call Preceding Low-Feature Phases – followed by a rapid increase enhanced the amplitudes of N100 and P200 responses. These ERP responses resembled those to simpler sounds, making it possible...

  19. Modifications of recognition memory processes in preterm children: an event-related potential study.

    Science.gov (United States)

    Kipp, Kerstin H; Mecklinger, Axel; Brunnemann, Nicole; Shamdeen, Mohammed G; Meng-Hentschel, Juliane; Gortner, Ludwig

    2015-01-01

    Prematurity may cause hippocampal compromise. Therefore, hippocampus-dependent memory processes (recollection-based retrieval) may be more impaired than hippocampus-independent processes (familiarity-based retrieval). The memory of 18 children born preterm with reduced hippocampal volumes, without neonatal complications (weeks of gestation < 34, weight < 1,600 g), and 15 controls (8-10 years) was tested using an item recognition task. While groups were equal in memory performance, dissociation was found: The event-related potential (ERP) correlate of familiarity was intact in the preterm group, whereas the correlate of recollection was attenuated. A follow-up experiment ruled out that this was due to general cognitive deficits. Furthermore, gestational age correlated with the ERP index of recollection. Thus, recognition memory in preterm children may be characterized by a compensation of attenuated recollection by familiarity. © 2014 The Authors. Child Development © 2014 Society for Research in Child Development, Inc.

  20. Auditory event-related potentials measured in kindergarten predict later reading problems at school age.

    Science.gov (United States)

    Hämäläinen, Jarmo A; Guttorm, Tomi K; Richardson, Ulla; Alku, Paavo; Lyytinen, Heikki; Leppänen, Paavo H T

    2013-01-01

    Identifying children at risk for reading problems or dyslexia at kindergarten age could improve support for beginning readers. Brain event-related potentials (ERPs) were measured for temporally complex pseudowords and corresponding non-speech stimuli from 6.5-year-old children who participated in behavioral literacy tests again at 9 years in the second grade. Children who had reading problems at school age had larger N250 responses to speech and non-speech stimuli particularly at the left hemisphere. The brain responses also correlated with reading skills. The results suggest that atypical auditory and speech processing are a neural-level risk factor for future reading problems. [Supplementary material is available for this article. Go to the publisher's online edition of Developmental Neuropsychology for the following free supplemental resources: Sound files used in the experiments. Three speech sounds and corresponding non-speech sounds with short, intermediate, and long gaps].

  1. Analysis of extrinsic and intrinsic factors affecting event related desynchronization production.

    Science.gov (United States)

    Takata, Yohei; Kondo, Toshiyuki; Saeki, Midori; Izawa, Jun; Takeda, Kotaro; Otaka, Yohei; It, Koji

    2012-01-01

    Recently there has been an increase in the number of stroke patients with motor paralysis. Appropriate re-afferent sensory feedback synchronized with a voluntary motor intention would be effective for promoting neural plasticity in the stroke rehabilitation. Therefore, BCI technology is considered to be a promising approach in the neuro-rehabilitation. To estimate human motor intention, an event-related desynchronization (ERD), a feature of electroencephalogram (EEG) evoked by motor execution or motor imagery is usually used. However, there exists various factors that affect ERD production, and its neural mechanism is still an open question. As a preliminary stage, we evaluate mutual effects of intrinsic (voluntary motor imagery) and extrinsic (visual and somatosensory stimuli) factors on the ERD production. Experimental results indicate that these three factors are not always additively interacting with each other and affecting the ERD production.

  2. An event-related potential study of supramodal attentional control and crossmodal attention effects.

    Science.gov (United States)

    Green, Jessica J; McDonald, John J

    2006-03-01

    We conducted two audiovisual experiments to determine whether event-related potential (ERP) components elicited by attention-directing cues reflect supramodal attentional control. Symbolic visual cues were used to direct attention prior to auditory targets in Experiment 1, and symbolic auditory cues were used to direct attention prior to visual targets in Experiment 2. Different patterns of cue ERPs were found in the two experiments. A frontal negativity called the ADAN was absent in Experiment 2, which indicates that this component does not reflect supramodal attentional control. A posterior positivity called the LDAP was observed in both experiments but was focused more posteriorly over the occipital scalp in Experiment 2. This component appears to reflect multiple processes, including visual processes involved in location marking and target preparation as well as supramodal processes involved in attentional control.

  3. Event-related potentials, emotion, and emotion regulation: an integrative review.

    Science.gov (United States)

    Hajcak, Greg; MacNamara, Annmarie; Olvet, Doreen M

    2010-01-01

    Progress in the study of emotion and emotion regulation has increasingly been informed by neuroscientific methods. This article focuses on two components of the event-related potential (ERP)--the P300 and the late positive potential (LPP)--and how they can be used to understand the interaction between the more automatic and controlled processing of emotional stimuli. Research is reviewed exploring: the dynamics of emotional response as indexed at early and late latencies; neurobiological correlates of emotional response; individual and developmental differences; ways in which the LPP can be utilized as a measure of emotion regulation. Future directions for the application of ERP/electroencephalogram (EEG) in achieving a more complete understanding of emotional processing and its regulation are presented.

  4. Attentional Selection Accompanied by Eye Vergence as Revealed by Event-Related Brain Potentials.

    Science.gov (United States)

    Sole Puig, Maria; Pallarés, Josep Marco; Perez Zapata, Laura; Puigcerver, Laura; Cañete, Josep; Supèr, Hans

    2016-01-01

    Neural mechanisms of attention allow selective sensory information processing. Top-down deployment of visual-spatial attention is conveyed by cortical feedback connections from frontal regions to lower sensory areas modulating late stimulus responses. A recent study reported the occurrence of small eye vergence during orienting top-down attention. Here we assessed a possible link between vergence and attention by comparing visual event related potentials (vERPs) to a cue stimulus that induced attention to shift towards the target location to the vERPs to a no-cue stimulus that did not trigger orienting attention. The results replicate the findings of eye vergence responses during orienting attention and show that the strength and time of eye vergence coincide with the onset and strength of the vERPs when subjects oriented attention. Our findings therefore support the idea that eye vergence relates to and possibly has a role in attentional selection.

  5. Attentional Selection Accompanied by Eye Vergence as Revealed by Event-Related Brain Potentials.

    Directory of Open Access Journals (Sweden)

    Maria Sole Puig

    Full Text Available Neural mechanisms of attention allow selective sensory information processing. Top-down deployment of visual-spatial attention is conveyed by cortical feedback connections from frontal regions to lower sensory areas modulating late stimulus responses. A recent study reported the occurrence of small eye vergence during orienting top-down attention. Here we assessed a possible link between vergence and attention by comparing visual event related potentials (vERPs to a cue stimulus that induced attention to shift towards the target location to the vERPs to a no-cue stimulus that did not trigger orienting attention. The results replicate the findings of eye vergence responses during orienting attention and show that the strength and time of eye vergence coincide with the onset and strength of the vERPs when subjects oriented attention. Our findings therefore support the idea that eye vergence relates to and possibly has a role in attentional selection.

  6. When mental fatigue maybe characterized by Event Related Potential (P300) during virtual wheelchair navigation.

    Science.gov (United States)

    Lamti, Hachem A; Gorce, Philippe; Ben Khelifa, Mohamed Moncef; Alimi, Adel M

    2016-12-01

    The goal of this study is to investigate the influence of mental fatigue on the event related potential P300 features (maximum pick, minimum amplitude, latency and period) during virtual wheelchair navigation. For this purpose, an experimental environment was set up based on customizable environmental parameters (luminosity, number of obstacles and obstacles velocities). A correlation study between P300 and fatigue ratings was conducted. Finally, the best correlated features supplied three classification algorithms which are MLP (Multi Layer Perceptron), Linear Discriminate Analysis and Support Vector Machine. The results showed that the maximum feature over visual and temporal regions as well as period feature over frontal, fronto-central and visual regions were correlated with mental fatigue levels. In the other hand, minimum amplitude and latency features didn't show any correlation. Among classification techniques, MLP showed the best performance although the differences between classification techniques are minimal. Those findings can help us in order to design suitable mental fatigue based wheelchair control.

  7. A new method for detecting interactions between the senses in event-related potentials

    DEFF Research Database (Denmark)

    Gondan, Matthias; Röder, B.

    2006-01-01

    not contain common activity: This activity would be subtracted twice from one ERP and would, therefore, contaminate the result. In the present study, ERPs to unimodal, bimodal, and trimodal auditory, visual, and tactile stimuli (T) were recorded. We demonstrate that (T + TAV) - (TA + TV) is equivalent to AV......Event-related potentials (ERPs) can be used in multisensory research to determine the point in time when different senses start to interact, for example, the auditory and the visual system. For this purpose, the ERP to bimodal stimuli (AV) is often compared to the sum of the ERPs to auditory (A......) and visual (V) stimuli: AV - (A + V). If the result is non-zero, this is interpreted as an indicator for multisensory interactions. Using this method, several studies have demonstrated auditory-visual interactions as early as 50 ms after stimulus onset. The subtraction requires that A, V, and AV do...

  8. The delay effect on outcome evaluation: results from an Event-related Potential study

    Directory of Open Access Journals (Sweden)

    Chen eQu

    2013-11-01

    Full Text Available Behavioral studies demonstrate that the timing of receiving gains or losses affects decision-making, a phenomenon known as temporal discounting, as participants are inclined to prefer immediate rewards over delayed ones and vice versa for losses. The present study used the event-related potential (ERP technique with a simple gambling task to investigate how delayed rewards and losses affected the brain activity in outcome evaluations made by 20 young adults. Statistical analysis revealed a larger feedback related negativity (FRN effect between loss and gain following immediate outcomes than following future outcomes. In addition, delay impacted FRN only in gain conditions, with delayed winning eliciting a more negative FRN than immediatewinning. These results suggest that temporal discounting and sign effect could be encoded in the FRN in the early stage of outcome evaluation.

  9. P300 component of event-related potentials in persons with asperger disorder.

    Science.gov (United States)

    Iwanami, Akira; Okajima, Yuka; Ota, Haruhisa; Tani, Masayuki; Yamada, Takashi; Yamagata, Bun; Hashimoto, Ryuichiro; Kanai, Chieko; Takashio, Osamu; Inamoto, Atsuko; Ono, Taisei; Takayama, Yukiko; Kato, Nobumasa

    2014-10-01

    In the present study, we investigated auditory event-related potentials in adults with Asperger disorder and normal controls using an auditory oddball task and a novelty oddball task. Task performance and the latencies of P300 evoked by both target and novel stimuli in the two tasks did not differ between the two groups. Analysis of variance revealed that there was a significant interaction effect between group and electrode site on the mean amplitude of the P300 evoked by novel stimuli, which indicated that there was an altered distribution of the P300 in persons with Asperger disorder. In contrast, there was no significant interaction effect on the mean P300 amplitude elicited by target stimuli. Considering that P300 comprises two main subcomponents, frontal-central-dominant P3a and parietal-dominant P3b, our results suggested that persons with Asperger disorder have enhanced amplitude of P3a, which indicated activated prefrontal function in this task.

  10. Predicting Reading Growth with Event-Related Potentials: Thinking Differently about Indexing "Responsiveness"

    Science.gov (United States)

    Lemons, Christopher J; Key, Alexandra P F; Fuchs, Douglas; Yoder, Paul J; Fuchs, Lynn S; Compton, Donald L; Williams, Susan M; Bouton, Bobette

    2010-06-01

    The purpose of this study was to determine if event-related potential (ERP) data collected during three reading-related tasks (Letter Sound Matching, Nonword Rhyming, and Nonword Reading) could be used to predict short-term reading growth on a curriculum-based measure of word identification fluency over 19 weeks in a sample of 29 first-grade children. Results indicate that ERP responses to the Letter Sound Matching task were predictive of reading change and remained so after controlling for two previously validated behavioral predictors of reading, Rapid Letter Naming and Segmenting. ERP data for the other tasks were not correlated with reading change. The potential for cognitive neuroscience to enhance current methods of indexing responsiveness in a response-to-intervention (RTI) model is discussed.

  11. Pitch Processing in Tonal-Language-Speaking Children with Autism: An Event-Related Potential Study.

    Science.gov (United States)

    Yu, Luodi; Fan, Yuebo; Deng, Zhizhou; Huang, Dan; Wang, Suiping; Zhang, Yang

    2015-11-01

    The present study investigated pitch processing in Mandarin-speaking children with autism using event-related potential measures. Two experiments were designed to test how acoustic, phonetic and semantic properties of the stimuli contributed to the neural responses for pitch change detection and involuntary attentional orienting. In comparison with age-matched (6-12 years) typically developing controls (16 participants in Experiment 1, 18 in Experiment 2), children with autism (18 participants in Experiment 1, 16 in Experiment 2) showed enhanced neural discriminatory sensitivity in the nonspeech conditions but not for speech stimuli. The results indicate domain specificity of enhanced pitch processing in autism, which may interfere with lexical tone acquisition and language development for children who speak a tonal language.

  12. A comparative study of event-related coupling patterns during an auditory oddball task in schizophrenia

    Science.gov (United States)

    Bachiller, Alejandro; Poza, Jesús; Gómez, Carlos; Molina, Vicente; Suazo, Vanessa; Hornero, Roberto

    2015-02-01

    Objective. The aim of this research is to explore the coupling patterns of brain dynamics during an auditory oddball task in schizophrenia (SCH). Approach. Event-related electroencephalographic (ERP) activity was recorded from 20 SCH patients and 20 healthy controls. The coupling changes between auditory response and pre-stimulus baseline were calculated in conventional EEG frequency bands (theta, alpha, beta-1, beta-2 and gamma), using three coupling measures: coherence, phase-locking value and Euclidean distance. Main results. Our results showed a statistically significant increase from baseline to response in theta coupling and a statistically significant decrease in beta-2 coupling in controls. No statistically significant changes were observed in SCH patients. Significance. Our findings support the aberrant salience hypothesis, since SCH patients failed to change their coupling dynamics between stimulus response and baseline when performing an auditory cognitive task. This result may reflect an impaired communication among neural areas, which may be related to abnormal cognitive functions.

  13. Event-related brain potential evidence for animacy processing asymmetries during sentence comprehension.

    Science.gov (United States)

    Nieuwland, Mante S; Martin, Andrea E; Carreiras, Manuel

    2013-08-01

    The animacy distinction is deeply rooted in the language faculty. A key example is differential object marking, the phenomenon where animate sentential objects receive specific marking. We used event-related potentials to examine the neural processing consequences of case-marking violations on animate and inanimate direct objects in Spanish. Inanimate objects with incorrect prepositional case marker 'a' ('al suelo') elicited a P600 effect compared to unmarked objects, consistent with previous literature. However, animate objects without the required prepositional case marker ('el obispo') only elicited an N400 effect compared to marked objects. This novel finding, an exclusive N400 modulation by a straightforward grammatical rule violation, does not follow from extant neurocognitive models of sentence processing, and mirrors unexpected "semantic P600" effects for thematically problematic sentences. These results may reflect animacy asymmetry in competition for argument prominence: following the article, thematic interpretation difficulties are elicited only by unexpectedly animate objects. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. Effects of context on implicit and explicit lexical knowledge: an event-related potential study.

    Science.gov (United States)

    Choi, Sungmook; Kim, Jingu; Ryu, Kwangmin

    2014-10-01

    Although much is known about how contextualized and decontextualized learning affects explicit lexical knowledge, how these learning conditions contribute to implicit lexical knowledge remains unclear. To address this problem, Korean high school students were instructed to learn 30 English words by reading meaningful passages (i.e., in context) and another 30 English words using a wordlist (i.e., out of context). Five weeks later, implicit lexical knowledge was gauged by reaction time and the N400 event-related brain potential component, and explicit lexical knowledge was assessed with an explicit behavioral measure. Results showed that neither learning type was superior to the other in terms of implicit lexical knowledge acquisition, whereas learning words out of context was more effective than learning words in context for establishing explicit lexical knowledge. These results suggest that the presence or absence of context may lead to dissociation in the development of implicit and explicit lexical knowledge. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Memory and event-related potentials for rapidly presented emotional pictures

    Science.gov (United States)

    Bradley, Margaret M.; Lang, Peter J.

    2010-01-01

    Dense array event-related potentials (ERPs) and memory performance were assessed following rapid serial visual presentation (RSVP) of emotional and neutral pictures. Despite the extremely brief presentation, emotionally arousing pictures prompted an enhanced negative voltage over occipital sensors, compared to neutral pictures, replicating previous encoding effects. Emotionally arousing pictures were also remembered better in a subsequent recognition test, with higher hit rates and better discrimination performance. ERPs measured during the recognition test showed both an early (250–350 ms) frontally distributed difference between hits and correct rejections, and a later (400–500 ms), more centrally distributed difference, consistent with effects of recognition on ERPs typically found using slower presentation rates. The data are consistent with the hypothesis that features of affective pictures pop out during rapid serial visual presentation, prompting better memory performance. PMID:20628736

  16. Neuroprotection against vascular dementia after acupuncture combined with donepezil hydrochloride: P300 event related potential

    Directory of Open Access Journals (Sweden)

    Qiang Liu

    2016-01-01

    Full Text Available Acupuncture can be used to treat various nervous system diseases. Here, 168 vascular dementia patients were orally administered donepezil hydrochloride alone (5 mg/day, once a day for 56 days, or combined with acupuncture at Shenting (DU24, Tianzhu (BL10, Sishencong (Extra, Yintang (Extra, Renzhong (DU26, Neiguan (PC6, Shenmen (HT7, Fengchi (GB20, Wangu (GB12 and Baihui (DU20 (once a day for 56 days. Compared with donepezil hydrochloride alone, P300 event related potential latency was shorter with an increased amplitude in patients treated with donepezil hydrochloride and acupuncture. Mini-Mental State Examination score was also higher. Moreover, these differences in P300 latency were identified within different infarcted regions in patients treated with donepezil hydrochloride and acupuncture. These findings indicate that acupuncture combined with donepezil hydrochloride noticeably improves cognitive function in patients with vascular dementia, and exerts neuroprotective effects against vascular dementia.

  17. The neural processing of fearful faces without attention and consciousness: an event-related potential study.

    Science.gov (United States)

    Wang, Lili; Fu, Shimin; Feng, Chunliang; Luo, Wenbo; Zhu, Xiangru; Luo, Yue-jia

    2012-01-11

    To investigate whether the non-conscious processing of fearful faces exist in unattended condition, event-related potentials (ERPs) were recorded in a facial expression detection task. Participants were asked to discriminate the facial expressions (fearful or neutral) at the attended location. Unattended faces were associated with a response that was either congruent or in conflict with the response to the attended face. ERP results showed that the trials with response conflict between attended and unattended faces enhanced the amplitude of the P3 component when the neutral face was presented at attended location and the fearful face was presented at the unattended location. Our findings imply that the non-conscious fearful faces can be processed in the unattended condition. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  18. Online Motor Imagery Training Effect for the Appearance of Event Related Desynchronization (ERD)

    Science.gov (United States)

    Takahashi, Mitsuru; Gouko, Manabu; Ito, Koji

    Stroke patients have some motor deficits, but they can regain their motor abilities by rehabilitation. In the aspect of rehabilitation, voluntary movement is very important. We propose a system which can make a closed loop in brain for stroke patients like voluntary movement. Event Related Desynchronization (ERD) is used to extract patients' motor intention, and then Functional Electrical Stimulation (FES) stimuls their paralyzed muscles. In many Brain Computer Interface (BCI) researches, subjects are trained for several months or years to do the task, because of the difficulty to extract clear ERD without training. Thinking about applying for stroke patients, motor imagery training should be shorter, because of the brain plasticity. We did a pilot study about the effect of visual feedback training for three days with healthy subjects. The result indicated that ERD could be clearly extracted in three days, but the training effect differs in each subjects.

  19. A wavelet based algorithm for the identification of oscillatory event-related potential components.

    Science.gov (United States)

    Aniyan, Arun Kumar; Philip, Ninan Sajeeth; Samar, Vincent J; Desjardins, James A; Segalowitz, Sidney J

    2014-08-15

    Event related potentials (ERPs) are very feeble alterations in the ongoing electroencephalogram (EEG) and their detection is a challenging problem. Based on the unique time-based parameters derived from wavelet coefficients and the asymmetry property of wavelets a novel algorithm to separate ERP components in single-trial EEG data is described. Though illustrated as a specific application to N170 ERP detection, the algorithm is a generalized approach that can be easily adapted to isolate different kinds of ERP components. The algorithm detected the N170 ERP component with a high level of accuracy. We demonstrate that the asymmetry method is more accurate than the matching wavelet algorithm and t-CWT method by 48.67 and 8.03 percent, respectively. This paper provides an off-line demonstration of the algorithm and considers issues related to the extension of the algorithm to real-time applications. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Hostile attribution biases for relationally provocative situations and event-related potentials.

    Science.gov (United States)

    Godleski, Stephanie A; Ostrov, Jamie M; Houston, Rebecca J; Schlienz, Nicolas J

    2010-04-01

    This exploratory study investigates how hostile attribution biases for relationally provocative situations may be related to neurocognitive processing using the P300 event-related potential. Participants were 112 (45 women) emerging adults enrolled in a large, public university in upstate New York. Participants completed self-report measures on relational aggression and hostile attribution biases and performed an auditory perseveration task to elicit the P300. It was found that hostile attribution biases for relational provocation situations was associated with a larger P300 amplitude above and beyond the role of hostile attribution biases for instrumental situations, relational aggression, and gender. Larger P300 amplitude is interpreted to reflect greater allocation of cognitive resources or enhanced "attending" to salient stimuli. Implications for methodological approaches to studying aggression and hostile attribution biases and for theory are discussed, as well as implications for the fields of developmental psychology and psychopathology. Copyright 2010 Elsevier B.V. All rights reserved.

  1. Multiple sources of positive- and negative-priming effects: an event-related potential study.

    Science.gov (United States)

    Gibbons, Henning; Rammsayer, Thomas H; Stahl, Jutta

    2006-01-01

    Event-related potential correlates of positive priming (PP) and negative priming (NP) were investigated in order to further elucidate the cognitive mechanisms involved. Thirty-six participants performed both an identity- and a location-based priming task. Repeating the target stimulus/location from the immediately preceding display produced behavioral PP. With localization, but not with identification, behavioral NP was observed when the target stimulus/location matched the preceding distractor stimulus/location. Smaller P300 amplitude accompanied identity-based PP, suggesting persisting target-specific activation. The lateralized readiness potential, an index of correct/incorrect response activation, indicated persisting central motor activation as another source of PP. Both location-based PP and NP were accompanied by reduced P1/N1 and P300 amplitudes, pointing to the involvement of inhibition of return in location-based priming. The results support the view that multiple brain processes underlie behavioral priming.

  2. Crossmodal effects of Guqin and piano music on selective attention: an event-related potential study.

    Science.gov (United States)

    Zhu, Weina; Zhang, Junjun; Ding, Xiaojun; Zhou, Changle; Ma, Yuanye; Xu, Dan

    2009-11-27

    To compare the effects of music from different cultural environments (Guqin: Chinese music; piano: Western music) on crossmodal selective attention, behavioral and event-related potential (ERP) data in a standard two-stimulus visual oddball task were recorded from Chinese subjects in three conditions: silence, Guqin music or piano music background. Visual task data were then compared with auditory task data collected previously. In contrast with the results of the auditory task, the early (N1) and late (P300) stages exhibited no differences between Guqin and piano backgrounds during the visual task. Taking our previous study and this study together, we can conclude that: although the cultural-familiar music influenced selective attention both in the early and late stages, these effects appeared only within a sensory modality (auditory) but not in cross-sensory modalities (visual). Thus, the musical cultural factor is more obvious in intramodal than in crossmodal selective attention.

  3. Parallel Factor Analysis as an exploratory tool for wavelet transformed event-related EEG

    DEFF Research Database (Denmark)

    Mørup, Morten; Hansen, Lars Kai; Hermann, Cristoph S.

    2006-01-01

    -Montes, E., Valdes-Sosa, P.A., Nishiyama, N., Mizuhara, H., Yamaguchi, Y., 2004. Decomposing EEG data into space-time-frequency components using parallel factor analysis. Neuroimage 22, 1035-1045). In this article, PARAFAC is used for the first time to decompose wavelet transformed event-related EEG given...... of frequency transformed multi-channel EEG of channel x frequency x time data. The multi-way decomposition method Parallel Factor (PARAFAC), also named Canonical Decomposition (CANDECOMP), was recently used to decompose the wavelet transformed ongoing EEG of channel x frequency x time (Miwakeichi, F., Martinez......In the decomposition of multi-channel EEG signals, principal component analysis (PCA) and independent component analysis (ICA) have widely been used. However, as both methods are based on handling two-way data, i.e. two-dimensional matrices, multi-way methods might improve the interpretation...

  4. Digital memory encoding in Chinese dyscalculia: An event-related potential study.

    Science.gov (United States)

    Wang, Enguo; Qin, Shutao; Chang, MengYan; Zhu, Xiangru

    2014-10-22

    This study reports the neurophysiological and behavioral correlates of digital memory encoding features in Chinese individuals with and without dyscalculia. Eighteen children with dyscalculia (ages 11.5-13.5) and 18 matched controls were tested, and their event-related potentials (ERPs) were digitally recorded simultaneously with behavioral measures. The results showed that both groups had a significant Dm effect, and this effect was greater in the control group. In the 300-400-ms, 400-500-ms, and 600-700-ms processing stages, both groups showed significant differences of digital memory encoding in the frontal, central, and parietal regions. In the 500-600-ms period, the Dm effect in the control group was significantly greater than that in the dyscalculia group only in the parietal region. These results suggest that individuals with dyscalculia exhibit impaired digital memory encoding and deficits in psychological resource allocation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Influence of sex on P300: an event-related potential electrophysiological study.

    Science.gov (United States)

    Bourisly, Ali K; Pothen, Annie

    2016-02-10

    The primary objective of this study was to further characterize the role of sex, if any, in event-related potentials (ERPs). More specifically, we aimed to investigate sex sensitivity with respect to the P300 ERP. Each female and male study participant underwent an oddball paradigm electroencephalography ERP session. ERP data were subjected to preprocessing and postprocessing, as well as statistical analysis. The results of the study showed that men had larger P300 amplitudes on average for both low-probability and high-probability stimuli compared with women (PP300 latencies on average than did women (PP300 ERP, which may be because of men eliciting higher response inhibition compared with women.

  6. The Use of Auditory Event-Related Potentials in Alzheimer's Disease Diagnosis

    Directory of Open Access Journals (Sweden)

    Fabrizio Vecchio

    2011-01-01

    Full Text Available Event-related potentials (ERPs are important clinical and research instruments in neuropsychiatry, particularly due to their strategic role for the investigation of brain function. These techniques are often underutilized in the evaluation of neurological and psychiatric disorders, but ERPs are noninvasive instruments that directly reflect cortical neuronal activity. Previous studies using the P300, P3a, and MMN components of the ERP to study dementing illness are reviewed. The results suggest that particularly the P300 brain potential is sensitive to Alzheimer's disease processes during its early stages, and that easily performed stimulus discrimination tasks are the clinically most useful. Finally, these data suggest that the P300 ERP can aid in the diagnosis of dementia and may help in the assessment of early Alzheimer's disease.

  7. Neuroprotection against vascular dementia after acupuncture combined with donepezil hydrochloride: P300 event related potential.

    Science.gov (United States)

    Liu, Qiang; Wang, Xiu-Juan; Zhang, Zhe-Cheng; Xue, Rong; Li, Ping; Li, Bo

    2016-03-01

    Acupuncture can be used to treat various nervous system diseases. Here, 168 vascular dementia patients were orally administered donepezil hydrochloride alone (5 mg/day, once a day for 56 days), or combined with acupuncture at Shenting (DU24), Tianzhu (BL10), Sishencong (Extra), Yintang (Extra), Renzhong (DU26), Neiguan (PC6), Shenmen (HT7), Fengchi (GB20), Wangu (GB12) and Baihui (DU20) (once a day for 56 days). Compared with donepezil hydrochloride alone, P300 event related potential latency was shorter with an increased amplitude in patients treated with donepezil hydrochloride and acupuncture. Mini-Mental State Examination score was also higher. Moreover, these differences in P300 latency were identified within different infarcted regions in patients treated with donepezil hydrochloride and acupuncture. These findings indicate that acupuncture combined with donepezil hydrochloride noticeably improves cognitive function in patients with vascular dementia, and exerts neuroprotective effects against vascular dementia.

  8. Experimental Study on Event-Related Potential for Objective Evaluation of Food

    Science.gov (United States)

    Tanaka, Motoshi; Honma, Tomohiro; Inoue, Hiroshi; Niiyama, Yoshitsugu; Takahashi, Toru; Kumagai, Masanori; Akiyama, Yoshinobu

    In order to study the application of event-related potential (ERP) for performing objective evaluation of food, the ERP was measured when subjectively judging the appearance of food by three-grade scale with the opinion “like”, “favorite” and “more favorite”. Sushi and cooked rice were selected as typical foods. Five pictures of each food that the subjects liked were chosen before measurements, and then were used in opinion tests. As a result, the P300 component of the ERP was detected, and the P300 area (surrounded by ERP waveform from the latency 250 to 500ms) became larger when the subjects judged as “more favorite”, which indicates the feasibility of evaluation of food using the ERP.

  9. Memory and event-related potentials for rapidly presented emotional pictures.

    Science.gov (United States)

    Versace, Francesco; Bradley, Margaret M; Lang, Peter J

    2010-08-01

    Dense array event-related potentials (ERPs) and memory performance were assessed following rapid serial visual presentation (RSVP) of emotional and neutral pictures. Despite the extremely brief presentation, emotionally arousing pictures prompted an enhanced negative voltage over occipital sensors, compared to neutral pictures, replicating previous encoding effects. Emotionally arousing pictures were also remembered better in a subsequent recognition test, with higher hit rates and better discrimination performance. ERPs measured during the recognition test showed both an early (250-350 ms) frontally distributed difference between hits and correct rejections, and a later (400-500 ms), more centrally distributed difference, consistent with effects of recognition on ERPs typically found using slower presentation rates. The data are consistent with the hypothesis that features of affective pictures pop out during rapid serial visual presentation, prompting better memory performance.

  10. The correlation between motor impairments and event-related desynchronization during motor imagery in ALS patients

    Directory of Open Access Journals (Sweden)

    Kasahara Takashi

    2012-06-01

    Full Text Available Abstract Background The event-related desynchronization (ERD in EEG is known to appear during motor imagery, and is thought to reflect cortical processing for motor preparation. The aim of this study is to examine the modulation of ERD with motor impairment in ALS patients. ERD during hand motor imagery was obtained from 8 ALS patients with a variety of motor impairments. ERD was also obtained from age-matched 11 healthy control subjects with the same motor task. The magnitude and frequency of ERD were compared between groups for characterization of ALS specific changes. Results The ERD of ALS patients were significantly smaller than those of control subjects. Bulbar function and ERD were negatively correlated in ALS patients. Motor function of the upper extremities did was uncorrelated with ERD. Conclusions ALS patients with worsened bulbar scales may show smaller ERD. Motor function of the upper extremities did was uncorrelated with ERD.

  11. Event related potentials reveal differences between morphological (prefixes) and phonological (syllables) processing of words.

    Science.gov (United States)

    Domínguez, Alberto; Alija, Maira; Cuetos, Fernando; de Vega, Mauel

    2006-11-06

    Behavioral measures in visual priming tasks show opposite effects for syllables and morphemes, which indicate that they are processed by two independent systems. We used event related potentials (ERPs) to explore two priming situations in Spanish: prefix related words (reacción-REFORMA [reaction-reform]), in which prime and target words shared a first syllable that was also a prefix, and syllable related words (regalo-REFORMA [gift-reform.]), in which the shared first syllable was a pseudoprefix in the prime word. Prefix related pairs, unlike syllable related pairs, evoked a very early positivity in reaction to the target (at 150-250ms window), suggesting that the prefix information is immediately available, at a prelexical stage. By contrast, syllable related pairs showed a larger N400 effect. This late negativity may be caused by lateral inhibition among lexical candidates activated in the lexicon by the prime's first syllable.

  12. Phase noise reveals early category-specific modulation of the event-related potentials

    Directory of Open Access Journals (Sweden)

    Kornél eNémeth

    2014-04-01

    Full Text Available Previous studies have found that the amplitude of the early event-related potential (ERP components evoked by faces, such as N170 and P2, changes systematically as a function of noise added to the stimuli. This change has been linked to an increased perceptual processing demand and to enhanced difficulty in perceptual decision making about faces. However, to date it has not yet been tested whether noise manipulation affects the neural correlates of decisions about face and non-face stimuli similarly. To this end, we measured the event-related potentials for faces and cars at three different phase noise levels. Subjects performed the same two-alternative age-discrimination task on stimuli chosen from young-old morphing continua that were created from faces as well as cars and were calibrated to lead to similar performances at each noise-level. Adding phase noise to the stimuli reduced performance and enhanced response latency for the two categories to the same extent. Parallel to that, phase noise reduced the amplitude and prolonged the latency of the face-specific N170 component. The amplitude of the P1 showed category-specific noise dependence: it was enhanced over the right hemisphere for cars and over the left hemisphere for faces as a result of adding phase noise to the stimuli, but remained stable across noise levels for cars over the left and for faces over the right hemisphere. Moreover, noise modulation altered the category-selectivity of the N170, while the P2 ERP component, typically associated with task decision difficulty, was larger for the more noisy stimuli regardless of stimulus category. Our results suggest that the category-specificity of noise-induced modulations of ERP responses starts at around 100 ms post-stimulus.

  13. A cognitive stressor for event-related potential studies: the Portland arithmetic stress task.

    Science.gov (United States)

    Atchley, Rachel; Ellingson, Roger; Klee, Daniel; Memmott, Tabatha; Oken, Barry

    2017-05-01

    In this experiment, we developed and evaluated the Portland Arithmetic Stress Task (PAST) as a cognitive stressor to evaluate acute and sustained stress reactivity for event-related potential (ERP) studies. The PAST is a titrated arithmetic task adapted from the Montreal Imaging Stress Task (MIST), with added experimental control over presentation parameters, improved and synchronized acoustic feedback and generation of timing markers needed for physiological analyzes of real-time brain activity. Thirty-one older adults (M = 60 years) completed the PAST. EEG was recorded to assess feedback-related negativity (FRN) and the magnitude of the stress response through autonomic nervous system activity and salivary cortisol. Physiological measures other than EEG included heart rate, respiration rate, heart rate variability, blood pressure and salivary cortisol. These measures were collected at several time points throughout the task. Feedback-related negativity evoked-potential responses were elicited and they significantly differed depending on whether positive or negative feedback was received. The PAST also increased systolic blood pressure, heart rate variability and respiration rates compared to a control condition attentional task. These preliminary results suggest that the PAST is an effective cognitive stressor. Successful measurement of the feedback-related negativity suggests that the PAST is conducive to EEG and time-sensitive ERP experiments. Moreover, the physiological findings support the PAST as a potent method for inducing stress in older adult participants. Further research is needed to confirm these results, but the PAST shows promise as a tool for cognitive stress induction for time-locked event-related potential experiments.

  14. [Differential effects of attention deficit/hyperactivity disorder subtypes in event-related potentials].

    Science.gov (United States)

    Tamayo-Orrego, Lukas; Osorio Forero, Alejandro; Quintero Giraldo, Lina Paola; Parra Sánchez, José Hernán; Varela, Vilma; Restrepo, Francia

    2015-01-01

    To better understand the neurophysiological substrates in attention deficit/hyperactivity disorder (ADHD), a study was performed on of event-related potentials (ERPs) in Colombian patients with inattentive and combined ADHD. A case-control, cross-sectional study was designed. The sample was composed of 180 subjects between 5 and 15 years of age (mean, 9.25±2.6), from local schools in Manizales. The sample was divided equally in ADHD or control groups and the subjects were paired by age and gender. The diagnosis was made using the DSM-IV-TR criteria, the Conners and WISC-III test, a psychiatric interview (MINIKID), and a medical evaluation. ERPs were recorded in a visual and auditory passive oddball paradigm. Latency and amplitude of N100, N200 and P300 components for common and rare stimuli were used for statistical comparisons. ADHD subjects show differences in the N200 amplitude and P300 latency in the auditory task. The N200 amplitude was reduced in response to visual stimuli. ADHD subjects with combined symptoms show a delayed P300 in response to auditory stimuli, whereas inattentive subjects exhibited differences in the amplitude of N100 and N200. Combined ADHD patients showed longer N100 latency and smaller N200-P300 amplitude compared to inattentive ADHD subjects. The results show differences in the event-related potentials between combined and inattentive ADHD subjects. Copyright © 2014 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

  15. Adverse Health Events Related to Self-Medication Practices Among Elderly: A Systematic Review.

    Science.gov (United States)

    Locquet, Médéa; Honvo, Germain; Rabenda, Véronique; Van Hees, Thierry; Petermans, Jean; Reginster, Jean-Yves; Bruyère, Olivier

    2017-05-01

    Older adults often resort to self-medication to relieve symptoms of their current illnesses; however, the risks of this practice are multiplied in old age. In particular, this age group is more vulnerable to adverse drug events because of the physiological changes that occur due to senescence. The aim of the study was to obtain an overview of the adverse health events related to self-medication among subjects aged 60 years and over through a systematic review of the literature. A study of relevant articles was conducted among databases (MEDLINE, PsycINFO, and EBM Reviews-Cochrane Database of Systematic Reviews). Eligibility criteria were established and applied by two investigators to include suitable studies. The results and outcomes of interest were detailed in a descriptive report. The electronic search identified 4096 references, and the full texts of 74 were reviewed, of which four were retained in the analysis: three had a cross-sectional design and one prospectively followed elderly subjects. The first study showed a 26.7% prevalence of adverse drug reactions (ADRs) among elders, the second study found a 75% prevalence of side effects, and, finally, a prospective study showed an ADR incidence of 4.5% among self-medicated elders. These studies showed that adverse health events related to self-medication are relatively frequently reported. They also highlighted that analgesics and anti-inflammatory drugs are the most self-medicated products, while vitamins and dietary supplements also appear to be frequently self-administered, but by older individuals. Studies on self-medication in the elderly and its adverse health effects are clearly lacking. There is a need to perform prospective studies on this topic to gain a clear understanding of the extent of this problem and to enhance the awareness of health professionals to better inform seniors.

  16. Emotional Granularity Effects on Event-Related Brain Potentials during Affective Picture Processing

    Science.gov (United States)

    Lee, Ja Y.; Lindquist, Kristen A.; Nam, Chang S.

    2017-01-01

    There is debate about whether emotional granularity, the tendency to label emotions in a nuanced and specific manner, is merely a product of labeling abilities, or a systematic difference in the experience of emotion during emotionally evocative events. According to the Conceptual Act Theory of Emotion (CAT) (Barrett, 2006), emotional granularity is due to the latter and is a product of on-going temporal differences in how individuals categorize and thus make meaning of their affective states. To address this question, the present study investigated the effects of individual differences in emotional granularity on electroencephalography-based brain activity during the experience of emotion in response to affective images. Event-related potentials (ERP) and event-related desynchronization and synchronization (ERD/ERS) analysis techniques were used. We found that ERP responses during the very early (60–90 ms), middle (270–300 ms), and later (540–570 ms) moments of stimulus presentation were associated with individuals’ level of granularity. We also observed that highly granular individuals, compared to lowly granular individuals, exhibited relatively stable desynchronization of alpha power (8–12 Hz) and synchronization of gamma power (30–50 Hz) during the 3 s of stimulus presentation. Overall, our results suggest that emotional granularity is related to differences in neural processing throughout emotional experiences and that high granularity could be associated with access to executive control resources and a more habitual processing of affective stimuli, or a kind of “emotional complexity.” Implications for models of emotion are also discussed. PMID:28392761

  17. P300 event-related potential in abstinent methamphetamine-dependent patients.

    Science.gov (United States)

    Haifeng, Jiang; Wenxu, Zhuang; Hong, Cheng; Chuanwei, Li; Jiang, Du; Haiming, Sun; Zhikang, Chen; Din, Xu; Jijun, Wang; Min, Zhao

    2015-10-01

    Substance use and abuse are characterized by biases in the attentional processing of substance-related stimuli. There are no event related potential (ERP)-based studies of attentional bias for substance-related cues among methamphetamine (MA) dependent patients. The study aimed to measure changes in P300 event-related potentials elicited by MA-related words in MA-dependent individuals at baseline and after 3 and 6 months of abstinence, examining the relationship of ERP changes to craving. 26 MA-dependent patients (14 male) newly enrolled in two compulsory treatment centers in China and 29 healthy controls (15 male) were included in this study. At baseline (2-3 weeks in treatment) and after 3 and 6 months of abstinence from MA use, we obtained ERP data during a Stroop color-matching task using MA-related and neutral words. Self-reported craving was measured by a Visual Analog Scale (VAS). Increased P300 amplitudes elicited by MA-related words were observed over left-anterior electrode sites. Abnormal P300 amplitudes declined to the normal levels of healthy controls at the end of 3 months of abstinence, and the decrease was maintained up to the end of 6 months of abstinence. The behavioral data did not show similar changes. The positive relationship between the changes of VAS scores for MA craving and the changes of P300 amplitudes over left anterior electrode sites elicited by MA-related words within the first 3 months was significant. These findings highlight the potential use of ERP as an objective index to track changes in subjective MA craving among abstinent MA-dependent patients. Copyright © 2015. Published by Elsevier Inc.

  18. Resilience to traumatic events related to urban violence and increased IL10 serum levels.

    Science.gov (United States)

    Teche, Stefania P; Rovaris, Diego L; Aguiar, Bianca W; Hauck, Simone; Vitola, Eduardo S; Bau, Claiton H D; Freitas, Lucia H; Grevet, Eugenio H

    2017-04-01

    The exposition to traumatic events related to urban violence is epidemic in Brazil, with rate of 80% in the general population, and is becoming a major cause of post-traumatic stress disorder (PTSD). The objective of the study was to compare serum levels of pro-inflammatory interleukin-6 (IL-6) and anti-inflammatory interleukin-10 (IL-10) in PTSD and resilient individuals. We hypothesized that resilient individuals present an attenuated pro-inflammatory and enhanced anti-inflammatory state. We conducted a case-control study comparing 30 resilient individuals and 30 PTSD patients exposed to traumatic events related to urban violence. The groups were evaluated using Self-Report Questionnaire (SRQ-20), Mini-International Neuropsychiatric Interview (MINI) and the Davidson Trauma Scale. For all individuals, blood samples were collected to determine IL-6, IL-10 and cortisol serum levels. All samples were frozen at -80°C until the assay and were analyzed with the same immunoassay kit and in duplicates. The resilient group presented higher IL-10 levels than PTSD patients [mean (CI95%); 1.03 (0.52-2.08) pg/mL vs. 0.29 (0.20-0.43) pg/mL; P=0.002]. There were no differences in terms of IL-6 or cortisol levels. The results provided evidence for increased levels of IL-10 in resilient individuals when compared to PTSD patients, probably conferring them a better anti-inflammatory response after exposition. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

  19. Probing the transformation of discontinuous associations into episodic memory: an event-related fMRI study.

    NARCIS (Netherlands)

    Qin, S.; Piekema, C.; Petersson, K.M.; Han, B.; Luo, J.; Fernandez, G.

    2007-01-01

    Using event-related functional magnetic resonance imaging, we identified brain regions involved in storing associations of events discontinuous in time into long-term memory. Participants were scanned while memorizing item-triplets including simultaneous and discontinuous associations. Subsequent

  20. U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center-Fiscal Year 2009 Annual Report

    Science.gov (United States)

    Nelson, Janice S.

    2010-01-01

    The Earth Resources Observation and Science (EROS) Center is a U.S. Geological Survey (USGS) facility focused on providing science and imagery to better understand our Earth. As part of the USGS Geography Discipline, EROS contributes to the Land Remote Sensing (LRS) Program, the Geographic Analysis and Monitoring (GAM) Program, and the National Geospatial Program (NGP), as well as our Federal partners and cooperators. The work of the Center is shaped by the Earth sciences, the missions of our stakeholders, and implemented through strong program and project management and application of state-of-the-art information technologies. Fundamentally, EROS contributes to the understanding of a changing Earth through 'research to operations' activities that include developing, implementing, and operating remote sensing based terrestrial monitoring capabilities needed to address interdisciplinary science and applications objectives at all levels-both nationally and internationally. The Center's programs and projects continually strive to meet and/or exceed the changing needs of the USGS, the Department of the Interior, our Nation, and international constituents. The Center's multidisciplinary staff uses their unique expertise in remote sensing science and technologies to conduct basic and applied research, data acquisition, systems engineering, information access and management, and archive preservation to address the Nation's most critical needs. Of particular note is the role of EROS as the primary provider of Landsat data, the longest comprehensive global land Earth observation record ever collected. This report is intended to provide an overview of the scientific and engineering achievements and illustrate the range and scope of the activities and accomplishments at EROS throughout fiscal year (FY) 2009. Additional information concerning the scientific, engineering, and operational achievements can be obtained from the scientific papers and other documents published by

  1. Event-related potential measures of a violation of an expected increase and decrease in intensity.

    Science.gov (United States)

    Macdonald, Margaret; Campbell, Kenneth

    2013-01-01

    Unexpected physical increases in the intensity of a frequently occurring "standard" auditory stimulus are experienced as obtrusive. This could either be because of a physical change, the increase in intensity of the "deviant" stimulus, or a psychological change, the violation of the expectancy for the occurrence of the lower intensity standard stimulus. Two experiments were run in which event-related potentials (ERPs) were recorded to determine whether "psychological" increments (violation of an expectancy for a lower intensity) would be processed differently than psychological decrements (violation of an expectancy for a higher intensity). Event-related potentials (ERPs) were recorded while subjects were presented with auditory tones that alternated between low and high intensity. The subjects ignored the auditory stimuli while watching a video. Deviants were created by repeating the same stimulus. In the first experiment, pairs of stimuli alternating in intensity, were presented in separate increment (H-L...H-L...H-H...H-L, in which H = 80 dB SPL and L = 60 dB SPL) and decrement conditions (L-H...L-H...L-L... L-H, in which H = 90 dB SPL and L = 80 dB SPL). The paradigm employed in the second experiment consisted of an alternating intensity pattern (H-L-H-L-H-H-H-L) or (H-L-H-L-L-L-H-L). Importantly, the stimulus prior to the deviant (the standard) and the actual deviants in both increment and decrement conditions in both experiments were physically identical (80 dB SPL tones). The repetition of the lower intensity tone therefore acted as a psychological rather than a physical decrement (a higher intensity tone was expected) while the repetition of the higher intensity tone acted as a psychological increment (a lower intensity tone was expected). The psychological increments in both experiments elicited a larger amplitude mismatch negativity (MMN) than the decrements. Thus, regardless of whether an acoustic change signals a physical increase in intensity or

  2. Efectos de la hipoxia en montañeros expuestos a altitudes extremas

    Directory of Open Access Journals (Sweden)

    Javier Aceña Medina

    2017-03-01

    Full Text Available La práctica del montañismo goza en la actualidad de una gran popularidad entre nuestros deportistas. Los montañeros que se mueven en grandes altitudes se ven expuestos frecuentemente a climatologías muy adversas y vías de gran dificultad física y técnica, pero posiblemente el enemigo más temible al que se tienen que enfrentar tiene que ver con los indeseables efectos de la hipoxia. La presente investigación se centra en constatar posibles deterioros en las habilidades del pensamiento de un grupo de montañeros expuesto a altitudes extremas (por encima de los 5.500 metros, sin ayuda de oxígeno suplementario. Para ello hemos contado con la participación de montañeros de tres expediciones a los “ochomiles” Manaslu, Makalu y Gasherbrum II a los que se aplicaron pruebas de aptitudes mentales antes, durante y después de cada expedición. La singularidad de nuestro estudio reside en haber incorporado resultados de pruebas realizadas en altitudes extremas, en concreto a 5.800, 6.200 y 6.000 metros respectivamente. Los resultados ponen de manifiesto que de todas las áreas y funciones cognitivas evaluadas, parece ser que las más afectadas por los efectos de la hipoxia han sido las relacionadas con la capacidad de razonamiento abstracto, espacial y verbal. Los deterioros más evidentes se observaron en altitud, persistiendo estos a la semana de regresar. Tras seis meses dichos déficits se recuperaron por completo.

  3. Eros thanático en Paradiso de José Lezama Lima

    Directory of Open Access Journals (Sweden)

    Edinson Aladino

    2017-08-01

    Full Text Available Los personajes en la novelística de José Lezama Lima no son simples tipologías que devienen bajo la estructura del lenguaje. Los personajes lezamianos son su circunstancia atravesada por la alineación de un destino noble o aciago. Eugenio Foción encara en Paradiso la circunstancia de un destino aciago, arquetipo fundamental en el decurso de la novela que viene a representar la fijeza del deseo como fragmentación de vida. Querencia de muerte o Eros thanático que rodea al corazón del cuerpo para impeler su pulsión vital.

  4. Enfoque Fisioterápico del dolor inguinal del montañero

    OpenAIRE

    Caudevilla Polo, Santos; Rubio Ibarzo, Sara; Lucha López, Orosia; Tricás Moreno, José Miguel; Estébanez de Miguel, Elena; Hidalgo García, César

    2002-01-01

    En este artículo se ha realizado un enfoque fisioterapéutico del dolor inguinal del montañero. El dolor inguinal es un problema frecuente y clínicamente complejo en un gran número de deportes. Existen multitud de causas que pueden generar este dolor, pero en este artículo sólo se muestra lo relacionado con la disfunción de la articulación de la cadera y sus músculos. Los estudios de Kaltenborn-Evjenth, Sohier, Ekman, Butler y Chaitow ofrecen información novedosa para el tratamiento d...

  5. The Cognition of Priapo. Caricature procedures in Carlo Emilio Gadda’s Eros e Priapo.

    Directory of Open Access Journals (Sweden)

    Paolo Gervasi

    2017-01-01

    As several neuroscientific researches demonstrated, from a cognitive perspective caricature can be considered as a tool for the comprehension of the world. The human mind selects, shapes and emphasises elements in order to detect patterns in the muddle of perceptions. For the human mind misshaping the world means to uncover its hidden features, which would remain unexpressed if not stressed. Similarly, as demonstrated by Eros e Priapo, caricature is a critical device, isolating and emphasising details to upset schemes, while revealing the psychological deformations produced by historical events.

  6. Anders Nygrenin lundilainen ja luterilainen rakkaudenteologia teoksessa Eros och Agape I

    OpenAIRE

    Hiltunen, Mikko

    2016-01-01

    Tämän tutkielman tavoitteena oli selvittää, miten Anders Nygrenin taustalla vaikuttavat fundamentaalisteologiset taustaoletukset ja hänen käyttämänsä metodi vaikuttaa niihin johtopäätöksiin, joihin hän päätyy teoksessaan Eros och Agape I. Nygrenin tutkimuksen on sanottu olevan 1900-luvun merkittävin tutkimus rakkaudesta. Nygrenin tutkimus nosti rakkauden kansainvälisesti kiinnostavaksi tutkimuksen kohteeksi. Kiinnostus ylitti tieteenalan rajat. Harvat Nygrenin jälkeisistä tutkimuksista asettu...

  7. Effects of negative content on the processing of gender information: an event-related potential study.

    Science.gov (United States)

    Hinojosa, José A; Albert, Jacobo; Fernández-Folgueiras, Uxía; Santaniello, Gerardo; López-Bachiller, Cristina; Sebastián, Manuel; Sánchez-Carmona, Alberto J; Pozo, Miguel A

    2014-12-01

    Previous research on emotion in language has mainly concerned the impact of emotional information on several aspects of lexico-semantic analyses of single words. However, affective influences on morphosyntactic processing are less understood. In the present study, we focused on the impact of negative valence in the processing of gender agreement relations. Event-related potentials (ERPs) were recorded while participants read three-word phrases and performed a syntactic judgment task. Negative and neutral adjectives could agree or disagree in gender with the preceding noun. At an electrophysiological level, the amplitude of a left anterior negativity (LAN) to gender agreement mismatches decreased in negative words, relative to neutral words. The behavioral data suggested that LAN amplitudes might be indexing the processing costs associated with the detection of gender agreement errors, since the detection of gender mismatches resulted in faster and more accurate responses than did the detection of correct gender agreement relations. According to this view, it seems that negative content facilitated the processes implicated in the early detection of gender agreement mismatches. However, gender agreement violations in negative words triggered processes involved in the reanalysis and repair of the syntactic structure, as reflected in larger P600 amplitudes to incorrect than to correct phrases, irrespective of their emotional valence.

  8. An event-related potential study of selective auditory attention in children and adults.

    Science.gov (United States)

    Coch, Donna; Sanders, Lisa D; Neville, Helen J

    2005-04-01

    In a dichotic listening paradigm, event-related potentials (ERPs) were recorded to linguistic and nonlinguistic probe stimuli embedded in 2 different narrative contexts as they were either attended or unattended. In adults, the typical N1 attention effect was observed for both types of probes: Probes superimposed on the attended narrative elicited an enhanced negativity compared to the same probes when unattended. Overall, this sustained attention effect was greater over medial and left lateral sites, but was more posteriorly distributed and of longer duration for linguistic as compared to nonlinguistic probes. In contrast, in 6- to 8-year-old children the ERPs were morphologically dissimilar to those elicited in adults and children displayed a greater positivity to both types of probe stimuli when embedded in the attended as compared to the unattended narrative. Although both adults and children showed attention effects beginning at about 100 msec, only adults displayed left-lateralized attention effects and a distinct, posterior distribution for linguistic probes. These results suggest that the attentional networks indexed by this task continue to develop beyond the age of 8 years.

  9. A periodic spatio-spectral filter for event-related potentials.

    Science.gov (United States)

    Ghaderi, Foad; Kim, Su Kyoung; Kirchner, Elsa Andrea

    2016-12-01

    With respect to single trial detection of event-related potentials (ERPs), spatial and spectral filters are two of the most commonly used pre-processing techniques for signal enhancement. Spatial filters reduce the dimensionality of the data while suppressing the noise contribution and spectral filters attenuate frequency components that most likely belong to noise subspace. However, the frequency spectrum of ERPs overlap with that of the ongoing electroencephalogram (EEG) and different types of artifacts. Therefore, proper selection of the spectral filter cutoffs is not a trivial task. In this research work, we developed a supervised method to estimate the spatial and finite impulse response (FIR) spectral filters, simultaneously. We evaluated the performance of the method on offline single trial classification of ERPs in datasets recorded during an oddball paradigm. The proposed spatio-spectral filter improved the overall single-trial classification performance by almost 9% on average compared with the case that no spatial filters were used. We also analyzed the effects of different spectral filter lengths and the number of retained channels after spatial filtering. Copyright © 2016. Published by Elsevier Ltd.

  10. Subject Combination and Electrode Selection in Cooperative Brain-Computer Interface Based on Event Related Potentials

    Directory of Open Access Journals (Sweden)

    Hubert Cecotti

    2014-04-01

    Full Text Available New paradigms are required in Brain-Computer Interface (BCI systems for the needs and expectations of healthy people. To solve this issue, we explore the emerging field of cooperative BCIs, which involves several users in a single BCI system. Contrary to classical BCIs that are dependent on the unique subject’s will, cooperative BCIs are used for problem solving tasks where several people shall be engaged by sharing a common goal. Similarly as combining trials over time improves performance, combining trials across subjects can significantly improve performance compared with when only a single user is involved. Yet, cooperative BCIs may only be used in particular settings, and new paradigms must be proposed to efficiently use this approach. The possible benefits of using several subjects are addressed, and compared with current single-subject BCI paradigms. To show the advantages of a cooperative BCI, we evaluate the performance of combining decisions across subjects with data from an event-related potentials (ERP based experiment where each subject observed the same sequence of visual stimuli. Furthermore, we show that it is possible to achieve a mean AUC superior to 0.95 with 10 subjects and 3 electrodes on each subject, or with 4 subjects and 6 electrodes on each subject. Several emerging challenges and possible applications are proposed to highlight how cooperative BCIs could be efficiently used with current technologies and leverage BCI applications.

  11. Aesthetic appreciation of poetry correlates with ease of processing in event-related potentials.

    Science.gov (United States)

    Obermeier, Christian; Kotz, Sonja A; Jessen, Sarah; Raettig, Tim; von Koppenfels, Martin; Menninghaus, Winfried

    2016-04-01

    Rhetorical theory suggests that rhythmic and metrical features of language substantially contribute to persuading, moving, and pleasing an audience. A potential explanation of these effects is offered by "cognitive fluency theory," which stipulates that recurring patterns (e.g., meter) enhance perceptual fluency and can lead to greater aesthetic appreciation. In this article, we explore these two assertions by investigating the effects of meter and rhyme in the reception of poetry by means of event-related brain potentials (ERPs). Participants listened to four versions of lyrical stanzas that varied in terms of meter and rhyme, and rated the stanzas for rhythmicity and aesthetic liking. The behavioral and ERP results were in accord with enhanced liking and rhythmicity ratings for metered and rhyming stanzas. The metered and rhyming stanzas elicited smaller N400/P600 ERP responses than their nonmetered, nonrhyming, or nonmetered and nonrhyming counterparts. In addition, the N400 and P600 effects for the lyrical stanzas correlated with aesthetic liking effects (metered-nonmetered), implying that modulation of the N400 and P600 has a direct bearing on the aesthetic appreciation of lyrical stanzas. We suggest that these effects are indicative of perceptual-fluency-enhanced aesthetic liking, as postulated by cognitive fluency theory.

  12. Clinical Experiments of Communication by ALS Patient Utilizing Detecting Event-Related Potential

    Science.gov (United States)

    Kanou, Naoyuki; Sakuma, Kenji; Nakashima, Kenji

    Amyotrophic Lateral Sclerosis(ALS) patients are unable to successfully communicate their desires, although their mentality is normal, and so, the necessity of Communication Aids(CA) for ALS patients is realized. Therefore, the authors are focused on Event-Related Potential(ERP) which is elicited primarily for the target by visual and auditory stimuli. P200, N200 and P300 are components of ERP. These are potentials that are elicited when the subject focuses attention on stimuli that appears infrequently. ALS patient participated in two experiments. In the first experiment, a target word out of five words on a computer display was specified. The five words were linked to an each electric appliance, allowing the ALS patient to switch on a target appliance by ERP. In the second experiment, a target word in a 5×5 matrix was specified by measure of ERP. The rows and columns of the matrix were reversed randomly. The word on a crossing point of rows and columns including the target word, was specified as the target word. The rate of correct judgment in the first and second experiments were 100% in N200 and 96% in P200. For practical use of this system, it is very important to determine suitable communication algorithms for each patient by performing these experiments evaluating the results.

  13. Event-related potentials during word mapping to object shape predict toddlers' vocabulary size

    Science.gov (United States)

    Borgström, Kristina; Torkildsen, Janne von Koss; Lindgren, Magnus

    2015-01-01

    What role does attention to different object properties play in early vocabulary development? This longitudinal study using event-related potentials in combination with behavioral measures investigated 20- and 24-month-olds' (n = 38; n = 34; overlapping n = 24) ability to use object shape and object part information in word-object mapping. The N400 component was used to measure semantic priming by images containing shape or detail information. At 20 months, the N400 to words primed by object shape varied in topography and amplitude depending on vocabulary size, and these differences predicted productive vocabulary size at 24 months. At 24 months, when most of the children had vocabularies of several hundred words, the relation between vocabulary size and the N400 effect in a shape context was weaker. Detached object parts did not function as word primes regardless of age or vocabulary size, although the part-objects were identified behaviorally. The behavioral measure, however, also showed relatively poor recognition of the part-objects compared to the shape-objects. These three findings provide new support for the link between shape recognition and early vocabulary development. PMID:25762957

  14. From mind to mouth: event related potentials of sentence production in classic galactosemia.

    Directory of Open Access Journals (Sweden)

    Inge Timmers

    Full Text Available Patients with classic galactosemia, an inborn error of metabolism, have speech and language production impairments. Past research primarily focused on speech (motor problems, but these cannot solely explain the language impairments. Which specific deficits contribute to the impairments in language production is not yet known. Deficits in semantic and syntactic planning are plausible and require further investigation. In the present study, we examined syntactic encoding while patients and matched controls overtly described scenes of moving objects using either separate words (minimal syntactic planning or sentences (sentence-level syntactic planning. The design of the paradigm also allowed tapping into local noun phrase- and more global sentence-level syntactic planning. Simultaneously, we recorded event-related potentials (ERPs. The patients needed more time to prepare and finish the utterances and made more errors. The patient ERPs had a very similar morphology to that of healthy controls, indicating overall comparable neural processing. Most importantly, the ERPs diverged from those of controls in several functionally informative time windows, ranging from very early (90-150 ms post scene onset to relatively late (1820-2020 ms post scene onset. These time windows can be associated with different linguistic encoding stages. The ERP results form the first neuroscientific evidence for language production impairments in patients with galactosemia in lexical and syntactic planning stages, i.e., prior to the linguistic output phase. These findings hence shed new light on the language impairments in this disease.

  15. From mind to mouth: event related potentials of sentence production in classic galactosemia.

    Science.gov (United States)

    Timmers, Inge; Jansma, Bernadette M; Rubio-Gozalbo, M Estela

    2012-01-01

    Patients with classic galactosemia, an inborn error of metabolism, have speech and language production impairments. Past research primarily focused on speech (motor) problems, but these cannot solely explain the language impairments. Which specific deficits contribute to the impairments in language production is not yet known. Deficits in semantic and syntactic planning are plausible and require further investigation. In the present study, we examined syntactic encoding while patients and matched controls overtly described scenes of moving objects using either separate words (minimal syntactic planning) or sentences (sentence-level syntactic planning). The design of the paradigm also allowed tapping into local noun phrase- and more global sentence-level syntactic planning. Simultaneously, we recorded event-related potentials (ERPs). The patients needed more time to prepare and finish the utterances and made more errors. The patient ERPs had a very similar morphology to that of healthy controls, indicating overall comparable neural processing. Most importantly, the ERPs diverged from those of controls in several functionally informative time windows, ranging from very early (90-150 ms post scene onset) to relatively late (1820-2020 ms post scene onset). These time windows can be associated with different linguistic encoding stages. The ERP results form the first neuroscientific evidence for language production impairments in patients with galactosemia in lexical and syntactic planning stages, i.e., prior to the linguistic output phase. These findings hence shed new light on the language impairments in this disease.

  16. Time-Frequency Data Reduction for Event Related Potentials: Combining Principal Component Analysis and Matching Pursuit

    Directory of Open Access Journals (Sweden)

    Selin Aviyente

    2010-01-01

    Full Text Available Joint time-frequency representations offer a rich representation of event related potentials (ERPs that cannot be obtained through individual time or frequency domain analysis. This representation, however, comes at the expense of increased data volume and the difficulty of interpreting the resulting representations. Therefore, methods that can reduce the large amount of time-frequency data to experimentally relevant components are essential. In this paper, we present a method that reduces the large volume of ERP time-frequency data into a few significant time-frequency parameters. The proposed method is based on applying the widely used matching pursuit (MP approach, with a Gabor dictionary, to principal components extracted from the time-frequency domain. The proposed PCA-Gabor decomposition is compared with other time-frequency data reduction methods such as the time-frequency PCA approach alone and standard matching pursuit methods using a Gabor dictionary for both simulated and biological data. The results show that the proposed PCA-Gabor approach performs better than either the PCA alone or the standard MP data reduction methods, by using the smallest amount of ERP data variance to produce the strongest statistical separation between experimental conditions.

  17. Event-related potentials elicited by social commerce and electronic-commerce reviews.

    Science.gov (United States)

    Bai, Yan; Yao, Zhong; Cong, Fengyu; Zhang, Linlin

    2015-12-01

    There is an increasing interest regarding the use of electroencephalography (EEG) in social commerce and electronic commerce (e-commerce) research. There are several reviews in the field of social commerce or e-commerce; these have great potential value and mining them is fundamental and significant. To our knowledge, EEG is rarely applied to study these. In this study, we examined the neural correlates of social commerce reviews (SCRs) and e-commerce reviews (ECRs) by using them as stimuli to evoke event-related potentials. All SCRs were from friends through a social media platform, whereas ECRs were from strangers through an e-commerce platform. The experimental design was similar to that of a priming paradigm, and included 40 pairs of stimuli consisting of product information (prime stimulus) and reviews (target stimulus). The results showed that the P300 component was successfully evoked by SCR and ECR stimuli. Moreover, the P300 components elicited by SCRs had higher amplitudes than those elicited by ECRs. These findings indicate that participants paid more attention to SCRs than to ECRs. In addition, the associations between neural responses and reviews in social commerce have the potential to assist companies in studying consumer behaviors, thus permitting them to enhance their social commerce strategies.

  18. Gender and number processing in Chinese learners of Spanish - evidence from Event Related Potentials.

    Science.gov (United States)

    Dowens, Margaret Gillon; Guo, Taomei; Guo, Jingjing; Barber, Horacio; Carreiras, Manuel

    2011-06-01

    Traditionally, age of acquisition (AoA) has been considered the single most important factor in second language (L2) acquisition and processing, particularly in the area of syntax processing. However, there is now growing evidence of the importance of other factors, such as the level of proficiency attained and the degree of overlap or similarity between the first language (L1) and L2 structures and possibility of transfer of features and/or processing routines. However, the relative importance of these factors and the nature of L1-L2 transfer are still unclear. To shed light on these issues, we recorded the electrical brain activity of a group of Chinese proficient late learners of Spanish, using the Event Related Potentials technique, while they read Spanish sentences containing violations of number and grammatical gender agreement (adjective-noun agreement and article-noun agreement). Unlike Spanish, Mandarin Chinese is an isolating language in which morphosyntactic features such as gender and number are not computed and so the ERP results from this group can help to clarify the role of L1-L2 transfer in morpho-syntax processing routines. The results included P600 effects for both gender and number agreement violations, with no differences between these disagreement conditions. These results are taken to support second language acquisition models which stress the roles of proficiency and L1-L2 transfer in L2 syntax processing. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. How culture gets embrained: Cultural differences in event-related potentials of social norm violations.

    Science.gov (United States)

    Mu, Yan; Kitayama, Shinobu; Han, Shihui; Gelfand, Michele J

    2015-12-15

    Humans are unique among all species in their ability to develop and enforce social norms, but there is wide variation in the strength of social norms across human societies. Despite this fundamental aspect of human nature, there has been surprisingly little research on how social norm violations are detected at the neurobiological level. Building on the emerging field of cultural neuroscience, we combine noninvasive electroencephalography (EEG) with a new social norm violation paradigm to examine the neural mechanisms underlying the detection of norm violations and how they vary across cultures. EEG recordings from Chinese and US participants (n = 50) showed consistent negative deflection of event-related potential around 400 ms (N400) over the central and parietal regions that served as a culture-general neural marker of detecting norm violations. The N400 at the frontal and temporal regions, however, was only observed among Chinese but not US participants, illustrating culture-specific neural substrates of the detection of norm violations. Further, the frontal N400 predicted a variety of behavioral and attitudinal measurements related to the strength of social norms that have been found at the national and state levels, including higher culture superiority and self-control but lower creativity. There were no cultural differences in the N400 induced by semantic violation, suggesting a unique cultural influence on social norm violation detection. In all, these findings provided the first evidence, to our knowledge, for the neurobiological foundations of social norm violation detection and its variation across cultures.

  20. Neurophysiological Effects of Meditation Based on Evoked and Event Related Potential Recordings

    Science.gov (United States)

    Singh, Nilkamal; Telles, Shirley

    2015-01-01

    Evoked potentials (EPs) are a relatively noninvasive method to assess the integrity of sensory pathways. As the neural generators for most of the components are relatively well worked out, EPs have been used to understand the changes occurring during meditation. Event-related potentials (ERPs) yield useful information about the response to tasks, usually assessing attention. A brief review of the literature yielded eleven studies on EPs and seventeen on ERPs from 1978 to 2014. The EP studies covered short, mid, and long latency EPs, using both auditory and visual modalities. ERP studies reported the effects of meditation on tasks such as the auditory oddball paradigm, the attentional blink task, mismatched negativity, and affective picture viewing among others. Both EP and ERPs were recorded in several meditations detailed in the review. Maximum changes occurred in mid latency (auditory) EPs suggesting that maximum changes occur in the corresponding neural generators in the thalamus, thalamic radiations, and primary auditory cortical areas. ERP studies showed meditation can increase attention and enhance efficiency of brain resource allocation with greater emotional control. PMID:26137479

  1. Early event-related potential effects of syllabic processing during visual word recognition.

    Science.gov (United States)

    Carreiras, Manuel; Vergara, Marta; Barber, Horacio

    2005-11-01

    A number of behavioral studies have suggested that syllables might play an important role in visual word recognition in some languages. We report two event-related potential (ERP) experiments using a new paradigm showing that syllabic units modulate early ERP components. In Experiment 1, words and pseudowords were presented visually and colored so that there was a match or a mismatch between the syllable boundaries and the color boundaries. The results showed color-syllable congruency effects in the time window of the P200. Lexicality modulated the N400 amplitude, but no effects of this variable were obtained at the P200 window. In Experiment 2, high- and low-frequency words and pseudowords were presented in the congruent and incongruent conditions. The results again showed congruency effects at the P200 for low-frequency words and pseudowords, but not for high-frequency words. Lexicality and lexical frequency effects showed up at the N400 component. The results suggest a dissociation between syllabic and lexical effects with important consequences for models of visual word recognition.

  2. Causality in the association between P300 and alpha event-related desynchronization.

    Directory of Open Access Journals (Sweden)

    Weiwei Peng

    Full Text Available Recent findings indicated that both P300 and alpha event-related desynchronization (α-ERD were associated, and similarly involved in cognitive brain functioning, e.g., attention allocation and memory updating. However, an explicit causal influence between the neural generators of P300 and α-ERD has not yet been investigated. In the present study, using an oddball task paradigm, we assessed the task effect (target vs. non-target on P300 and α-ERD elicited by stimuli of four sensory modalities, i.e., audition, vision, somatosensory, and pain, estimated their respective neural generators, and investigated the information flow among their neural generators using time-varying effective connectivity in the target condition. Across sensory modalities, the scalp topographies of P300 and α-ERD were similar and respectively maximal at parietal and occipital regions in the target condition. Source analysis revealed that P300 and α-ERD were mainly generated from posterior cingulate cortex and occipital lobe respectively. As revealed by time-varying effective connectivity, the cortical information was consistently flowed from α-ERD sources to P300 sources in the target condition for all four sensory modalities. All these findings showed that P300 in the target condition is modulated by the changes of α-ERD, which would be useful to explore neural mechanism of cognitive information processing in the human brain.

  3. Inverse effectiveness and multisensory interactions in visual event-related potentials with audiovisual speech.

    Science.gov (United States)

    Stevenson, Ryan A; Bushmakin, Maxim; Kim, Sunah; Wallace, Mark T; Puce, Aina; James, Thomas W

    2012-07-01

    In recent years, it has become evident that neural responses previously considered to be unisensory can be modulated by sensory input from other modalities. In this regard, visual neural activity elicited to viewing a face is strongly influenced by concurrent incoming auditory information, particularly speech. Here, we applied an additive-factors paradigm aimed at quantifying the impact that auditory speech has on visual event-related potentials (ERPs) elicited to visual speech. These multisensory interactions were measured across parametrically varied stimulus salience, quantified in terms of signal to noise, to provide novel insights into the neural mechanisms of audiovisual speech perception. First, we measured a monotonic increase of the amplitude of the visual P1-N1-P2 ERP complex during a spoken-word recognition task with increases in stimulus salience. ERP component amplitudes varied directly with stimulus salience for visual, audiovisual, and summed unisensory recordings. Second, we measured changes in multisensory gain across salience levels. During audiovisual speech, the P1 and P1-N1 components exhibited less multisensory gain relative to the summed unisensory components with reduced salience, while N1-P2 amplitude exhibited greater multisensory gain as salience was reduced, consistent with the principle of inverse effectiveness. The amplitude interactions were correlated with behavioral measures of multisensory gain across salience levels as measured by response times, suggesting that change in multisensory gain associated with unisensory salience modulations reflects an increased efficiency of visual speech processing.

  4. Event-Related Potentials Reflect Speech-Relevant Somatosensory-Auditory Interactions

    Directory of Open Access Journals (Sweden)

    Takayuki Ito

    2011-10-01

    Full Text Available An interaction between orofacial somatosensation and the perception of speech was demonstrated in recent psychophysical studies (Ito et al. 2009; Ito and Ostry 2009. To explore further the neural mechanisms of the speech-related somatosensory-auditory interaction, we assessed to what extent multisensory evoked potentials reflect multisensory interaction during speech perception. We also examined the dynamic modulation of multisensory integration resulting from relative timing differences between the onsets of the two sensory stimuli. We recorded event-related potentials from 64 scalp sites in response to somatosensory stimulation alone, auditory stimulation alone, and combined somatosensory and auditory stimulation. In the multisensory condition, the timing of the two stimuli was either simultaneous or offset by 90 ms (lead and lag. We found evidence of multisensory interaction with the amplitude of the multisensory evoked potential reliably different than the sum of the two unisensory potentials around the first peak of multisensory response (100–200 ms. The magnitude of the evoked potential difference varied as a function of the relative timing between the stimuli in the interval from 170 to 200 ms following somatosensory stimulation. The results demonstrate clear multisensory convergence and suggest a dynamic modulation of multisensory interaction during speech.

  5. Encoding focus alters diagnostic recollection and event-related potentials (ERPs).

    Science.gov (United States)

    Leynes, P Andrew; Mok, Brittany A

    2017-10-01

    The influence of encoding focus on source memory was investigated using event-related potentials (ERPs). Encoding was focused on the self (self-focus) or on the speaker (other-focus) while hearing words spoken in a male or female voice. Examination of the behavioral and ERP evidence suggests that encoding focus alters the amount of diagnostic recollection. Self-focus encoding produced more positive encoding ERPs, led to greater old/new recognition, and elicited a greater Late Positive Component (LPC; the putative neural correlate of recollection) during the source test. Other-focus encoding led to greater source memory and a smaller LPC amplitude. Collectively, the results suggest that encoding focus alters the information bound in the memory trace that leads to varying levels of source-diagnostic features. Drawing attention to the speaker facilitates binding of source-diagnostic features (i.e., voice), whereas self-focus encoding facilitates binding a host of non-diagnostic features. The results have important implications for situations that depend on encoding processes, such as false memory or classroom learning, and they provide evidence that the LPC tracks recollected details but not necessarily diagnostic recollection. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Topic structure affects semantic integration: evidence from event-related potentials.

    Science.gov (United States)

    Yang, Xiaohong; Chen, Xuhai; Chen, Shuang; Xu, Xiaoying; Yang, Yufang

    2013-01-01

    This study investigated whether semantic integration in discourse context could be influenced by topic structure using event-related brain potentials. Participants read discourses in which the last sentence contained a critical word that was either congruent or incongruent with the topic established in the first sentence. The intervening sentences between the first and the last sentence of the discourse either maintained or shifted the original topic. Results showed that incongruent words in topic-maintained discourses elicited an N400 effect that was broadly distributed over the scalp while those in topic-shifted discourses elicited an N400 effect that was lateralized to the right hemisphere and localized over central and posterior areas. Moreover, a late positivity effect was only elicited by incongruent words in topic-shifted discourses, but not in topic-maintained discourses. This suggests an important role for discourse structure in semantic integration, such that compared with topic-maintained discourses, the complexity of discourse structure in topic-shifted condition reduces the initial stage of semantic integration and enhances the later stage in which a mental representation is updated.

  7. Event-related potentials reveal the relations between feature representations at different levels of abstraction.

    Science.gov (United States)

    Hannah, Samuel D; Shedden, Judith M; Brooks, Lee R; Grundy, John G

    2016-11-01

    In this paper, we use behavioural methods and event-related potentials (ERPs) to explore the relations between informational and instantiated features, as well as the relation between feature abstraction and rule type. Participants are trained to categorize two species of fictitious animals and then identify perceptually novel exemplars. Critically, two groups are given a perfectly predictive counting rule that, according to Hannah and Brooks (2009. Featuring familiarity: How a familiar feature instantiation influences categorization. Canadian Journal of Experimental Psychology/Revue Canadienne de Psychologie Expérimentale, 63, 263-275. Retrieved from http://doi.org/10.1037/a0017919), should orient them to using abstract informational features when categorizing the novel transfer items. A third group is taught a feature list rule, which should orient them to using detailed instantiated features. One counting-rule group were taught their rule before any exposure to the actual stimuli, and the other immediately after training, having learned the instantiations first. The feature-list group were also taught their rule after training. The ERP results suggest that at test, the two counting-rule groups processed items differently, despite their identical rule. This not only supports the distinction that informational and instantiated features are qualitatively different feature representations, but also implies that rules can readily operate over concrete inputs, in contradiction to traditional approaches that assume that rules necessarily act on abstract inputs.

  8. Independent component analysis applied to the P600 component of event-related potentials.

    Science.gov (United States)

    Ventouras, E; Moatsos, M; Papageorgiou, C; Rabavilas, A; Uzunoglu, N

    2004-01-01

    The analysis of the P600 component of Event-related Potentials (ERPs) has attracted attention due to its relation to covert cognitive mechanisms, in connection to memory processes. The component may often be low-amplitude, compared to other components such as the P300. Independent component analysis (ICA) techniques have been successfully applied in ERP processing, in the framework of blind source separation (BSS) for unmixing recorded potentials into a sum of temporally independent and spatially fixed components. In the present work ICA was used for reconstructing averaged ERPs in the time window of the P600 component, selecting a subset of independent components' projections to the original electrode recording positions. The selection is based on two empirical criteria, selecting the projection that reconstructs a P600 nearest temporally to the original P600, or selecting the projection combination - up to a preselected maximum number of combined projections providing maximum reconstructed P600 amplitude. The techniques are tested on ERPs recorded from healthy subjects and psychiatric patients, notably improving the differentiation of the two groups, based on either the amplitude or the latency of the reconstructed P600 component, in comparison to results achieved using the original ERPs.

  9. Event-related potentials with the Stroop colour-word task: timing of semantic conflict.

    Science.gov (United States)

    Zurrón, Montserrat; Pouso, María; Lindín, Mónica; Galdo, Santiago; Díaz, Fernando

    2009-06-01

    Event-Related Potentials (ERPs) elicited by congruent and incongruent colour-word stimuli of a Stroop paradigm, in a task in which participants were required to judge the congruence/incongruence of the two dimensions of the stimuli, were recorded in order to study the timing of the semantic conflict. The reaction time to colour-word incongruent stimuli was significantly longer than the reaction time to congruent stimuli (the Stroop effect). A temporal Principal Components Analysis was applied to the data to identify the ERP components. Three positive components were identified in the 300-600 ms interval in response to the congruent and incongruent stimuli: First P3, P3b and PSW. The factor scores corresponding to the First P3 and P3b components were significantly smaller for the incongruent stimuli than for the congruent stimuli. No differences between stimuli were observed in the factor scores corresponding to the PSW or in the ERP latencies. We conclude that the temporal locus of the semantic conflict, which intervenes in generating the Stroop effect, may occur within the time interval in which the First P3 and P3b components are identified, i.e. at approximately 300-450 ms post-stimulus. We suggest that the semantic conflict delays the start of the response selection process, which explains the longer reaction time to incongruent stimuli.

  10. Facial attractiveness modulates early and late event-related brain potentials.

    Science.gov (United States)

    Werheid, Katja; Schacht, Annekathrin; Sommer, Werner

    2007-09-01

    Facial attractiveness is of high importance for human interaction and communication, and everyday experience suggests that the mere aspect of a face elicits spontaneous appraisal of attractiveness. However, little is known about the time course of brain responses related to this process. In the present study, event-related brain potentials were recorded during attractiveness classification of facial portraits that were standardized with respect to facial expression. The faces were either preceded by another face of high or low attractiveness or by an affectively neutral object. Attractive as opposed to non-attractive target faces elicited an early posterior negativity (EPN; approximately 250 ms) and a late parietal positivity (LPC; 400-600 ms), which were not modulated by affectively congruent prime faces. Elevated LPC activity had previously been shown in response to attractive versus non-attractive faces, possibly reflecting task-related evaluative processes. An enhanced EPN had been reported for faces with emotional compared to neutral emotional expression, and related to facilitated selection of emotional information. Extending these findings, our study is the first to report an attractiveness-related ERP modulation prior to the LPC, suggesting that appraising facial attractiveness starts already at processing stages associated with stimulus selection.

  11. Brain functions after sports-related concussion: insights from event-related potentials and functional MRI.

    Science.gov (United States)

    Gosselin, Nadia; Saluja, Rajeet Singh; Chen, Jen-Kai; Bottari, Carolina; Johnston, Karen; Ptito, Alain

    2010-10-01

    The high incidence of concussions in contact sports and their impact on brain functions are a major cause for concern. To improve our understanding of brain functioning after sports-related concussion, advanced functional assessment techniques, namely event-related potentials (ERPs) and functional magnetic resonance imaging (fMRI), have been recently used in research studies. Contrary to neuropsychological tests that measure verbal and/or motor responses, ERPs and fMRI assess the neural activities associated with cognitive/behavioral demands, and thus provide access to better comprehension of brain functioning. In fact, ERPs have excellent temporal resolution, and fMRI identifies the involved structures during a task. This article describes ERP and fMRI techniques and reviews the results obtained with these tools in sports-related concussion. Although these techniques are not yet readily available, they offer a unique clinical approach, particularly for complex cases (ie, athletes with multiple concussions, chronic symptoms) and objective measures that provide valuable information to guide management and return-to-play decision making.

  12. Single-trial event-related potential extraction through one-unit ICA-with-reference

    Science.gov (United States)

    Lih Lee, Wee; Tan, Tele; Falkmer, Torbjörn; Leung, Yee Hong

    2016-12-01

    Objective. In recent years, ICA has been one of the more popular methods for extracting event-related potential (ERP) at the single-trial level. It is a blind source separation technique that allows the extraction of an ERP without making strong assumptions on the temporal and spatial characteristics of an ERP. However, the problem with traditional ICA is that the extraction is not direct and is time-consuming due to the need for source selection processing. In this paper, the application of an one-unit ICA-with-Reference (ICA-R), a constrained ICA method, is proposed. Approach. In cases where the time-region of the desired ERP is known a priori, this time information is utilized to generate a reference signal, which is then used for guiding the one-unit ICA-R to extract the source signal of the desired ERP directly. Main results. Our results showed that, as compared to traditional ICA, ICA-R is a more effective method for analysing ERP because it avoids manual source selection and it requires less computation thus resulting in faster ERP extraction. Significance. In addition to that, since the method is automated, it reduces the risks of any subjective bias in the ERP analysis. It is also a potential tool for extracting the ERP in online application.

  13. Auditory processing following infantile spasms: An event-related potential study.

    Science.gov (United States)

    Fosi, Tangunu; Werner, Klaus; Boyd, Stewart G; De Haan, Michelle; Scott, Rod C; Neville, Brian G

    2017-05-01

    To investigate acoustic auditory processing in patients with recent infantile spasms (IS). Patients (n = 22; 12 female; median age 8 months; range 5-11 months) had normal preceding development, brain magnetic resonance imaging (MRI), and neurometabolic testing (West syndrome of unknown cause, uWS). Controls were healthy babies (n = 22; 11 female; median age 6 months; range 3-12 months). Event-related potentials (ERPs) and psychometry (Bayley Scales of Infant Development, Second Edition, BSID-II) took place at a month following IS remission. Following a repeated pure tone, uWS patients showed less suppression of the N100 at the mid-temporal electrodes (p = 0.006), and a prolonged response latency (p = 0.019). Their novelty P300 amplitude over the mid-temporal electrodes was halved (p = 0.001). The peak of the novelty P300 to environmental broadband sounds emerged later over the left temporal lobe in patients (p = 0.015), the lag correlating with duration of spasms (r = 0.547, p = 0.015). BSID-II scores were lower in patients (p < 0.001), with no correlation to ERP. Complex acoustic information is processed poorly following IS. This would impair language. Treatment did not reverse this phenomenon, but may have limited its severity. The data are most consistent with altered connectivity of the cortical acoustic processing areas induced by IS. Wiley Periodicals, Inc. © 2017 International League Against Epilepsy.

  14. Neural Basis of Intrinsic Motivation: Evidence from Event-Related Potentials.

    Science.gov (United States)

    Jin, Jia; Yu, Liping; Ma, Qingguo

    2015-01-01

    Human intrinsic motivation is of great importance in human behavior. However, although researchers have focused on this topic for decades, its neural basis was still unclear. The current study employed event-related potentials to investigate the neural disparity between an interesting stop-watch (SW) task and a boring watch-stop task (WS) to understand the neural mechanisms of intrinsic motivation. Our data showed that, in the cue priming stage, the cue of the SW task elicited smaller N2 amplitude than that of the WS task. Furthermore, in the outcome feedback stage, the outcome of the SW task induced smaller FRN amplitude and larger P300 amplitude than that of the WS task. These results suggested that human intrinsic motivation did exist and that it can be detected at the neural level. Furthermore, intrinsic motivation could be quantitatively indexed by the amplitude of ERP components, such as N2, FRN, and P300, in the cue priming stage or feedback stage. Quantitative measurements would also be convenient for intrinsic motivation to be added as a candidate social factor in the construction of a machine learning model.

  15. Mathematical anxiety effects on simple arithmetic processing efficiency: an event-related potential study.

    Science.gov (United States)

    Suárez-Pellicioni, M; Núñez-Peña, M I; Colomé, A

    2013-12-01

    This study uses event-related brain potentials to investigate the difficulties that high math anxious individuals face when processing dramatically incorrect solutions to simple arithmetical problems. To this end, thirteen high math-anxious (HMA) and thirteen low math-anxious (LMA) individuals were presented with simple addition problems in a verification task. The proposed solution could be correct, incorrect but very close to the correct one (small-split), or dramatically incorrect (large-split). The two groups did not differ in mathematical ability or trait anxiety. We reproduced previous results for flawed scores suggesting HMA difficulties in processing large-split solutions. Moreover, large-split solutions elicited a late positive component (P600/P3b) which was more enhanced and delayed in the HMA group. Our study proposes that the pattern of flawed scores found by previous studies (and that we replicate) has to do with HMA individuals'difficulties in inhibiting an extended processing of irrelevant information (large-split solutions). Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Cognitive processing in non-communicative patients: what can event-related potentials tell us?

    Directory of Open Access Journals (Sweden)

    Zulay Rosario Lugo

    2016-11-01

    Full Text Available Event-related potentials (ERP have been proposed to improve the differential diagnosis of non-responsive patients. We investigated the potential of the P300 as a reliable marker of conscious processing in patients with locked-in syndrome (LIS. Eleven chronic LIS patients and ten healthy subjects (HS listened to a complex-tone auditory oddball paradigm, first in a passive condition (listen to the sounds and then in an active condition (counting the deviant tones. Seven out of nine HS displayed a P300 waveform in the passive condition and all in the active condition. HS showed statistically significant changes in peak and area amplitude between conditions. Three out of seven LIS patients showed the P3 waveform in the passive condition and 5 of 7 in the active condition. No changes in peak amplitude and only a significant difference at one electrode in area amplitude were observed in this group between conditions. We conclude that, in spite of keeping full consciousness and intact or nearly intact cortical functions, compared to HS, LIS patients present less reliable results when testing with ERP, specifically in the passive condition. We thus strongly recommend applying ERP paradigms in an active condition when evaluating consciousness in non-responsive patients.

  17. A hierarchy of event-related potential markers of auditory processing in disorders of consciousness

    Directory of Open Access Journals (Sweden)

    Steve Beukema

    2016-01-01

    Full Text Available Functional neuroimaging of covert perceptual and cognitive processes can inform the diagnoses and prognoses of patients with disorders of consciousness, such as the vegetative and minimally conscious states (VS;MCS. Here we report an event-related potential (ERP paradigm for detecting a hierarchy of auditory processes in a group of healthy individuals and patients with disorders of consciousness. Simple cortical responses to sounds were observed in all 16 patients; 7/16 (44% patients exhibited markers of the differential processing of speech and noise; and 1 patient produced evidence of the semantic processing of speech (i.e. the N400 effect. In several patients, the level of auditory processing that was evident from ERPs was higher than the abilities that were evident from behavioural assessment, indicating a greater sensitivity of ERPs in some cases. However, there were no differences in auditory processing between VS and MCS patient groups, indicating a lack of diagnostic specificity for this paradigm. Reliably detecting semantic processing by means of the N400 effect in passively listening single-subjects is a challenge. Multiple assessment methods are needed in order to fully characterise the abilities of patients with disorders of consciousness.

  18. Distinguishing shyness and sociability in children: An event-related potential study.

    Science.gov (United States)

    Tang, Alva; Santesso, Diane L; Segalowitz, Sidney J; Schmidt, Louis A

    2016-02-01

    Shyness and sociability are independent personality dimensions, each with distinct behavioral and psychophysiological correlates that are conserved across development, culture, and phylogeny. However, relatively little is known regarding how shyness and sociability are instantiated in the brain, particularly during childhood and during the processing of nonsocial stimuli. Using a three-stimulus auditory oddball task, we examined whether variations in shyness and sociability were related to the N200 and P300 event-related potential (ERP) brain responses to processing task-relevant, novel, and standard auditory tones in 53 typically developing 10-year-old children. ERP amplitudes were measured at four midline scalp sites: Fz, FCz, Cz, and Pz. We found that increases in shyness were correlated with increases in target P300 amplitudes across all four head sites, increases in standard P300 amplitudes, and decreases in target P300 latencies in anterior sites. No relations were found for sociability and P300 responses. We also found that P300 amplitude in the frontal region to standard tones mediated the relation between conflicted shyness (i.e., high shyness and high sociability) and emotional instability. These results suggest that shyness and sociability are distinguishable on neurocognitive measures and that these neurocognitive measures may be putative mechanisms in understanding risk for emotional instability and a broad range of dysregulated behavioral problems observed in individuals characterized by conflicted shyness. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Distinguishing shyness and sociability in adults: An event-related electrocortical-neuroendocrine study.

    Science.gov (United States)

    Tang, Alva; Santesso, Diane L; Segalowitz, Sidney J; Schulkin, Jay; Schmidt, Louis A

    2016-09-01

    Shyness and sociability are orthogonal personality dimensions, but little is known about how the two traits are instantiated in the brain and body. Using a 3-stimulus auditory oddball task, we examined whether shyness and sociability were distinguishable on P300 event-related potentials (ERPs) in processing task-relevant, novel, and standard auditory tones in 48 young adults. ERP amplitudes were measured at four midline scalp sites (Fz, FCz, Cz, Pz). We found that shyness, but not sociability, was related to reduced frontal novelty P300 amplitudes and to high emotionality. We also found that low baseline salivary cortisol levels mediated the relation between: (a) high shyness and reduced frontal P300 amplitudes to novel tones, and (b) high shyness and high scores of emotionality. We speculate that low baseline cortisol may serve as a putative mechanism influencing central attentional states of avoidance to threat and novelty and emotional arousal in adults who are shy. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. The impact of perceived quality on online buying decisions: an event-related potentials perspective.

    Science.gov (United States)

    Wang, Jing; Han, Weiwei

    2014-10-01

    Consumer neuroscience can provide useful insights into the neural foundations of consumer decisions, such as perceived quality. One of the applications is to guide attribute configuration of products to fit consumers' expectations on the basis of individual preferences. In this study, we required 20 participants to decide whether to buy the product provided in the stimuli and to respond as soon as possible. According to their reports of expectations after the experiment, we subdivided the stimuli into two conditions. Condition 1 contained the stimuli that fit individual preferences, whereas Condition 2 contained the other stimuli. An essential component of event-related potentials (ERPs), the P300, was elicited in the two conditions and distributed over almost all parietal and occipital regions. Products in Condition 1 induced a higher P300 amplitude than those in Condition 2. The results show that evaluating product attributes is a cognitive process that modulates attention in the aforementioned regions. When participants evaluate the alternatives, categorical processing occurred on the basis of similarity judgment. The situation in Condition 1 produced a similarity overlap between the product and the expectation and resulted in a higher P300. Otherwise, there was no overlap, leading to a smaller P300. Hence, the P300 may be a useful neural endogenous indicator for measuring consumers' evaluations of products in marketing research.

  1. Event-related potential evidence of accessing gender stereotypes to aid source monitoring.

    Science.gov (United States)

    Leynes, P Andrew; Crawford, Jarret T; Radebaugh, Anne M; Taranto, Elizabeth

    2013-01-23

    Source memory for the speaker's voice (male or female) was investigated when semantic knowledge (gender stereotypes) could and could not inform the episodic source judgment while event-related potentials (ERPs) were recorded. Source accuracy was greater and response times were faster when stereotypes could predict the speaker's voice at test. Recollection supported source judgments in both conditions as indicated by significant parietal "old/new" ERP effects (500-800ms). Prototypical late ERP effects (the right frontal "old/new" effect and the late posterior negativity, LPN) were evident when source judgment was based solely on episodic memory. However, these two late ERP effects were diminished and a novel, frontal-negative ERP with left-central topography was observed when stereotypes aided source judgments. This pattern of ERP activity likely reflects activation of left frontal or left temporal lobes when semantic knowledge, in the form of a gender stereotype, is accessed to inform the episodic source judgment. Copyright © 2012 Elsevier B.V. All rights reserved.

  2. The light-makeup advantage in facial processing: Evidence from event-related potentials.

    Science.gov (United States)

    Tagai, Keiko; Shimakura, Hitomi; Isobe, Hiroko; Nittono, Hiroshi

    2017-01-01

    The effects of makeup on attractiveness have been evaluated using mainly subjective measures. In this study, event-related brain potentials (ERPs) were recorded from a total of 45 Japanese women (n = 23 and n = 22 for Experiment 1 and 2, respectively) to examine the neural processing of faces with no makeup, light makeup, and heavy makeup. To have the participants look at each face carefully, an identity judgement task was used: they were asked to judge whether the two faces presented in succession were of the same person or not. The ERP waveforms in response to the first faces were analyzed. In two experiments with different stimulus probabilities, the amplitudes of N170 and vertex positive potential (VPP) were smaller for faces with light makeup than for faces with heavy makeup or no makeup. The P1 amplitude did not differ between facial types. In a subsequent rating phase, faces with light makeup were rated as more attractive than faces with heavy makeup and no makeup. The results suggest that the processing fluency of faces with light makeup is one of the reasons why light makeup is preferred to heavy makeup and no makeup in daily life.

  3. Event-related brain responses while listening to entire pieces of music.

    Science.gov (United States)

    Poikonen, H; Alluri, V; Brattico, E; Lartillot, O; Tervaniemi, M; Huotilainen, M

    2016-01-15

    Brain responses to discrete short sounds have been studied intensively using the event-related potential (ERP) method, in which the electroencephalogram (EEG) signal is divided into epochs time-locked to stimuli of interest. Here we introduce and apply a novel technique which enables one to isolate ERPs in human elicited by continuous music. The ERPs were recorded during listening to a Tango Nuevo piece, a deep techno track and an acoustic lullaby. Acoustic features related to timbre, harmony, and dynamics of the audio signal were computationally extracted from the musical pieces. Negative deflation occurring around 100 milliseconds after the stimulus onset (N100) and positive deflation occurring around 200 milliseconds after the stimulus onset (P200) ERP responses to peak changes in the acoustic features were distinguishable and were often largest for Tango Nuevo. In addition to large changes in these musical features, long phases of low values that precede a rapid increase - and that we will call Preceding Low-Feature Phases - followed by a rapid increase enhanced the amplitudes of N100 and P200 responses. These ERP responses resembled those to simpler sounds, making it possible to utilize the tradition of ERP research with naturalistic paradigms. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

  4. Optimal digital filters for long-latency components of the event-related brain potential.

    Science.gov (United States)

    Farwell, L A; Martinerie, J M; Bashore, T R; Rapp, P E; Goddard, P H

    1993-05-01

    A fundamentally important problem for cognitive psychophysiologists is selection of the appropriate off-line digital filter to extract signal from noise in the event-related brain potential (ERP) recorded at the scalp. Investigators in the field typically use a type of finite impulse response (FIR) filter known as moving average or boxcar filter to achieve this end. However, this type of filter can produce significant amplitude diminution and distortion of the shape of the ERP waveform. Thus, there is a need to identify more appropriate filters. In this paper, we compare the performance of another type of FIR filter that, unlike the boxcar filter, is designed with an optimizing algorithm that reduces signal distortion and maximizes signal extraction (referred to here as an optimal FIR filter). We applied several different filters of both types to ERP data containing the P300 component. This comparison revealed that boxcar filters reduced the contribution of high-frequency noise to the ERP but in so doing produced a substantial attenuation of P300 amplitude and, in some cases, substantial distortions of the shape of the waveform, resulting in significant errors in latency estimation. In contrast, the optimal FIR filters preserved P300 amplitude, morphology, and latency and also eliminated high-frequency noise more effectively than did the boxcar filters. The implications of these results for data acquisition and analysis are discussed.

  5. Event-related potential signatures of perceived and imagined emotional and food real-life photos.

    Science.gov (United States)

    Marmolejo-Ramos, Fernando; Hellemans, Kim; Comeau, Amy; Heenan, Adam; Faulkner, Andrew; Abizaid, Alfonso; D'Angiulli, Amedeo

    2015-06-01

    Although food and affective pictures share similar emotional and motivational characteristics, the relationship between the neuronal responses to these stimuli is unclear. Particularly, it is not known whether perceiving and imagining food and affective stimuli elicit similar event-related potential (ERP) patterns. In this study, two ERP correlates, the early posterior negativity (EPN) and the late positive potential (LPP) for perceived and imagined emotional and food photographs were investigated. Thirteen healthy volunteers were exposed to a set of food photos, as well as unpleasant, pleasant, and neutral photos from the International Affective Picture System. In each trial, participants were first asked to view a photo (perception condition), and then to create a visual mental image of it and to rate its vividness (imagery condition). The results showed that during perception, brain regions corresponding to sensorimotor and parietal motivational (defensive and appetitive) systems were activated to different extents, producing a graded pattern of EPN and LPP responses specific to the photo content - more prominent for unpleasant than pleasant and food content. Also, an EPN signature occurred in both conditions for unpleasant content, suggesting that, compared to food or pleasant content, unpleasant content may be attended to more intensely during perception and may be represented more distinctly during imagery. Finally, compared to LLP activation during perception, as well as imagery and perception of all other content, LPP activation was significantly reduced during imagery of unpleasant photos, suggesting inhibition of unwanted memories. Results are framed within a neurocognitive working model of embodied emotions.

  6. Temporal characteristics of online syntactic sentence planning: an event-related potential study.

    Science.gov (United States)

    Timmers, Inge; Gentile, Francesco; Rubio-Gozalbo, M Estela; Jansma, Bernadette M

    2013-01-01

    During sentence production, linguistic information (semantics, syntax, phonology) of words is retrieved and assembled into a meaningful utterance. There is still debate on how we assemble single words into more complex syntactic structures such as noun phrases or sentences. In the present study, event-related potentials (ERPs) were used to investigate the time course of syntactic planning. Thirty-three volunteers described visually animated scenes using naming formats varying in syntactic complexity: from simple words ('W', e.g., "triangle", "red", "square", "green", "to fly towards"), to noun phrases ('NP', e.g., "the red triangle", "the green square", "to fly towards"), to a sentence ('S', e.g., "The red triangle flies towards the green square."). Behaviourally, we observed an increase in errors and corrections with increasing syntactic complexity, indicating a successful experimental manipulation. In the ERPs following scene onset, syntactic complexity variations were found in a P300-like component ('S'/'NP'>'W') and a fronto-central negativity (linear increase with syntactic complexity). In addition, the scene could display two actions - unpredictable for the participant, as the disambiguation occurred only later in the animation. Time-locked to the moment of visual disambiguation of the action and thus the verb, we observed another P300 component ('S'>'NP'/'W'). The data show for the first time evidence of sensitivity to syntactic planning within the P300 time window, time-locked to visual events critical of syntactic planning. We discuss the findings in the light of current syntactic planning views.

  7. Human recognition memory and conflict control: An event-related potential study.

    Science.gov (United States)

    Liu, T; Liu, X; Xiao, T; Shi, J

    2016-01-28

    The relationship between recognition memory and cognitive control is an important research topic. The current study investigated how conflict control influences an individual's emotional memory. During the encoding phase, participants were required to judge the affective valence of a Chinese Chengyu word (either positive or negative) in a modified Simon paradigm and to remember the word. Half of the words were presented in the congruent condition and the other half were displayed in the incongruent condition. During the retrieval phase, participants were instructed to make an 'old/new judgment' and decide whether the word had been presented previously. Electrophysiological responses were recorded using the event-related potential (ERP) technique. The behavioral results of retrieval processes showed that participants remembered more positive than negative words when they were encoded in the congruent condition. The electrophysiological results revealed that the retrieval of words encoded in the incongruent condition elicited less negative frontal negativity (FN) and early posterior negativity (EPN) amplitudes than those encoded in the congruent condition. The retrieval of words encoded in the incongruent condition induced greater late positive complex (LPC) amplitudes, relative to those encoded in the congruent condition on the left hemisphere. It was also observed that the recognition of positive words induced faster LPC responses than negative words when they were encoded in the incongruent condition. The present electrophysiological study illustrates that emotional memory processes may be affected by conflict control. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

  8. Multisensory integration and attention in autism spectrum disorder: evidence from event-related potentials.

    Directory of Open Access Journals (Sweden)

    Maurice J C M Magnée

    Full Text Available Successful integration of various simultaneously perceived perceptual signals is crucial for social behavior. Recent findings indicate that this multisensory integration (MSI can be modulated by attention. Theories of Autism Spectrum Disorders (ASDs suggest that MSI is affected in this population while it remains unclear to what extent this is related to impairments in attentional capacity. In the present study Event-related potentials (ERPs following emotionally congruent and incongruent face-voice pairs were measured in 23 high-functioning, adult ASD individuals and 24 age- and IQ-matched controls. MSI was studied while the attention of the participants was manipulated. ERPs were measured at typical auditory and visual processing peaks, namely, P2 and N170. While controls showed MSI during divided attention and easy selective attention tasks, individuals with ASD showed MSI during easy selective attention tasks only. It was concluded that individuals with ASD are able to process multisensory emotional stimuli, but this is differently modulated by attention mechanisms in these participants, especially those associated with divided attention. This atypical interaction between attention and MSI is also relevant to treatment strategies, with training of multisensory attentional control possibly being more beneficial than conventional sensory integration therapy.

  9. Context effects on odor processing: an event-related potential study.

    Science.gov (United States)

    Laudien, Joachim H; Wencker, Sonja; Ferstl, Roman; Pause, Bettina M

    2008-07-15

    The present study aimed to investigate the effects of cognitive/emotional bias on central nervous odor processing. Forty-five female participants were divided into three groups and were either led to believe the odor was a natural, healthy extract (positive bias), potentially hazardous (negative bias), or a common test odorant (control). The odor (isobornyl acetate) was presented via a constant-flow olfactometer and the EEG was recorded from 60 scalp locations. In the negative bias condition, participants reported reduced well-being and judged the odor as less pleasant. However, neither the thresholds nor the intensity ratings were changed by the context condition. Chemosensory event-related potential (CSERP) analysis revealed that the latencies of the N1 and P2 components were prolonged in the negative bias condition and shortened in the positive bias condition. Current source densities were most prominent in the frontal lobe in negatively biased participants. The findings show that expecting to perceive an emotionally significant odor affects the early encoding of odors.

  10. The role of event-related brain potentials in assessing central auditory processing.

    Science.gov (United States)

    Alain, Claude; Tremblay, Kelly

    2007-01-01

    The perception of complex acoustic signals such as speech and music depends on the interaction between peripheral and central auditory processing. As information travels from the cochlea to primary and associative auditory cortices, the incoming sound is subjected to increasingly more detailed and refined analysis. These various levels of analyses are thought to include low-level automatic processes that detect, discriminate and group sounds that are similar in physical attributes such as frequency, intensity, and location as well as higher-level schema-driven processes that reflect listeners' experience and knowledge of the auditory environment. In this review, we describe studies that have used event-related brain potentials in investigating the processing of complex acoustic signals (e.g., speech, music). In particular, we examine the role of hearing loss on the neural representation of sound and how cognitive factors and learning can help compensate for perceptual difficulties. The notion of auditory scene analysis is used as a conceptual framework for interpreting and studying the perception of sound.

  11. Interactions between the perception of age and ethnicity in faces: an event-related potential study.

    Science.gov (United States)

    Alonso-Prieto, Esther; Oruç, Ipek; Rubino, Cristina; Zhu, Maria; Handy, Todd; Barton, Jason J S

    2015-01-01

    Face perception models propose that different facial attributes are processed by anatomically distinct neural pathways that partially overlap. Whether these attributes interact functionally is an open question. Our goal was to determine if there are interactions between age and ethnicity processing and, if so, at what temporal epoch these interactions are evident. We monitored event-related potentials on electroencephalography while subjects categorized faces by age or ethnicity in two conditions: a baseline in which the other of these two properties not being categorized was held constant and an interference condition in which it also varied, as modelled after the Garner interference paradigm. We found that, when participants were categorizing faces by age, variations in ethnicity increased the amplitude of the right face-selective N170 component. When subjects were categorizing faces by ethnicity, variations in age did not alter the N170. We concluded that there is an asymmetric pattern of influence between age and ethnicity on early face-specific stages of visual processing, which has parallels with behavioural evidence of asymmetric interactions between identity and expression processing of faces.

  12. Short-term effects of prosocial video games on aggression: an event-related potential study

    Science.gov (United States)

    Liu, Yanling; Teng, Zhaojun; Lan, Haiying; Zhang, Xin; Yao, Dezhong

    2015-01-01

    Previous research has shown that exposure to violent video games increases aggression, whereas exposure to prosocial video games can reduce aggressive behavior. However, little is known about the neural correlates of these behavioral effects. This work is the first to investigate the electrophysiological features of the relationship between playing a prosocial video game and inhibition of aggressive behavior. Forty-nine subjects played either a prosocial or a neutral video game for 20 min, then participated in an event-related potential (ERP) experiment based on an oddball paradigm and designed to test electrophysiological responses to prosocial and violent words. Finally, subjects completed a competitive reaction time task (CRTT) which based on Taylor's Aggression Paradigm and contains reaction time and noise intensity chosen as a measure of aggressive behavior. The results show that the prosocial video game group (compared to the neutral video game group) displayed smaller P300 amplitudes, were more accurate in distinguishing violent words, and were less aggressive as evaluated by the CRTT of noise intensity chosen. A mediation analysis shows that the P300 amplitude evoked by violent words partially mediates the relationship between type of video game and subsequent aggressive behavior. The results support theories based on the General Learning Model. We provide converging behavioral and neural evidence that exposure to prosocial media may reduce aggression. PMID:26257620

  13. Lexical ambiguity resolution during sentence processing in Parkinson's disease: An event-related potential study.

    Directory of Open Access Journals (Sweden)

    Anthony J Angwin

    Full Text Available Event-related potentials (ERPs were recorded to investigate lexical ambiguity resolution during sentence processing in 16 people with Parkinson's disease (PD and 16 healthy controls. Sentences were presented word-by-word on computer screen, and participants were required to decide if a subsequent target word was related to the meaning of the sentence. The task consisted of related, unrelated and ambiguous trials. For the ambiguous trials, the sentence ended with an ambiguous word and the target was related to one of the meanings of that word, but not the one captured by the sentence context (e.g., 'He dug with the spade', Target 'ACE'. Both groups demonstrated slower reaction times and lower accuracy for the ambiguous condition relative to the unrelated condition, however accuracy was impacted by the ambiguous condition to a larger extent in the PD group. These results suggested that PD patients experience increased difficulties with contextual ambiguity resolution. The ERP results did not reflect increased ambiguity resolution difficulties in PD, as a similar N400 effect was evident for the unrelated and ambiguous condition in both groups. However, the magnitude of the N400 for these conditions was correlated with a measure of inhibition in the PD group, but not the control group. The ERP results suggest that semantic processing may be more compromised in PD patients with increased response inhibition deficits.

  14. [Event-related EEG potentials associated with error detection in psychiatric disorder: literature review].

    Science.gov (United States)

    Balogh, Lívia; Czobor, Pál

    2010-01-01

    Error-related bioelectric signals constitute a special subgroup of event-related potentials. Researchers have identified two evoked potential components to be closely related to error processing, namely error-related negativity (ERN) and error-positivity (Pe), and they linked these to specific cognitive functions. In our article first we give a brief description of these components, then based on the available literature, we review differences in error-related evoked potentials observed in patients across psychiatric disorders. The PubMed and Medline search engines were used in order to identify all relevant articles, published between 2000 and 2009. For the purpose of the current paper we reviewed publications summarizing results of clinical trials. Patients suffering from schizophrenia, anorexia nervosa or borderline personality disorder exhibited a decrease in the amplitude of error-negativity when compared with healthy controls, while in cases of depression and anxiety an increase in the amplitude has been observed. Some of the articles suggest specific personality variables, such as impulsivity, perfectionism, negative emotions or sensitivity to punishment to underlie these electrophysiological differences. Research in the field of error-related electric activity has come to the focus of psychiatry research only recently, thus the amount of available data is significantly limited. However, since this is a relatively new field of research, the results available at present are noteworthy and promising for future electrophysiological investigations in psychiatric disorders.

  15. Attentional biases in children of depressed mothers: An event-related potential (ERP) study.

    Science.gov (United States)

    Gibb, Brandon E; Pollak, Seth D; Hajcak, Greg; Owens, Max

    2016-11-01

    Although a number of studies have reported that children of depressed, compared to nondepressed, parents exhibit biased attention to sad facial stimuli, the direction of this bias remains unclear; some studies find evidence of preferential attention toward sad faces whereas others find evidence of attention avoidance. In the current study, we used event-related potentials (ERPs) to assess children's attention to emotional stimuli using a spatial cueing task. Across all indices of attention bias (N2pc and sustained posterior contralateral negativity [SPCN] time locked to face onset, P3b time locked to probe onset, reaction times [RTs] to probes), children of mothers with a history of major depressive disorder (MDD) during the child's life exhibited less attention to sad faces than children of never depressed mothers. For two of these indices (SPCN and RTs), the attention biases for the offspring of depressed mothers was not specific to sadness and was observed for all emotional expressions. Group differences in the ERP indices were maintained when controlling for the influence of mothers' and children's current symptoms of depression and anxiety, mothers' history of anxiety disorders, and children's history of MDD and anxiety disorders, suggesting that the results are specific to mothers' history of MDD. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  16. Neurofeedback in children with ADHD: specific event-related potential findings of a randomized controlled trial.

    Science.gov (United States)

    Wangler, Susanne; Gevensleben, Holger; Albrecht, Björn; Studer, Petra; Rothenberger, Aribert; Moll, Gunther H; Heinrich, Hartmut

    2011-05-01

    In a randomized controlled trial, we could demonstrate clinical efficacy of neurofeedback (NF) training for children with ADHD (Gevensleben et al., 2009a). The present investigation aimed at learning more about the neuronal mechanisms of NF training. Children with ADHD either completed a NF training or a computerized attention skills training (ratio 3:2). NF training consisted of one block of theta/beta training and one block of slow cortical potential (SCP) training, each comprising 18 training units. At three times (pre-training, between the two training blocks and at post-training), event-related potentials (ERP) were recorded during the Attention Network Test. ERP analysis focused on the P3, reflecting inter alia attentional resources for stimulus evaluation, and the contingent negative variation (CNV), primarily related to cognitive preparation. After NF training, an increase of the CNV in cue trials could be observed, which was specific for the SCP training. A larger pre-training CNV was associated with a larger reduction of ADHD symptomatology for SCP training. CNV effects reflect neuronal circuits underlying resource allocation during cognitive preparation. These distinct ERP effects are closely related to a successful NF training in children with ADHD. In future studies, neurophysiological recordings could help to optimize and individualize NF training. The findings contribute to a better understanding of the mechanisms underlying NF training in children with ADHD. Copyright © 2010 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  17. An event-related potential study of semantic style-match judgments of artistic furniture.

    Science.gov (United States)

    Lin, Ming-Huang; Wang, Ching-yi; Cheng, Shih-kuen; Cheng, Shih-hung

    2011-11-01

    This study investigates how semantic networks represent different artistic furniture. Event-related potentials (ERPs) were recorded while participants made style-match judgments for table and chair sets. All of the tables were in the Normal style, whereas the chairs were in the Normal, Minimal, ReadyMade, or Deconstruction styles. The Normal and Minimal chairs had the same rates of "match" responses, which were both higher than the rates for the ReadyMade and Deconstruction chairs. Compared with Normal chairs, the ERPs elicited by both ReadyMade chairs and Deconstruction chairs exhibited reliable N400 effects, which suggests that these two design styles were unlike the Normal design style. However, Minimal chairs evoked ERPs that were similar to the ERPs of Normal chairs. Furthermore, the N400 effects elicited by ReadyMade and Deconstruction chairs showed different scalp distributions. These findings reveal that semantic networks represent different design styles for items of the same category. Copyright © 2011 Elsevier B.V. All rights reserved.

  18. Event-related potentials for 7-month-olds' processing of animals and furniture items.

    Science.gov (United States)

    Elsner, Birgit; Jeschonek, Susanna; Pauen, Sabina

    2013-01-01

    Event-related potentials (ERPs) to single visual stimuli were recorded in 7-month-old infants. In a three-stimulus oddball paradigm, infants watched one frequently occurring standard stimulus (either an animal or a furniture item) and two infrequently occurring oddball stimuli, presenting one exemplar from the same and one from the different superordinate category as compared to the standard stimulus. Additionally, visual attributes of the stimuli were controlled to investigate whether infants focus on category membership or on perceptual similarity when processing the stimuli. Infant ERPs indicated encoding of the standard stimulus and discriminating it from the two oddball stimuli by larger Nc peak amplitude and late-slow-wave activity for the infrequent stimuli. Moreover, larger Nc latency and positive-slow-wave activity indicated increased processing for the different-category as compared to the same-category oddball. Thus, 7-month-olds seem to encode single stimuli not only by surface perceptual features, but they also regard information of category membership, leading to facilitated processing of the oddball that belongs to the same domain as the standard stimulus. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. Snake scales, partial exposure, and the Snake Detection Theory: A human event-related potentials study

    Science.gov (United States)

    Van Strien, Jan W.; Isbell, Lynne A.

    2017-01-01

    Studies of event-related potentials in humans have established larger early posterior negativity (EPN) in response to pictures depicting snakes than to pictures depicting other creatures. Ethological research has recently shown that macaques and wild vervet monkeys respond strongly to partially exposed snake models and scale patterns on the snake skin. Here, we examined whether snake skin patterns and partially exposed snakes elicit a larger EPN in humans. In Task 1, we employed pictures with close-ups of snake skins, lizard skins, and bird plumage. In task 2, we employed pictures of partially exposed snakes, lizards, and birds. Participants watched a random rapid serial visual presentation of these pictures. The EPN was scored as the mean activity (225–300 ms after picture onset) at occipital and parieto-occipital electrodes. Consistent with previous studies, and with the Snake Detection Theory, the EPN was significantly larger for snake skin pictures than for lizard skin and bird plumage pictures, and for lizard skin pictures than for bird plumage pictures. Likewise, the EPN was larger for partially exposed snakes than for partially exposed lizards and birds. The results suggest that the EPN snake effect is partly driven by snake skin scale patterns which are otherwise rare in nature. PMID:28387376

  20. An Event-Related Potential Study on the Effects of Cannabis on Emotion Processing

    Science.gov (United States)

    Troup, Lucy J.; Bastidas, Stephanie; Nguyen, Maia T.; Andrzejewski, Jeremy A.; Bowers, Matthew; Nomi, Jason S.

    2016-01-01

    The effect of cannabis on emotional processing was investigated using event-related potential paradigms (ERPs). ERPs associated with emotional processing of cannabis users, and non-using controls, were recorded and compared during an implicit and explicit emotional expression recognition and empathy task. Comparisons in P3 component mean amplitudes were made between cannabis users and controls. Results showed a significant decrease in the P3 amplitude in cannabis users compared to controls. Specifically, cannabis users showed reduced P3 amplitudes for implicit compared to explicit processing over centro-parietal sites which reversed, and was enhanced, at fronto-central sites. Cannabis users also showed a decreased P3 to happy faces, with an increase to angry faces, compared to controls. These effects appear to increase with those participants that self-reported the highest levels of cannabis consumption. Those cannabis users with the greatest consumption rates showed the largest P3 deficits for explicit processing and negative emotions. These data suggest that there is a complex relationship between cannabis consumption and emotion processing that appears to be modulated by attention. PMID:26926868

  1. Meditation (Vipassana) and the P3a event-related brain potential.

    Science.gov (United States)

    Cahn, B Rael; Polich, John

    2009-04-01

    A three-stimulus auditory oddball series was presented to experienced Vipassana meditators during meditation and a control thought period to elicit event-related brain potentials (ERPs) in the two different mental states. The stimuli consisted of a frequent standard tone (500 Hz), an infrequent oddball tone (1000 Hz), and an infrequent distracter (white noise), with all stimuli passively presented through headphones and no task imposed. The strongest meditation compared to control state effects occurred for the distracter stimuli: N1 amplitude from the distracter was reduced frontally during meditation; P2 amplitude from both the distracter and oddball stimuli were somewhat reduced during meditation; P3a amplitude from the distracter was reduced during meditation. The meditation-induced reduction in P3a amplitude was strongest in participants reporting more hours of daily meditation practice and was not evident in participants reporting drowsiness during their experimental meditative session. The findings suggest that meditation state can decrease the amplitude of neurophysiologic processes that subserve attentional engagement elicited by unexpected and distracting stimuli. Consistent with the aim of Vipassana meditation to reduce cognitive and emotional reactivity, the state effect of reduced P3a amplitude to distracting stimuli reflects decreased automated reactivity and evaluative processing of task irrelevant attention-demanding stimuli.

  2. Clinical high risk and first episode schizophrenia: Auditory event-related potentials

    Science.gov (United States)

    del Re, Elisabetta C.; Spencer, Kevin M.; Oribe, Naoya; Mesholam-Gately, Raquelle I.; Goldstein, Jill; Shenton, Martha E.; Petryshen, Tracey; Seidman, Larry J.; McCarley, Robert W.; Niznikiewicz, Margaret A.

    2014-01-01

    The clinical high risk (CHR) period is a phase denoting a risk for overt psychosis during which subacute symptoms often appear, and cognitive functions may deteriorate. To compare biological indices during this phase with those during first episode schizophrenia, we cross-sectionally examined sex- and age-matched clinical high risk (CHR, n=21), first episode schizophrenia patients (FESZ, n=20) and matched healthy controls (HC, n=25) on oddball and novelty paradigms and assessed the N100, P200, P3a and P3b as indices of perceptual, attentional and working memory processes. To our knowledge, this is the only such comparison using all of these event-related potentials (ERPs) in two paradigms. We hypothesized that the ERPs would differentiate between the three groups and allow prediction of a diagnostic group. The majority of ERPs were significantly affected in CHR and FESZ compared with controls, with similar effect sizes. Nonetheless, in logistic regression, only the P3a and N100 distinguished CHR and FESZ from healthy controls, suggesting that ERPs not associated with an overt task might be more sensitive to prediction of group membership. PMID:25557063

  3. Event-related P3a and P3b in response to unpredictable emotional stimuli.

    Science.gov (United States)

    Delplanque, Sylvain; Silvert, Laetitia; Hot, Pascal; Sequeira, Henrique

    2005-02-01

    In natural situations, unpredictable events processing often interacts with the ongoing cognitive activities. In a similar manner, the insertion of deviant unpredictable stimuli into a classical oddball task evokes both the P3a and P3b event-related potentials (ERPs) components that are, respectively, thought to index reallocation of attentional resources or inhibitory process and memory updating mechanism. This study aims at characterising the influence of the emotional arousal and valence of a deviant and unpredictable non-target stimulus on these components. ERPs were recorded from 28 sites during a visual three-stimulus oddball paradigm. Unpleasant, neutral and pleasant pictures served as non-target unpredictable items and subjects were asked to realize a perceptually difficult standard/target discrimination task. A temporal principal component analysis (PCA) allowed us to show that non-target pictures elicited both a P3a and a P3b. Moreover, the P3b component was modulated by the emotional arousal and the valence of the pictures. Thus, the memory updating process may be modulated by the affective arousal and valence of unpredictable disturbing stimuli, even if the task does not require any explicit emotional categorization.

  4. The pain-evoked P2 is not a P3a event-related potential.

    Science.gov (United States)

    Dowman, Robert

    2004-01-01

    The topographic pattern and latency of the P2 component of the somatosensory evoked potential elicited by painful electrical stimulation of the sural nerve was compared to the P3a event-related potential evoked by an infrequent task-irrelevant (deviant) innocuous sural nerve stimulus presented as part of the deviant-odd ball paradigm. Conditions typically used to record the sural nerve pain-evoked P2 (multiple stimulus levels, short fixed inter-stimulus intervals, and the subjects engaged in a pain rating task) did not elicit a P3a. The P3a was elicited when the painful stimuli were presented at a long and variable inter-stimulus interval. When present, the P3a occurred immediately following P2. These findings demonstrate that P2 is not a pain-evoked P3a. Rather, the response properties and latency of P2 present the possibility that it indexes a stimulus evaluation process where the sensory input is compared to an environmental template maintained by working memory.

  5. An event related potential study of inhibitory and attentional control in Williams syndrome adults

    Science.gov (United States)

    Greer, Joanna M. H.; Hamilton, Colin; Riby, Leigh M.

    2017-01-01

    The primary aim of the current study was to employ event-related potentials (ERPs) methodology to disentangle the mechanisms related to inhibitory control in older adults with Williams syndrome (WS). Eleven older adults with WS (mean age 42), 16 typically developing adults (mean age 42) and 13 typically developing children (mean age 12) participated in the study. ERPs were recorded during a three-stimulus visual oddball task, during which participants were required to make a response to a rare target stimulus embedded in a train of frequent non-target stimuli. A task-irrelevant infrequent stimulus was also present at randomised intervals during the session. The P3a latency data response related to task-irrelevant stimulus processing was delayed in WS. In addition, the early perceptual N2 amplitude was attenuated. These data are indicative of compromised early monitoring of perceptual input, accompanied by appropriate orientation of responses to task-irrelevant stimuli. However, the P3a delay suggests inefficient evaluation of the task-irrelevant stimuli. These data are discussed in terms of deficits in the disengagement of attentional processes, and the regulation of monitoring processes required for successful inhibition. PMID:28187205

  6. Analysis of events related to cracks and leaks in the reactor coolant pressure boundary

    Energy Technology Data Exchange (ETDEWEB)

    Ballesteros, Antonio, E-mail: Antonio.Ballesteros-Avila@ec.europa.eu [JRC-IET: Institute for Energy and Transport of the Joint Research Centre of the European Commission, Postbus 2, NL-1755 ZG Petten (Netherlands); Sanda, Radian; Peinador, Miguel; Zerger, Benoit [JRC-IET: Institute for Energy and Transport of the Joint Research Centre of the European Commission, Postbus 2, NL-1755 ZG Petten (Netherlands); Negri, Patrice [IRSN: Institut de Radioprotection et de Sûreté Nucléaire (France); Wenke, Rainer [GRS: Gesellschaft für Anlagen- und Reaktorsicherheit (GRS) mbH (Germany)

    2014-08-15

    Highlights: • The important role of Operating Experience Feedback is emphasised. • Events relating to cracks and leaks in the reactor coolant pressure boundary are analysed. • A methodology for event investigation is described. • Some illustrative results of the analysis of events for specific components are presented. - Abstract: The presence of cracks and leaks in the reactor coolant pressure boundary may jeopardise the safe operation of nuclear power plants. Analysis of cracks and leaks related events is an important task for the prevention of their recurrence, which should be performed in the context of activities on Operating Experience Feedback. In response to this concern, the EU Clearinghouse operated by the JRC-IET supports and develops technical and scientific work to disseminate the lessons learned from past operating experience. In particular, concerning cracks and leaks, the studies carried out in collaboration with IRSN and GRS have allowed to identify the most sensitive areas to degradation in the plant primary system and to elaborate recommendations for upgrading the maintenance, ageing management and inspection programmes. An overview of the methodology used in the analysis of cracks and leaks related events is presented in this paper, together with the relevant results obtained in the study.

  7. Short-term effects of prosocial video games on aggression: an event-related potential study.

    Science.gov (United States)

    Liu, Yanling; Teng, Zhaojun; Lan, Haiying; Zhang, Xin; Yao, Dezhong

    2015-01-01

    Previous research has shown that exposure to violent video games increases aggression, whereas exposure to prosocial video games can reduce aggressive behavior. However, little is known about the neural correlates of these behavioral effects. This work is the first to investigate the electrophysiological features of the relationship between playing a prosocial video game and inhibition of aggressive behavior. Forty-nine subjects played either a prosocial or a neutral video game for 20 min, then participated in an event-related potential (ERP) experiment based on an oddball paradigm and designed to test electrophysiological responses to prosocial and violent words. Finally, subjects completed a competitive reaction time task (CRTT) which based on Taylor's Aggression Paradigm and contains reaction time and noise intensity chosen as a measure of aggressive behavior. The results show that the prosocial video game group (compared to the neutral video game group) displayed smaller P300 amplitudes, were more accurate in distinguishing violent words, and were less aggressive as evaluated by the CRTT of noise intensity chosen. A mediation analysis shows that the P300 amplitude evoked by violent words partially mediates the relationship between type of video game and subsequent aggressive behavior. The results support theories based on the General Learning Model. We provide converging behavioral and neural evidence that exposure to prosocial media may reduce aggression.

  8. Effects of oxazepam on affective perception, recognition, and event-related potentials.

    Science.gov (United States)

    Olofsson, Jonas K; Gospic, Katarina; Petrovic, Predrag; Ingvar, Martin; Wiens, Stefan

    2011-05-01

    Little is known about how rapid electrocortical responses (event-related potentials; ERPs) to affective pictures are modulated by benzodiazepine agonists. The present study investigated effects of oxazepam (20 mg p.o.) on behavioral measures and ERPs associated with affective picture processing during perception and recognition memory retrieval. Forty-three healthy young adults were given oxazepam or placebo treatment under a double-blind experimental procedure. Affective pictures (negatively arousing or neutral) elicited ERP responses and participants rated pictures for emotionality (during incidental encoding) and recognition. Oxazepam did not affect perceptual (P1, P2) or emotional (early posterior negativity and late parietal positivity) ERPs or ratings during perception. However, oxazepam impaired recognition performance and decreased positive mid-frontal ERP component at 420-450 ms for old vs. new pictures. The memory impairment was retained at the delayed memory test. Oxazepam does not selectively influence electrocortical or perceptual indexes of emotional perception or emotional memory. Rather, it blocks memory consolidation independent of valence category. These findings indicate that ERPs can be of use in assessing effects of benzodiazepines on memory-related processes.

  9. Event-related potential effects of superior action anticipation in professional badminton players.

    Science.gov (United States)

    Jin, Hua; Xu, Guiping; Zhang, John X; Gao, Hongwei; Ye, Zuoer; Wang, Pin; Lin, Huiyan; Mo, Lei; Lin, Chong-De

    2011-04-04

    The ability to predict the trajectory of a ball based on the opponent's body kinematics has been shown to be critical to high-performing athletes in many sports. However, little is known about the neural correlates underlying such superior ability in action anticipation. The present event-related potential study compared brain responses from professional badminton players and non-player controls when they watched video clips of badminton games and predicted a ball's landing position. Replicating literature findings, the players made significantly more accurate judgments than the controls and showed better action anticipation. Correspondingly, they showed enlarged amplitudes of two ERP components, a P300 peaking around 350ms post-stimulus with a parietal scalp distribution and a P2 peaking around 250ms with a posterior-occipital distribution. The P300 effect was interpreted to reflect primed access and/or directing of attention to game-related memory representations in the players facilitating their online judgment of related actions. The P2 effect was suggested to reflect some generic learning effects. The results identify clear neural responses that differentiate between different levels of action anticipation associated with sports expertise. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  10. Relationship between early and late stages of information processing: an event-related potential study

    Science.gov (United States)

    Portella, Claudio; Machado, Sergio; Arias-Carrión, Oscar; Sack, Alexander T.; Silva, Julio Guilherme; Orsini, Marco; Leite, Marco Antonio Araujo; Silva, Adriana Cardoso; Nardi, Antonio E.; Cagy, Mauricio; Piedade, Roberto; Ribeiro, Pedro

    2012-01-01

    The brain is capable of elaborating and executing different stages of information processing. However, exactly how these stages are processed in the brain remains largely unknown. This study aimed to analyze the possible correlation between early and late stages of information processing by assessing the latency to, and amplitude of, early and late event-related potential (ERP) components, including P200, N200, premotor potential (PMP) and P300, in healthy participants in the context of a visual oddball paradigm. We found a moderate positive correlation among the latency of P200 (electrode O2), N200 (electrode O2), PMP (electrode C3), P300 (electrode PZ) and the reaction time (RT). In addition, moderate negative correlation between the amplitude of P200 and the latencies of N200 (electrode O2), PMP (electrode C3), P300 (electrode PZ) was found. Therefore, we propose that if the secondary processing of visual input (P200 latency) occurs faster, the following will also happen sooner: discrimination and classification process of this input (N200 latency), motor response processing (PMP latency), reorganization of attention and working memory update (P300 latency), and RT. N200, PMP, and P300 latencies are also anticipated when higher activation level of occipital areas involved in the secondary processing of visual input rise (P200 amplitude). PMID:23355929

  11. The impact of attentional training on event-related potentials in older adults.

    Science.gov (United States)

    Zendel, Benjamin Rich; de Boysson, Chloé; Mellah, Samira; Démonet, Jean-François; Belleville, Sylvie

    2016-11-01

    Attentional control declines in older adults and is paralleled by changes in event-related brain potentials (ERPs). The N200 is associated with attentional control, thus training-related improvements in attentional control should be paralleled by enhancements to the N200. Older participants were randomly assigned to 1 of 3 groups, which focused on training different levels of attentional control: (1) single-task training (single), where participants trained on 2 tasks in isolation; (2) fixed divided attention training (fixed), where participants trained on 2 tasks simultaneously; and (3) variable divided attention training (variable), where participants trained on 2 tasks simultaneously but were instructed to alternatively prioritize each of the 2 tasks. After training, the amplitude of the N200 wave increased in dual-task conditions for the variable group, and this enhancement was correlated with improved dual-task performance. Participants in the variable group also had the greatest improvement in the ability to modulate their allocation of attention in accordance with task instructions to the less salient and less complex of the 2 tasks. Training older adults to modulate their division of attention between tasks improves neural functions associated with attentional control of the trained tasks. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

  12. Antiherding in Financial Decision Increases Valuation of Return on Investment: An Event-Related Potential Study.

    Science.gov (United States)

    Wang, Cuicui; Jin, Jia; Vieito, João Paulo; Ma, Qingguo

    2017-01-01

    Using event-related potentials, this study investigated how financial herding or antiherding affected the valuation of subsequent outcomes. For each trial, subjects decided whether to buy the stock according to its net money flow information which could be used to reflect the strength of buying power or selling power of the stock. The return on investment (ROI) as feedback included the increase or decrease percentage after subjects' responses. Results showed that, compared with herding, antiherding induced larger discrepancies of FRN and P300 amplitude between positive ROI and negative ROI, indicating that individuals under antiherding condition had stronger motivation and paid more attention in the evaluation process of ROI. Moreover, only for positive ROI, the amplitudes of FRN and P300 were modulated by two kinds of behaviors. We suggested that individuals making antiherd decisions were more confident with their own ability and choices, which reduced the positive outcome prediction error and gave more mental resources to evaluate positive outcome. However, negative outcomes evoked no different motivational meaning and negative emotion for individuals between herding and antiherding. The study may provide new insights into neurocognitive processes of herding and antiherding in financial market.

  13. Indexing strategic retrieval of colour information with event-related potentials.

    Science.gov (United States)

    Wilding, E L; Fraser, C S; Herron, J E

    2005-09-01

    Event-related potentials (ERPs) were acquired during two experiments in order to determine boundary conditions for when recollection of colour information can be controlled strategically. In initial encoding phases, participants saw an equal number of words presented in red or green. In subsequent retrieval phases, all words were shown in white. Participants were asked to endorse old words that had been shown at encoding in one colour (targets), and to reject new test words as well as old words shown in the alternate colour (non-targets). Study and test lists were longer in Experiment 1, and as a result, the accuracy of memory judgments was superior in Experiment 2. The left-parietal ERP old/new effect--the electrophysiological signature of recollection--was reliable for targets in both experiments, and reliable for non-targets in Experiment 1 only. These findings are consistent with the view that participants were able to restrict recollection to targets in Experiment 2, while recollecting information about targets as well as non-targets in Experiment 1. The fact that this selective strategy was implemented in Experiment 2 despite the close correspondence between the kinds of information associated with targets and non-targets indicates that participants were able to exert considerable control over the conditions under which recollection of task-relevant information occurred.

  14. Rejection in Bargaining Situations: An Event-Related Potential Study in Adolescents and Adults.

    Directory of Open Access Journals (Sweden)

    Kiki Zanolie

    Full Text Available The neural correlates of rejection in bargaining situations when proposing a fair or unfair offer are not yet well understood. We measured neural responses to rejection and acceptance of monetary offers with event-related potentials (ERPs in mid-adolescents (14-17 years and early adults (19-24 years. Participants played multiple rounds of the Ultimatum Game as proposers, dividing coins between themselves and a second player (responder by making a choice between an unfair distribution (7 coins for proposer and 3 for responder; 7/3 and one of two alternatives: a fair distribution (5/5 or a hyperfair distribution (3/7. Participants mostly made fair offers (5/5 when the alternative was unfair (7/3, but made mostly unfair offers (7/3 when the alternative was hyperfair (3/7. When participants' fair offers (5/5; alternative was 7/3 were rejected this was associated with a larger Medial Frontal Negativity (MFN compared to acceptance of fair offers and rejection of unfair offers (7/3; alternative was 3/7. Also, the MFN was smaller after acceptance of unfair offers (7/3 compared to rejection. These neural responses did not differ between adults and mid-adolescents, suggesting that the MFN reacts as a neural alarm system to social prediction errors which is already prevalent during adolescence.

  15. Estimation of single event-related potentials utilizing the Prony method.

    Science.gov (United States)

    Hansson, M; Gänsler, T; Salomonsson, G

    1996-10-01

    This paper deals with estimation of the waveform of a single event-related potential, sERP. An additive noise model is used for the measured signal and the SNR of the disturbed sERP is approximately 0 dB. The sERP is described by a series expansion where the basis functions are damped sinusoids. The fundamental basis function is estimated by the least squares Prony method, derived for colored noise. The performance of the Prony method for different forms of the power density spectrum of the noise is investigated. A white noise approximation can be used at a low signal-to-noise (SNR). The basis functions change slowly but the waveform of the sERP may vary from one stimulus to another, thus we average a small number of correlation functions in order to increase the SNR. The method is evaluated by using measurements from four subjects and the results confirm the variability of the sERP.

  16. Location negative priming effects in children with developmental dyslexia: An event-related potential study.

    Science.gov (United States)

    Ma, Yujun; Wang, Enguo; Yuan, Tian; Zhao, Guo Xiang

    2016-08-01

    As the reading process is inseparable from working memory, inhibition, and other higher cognitive processes, the deep cognitive processing defects that are associated with dyslexia may be due to defective distraction inhibition systems. In this study, we used event-related potential technology to explore the source of negative priming effects in children with developmental dyslexia and in a group of healthy children for comparison. We found that the changes in the average response times in the negative priming and control conditions were consistent across the two groups, while the negative priming effects differed significantly between the groups. The magnitude of the negative priming effect was significantly different between the two groups, with the magnitude being significantly higher in the control group than it was in the developmental dyslexia group. These results indicate that there are deficits in distraction inhibition in children with developmental dyslexia. In terms of the time course of processing, inhibition deficits in the dyslexia group appeared during early-stage cognition selection and lasted through the response selection phase. Regarding the cerebral cortex locations, early-stage cognition selection was mainly located in the parietal region, while late-stage response selection was mainly located in the frontal and central regions. The results of our study may help further our understanding of the intrinsic causes of developmental dyslexia. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Event-related potentials elicited during working memory are altered in mild cognitive impairment.

    Science.gov (United States)

    López Zunini, Rocío A; Knoefel, Frank; Lord, Courtney; Dzuali, Fiatsogbe; Breau, Michael; Sweet, Lisa; Goubran, Rafik; Taler, Vanessa

    2016-11-01

    Persons with Mild Cognitive Impairment (MCI) can experience deficits in working memory. In the present study, we investigated working memory in persons with MCI and cognitively healthy older adults using event-related potentials (ERPs). Participants performed an n-back working memory task with baseline (0-back), low load (1-back), and high load (2-back) working memory conditions. MCI participants' performance was less accurate than that of healthy older adults in both the 1-back and 2-back conditions, and reaction times were longer in MCI than control participants in the 0-back, 1-back and 2-back conditions. ERP analyses revealed delayed P200 and N200 latencies and smaller P300 amplitudes in MCI relative to control participants in the 0-back, 1-back and 2-back conditions. Deterioration in working memory performance concomitant with marked electrophysiological alterations suggests that persons with MCI exhibit deficits in several cognitive processes that include early attention, stimulus discrimination and classification, and updating and manipulation of information held in working memory. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. The Potentiation of Associative Memory by Emotions: An Event-Related FMRI Study

    Directory of Open Access Journals (Sweden)

    David Luck

    2014-01-01

    Full Text Available Establishing associations between pieces of information is related to the medial temporal lobe (MTL. However, it remains unclear how emotions affect memory for associations and, consequently, MTL activity. Thus, this event-related fMRI study attempted to identify neural correlates of the influence of positive and negative emotions on associative memory. Twenty-five participants were instructed to memorize 90 pairs of standardized pictures during a scanned encoding phase. Each pair was composed of a scene and an unrelated object. Trials were neutral, positive, or negative as a function of the emotional valence of the scene. At the behavioral level, participants exhibited better memory retrieval for both emotional conditions relative to neutral trials. Within the right MTL, a functional dissociation was observed, with entorhinal activation elicited by emotional associations, posterior parahippocampal activation elicited by neutral associations, and hippocampal activation elicited by both emotional and neutral associations. In addition, emotional associations induced greater activation than neutral trials in the right amygdala. This fMRI study shows that emotions are associated with the performance improvement of associative memory, by enhancing activity in the right amygdala and the right entorhinal cortex. It also provides evidence for a rostrocaudal specialization within the MTL regarding the emotional valence of associations.

  19. Multi-objective optimal experimental designs for event-related fMRI studies.

    Science.gov (United States)

    Kao, Ming-Hung; Mandal, Abhyuday; Lazar, Nicole; Stufken, John

    2009-02-01

    In this article, we propose an efficient approach to find optimal experimental designs for event-related functional magnetic resonance imaging (ER-fMRI). We consider multiple objectives, including estimating the hemodynamic response function (HRF), detecting activation, circumventing psychological confounds and fulfilling customized requirements. Taking into account these goals, we formulate a family of multi-objective design criteria and develop a genetic-algorithm-based technique to search for optimal designs. Our proposed technique incorporates existing knowledge about the performance of fMRI designs, and its usefulness is shown through simulations. Although our approach also works for other linear combinations of parameters, we primarily focus on the case when the interest lies either in the individual stimulus effects or in pairwise contrasts between stimulus types. Under either of these popular cases, our algorithm outperforms the previous approaches. We also find designs yielding higher estimation efficiencies than m-sequences. When the underlying model is with white noise and a constant nuisance parameter, the stimulus frequencies of the designs we obtained are in good agreement with the optimal stimulus frequencies derived by Liu and Frank, 2004, NeuroImage 21: 387-400. In addition, our approach is built upon a rigorous model formulation.

  20. Event-related potential measures of gap detection threshold during natural sleep.

    Science.gov (United States)

    Muller-Gass, Alexandra; Campbell, Kenneth

    2014-08-01

    The minimum time interval between two stimuli that can be reliably detected is called the gap detection threshold. The present study examines whether an unconscious state, natural sleep affects the gap detection threshold. Event-related potentials were recorded in 10 young adults while awake and during all-night sleep to provide an objective estimate of this threshold. These subjects were presented with 2, 4, 8 or 16ms gaps occurring in 1.5 duration white noise. During wakefulness, a significant N1 was elicited for the 8 and 16ms gaps. N1 was difficult to observe during stage N2 sleep, even for the longest gap. A large P2 was however elicited and was significant for the 8 and 16ms gaps. Also, a later, very large N350 was elicited by the 16ms gap. An N1 and P2 was significant only for the 16ms gap during REM sleep. ERPs to gaps occurring in noise segments can therefore be successfully elicited during natural sleep. The gap detection threshold is similar in the waking and sleeping states. Crown Copyright © 2014. Published by Elsevier Ireland Ltd. All rights reserved.

  1. Test-retest reliability of infant event related potentials evoked by faces.

    Science.gov (United States)

    Munsters, N M; van Ravenswaaij, H; van den Boomen, C; Kemner, C

    2017-04-05

    Reliable measures are required to draw meaningful conclusions regarding developmental changes in longitudinal studies. Little is known, however, about the test-retest reliability of face-sensitive event related potentials (ERPs), a frequently used neural measure in infants. The aim of the current study is to investigate the test-retest reliability of ERPs typically evoked by faces in 9-10 month-old infants. The infants (N=31) were presented with neutral, fearful and happy faces that contained only the lower or higher spatial frequency information. They were tested twice within two weeks. The present results show that the test-retest reliability of the face-sensitive ERP components is moderate (P400 and Nc) to substantial (N290). However, there is low test-retest reliability for the effects of the specific experimental manipulations (i.e. emotion and spatial frequency) on the face-sensitive ERPs. To conclude, in infants the face-sensitive ERP components (i.e. N290, P400 and Nc) show adequate test-retest reliability, but not the effects of emotion and spatial frequency on these ERP components. We propose that further research focuses on investigating elements that might increase the test-retest reliability, as adequate test-retest reliability is necessary to draw meaningful conclusions on individual developmental trajectories of the face-sensitive ERPs in infants. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  2. Event-related potential correlates of serial-position effects during an elaborative memory test.

    Science.gov (United States)

    Rushby, Jacqueline A; Barry, Robert J; Johnstone, Stuart S

    2002-10-01

    Twenty undergraduate students participated in an elaborative learning test to evaluate the relationship between electrical brain activity and subsequently recalled and not-recalled words. Data collected from the midline (Fz, Cz, Pz) and lateral scalp sites (F3, F4, C3, C4, P3, P4) were analysed. The difference between event-related potentials (ERPs) elicited by subsequently recalled and not-recalled words, the ERP memory effect, was evaluated for each portion (primacy, plateau and recency) of the serial-position curve (SPC). We compared peak amplitudes for the P1, N1, P2, N400, P3 and frontal positive slow wave (FPSW) components. The electrophysiological data support the hypothesis that different mechanisms underlie primacy and recency effects during free recall paradigms. There was no support for the hypothesis that an association arises between memory and the FPSW when subjects utilise elaborative learning strategies. The P2 component predicted subsequent recall at the primacy portion of the SPC, and P1 predicted recall at the primacy and plateau portions of the curve. The findings suggest that the early positive components of the ERP (i.e. P1 and P2) are useful indices of the differential stimulus processing during elaborative learning which predicts later recall. Copyright 2002 Elsevier Science B.V.

  3. Evidence for Attentional Gradient in the Serial Position Memory Curve from Event-related Potentials

    Science.gov (United States)

    Azizian, Allen; Polich, John

    2009-01-01

    The occurrence of primacy versus recency effects in free recall is suggested to reflect either two distinct memory systems, or the operation of a single system that is modulated by allocation of attention and less vulnerable to interference. Behavioral and event-related brain potential (ERPs) measures were used to investigate the encoding substrates of the serial position curve and subsequent recall in young adults. Participants were instructed to remember lists of words consisting of 12 common nouns each presented once every 1.5 sec, with a recall signal following the last word to indicate that all remembered items should be written on paper. This procedure was repeated for 20 different word lists. Both performance and late ERP amplitudes reflected classic recall serial position effects. Greater recall and larger late positive component amplitudes were obtained for the primacy and recency items, with less recall and smaller amplitudes for the middle words. The late positive component was larger for recalled compared to unrecalled primacy items, but it did not differ between memory performance outcomes for the recency items. The close relationship between the enhanced amplitude and primacy retrieval supports the view that this positive component reflects one of a process series related to attentional gradient and encoding of events for storage in memory. Recency effects appear to index operations determined by the anticipation of the last stimulus presentation, which occurred for both recalled and unrecalled memory items. Theoretical implications are discussed. PMID:17892393

  4. High density event-related potential data acquisition in cognitive neuroscience.

    Science.gov (United States)

    Slotnick, Scott D

    2010-04-16

    Functional magnetic resonance imaging (fMRI) is currently the standard method of evaluating brain function in the field of Cognitive Neuroscience, in part because fMRI data acquisition and analysis techniques are readily available. Because fMRI has excellent spatial resolution but poor temporal resolution, this method can only be used to identify the spatial location of brain activity associated with a given cognitive process (and reveals virtually nothing about the time course of brain activity). By contrast, event-related potential (ERP) recording, a method that is used much less frequently than fMRI, has excellent temporal resolution and thus can track rapid temporal modulations in neural activity. Unfortunately, ERPs are under utilized in Cognitive Neuroscience because data acquisition techniques are not readily available and low density ERP recording has poor spatial resolution. In an effort to foster the increased use of ERPs in Cognitive Neuroscience, the present article details key techniques involved in high density ERP data acquisition. Critically, high density ERPs offer the promise of excellent temporal resolution and good spatial resolution (or excellent spatial resolution if coupled with fMRI), which is necessary to capture the spatial-temporal dynamics of human brain function.

  5. Event-related alpha perturbations related to the scaling of steering wheel corrections.

    Science.gov (United States)

    Brooks, Justin; Kerick, Scott

    2015-10-01

    Previously we derived a new measure relating the driver's steering wheel responses to the vehicle's heading error velocity. This measure, the relative steering wheel compensation (RSWC), changes at times coincident with an alerting stimulus, possibly representing shifts in control strategy as measured by a change in the gain between visual input and motor output. In the present study, we sought to further validate this novel measure by determining the relationship between the RSWC and electroencephalogram (EEG) activity in brain regions associated with sensorimotor transformation processes. These areas have been shown to exhibit event-related spectral perturbation (ERSP) in the alpha frequency band that occurs with the onset of corrective steering wheel maneuvers in response to vehicle perturbations. We hypothesized that these regions would show differential alpha activity depending on whether the RSWC was high or low, reflecting changes in gain between visual input and motor output. Interestingly, we find that low RSWC is associated with significantly less peak desynchronization than larger RSWC. In addition we demonstrate that these differences are not attributable to the amount the steering wheel is turned nor the heading error velocity independently. Collectively these results suggest that neural activity in these sensorimotor regions scales with alertness and may represent differential utilization of multisensory information to control the steering wheel. Published by Elsevier Inc.

  6. Inhibitory control in bilinguals and musicians: event related potential (ERP) evidence for experience-specific effects.

    Science.gov (United States)

    Moreno, Sylvain; Wodniecka, Zofia; Tays, William; Alain, Claude; Bialystok, Ellen

    2014-01-01

    Bilinguals and musicians exhibit behavioral advantages on tasks with high demands on executive functioning, particularly inhibitory control, but the brain mechanisms supporting these differences are unclear. Of key interest is whether these forms of experience influence cognition through similar or distinct information processing mechanisms. Here, we recorded event-related potentials (ERPs) in three groups - bilinguals, musicians, and controls - who completed a visual go-nogo task that involved the withholding of key presses to rare targets. Participants in each group achieved similar accuracy rates and responses times but the analysis of cortical responses revealed significant differences in ERP waveforms. Success in withholding a prepotent response was associated with enhanced stimulus-locked N2 and P3 wave amplitude relative to go trials. For nogo trials, there were altered timing-specific ERP differences and graded amplitude differences observed in the neural responses across groups. Specifically, musicians showed an enhanced early P2 response accompanied by reduced N2 amplitude whereas bilinguals showed increased N2 amplitude coupled with an increased late positivity wave relative to controls. These findings demonstrate that bilingualism and music training have differential effects on the brain networks supporting executive control over behavior.

  7. Modulation of early and late event-related potentials by emotion

    Directory of Open Access Journals (Sweden)

    Sarah J. Hart

    2012-11-01

    Full Text Available Although emotionally salient stimuli influence higher order information processing, the relative vulnerability of specific stages of cognitive processing to modulation by emotional input remains elusive. To test the temporal dynamics of emotional interference during executive function, we recorded event-related potentials while participants performed an effortful anticipation task with aversive emotional and neutral distracters. Participants were presented with a modified delayed Stroop task that dissociated the anticipation of an easier or more difficult task (instructional cues to attend to word versus color from the response to the Stroop stimulus, while aversive and neutral pictures were displayed during the delay period. Our results indicated a relative decrease in the amplitude of the contingent negative variation (CNV during aversive trials that was greater during the early anticipatory phase than during the later response preparation phase, and greater during (the more difficult color than word trials. During the initial stage of cue processing, there was also significant interaction between emotion and anticipatory difficulty on N1 amplitude, where emotional stimuli led to significantly enhanced negativity during color cues relative to word cues. These results suggest that earlier processes of orientation and effortful anticipation may reflect executive engagement that is influenced by emotional interference while later phases of response preparation may be modulated by emotional interference regardless of anticipatory difficulty.

  8. Olfactory short-term memory encoding and maintenance - an event-related potential study.

    Science.gov (United States)

    Lenk, Steffen; Bluschke, Annet; Beste, Christian; Iannilli, Emilia; Rößner, Veit; Hummel, Thomas; Bender, Stephan

    2014-09-01

    This study examined whether the memory encoding and short term maintenance of olfactory stimuli is associated with neurophysiological activation patterns which parallel those described for sensory modalities such as vision and auditory. We examined olfactory event-related potentials in an olfactory change detection task in twenty-four healthy adults and compared the measured activation to that found during passive olfactory stimulation. During the early olfactory post-processing phase, we found a sustained negativity over bilateral frontotemporal areas in the passive perception condition which was enhanced in the active memory task. There was no significant lateralization in either experimental condition. During the maintenance interval at the end of the delay period, we still found sustained activation over bilateral frontotemporal areas which was more negative in trials with correct - as compared to incorrect - behavioural responses. This was complemented by a general significantly stronger frontocentral activation. Summarizing, we were able to show that olfactory short term memory involves a parallel sequence of activation as found in other sensory modalities. In addition to olfactory-specific frontotemporal activations in the memory encoding phase, we found slow cortical potentials over frontocentral areas during the memory maintenance phase indicating the activation of a supramodal memory maintenance system. These findings could represent the neurophysiological underpinning of the 'olfactory flacon', the olfactory counter-part to the visual sketchpad and phonological loop embedded in Baddeley's working memory model. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Visual image retention does not contribute to modulation of event-related potentials by mental rotation.

    Science.gov (United States)

    Riečanský, Igor; Tomova, Livia; Katina, Stanislav; Bauer, Herbert; Fischmeister, Florian Ph S; Lamm, Claus

    2013-11-01

    Rotation of a visual image in mind is associated with a slow posterior negative deflection of the event-related potential (ERP), termed rotation-related negativity (RRN). Retention of a visual image in short-term memory is also associated with a slow posterior negative ERP, termed negative slow wave (NSW). We tested whether short-term memory retention, indexed by the NSW, contributes to the RRN. ERPs were recorded in the same subjects in two tasks, a mental rotation task, eliciting the RRN, and a visual short-term memory task, eliciting the NSW. Over both right and left parietal scalp, no association was found between the NSW and the RRN amplitudes. Furthermore, adjusting for the effect of the NSW had no influence on a significant association between the RRN amplitude and response time, an index of mental rotation performance. Our data indicate that the RRN reflects manipulation of a visual image but not its retention in short-term memory. Copyright © 2013 Elsevier Inc. All rights reserved.

  10. Gender differences in memory processing of female facial attractiveness: evidence from event-related potentials.

    Science.gov (United States)

    Zhang, Yan; Wei, Bin; Zhao, Peiqiong; Zheng, Minxiao; Zhang, Lili

    2016-06-01

    High rates of agreement in the judgment of facial attractiveness suggest universal principles of beauty. This study investigated gender differences in recognition memory processing of female facial attractiveness. Thirty-four Chinese heterosexual participants (17 females, 17 males) aged 18-24 years (mean age 21.63 ± 1.51 years) participated in the experiment which used event-related potentials (ERPs) based on a study-test paradigm. The behavioral data results showed that both men and women had significantly higher accuracy rates for attractive faces than for unattractive faces, but men reacted faster to unattractive faces. Gender differences on ERPs showed that attractive faces elicited larger early components such as P1, N170, and P2 in men than in women. The results indicated that the effects of recognition bias during memory processing modulated by female facial attractiveness are greater for men than women. Behavioral and ERP evidences indicate that men and women differ in their attentional adhesion to attractive female faces; different mating-related motives may guide the selective processing of attractive men and women. These findings establish a contribution of gender differences on female facial attractiveness during memory processing from an evolutionary perspective.

  11. Event related desynchronization-modulated functional electrical stimulation system for stroke rehabilitation: A feasibility study

    Directory of Open Access Journals (Sweden)

    Takahashi Mitsuru

    2012-08-01

    Full Text Available Abstract Background We developed an electroencephalogram-based brain computer interface system to modulate functional electrical stimulation (FES to the affected tibialis anterior muscle in a stroke patient. The intensity of FES current increased in a stepwise manner when the event-related desynchronization (ERD reflecting motor intent was continuously detected from the primary cortical motor area. Methods We tested the feasibility of the ERD-modulated FES system in comparison with FES without ERD modulation. The stroke patient who presented with severe hemiparesis attempted to perform dorsiflexion of the paralyzed ankle during which FES was applied either with or without ERD modulation. Results After 20 minutes of training, the range of movement at the ankle joint and the electromyography amplitude of the affected tibialis anterior muscle were significantly increased following the ERD-modulated FES compared with the FES alone. Conclusions The proposed rehabilitation technique using ERD-modulated FES for stroke patients was feasible. The system holds potentials to improve the limb function and to benefit stroke patients.

  12. Orthographic combinability and phonological consistency effects in reading Chinese phonograms: an event-related potential study.

    Science.gov (United States)

    Hsu, Chun-Hsien; Tsai, Jie-Li; Lee, Chia-Ying; Tzeng, Ovid J-L

    2009-01-01

    In this study, event-related potentials (ERPs) were used to trace the temporal dynamics of phonological consistency and phonetic combinability in the reading of Chinese phonograms. The data showed a significant consistency-by-combinability interaction at N170. High phonetic combinability characters elicited greater negativity at N170 than did low phonetic combinability characters, and the combinability effect was only found in the reading of high consistency characters. The results support the phonological mapping hypothesis of the reading-related N170 effect and suggest that the earlier stages of visual word recognition are shaped by the mapping of orthography to phonology even in Chinese. Moreover, our data revealed both consistency and combinability effects at P200 and N400, accounted for by the two-stage framework for visual word recognition. That is, characters with high combinability or high consistency facilitated the earlier stages of orthographic or phonological processing which were due to increased activation at the perceptual level; consequently, less positive P200 was demonstrated. In the later stages, high combinability or high consistency characters were associated with a larger semantic neighborhood, which increased semantic competition and exaggerated the N400 effect. These data support the assumption of radical-based inputs proposed by the lexical constituent model. However, the phonetic consistency effects found at N170 and P200 cannot be reconciled with the current framework of the lexical constituent model. A possible revision will be discussed.

  13. Exploring consciousness in emotional face decoding: an event-related potential analysis.

    Science.gov (United States)

    Balconi, Michela

    2006-05-01

    The author analyzed the role of consciousness in emotional face comprehension. The author recorded psychophysiological measures of event-related potentials (ERPs), elicited by supraliminal and subliminal stimuli when participants viewed emotional facial expressions of 4 emotions or neutral stimuli. The author analyzed an ERP emotion-specific effect (N200 peak variation; temporal interval was 180-300 ms poststimulus) in terms of peak amplitude and latency variables. The results indicated 4 important findings. First, there was an emotional-specific ERP deflection only for emotional stimuli, not for neutral stimuli. Second, the unaware information processing was quite similar to that of aware in terms of peak morphology, but not in terms of latency. In fact, unconscious stimulation produced a more delayed peak variation than did conscious stimulation. Third, valence of facial stimulus (positive or negative) was supraliminally and subliminally decoded because it was showed by differences of peak deflection between negative high arousing (fear and anger) and low arousing (happiness, sadness, and neutral) stimuli. Finally, the author found a more posterior distribution of ERP as a function of emotional content of the stimulus. Cortical lateralization (right or left) was not correlated to conscious or unconscious stimulation. The author discussed the functional significance of her results in terms of supraliminal and subliminal conditions.

  14. Do Event-Related Evoked Potentials Reflect Apathy Tendency and Motivation?

    Science.gov (United States)

    Takayoshi, Hiroyuki; Onoda, Keiichi; Yamaguchi, Shuhei

    2018-01-01

    Apathy is a mental state of diminished motivation. Although the reward system as the foundation of the motivation in the human brain has been studied extensively with neuroimaging techniques, the electrophysiological correlates of motivation and apathy have not been fully explored. Thus, in 14 healthy volunteers, we examined whether event-related evoked potentials (ERP) obtained during a simple number discrimination task with/without rewards reflected apathy tendency and a reward-dependent tendency, which were assessed separately using the apathy scale and the temperament and character inventory (TCI). Participants were asked to judge the size of a number, and received feedback based on their performance in each trial. The P3 amplitudes related to the feedback stimuli increased only in the reward condition. Furthermore, the P2 amplitudes related to the negative feedback stimuli in the reward condition had a positive correlation with the reward-dependent tendency in TCI, whereas the P3 amplitudes related to the positive feedback stimuli had a negative correlation with the apathy score. Our result suggests that the P2 and P3 ERPs to reward-related feedback stimuli are modulated in a distinctive manner by the motivational reward dependence and apathy tendency, and thus the current paradigm may be useful for investigating the brain activity associated with motivation.

  15. An event-related potential study on cross-modal conversion of Chinese characters.

    Science.gov (United States)

    Wu, Qiuyan; Deng, Yuan

    2011-10-03

    In the current study, we explored the effects of ERPs (event-related potentials), related to the cross-modal transfer from visual input to phonological retrieval. Using Chinese single-character words, participants were asked to make orthographic (intra-modal) and phonological (cross-modal) responses to visually presented words. By comparing the cross-modal and intra-modal tasks, we found that both tasks evoke similar activity in the early stage of lexical processing, showing the same pattern of N2 effect (a negative component peaking around 220 ms) and P2 effect (a positive component peaking around 270 ms). However, the effect of the task was significant in the 300-700 ms time window, consisting of a frontal-based N400 effect and a parietal based late positive component (LPC) effect. These findings suggest that the frontal-based N400 is associated with orthography-to-phonology mapping in Chinese, and the LPC reflects greater requirement of maintaining retrieved information in working memory for the cross-modal processing. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  16. Interactions between mood and the structure of semantic memory: event-related potentials evidence.

    Science.gov (United States)

    Pinheiro, Ana P; del Re, Elisabetta; Nestor, Paul G; McCarley, Robert W; Gonçalves, Óscar F; Niznikiewicz, Margaret

    2013-06-01

    Recent evidence suggests that affect acts as modulator of cognitive processes and in particular that induced mood has an effect on the way semantic memory is used on-line. We used event-related potentials (ERPs) to examine affective modulation of semantic information processing under three different moods: neutral, positive and negative. Fifteen subjects read 324 pairs of sentences, after mood induction procedure with 30 pictures of neutral, 30 pictures of positive and 30 pictures of neutral valence: 108 sentences were read in each mood induction condition. Sentences ended with three word types: expected words, within-category violations, and between-category violations. N400 amplitude was measured to the three word types under each mood induction condition. Under neutral mood, a congruency (more negative N400 amplitude for unexpected relative to expected endings) and a category effect (more negative N400 amplitude for between- than to within-category violations) were observed. Also, results showed differences in N400 amplitude for both within- and between-category violations as a function of mood: while positive mood tended to facilitate the integration of unexpected but related items, negative mood made their integration as difficult as unexpected and unrelated items. These findings suggest the differential impact of mood on access to long-term semantic memory during sentence comprehension.

  17. Event-related potentials during word mapping to object shape predict toddlers' vocabulary size.

    Science.gov (United States)

    Borgström, Kristina; Torkildsen, Janne von Koss; Lindgren, Magnus

    2015-01-01

    What role does attention to different object properties play in early vocabulary development? This longitudinal study using event-related potentials in combination with behavioral measures investigated 20- and 24-month-olds' (n = 38; n = 34; overlapping n = 24) ability to use object shape and object part information in word-object mapping. The N400 component was used to measure semantic priming by images containing shape or detail information. At 20 months, the N400 to words primed by object shape varied in topography and amplitude depending on vocabulary size, and these differences predicted productive vocabulary size at 24 months. At 24 months, when most of the children had vocabularies of several hundred words, the relation between vocabulary size and the N400 effect in a shape context was weaker. Detached object parts did not function as word primes regardless of age or vocabulary size, although the part-objects were identified behaviorally. The behavioral measure, however, also showed relatively poor recognition of the part-objects compared to the shape-objects. These three findings provide new support for the link between shape recognition and early vocabulary development.

  18. Event-related potentials during word mapping to object shape predict toddlers’ vocabulary size

    Directory of Open Access Journals (Sweden)

    Kristina eBorgström

    2015-02-01

    Full Text Available What role does attention to different object properties play in early vocabulary development? This longitudinal study using event-related potentials in combination with behavioral measures investigated 20- and 24-month-olds’ (n = 38; n = 34; overlapping n = 24 ability to use object shape and object part information in word-object mapping. The N400 component was used to measure semantic priming by images containing shape or detail information. At 20 months, the N400 to words primed by object shape varied in topography and amplitude depending on vocabulary size, and these differences predicted productive vocabulary size at 24 months. At 24 months, when most of the children had vocabularies of several hundred words, the relation between vocabulary size and the N400 effect in a shape context was weaker. Detached object parts did not function as word primes regardless of age or vocabulary size, although the part-objects were identified behaviorally. The behavioral measure, however, also showed relatively poor recognition of the part-objects compared to the shape-objects. These three findings provide new support for the link between shape recognition and early vocabulary development.

  19. On the violation of causal, emotional, and locative inferences: An event-related potentials study.

    Science.gov (United States)

    Rodríguez-Gómez, Pablo; Sánchez-Carmona, Alberto; Smith, Cybelle; Pozo, Miguel A; Hinojosa, José A; Moreno, Eva M

    2016-07-01

    Previous event-related potential studies have demonstrated the online generation of inferences during reading for comprehension tasks. The present study contrasted the brainwave patterns of activity to the fulfilment or violation of various types of inferences (causal, emotional, locative). Relative to inference congruent sentence endings, a typical centro-parietal N400 was elicited for the violation of causal and locative inferences. This N400 effect was initially absent for emotional inferences, most likely due to their lower cloze probability. Between 500 and 750ms, a larger frontal positivity (pN400FP) was elicited by inference incongruent sentence endings in the causal condition. In emotional sentences, both inference congruent and incongruent endings exerted this frontally distributed late positivity. For the violation of locative inferences, the larger positivity was only marginally significant over left posterior scalp locations. Thus, not all inference eliciting sentences evoked a similar pattern of ERP responses. We interpret and discuss our results in line with recent views on what the N400, the P600 and the pN400FP brainwave potentials index. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. An Event-Related Potential Study on the Effects of Cannabis on Emotion Processing.

    Directory of Open Access Journals (Sweden)

    Lucy J Troup

    Full Text Available The effect of cannabis on emotional processing was investigated using event-related potential paradigms (ERPs. ERPs associated with emotional processing of cannabis users, and non-using controls, were recorded and compared during an implicit and explicit emotional expression recognition and empathy task. Comparisons in P3 component mean amplitudes were made between cannabis users and controls. Results showed a significant decrease in the P3 amplitude in cannabis users compared to controls. Specifically, cannabis users showed reduced P3 amplitudes for implicit compared to explicit processing over centro-parietal sites which reversed, and was enhanced, at fronto-central sites. Cannabis users also showed a decreased P3 to happy faces, with an increase to angry faces, compared to controls. These effects appear to increase with those participants that self-reported the highest levels of cannabis consumption. Those cannabis users with the greatest consumption rates showed the largest P3 deficits for explicit processing and negative emotions. These data suggest that there is a complex relationship between cannabis consumption and emotion processing that appears to be modulated by attention.

  1. Event-related potentials reflecting the processing of phonological constraint violations.

    Science.gov (United States)

    Domahs, Ulrike; Kehrein, Wolfgang; Knaus, Johannes; Wiesel, Richard; Schlesewsky, Matthias

    2009-01-01

    How are violations of phonological constraints processed in word comprehension? The present article reports the results of an event-related potentials (ERP) study on a phonological constraint of German that disallows identical segments within a syllable or word (CC(i)VC(i)). We examined three types of monosyllabic late positive CCVC words: (a) existing words [see text], (b) wellformed novel words [see text] and component (c) illformed novel words [see text] as instances of Obligatory Contour Principle non-word (OCP) violations. Wellformed and illformed novel words evoked an N400 effect processing in comparison to existing words. In addition, illformed words produced an enhanced late posterior positivity effect compared to wellformed novel words. obligatory contour Our findings support the well-known observation that novel words evoke principle higher costs in lexical integration (reflected by N400 effects). Crucially, modulations of a late positive component (LPC) show that violations of phonological phonotactic constraints influence later stages of cognitive processing even constraints when stimuli have already been detected as non-existing. Thus, the comparison of electrophysiological effects evoked by the two types of non-existing words reveals the stages at which phonologically based structural wellformedness comes into play during word processing.

  2. Behavioral and neural correlates of emotional intelligence: an event-related potentials (ERP) study.

    Science.gov (United States)

    Raz, Sivan; Dan, Orrie; Arad, Hen; Zysberg, Leehu

    2013-08-14

    The present study was aimed at identifying potential behavioral and neural correlates of emotional intelligence (EI) by using scalp-recorded Event-Related Potentials (ERPs). EI levels were defined according to both self-report questionnaire and a performance-based test. We identified ERP correlates of emotional processing by comparing ERPs elicited in trials using pleasant, neutral and unpleasant pictures. The effects of these emotion-inducing pictures were then compared across groups with low and high EI levels. Behavioral results revealed a significant valence×EI group interaction effect since valence ratings were lower for unpleasant pictures and higher for pleasant pictures in the high EI group compared with the low EI group. The groups did not differ with respect to neutral picture ratings. The ERP results indicate that participants with high EI exhibited significantly greater mean amplitudes of the P2 (200-300ms post-stimulus) and P3 (310-450ms post-stimulus) ERP components in response to emotional and neutral pictures, at posterior-parietal as well as at frontal scalp locations. This may suggest greater recruitment of resources to process all emotional and non-emotional stimuli at early and late processing stages among individuals with higher EI. The present study also underscores the usefulness of ERP methodology as a sensitive measure for the study of emotional stimuli processing in the research field of EI. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. High contextual sensitivity of metaphorical expressions and gesture blending: A video event-related potential design.

    Science.gov (United States)

    Ibáñez, Agustín; Toro, Pablo; Cornejo, Carlos; Urquina, Hugo; Hurquina, Hugo; Manes, Facundo; Weisbrod, Matthias; Schröder, Johannes

    2011-01-30

    Human communication in a natural context implies the dynamic coordination of contextual clues, paralinguistic information and literal as well as figurative language use. In the present study we constructed a paradigm with four types of video clips: literal and metaphorical expressions accompanied by congruent and incongruent gesture actions. Participants were instructed to classify the gesture accompanying the expression as congruent or incongruent by pressing two different keys while electrophysiological activity was being recorded. We compared behavioral measures and event related potential (ERP) differences triggered by the gesture stroke onset. Accuracy data showed that incongruent metaphorical expressions were more difficult to classify. Reaction times were modulated by incongruent gestures, by metaphorical expressions and by a gesture-expression interaction. No behavioral differences were found between the literal and metaphorical expressions when the gesture was congruent. N400-like and LPC-like (late positive complex) components from metaphorical expressions produced greater negativity. The N400-like modulation of metaphorical expressions showed a greater difference between congruent and incongruent categories over the left anterior region, compared with the literal expressions. More importantly, the literal congruent as well as the metaphorical congruent categories did not show any difference. Accuracy, reaction times and ERPs provide convergent support for a greater contextual sensitivity of the metaphorical expressions. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  4. Short-Term Effects of Prosocial Video Games on Aggression: An Event-Related Potential Study

    Directory of Open Access Journals (Sweden)

    Yanling eLiu

    2015-07-01

    Full Text Available Previous research has shown that exposure to violent video games increases aggression, whereas exposure to prosocial video games can reduce aggressive behavior. However, little is known about the neural correlates of these behavioral effects. This work is the first to investigate the electrophysiological features of the relationship between playing a prosocial video game and inhibition of aggressive behavior. Forty-nine subjects played either a prosocial or a neutral video game for 20 minutes, then participated in an event-related potential (ERP experiment based on an oddball paradigm and designed to test electrophysiological responses to prosocial and violent words. Finally, subjects completed a competitive reaction time task (CRTT, which is based on Taylor’s Aggression Paradigm and measures both reaction time and noise intensity preference as indices of aggressive behavior. The results show that the prosocial video game group (compared to the neutral video game group displayed smaller P300 amplitudes, were more accurate in distinguishing violent words, and were less aggressive as evaluated by the CRTT (noise intensity preference. A mediation analysis shows that the P300 amplitude evoked by violent words partially mediates the relationship between type of video game and subsequent aggressive behavior. The results support theories based on the General Learning Model. We provide converging behavioral and neural evidence that exposure to prosocial media may reduce aggression.

  5. Event-related brain potentials for goal-related power grips.

    Directory of Open Access Journals (Sweden)

    Jan Westerholz

    Full Text Available Recent research has shown that neurophysiological activation during action planning depends on the orientation to initial or final action goals for precision grips. However, the neural signature for a distinct class of grasping, power grips, is still unknown. The aim of the present study was to differentiate between cerebral activity, by means of event-related potentials (ERPs, and its temporal organization during power grips executed with an emphasis on either the initial or final parts of movement sequences. In a grasp and transportation task, visual cues emphasized either the grip (the immediate goal or the target location (the final goal. ERPs differed between immediate and final goal-cued conditions, suggesting different means of operation dependent on goal-relatedness. Differences in mean amplitude occurred earlier for power grips than for recently reported precision grips time-locked to grasping over parieto-occipital areas. Time-locked to final object placement, differences occurred within a similar time window for power and precision grips over frontal areas. These results suggest that a parieto-frontal network of activation is of crucial importance for grasp planning and execution. Our results indicate that power grip preparation and execution for goal-related actions are controlled by similar neural mechanisms as have been observed during precision grips, but with a distinct temporal pattern.

  6. Resolving the orthographic ambiguity during visual word recognition in Arabic: an event-related potential investigation

    Science.gov (United States)

    Taha, Haitham; Khateb, Asaid

    2013-01-01

    The Arabic alphabetical orthographic system has various unique features that include the existence of emphatic phonemic letters. These represent several pairs of letters that share a phonological similarity and use the same parts of the articulation system. The phonological and articulatory similarities between these letters lead to spelling errors where the subject tends to produce a pseudohomophone (PHw) instead of the correct word. Here, we investigated whether or not the unique orthographic features of the written Arabic words modulate early orthographic processes. For this purpose, we analyzed event-related potentials (ERPs) collected from adult skilled readers during an orthographic decision task on real words and their corresponding PHw. The subjects' reaction times (RTs) were faster in words than in PHw. ERPs analysis revealed significant response differences between words and the PHw starting during the N170 and extending to the P2 component, with no difference during processing steps devoted to phonological and lexico-semantic processing. Amplitude and latency differences were found also during the P6 component which peaked earlier for words and where source localization indicated the involvement of the classical left language areas. Our findings replicate some of the previous findings on PHw processing and extend them to involve early orthographical processes. PMID:24348367

  7. Mastication accelerates Go/No-go decisional processing: An event-related potential study.

    Science.gov (United States)

    Sakamoto, Kiwako; Nakata, Hiroki; Yumoto, Masato; Sadato, Norihiro; Kakigi, Ryusuke

    2015-11-01

    The purpose of the present study was to investigate the effect of mastication on Go/No-go decisional processing using event-related potentials (ERPs). Thirteen normal subjects underwent seven sessions of a somatosensory Go/No-go paradigm for approximately 4min; Pre, and Post 1, 2, 3, 4, 5, and 6. The Control condition included the same seven sessions. The RT and standard deviation were recorded, and the peak amplitude and latency of the N140 and P300 components were analyzed. The RT was significantly shorter in Mastication than in Control at Post 1-3 and 4-6. The peak latency of N140 was earlier in Mastication than in Control at Post 4-6. The latency of N140 was shortened by repeated sessions in Mastication, but not by those in Control. The peak latency of P300 was significantly shorter in Mastication than in Control at Post 4-6. The peak latency of P300 was significantly longer in Control with repeated sessions, but not in Mastication. These results suggest that mastication may influence response execution processing in Go trials, as well as response inhibition processing in No-go trials. Mastication accelerated Go/No-go decisional processing in the human brain. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  8. Impaired Early Attentional Processes in Parkinson's Disease: A High-Resolution Event-Related Potentials Study.

    Directory of Open Access Journals (Sweden)

    Perrine Bocquillon

    Full Text Available The selection of task-relevant information requires both the focalization of attention on the task and resistance to interference from irrelevant stimuli. A previous study using the P3 component of the event-related potentials suggested that a reduced ability to resist interference could be responsible for attention disorders at early stages of Parkinson's disease (PD, with a possible role of the dorsolateral prefrontal cortex (DLPFC.Our objective was to better determine the origin of this impairment, by studying an earlier ERP component, the N2, and its subcomponents, as they reflect early inhibition processes and as they are known to have sources in the anterior cingulate cortex (ACC, which is involved together with the DLPFC in inhibition processes. Fifteen early-stage PD patients and 15 healthy controls (HCs performed a three-stimulus visual oddball paradigm, consisting in detecting target inputs amongst standard stimuli, while resisting interference from distracter ones. A 128-channel electroencephalogram was recorded during this task and the generators of the N2 subcomponents were identified using standardized weighted low-resolution electromagnetic tomography (swLORETA.PD patients displayed fewer N2 generators than HCs in both the DLPFC and the ACC, for all types of stimuli. In contrast to controls, PD patients did not show any differences between their generators for different N2 subcomponents.Our data suggest that impaired inhibition in PD results from dysfunction of the DLPFC and the ACC during the early stages of attentional processes.

  9. Impaired Empathy Processing in Individuals with Internet Addiction Disorder: An Event-Related Potential Study

    Directory of Open Access Journals (Sweden)

    Can Jiao

    2017-10-01

    Full Text Available Internet addiction disorder (IAD is associated with deficits in social communication and avoidance of social contact. It has been hypothesized that people with IAD may have an impaired capacity for empathy. The purpose of the current study was to examine the processing of empathy for others’ pain in IADs. Event-related potentials produced in response to pictures showing others in painful and non-painful situations were recorded in 16 IAD subjects and 16 healthy controls (HCs. The N1, P2, N2, P3, and late positive potential components were compared between the two groups. Robust picture × group interactions were observed for N2 and P3. The painful pictures elicited larger N2 and P3 amplitudes than the non-painful pictures did only in the HC group but not in the IAD group. The results of this study suggest that both of the early automatic and of the later cognitive processes of pain empathy may be impaired in IADs. This study provides psychophysical evidence of empathy deficits in association with IAD. Further studies combining multidimensional measurements of empathy are needed to confirm these findings.

  10. Post-Decision Wagering Affects Metacognitive Awareness of Emotional Stimuli: An Event Related Potential Study.

    Directory of Open Access Journals (Sweden)

    Michał Wierzchoń

    Full Text Available The present research investigated metacognitive awareness of emotional stimuli and its psychophysiological correlates. We used a backward masking task presenting participants with fearful or neutral faces. We asked participants for face discrimination and then probed their metacognitive awareness with confidence rating (CR and post-decision wagering (PDW scales. We also analysed psychophysiological correlates of awareness with event-related potential (ERP components: P1, N170, early posterior negativity (EPN, and P3. We have not observed any differences between PDW and CR conditions in the emotion identification task. However, the "aware" ratings were associated with increased accuracy performance. This effect was more pronounced in PDW, especially for fearful faces, suggesting that emotional stimuli awareness may be enhanced by monetary incentives. EEG analysis showed larger N170, EPN and P3 amplitudes in aware compared to unaware trials. It also appeared that both EPN and P3 ERP components were more pronounced in the PDW condition, especially when emotional faces were presented. Taken together, our ERP findings suggest that metacognitive awareness of emotional stimuli depends on the effectiveness of both early and late visual information processing. Our study also indicates that awareness of emotional stimuli can be enhanced by the motivation induced by wagering.

  11. Age difference in numeral recognition and calculation: an event-related potential study.

    Science.gov (United States)

    Xuan, Dong; Wang, Suhong; Yang, Yilin; Meng, Ping; Xu, Feng; Yang, Wen; Sheng, Wei; Yang, Yuxia

    2007-01-01

    In this study, we investigated the age difference in numeral recognition and calculation in one group of school-aged children (n = 38) and one of undergraduate students (n = 26) using the event-related potential (ERP) methods. Consistent with previous reports, the age difference was significant in behavioral results. Both numeral recognition and calculation elicited a negativity peaking at about 170-280 ms (N2) and a positivity peaking at 200-470 ms (pSW) in raw ERPs, and a difference potential (dN3) between 360 and 450 ms. The difference between the two age groups indicated that more attention resources were devoted to arithmetical tasks in school-aged children, and that school-aged children and undergraduate students appear to use different strategies to solve arithmetical problems. The analysis of frontal negativity suggested that numeral recognition and mental calculation impose greater load on working memory and executive function in schoolchildren than in undergraduate students. The topography data determined that the parietal regions were responsible for arithmetical function in humans, and there was an age-related difference in the area of cerebral activation.

  12. The arithmetic problem size effect in children: an event-related potential study

    Directory of Open Access Journals (Sweden)

    Leen eVan Beek

    2014-09-01

    Full Text Available This study used for the first time event-related potentials (ERPs to examine the well-known arithmetic problem size effect in children. The electrophysiological correlates of this problem size effect have been well documented in adults, but such information in children is lacking. In the present study, 22 typically developing 12-year-olds were asked to solve single-digit addition problems of small (sum ≤ 10 and large problem size (sum > 10 and to speak the solution into a voice key while ERPs were recorded. Children displayed similar early and late components compared to previous adult studies on the problem size effect. There was no effect of problem size on the early components P1, N1 and P2. The peak amplitude of the N2 component showed more negative potentials on left and right anterior electrodes for large additions compared to small additions, which might reflect differences in attentional and working memory resources between large and small problems. The mean amplitude of the late positivity component (LPC, which follows the N2, was significantly larger for large than for small additions at right parieto-occipital electrodes, in line with previous adult data. The ERPs of the problem size effect during arithmetic might be a useful neural marker for future studies on fact retrieval impairments in children with mathematical difficulties.

  13. Sleep inertia and autonomic effects on post-nap P300 event-related potential.

    Science.gov (United States)

    Takahashi, M; Arito, H

    1998-10-01

    The objective of this study was to examine the relationship between post-nap measures of alertness and performance and non-rapid eye movement (NREM) sleep and parasympathetic activity during brief naps. Thirty healthy subjects were randomly assigned to no-nap, 15-min, and 45-min nap conditions after normal home sleep at prior night. Each nap was taken after lunch and monitored by electroencephalogram (EEG), electromyogram, electrooculogram, and electrocardiogram (ECG). Deep NREM sleep was quantified by EEG delta power density and the parasympathetic activity was quantified by the ECG high-frequency (HF) component of R-R interval variability during the 15- and 45-min naps. The P300 event-related potential, subjective sleepiness, and performance on a 90-min English transcription task were measured 30 min and 3 hr after the naps and tested for their association with the EEG and ECG measures. A positive correlation was obtained between EEG delta power density during the naps and P300 latency 30 min after the naps (r = 0.476, p sleep inertia prolongs the P300 latency immediately after the naps, and that the parasympathetic predominance during the naps may improve subsequent alertness as assessed by the shortened P300 latency 3 hr after the naps.

  14. Direct effects of prismatic lenses on visuomotor control: an event-related functional MRI study.

    Science.gov (United States)

    Danckert, James; Ferber, Susanne; Goodale, Melvyn A

    2008-10-01

    Exposure to prisms has long been used to explore the control of visually guided actions primarily because adaptation requires the recalibration of misaligned reference frames due to perturbed visual input (i.e. eye-in-head and hand-centered reference frames must be realigned). To date, the only neuroimaging study to explore the direct effects of prisms on pointing used positron emission tomography and found increased activation only in right parietal cortex. We used event-related functional MRI to examine the effects of prisms on visuomanual pointing. Results demonstrated changes in activity in the anterior cingulate, the anterior intraparietal region and in a medial region of the right cerebellum. Specifically, activity in these regions was higher for the first few pointing trials made while viewing targets through prisms when directly contrasted to the last few trials. These results highlight that a more extensive network of cortical and cerebellar regions is involved in recalibrating visuomotor commands in the face of perturbed visual input.

  15. Random Number Generation and Executive Functions in Parkinson's Disease: An Event-Related Brain Potential Study.

    Science.gov (United States)

    Münte, Thomas F; Joppich, Gregor; Däuper, Jan; Schrader, Christoph; Dengler, Reinhard; Heldmann, Marcus

    2015-01-01

    The generation of random sequences is considered to tax executive functions and has been reported to be impaired in Parkinson's disease (PD) previously. To assess the neurophysiological markers of random number generation in PD. Event-related potentials (ERP) were recorded in 12 PD patients and 12 age-matched normal controls (NC) while either engaging in random number generation (RNG) by pressing the number keys on a computer keyboard in a random sequence or in ordered number generation (ONG) necessitating key presses in the canonical order. Key presses were paced by an external auditory stimulus at a rate of 1 tone every 1800 ms. As a secondary task subjects had to monitor the tone-sequence for a particular target tone to which the number "0" key had to be pressed. This target tone occurred randomly and infrequently, thus creating a secondary oddball task. Behaviorally, PD patients showed an increased tendency to count in steps of one as well as a tendency towards repetition avoidance. Electrophysiologically, the amplitude of the P3 component of the ERP to the target tone of the secondary task was reduced during RNG in PD but not in NC. The behavioral findings indicate less random behavior in PD while the ERP findings suggest that this impairment comes about, because attentional resources are depleted in PD.

  16. Inhibitory control in bilinguals and musicians: event related potential (ERP evidence for experience-specific effects.

    Directory of Open Access Journals (Sweden)

    Sylvain Moreno

    Full Text Available Bilinguals and musicians exhibit behavioral advantages on tasks with high demands on executive functioning, particularly inhibitory control, but the brain mechanisms supporting these differences are unclear. Of key interest is whether these forms of experience influence cognition through similar or distinct information processing mechanisms. Here, we recorded event-related potentials (ERPs in three groups - bilinguals, musicians, and controls - who completed a visual go-nogo task that involved the withholding of key presses to rare targets. Participants in each group achieved similar accuracy rates and responses times but the analysis of cortical responses revealed significant differences in ERP waveforms. Success in withholding a prepotent response was associated with enhanced stimulus-locked N2 and P3 wave amplitude relative to go trials. For nogo trials, there were altered timing-specific ERP differences and graded amplitude differences observed in the neural responses across groups. Specifically, musicians showed an enhanced early P2 response accompanied by reduced N2 amplitude whereas bilinguals showed increased N2 amplitude coupled with an increased late positivity wave relative to controls. These findings demonstrate that bilingualism and music training have differential effects on the brain networks supporting executive control over behavior.

  17. Cognitive event-related potentials and brain magnetic resonance imaging in HTLV-1 associated myelopathy (HAM).

    Science.gov (United States)

    Fukushima, T; Ikeda, T; Uyama, E; Uchino, M; Okabe, H; Ando, M

    1994-10-01

    Auditory and visual cognitive event-related potentials (ERPs) were investigated in 14 patients with HTLV-1 associated myelopathy (HAM) and in 36 normal controls. In the HAM patients, the latencies of P300 and N200 by the auditory tone method were significantly delayed, and N100 by the auditory click method was significantly delayed in latency. No abnormal ERP components were observed with visual methods. While these auditory abnormal ERPs were present in the HAM patients, there was no evidence of visual abnormal ERPs. Abnormal lesions on the white matter were evident at magnetic resonance imaging (MRI) in 6 (75%) of 8 patients. There was no correlation between MRI lesions and the abnormalities of ERPs, but there was a significant correlation between bifrontal index on MRI and P300 amplitudes at Cz and Pz sites by auditory tone method. In one patient, atrophy of bilateral parietal lobes was seen on MRI and P300 latencies delayed using various methods. Therefore, the possibility that electrophysiological cognitive impairment in patients with HAM is related to brain atrophy rather than to white matter lesions requires attention.

  18. ERPLAB: An Open-Source Toolbox for the Analysis of Event-Related Potentials

    Directory of Open Access Journals (Sweden)

    Javier eLopez-Calderon

    2014-04-01

    Full Text Available ERPLAB Toolbox is a freely available, open-source toolbox for processing and analyzing event-related potential (ERP data in the MATLAB environment. ERPLAB is closely integrated with EEGLAB, a popular open-source toolbox that provides many EEG preprocessing steps and an excellent user interface design. ERPLAB adds to EEGLAB’s EEG processing functions, providing additional tools for filtering, artifact detection, re-referencing, and sorting of events, among others. ERPLAB also provides robust tools for averaging EEG segments together to create averaged ERPs, for creating difference waves and other recombinations of ERP waveforms through algebraic expressions, for filtering and re-referencing the averaged ERPs, for plotting ERP waveforms and scalp maps, and for quantifying several types of amplitudes and latencies. ERPLAB’s tools can be accessed either from an easy-to-learn graphical user interface or from MATLAB scripts, and a command history function makes it easy for users with no programming experience to write scripts. Consequently, ERPLAB provides both ease of use and virtually unlimited power and flexibility, making it appropriate for the analysis of both simple and complex ERP experiments. Several forms of documentation are available, including a detailed user’s guide, a step-by-step tutorial, a scripting guide, and a set of video-based demonstrations.

  19. Auditory event-related potentials and reaction time during decompression from hyperbaric trimix conditions.

    Science.gov (United States)

    Philipova, D

    1998-06-01

    Auditory event-related potentials (ERP) and sensomotor reaction time (RT) were investigated in divers during decompression from hyperbaric trimix conditions in order to assess the auditory information processing of the divers. Two passive series, 30 low (800 Hz) and 30 high (1200 Hz) tones were presented as well as one simple reaction task (SRT) and one choice reaction task (CRT) series. In both task series, the subjects were instructed to press the button as quickly as possible with the right-hand thumb after a low tone was heard. The individual analyses of the decompression period ERPs and RT data were compared with the pre-diving results for the series. Despite the interindividual differences, the sensomotor reactions were retarded during the decompression period, most clearly in the CRT. A prolongation of the N2 and P3 latency in this series gives grounds to accept that a cognitive slowing takes part in the longer reaction times during decompression. The slowing of the auditory information processing during decompression manifests with task manipulation difficulties.

  20. Rapid L2 Word Learning through High Constraint Sentence Context: An Event-Related Potential Study

    Directory of Open Access Journals (Sweden)

    Baoguo Chen

    2017-12-01

    Full Text Available Previous studies have found quantity of exposure, i.e., frequency of exposure (Horst et al., 1998; Webb, 2008; Pellicer-Sánchez and Schmitt, 2010, is important for second language (L2 contextual word learning. Besides this factor, context constraint and L2 proficiency level have also been found to affect contextual word learning (Pulido, 2003; Tekmen and Daloglu, 2006; Elgort et al., 2015; Ma et al., 2015. In the present study, we adopted the event-related potential (ERP technique and chose high constraint sentences as reading materials to further explore the effects of quantity of exposure and proficiency on L2 contextual word learning. Participants were Chinese learners of English with different English proficiency levels. For each novel word, there were four high constraint sentences with the critical word at the end of the sentence. Learners read sentences and made semantic relatedness judgment afterwards, with ERPs recorded. Results showed that in the high constraint condition where each pseudoword was embedded in four sentences with consistent meaning, N400 amplitude upon this pseudoword decreased significantly as learners read the first two sentences. High proficiency learners responded faster in the semantic relatedness judgment task. These results suggest that in high quality sentence contexts, L2 learners could rapidly acquire word meaning without multiple exposures, and L2 proficiency facilitated this learning process.

  1. EEG Channel Selection Using Particle Swarm Optimization for the Classification of Auditory Event-Related Potentials

    Directory of Open Access Journals (Sweden)

    Alejandro Gonzalez

    2014-01-01

    Full Text Available Brain-machine interfaces (BMI rely on the accurate classification of event-related potentials (ERPs and their performance greatly depends on the appropriate selection of classifier parameters and features from dense-array electroencephalography (EEG signals. Moreover, in order to achieve a portable and more compact BMI for practical applications, it is also desirable to use a system capable of accurate classification using information from as few EEG channels as possible. In the present work, we propose a method for classifying P300 ERPs using a combination of Fisher Discriminant Analysis (FDA and a multiobjective hybrid real-binary Particle Swarm Optimization (MHPSO algorithm. Specifically, the algorithm searches for the set of EEG channels and classifier parameters that simultaneously maximize the classification accuracy and minimize the number of used channels. The performance of the method is assessed through offline analyses on datasets of auditory ERPs from sound discrimination experiments. The proposed method achieved a higher classification accuracy than that achieved by traditional methods while also using fewer channels. It was also found that the number of channels used for classification can be significantly reduced without greatly compromising the classification accuracy.

  2. Sociality Mental Modes Modulate the Processing of Advice-Giving: An Event-Related Potentials Study

    Directory of Open Access Journals (Sweden)

    Jin Li

    2018-02-01

    Full Text Available People have different motivations to get along with others in different sociality mental modes (i.e., communal mode and market mode, which might affect social decision-making. The present study examined how these two types of sociality mental modes affect the processing of advice-giving using the event-related potentials (ERPs. After primed with the communal mode and market mode, participants were instructed to decide whether or not give an advice (profitable or damnous to a stranger without any feedback. The behavioral results showed that participants preferred to give the profitable advice to the stranger more slowly compared with the damnous advice, but this difference was only observed in the market mode condition. The ERP results indicated that participants demonstrated more negative N1 amplitude for the damnous advice compared with the profitable advice, and larger P300 was elicited in the market mode relative to both the communal mode and the control group. More importantly, participants in the market mode demonstrated larger P300 for the profitable advice than the damnous advice, whereas this difference was not observed at the communal mode and the control group. These findings are consistent with the dual-process system during decision-making and suggest that market mode may lead to deliberate calculation for costs and benefits when giving the profitable advice to others.

  3. Comparison of Auditory Event-Related Potential P300 in Sighted and Early Blind Individuals

    Directory of Open Access Journals (Sweden)

    Fatemeh Heidari

    2010-06-01

    Full Text Available Background and Aim: Following an early visual deprivation, the neural network involved in processing auditory spatial information undergoes a profound reorganization. In order to investigate this process, event-related potentials provide accurate information about time course neural activation as well as perception and cognitive processes. In this study, the latency and amplitude of auditory P300 were compared in sighted and early blind individuals in age range of 18-25 years old.Methods: In this cross-sectional study, auditory P300 potential was measured in conventional oddball paradigm by using two tone burst stimuli (1000 and 2000 Hz on 40 sighted subjects and 19 early blind subjects with mean age 20.94 years old.Results: The mean latency of P300 in early blind subjects was significantly smaller than sighted subjects (p=0.00.( There was no significant difference in amplitude between two groups (p>0.05.Conclusion: Reduced latency of P300 in early blind subjects in comparison to sighted subjects probably indicates the rate of automatic processing and information categorization is faster in early blind subjects because of sensory compensation. It seems that neural plasticity increases the rate of auditory processing and attention in early blind subjects.

  4. Neural Basis of Intrinsic Motivation: Evidence from Event-Related Potentials

    Directory of Open Access Journals (Sweden)

    Jia Jin

    2015-01-01

    Full Text Available Human intrinsic motivation is of great importance in human behavior. However, although researchers have focused on this topic for decades, its neural basis was still unclear. The current study employed event-related potentials to investigate the neural disparity between an interesting stop-watch (SW task and a boring watch-stop task (WS to understand the neural mechanisms of intrinsic motivation. Our data showed that, in the cue priming stage, the cue of the SW task elicited smaller N2 amplitude than that of the WS task. Furthermore, in the outcome feedback stage, the outcome of the SW task induced smaller FRN amplitude and larger P300 amplitude than that of the WS task. These results suggested that human intrinsic motivation did exist and that it can be detected at the neural level. Furthermore, intrinsic motivation could be quantitatively indexed by the amplitude of ERP components, such as N2, FRN, and P300, in the cue priming stage or feedback stage. Quantitative measurements would also be convenient for intrinsic motivation to be added as a candidate social factor in the construction of a machine learning model.

  5. Cortical processing of vowels and tones as measured by event-related desynchronization.

    Science.gov (United States)

    Krause, C M; Lang, H; Laine, M; Kuusisto, M; Pörn, B

    1995-01-01

    Event-Related Desynchronization (ERD) and Synchronization (ERS) were studied in 20 normal subjects during a Sternberg-type auditory memory-scanning paradigm. Half of the subjects performed the experiment with vowels and the other half with tones as stimuli. The stimuli consisted of 100 msec long synthesized vowels and 100 msec long tones produced by eight different synthesized instruments. In this paradigm each trial started with the presentation of a visual warning signal, after which a four-stimulus set was presented for memorization whether after a probe stimulus was presented and identified by the subject as belonging or not belonging to the memorized set. The ERD/ERS of the lower (8-10 Hz) and upper (10-12 Hz) alpha frequency bands differed in their reactivity to stimulus type; the differences between the two frequency bands reached statistical significance only in the case of vowels. The presentation of the memory set elicited ERS which was more pronounced in the 10-12 Hz frequency band and greater for vowels than for tones. On the other hand, the presentation of the probe elicited ERD which was greater for vowels than for tones, especially in the upper alpha frequency band. The results of this exploratory study suggest that ERD is closely related to memory process and that the ERD/ERS-technique might provide a valuable tool for future research encompassing more complex auditory stimulation like speech and music.

  6. Subliminal Emotional Words Impact Syntactic Processing: Evidence from Performance and Event-Related Brain Potentials

    Directory of Open Access Journals (Sweden)

    Laura Jiménez-Ortega

    2017-04-01

    Full Text Available Recent studies demonstrate that syntactic processing can be affected by emotional information and that subliminal emotional information can also affect cognitive processes. In this study, we explore whether unconscious emotional information may also impact syntactic processing. In an Event-Related brain Potential (ERP study, positive, neutral and negative subliminal adjectives were inserted within neutral sentences, just before the presentation of the supraliminal adjective. They could either be correct (50% or contain a morphosyntactic violation (number or gender disagreements. Larger error rates were observed for incorrect sentences than for correct ones, in contrast to most studies using supraliminal information. Strikingly, emotional adjectives affected the conscious syntactic processing of sentences containing morphosyntactic anomalies. The neutral condition elicited left anterior negativity (LAN followed by a P600 component. However, a lack of anterior negativity and an early P600 onset for the negative condition were found, probably as a result of the negative subliminal correct adjective capturing early syntactic resources. Positive masked adjectives in turn prompted an N400 component in response to morphosyntactic violations, probably reflecting the induction of a heuristic processing mode involving access to lexico-semantic information to solve agreement anomalies. Our results add to recent evidence on the impact of emotional information on syntactic processing, while showing that this can occur even when the reader is unaware of the emotional stimuli.

  7. Modafinil improves event related potentials P300 and contingent negative variation after 24 h sleep deprivation.

    Science.gov (United States)

    Ray, Koushik; Chatterjee, Abhirup; Panjwani, Usha; Kumar, Sanjeev; Sahu, Surajit; Ghosh, Sayan; Thakur, Lalan; Anand, Jag Parvesh

    2012-08-21

    The efficacy of modafinil as a countermeasure in the reduction of cognitive decline following 24 h of sleep deprivation (SD) on subjective sleepiness scales, event-related potential (ERP) P300, and contingent negative variation (CNV) was evaluated. Eleven healthy males, age 25-30 years participated. The experiment was performed in five sessions on different days between 7 and 8a.m. Session 1, baseline recordings; Session 2, after one night's SD; Session 3, 48 h of recovery from SD; Session 4, after 1 week of Session 1, following one night's SD along with modafinil (400mg/day); Session 5, 48 h of recovery after SD+modafinil. Subjective sleepiness scores increased significantly after SD as compared to baseline (PP300 peak latencies of ERP following SD (PP300 peak latencies after SD (PP300 amplitudes and CNV N100, M200 peak latencies and M100, M200 amplitudes were observed. The results strongly suggest that modafinil in a dose of 400mg/day, reduces the subjective sleepiness and cognitive decline following 24 h of SD. Copyright © 2012 Elsevier Inc. All rights reserved.

  8. "Cognitive" visual acuity estimation based on the event-related potential P300 component.

    Science.gov (United States)

    Heinrich, Sven P; Marhöfer, David; Bach, Michael

    2010-09-01

    An objective assessment of sensory and sensuo-cognitive function, based on physiological signals rather than on the behavioral response of a patient, is often advisable, albeit challenging. Evoked potentials are frequently used as an objective measure, but usually fail to detect defects beyond primary sensory areas, including those of psychogenic origin. Here we assess whether the event-related P300 component may be used to measure "cognitive" visual acuity. A visual oddball paradigm was used to elicit P300 responses in subjects with normal or artificially blurred vision. Probe stimuli consisted of infrequently presented gratings with spatial frequencies in the range of 2.2-16.2 cycles per degree, which could be either target or non-target stimuli depending on their orientation. Frequent stimuli were homogeneously grey fields. Without blur, rare stimuli of all spatial frequencies produced reliable P300 responses. Blur abolished the P300 to fine gratings consistently in 10 of 11 subjects. The drop in P300 amplitude was steep, rather than gradual, between visible and invisible gratings. The P300 is sensitive to identify the resolution threshold and thus may serve as a tool for estimating acuity in cases of visual impairments. The study presents a tool for the objective assessment of acuity in cases of higher-level visual impairments. The concept can most likely be extended to other sensory modalities. 2010 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  9. A feasibility study of using event-related potential as a biometrics.

    Science.gov (United States)

    Yih-Choung Yu; Sicheng Wang; Gabel, Lisa A

    2016-08-01

    The use of an individual's neural response to stimuli (the event-related potential or ERP) has potential as a biometric because it is highly resistant to fraud relative to other conventional authentication systems. P300 is an ERP in human electroencephalography (EEG) that occurs in response to an oddball stimulus when an individual is actively engaged in a target detection task. Because P300 is consistently detectable from almost every subject, it is considered a potential signal for biometric applications. This paper presents a feasibility study of using topological plots of P300 as a biometric in subject authentication. The variation in latency and location of P300 response of 24 participants performing the P300Speller task were studied. Data sets from four participants were used for algorithm training; data from the other 20 participants were used as imposters for algorithm validation. The result showed that the algorithm was able to correctly identify three out of these four participants. Validation test also proved that the algorithm was able to reject 95% of the imposters for those three authenticated participants.

  10. Magnetic stimulation at acupoints relieves mental fatigue: An Event Related Potential (P300) study.

    Science.gov (United States)

    Yang, Shuo; Qiao, Yanyun; Wang, Lei; Hao, Pengru

    2017-07-20

    Mental fatigue caused by continuous cognitive tasks represents one of the most worrying modern health problems. Event Related Potential (ERP) P300 is thought to be associated with cognitive function. This study aimed at characterizing the neural activity correlated with the attentional processes and exploring a novelty method which combine the magnetic stimulation and acupoint to relieve mental fatigue caused by continuous cognitive tasks. P300 (P3a and P3b) were extracted at three points: when subjects felt relaxed, at the point of mental fatigue, and after the subjects were stimulated at acupoints. The amplitudes and latencies of P3a and P3b were analyzed statistically. Among the four features (P3a amplitude, P3a latency, P3b amplitude, and P3b latency), only P3b amplitude was found to have a significant difference between the resting state and the mental fatigue state. And P3b amplitude significantly increased after magnetic stimulation at the acupoints. Subjects experiencing mental fatigue demonstrated a significant decrease in P3b amplitude in the parietal region, suggesting attenuation of resource allocation for selective attention. P3b amplitude significantly increased after magnetic stimulation at acupoints indicating that this strategy can be used to improve selective attention and relieve mental fatigue.

  11. A Discussion of Possibility of Reinforcement Learning Using Event-Related Potential in BCI

    Science.gov (United States)

    Yamagishi, Yuya; Tsubone, Tadashi; Wada, Yasuhiro

    Recently, Brain computer interface (BCI) which is a direct connecting pathway an external device such as a computer or a robot and a human brain have gotten a lot of attention. Since BCI can control the machines as robots by using the brain activity without using the voluntary muscle, the BCI may become a useful communication tool for handicapped persons, for instance, amyotrophic lateral sclerosis patients. However, in order to realize the BCI system which can perform precise tasks on various environments, it is necessary to design the control rules to adapt to the dynamic environments. Reinforcement learning is one approach of the design of the control rule. If this reinforcement leaning can be performed by the brain activity, it leads to the attainment of BCI that has general versatility. In this research, we paid attention to P300 of event-related potential as an alternative signal of the reward of reinforcement learning. We discriminated between the success and the failure trials from P300 of the EEG of the single trial by using the proposed discrimination algorithm based on Support vector machine. The possibility of reinforcement learning was examined from the viewpoint of the number of discriminated trials. It was shown that there was a possibility to be able to learn in most subjects.

  12. Working memory deficit in patients with restless legs syndrome: an event-related potential study.

    Science.gov (United States)

    Kim, Sung Min; Choi, Jeong Woo; Lee, Chany; Lee, Byeong Uk; Koo, Yong Seo; Kim, Kyung Hwan; Jung, Ki-Young

    2014-07-01

    The aim of this study was to investigate whether there is a working memory (WM) deficit in restless legs syndrome (RLS) patients, by studying the Sternberg WM task of event-related potential (ERP). Thirteen drug-naive RLS patients and 13 healthy age-matched controls with no sleep disturbances participated in the present study. P300 ERP was recorded during Sternberg WM task using digits as mnemonic items. P300 amplitudes and reaction times were compared between groups (RLS vs. control) considering brain regions (frontal, central, and parietal) and memory load sizes (two, three, and four) as within-subject factors. Clinical and sleep-related variables were correlated with P300 amplitude. The reaction time in RLS patients was significantly longer than controls over all memory load sizes. The P300 amplitude at parietal regions in RLS patients was significantly lower than in controls regardless of memory load sizes, which was significantly negatively correlated with duration of RLS history in RLS patients. Our study suggests that patients with severe RLS have WM deficits. Furthermore, negative correlation of P300 amplitudes with the duration of RLS illness suggests that cerebral cortical dysfunction in RLS patients results from repeated RLS symptom attacks. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. The Event-related Potential P300 in Patients with Migraine.

    Science.gov (United States)

    Titlic, Marina; Mise, Nikolina Ivica; Pintaric, Irena; Rogosic, Veljko; Vanjaka-Rogosic, Lucija; Mihalj, Mario; Jurinovic, Pavao; Katic, Ana Curkovic; Andjelinovic, Maja

    2015-12-01

    Recording of event-related potentials by using oddball paradigm of auditory P300 has yielded conflicting results in migraine. The aim of this study was to demonstrate that migraine patients have reduced P300 amplitude and prolonged P300 latency, suggesting alterations of the cognitive-evaluative component. We recruited 29 migraine patients (24 females; median age 40 years) and 29 healthy age- and gender-matched participants. Participants were subjected to the same testing procedures of auditory P300 by discrimination the target auditory stimulus from the frequent stimulus, and analyzing P300 target/frequent stimulus amplitudes, and P300 target/frequent stimulus latencies. Patients with migraine don't have prolonged P300 target stimulus latency, but have a longer P300 frequent stimulus latency for 17.5ms. Out of 29 participants with migraine 8 had pathological P300 target stimulus amplitude, and 19 had pathological P300 frequent stimulus amplitude. People with migraine have altered the P300 which indicates the presence of cognitive dysfunction in these patients and importance of early diagnosis and intervention to preventing any deterioration in cognitive functions.

  14. Dopaminergic mechanisms of target detection - P300 event related potential and striatal dopamine.

    Science.gov (United States)

    Pogarell, Oliver; Padberg, Frank; Karch, Susanne; Segmiller, Felix; Juckel, Georg; Mulert, Christoph; Hegerl, Ulrich; Tatsch, Klaus; Koch, Walter

    2011-12-30

    The P300 is a cortically generated event related potential (ERP) widely used in neurophysiological research since it is related to cognitive functions and central information processing. Intracerebral recordings and functional neuroimaging studies have demonstrated that this potential is generated by various brain regions including frontal, temporal and parietal cortices. Regarding the neurochemical background, clinical and genetic investigations suggest that dopaminergic neurons could be involved in the generation of the P300. However, there is no direct evidence in vivo that P300 amplitudes and latencies are related to dopaminergic parameters. The aim of this study was to further elucidate dopaminergic aspects of the P300 ERP by combining neurophysiological and nuclear medicine assessments in vivo. Patients with a major depressive episode underwent both P300 recordings and dynamic [¹²³I] IBZM SPECT for the evaluation of striatal dopamine D₂/D₃-receptor availability. There were statistically significant positive correlations of the striatal dopamine D₂/D₃-receptor status with P300 amplitudes and significant negative correlations with P300 latencies. Using this combined approach, the study presents direct evidence in vivo that the central dopaminergic system might play an important role in the generation of the P300 and that central dopaminergic activity could be involved in the modulation of P300 parameters. This association might be of relevance for the interpretation of P300 studies in psychiatric disorders. 2011 Elsevier Ireland Ltd. All rights reserved.

  15. P300 event related potential application to cognitive status assessment of the patients with subclinical hypothyroidism

    Directory of Open Access Journals (Sweden)

    Dejanović M.

    2015-01-01

    Full Text Available Disturbances of thyroid function are often accompanied by cognitive and affective disorders. Assessment of cognitive status in the patients with subclinical hypothyroidism represents a possibility for early diagnostics of cognitive impairment and timely introduction of necessary pharmacotherapy treatment. The aim of this study was to quantify whether there are P3 event related potential (ERP deviations as electrophysiological markers of cognitive activity in patients with subclinical hypothyroidism. P300 potentials were examined in thirty patients with subclinical hypothyroidism and in 30 healthy subjects of the control group. P300 was recorded using the classic auditory oddball paradigm, with 20% of target and 80% of non-target stimuli. The results analysis showed a significantly longer latency P300 and reduced amplitude P300 in subjects with subclinical hypothyroidism compared to euthyroid subjects. There is also a statistically significant negative correlation between the results of a mini mental state examination and the P300 latency at Fz electrode (r= -0.47, p <0.01 and Cz electrode (r= -0.43, p =0.017. P300 ERP is important in the evaluation of patients with subclinical hypothyroidism, due to the sensitivity in the detection cognitive disorders.

  16. Latency correction of event-related potentials between different experimental protocols

    Science.gov (United States)

    Iturrate, I.; Chavarriaga, R.; Montesano, L.; Minguez, J.; Millán, JdR

    2014-06-01

    Objective. A fundamental issue in EEG event-related potentials (ERPs) studies is the amount of data required to have an accurate ERP model. This also impacts the time required to train a classifier for a brain-computer interface (BCI). This issue is mainly due to the poor signal-to-noise ratio and the large fluctuations of the EEG caused by several sources of variability. One of these sources is directly related to the experimental protocol or application designed, and may affect the amplitude or latency of ERPs. This usually prevents BCI classifiers from generalizing among different experimental protocols. In this paper, we analyze the effect of the amplitude and the latency variations among different experimental protocols based on the same type of ERP. Approach. We present a method to analyze and compensate for the latency variations in BCI applications. The algorithm has been tested on two widely used ERPs (P300 and observation error potentials), in three experimental protocols in each case. We report the ERP analysis and single-trial classification. Main results. The results obtained show that the designed experimental protocols significantly affect the latency of the recorded potentials but not the amplitudes. Significance. These results show how the use of latency-corrected data can be used to generalize the BCIs, reducing the calibration time when facing a new experimental protocol.

  17. Reduced NGF serum levels and abnormal P300 event-related potential in first episode schizophrenia.

    Science.gov (United States)

    Xiong, Peng; Zeng, Yong; Zhu, Zuxin; Tan, Deyong; Xu, Fei; Lu, Jin; Wan, Jing; Ma, Mingxing

    2010-06-01

    Nerve growth factor (NGF) plays a crucial role in central nervous system neuron plasticity. Low levels of serum NGF in schizophrenic patients suggest that the neurotrophin contributes to the pathogenesis of the disease. NGF is also thought to alter characteristics of event-related brain potential (ERP) components. The auditory-evoked P300 ERP component, considered an index of brain activity, has reduced amplitude in acute and chronic schizophrenia. This study evaluated the relationship among serum NGF levels, P300 characteristics, and Positive and Negative Symptom Scale (PANSS) scores in first episode, neuroleptic naive schizophrenic patients (N=30) and healthy controls (N=28). Serum NGF was measured by ELISA and P300 elicited using auditory oddball paradigm. Compared to control subjects, schizophrenic patients had significantly reduced serum NGF (pP300 amplitudes at Fz (p=0.003). Additionally, there was a positive correlation between serum NGF serum and P300 amplitude at Fz. No correlation was found between serum NGF or P300 characteristics and PANSS scores. These results suggest that the effects of NGF in schizophrenia are related not only to regulation of neurodevelopment, but also to the electrophysiological characteristics of nerve growth factor. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  18. The event-related brain potential as an index of attention allocation in complex displays

    Science.gov (United States)

    Wickens, C. D.; Heffley, E. F.; Kramer, A. F.; Donchin, E.

    1980-01-01

    The advantages of employing the event-related brain potential (ERP) in the assessment of allocation of attention in dynamic environments are discussed. Three experiments are presented in which the P300 component of the ERP is demonstrated to be a useful index of subjects' locus of attention. The first two experiments were concerned with the allocation of attention during discrete and continuous visual monitoring tasks. The results indicated that a P300 was elicited only by stimuli to which the subject had to attend in order to perform successfully the task. The third experiment was conducted to assess the sensitivity of P300 to the manner in which attention is allocated to different aspects of a display during the performance of a 3-dimensional target acquisition task. The amplitude of the P300 was found to reflect differences between two levels of workload, as well as the task relevance of the stimuli. The results of the experiments are discussed in terms of their utility in the evaluation of the design of man-machine systems as well as in the study of the allocation of attention in operational environments.

  19. Importance Modulates the Temporal Features of Self-Referential Processing: An Event-Related Potential Study.

    Science.gov (United States)

    Xu, Kepeng; Li, Shifeng; Ren, Deyun; Xia, Ruixue; Xue, Hong; Zhou, Aibao; Xu, Yan

    2017-01-01

    A growing number of studies have demonstrated preferential processing of self-related information. However, previous research has been limited in examining the distinction between processes related to the self and those related to the non-self, it remains unclear how self-related information with differing levels of importance is processed within the self. The present study examined how the importance of self-related content affects the neural activity involved in self-referential processing. The behavioral results showed that the participants had faster responses to more important self-related content. The event-related potential (ERP) results showed that early attention resources were diverted to the identification of highly important self-related content compared with minimally important self-related content, as reflected by the enhanced P200. Furthermore, the N200 amplitude for highly important self-related content was smaller than for moderately important self-related content which, in turn, were smaller than minimally important self-related content. Moreover, the P300 amplitudes were modulated by the degree of importance of self-related content, whereby a higher importance of self-related content led to larger P300 amplitudes. Taken together, these findings demonstrate an effect of the degree of importance of the self-related content at both behavioral and neurophysiological levels.

  20. Importance Modulates the Temporal Features of Self-Referential Processing: An Event-Related Potential Study

    Directory of Open Access Journals (Sweden)

    Kepeng Xu

    2017-09-01

    Full Text Available A growing number of studies have demonstrated preferential processing of self-related information. However, previous research has been limited in examining the distinction between processes related to the self and those related to the non-self, it remains unclear how self-related information with differing levels of importance is processed within the self. The present study examined how the importance of self-related content affects the neural activity involved in self-referential processing. The behavioral results showed that the participants had faster responses to more important self-related content. The event-related potential (ERP results showed that early attention resources were diverted to the identification of highly important self-related content compared with minimally important self-related content, as reflected by the enhanced P200. Furthermore, the N200 amplitude for highly important self-related content was smaller than for moderately important self-related content which, in turn, were smaller than minimally important self-related content. Moreover, the P300 amplitudes were modulated by the degree of importance of self-related content, whereby a higher importance of self-related content led to larger P300 amplitudes. Taken together, these findings demonstrate an effect of the degree of importance of the self-related content at both behavioral and neurophysiological levels.

  1. Event related potential (ERP) P300 after 6 months residence at 4115 meter.

    Science.gov (United States)

    Thakur, Lalan; Ray, Koushik; Anand, J P; Panjwani, Usha

    2011-07-01

    The P300 wave is an event related potential (ERP) elicited by infrequent, task-relevant stimuli and appeared at about 300 ms, represents higher cognitive function of information processing, working memory or stimulus categorization. Hypobaric hypoxia deteriorates the cognitive function during the short term stay (days to few weeks) at high altitude. The present study was carried out to evaluate the P300 responses during long duration stay (1 month and 6 months) at high altitude (HA, 4115 m) in a sample of Indian lowlanders. The study was carried out on 18 healthy male volunteers at sea level (SL). The volunteers were stage inducted to 4115 m altitude in the Eastern Himalayas. The P300 was recorded after 1 and 6 months of their stay at HA. The latencies of peaks N100, P200 and N200 waves did not show any significant changes after 1 and 6 months of stay at HA as compared to SL. The P300 latency was significantly delayed after 1 month and further delayed after 6 month of residence at 4115 m. The P200 and P300 amplitudes did not show any changes. The increase in P300 latency indicated that long duration of stay at high altitude slows the stimulus evaluation processes. The observations suggest that hypoxia causes slowing of the signal processing at HA. The magnitude of the effects of hypobaric hypoxia may be dependent upon the duration of residence at high altitude.

  2. Tyrosine ameliorates heat induced delay in event related potential P300 and contingent negative variation.

    Science.gov (United States)

    Kishore, Krishna; Ray, Koushik; Anand, J P; Thakur, Lalan; Kumar, Sanjeev; Panjwani, Usha

    2013-12-01

    The efficacy of tyrosine, a catecholamine precursor, as a countermeasure in the reduction of cognitive decline during heat exposure (HE) using event-related potential P300, and contingent negative variation (CNV) was evaluated. Ten healthy males, age 20-30years participated in the study. Volunteers received placebo or tyrosine (6.5g) 90min prior to HE (1.5h in 45°C+30% RH). P300 latency was significantly increased (p<0.01) during exposure with placebo, which was reduced significantly (p<0.01) after tyrosine supplementation. There was an increase in CNV M100 latency (p<0.05) and reaction time (p<0.01) and decrease in M100 amplitude (p<0.01) during HE with placebo, which returns to near normal level with the tyrosine administration. A significantly higher plasma norepinephrine (p<0.05), dopamine and epinephrine levels were detected in tyrosine supplemented group post heat exposure. HE increases the brain catecholamine activity thereby reduces the plasma norepinephrine and dopamine level leading to a reduction in cognitive performances. Tyrosine supplementation increases the catecholamine level and reduces the impairment of cognitive performance during HE. Copyright © 2013 Elsevier Inc. All rights reserved.

  3. [Changes of the event related potential P300 following topiramate treatment in children with epilepsy].

    Science.gov (United States)

    Yang, Wen; Li, Mei

    2008-10-01

    The event related potential (ERP-P300) is useful to determine cognitive disturbances. This study examined the changes of ERP-P300 following different dosages of topiramate (TPM) treatment in children with epilepsy in order to investigate the effect of different dosages of TPM on cognitive function. Thirty cases of benign childhood epilepsy with centrotemporal spikes (BECTS) were first administered with TPM at a dosage of 2 mg/kg/d for 6 months. Afterwards they received another 6 months of TPM treatment at a dosage of 5 mg/kg/d. ERP-P300 was tested before and after different dosages of TPM treatment. There were no significant differences in the latency and amplitude of ERP-P300 before and after 6 months low dosages of TPM treatment. However, the latency was more prolonged and the amplitude was reduced in the ERP-P300 testing after 6 months high dosage of TMP treatment (Prelated to its dosage in children with epilepsy.

  4. Relationship between early and late stages of information processing: an event-related potential study

    Directory of Open Access Journals (Sweden)

    Claudio Portella

    2012-11-01

    Full Text Available The brain is capable of elaborating and executing different stages of information processing. However, exactly how these stages are processed in the brain remains largely unknown. This study aimed to analyze the possible correlation between early and late stages of information processing by assessing the latency to, and amplitude of, early and late event-related potential (ERP components, including P200, N200, premotor potential (PMP and P300, in healthy participants in the context of a visual oddball paradigm. We found a moderate positive correlation among the latency of P200 (electrode O2, N200 (electrode O2, PMP (electrode C3, P300 (electrode PZ and the reaction time (RT. In addition, moderate negative correlation between the amplitude of P200 and the latencies of N200 (electrode O2, PMP (electrode C3, P300 (electrode PZ was found. Therefore, we propose that if the secondary processing of visual input (P200 latency occurs faster, the following will also happen sooner: discrimination and classification process of this input (N200 latency, motor response processing (PMP latency, reorganization of attention and working memory update (P300 latency, and RT. N200, PMP, and P300 latencies are also anticipated when higher activation level of occipital areas involved in the secondary processing of visual input rise (P200 amplitude.

  5. Individuals' attentional bias toward an envied target's name: an event-related potential study.

    Science.gov (United States)

    Zhong, Jun; Liu, Yongfang; Zhang, Entao; Luo, Junlong; Chen, Jie

    2013-08-29

    Individuals may pay more attention to information about envied targets. Thus, we further investigate the neural correlates underlying the cognitive processing of envy-related stimuli. Participants read information about target persons characterized by two domains: levels of possession and self-relevance of comparison. Event-related potentials (ERPs) were then recorded for three target names (high-envy, moderate-envy, and low-envy) while participants performed a three-stimulus oddball task. The results showed that high- and moderate-envy target names elicited larger P300 amplitudes than did low-envy target names. Specifically, high-envy target names elicited larger P300 amplitudes than did low-envy target names at the left, central, and right sites; in contrast, moderate-envy target names elicited larger P300 amplitudes than did low-envy target names only at central sites. P300 amplitudes did not differ between high- and moderate-envy target names. Thus, we extend previous behavioral findings by showing that people preferentially attend toward envy-related stimuli, as reflected by enhanced P300 amplitudes. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  6. Subclinical alexithymia modulates early audio-visual perceptive and attentional event-related potentials

    Directory of Open Access Journals (Sweden)

    Dyna eDelle-Vigne

    2014-03-01

    Full Text Available Introduction:Previous studies have highlighted the advantage of audio–visual oddball tasks (instead of unimodal ones in order to electrophysiologically index subclinical behavioral differences. Since alexithymia is highly prevalent in the general population, we investigated whether the use of various bimodal tasks could elicit emotional effects in low- versus high-alexithymic scorers. Methods:Fifty students (33 females were split into groups based on low and high scores on the Toronto Alexithymia Scale. During event-related potential recordings, they were exposed to three kinds of audio–visual oddball tasks: neutral (geometrical forms and bips, animal (dog and cock with their respective shouts, or emotional (faces and voices stimuli. In each condition, participants were asked to quickly detect deviant events occurring amongst a train of frequent matching stimuli (e.g., push a button when a sad face–voice pair appeared amongst a train of neutral face–voice pairs. P100, N100, and P300 components were analyzed: P100 refers to visual perceptive processing, N100 to auditory ones, and the P300 relates to response-related stages. Results:High-alexithymic scorers presented a particular pattern of results when processing the emotional stimulations, reflected in early ERP components by increased P100 and N100 amplitudes in the emotional oddball tasks (P100: pConclusions:Our findings suggest that high-alexithymic scorers require heightened early attentional resources when confronted with emotional stimuli.

  7. Identifying the null subject: evidence from event-related brain potentials.

    Science.gov (United States)

    Demestre, J; Meltzer, S; García-Albea, J E; Vigil, A

    1999-05-01

    Event-related brain potentials (ERPs) were recorded during spoken language comprehension to study the on-line effects of gender agreement violations in controlled infinitival complements. Spanish sentences were constructed in which the complement clause contained a predicate adjective marked for syntactic gender. By manipulating the gender of the antecedent (i.e., the controller) of the implicit subject while holding constant the gender of the adjective, pairs of grammatical and ungrammatical sentences were created. The detection of such a gender agreement violation would indicate that the parser had established the coreference relation between the null subject and its antecedent. The results showed a complex biphasic ERP (i.e., an early negativity with prominence at anterior and central sites, followed by a centroparietal positivity) in the violating condition as compared to the non-violating conditions. The brain reacts to NP-adjective gender agreement violations within a few hundred milliseconds of their occurrence. The data imply that the parser has properly coindexed the null subject of an infinitive clause with its antecedent.

  8. Slowing of Event-Related Potentials in Primary Progressive Aphasia. A case report

    Directory of Open Access Journals (Sweden)

    Salvatore Giaquinto

    2009-01-01

    Full Text Available Primary Progressive Aphasia (PPA is a rare and insidious language impairment that worsens over time. It belongs to the group of fronto–temporal dementias. This study was aimed at assessing the role of speed of cognitive abilities, such as word recognition, in PPA. The design is a single-case, longitudinal study. A male patient suffering from PPA was enrolled and 15 healthy older adults were the control group. An event-related electrical potential connected with word recognition, namely the N400, was delayed by 200 msec at baseline compared to healthy controls and progressively deteriorated. One year later, the delay was greater and two years later the potential had disappeared. Reduced speed of processing is an early pathological factor that negatively affecting higher cognitive functions in APP. Event–related electrical potentials are recommended in the field of aphasia and cognitive decline. They permit observation of a speed decline in higher cognitive abilities, when pathological changes at a central level begin and language comprehension seems to be unaffected.

  9. Single-Trial Event-Related Potential Based Rapid Image Triage System

    Directory of Open Access Journals (Sweden)

    Ke Yu

    2011-06-01

    Full Text Available Searching for points of interest (POI in large-volume imagery is a challenging problem with few good solutions. In this work, a neural engineering approach called rapid image triage (RIT which could offer about a ten-fold speed up in POI searching is developed. It is essentially a cortically-coupled computer vision technique, whereby the user is presented bursts of images at a speed of 6–15 images per second and then neural signals called event-related potential (ERP is used as the ‘cue’ for user seeing images of high relevance likelihood. Compared to past efforts, the implemented system has several unique features: (1 it applies overlapping frames in image chip preparation, to ensure rapid image triage performance; (2 a novel common spatial-temporal pattern (CSTP algorithm that makes use of both spatial and temporal patterns of ERP topography is proposed for high-accuracy single-trial ERP detection; (3 a weighted version of probabilistic support-vector-machine (SVM is used to address the inherent unbalanced nature of single-trial ERP detection for RIT. High accuracy, fast learning, and real-time capability of the developed system shown on 20 subjects demonstrate the feasibility of a brainmachine integrated rapid image triage system for fast detection of POI from large-volume imagery.

  10. Marcelian charm in nursing practice: the unity of agape and eros as the foundation of an ethic of care.

    Science.gov (United States)

    Pembroke, Neil

    2006-10-01

    In the nursing literature, a number of qualities are associated with loving care. Reference is made to, among other things, humility, attentiveness, responsibility and duty, compassion, and tenderness. The author attempts to show that charm, in the Marcelian sense, also plays a central role. It is argued that the moral foundation of charm is a unity of agape and eros. An impartial giving of the self for others is clearly of fundamental importance in an ethic of care. Including charm in the discussion points to the fact that eros also plays a crucial role. Eros produces a passion for people and for life. It is a physical and spiritual energy that animates a person in all facets of her life, including her caring work.

  11. Relationship between somatosensory event-related potential N140 aberrations and hemispatial agnosia in patients with stroke: a preliminary study.

    Science.gov (United States)

    Ueno, Tomoyuki; Hada, Yasushi; Shimizu, Yukiyo; Yamada, Thoru

    2017-10-27

    The somatosensory event-related potential N140 is thought to be related to selective attention. This study aimed to compare the somatosensory event-related potential N140 in healthy subjects to that in patients with stroke to determine whether N140 and attentiveness are associated in patients with stroke with or without hemispatial agnosia. Normal somatosensory event-related potential N140 values were determined using data from ten healthy subjects. Fifteen patients with stroke were divided into two groups based on the presence of hemispatial neglect. Somatosensory event-related potential N140 components were compared between the two groups. Stimulation of the affected limb in the hemispatial agnosia group resulted in significantly longer N140 latency at the contralateral vs. the ipsilateral electrode. This was the inverse of the relationship observed in normal subjects, with stimulation of the intact side in patients with hemispatial agnosia, and with stimulation of both the intact and affected sides in patients without agnosia. In the hemispatial agnosia group, the peak latency of N140 following stimulation of the affected side was significantly longer than it was following stimulation of the intact side and when compared to that in patients without agnosia. In addition, abnormal N140 peak latencies were observed at the Cz and ipsilateral electrodes in patients with hemispatial agnosia following stimulation of the intact side. These findings suggest that somatosensory event-related potential N140 is independently generated in each hemisphere and may reflect cognitive attention.

  12. Intentions to quit smoking: causal attribution, perceived illness severity, and event-related fear during an acute health event.

    Science.gov (United States)

    Boudreaux, Edwin D; Moon, Simon; Baumann, Brigitte M; Camargo, Carlos A; O'Hea, Erin; Ziedonis, Douglas M

    2010-12-01

    Experiencing a serious consequence related to one's health behavior may motivate behavior change. This study sought to examine how causal attribution, perceived illness severity, and fear secondary to an acute health event relate to intentions to quit smoking. Using a cross-sectional survey design, adult emergency department patients who smoked provided demographic data and ratings of nicotine dependence, causal attribution, perceived illness severity, event-related fear, and intentions to quit smoking. A linear regression analysis was used to examine the relations between the independent variables and quit intentions. We enrolled 186 participants. After adjusting for nicotine dependence, smoking-related causal attribution and event-related fear were associated with intentions to quit (β = 0.26, p < 0.01 and β = 0.21, p < 0.01, respectively). Perceived illness severity was correlated with event-related fear (r = 0.46, p < 0.001) but was not associated with intentions to quit (β = -0.08, p = 0.32). While causal attribution and event-related fear were modestly associated with quit intentions, perceived illness severity was not. Longitudinal studies are needed to better explicate the relation between these variables and behavior change milestones.

  13. Remotely sensed data available from the US Geological Survey EROS Data Center

    Science.gov (United States)

    Dwyer, J.L.; Qu, J.J.; Gao, W.; Kafatos, M.; Murphy , R.E.; Salomonson, V.V.

    2006-01-01

    The Center for Earth Resources Observation Systems (EROS) is a field center of the geography discipline within the US geological survey (USGS) of the Department of the Interior. The EROS Data Center (EDC) was established in the early 1970s as the nation’s principal archive of remotely sensed data. Initially the EDC was responsible for the archive, reproduction, and distribution of black-and-white and color-infrared aerial photography acquired under numerous mapping programs conducted by various Federal agencies including the USGS, Department of Agriculture, Environmental Protection Agency, and NASA. The EDC was also designated the central archive for data acquired by the first satellite sensor designed for broad-scale earth observations in support of civilian agency needs for earth resource information. A four-band multispectral scanner (MSS) and a return-beam vidicon (RBV) camera were initially flown on the Earth Resources Technology Satellite-1, subsequently designated Landsat-1. The synoptic coverage, moderate spatial resolution, and multi-spectral view provided by these data stimulated scientists with an unprecedented perspective from which to study the Earth’s surface and to understand the relationships between human activity and natural systems.

  14. Can EROS/MACHO be detecting the galactic spheroid instead of the galactic halo?

    CERN Document Server

    Giudice, Gian Francesco; Roulet, Esteban

    1994-01-01

    Models of our galaxy based on dynamical observations predict a spheroid component much heavier than accounted for by direct measurements of star counts and high velocity stars. If, as first suggested by Caldwell and Ostriker, this discrepancy is due to a large population of faint low-mass stars or dark objects in the spheroid, the spheroid could be responsible for microlensing events for sources in the LMC. We show that, although the rate of events is lower than predicted by a galactic halo made of microlensing objects, it is still significant for EROS/MACHO observations. Because of the different matter distributions in the halo and spheroid components, a comparison between microlensing event rates in the LMC, future measurements of microlensing in the galactic bulge and, possibly, in M31 can provide information about the amounts of dark objects in the different galactic components. If the EROS/MACHO collaborations find a deficiency with respect to their halo expectation, when more statistics are available, t...

  15. Seismic resurfacing by a single impact on the asteroid 433 Eros.

    Science.gov (United States)

    Thomas, P C; Robinson, Mark S

    2005-07-21

    Impact cratering creates a wide range of topography on small satellites and asteroids. The population of visible craters evolves with impacts, and because there are no competing endogenic processes to modify the surface, determining the various ways younger craters add to or subtract from the population is a fundamental aspect of small-body geology. Asteroid 433 Eros, the most closely studied small body, has regions of substantially different crater densities that remain unexplained. Here we show that the formation of a relatively young crater (7.6 km in diameter) resulted in the removal of other craters as large as 0.5 km over nearly 40 percent of the asteroid. Burial by ejecta cannot explain the observed pattern of crater removal. The limitation of reduced crater density to a zone within a particular straight-line distance through the asteroid from the centre of the large crater suggests degradation of the topography by seismic energy released during the impact. Our observations indicate that the interior of Eros is sufficiently cohesive to transmit seismic energy over many kilometres, and the outer several tens of metres of the asteroid must be composed of relatively non-cohesive material.

  16. Una nueva Figlina de la Hispania citerior : la oficina de L. Eros

    Directory of Open Access Journals (Sweden)

    Antonio M. Poveda Navarro

    1998-01-01

    Full Text Available Evaluamos el significado cultural y económico de la presencia de un nuevo alfar romano, tardo-republicano, dedicado a la fabricación de material de construcción, lucernas y al menos cerámica común romana, que fue implantado en territorio indígena, ibérico contestano, en pleno proceso de su romanización. Además, se relaciona a su propietario, L. Eros, con ciertos productos cerámicos hallados en Ampurias y alguno de los que teniendo allí su origen fian aparecido en su fiorno de El Monastil (EIda, Alicante.We are evaluating the cultural and economical importance of the presence of a new late-republican Román pottery place which is devoted to the manufacturing of building materials, pottery-lamps and common román pottery which was implanted in indigenous territory, Contestan-iberian, in the process of Romanization, besides, the owner, L. Eros, is related to certain pottery producís found in Ampurias and some of which having its origins there have been found in his oven of El Monastil (EIda, Alicante.

  17. Eros e paz nas comédias de Aristófanes

    Directory of Open Access Journals (Sweden)

    Ana Maria César Pompeu

    2016-07-01

    Full Text Available Aristophanes links Eros to peace in his comedies. In Acharnians, 425 BC, Dikaeopolis, an Athenian citizen, obtains private truce with the Spartans for himself and his family. He does not share his peace with anyone else, except with a bride, because she is  a woman and not is blamed for the war. It will have part of the fiance in their wedding. In Peace, 421 BC, Trigeu a grape-gatherer solves fly in a scarab beetle, who eats feces, to speak to the gods for peace, and ends up rescuing the Eirene goddess (Peace, contained in a cave by Polemos (War. Peace brings the goddess Opora (Autumnal or Harvest, with whom the protagonist marries, and the goddess Theoria (Feast, which is given to prytanes in the theater itself. In Lysistrata, in 411 BC, the women of Greece under the leadership of the Athenian Lysistrata make a sex strike to force their husbands to end up the war. The Myrrhine character and her husband, Kinesias, demonstrate how is the seduction and the refusal of women compared to men. We propose to link Eros to peace in the three pieces presented and Thesmoforiazusai (Demeterkoreazusai, the same year of Lysistrata and very close to it in some important ways, such as bringing a female choir, performing the separation of couples, making the apology of women and promote peace, because it is a religious festival of fertility, the Thesmophoria, parties in honor of the goddesses Demeter and Kore.

  18. SOME ASPECTS OF SATELLITE IMAGERY INTEGRATION FROM EROS B AND LANDSAT 8

    Directory of Open Access Journals (Sweden)

    A. Fryskowska

    2016-06-01

    Full Text Available The Landsat 8 satellite which was launched in 2013 is a next generation of the Landsat remote sensing satellites series. It is equipped with two new sensors: the Operational Land Imager (OLI and the Thermal Infrared Sensor (TIRS. What distinguishes this satellite from the previous is four new bands (coastal aerosol, cirrus and two thermal infrared TIRS bands. Similar to its antecedent, Landsat 8 records electromagnetic radiation in a panchromatic band at a range of 0.5‐0.9 μm with a spatial resolution equal to 15 m. In the paper, multispectral imagery integration capabilities of Landsat 8 with data from the new high resolution panchromatic EROS B satellite are analyzed. The range of panchromatic band for EROS B is 0.4‐0.9 μm and spatial resolution is 0.7 m. Research relied on improving the spatial resolution of natural color band combinations (bands: 4,3,2 and of desired false color band composition of Landsat 8 satellite imagery. For this purpose, six algorithms have been tested: Brovey’s, Mulitplicative, PCA, IHS, Ehler's, HPF. On the basis of the visual assessment, it was concluded that the best results of multispectral and panchromatic image integration, regardless land cover, are obtained for the multiplicative method. These conclusions were confirmed by statistical analysis using correlation coefficient, ERGAS and R-RMSE indicators.

  19. Low-cost surveys of the Domus of Stallius Eros in Pompeii

    Science.gov (United States)

    Bosco, A.; Barbarino, M.; Valentini, R.; D'Andrea, A.

    2015-02-01

    In the framework of the Project 3D-ICONS (www.3dicons-project.eu), different large archaeological models were acquired in Pompeii. In particular, the 3D Model of the House of Stallius Eros (Regio I, Insula VI, 13 - 14) was realized. This house conserves a rich vertical stratigraphy covering a large chronological period and offers interesting information about the development of this side of the ancient city. To implement a detailed survey of the house and to reconstruct the original structure of the domus, different types of survey were carried out, in order to provide a complete 3D model of the house. Three data-acquisition methodologies were used and their final results were compared in order to measure their accuracy, efficacy and velocity. At first, the domus was surveyed by an electronical total station, then two different interventions with un-calibrated photogrammetry were planned. The paper presents some preliminary results obtained by the three methodologies and the integration of the three models. The computational environments reproducing the ancient Domus of Stallius Eros allows to propose new archaeological interpretations and hypothesis about the reconstruction of the ancient House.

  20. ERO modeling of Cr sputtering in the linear plasma device PSI-2

    Science.gov (United States)

    Eksaeva, A.; Borodin, D.; Kreter, A.; Nishijima, D.; Pospieszczyk, A.; Schlummer, T.; Ertmer, S.; Terra, A.; Unterberg, B.; Kirschner, A.; Romazanov, J.; Brezinsek, S.; Rasinski, M.; Henderson, S.; O’Mullane, M.; Summers, H.; Bluteau, M.; Marenkov, E.

    2017-12-01

    The prediction of the first wall deterioration and possible plasma contamination by impurities is a high priority task for ITER. 3D Monte-Carlo code ERO is a tool for modeling of eroded impurity transport and spectroscopy in plasma devices useful for experiment interpretation. Chromium (Cr) is a fusion-relevant reactor wall element (e.g. component of RAFM steels expected for use in DEMO). Linear plasma devices including PSI-2 are effective tools for investigations of plasma-surface interaction effects, allowing continuous plasma operation and good control over irradiation parameters. Experiments on Cr sputtering were conducted at PSI-2. In these experiments the Cr erosion was measured by three techniques: mass loss of the sample, quartz micro-balance of deposited impurities at a distance from it and optical emission spectroscopy. Experiments were modeled with the 3D Monte-Carlo code ERO, previously validated by application to similar experiments with tungsten (W). The simulations are demonstrated to reproduce the main experimental outcomes proving the quality of the sputtering data used. A significant focuses of the paper is the usage and validation of atomic data (resent metastable-resolved dataset from ADAS) for interpretation of Cr spectroscopy. Initial population of quasi-metastable state was fitted by matching the modeling with the experimental line intensity profiles.

  1. La sfida al labirinto sessuale. L’eros nell’opera di Italo Calvino

    Directory of Open Access Journals (Sweden)

    Elio Baldi

    2012-12-01

    Full Text Available The Challenge of the Sexual Labyrinth Sensuality in the Work of Italo CalvinoIn this article, the novels, stories and essays of Italo Calvino are being studied from the perspective of sensuality and Eros. In literary criticism Calvino’s work is rarely being associated with sexuality, even though the subject did fuel the imagination of the writer himself. Calvino recognized the importance of the theme of sexuality in literature as well as the challenge inherent in trying to depict faithfully a similar ineffable subject, that has, moreover, been covered by society under a thick layer of clichés and repetitive language and therefore been emptied of meaning. The importance of a non-banal, renewing sexuality in literature inspired Calvino to experiment in a light, humorous, surprising way with a myriad of forms of literary sensuality. Calvino has searched Eros in space, as the prime mover in evolution, amongst animals and celestial bodies (instead of the usual heavenly bodies, in rituals and objects, in the heads of his characters, but seldom there where the reader would expect it to be. In a mild and often indirect way Calvino integrates his reflections on the subject in his short stories and comments on the role of sexuality in modern society and literature.

  2. Asynchronous gaze-independent event-related potential-based brain-computer interface.

    Science.gov (United States)

    Aloise, Fabio; Aricò, Pietro; Schettini, Francesca; Salinari, Serenella; Mattia, Donatella; Cincotti, Febo

    2013-10-01

    In this study a gaze independent event related potential (ERP)-based brain computer interface (BCI) for communication purpose was combined with an asynchronous classifier endowed with dynamical stopping feature. The aim was to evaluate if and how the performance of such asynchronous system could be negatively affected in terms of communication efficiency and robustness to false positives during the intentional no-control state. The proposed system was validated with the participation of 9 healthy subjects. A comparison was performed between asynchronous and synchronous classification technique outputs while users were controlling the same gaze independent BCI interface. The performance of both classification techniques were assessed both off-line and on-line by means of the efficiency metric introduced by Bianchi et al. (2007). This latter metric allows to set a different misclassification cost for wrong classifications and abstentions. Robustness was evaluated as the rate of false positives occurring during voluntary no-control states. The asynchronous classifier did not exhibited significantly higher accuracy or lower error rate with respect to the synchronous classifier (accuracy: 74.66% versus 87.96%, error rate: 7.11% versus 12.04% respectively). However, the on-line and off-line analysis revealed that the communication efficiency was significantly improved (pinterface is a promising solution to be further explored in order to increase the general usability of ERP-based BCI systems designed for severely disabled people with an impairment of the voluntary control of eye movements. In fact, the asynchronous classifier can improve communication efficiency automatically adapting the number of stimulus repetitions to the current user's state and suspending the control if he/she does not intend to select an item. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. Automatic temporal expectancy: a high-density event-related potential study.

    Directory of Open Access Journals (Sweden)

    Giovanni Mento

    Full Text Available How we compute time is not fully understood. Questions include whether an automatic brain mechanism is engaged in temporally regular environmental structure in order to anticipate events, and whether this can be dissociated from task-related processes, including response preparation, selection and execution. To investigate these issues, a passive temporal oddball task requiring neither time-based motor response nor explicit decision was specifically designed and delivered to participants during high-density, event-related potentials recording. Participants were presented with pairs of audiovisual stimuli (S1 and S2 interspersed with an Inter-Stimulus Interval (ISI that was manipulated according to an oddball probabilistic distribution. In the standard condition (70% of trials, the ISI lasted 1,500 ms, while in the two alternative, deviant conditions (15% each, it lasted 2,500 and 3,000 ms. The passive over-exposition to the standard ISI drove participants to automatically and progressively create an implicit temporal expectation of S2 onset, reflected by the time course of the Contingent Negative Variation response, which always peaked in correspondence to the point of S2 maximum expectation and afterwards inverted in polarity towards the baseline. Brain source analysis of S1- and ISI-related ERP activity revealed activation of sensorial cortical areas and the supplementary motor area (SMA, respectively. In particular, since the SMA time course synchronised with standard ISI, we suggest that this area is the major cortical generator of the temporal CNV reflecting an automatic, action-independent mechanism underlying temporal expectancy.

  4. An Event-Related Potential Examination of Contour Integration Deficits in Schizophrenia

    Directory of Open Access Journals (Sweden)

    Pamela D Butler

    2013-03-01

    Full Text Available Perceptual organization, which refers to the ability to integrate fragments of stimuli to form a representation of a whole edge, part, or object, is impaired in schizophrenia. A contour integration paradigm, involving detection of a set of Gabor patches forming an oval contour pointing to the right or left embedded in a field of randomly oriented Gabors, has been developed for use in clinical trials of schizophrenia. The purpose of the present study was to assess contributions of early and later stages of processing to deficits in contour integration, as well as to develop an event-related potential (ERP analog of this task. Twenty-one patients with schizophrenia and 28 controls participated. The Gabor elements forming the contours were given a low or high degree of orientational jitter, making it either easy or difficult to identify the direction in which the contour was pointing. ERP results showed greater negative peaks at ~165 (N1 component and ~270 ms for the low-jitter versus the high-jitter contours, with a much greater difference between jitter conditions at 270 ms. This later ERP component was previously termed Ncl for closure negativity. Source localization identified the Ncl in the lateral occipital object recognition area. Patients showed a significant decrease in the Ncl, but not N1, compared to controls, and this was associated with impaired behavioral ability to identify contours. In addition, an earlier negative peak was found at ~120 ms (termed N120 that differentiated jitter conditions, had a dorsal stream source, and differed between patients and controls. Patients also showed a deficit in the dorsal stream sensory P1 component. These results are in accord with impairments in distributed circuitry contributing to perceptual organization deficits and provide an ERP analog to the behavioral contour integration task.

  5. Event-related potential and eye tracking evidence of the developmental dynamics of face processing.

    Science.gov (United States)

    Meaux, Emilie; Hernandez, Nadia; Carteau-Martin, Isabelle; Martineau, Joëlle; Barthélémy, Catherine; Bonnet-Brilhault, Frédérique; Batty, Magali

    2014-04-01

    Although the wide neural network and specific processes related to faces have been revealed, the process by which face-processing ability develops remains unclear. An interest in faces appears early in infancy, and developmental findings to date have suggested a long maturation process of the mechanisms involved in face processing. These developmental changes may be supported by the acquisition of more efficient strategies to process faces (theory of expertise) and by the maturation of the face neural network identified in adults. This study aimed to clarify the link between event-related potential (ERP) development in response to faces and the behavioral changes in the way faces are scanned throughout childhood. Twenty-six young children (4-10 years of age) were included in two experimental paradigms, the first exploring ERPs during face processing, the second investigating the visual exploration of faces using an eye-tracking system. The results confirmed significant age-related changes in visual ERPs (P1, N170 and P2). Moreover, an increased interest in the eye region and an attentional shift from the mouth to the eyes were also revealed. The proportion of early fixations on the eye region was correlated with N170 and P2 characteristics, highlighting a link between the development of ERPs and gaze behavior. We suggest that these overall developmental dynamics may be sustained by a gradual, experience-dependent specialization in face processing (i.e. acquisition of face expertise), which produces a more automatic and efficient network associated with effortless identification of faces, and allows the emergence of human-specific social and communication skills. © 2014 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  6. Fluid Intelligence and Automatic Neural Processes in Facial Expression Perception: An Event-Related Potential Study.

    Science.gov (United States)

    Liu, Tongran; Xiao, Tong; Li, Xiaoyan; Shi, Jiannong

    2015-01-01

    The relationship between human fluid intelligence and social-emotional abilities has been a topic of considerable interest. The current study investigated whether adolescents with different intellectual levels had different automatic neural processing of facial expressions. Two groups of adolescent males were enrolled: a high IQ group and an average IQ group. Age and parental socioeconomic status were matched between the two groups. Participants counted the numbers of the central cross changes while paired facial expressions were presented bilaterally in an oddball paradigm. There were two experimental conditions: a happy condition, in which neutral expressions were standard stimuli (p = 0.8) and happy expressions were deviant stimuli (p = 0.2), and a fearful condition, in which neutral expressions were standard stimuli (p = 0.8) and fearful expressions were deviant stimuli (p = 0.2). Participants were required to concentrate on the primary task of counting the central cross changes and to ignore the expressions to ensure that facial expression processing was automatic. Event-related potentials (ERPs) were obtained during the tasks. The visual mismatch negativity (vMMN) components were analyzed to index the automatic neural processing of facial expressions. For the early vMMN (50-130 ms), the high IQ group showed more negative vMMN amplitudes than the average IQ group in the happy condition. For the late vMMN (320-450 ms), the high IQ group had greater vMMN responses than the average IQ group over frontal and occipito-temporal areas in the fearful condition, and the average IQ group evoked larger vMMN amplitudes than the high IQ group over occipito-temporal areas in the happy condition. The present study elucidated the close relationships between fluid intelligence and pre-attentive change detection on social-emotional information.

  7. Spatiotemporal cortical activation underlies the Müller-Lyer illusion: an event-related potentials study.

    Science.gov (United States)

    Zhang, Songyan; Du, Xue; Wu, Xin; Wei, Dongtao; Zhang, Meng; Qiu, Jiang

    2013-12-04

    Event-related brain potentials (ERPs) were used to examine the electrophysiological correlates of the visual illusion effect in the Müller-Lyer illusion tasks. The participants were presented with the context of a horizontal line with two symmetric inward-pointing arrowheads or outward-pointing arrowheads, and then, they were asked to indicate whether they perceived an increase or a decrease in the line length. The behavioral results showed that there were significant differences among the four types of tasks, which meant that participants could understand different mean illusion magnitudes. The ERP results showed that both the illusion-45 and the illusion-135 elicited a more negative ERP deflection (N180-280) than did the illusion-225 and illusion-315 between 180 and 280 ms. In addition, the strong illusion stimuli elicited a more positive ERP deflection (P280-450) than did the weak illusion stimuli between 280 and 450 ms after the onset of the stimuli. Dipole source analysis of the difference wave (illusion-135-illusion-225) indicated that one generator localized in the left lateral occipital cortex and the difference wave (illusion-45-illusion-135) indicated that one generator localized in the left lingual gyrus. Our results led us to conclude that the ERP deflection in the different illusory strength might be related to the theory of attention resource distribution or because of the inverse optics problem. Then, the early visual areas lateral occipital cortex and the lingual gyrus near to the visual cortex could contribute to integrated processing in the illusory contours and top-down control processing because of the visual experiences.

  8. Who Are the True Fans? Evidence from an Event-Related Potential Study

    Science.gov (United States)

    Ma, Qingguo; Jin, Jia; Yuan, Ruixian; Zhang, Wuke

    2015-01-01

    Fans of celebrities commonly exist in modern society. Researchers from social science have been concerned with this problem for years. Furthermore, such researchers have attempted to measure people’s involvement with celebrities in various ways. However, no study measured the degree of addiction to a specific celebrity at the neurological level. Therefore, the current study employed visually evoked event related potentials (ERPs) to examine people’s attitude toward celebrities by comparing different brain activities of fans and non-fans when they were shown a set of photos. These photos include a specific celebrity, a familiar person, a stranger and a butterfly. Furthermore, to examine the validity of the detected neural index, we also investigated the correlation between brain activity and the score of the Celebrity Attitude Scale (CAS), which was a questionnaire used to explore people’s attitude toward celebrities at behavioral level. Two groups of subjects were asked to complete an implicit task, i.e., to press a button when a picture of a butterfly appeared. Results revealed that fans showed significant positive N2 and P300 deflection when viewing the photos of their favorite celebrity, whereas in the non-fan group, the subjects only showed larger P300 amplitude as a response to the celebrity’s photos. Furthermore, a positive correlation between P300 amplitude elicited by the stimuli of a celebrity face and CAS scores was also observed. These findings indicated fan attitude to a specific celebrity can also be observed at the neurological level and suggested the potential utility of using ERP component as an index of fandom involvement. PMID:26057891

  9. Attention effects on auditory scene analysis: insights from event-related brain potentials.

    Science.gov (United States)

    Spielmann, Mona Isabel; Schröger, Erich; Kotz, Sonja A; Bendixen, Alexandra

    2014-01-01

    Sounds emitted by different sources arrive at our ears as a mixture that must be disentangled before meaningful information can be retrieved. It is still a matter of debate whether this decomposition happens automatically or requires the listener's attention. These opposite positions partly stem from different methodological approaches to the problem. We propose an integrative approach that combines the logic of previous measurements targeting either auditory stream segregation (interpreting a mixture as coming from two separate sources) or integration (interpreting a mixture as originating from only one source). By means of combined behavioral and event-related potential (ERP) measures, our paradigm has the potential to measure stream segregation and integration at the same time, providing the opportunity to obtain positive evidence of either one. This reduces the reliance on zero findings (i.e., the occurrence of stream integration in a given condition can be demonstrated directly, rather than indirectly based on the absence of empirical evidence for stream segregation, and vice versa). With this two-way approach, we systematically manipulate attention devoted to the auditory stimuli (by varying their task relevance) and to their underlying structure (by delivering perceptual tasks that require segregated or integrated percepts). ERP results based on the mismatch negativity (MMN) show no evidence for a modulation of stream integration by attention, while stream segregation results were less clear due to overlapping attention-related components in the MMN latency range. We suggest future studies combining the proposed two-way approach with some improvements in the ERP measurement of sequential stream segregation.

  10. An event-related potentials study on selective attention modulated by vestibular stimulation.

    Science.gov (United States)

    Wang, Lin-Jie; Wei, Jin-he; Zhang, Dan; Dong, Wei-jun; Guo, Jian-ping; Hu, Mao-qi

    2004-04-01

    To explore the dynamic change of the late attentional selection process under linearly varied vestibular stimuli using event-related potentials (ERPs) technique. Thirty-three subjects participated in the experiment. They were exposed to vestibular stimulation of constant angular velocity rotation (10 degrees/s) and four levels of constant angular acceleration rotation, the acceleration was 0.6 degrees/s2, 0.8 degrees/s2, 1.0 degrees/s2, 1.2 degrees/s2 respectively. The same auditory go/no-go cognitive task was done during the stimulation. The task involved verbally given Chinese digit number from two to nine with 1000 ms random interval. Subjects were asked to push the button for the odd numbers (target) and withhold to the even numbers (non-target). Compared with control and different level of constant angular acceleration rotation, the N2 amplitude of non-target ERPs (NT-ERPs) decreased significantly over anterior-central scalp during 10 degrees/s constant rotation, but the N2 amplitude of target ERPs (T-ERPs) reduced significantly only at F4, F(Z) and T4 sites. The P3 latency of T-ERPs decreased significantly in 10 degrees/s constant rotation in contrast with control. Under four different acceleration level, the P3 latency of T-ERPs was relatively longer in 0.8 degrees/s2 and 1.0 degrees/s2, but shorter in 0.6 degrees/s2 and 1.2 degrees/s2. Constant angular velocity rotation had an activating effect on late attentional selection process. In contrast to the activation effect of constant angular velocity rotation, constant angular acceleration had an inhibition effect on the cognitive processes and this inhibition effect may have several levels.

  11. Incidence and Risk Factors for Adverse Events Related to Image-Guided Liver Biopsy.

    Science.gov (United States)

    Boyum, James H; Atwell, Thomas D; Schmit, Grant D; Poterucha, John J; Schleck, Cathy D; Harmsen, W Scott; Kamath, Patrick S

    2016-03-01

    To determine the incidence of major adverse events related to a large volume of image-guided liver biopsies performed at our institution over a 12-year period and to identify risk factors for major bleeding events. A retrospective analysis of an internally maintained biopsy registry was performed. The analysis revealed that 6613 image-guided liver biopsies were performed in 5987 adult patients between December 7, 2001, and December 31, 2013. Liver biopsies were performed using real-time ultrasound guidance and a spring-loaded biopsy device, with rare exceptions. Adverse events considered major and included in this study were hematoma, infection, pneumothorax, hemothorax, and death. Using data from the biopsy registry, we evaluated statistically significant risk factors (Pliver biopsy, including coagulation status, biopsy technique, and medications. A total of 49 acute and delayed major adverse events (0.7%) occurred after 6613 liver biopsy events. The incidence of hematoma requiring transfusion and/or angiographic intervention was 0.5% (34 of 6613). The incidence of infection was 0.1% (8 of 6613), and that of hemothorax was 0.06% (4 of 6613). No patient (0%) incurred a pneumothorax after biopsy. Three patients (0.05%) died within 30 days of liver biopsy, 1 being directly related to biopsy. Thirty-eight of 46 major adverse events (83%) presented acutely (within 24 hours). More than 2 biopsy passes, platelets 50,000/μL or less, and female sex were statistically significant risk factors for postbiopsy hemorrhage. Image-guided liver biopsy performed by subspecialized interventionalists at a tertiary medical center is safe when the platelet count is greater than 50,000/μL. With appreciation of specific risk factors, safety outcomes of this procedure can be optimized in both general and specialized centers. Copyright © 2016 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

  12. Object substitution masking in schizophrenia: an event-related potential analysis.

    Science.gov (United States)

    Wynn, Jonathan K; Mathis, Kristopher I; Ford, Judith; Breitmeyer, Bruno G; Green, Michael F

    2013-01-01

    Schizophrenia patients exhibit deficits on visual processing tasks, including visual backward masking, and these impairments are related to deficits in higher-level processes. In the current study we used electroencephalography techniques to examine successive stages and pathways of visual processing in a specialized masking paradigm, four-dot masking, which involves masking by object substitution. Seventy-six schizophrenia patients and 66 healthy controls had event-related potentials (ERPs) recorded during four-dot masking. Target visibility was manipulated by changing stimulus onset asynchrony (SOA) between the target and mask, such that performance decreased with increasing SOA. Three SOAs were used: 0, 50, and 100 ms. The P100 and N100 perceptual ERPs were examined. Additionally, the visual awareness negativity (VAN) to correct vs. incorrect responses, an index of reentrant processing, was examined for SOAs 50 and 100 ms. Results showed that patients performed worse than controls on the behavioral task across all SOAs. The ERP results revealed that patients had significantly smaller P100 and N100 amplitudes, though there was no effect of SOA on either component in either group. In healthy controls, but not patients, N100 amplitude correlated significantly with behavioral performance at SOAs where masking occurred, such that higher accuracy correlated with a larger N100. Healthy controls, but not patients, exhibited a larger VAN to correct vs. incorrect responses. The results indicate that the N100 appears to be related to attentional effort in the task in controls, but not patients. Considering that the VAN is thought to reflect reentrant processing, one interpretation of the findings is that patients' lack of VAN response and poorer performance may be related to dysfunctional reentrant processing.

  13. Using event related potentials to identify a user's behavioural intention aroused by product form design.

    Science.gov (United States)

    Ding, Yi; Guo, Fu; Zhang, Xuefeng; Qu, Qingxing; Liu, Weilin

    2016-07-01

    The capacity of product form to arouse user's behavioural intention plays a decisive role in further user experience, even in purchase decision, while traditional methods rarely give a fully understanding of user experience evoked by product form, especially the feeling of anticipated use of product. Behavioural intention aroused by product form designs has not yet been investigated electrophysiologically. Hence event related potentials (ERPs) were applied to explore the process of behavioural intention when users browsed different smart phone form designs with brand and price not taken into account for mainly studying the brain activity evoked by variety of product forms. Smart phone pictures with different anticipated user experience were displayed with equiprobability randomly. Participants were asked to click the left mouse button when certain picture gave them a feeling of behavioural intention to interact with. The brain signal of each participant was recorded by Curry 7.0. The results show that pictures with an ability to arouse participants' behavioural intention for further experience can evoke enhanced N300 and LPPs (late positive potentials) in central-parietal, parietal and occipital regions. The scalp topography shows that central-parietal, parietal and occipital regions are more activated. The results indicate that the discrepancy of ERPs can reflect the neural activities of behavioural intention formed or not. Moreover, amplitude of ERPs occurred in corresponding brain areas can be used to measure user experience. The exploring of neural correlated with behavioural intention provide an accurate measurement method of user's perception and help marketers to know which product can arouse users' behavioural intention, maybe taken as an evaluating indicator of product design. Copyright © 2016 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  14. Disentangling the Attention Network Test: Behavioral, Event Related Potentials and neural source analyses.

    Directory of Open Access Journals (Sweden)

    Alejandro eGalvao-Carmona

    2014-10-01

    Full Text Available Background. The study of the attentional system remains a challenge for current neuroscience. The Attention Network Test (ANT was designed to study simultaneously three different attentional networks (alerting, orienting and executive based in subtraction of different experimental conditions. However, some studies recommend caution with these calculations due to the interactions between the attentional networks. In particular, it is highly relevant that several interpretations about attentional impairment have arisen from these calculations in diverse pathologies. Event Related Potentials (ERPs and neural source analysis can be applied to disentangle the relationships between these attentional networks not specifically shown by behavioural measures. Results. This study shows that there is a basic level of alerting (tonic alerting in the no cue condition, represented by a slow negative trend in the ERP trace prior to the onset of the target stimuli. A progressive increase in the CNV amplitude related to the amount of information provided by the cue conditions is also shown. Neural source analysis reveals specific modulations of the CNV related to a task-related expectancy presented in the no cue condition; a late modulation triggered by the central cue condition and probably representing a generic motor preparation; and an early and late modulation for spatial cue condition suggesting specific motor and sensory preactivation. Finally, the first component in the information processing of the target stimuli modulated by the interaction between orienting network and the executive system can be represented by N1. Conclusions. The ANT is useful as a paradigm to study specific attentional mechanisms and their interactions. However, calculation of network effects is based in subtractions with non-comparable experimental conditions, as evidenced by the present data, which can induce misinterpretations in the study of the attentional capacity in human

  15. Differential beta-band event-related desynchronization during categorical action sequence planning.

    Science.gov (United States)

    Park, Hame; Kim, June Sic; Chung, Chun Kee

    2013-01-01

    A primate study reported the existence of neurons from the dorso-lateral prefrontal cortex which fired prior to executing categorical action sequences. The authors suggested these activities may represent abstract level information. Here, we aimed to find the neurophysiological representation of planning categorical action sequences at the population level in healthy humans. Previous human studies have shown beta-band event-related desynchronization (ERD) during action planning in humans. Some of these studies showed different levels of ERD according to different types of action preparation. Especially, the literature suggests that variations in cognitive factors rather than physical factors (force, direction, etc) modulate the level of beta-ERD. We hypothesized that the level of beta-band power will differ according to planning of different categorical sequences. We measured magnetoencephalography (MEG) from 22 subjects performing 11 four-sequence actions--each consisting of one or two of three simple actions--in 3 categories; 'Paired (ooxx)', 'Alternative (oxox)' and 'Repetitive (oooo)' ('o' and 'x' each denoting one of three simple actions). Time-frequency representations were calculated for each category during the planning period, and the corresponding beta-power time-courses were compared. We found beta-ERD during the planning period for all subjects, mostly in the contralateral fronto-parietal areas shortly after visual cue onset. Power increase (transient rebound) followed ERD in 20 out of 22 subjects. Amplitudes differed among categories in 20 subjects for both ERD and transient rebound. In 18 out of 20 subjects 'Repetitive' category showed the largest ERD and rebound. The current result suggests that beta-ERD in the contralateral frontal/motor/parietal areas during planning is differentiated by the category of action sequences.

  16. Recognition Memory in Amnestic-Mild Cognitive Impairment: Insights from Event-Related Potentials

    Directory of Open Access Journals (Sweden)

    David A Wolk

    2013-12-01

    Full Text Available Episodic memory loss is the hallmark cognitive dysfunction associated with Alzheimer’s Disease (AD. Amnestic Mild Cognitive Impairment (a-MCI frequently represents a transitional stage between normal aging and early AD. A better understanding of the qualitative features of memory loss in a-MCI may have important implications for predicting those most likely to harbor AD-related pathology and for disease monitoring. Dual process models of memory argue that recognition memory is subserved by the dissociable processes of recollection and familiarity. Work studying recognition memory in a-MCI from this perspective has been controversial, particularly with regard to the integrity of familiarity. Event-related potentials (ERPs offer an alternative means for assessing these functions without the associated assumptions of behavioral estimation methods. ERPs were recorded while a-MCI patients and cognitively normal (CN age-matched adults performed a recognition memory task. When retrieval success was measured (hits versus correct rejections in which performance was matched by group, a-MCI patients displayed similar neural correlates to that of the CN group, including modulation of the FN400 and the late parietal complex (LPC which are thought to index familiarity and recollection, respectively. Alternatively, when the integrity of these components were measured based on retrieval attempts (studied versus unstudied items, a-MCI patients displayed a reduced FN400 and LPC. Furthermore, modulation of the FN400 correlated with a behavioral estimate of familiarity and the LPC with a behavioral estimates of recollection obtained in a separate experiment in the same individuals, consistent with the proposed mappings of these indices. These results support a global decline of recognition memory in a-MCI, which suggests that the memory loss of prodromal AD may be qualitatively distinct from normal aging.

  17. Recognition memory for emotional faces in amnestic mild cognitive impairment: an event-related potential study.

    Science.gov (United States)

    Schefter, Maria; Werheid, Katja; Almkvist, Ove; Lönnqvist-Akenine, Ulrika; Kathmann, Norbert; Winblad, Bengt

    2013-01-01

    This study examined the temporal course of emotional face recognition in amnestic mild cognitive impairment (aMCI). Patients and healthy controls (HC) performed a face recognition task, giving old/new responses to previously studied and novel faces displaying a negative or neutral expression. In aMCI patients, recognition accuracy was preserved for negative faces. Event-related potentials (ERPs) revealed disease-related changes in early perceptual components but not in ERP indices of explicit recognition. Specifically, aMCI patients showed impaired recognition effects for negative faces on the amplitudes of N170 and P2, suggesting deficient memory-related processing of negative faces at the stage of structural encoding and during an early recognition stage at which faces are individuated, respectively. Moreover, while a right-lateralized emotion effect specifically observed for correctly recognized faces on the amplitude of N170 was absent in aMCI, a similar emotion effect for successfully recognized faces on P2 was preserved in the patients, albeit with a different distribution. This suggests that in aMCI facilitated processing of successfully recognized emotional faces starts later in the processing sequence. Nonetheless, an early frontal old/new effect confined to negative faces and a parietal old/new effect unaffected by facial emotion were observed in both groups. This indicates that familiarity and conceptual priming processes may specifically contribute to recognition of negative faces in older adults and that aMCI patients can recruit the same retrieval mechanisms as controls, despite disease-related changes on early perceptual ERP components.

  18. Fluid Intelligence and Automatic Neural Processes in Facial Expression Perception: An Event-Related Potential Study.

    Directory of Open Access Journals (Sweden)

    Tongran Liu

    Full Text Available The relationship between human fluid intelligence and social-emotional abilities has been a topic of considerable interest. The current study investigated whether adolescents with different intellectual levels had different automatic neural processing of facial expressions. Two groups of adolescent males were enrolled: a high IQ group and an average IQ group. Age and parental socioeconomic status were matched between the two groups. Participants counted the numbers of the central cross changes while paired facial expressions were presented bilaterally in an oddball paradigm. There were two experimental conditions: a happy condition, in which neutral expressions were standard stimuli (p = 0.8 and happy expressions were deviant stimuli (p = 0.2, and a fearful condition, in which neutral expressions were standard stimuli (p = 0.8 and fearful expressions were deviant stimuli (p = 0.2. Participants were required to concentrate on the primary task of counting the central cross changes and to ignore the expressions to ensure that facial expression processing was automatic. Event-related potentials (ERPs were obtained during the tasks. The visual mismatch negativity (vMMN components were analyzed to index the automatic neural processing of facial expressions. For the early vMMN (50-130 ms, the high IQ group showed more negative vMMN amplitudes than the average IQ group in the happy condition. For the late vMMN (320-450 ms, the high IQ group had greater vMMN responses than the average IQ group over frontal and occipito-temporal areas in the fearful condition, and the average IQ group evoked larger vMMN amplitudes than the high IQ group over occipito-temporal areas in the happy condition. The present study elucidated the close relationships between fluid intelligence and pre-attentive change detection on social-emotional information.

  19. Isolating event-related potential components associated with voluntary control of visuo-spatial attention.

    Science.gov (United States)

    McDonald, John J; Green, Jessica J

    2008-08-28

    Attention-directing cues presented at fixation evoke several lateralized event-related potential (ERP) components prior to the onset of visual targets. These components have been associated with the control of visuo-spatial attention, but the neuro-cognitive operations and neural generators of the components are still largely unknown. Here, we isolated cue-elicited ERP activity in different ways to home in on different neuro-cognitive operations and to gain a better understanding about the possible neuroanatomical sources of the cue-elicited ERP activities. To isolate lateralized cue-ERP activity, we compared shift-left and shift-right cue ERPs to shift-up cue ERPs. To measure all of the ERP activity related to attentional control, including spatially nonspecific activity that is removed in the process of isolating lateralized cue-ERP components, we compared shift-cue ERPs to neutral-cue (i.e., no-shift) ERPs. Isolated lateralized-ERP activity was seen in the contralateral-occipital lobe in the early phase of the cue-target interval and in the ipsilateral-occipital lobe in the late phase. The later, ipsilateral activity indicates that the late directing attention positivity (LDAP) reflected processing of the to-be-ignored location. The neutral-cue isolation revealed a shift-related positivity over posterior scalp regions and a shift-related negativity over more anterior scalp regions. The spatio-temporal sequence of shift-related activity observed on the scalp, together with estimates of distributed source activity underlying the shift-related ERP components, indicated that frontal and parietal regions of cortex participated in the control of attention and led to pre-target biasing in visual cortical areas.

  20. Automatic Conflict Monitoring by Event-Related Potentials Could be used to Estimate Visual Acuity Levels.

    Science.gov (United States)

    Huang, Wenwen; Liu, Sinan; Luo, Bin; Meng, Huanhuan; Ji, Mengmeng; Li, Maojuan; Chen, Xiping; Tao, Luyang

    2018-03-15

    Numerous studies have explored the physical attribute features or face perceptions in conflict processing, while complicate gradient conflicts were rarely discussed. The aim of the study was to discuss the relationship between the event-related potential (ERP) component features and different visual acuity levels by using the modified S1-S2 task under non-attention status. Three visual acuity levels were applied, each with four orientations of "E" optotype stimuli randomly presented in the center of the visual field while participants were required to concentrate on listening to stories. The results showed that the amplitudes of P1 and P3 as well as difference P3 were larger in supra-threshold condition. In threshold condition, larger amplitudes for both N2 and difference N2 exhibited in frontal and central areas. In sub-threshold condition, there was no endogenous component elicited by mismatch stimuli except smaller anterior N1. Meanwhile, the specific distributions of N1 and N2 were presented and compared with previous face processing. The findings showed that visual conflict processing took place not only at an early stage but also at the late period, which might be as the consequences of interaction between conflict strength and involuntary attention. We concluded that automatic conflict detecting of visual icons by the serial ERP components could distinguish different visual acuity levels. The involvement of endogenous components could reveal the specific mechanism of more precise and fine conflict identification of complex physical attributes under non-attention status, furthermore could be used as valid markers to estimate the magnitude of visual acuity objectively. Copyright © 2018 IBRO. Published by Elsevier Ltd. All rights reserved.

  1. Who Are the True Fans? Evidence from an Event-Related Potential Study.

    Science.gov (United States)

    Ma, Qingguo; Jin, Jia; Yuan, Ruixian; Zhang, Wuke

    2015-01-01

    Fans of celebrities commonly exist in modern society. Researchers from social science have been concerned with this problem for years. Furthermore, such researchers have attempted to measure people's involvement with celebrities in various ways. However, no study measured the degree of addiction to a specific celebrity at the neurological level. Therefore, the current study employed visually evoked event related potentials (ERPs) to examine people's attitude toward celebrities by comparing different brain activities of fans and non-fans when they were shown a set of photos. These photos include a specific celebrity, a familiar person, a stranger and a butterfly. Furthermore, to examine the validity of the detected neural index, we also investigated the correlation between brain activity and the score of the Celebrity Attitude Scale (CAS), which was a questionnaire used to explore people's attitude toward celebrities at behavioral level. Two groups of subjects were asked to complete an implicit task, i.e., to press a button when a picture of a butterfly appeared. Results revealed that fans showed significant positive N2 and P300 deflection when viewing the photos of their favorite celebrity, whereas in the non-fan group, the subjects only showed larger P300 amplitude as a response to the celebrity's photos. Furthermore, a positive correlation between P300 amplitude elicited by the stimuli of a celebrity face and CAS scores was also observed. These findings indicated fan attitude to a specific celebrity can also be observed at the neurological level and suggested the potential utility of using ERP component as an index of fandom involvement.

  2. Distinct features of auditory steady-state responses as compared to transient event-related potentials.

    Directory of Open Access Journals (Sweden)

    Li Zhang

    Full Text Available Transient event-related potentials (ERPs and steady-state responses (SSRs have been popularly employed to investigate the function of the human brain, but their relationship still remains a matter of debate. Some researchers believed that SSRs could be explained by the linear summation of successive transient ERPs (superposition hypothesis, while others believed that SSRs were the result of the entrainment of a neural rhythm driven by the periodic repetition of a sensory stimulus (oscillatory entrainment hypothesis. In the present study, taking auditory modality as an example, we aimed to clarify the distinct features of SSRs, evoked by the 40-Hz and 60-Hz periodic auditory stimulation, as compared to transient ERPs, evoked by a single click. We observed that (1 SSRs were mainly generated by phase synchronization, while late latency responses (LLRs in transient ERPs were mainly generated by power enhancement; (2 scalp topographies of LLRs in transient ERPs were markedly different from those of SSRs; (3 the powers of both 40-Hz and 60-Hz SSRs were significantly correlated, while they were not significantly correlated with the N1 power in transient ERPs; (4 whereas SSRs were dominantly modulated by stimulus intensity, middle latency responses (MLRs were not significantly modulated by both stimulus intensity and subjective loudness judgment, and LLRs were significantly modulated by subjective loudness judgment even within the same stimulus intensity. All these findings indicated that high-frequency SSRs were different from both MLRs and LLRs in transient ERPs, thus supporting the possibility of oscillatory entrainment hypothesis to the generation of SSRs. Therefore, SSRs could be used to explore distinct neural responses as compared to transient ERPs, and help us reveal novel and reliable neural mechanisms of the human brain.

  3. Event-related potential studies of outcome processing and feedback-guided learning

    Directory of Open Access Journals (Sweden)

    René eSan Martín

    2012-11-01

    Full Text Available In order to control behavior in an adaptive manner the brain has to learn how some situations and actions predict positive or negative outcomes. During the last decade cognitive neuroscientists have shown that the brain is able to evaluate and learn from outcomes within a few hundred milliseconds of their occurrence. This research has been primarily focused on the feedback-related negativity (FRN and the P3, two event-related potential (ERP components that are elicited by outcomes. The FRN is a frontally distributed negative-polarity ERP component that typically reaches its maximal amplitude 250 ms after outcome presentation and tends to be larger for negative than for positive outcomes. The FRN has been associated with activity in the anterior cingulate cortex. The P3 (~300-600 ms is a parietally distributed positive-polarity ERP component that tends to be larger for large magnitude than for small magnitude outcomes. The neural sources of the P3 are probably distributed over different regions of the cortex. This paper examines the theories that have been proposed to explain the functional role of these two ERP components during outcome processing. Special attention is paid to extant literature addressing how these ERP components are modulated by outcome valence (negative vs. positive, outcome magnitude (large vs. small, outcome probability (unlikely vs. likely and behavioral adjustment. The literature offers few generalizable conclusions, but is beset with a number of inconsistencies across studies. This paper discusses the potential reasons for these inconsistencies and points out some challenges that will shape the field over the next decade.

  4. Event-related potential correlates of performance-monitoring in a lateralized time-estimation task.

    Directory of Open Access Journals (Sweden)

    Theo O J Gruendler

    Full Text Available Performance-monitoring as a key function of cognitive control covers a wide range of diverse processes to enable goal directed behavior and to avoid maladjustments. Several event-related brain potentials (ERP are associated with performance-monitoring, but their conceptual background differs. For example, the feedback-related negativity (FRN is associated with unexpected performance feedback and might serve as a teaching signal for adaptational processes, whereas the error-related negativity (ERN is associated with error commission and subsequent behavioral adaptation. The N2 is visible in the EEG when the participant successfully inhibits a response following a cue and thereby adapts to a given stop-signal. Here, we present an innovative paradigm to concurrently study these different performance-monitoring-related ERPs. In 24 participants a tactile time-estimation task interspersed with infrequent stop-signal trials reliably elicited all three ERPs. Sensory input and motor output were completely lateralized, in order to estimate any hemispheric processing preferences for the different aspects of performance monitoring associated with these ERPs. In accordance with the literature our data suggest augmented inhibitory capabilities in the right hemisphere given that stop-trial performance was significantly better with left- as compared to right-hand stop-signals. In line with this, the N2 scalp distribution was generally shifted to the right in addition to an ipsilateral shift in relation to the response hand. Other than that, task lateralization affected neither behavior related to error and feedback processing nor ERN or FRN. Comparing the ERP topographies using the Global Map Dissimilarity index, a large topographic overlap was found between all considered components.With an evenly distributed set of trials and a split-half reliability for all ERP components ≥.85 the task is well suited to efficiently study N2, ERN, and FRN concurrently which

  5. Cerebral lesions and event-related potential P300 using positron emission tomography (PET)

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, Yasujiro; Okamoto, Kazuma; Tanaka, Makoto; Kondoh, Susumu; Hirai, Shunsaku (Gunma Univ., Maebashi (Japan). School of Medicine)

    1993-06-01

    To determine what lesions are involved in prolonging event-related potential P300 latency, regional cerebral blood flow (rCBF) and metabolism were investigated by positron emission tomography (PET) in a total of 40 patients with neurologic diseases (12 with chronic cerebrovascular disorder, 9 with spino-cerebellar degeneration, 4 with Alzheimer's type dementia, 4 with amyotrophic lateral sclerosis, and 11 with miscellaneous diseases). There was inverse correlation between rCBF and P300 latency in terms of any of the whole, left, and right hemispheres: P300 latency was associated with decreased rCBF. This was more noticeable in the cerebral cortex than white matter and in the right than left hemisphere, although there was no significant difference between them. In none of the regions, however, was there significant correlation between cerebral oxygen consumption and P300 latency. When the right and left frontal, temporal, parietal and occipital cortexes, thalamus, putamen, and caudatum were examined as regions of interest, there was significantly inverse correlation between rCBF and P300 latency in all regions except for the occipital cortex. This was more noticeable on the right than the left side, although no significant difference was observed. Cerebral oxygen consumption in these lesions did not correlate with P300 latency. In the study on bilateral rCBF difference, decreased rCBF confined to the right parietal lobe, bilateral thalamus and bilateral temporal lobes was found to be associated with a significantly prolonged P300 latency. Thus, rCBF in these regions seemed to be particularly responsible for P300 latency. (N.K.).

  6. Brain Network Activation Analysis Utilizing Spatiotemporal Features for Event Related Potentials Classification

    Directory of Open Access Journals (Sweden)

    Yaki Stern

    2016-12-01

    Full Text Available The purpose of this study was to introduce an improved tool for automated classification of event-related potentials (ERPs using spatiotemporally parcellated events incorporated into a functional brain network activation (BNA analysis. The auditory oddball ERP paradigm was selected to demonstrate and evaluate the improved tool. Methods: The ERPs of each subject were decomposed into major dynamic spatiotemporal events. Then, a set of spatiotemporal events representing the group was generated by aligning and clustering the spatiotemporal events of all individual subjects. The temporal relationship between the common group events generated a network, which is the spatiotemporal reference BNA model. Scores were derived by comparing each subject’s spatiotemporal events to the reference BNA model and were then entered into a support vector machine classifier to classify subjects into relevant subgroups. The reliability of the BNA scores (test-retest repeatability using intraclass correlation and their utility as a classification tool were examined in the context of Target-Novel classification. Results: BNA intraclass correlation values of repeatability ranged between 0.51 and 0.82 for the known ERP components N100, P200 and P300. Classification accuracy was high when the trained data were validated on the same subjects for different visits (AUCs 0.93 and 0.95. The classification accuracy remained high for a test group recorded at a different clinical center with a different recording system (AUCs 0.81, 0.85 for 2 visits. Conclusion: The improved spatiotemporal BNA analysis demonstrates high classification accuracy. The BNA analysis method holds promise as a tool for diagnosis, follow-up and drug development associated with different neurological conditions.

  7. Mind wandering and retrieval from episodic memory: a pilot event-related potential study.

    Science.gov (United States)

    Riby, Leigh Martin; Smallwood, Jonathan; Gunn, Valerie P

    2008-06-01

    The present study investigated the effects of mind wandering (task-unrelated thought) on the subcomponents of episodic memory as reflected by event-related potentials (ERPs). Specifically, individual differences in the pattern of ERP episodic 'old/new' effects (left-parietal, right-frontal and central-negativity effects) were examined across groups of participants experiencing either high or low frequencies of task-unrelated thought during encoding. Twenty participants studied lists of words and line drawings in one of two contexts (red versus green coloured boxes). At test, participants discriminated between target (old words or line drawings presented in one colour) and nontargets (old items from the other colour and new items). On completion of the memory task, participants completed the 'thinking' component of the Dundee Stress State Questionnaire to provide a retrospective measure of task-unrelated thought. Behavioural data indicated that irrespective of the presence of task-unrelated thought, participants were able to complete the memory task equally well. However, an analysis of ERPs across High and Low task-unrelated thought groups revealed differences in retrieval strategy. Those individuals with infrequent episodes of task-unrelated thought at study used a 'pure' recollection strategy (left-parietal effect only). Conversely, those participants experiencing frequent episodes of task-unrelated thought were unable to recollect the stimuli with ease, as indexed by a diminished parietal effect. As a consequence, these participants employed additional strategic processes for task completion, as indexed by an elevated amplitude of central negativity effects. These data are consistent with the decoupling hypothesis of mind wandering which suggests impaired recollection when attention becomes directed away from the task.

  8. Attention bias in earthquake-exposed survivors: an event-related potential study.

    Science.gov (United States)

    Zhang, Yan; Kong, Fanchang; Han, Li; Najam Ul Hasan, Abbasi; Chen, Hong

    2014-12-01

    The Chinese Wenchuan earthquake, which happened on the 28th of May in 2008, may leave deep invisible scars in individuals. China has a large number of children and adolescents, who tend to be most vulnerable because they are in an early stage of human development and possible post-traumatic psychological distress may have a life-long consequence. Trauma survivors without post-traumatic stress disorder (PTSD) have received little attention in previous studies, especially in event-related potential (ERP) studies. We compared the attention bias to threat stimuli between the earthquake-exposed group and the control group in a masked version of the dot probe task. The target probe presented at the same space location consistent with earthquake-related words was the congruent trial, while in the space location of neutral words was the incongruent trial. Thirteen earthquake-exposed middle school students without PTSD and 13 matched controls were included in this investigation. The earthquake-exposed group showed significantly faster RTs to congruent trials than to incongruent trials. The earthquake-exposed group produced significantly shorter C1 and P1 latencies and larger C1, P1 and P2 amplitudes than the control group. In particular, enhanced P1 amplitude to threat stimuli was observed in the earthquake-exposed group. These findings are in agreement with the prediction that earthquake-exposed survivors have an attention bias to threat stimuli. The traumatic event had a much greater effect on earthquake-exposed survivors even if they showed no PTSD symptoms than individuals in the controls. These results will provide neurobiological evidences for effective intervention and prevention to post-traumatic mental problems. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Who Are the True Fans? Evidence from an Event-Related Potential Study.

    Directory of Open Access Journals (Sweden)

    Qingguo Ma

    Full Text Available Fans of celebrities commonly exist in modern society. Researchers from social science have been concerned with this problem for years. Furthermore, such researchers have attempted to measure people's involvement with celebrities in various ways. However, no study measured the degree of addiction to a specific celebrity at the neurological level. Therefore, the current study employed visually evoked event related potentials (ERPs to examine people's attitude toward celebrities by comparing different brain activities of fans and non-fans when they were shown a set of photos. These photos include a specific celebrity, a familiar person, a stranger and a butterfly. Furthermore, to examine the validity of the detected neural index, we also investigated the correlation between brain activity and the score of the Celebrity Attitude Scale (CAS, which was a questionnaire used to explore people's attitude toward celebrities at behavioral level. Two groups of subjects were asked to complete an implicit task, i.e., to press a button when a picture of a butterfly appeared. Results revealed that fans showed significant positive N2 and P300 deflection when viewing the photos of their favorite celebrity, whereas in the non-fan group, the subjects only showed larger P300 amplitude as a response to the celebrity's photos. Furthermore, a positive correlation between P300 amplitude elicited by the stimuli of a celebrity face and CAS scores was also observed. These findings indicated fan attitude to a specific celebrity can also be observed at the neurological level and suggested the potential utility of using ERP component as an index of fandom involvement.

  10. How Social Ties Influence Consumer: Evidence from Event-Related Potentials.

    Directory of Open Access Journals (Sweden)

    Jing Luan

    Full Text Available A considerable amount of marketing research has reported that consumers are more saliently influenced by friends (strong social ties than by acquaintances and strangers (weak social ties. To shed light on the neural and psychological processes underlying such phenomenon, in this study we designed an amended S1-S2 paradigm (product-[reviewer-review] that is based on realistic consumer purchase experiences. After incoming all given information (product, reviewer, review, participants were required to state their purchase intentions. The neurocognitive and emotional processes related to friend and stranger stimuli were delineated to suggest how social ties influence consumers during their shopping processes. Larger P2 (fronto-central scalp areas and P3 (central and posterior-parietal scalp areas components under stranger condition were elicited successfully. These findings demonstrate that the cognitive and emotional processing of friend and stranger stimuli occurs at stages of neural activity, and can be indicated by the P2 and P3 components. Electrophysiological data also support the hypothesis that different neural and emotional processing magnitude and strength underlie friend and stranger effect in the context of consumer purchase. During this process, the perception of stimuli evoked P2, subsequently emotional processing and attention modulation were activated and indicated by P2 and P3. The friend dominated phenomenon can be interpreted as the result of distinctive neurocognitive and emotional processing magnitude, which suggests that psychological and emotional factors can guide consumer decision making. This study consolidates that event related potential (ERP methodology is likely to be a more sensitive method for investigating consumer behaviors. From the perspectives of management and marketing, our findings show that the P2 and P3 components can be employed as an indicator to probe the influential factors of consumer purchase

  11. Temporal Dynamics of Visual Attention Measured with Event-Related Potentials

    Science.gov (United States)

    Kashiwase, Yoshiyuki; Matsumiya, Kazumichi; Kuriki, Ichiro; Shioiri, Satoshi

    2013-01-01

    How attentional modulation on brain activities determines behavioral performance has been one of the most important issues in cognitive neuroscience. This issue has been addressed by comparing the temporal relationship between attentional modulations on neural activities and behavior. Our previous study measured the time course of attention with amplitude and phase coherence of steady-state visual evoked potential (SSVEP) and found that the modulation latency of phase coherence rather than that of amplitude was consistent with the latency of behavioral performance. In this study, as a complementary report, we compared the time course of visual attention shift measured by event-related potentials (ERPs) with that by target detection task. We developed a novel technique to compare ERPs with behavioral results and analyzed the EEG data in our previous study. Two sets of flickering stimulus at different frequencies were presented in the left and right visual hemifields, and a target or distracter pattern was presented randomly at various moments after an attention-cue presentation. The observers were asked to detect targets on the attended stimulus after the cue. We found that two ERP components, P300 and N2pc, were elicited by the target presented at the attended location. Time-course analyses revealed that attentional modulation of the P300 and N2pc amplitudes increased gradually until reaching a maximum and lasted at least 1.5 s after the cue onset, which is similar to the temporal dynamics of behavioral performance. However, attentional modulation of these ERP components started later than that of behavioral performance. Rather, the time course of attentional modulation of behavioral performance was more closely associated with that of the concurrently recorded SSVEPs analyzed. These results suggest that neural activities reflected not by either the P300 or N2pc, but by the SSVEPs, are the source of attentional modulation of behavioral performance. PMID:23976966

  12. Attentional Bias in Patients with Decompensated Tinnitus: Prima Facie Evidence from Event-Related Potentials.

    Science.gov (United States)

    Li, Zhicheng; Gu, Ruolei; Zeng, Xiangli; Zhong, Weifang; Qi, Min; Cen, Jintian

    2016-01-01

    Tinnitus refers to the auditory perception of sound in the absence of external sound or electric stimuli. The influence of tinnitus on cognitive processing is at the cutting edge of ongoing tinnitus research. In this study, we adopted an objective indicator of attentional processing, i.e. the mismatch negativity (MMN), to assess the attentional bias in patients with decompensated tinnitus. Three kinds of pure tones, D1 (8,000 Hz), S (8,500 Hz) and D2 (9,000 Hz), were used to induce event-related potentials (ERPs) in the normal ear. Employing the oddball paradigm, the task was divided into two blocks in which D1 and D2 were set as deviation stimuli, respectively. Only D2 induced a significant MMN in the tinnitus group, while neither D1 nor D2 was able to induce MMN in the control group. In addition, the ERPs in the left hemisphere, which were recorded within the time window of 90-150 ms (ERP 90-150 ms), were significantly higher than those in the right hemisphere in the tinnitus group, while no significant difference was observed in the control group. Lastly, the amplitude of ERP 90-150 ms in the tinnitus group was significantly higher than that in the control group. These findings suggest that patients with decompensated tinnitus showed automatic processing of acoustic stimuli, thereby indicating that these patients allocated more cognitive resources to acoustic stimulus processing. We suggest that the difficulty in disengaging or facilitated attention of patients might underlie this phenomenon. The limitations of the current study are discussed. © 2016 S. Karger AG, Basel.

  13. How Social Ties Influence Consumer: Evidence from Event-Related Potentials.

    Science.gov (United States)

    Luan, Jing; Yao, Zhong; Bai, Yan

    2017-01-01

    A considerable amount of marketing research has reported that consumers are more saliently influenced by friends (strong social ties) than by acquaintances and strangers (weak social ties). To shed light on the neural and psychological processes underlying such phenomenon, in this study we designed an amended S1-S2 paradigm (product-[reviewer-review]) that is based on realistic consumer purchase experiences. After incoming all given information (product, reviewer, review), participants were required to state their purchase intentions. The neurocognitive and emotional processes related to friend and stranger stimuli were delineated to suggest how social ties influence consumers during their shopping processes. Larger P2 (fronto-central scalp areas) and P3 (central and posterior-parietal scalp areas) components under stranger condition were elicited successfully. These findings demonstrate that the cognitive and emotional processing of friend and stranger stimuli occurs at stages of neural activity, and can be indicated by the P2 and P3 components. Electrophysiological data also support the hypothesis that different neural and emotional processing magnitude and strength underlie friend and stranger effect in the context of consumer purchase. During this process, the perception of stimuli evoked P2, subsequently emotional processing and attention modulation were activated and indicated by P2 and P3. The friend dominated phenomenon can be interpreted as the result of distinctive neurocognitive and emotional processing magnitude, which suggests that psychological and emotional factors can guide consumer decision making. This study consolidates that event related potential (ERP) methodology is likely to be a more sensitive method for investigating consumer behaviors. From the perspectives of management and marketing, our findings show that the P2 and P3 components can be employed as an indicator to probe the influential factors of consumer purchase intentions.

  14. Successful syllable detection in aphasia despite processing impairments as revealed by event-related potentials

    Directory of Open Access Journals (Sweden)

    Becker Frank

    2007-01-01

    Full Text Available Abstract Background The role of impaired sound and speech sound processing for auditory language comprehension deficits in aphasia is unclear. No electrophysiological studies of attended speech sound processing in aphasia have been performed for stimuli that are discriminable even for patients with severe auditory comprehension deficits. Methods Event-related brain potentials (ERPs were used to study speech sound processing in a syllable detection task in aphasia. In an oddball paradigm, the participants had to detect the infrequent target syllable /ta:/ amongst the frequent standard syllable /ba:/. 10 subjects with moderate and 10 subjects with severe auditory comprehension impairment were compared to 11 healthy controls. Results N1 amplitude was reduced indicating impaired primary stimulus analysis; N1 reduction was a predictor for auditory comprehension impairment. N2 attenuation suggests reduced attended stimulus classification and discrimination. However, all aphasic patients were able to discriminate the stimuli almost without errors, and processes related to the target identification (P3 were not significantly reduced. The aphasic subjects might have discriminated the stimuli by purely auditory differences, while the ERP results reveal a reduction of language-related processing which however did not prevent performing the task. Topographic differences between aphasic subgroups and controls indicate compensatory changes in activation. Conclusion Stimulus processing in early time windows (N1, N2 is altered in aphasics with adverse consequences for auditory comprehension of complex language material, while allowing performance of simpler tasks (syllable detection. Compensational patterns of speech sound processing may be activated in syllable detection, but may not be functional in more complex tasks. The degree to which compensational processes can be activated probably varies depending on factors as lesion site, time after injury, and

  15. Cue Reactivity Essentials: Event-Related Potentials During Identification of Visual Alcoholic Stimuli in Social Drinkers.

    Science.gov (United States)

    Kroczek, Agnes M; Haeussinger, Florian B; Hudak, Justin; Vanes, Lucy D; Fallgatter, Andreas J; Ehlis, Ann-Christine

    2018-01-01

    Cue reactivity is an automatic reaction to alcohol-related cues, contributing to the maintenance of drinking behavior and relapse in alcohol dependency. The identification of valid cue-reactivity features is a prerequisite for its clinical application. We were interested in the effects of visual features of alcohol cues (e.g., color) on cue reactivity. Assuming its development at a pre-pathological stage, we analyzed cue reactivity in heavy social drinkers, with light social drinkers as controls. We investigated whether cue reactivity was independent of visual features at an attentional (P100) and a motivational level (late positive potential, LPP). Event-related potentials (ERPs; P100, LPP) were analyzed during a visual beverage classification task in heavy social drinkers and light social drinkers (N = 34 university students). Photographs of beverages were classified as alcoholic or nonalcoholic. Two additional stimulus sets depicted unrecognizable scrambled visual information and recognizable black silhouettes of the original beverages. Analysis of contrast waves inferred content (unrecognized scrambled trials subtracted from original) and color information (recognized shape trials subtracted from original) during visual processing. Linear regression was used to predict Alcohol Use Disorders Identification Test (AUDIT) scores from ERPs. In heavy social drinkers, alcoholic-content LPP was increased and P100 latency was shorter compared with nonalcoholic cues. Linear regression for alcohol content condition in the overall sample revealed shorter P100 latency and increased LPP amplitude predicting AUDIT scores. None of those effects were significant in the visual-feature control condition. Alcohol cue reactivity in heavy social drinkers was related to faster early attentional processes and motivational salience. The effect occurred independently of visual features in the pictures.

  16. Examining Event-Related Potential (ERP correlates of decision bias in recognition memory judgments.

    Directory of Open Access Journals (Sweden)

    Holger Hill

    Full Text Available Memory judgments can be based on accurate memory information or on decision bias (the tendency to report that an event is part of episodic memory when one is in fact unsure. Event related potentials (ERP correlates are important research tools for elucidating the dynamics underlying memory judgments but so far have been established only for investigations of accurate old/new discrimination. To identify the ERP correlates of bias, and observe how these interact with ERP correlates of memory, we conducted three experiments that manipulated decision bias within participants via instructions during recognition memory tests while their ERPs were recorded. In Experiment 1, the bias manipulation was performed between blocks of trials (automatized bias and compared to trial-by-trial shifts of bias in accord with an external cue (flexibly controlled bias. In Experiment 2, the bias manipulation was performed at two different levels of accurate old/new discrimination as the memory strength of old (studied items was varied. In Experiment 3, the bias manipulation was added to another, bottom-up driven manipulation of bias induced via familiarity. In the first two Experiments, and in the low familiarity condition of Experiment 3, we found evidence of an early frontocentral ERP component at 320 ms poststimulus (the FN320 that was sensitive to the manipulation of bias via instruction, with more negative amplitudes indexing more liberal bias. By contrast, later during the trial (500-700 ms poststimulus, bias effects interacted with old/new effects across all three experiments. Results suggest that the decision criterion is typically activated early during recognition memory trials, and is integrated with retrieved memory signals and task-specific processing demands later during the trial. More generally, the findings demonstrate how ERPs can help to specify the dynamics of recognition memory processes under top-down and bottom-up controlled retrieval conditions.

  17. Examining Event-Related Potential (ERP) Correlates of Decision Bias in Recognition Memory Judgments

    Science.gov (United States)

    Hill, Holger; Windmann, Sabine

    2014-01-01

    Memory judgments can be based on accurate memory information or on decision bias (the tendency to report that an event is part of episodic memory when one is in fact unsure). Event related potentials (ERP) correlates are important research tools for elucidating the dynamics underlying memory judgments but so far have been established only for investigations of accurate old/new discrimination. To identify the ERP correlates of bias, and observe how these interact with ERP correlates of memory, we conducted three experiments that manipulated decision bias within participants via instructions during recognition memory tests while their ERPs were recorded. In Experiment 1, the bias manipulation was performed between blocks of trials (automatized bias) and compared to trial-by-trial shifts of bias in accord with an external cue (flexibly controlled bias). In Experiment 2, the bias manipulation was performed at two different levels of accurate old/new discrimination as the memory strength of old (studied) items was varied. In Experiment 3, the bias manipulation was added to another, bottom-up driven manipulation of bias induced via familiarity. In the first two Experiments, and in the low familiarity condition of Experiment 3, we found evidence of an early frontocentral ERP component at 320 ms poststimulus (the FN320) that was sensitive to the manipulation of bias via instruction, with more negative amplitudes indexing more liberal bias. By contrast, later during the trial (500–700 ms poststimulus), bias effects interacted with old/new effects across all three experiments. Results suggest that the decision criterion is typically activated early during recognition memory trials, and is integrated with retrieved memory signals and task-specific processing demands later during the trial. More generally, the findings demonstrate how ERPs can help to specify the dynamics of recognition memory processes under top-down and bottom-up controlled retrieval conditions. PMID

  18. Error processing and response inhibition in excessive computer game players: an event-related potential study.

    Science.gov (United States)

    Littel, Marianne; van den Berg, Ivo; Luijten, Maartje; van Rooij, Antonius J; Keemink, Lianne; Franken, Ingmar H A

    2012-09-01

    Excessive computer gaming has recently been proposed as a possible pathological illness. However, research on this topic is still in its infancy and underlying neurobiological mechanisms have not yet been identified. The determination of underlying mechanisms of excessive gaming might be useful for the identification of those at risk, a better understanding of the behavior and the development of interventions. Excessive gaming has been often compared with pathological gambling and substance use disorder. Both disorders are characterized by high levels of impulsivity, which incorporates deficits in error processing and response inhibition. The present study aimed to investigate error processing and response inhibition in excessive gamers and controls using a Go/NoGo paradigm combined with event-related potential recordings. Results indicated that excessive gamers show reduced error-related negativity amplitudes in response to incorrect trials relative to correct trials, implying poor error processing in this population. Furthermore, excessive gamers display higher levels of self-reported impulsivity as well as more impulsive responding as reflected by less behavioral inhibition on the Go/NoGo task. The present study indicates that excessive gaming partly parallels impulse control and substance use disorders regarding impulsivity measured on the self-reported, behavioral and electrophysiological level. Although the present study does not allow drawing firm conclusions on causality, it might be that trait impulsivity, poor error processing and diminished behavioral response inhibition underlie the excessive gaming patterns observed in certain individuals. They might be less sensitive to negative consequences of gaming and therefore continue their behavior despite adverse consequences. © 2012 The Authors, Addiction Biology © 2012 Society for the Study of Addiction.

  19. Distinct modulation of event-related potentials during motor preparation in patients with motor conversion disorder.

    Directory of Open Access Journals (Sweden)

    Rebekah L Blakemore

    Full Text Available OBJECTIVE: Conversion paresis patients and healthy people feigning weakness both exhibit weak voluntary movement without detectable neuropathology. Uniquely, conversion patients lack a sense of conscious awareness of the origin of their impairment. We investigated whether conversion paresis patients show distinct electroencephalographic (EEG markers associated with their unconscious movement deficits. METHODS: Six unilateral upper limb conversion paresis patients, 12 feigning participants asked to mimic weakness and 12 control participants performed a precued reaction time task, requiring movements of either hand, depending on precue information. Performance measures (force, reaction and movement time, and event-related EEG potentials (ERP were compared, between groups and across hands or hemisphere, using linear mixed models. RESULTS: Feigners generated the same inter-hand difference in reaction and movement time as expressed by patients, even though no specific targets were set nor feedback given on these measures. We found novel ERP signatures specific to patients. When the symptomatic hand was precued, the P3 ERP component accompanying the precue was dramatically larger in patients than in feigning participants. Additionally, in patients the earlier N1 ERP component was diminished when the precue signalled either the symptomatic or asymptomatic hand. CONCLUSIONS: These results are consistent with previous suggestions that lack of awareness of the origin of their symptoms in conversion disorder patients may result from suppression of brain activity normally related to self-agency. In patients the diminished N1 to all precues is consistent with a generalised reduction in cognitive processing of movement-related precues. The P3 enhancement in patients is unlikely to simply reflect changes required for generation of impaired movements, because it was not seen in feigners showing the same behavioural deficits. Rather, this P3 enhancement in

  20. Auditory stream segregation using bandpass noises: evidence from event-related potentials

    Directory of Open Access Journals (Sweden)

    Yingjiu eNie

    2014-09-01

    Full Text Available The current study measured neural responses to investigate auditory stream segregation of noise stimuli with or without clear spectral contrast. Sequences of alternating A and B noise bursts were presented to elicit stream segregation in normal-hearing listeners. The successive B bursts in each sequence maintained an equal amount of temporal separation with manipulations introduced on the last stimulus. The last B burst was either delayed for 50% of the sequences or not delayed for the other 50%. The A bursts were jittered in between every two adjacent B bursts. To study the effects of spectral separation on streaming, the A and B bursts were further manipulated by using either bandpass-filtered noises widely spaced in center frequency or broadband noises. Event-related potentials (ERPs to the last B bursts were analyzed to compare the neural responses to the delay vs. no-delay trials in both passive and attentive listening conditions. In the passive listening condition, a trend for a possible late mismatch negativity (MMN or late discriminative negativity (LDN response was observed only when the A and B bursts were spectrally separate, suggesting that spectral separation in the A and B burst sequences could be conducive to stream segregation at the pre-attentive level. In the attentive condition, a P300 response was consistently elicited regardless of whether there was spectral separation between the A and B bursts, indicating the facilitative role of voluntary attention in stream segregation. The results suggest that reliable ERP measures can be used as indirect indicators for auditory stream segregation in conditions of weak spectral contrast. These findings have important implications for cochlear implant (CI studies – as spectral information available through a CI device or simulation is substantially degraded, it may require more attention to achieve stream segregation.

  1. Cognitive deficits following exposure to pneumococcal meningitis: an event-related potential study

    Directory of Open Access Journals (Sweden)

    Kihara Michael

    2012-03-01

    Full Text Available Abstract Background Pneumococcal meningitis (PM is a severe and life-threatening disease that is associated with cognitive impairment including learning difficulties, cognitive slowness, short-term memory deficits and poor academic performance. There are limited data on cognitive outcomes following exposure to PM from Africa mainly due to lack of culturally appropriate tools. We report cognitive processes of exposed children as measured by auditory and visual event-related potentials. Methods Sixty-five children (32 male, mean 8.4 years, SD 3.0 years aged between 4-15 years with a history of PM and an age-matched control group of 93 children (46 male; mean 8.4 years, SD 2.7 years were recruited from a well-demarcated study area in Kilifi. In the present study, both baseline to peak and peak-to-peak amplitude differences are reported. Results Children with a history of pneumococcal meningitis had significantly longer auditory P1 and P3a latencies and smaller P1 amplitudes compared to unexposed children. In the visual paradigm, children with PM seemingly lacked a novelty P3a component around 350 ms where control children had a maximum, and showed a lack of stimulus differentiation at Nc. Further, children with exposure to PM had smaller peak to peak amplitude (N2-P1 compared to unexposed children. Conclusion The results suggest that children with a history of PM process novelty differently than do unexposed children, with slower latencies and reduced or absent components. This pattern suggests poorer auditory attention and/or cognitive slowness and poorer visual attention orienting, possibly due to disruption in the functions of the lateral prefrontal and superior temporal cortices. ERPs may be useful for assessment of the development of perceptual-cognitive functions in post brain-injury in African children by providing an alternate way of assessing cognitive development in patient groups for whom more typical standardized neuropsychological

  2. Feature extraction of event-related potentials using wavelets: an application to human performance monitoring

    Science.gov (United States)

    Trejo, L. J.; Shensa, M. J.

    1999-01-01

    This report describes the development and evaluation of mathematical models for predicting human performance from discrete wavelet transforms (DWT) of event-related potentials (ERP) elicited by task-relevant stimuli. The DWT was compared to principal components analysis (PCA) for representation of ERPs in linear regression and neural network models developed to predict a composite measure of human signal detection performance. Linear regression models based on coefficients of the decimated DWT predicted signal detection performance with half as many free parameters as comparable models based on PCA scores. In addition, the DWT-based models were more resistant to model degradation due to over-fitting than PCA-based models. Feed-forward neural networks were trained using the backpropagation algorithm to predict signal detection performance based on raw ERPs, PCA scores, or high-power coefficients of the DWT. Neural networks based on high-power DWT coefficients trained with fewer iterations, generalized to new data better, and were more resistant to overfitting than networks based on raw ERPs. Networks based on PCA scores did not generalize to new data as well as either the DWT network or the raw ERP network. The results show that wavelet expansions represent the ERP efficiently and extract behaviorally important features for use in linear regression or neural network models of human performance. The efficiency of the DWT is discussed in terms of its decorrelation and energy compaction properties. In addition, the DWT models provided evidence that a pattern of low-frequency activity (1 to 3.5 Hz) occurring at specific times and scalp locations is a reliable correlate of human signal detection performance. Copyright 1999 Academic Press.

  3. Double dissociation between rules and memory in music: an event-related potential study.

    Science.gov (United States)

    Miranda, Robbin A; Ullman, Michael T

    2007-11-01

    Language and music share a number of characteristics. Crucially, both domains depend on both rules and memorized representations. Double dissociations between the neurocognition of rule-governed and memory-based knowledge have been found in language but not music. Here, the neural bases of both of these aspects of music were examined with an event-related potential (ERP) study of note violations in melodies. Rule-only violations consisted of out-of-key deviant notes that violated tonal harmony rules in novel (unfamiliar) melodies. Memory-only violations consisted of in-key deviant notes in familiar well-known melodies; these notes followed musical rules but deviated from the actual melodies. Finally, out-of-key notes in familiar well-known melodies constituted violations of both rules and memory. All three conditions were presented, within-subjects, to healthy young adults, half musicians and half non-musicians. The results revealed a double dissociation, independent of musical training, between rules and memory: both rule violation conditions, but not the memory-only violations, elicited an early, somewhat right-lateralized anterior-central negativity (ERAN), consistent with previous studies of rule violations in music, and analogous to the early left-lateralized anterior negativities elicited by rule violations in language. In contrast, both memory violation conditions, but not the rule-only violation, elicited a posterior negativity that might be characterized as an N400, an ERP component that depends, at least in part, on the processing of representations stored in long-term memory, both in language and in other domains. The results suggest that the neurocognitive rule/memory dissociation extends from language to music, further strengthening the similarities between the two domains.

  4. Event-related potentials during forced awakening: a tool for the study of acute sleep inertia.

    Science.gov (United States)

    Bastuji, Hélène; Perrin, Fabien; Garcia-Larrea, Luis

    2003-09-01

    Sleep propensity and sleep inertia were assessed in 43 patients with excessive daytime sleepiness (EDS) and 21 sleep-deprived controls, using a forced awakening test under continuous electroencephalographic (EEG) recording. Event-related potentials (ERPs) were first obtained in waking, while participants performed a target detection auditory task. Subjects were then allowed to take a nap with lights off and sleep latency was calculated. After 3 min of continuous sleep, frequent and rare tones were suddenly presented again (and ERPs recorded) in a forced awakening condition, which was repeated a second time if patients fell asleep. ERPs in pre-nap wakefulness did not differ in patients and controls. On forced awakening, almost half (48%) of EDS patients retained morphologically normal ERPs, but showed a significant delay of P300 relative to waking. In the other half of the patients (and none of the controls), the N200/P300 complex to targets was replaced on forced awakening by high-amplitude negative waves ('sleep negativities'). Single subject analysis showed that 65% of patients had abnormal responses during forced awakening (significant P3 delay or sleep negativities), while only three of them (7%) had abnormal ERPs on wakefulness. The presence of sleep negativities was associated with shorter sleep latencies and increased target detection errors on forced awakening. Sleep negativities were more prevalent in narcolepsy and idiopathic hypersomnia than in EDS associated to psychiatric disorders. By combining sleep latency and ERP measures, the forced awakening test provided a robust and relatively rapid tool (45-60 min) to evaluate both sleep propensity and sleep inertia within a single recording session. The test allows each subject to act as his/her own control, thus increasing sensitivity. In the present series, it proved to be much more discriminative than waking ERPs alone to demonstrate specific abnormalities in patients complaining of excessive daytime

  5. Statistical analysis of event-related potential elicited by verb-complement merge in Brazilian Portuguese

    Directory of Open Access Journals (Sweden)

    M. Cagy

    2006-11-01

    Full Text Available An interesting fact about language cognition is that stimulation involving incongruence in the merge operation between verb and complement has often been related to a negative event-related potential (ERP of augmented amplitude and latency of ca. 400 ms - the N400. Using an automatic ERP latency and amplitude estimator to facilitate the recognition of waves with a low signal-to-noise ratio, the objective of the present study was to study the N400 statistically in 24 volunteers. Stimulation consisted of 80 experimental sentences (40 congruous and 40 incongruous, generated in Brazilian Portuguese, involving two distinct local verb-argument combinations (nominal object and pronominal object series. For each volunteer, the EEG was simultaneously acquired at 20 derivations, topographically localized according to the 10-20 International System. A computerized routine for automatic N400-peak marking (based on the ascendant zero-cross of the first waveform derivative was applied to the estimated individual ERP waveform for congruous and incongruous sentences in both series for all ERP topographic derivations. Peak-to-peak N400 amplitude was significantly augmented (P < 0.05; one-sided Wilcoxon signed-rank test due to incongruence in derivations F3, T3, C3, Cz, T5, P3, Pz, and P4 for nominal object series and in P3, Pz and P4 for pronominal object series. The results also indicated high inter-individual variability in ERP waveforms, suggesting that the usual procedure of grand averaging might not be considered a generally adequate approach. Hence, signal processing statistical techniques should be applied in neurolinguistic ERP studies allowing waveform analysis with low signal-to-noise ratio.

  6. Natural speech comprehension in bipolar disorders: an event-related brain potential study among manic patients.

    Science.gov (United States)

    Cermolacce, Michel; Faugère, Mélanie; Micoulaud-Franchi, Jean-Arthur; Belzeaux, Raoul; Maurel, Muriel; Naudin, Jean; Azorin, Jean-Michel; Vion-Dury, Jean

    2014-04-01

    Thought and language disturbances are crucial clinical features in Bipolar Disorders (BD), and constitute a fundamental basis for social cognition. In BD, clinical manifestations such as disorganization and formal thought disorders may play a role in communication disturbances. However, only few studies have explored language disturbances in BD at a neurophysiological level. Two main Event-Related brain Potentials (ERPs) have been used in language comprehension research: the N400 component, elicited by incongruous word with the preceding semantic context, and the Late Positive Component (LPC), associated with non-specifically semantic and more general cognitive processes. Previous studies provided contradictory results regarding N400 in mood disorders, showing either preserved N400 in depression or dysthymia, or altered N400 in BD during semantic priming paradigm. The aim of our study was to explore N400 and LPC among patients with BD in natural speech conditions. ERPs from 19 bipolar type I patients with manic or hypomanic symptomatology and 19 healthy controls were recorded. Participants were asked to listen to congruous and incongruous complete sentences and to judge the match between the final word and the sentence context. Behavioral results and ERPs data were analyzed. At the behavioral level, patients with BD show worst performances than healthy participants. At the electrophysiological level, our results show preserved N400 component in BD. LPC elicited under natural speech conditions shows preserved amplitude but delayed latency in difference waves. Small size of samples, absence of schizophrenic group and medication status. In contrast with the only previous N400 study in BD that uses written semantic priming, our results show a preserved N400 component in ecological and natural speech conditions among patients with BD. Possible implications in terms of clinical specificity are discussed. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. A study of event related potential frequency domain coherency using multichannel electroencephalogram subspace analysis.

    Science.gov (United States)

    Razavipour, Fatemeh; Sameni, Reza

    2015-07-15

    Event related potentials (ERP) are time-locked electrical activities of the brain in direct response to a specific sensory, cognitive, or motor stimulus. ERP components, such as the P300 wave, which are involved in the process of decision-making, help scientists diagnose specific cognitive disabilities. In this study, we utilize the angles between multichannel electroencephalogram (EEG) subspaces in different frequency bands, as a similarity factor for studying the spatial coherency between ERP frequency responses. A matched filter is used to enhance the ERP from background EEG. While previous researches have focused on frequencies below 10 Hz, as the major frequency band of ERP, it is shown that by using the proposed method, significant ERP-related information can also be found in the 25-40 Hz band. These frequency bands are selected by calculating the correlation coefficient between P300 response segments and synthetic EEG, and ERP segments without P300 waves, and by rejecting the bands having the most association with background EEG and non-P300 components. The significance of the results is assessed by real EEG acquired in brain computer interface experiments versus synthetic EEG produced by existing methods in the literature, to assure that the results are not systematic side effects of the proposed framework. The overall results show that the equivalent dipoles corresponding to narrow-band events in the brain are spatially coherent within different (not necessarily adjacent) frequency bands. The results of this study can lead into novel perspectives in ERP studies. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Temporal characteristics of online syntactic sentence planning: an event-related potential study.

    Directory of Open Access Journals (Sweden)

    Inge Timmers

    Full Text Available During sentence production, linguistic information (semantics, syntax, phonology of words is retrieved and assembled into a meaningful utterance. There is still debate on how we assemble single words into more complex syntactic structures such as noun phrases or sentences. In the present study, event-related potentials (ERPs were used to investigate the time course of syntactic planning. Thirty-three volunteers described visually animated scenes using naming formats varying in syntactic complexity: from simple words ('W', e.g., "triangle", "red", "square", "green", "to fly towards", to noun phrases ('NP', e.g., "the red triangle", "the green square", "to fly towards", to a sentence ('S', e.g., "The red triangle flies towards the green square.". Behaviourally, we observed an increase in errors and corrections with increasing syntactic complexity, indicating a successful experimental manipulation. In the ERPs following scene onset, syntactic complexity variations were found in a P300-like component ('S'/'NP'>'W' and a fronto-central negativity (linear increase with syntactic complexity. In addition, the scene could display two actions - unpredictable for the participant, as the disambiguation occurred only later in the animation. Time-locked to the moment of visual disambiguation of the action and thus the verb, we observed another P300 component ('S'>'NP'/'W'. The data show for the first time evidence of sensitivity to syntactic planning within the P300 time window, time-locked to visual events critical of syntactic planning. We discuss the findings in the light of current syntactic planning views.

  9. Effects of low-frequency repetitive transcranial magnetic stimulation on event-related potential P300

    Science.gov (United States)

    Torii, Tetsuya; Sato, Aya; Iwahashi, Masakuni; Iramina, Keiji

    2012-04-01

    The present study analyzed the effects of repetitive transcranial magnetic stimulation (rTMS) on brain activity. P300 latency of event-related potential (ERP) was used to evaluate the effects of low-frequency and short-term rTMS by stimulating the supramarginal gyrus (SMG), which is considered to be the related area of P300 origin. In addition, the prolonged stimulation effects on P300 latency were analyzed after applying rTMS. A figure-eight coil was used to stimulate left-right SMG, and intensity of magnetic stimulation was 80% of motor threshold. A total of 100 magnetic pulses were applied for rTMS. The effects of stimulus frequency at 0.5 or 1 Hz were determined. Following rTMS, an odd-ball task was performed and P300 latency of ERP was measured. The odd-ball task was performed at 5, 10, and 15 min post-rTMS. ERP was measured prior to magnetic stimulation as a control. Electroencephalograph (EEG) was measured at Fz, Cz, and Pz that were indicated by the international 10-20 electrode system. Results demonstrated that different effects on P300 latency occurred between 0.5-1 Hz rTMS. With 1 Hz low-frequency magnetic stimulation to the left SMG, P300 latency decreased. Compared to the control, the latency time difference was approximately 15 ms at Cz. This decrease continued for approximately 10 min post-rTMS. In contrast, 0.5 Hz rTMS resulted in delayed P300 latency. Compared to the control, the latency time difference was approximately 20 ms at Fz, and this delayed effect continued for approximately 15 min post-rTMS. Results demonstrated that P300 latency varied according to rTMS frequency. Furthermore, the duration of the effect was not similar for stimulus frequency of low-frequency rTMS.

  10. [Quantitative EEG and event-related potentials (P300) in partial epilepsy].

    Science.gov (United States)

    Wang, Zhongjin; Wang, Shuang; Ding, Meiping

    2013-05-01

    Quantitative EEG and event-related potential P300 were used to evaluate impairment of cerebral function in patient with partial epilepsy. W value was calculated (power of EEG δ and θ rhythm divided by power of α and β rhythm ) for the extent of focal cortical dysfunction. The W values in left partial epilepsy group, right partial epilepsy group and control group during interictal period compared. The latency, amplitude and reaction time of P300 potential change were observed in each groups. The W values in F(8), T(4) and T(6) regions in patients with left partial epilepsy (P P300 was 54. 76%, the latency, amplitude and reaction team were significantly different to the control group. The abnormal rate of P300 in left and right partial epilepsy groups were 77. 78% and 37.50%, respectively, and the former is significantly higher than the latter. The amplitudes of P300 in C(z) and P(z) of left partial epilepsy were significantly lower than those of right partial epilepsy and control group (P P300 in C(z) and P(z) of all partial epilepsy were significantly longer than those of control group (P < 0.05), however, no difference was found between left and right partial epilepsy. In partial epilepsy the cortical dysfunction occurs ipsilaterally to the epileptogenic zone, and extent of cortical dysfunction is positively correlated with duration of disease course. Cerebral dysfunction in left partial epilepsy is more severe than that in right partial epilepsy.

  11. Analysis of neural sources of p300 event-related potential in normal and schizophrenic participants.

    Science.gov (United States)

    Sabeti, Malihe; Moradi, Ehsan; Katebi, Serajeddin

    2011-01-01

    The P300 event-related potential (ERP) is associated with attention and memory operations of the brain. P300 is changed in many cognitive disorders such as dementia, Alzheimer, schizophrenia, and major depression disorder. Therefore, investigation on basis of this component can help to improve our understanding of pathophysiology of such disorders and fundamentals of memory and attention mechanism. In this study, electroencephalography (EEG) signals of 20 schizophrenic patients and 20 age-matched normal subjects are analyzed. The oddball paradigm has been used to record the P300, where two stimuli including target and standard are presented with different probabilities in a random order. Data analysis is carried out using conventional averaging techniques as well as P300 source localization with low-resolution brain electromagnetic tomography (LORETA). The results show that the P300 components stem from a wide cerebral cortex network and defining a small definite cortical zone as its generator is impossible. In normal group, cingulate gyrus, one of the essential components of working memory circuit that was reported by Papez, is found to be the most activated area and it can be in line with the hypothesis that at least a part of the P300 is elicited by working-memory circuit. In schizophrenic group, frontal lobe is the most activated area that was responsible for P300 sources. Our results show that the cingulate gyrus is not activated in comparison with normal group, which is in line with previous results that dysfunction of the anterior cingulate cortex plays a prominent role in the schizophrenia disorder.

  12. Fast stimulus sequences improve the efficiency of event-related potential P300 recordings.

    Science.gov (United States)

    Mell, Dominik; Bach, Michael; Heinrich, Sven P

    2008-09-30

    The P300 is an easily recorded component of the event-related potential (ERP). Yet, it is desirable to reduce the recording duration, for instance in patient examinations. A limiting factor is the time between stimuli that is necessary for the ERP to return to baseline. We explored whether this time could be reduced, despite an overlap of responses to successive stimuli, by presenting visual stimuli at a fast rate of 4.7 s(-1)using a standard oddball paradigm. Rare stimuli occurred at a probability of 14%. The P300 was isolated by subtracting the responses to the frequent stimuli from those to the rare stimuli, thereby eliminating the influence of response overlap. We compared the efficiency of fast stimulation to that of conventionally slow stimulation by assessing the signal-to-noise ratio of the P300 amplitude. Two presentation durations of individual stimuli, namely 53 ms and 93 ms, were tested. Not unexpectedly, P300 amplitudes were smaller for the fast sequence. However, the signal-to-noise ratio improved significantly by more than 50% due to the larger number of trials within a given time interval. When targeting a given signal-to-noise ratio, fast stimulation allows for a reduction in recording time of around 35%. Median peak times were 16-56 ms shorter for the fast stimulus sequence. Topography was comparable for fast and slow stimulation, suggesting a similar functional composition of the respective responses. Fast stimulation may thus be used to replace less efficient slow stimulation schemes in clinical diagnosis and for certain experimental questions.

  13. Multivariate evaluation of brain function by measuring regional cerebral blood flow and event-related potentials

    Energy Technology Data Exchange (ETDEWEB)

    Koga, Yoshihiko; Mochida, Masahiko; Shutara, Yoshikazu; Nakagawa, Kazumi [Kyorin Univ., Mitaka, Tokyo (Japan). School of Medicine; Nagata, Ken

    1998-07-01

    To measure the effect of events on human cognitive function, effects of odors by measurement regional cerebral blood flow (rCBF) and P300 were evaluated during the auditory odd-ball exercise. PET showed the increase in rCBF on the right hemisphere of the brain by coffee aroma. rCBF was measured by PET in 9 of right-handed healthy adults men, and P300 was by event-related potential (ERP) in each sex of 20 right-handed healthy adults. ERP showed the difference of the P300 amplitude between men and women, and showed the tendency, by odors except the lavender oil, that women had higher in the P300 amplitude than men. These results suggest the presence of effects on the cognitive function through emotional actions. Next, the relationship between rCBF and ERP were evaluated. The subjects were 9 of the right-handed healthy adults (average: 25.6{+-}3.4 years old). rCBF by PET and P300 amplitude by ERP were simultaneously recorded during the auditory odd-ball exercise using the tone-burst method (2 kHz of the low frequency aimed stimuli and 1 kHz of the high frequency non-aimed stimuli). The rCBF value was the highest at the transverse gyrus of Heschl and the lowest at the piriform cortex among 24 regions of interest (ROI) from both sides. The difference of P300 peak latent time among ROI was almost the same. The brain waves from Cz and Pz were similar and the average amplitude was highest at Pz. We found the high correlation in the right piriform cortex (Fz), and right (Fz, Cz) and left (Cz, Pz) transverse gyrus of Heschl between the P300 amplitude and rCBF. (K.H.)

  14. Regularization and a general linear model for event-related potential estimation.

    Science.gov (United States)

    Kristensen, Emmanuelle; Guerin-Dugué, Anne; Rivet, Bertrand

    2017-12-01

    The usual event-related potential (ERP) estimation is the average across epochs time-locked on stimuli of interest. These stimuli are repeated several times to improve the signal-to-noise ratio (SNR) and only one evoked potential is estimated inside the temporal window of interest. Consequently, the average estimation does not take into account other neural responses within the same epoch that are due to short inter stimuli intervals. These adjacent neural responses may overlap and distort the evoked potential of interest. This overlapping process is a significant issue for the eye fixation-related potential (EFRP) technique in which the epochs are time-locked on the ocular fixations. The inter fixation intervals are not experimentally controlled and can be shorter than the neural response's latency. To begin, the Tikhonov regularization, applied to the classical average estimation, was introduced to improve the SNR for a given number of trials. The generalized cross validation was chosen to obtain the optimal value of the ridge parameter. Then, to deal with the issue of overlapping, the general linear model (GLM), was used to extract all neural responses inside an epoch. Finally, the regularization was also applied to it. The models (the classical average and the GLM with and without regularization) were compared on both simulated data and real datasets from a visual scene exploration in co-registration with an eye-tracker, and from a P300 Speller experiment. The regularization was found to improve the estimation by average for a given number of trials. The GLM was more robust and efficient, its efficiency actually reinforced by the regularization.

  15. Event-Related Potentials of Bottom-Up and Top-Down Processing of Emotional Faces.

    Science.gov (United States)

    Moradi, Afsane; Mehrinejad, Seyed Abolghasem; Ghadiri, Mohammad; Rezaei, Farzin

    2017-01-01

    Emotional stimulus is processed automatically in a bottom-up way or can be processed voluntarily in a top-down way. Imaging studies have indicated that bottom-up and top-down processing are mediated through different neural systems. However, temporal differentiation of top-down versus bottom-up processing of facial emotional expressions has remained to be clarified. The present study aimed to explore the time course of these processes as indexed by the emotion-specific P100 and late positive potential (LPP) event-related potential (ERP) components in a group of healthy women. Fourteen female students of Alzahra University, Tehran, Iran aged 18-30 years, voluntarily participated in the study. The subjects completed 2 overt and covert emotional tasks during ERP acquisition. The results indicated that fearful expressions significantly produced greater P100 amplitude compared to other expressions. Moreover, the P100 findings showed an interaction between emotion and processing conditions. Further analysis indicated that within the overt condition, fearful expressions elicited more P100 amplitude compared to other emotional expressions. Also, overt conditions created significantly more LPP latencies and amplitudes compared to covert conditions. Based on the results, early perceptual processing of fearful face expressions is enhanced in top-down way compared to bottom-up way. It also suggests that P100 may reflect an attentional bias toward fearful emotions. However, no such differentiation was observed within later processing stages of face expressions, as indexed by the ERP LPP component, in a top-down versus bottom-up way. Overall, this study provides a basis for further exploring of bottom-up and top-down processes underlying emotion and may be typically helpful for investigating the temporal characteristics associated with impaired emotional processing in psychiatric disorders.

  16. A semântica de Eros no tempo patrístico

    Directory of Open Access Journals (Sweden)

    Ulysses Roberto Lio Tropia

    2009-05-01

    Full Text Available O objetivo deste artigo é mostrar a semântica da palavra Eros dentro da tradição cristã. Limita-se a algumas dessas significações. A reflexão mostra a limitação dessa expressão na língua portuguesa. Seu significado é muito mais rico na língua grega. Se a tradição cristã carregou esta palavra de forma negativa, outros Padres leram-na em sintonia com Ágape e com outros significados. A relação mística a interpreta como uma relação “erótica” entre homem e Deus. Esta intimidade procura explicar o aspecto do desejo de Deus e da relação mútua entre aquele que ama e o amado, que tem sua raiz na busca mais íntima da humanidade. Negar por preconceitos palavras carregadas de desejos não divinos e nem dignos da humanidade, como na Antigüidade, é reduzir demais seu campo semântico na história. Esta palavra reflete o amor da alma para com Deus numa perspectiva mística, assume variações significativas, dentre tantas, como o amor de Jesus Cristo, como sinônimas de Ágape, do amor de Deus para com os homens, como amor individual ligado a Deus, o Eros como virtude e como castidade. A compreensão das dimensões do amor se realiza na capacidade de ver que todas elas são positivas e importantes para obtermos o equilíbrio da vida humana, numa harmonia destas dimensões constitutivas e importantes para a vida.Palavras-chave: Eros; Patrística; Amor; Alma; Mística; Virtude; Castidade e Ágape.ABSTRACTThis article aims at demonstrating the semantics of the term Eros in Christian tradition, pointing out the limitations of the term in Portuguese. The scope of its meaning is much wider in Greek. If Christian tradition has charged the word with a negative feature, other priests have read it in tune with Agape and other meanings. The mystical perspective interprets it as an ‘erotic’ relationship between man and God. Such intimacy attempts to explain God’s desire and the mutual relation between the one who loves and the

  17. Microelectronic oscillator, 2

    Science.gov (United States)

    Kleinberg, L. L.

    1969-01-01

    Microelectronic oscillator uses a bipolar transistor to circumvent the problem of developing suitable inductors for lower frequencies. The oscillator is fabricated by hybrid thin film techniques or by monolithic construction. Discrete microminiature components may also be employed.

  18. Oscillating heat pipes

    CERN Document Server

    Ma, Hongbin

    2015-01-01

    This book presents the fundamental fluid flow and heat transfer principles occurring in oscillating heat pipes and also provides updated developments and recent innovations in research and applications of heat pipes. Starting with fundamental presentation of heat pipes, the focus is on oscillating motions and its heat transfer enhancement in a two-phase heat transfer system. The book covers thermodynamic analysis, interfacial phenomenon, thin film evaporation,  theoretical models of oscillating motion and heat transfer of single phase and two-phase flows, primary  factors affecting oscillating motions and heat transfer,  neutron imaging study of oscillating motions in an oscillating heat pipes, and nanofluid’s effect on the heat transfer performance in oscillating heat pipes.  The importance of thermally-excited oscillating motion combined with phase change heat transfer to a wide variety of applications is emphasized. This book is an essential resource and learning tool for senior undergraduate, gradua...

  19. Phenomenology of neutrino oscillations

    Indian Academy of Sciences (India)

    Abstract. The phenomenology of solar, atmospheric, supernova and laboratory neutrino oscillations is described. Analytical formulae for matter effects are reviewed. The results from oscillations are confronted with neutrinoless double beta decay.

  20. The colpitts oscillator family

    DEFF Research Database (Denmark)

    Lindberg, Erik; Murali, K.; Tamasevicius, A.

    A tutorial study of the Colpitts oscillator family defined as all oscillators based on a nonlinear amplifier and a three- terminal linear resonance circuit with one coil and two capacitors. The original patents are investigated. The eigenvalues of the linearized Jacobian for oscillators based...

  1. Auditory event-related potentials as indicators of good prognosis in coma of non-anoxic etiology

    OpenAIRE

    Jabbour, Rosette; Sawaya, Raja A.

    2010-01-01

    The aim of this study is to evaluate whether auditory event-related potentials can predict the prognosis of recovery from coma resulting from different etiologies. The results of this study could then be used as an adjuvant test in helping the clinician evaluate patients in coma. We performed P300 auditory event-related potentials on 21 patients who developed a state of coma at our institution. We compared the results to the Glasgow coma scale at the onset of coma, on day 3, and day 21. We...

  2. Markov Switching Model for Quick Detection of Event Related Desynchronization in EEG

    Directory of Open Access Journals (Sweden)

    Giuseppe Lisi

    2018-02-01

    Full Text Available Quick detection of motor intentions is critical in order to minimize the time required to activate a neuroprosthesis. We propose a Markov Switching Model (MSM to achieve quick detection of an event related desynchronization (ERD elicited by motor imagery (MI and recorded by electroencephalography (EEG. Conventional brain computer interfaces (BCI rely on sliding window classifiers in order to perform online continuous classification of the rest vs. MI classes. Based on this approach, the detection of abrupt changes in the sensorimotor power suffers from an intrinsic delay caused by the necessity of computing an estimate of variance across several tenths of a second. Here we propose to avoid explicitly computing the EEG signal variance, and estimate the ERD state directly from the voltage information, in order to reduce the detection latency. This is achieved by using a model suitable in situations characterized by abrupt changes of state, the MSM. In our implementation, the model takes the form of a Gaussian observation model whose variance is governed by two latent discrete states with Markovian dynamics. Its objective is to estimate the brain state (i.e., rest vs. ERD given the EEG voltage, spatially filtered by common spatial pattern (CSP, as observation. The two variances associated with the two latent states are calibrated using the variance of the CSP projection during rest and MI, respectively. The transition matrix of the latent states is optimized by the “quickest detection” strategy that minimizes a cost function of detection latency and false positive rate. Data collected by a dry EEG system from 50 healthy subjects, was used to assess performance and compare the MSM with several logistic regression classifiers of different sliding window lengths. As a result, the MSM achieves a significantly better tradeoff between latency, false positive and true positive rates. The proposed model could be used to achieve a more reactive and

  3. Neurocognitive impairment of mental rotation in major depressive disorder: evidence from event-related brain potentials.

    Science.gov (United States)

    Chen, Jiu; Ma, Wentao; Zhang, Yan; Yang, Lai-Qi; Zhang, Zhijun; Wu, Xingqu; Deng, Zihe

    2014-08-01

    Mental rotation performance may be used as an index of mental slowing or bradyphrenia and may reflect speed of motor preparation. Previous studies suggest that major depressive disorder (MDD) presents correlates of impaired behavioral performance for mental rotation and psychomotor disturbance. Very little is known about the electrophysiological mechanism underlying this deficit. The present study was the first to investigate the event-related brain potential (ERP) correlates of mental rotation and their mental slowing or bradyphrenia in MDD. ERPs were recorded while we tested 25 MDD patients and 26 healthy controls by evaluating the performance of MDD patients on hand and letter rotation tasks at different orientations, and their 400-to-600-msec time window was measured and analyzed for latencies and peak amplitudes over the electrodes. First, individuals with MDD were slower and made more errors in mentally rotating hands and letters than healthy controls did, and individuals with MDD exhibited a greater difference in response times and errors than controls did between hands and letters. Second, the mean peak amplitude was significantly lower and the mean latency was significantly longer in the 400-to-600-msec time window at the parietal site in the hand tasks in MDD patients than in controls, but this was not seen in the letter task, with only lower mean peak amplitude. MDD patients present the absence of a typical mental rotation function for the amplitude of the rotation-related negativity in the hand and letter tasks. Third, the scalp activity maps in MDD patients exhibited the absence of activation in the left parietal site for the mental rotation of hands, as shown in healthy participants. In contrast, their brain activation for the letter task was similar to those of healthy participants. These data suggest that mental imagery of hands and letters relies on different cognitive and neural mechanisms and indicate that the left posterior parietal lobe is a

  4. Event-related potentials as a measure of sleep disturbance: A tutorial review

    Directory of Open Access Journals (Sweden)

    Kenneth Campbell

    2010-01-01

    Full Text Available This article reviews event-related potentials (ERPs the minute responses of the human brain that are elicited by external auditory stimuli and how the ERPs can be used to measure sleep disturbance. ERPs consist of a series of negative- and positive-going components. A negative component peaking at about 100 ms, N1, is thought to reflect the outcome of a transient detector system, activated by change in the transient energy in an acoustic stimulus. Its output and thus the amplitude of N1 increases as the intensity level of the stimulus is increased and when the rate of presentation is slowed. When the output reaches a certain critical level, operations of the central executive are interrupted and attention is switched to the auditory channel. This switching of attention is thought to be indexed by a later positivity, P3a, peaking between 250 and 300 ms. In order to sleep, consciousness for all but the most relevant of stimuli must be prevented. Thus, during sleep onset and definitive non-rapid eye movement (NREM sleep, the amplitude of N1 diminishes to near-baseline level. The amplitude of P2, peaking from 180 to 200 ms, is however larger in NREM sleep than in wakefulness. P2 is thought to reflect an inhibitory process protecting sleep from irrelevant disturbance. As stimulus input becomes increasingly obtrusive, the amplitude of P2 also increases. With increasing obtrusiveness particularly when stimuli are presented slowly, a later large negativity, peaking at about 350 ms, N350, becomes apparent. N350 is unique to sleep, its amplitude also increasing as the stimulus becomes more obtrusive. Many authors postulate that when the N350 reaches a critical amplitude, a very large amplitude N550, a component of the K-Complex is elicited. The K-Complex can only be elicited during NREM sleep. The P2, N350 and N550 processes are thus conceived as sleep protective mechanisms, activated sequentially as the risk for disturbance increases. During REM sleep

  5. Verbal Learning and Memory in Cannabis and Alcohol Users: An Event-Related Potential Investigation

    Directory of Open Access Journals (Sweden)

    Janette L. Smith

    2017-12-01

    Full Text Available Aims: Long-term heavy use of cannabis and alcohol are known to be associated with memory impairments. In this study, we used event-related potentials to examine verbal learning and memory processing in a commonly used behavioral task.Method: We conducted two studies: first, a small pilot study of adolescent males, comprising 13 Drug-Naive Controls (DNC, 12 heavy drinkers (HD and 8 cannabis users (CU. Second, a larger study of young adults, comprising 45 DNC (20 female, 39 HD (16 female, and 20 CU (9 female. In both studies, participants completed a modified verbal learning task (the Rey Auditory Verbal Learning Test, RAVLT while brain electrical activity was recorded. ERPs were calculated for words which were subsequently remembered vs. those which were not remembered, and for presentations of learnt words, previously seen words, and new words in a subsequent recognition test. Pre-planned principal components analyses (PCA were used to quantify the ERP components in these recall and recognition phases separately for each study.Results: Memory performance overall was slightly lower than published norms using the standardized RAVLT delivery, but was generally similar and showed the expected changes over trials. Few differences in performance were observed between groups; a notable exception was markedly poorer delayed recall in HD relative to DNC (Study 2. PCA identified components expected from prior research using other memory tasks. At encoding, there were no between-group differences in the usual P2 recall effect (larger for recalled than not-recalled words. However, alcohol-related differences were observed in a larger P540 (indexing recollection in HD than DNC, and cannabis-related differences were observed in a smaller N340 (indexing familiarity and a lack of previously seen > new words effect for P540 in Study 2.Conclusions: This study is the first examination of ERPs in the RAVLT in healthy control participants, as well as substance

  6. Hemispheric asymmetry in interpreting novel literal language: an event-related potential study.

    Science.gov (United States)

    Davenport, Tristan; Coulson, Seana

    2013-04-01

    Conceptual mapping, or making connections between conceptual structure in different domains, is a key mechanism of creative language use whose neural underpinnings are not well understood. The present study involved the combination of event-related potentials (ERPs) with the divided visual field presentation technique to explore the relative contributions of the left and right hemispheres (LH and RH) to the construction of novel meanings in fully literal language. Electroencephalogram (EEG) was recorded as healthy adults read sentences that supported either a conventional literal reading of the sentence final word ("His main method of transportation is a boat,"), or a novel literal meaning derived from conceptual mapping ("The clever boys used a cardboard box as a boat,"). The novel and conventional conditions were matched for cloze probability (a measure of predictability based on the sentence context), lexical association between the sentence frame and the final word (using latent semantic analysis), and other factors known to influence ERPs to language stimuli. To compare effects of novelty to previously reported effects of predictability, a high-cloze conventional condition ("The only way to get around Venice is to navigate the canals in a boat.") was included. ERPs were time-locked to sentence final words ("boat") presented in either the left visual field, to preferentially stimulate the RH (lvf/RH), or in the right visual field, targeting the LH (rvf/LH). The N400 component of the ERP was affected by predictability in both presentation sides, but by novelty only in rvf/LH. Two distinct late frontal positive effects were observed. Word predictability modulated a frontal positivity with a LH focus, but semantic novelty modulated a frontal positivity focused in RH. This is the first demonstration that the frontal positivity may be composed of multiple overlapping components with distinct functional and anatomical characteristics. Extending contemporary accounts

  7. Cortical Neural Synchronization Underlies Primary Visual Consciousness of Qualia: Evidence from Event-Related Potentials

    Science.gov (United States)

    Babiloni, Claudio; Marzano, Nicola; Soricelli, Andrea; Cordone, Susanna; Millán-Calenti, José Carlos; Del Percio, Claudio; Buján, Ana

    2016-01-01

    This article reviews three experiments on event-related potentials (ERPs) testing the hypothesis that primary visual consciousness (stimulus self-report) is related to enhanced cortical neural synchronization as a function of stimulus features. ERP peak latency and sources were compared between “seen” trials and “not seen” trials, respectively related and unrelated to the primary visual consciousness. Three salient features of visual stimuli were considered (visuospatial, emotional face expression, and written words). Results showed the typical visual ERP components in both “seen” and “not seen” trials. There was no statistical difference in the ERP peak latencies between the “seen” and “not seen” trials, suggesting a similar timing of the cortical neural synchronization regardless the primary visual consciousness. In contrast, ERP sources showed differences between “seen” and “not seen” trials. For the visuospatial stimuli, the primary consciousness was related to higher activity in dorsal occipital and parietal sources at about 400 ms post-stimulus. For the emotional face expressions, there was greater activity in parietal and frontal sources at about 180 ms post-stimulus. For the written letters, there was higher activity in occipital, parietal and temporal sources at about 230 ms post-stimulus. These results hint that primary visual consciousness is associated with an enhanced cortical neural synchronization having entirely different spatiotemporal characteristics as a function of the features of the visual stimuli and possibly, the relative qualia (i.e., visuospatial, face expression, and words). In this framework, the dorsal visual stream may be synchronized in association with the primary consciousness of visuospatial and emotional face contents. Analogously, both dorsal and ventral visual streams may be synchronized in association with the primary consciousness of linguistic contents. In this line of reasoning, the ensemble

  8. Synthetic event-related potentials: a computational bridge between neurolinguistic models and experiments.

    Science.gov (United States)

    Barrès, Victor; Simons, Arthur; Arbib, Michael

    2013-01-01

    Our previous work developed Synthetic Brain Imaging to link neural and schema network models of cognition and behavior to PET and fMRI studies of brain function. We here extend this approach to Synthetic Event-Related Potentials (Synthetic ERP). Although the method is of general applicability, we focus on ERP correlates of language processing in the human brain. The method has two components: Phase 1: To generate cortical electro-magnetic source activity from neural or schema network models; and Phase 2: To generate known neurolinguistic ERP data (ERP scalp voltage topographies and waveforms) from putative cortical source distributions and activities within a realistic anatomical model of the human brain and head. To illustrate the challenges of Phase 2 of the methodology, spatiotemporal information from Friederici's 2002 model of auditory language comprehension was used to define cortical regions and time courses of activation for implementation within a forward model of ERP data. The cortical regions from the 2002 model were modeled using atlas-based masks overlaid on the MNI high definition single subject cortical mesh. The electromagnetic contribution of each region was modeled using current dipoles whose position and orientation were constrained by the cortical geometry. In linking neural network computation via EEG forward modeling to empirical results in neurolinguistics, we emphasize the need for neural network models to link their architecture to geometrically sound models of the cortical surface, and the need for conceptual models to refine and adopt brain-atlas based approaches to allow precise brain anchoring of their modules. The detailed analysis of Phase 2 sets the stage for a brief introduction to Phase 1 of the program, including the case for a schema-theoretic approach to language production and perception presented in detail elsewhere. Unlike Dynamic Causal Modeling (DCM) and Bojak's mean field model, Synthetic ERP builds on models of networks

  9. Spatial-Temporal Feature Analysis on Single-Trial Event Related Potential for Rapid Face Identification.

    Science.gov (United States)

    Jiang, Lei; Wang, Yun; Cai, Bangyu; Wang, Yueming; Wang, Yiwen

    2017-01-01

    The event-related potential (ERP) is the brain response measured in electroencephalography (EEG), which reflects the process of human cognitive activity. ERP has been introduced into brain computer interfaces (BCIs) to communicate the computer with the subject's intention. Due to the low signal-to-noise ratio of EEG, most ERP studies are based on grand-averaging over many trials. Recently single-trial ERP detection attracts more attention, which enables real time processing tasks as rapid face identification. All the targets needed to be retrieved may appear only once, and there is no knowledge of target label for averaging. More interestingly, how the features contribute temporally and spatially to single-trial ERP detection has not been fully investigated. In this paper, we propose to implement a local-learning-based (LLB) feature extraction method to investigate the importance of spatial-temporal components of ERP in a task of rapid face identification using single-trial detection. Comparing to previous methods, LLB method preserves the nonlinear structure of EEG signal distribution, and analyze the importance of original spatial-temporal components via optimization in feature space. As a data-driven methods, the weighting of the spatial-temporal component does not depend on the ERP detection method. The importance weights are optimized by making the targets more different from non-targets in feature space, and regularization penalty is introduced in optimization for sparse weights. This spatial-temporal feature extraction method is evaluated on the EEG data of 15 participants in performing a face identification task using rapid serial visual presentation paradigm. Comparing with other methods, the proposed spatial-temporal analysis method uses sparser (only 10% of the total) features, and could achieve comparable performance (98%) of single-trial ERP detection as the whole features across different detection methods. The interesting finding is that the N250 is

  10. Cortical Neural Synchronization Underlies Primary Visual Consciousness of Qualia: Evidence from Event-Related Potentials.

    Science.gov (United States)

    Babiloni, Claudio; Marzano, Nicola; Soricelli, Andrea; Cordone, Susanna; Millán-Calenti, José Carlos; Del Percio, Claudio; Buján, Ana

    2016-01-01

    This article reviews three experiments on event-related potentials (ERPs) testing the hypothesis that primary visual consciousness (stimulus self-report) is related to enhanced cortical neural synchronization as a function of stimulus features. ERP peak latency and sources were compared between "seen" trials and "not seen" trials, respectively related and unrelated to the primary visual consciousness. Three salient features of visual stimuli were considered (visuospatial, emotional face expression, and written words). Results showed the typical visual ERP components in both "seen" and "not seen" trials. There was no statistical difference in the ERP peak latencies between the "seen" and "not seen" trials, suggesting a similar timing of the cortical neural synchronization regardless the primary visual consciousness. In contrast, ERP sources showed differences between "seen" and "not seen" trials. For the visuospatial stimuli, the primary consciousness was related to higher activity in dorsal occipital and parietal sources at about 400 ms post-stimulus. For the emotional face expressions, there was greater activity in parietal and frontal sources at about 180 ms post-stimulus. For the written letters, there was higher activity in occipital, parietal and temporal sources at about 230 ms post-stimulus. These results hint that primary visual consciousness is associated with an enhanced cortical neural synchronization having entirely different spatiotemporal characteristics as a function of the features of the visual stimuli and possibly, the relative qualia (i.e., visuospatial, face expression, and words). In this framework, the dorsal visual stream may be synchronized in association with the primary consciousness of visuospatial and emotional face contents. Analogously, both dorsal and ventral visual streams may be synchronized in association with the primary consciousness of linguistic contents. In this line of reasoning, the ensemble of the cortical neural networks

  11. The development of prospective memory (PM across adolescence: An Event-related potential analysis.

    Directory of Open Access Journals (Sweden)

    Candice eBowman

    2015-06-01

    Full Text Available Prospective memory (PM is an important cognitive function vital for day-to-day functioning. Although there has been extensive research into the decline of PM in older adulthood, little is known about its developmental trajectory throughout adolescence, a time of important brain maturation. In the present study, the development of PM was examined in 85 participants across the following groups: 12 to 13-year-olds (n = 19, 14 to 15-year-olds (n = 21, 16 to 17-year-olds (n = 19, and 18 to 19-year-olds (n = 26. A 30-cue (30 minute event-based PM task (with font-colour stimuli as PM cues and a lexical-decision task as the ongoing task was used while recording Event-Related Potentials (ERPs. The well-established neural correlates of PM, the N300 and parietal positivity, were examined across the age groups. In addition, hierarchical multiple regressions were used to examine the unique contribution of executive functioning measures (viz., the Self-Ordered Pointing Task [SOPT], the Stroop task, and Trail Making Test [TMT] on the ERP components of PM (after controlling for age. First, the established components of ERPs associated with prospective remembering (i.e., N300 and parietal positivity were detected for each age group. Second, although there were no significant age- group differences on the amplitude of the N300, the amplitude of the parietal positivity was found to be different between the 12 to 13-year-olds and 18 to 19-year-olds (viz., the 12 to 13-year-olds had the highest amplitude. Third, for the contribution of executive functioning measures on the amplitude of the ERP components of PM, the regression on the N300 was not significant, however, the SOPT beta weights were significant predictors of the amplitude of the parietal positivity. This relationship was found to be specific for the central and right electrode region. These findings are discussed within the context of brain development and executive functioning along with particular task

  12. Usefulness of event-related potentials in the assessment of mild cognitive impairment

    Directory of Open Access Journals (Sweden)

    Tsolaki Magda

    2008-11-01

    Full Text Available Abstract Background The aim of this study was to determine if changes in latencies and amplitudes of the major waves of Auditory Event-Related Potentials (AERP, correlate with memory status of patients with mild cognitive impairment (MCI and conversion to Alzheimer's disease (AD. 91 patients with MCI (mean ± SD age = 66.6 ± 5.4, MMSE score = 27.7 and 30 age-matched healthy control (AMHC subjects (mean ± SD age = 68.9 ± 9.9 were studied. 54 patients were re-examined after an average period of 14(± 5.2 months. During this time period 5 patients converted to AD. Between-group differences in latency and amplitude of the major AERP waves (N200, P300 and Slow Wave were determined. Within each group, correlation coefficients (CC between these characteristics of the different AERP waves were calculated. Finally, for patients, CCs were determined among each AERP wave and their age and MMSE scores. Confirmatory factor analysis (CFA was used to examine the underlying structure of waveforms both in the control and the patient groups. Results Latencies of all major AERP components were prolonged in patients compared to controls. Patients presented with significantly higher N200 amplitudes, but no significant differences were observed in P300 amplitudes. Significant differences between follow-up and baseline measurements were found for P300 latency (p = 0.009, N200 amplitude (p Conclusion Although we were not able to establish significant correlations between latencies and amplitudes of N200, P300 and SW and the patients' performance in MMSE, which is a psychometric test for classifying patients suffering from MCI, our results point out that the disorganization of the AERP waveform in MCI patients is a potential basis upon which a neurophysiologic methodology for identifying and "staging" MCI can be sought. We also found that delayed N200 latency not only identifies memory changes better than the MMSE, but also may be a potential predictor of the MCI

  13. Event-related potentials to task-irrelevant changes in facial expressions

    Directory of Open Access Journals (Sweden)

    Astikainen Piia

    2009-07-01

    Full Text Available Abstract Background Numerous previous experiments have used oddball paradigm to study change detection. This paradigm is applied here to study change detection of facial expressions in a context which demands abstraction of the emotional expression-related facial features among other changing facial features. Methods Event-related potentials (ERPs were recorded in adult humans engaged in a demanding auditory task. In an oddball paradigm, repeated pictures of faces with a neutral expression ('standard', p = .9 were rarely replaced by pictures with a fearful ('fearful deviant', p = .05 or happy ('happy deviant', p = .05 expression. Importantly, facial identities changed from picture to picture. Thus, change detection required abstraction of facial expression from changes in several low-level visual features. Results ERPs to both types of deviants differed from those to standards. At occipital electrode sites, ERPs to deviants were more negative than ERPs to standards at 150–180 ms and 280–320 ms post-stimulus. A positive shift to deviants at fronto-central electrode sites in the analysis window of 130–170 ms post-stimulus was also found. Waveform analysis computed as point-wise comparisons between the amplitudes elicited by standards and deviants revealed that the occipital negativity emerged earlier to happy deviants than to fearful deviants (after 140 ms versus 160 ms post-stimulus, respectively. In turn, the anterior positivity was earlier to fearful deviants than to happy deviants (110 ms versus 120 ms post-stimulus, respectively. Conclusion ERP amplitude differences between emotional and neutral expressions indicated pre-attentive change detection of facial expressions among neutral faces. The posterior negative difference at 150–180 ms latency resembled visual mismatch negativity (vMMN – an index of pre-attentive change detection previously studied only to changes in low-level features in vision. The positive anterior difference in

  14. Spatial attention facilitates selection of illusory objects: evidence from event-related brain potentials.

    Science.gov (United States)

    Martínez, Antígona; Teder-Salejarvi, Wolfgang; Hillyard, Steven A

    2007-03-30

    The relationship between spatial attention and object-based attention has long been debated. On the basis of behavioral evidence it has been hypothesized that these two forms of attention share a common mechanism, such that directing spatial attention to one part of an object facilitates the selection of the entire object. In a previous study (Martinez, A., Teder-Salejarvi, W., Vazquez, M., Molholm, S., Foxe, J.J., Javitt, D.C., Di Russo, F., Worden, M.S., Hillyard, S.A., 2006. "Objects are highlighted by spatial attention." J. Cogn. Neurosci. 18(2): 298-310) we used recordings of event-related potentials (ERPs) during a paradigm modeled after that of Egly et al. (Egly, R., Driver, J., Rafal, D.R., 1994. Shifting visual attention between objects and locations: evidence from normal and parietal lesion subjects. J. Exp. Psychol. Gen. 123(2) 161-77) to investigate this relationship. As reported in numerous studies of spatial attention, we found the typical pattern of enhanced neural activity in visual cortex elicited by attended stimuli. Unattended stimuli belonging to the same object as the attended stimuli elicited a very similar spatiotemporal pattern of enhanced neural activity that was localized to lateral occipital cortex (LOC). This similarity was taken as evidence that spatial- and object-selective attention share, at least in part, a common neural mechanism. In the present study we further investigate this relationship by examining whether this spread of spatial attention within attended objects can be guided by objects defined by illusory contours. Subjects viewed a display consisting of two illusory rectangular objects and directed attention to continuous sequences of stimuli (brief onsets) at one end of one of the objects. Stimuli occurring at irrelevant locations but belonging to the same attended object elicited larger posterior N1 amplitudes than that elicited by unattended objects forming part of a different object. This object-selective N1 enhancement

  15. Temporal dynamics of attention during encoding versus maintenance of working memory: complementary views from event-related potentials and alpha-band oscillations.

    Science.gov (United States)

    Myers, Nicholas E; Walther, Lena; Wallis, George; Stokes, Mark G; Nobre, Anna C

    2015-03-01

    Working memory (WM) is strongly influenced by attention. In visual WM tasks, recall performance can be improved by an attention-guiding cue presented before encoding (precue) or during maintenance (retrocue). Although precues and retrocues recruit a similar frontoparietal control network, the two are likely to exhibit some processing differences, because precues invite anticipation of upcoming information whereas retrocues may guide prioritization, protection, and selection of information already in mind. Here we explored the behavioral and electrophysiological differences between precueing and retrocueing in a new visual WM task designed to permit a direct comparison between cueing conditions. We found marked differences in ERP profiles between the precue and retrocue conditions. In line with precues primarily generating an anticipatory shift of attention toward the location of an upcoming item, we found a robust lateralization in late cue-evoked potentials associated with target anticipation. Retrocues elicited a different pattern of ERPs that was compatible with an early selection mechanism, but not with stimulus anticipation. In contrast to the distinct ERP patterns, alpha-band (8-14 Hz) lateralization was indistinguishable between cue types (reflecting, in both conditions, the location of the cued item). We speculate that, whereas alpha-band lateralization after a precue is likely to enable anticipatory attention, lateralization after a retrocue may instead enable the controlled spatiotopic access to recently encoded visual information.

  16. ERO modeling and sensitivity analysis of locally enhanced beryllium erosion by magnetically connected antennas

    Science.gov (United States)

    Lasa, A.; Borodin, D.; Canik, J. M.; Klepper, C. C.; Groth, M.; Kirschner, A.; Airila, M. I.; Borodkina, I.; Ding, R.; Contributors, JET

    2018-01-01

    Experiments at JET showed locally enhanced, asymmetric beryllium (Be) erosion at outer wall limiters when magnetically connected ICRH antennas were in operation. A first modeling effort using the 3D erosion and scrape-off layer impurity transport modeling code ERO reproduced qualitatively the experimental outcome. However, local plasma parameters—in particular when 3D distributions are of interest—can be difficult to determine from available diagnostics and so erosion / impurity transport modeling input relies on output from other codes and simplified models, increasing uncertainties in the outcome. In the present contribution, we introduce and evaluate the impact of improved models and parameters with largest uncertainties of processes that impact impurity production and transport across the scrape-off layer, when simulated in ERO: (i) the magnetic geometry has been revised, for affecting the separatrix position (located 50–60 mm away from limiter surface) and thus the background plasma profiles; (ii) connection lengths between components, which lead to shadowing of ion fluxes, are also affected by the magnetic configuration; (iii) anomalous transport of ionized impurities, defined by the perpendicular diffusion coefficient, has been revisited; (iv) erosion yields that account for energy and angular distributions of background plasma ions under the present enhanced sheath potential and oblique magnetic field, have been introduced; (v) the effect of additional erosion sources, such as charge-exchange neutral fluxes, which are dominant in recessed areas like antennas, has been evaluated; (vi) chemically assisted release of Be in molecular form has been included. Sensitivity analysis highlights a qualitative effect (i.e. change in emission patterns) of magnetic shadowing, anomalous diffusion, and inclusion of neutral fluxes and molecular release of Be. The separatrix location, and energy and angular distribution of background plasma fluxes impact erosion

  17. Nature's Autonomous Oscillators

    Science.gov (United States)

    Mayr, H. G.; Yee, J.-H.; Mayr, M.; Schnetzler, R.

    2012-01-01

    Nonlinearity is required to produce autonomous oscillations without external time dependent source, and an example is the pendulum clock. The escapement mechanism of the clock imparts an impulse for each swing direction, which keeps the pendulum oscillating at the resonance frequency. Among nature's observed autonomous oscillators, examples are the quasi-biennial oscillation and bimonthly oscillation of the Earth atmosphere, and the 22-year solar oscillation. The oscillations have been simulated in numerical models without external time dependent source, and in Section 2 we summarize the results. Specifically, we shall discuss the nonlinearities that are involved in generating the oscillations, and the processes that produce the periodicities. In biology, insects have flight muscles, which function autonomously with wing frequencies that far exceed the animals' neural capacity; Stretch-activation of muscle contraction is the mechanism that produces the high frequency oscillation of insect flight, discussed in Section 3. The same mechanism is also invoked to explain the functioning of the cardiac muscle. In Section 4, we present a tutorial review of the cardio-vascular system, heart anatomy, and muscle cell physiology, leading up to Starling's Law of the Heart, which supports our notion that the human heart is also a nonlinear oscillator. In Section 5, we offer a broad perspective of the tenuous links between the fluid dynamical oscillators and the human heart physiology.

  18. The Education of Eros: A History of Education and the Problem of Adolescent Sexuality. Studies in Curriculum Theory Series

    Science.gov (United States)

    Carlson, Dennis L.

    2012-01-01

    "The Education of Eros: is the first and only comprehensive history of sexuality education and the "problem" of adolescent sexuality from the mid-20th century to the beginning of the 21st. It explores how professional health educators, policy makers, and social and religious conservatives differed in their approaches, and battled over what gets…

  19. The thiol oxidant dipyridyl disulfide can supply the PDI-Ero1p pathway with additional oxidative equivalents

    DEFF Research Database (Denmark)

    López-Mirabal, H Reynaldo; Winther, Jakob R

    2007-01-01

    Membrane-permeant oxidants have become a standard tool for studying eukaryotic organisms because they affect the redox state and the redox regulation of different compartments. The ero1-1 mutant is temperature sensitive (37 degrees C) and cannot grow under anaerobic conditions. Low micromolar con...

  20. «Strong as Death is Love»: Eros and Education at the End of Time

    Directory of Open Access Journals (Sweden)

    Samuel D Rocha

    2017-01-01

    Full Text Available This essay is an extended reflection on the relationship between death and love expressed in a fragment from Song of Songs 8:6: «Strong as death is love». The passage will be analyzed through a Jewish, Orthodox, and Catholic exegesis and literary reflection. In particular, the essay describes the role of a particular form of love (eros within a particular form of education (education at the end of time. While eros has frequently been ignored or resigned to a purely sexualized role, we will look closely at Augustine’s eulogy of his mother, Monica, in the Confessions, suggesting that perhaps the most visceral expression of eros is to be found in the phenomenology of death. We will also draw on the phenomenological manifestation of death by looking to the rich description of dying provided by Leo Tolstoy in his novella, The Death of Ivan Ilych. Together these investigations of eros and education yield a «curriculum of death», which draws on the re-conceptualist notion of curriculum. Our claim is that this curriculum of death offers a sense of urgency and seriousness found lacking in schools today, where death abounds, but is rarely if ever addressed in a humanistic way. This final methodological emphasis on the humanities elucidates more directly and critically the role of research for a curriculum of death within the dominance of social science in the field of education.

  1. ERO1-independent production of H2O2 within the endoplasmic reticulum fuels Prdx4-mediated oxidative protein folding.

    Science.gov (United States)

    Konno, Tasuku; Pinho Melo, Eduardo; Lopes, Carlos; Mehmeti, Ilir; Lenzen, Sigurd; Ron, David; Avezov, Edward

    2015-10-26

    The endoplasmic reticulum (ER)-localized peroxiredoxin 4 (PRDX4) supports disulfide bond formation in eukaryotic cells lacking endoplasmic reticulum oxidase 1 (ERO1). The source of peroxide that fuels PRDX4-mediated disulfide bond formation has remained a mystery, because ERO1 is believed to be a major producer of hydrogen peroxide (H2O2) in the ER lumen. We report on a simple kinetic technique to track H2O2 equilibration between cellular compartments, suggesting that the ER is relatively isolated from cytosolic or mitochondrial H2O2 pools. Furthermore, expression of an ER-adapted catalase to degrade lumenal H2O2 attenuated PRDX4-mediated disulfide bond formation in cells lacking ERO1, whereas depletion of H2O2 in the cytosol or mitochondria had no similar effect. ER catalase did not effect the slow residual disulfide bond formation in cells lacking both ERO1 and PRDX4. These observations point to exploitation of a hitherto unrecognized lumenal source of H2O2 by PRDX4 and a parallel slow H2O2-independent pathway for disulfide formation. © 2015 Konno et al.

  2. Age-related changes in involuntary and voluntary attention as reflected in components of the event-related potential (ERP).

    NARCIS (Netherlands)

    Kok, A.

    2000-01-01

    Provides an overview of age-related changes in both involuntary and voluntary attention in adult Ss as manifested in scalp-recorded event related potential (ERP)s. A decline in orienting with old age was inferred from a substantial reduction with age in the magnitude of deviance-related ERP

  3. Selective attention and error processing in an illusory conjunction task - An event-related brain potential study

    NARCIS (Netherlands)

    Wijers, AA; Boksem, MAS

    2005-01-01

    We recorded event-related potentials in an illusory conjunction task, in which subjects were cued on each trial to search for a particular colored letter in a subsequently presented test array, consisting of three different letters in three different colors. In a proportion of trials the target

  4. An event-related brain potential study of visual selective attention to conjunctions of color and shape

    NARCIS (Netherlands)

    Smid, HGOM; Jakob, A; Heinze, HJ

    What cognitive processes underlie event-related brain potential (ERP) effects related to visual multidimensional selective attention and how are these processes organized? We recorded ERPs when participants attended to one conjunction of color, global shape and local shape and ignored other

  5. Selection of independent components representing event-related brain potentials: A data-driven approach for greater objectivity

    NARCIS (Netherlands)

    Wessel, J.R.; Ullsperger, M.

    2011-01-01

    Following the development of increasingly precise measurement instruments and fine-grain analysis tools for electroencephalographic (EEG) data, analysis of single-trial event-related EEG has considerably widened the utility of this non-invasive method to investigate brain activity. Recently,

  6. Differences between human auditory event-related potentials (AERPs) measured at 2 and 4 months after birth

    NARCIS (Netherlands)

    van den Heuvel, Marion I.; Otte, Renee A.; Braeken, Marijke A. K. A.; Winkler, Istvan; Kushnerenko, Elena; Van den Bergh, Bea R. H.

    2015-01-01

    Infant auditory event-related potentials (AERPs) show a series of marked changes during the first year of life. These AERP changes indicate important advances in early development. The current study examined AERP differences between 2- and 4-month-old infants. An auditory oddball paradigm was

  7. Event-Related Potentials Discriminate Familiar and Unusual Goal Outcomes in 5-Month-Olds and Adults

    Science.gov (United States)

    Michel, Christine; Kaduk, Katharina; Ní Choisdealbha, Áine; Reid, Vincent M.

    2017-01-01

    Previous event-related potential (ERP) work has indicated that the neural processing of action sequences develops with age. Although adults and 9-month-olds use a semantic processing system, perceiving actions activates attentional processes in 7-month-olds. However, presenting a sequence of action context, action execution and action conclusion…

  8. Assessing the spatiotemporal evolution of neuronal activation with single-trial event-related potentials and functional MRI

    NARCIS (Netherlands)

    Eichele, T.; Specht, K.; Moosmann, M.; Jongsma, M.L.A.; Quian Quiroga, R.; Nordby, H.; Hugdahl, K.

    2005-01-01

    The brain acts as an integrated information processing system, which methods in cognitive neuroscience have so far depicted in a fragmented fashion. Here, we propose a simple and robust way to integrate functional MRI (fMRI) with single trial event-related potentials (ERP) to provide a more complete

  9. Print-Tuning Lateralization and Handedness : An Event-Related Potential Study in Dyslexic Higher Education Students

    NARCIS (Netherlands)

    van Setten, Ellie R. H.; Martinez-Ferreiro, Silvia; Maurits, Natasha M.; Maassen, Ben A. M.

    Despite their ample reading experience, higher education students with dyslexia still show deficits in reading and reading-related skills. Lateralized print tuning, the early sensitivity to print of the left parietal cortex signalled by the N1 event-related potential (ERP) component, differs between

  10. Attenuated Auditory Event-Related Potentials and Associations with Atypical Sensory Response Patterns in Children with Autism

    Science.gov (United States)

    Donkers, Franc C. L.; Schipul, Sarah E.; Baranek, Grace T.; Cleary, Katherine M.; Willoughby, Michael T.; Evans, Anna M.; Bulluck, John C.; Lovmo, Jeanne E.; Belger, Aysenil

    2015-01-01

    Neurobiological underpinnings of unusual sensory features in individuals with autism are unknown. Event-related potentials elicited by task-irrelevant sounds were used to elucidate neural correlates of auditory processing and associations with three common sensory response patterns (hyperresponsiveness; hyporesponsiveness; sensory seeking).…

  11. Grade-related changes in event-related potentials (ERPs) in primary school children: Differences between two reading tasks.

    NARCIS (Netherlands)

    Licht, R.; Bakker, D.J.; Kok, A.; Bouma, A.

    1992-01-01

    Recorded event-related potentials (ERPs) from the left and right temporal and parietal sites during word reading in 39 boys and 30 girls who were followed over 3 yrs, starting at Grade 1. Task 1 required Ss to read repeatedly presented words; Task 2 consisted of a series of different words, with

  12. Does Silent Reading Speed in Normal Adult Readers Depend on Early Visual Processes? Evidence from Event-Related Brain Potentials

    Science.gov (United States)

    Korinth, Sebastian Peter; Sommer, Werner; Breznitz, Zvia

    2012-01-01

    Little is known about the relationship of reading speed and early visual processes in normal readers. Here we examined the association of the early P1, N170 and late N1 component in visual event-related potentials (ERPs) with silent reading speed and a number of additional cognitive skills in a sample of 52 adult German readers utilizing a Lexical…

  13. Effects of healthy aging on hippocampal and rhinal memory functions: An event-related fMRI study

    NARCIS (Netherlands)

    Daselaar, S.M.; Fleck, M.S.; Dobbins, I.G.; Madden, D.J.; Cabeza, R.

    2006-01-01

    Event-related functional magnetic resonance imaging was used to study the effects of healthy aging on hippocampal and rhinal memory functions. Memory for past events can be based on retrieval accompanied by specific contextual details (recollection) or on the feeling that an event is old or new

  14. Newborn Event-Related Potentials Predict Poorer Pre-Reading Skills in Children at Risk for Dyslexia

    Science.gov (United States)

    Guttorm, Tomi K.; Leppanen, Paavo H. T.; Hamalainen, Jarmo A.; Eklund, Kenneth M.; Lyytinen, Heikki J.

    2010-01-01

    Earlier results from the Jyvaskyla Longitudinal Study of Dyslexia showed that newborn event-related potentials (ERPs) of children with and without familial risk for dyslexia were associated with receptive language and verbal memory skills between 2.5 and 5 years of age. We further examined whether these ERPs (responses to synthetic consonant-vowel…

  15. Event-related potentials to conjunctions of spatial frequency and orientation as a function of stimulus parameters and response requirements.

    NARCIS (Netherlands)

    Kenemans, J.L.; Kok, A.; Smulders, F.T.

    1993-01-01

    Event-related potentials (ERPs) were recorded from 7 male graduate students who were required to push a button in response to a given conjunction of spatial frequency and orientation (target) and to ignore conjunctions sharing with the target only frequency (frequency-relevant), only orientation

  16. Classification of event-related potentials associated with response errors in actors and observers based on autoregressive modeling

    NARCIS (Netherlands)

    Vasios, C.E.; Ventouras, E.M.; Matsopoulos, G.K.; Karanasiou, I.; Asvestas, P.; Uzunoglu, N.K.; Schie, H.T. van; Bruijn, E.R.A. de

    2009-01-01

    Event-Related Potentials (ERPs) provide non-invasive measurements of the electrical activity on the scalp related to the processing of stimuli and preparation of responses by the brain. In this paper an ERP-signal classification method is proposed for discriminating between ERPs of correct and

  17. Processing of visual semantic information to concrete words : temporal dynamics and neural mechanisms indicated by event-related brain potentials

    NARCIS (Netherlands)

    van Schie, Hein T.; Wijers, Albertus A.; Mars, Rogier B.; Benjamins, Jeroen S.; Stowe, Laurie A.

    2005-01-01

    Event-related brain potentials were used to study the retrieval of visual semantic information to concrete words, and to investigate possible structural overlap between visual object working memory and concreteness effects in word processing. Subjects performed an object working memory task that

  18. Processing of visual semantic information to concrete words: temporal dynamics and neural mechanisms indicated by event-related brain potentials

    NARCIS (Netherlands)

    Schie, H.T. van; Wijers, A.A.; Mars, R.B.; Benjamins, J.S.; Stowe, L.A.

    2005-01-01

    Event-related brain potentials were used to study the retrieval of visual semantic information to concrete words, and to investigate possible structural overlap between visual object working memory and concreteness effects in word processing. Subjects performed an object working memory task that

  19. Internal consistency of event-related potentials associated with cognitive control: N2/P3 and ERN/Pe

    NARCIS (Netherlands)

    W.J.R. Rietdijk (Wim); I.H.A. Franken (Ingmar); A.R. Thurik (Roy)

    2014-01-01

    textabstractRecent studies in psychophysiology show an increased attention for examining the reliability of Event-Related Potentials (ERPs), which are measures of cognitive control (e.g., Go/No-Go tasks). An important index of reliability is the internal consistency (e.g., Cronbach's alpha) of a

  20. Effect of Mood States on the Breadth of Spatial Attentional Focus: An Event-Related Potential Study

    Science.gov (United States)

    Moriya, Hiroki; Nittono, Hiroshi

    2011-01-01

    In order to determine the processing stage that is responsible for the effect of mood states on the breadth of attentional focus, we recorded event-related potentials from 18 students who performed a flanker task involving adjacent letters. To induce a specific mood state, positive, neutral, or negative affective pictures were presented repeatedly…