WorldWideScience

Sample records for non-linguistic perceptual processes

  1. Right-hemispheric processing of non-linguistic word features

    DEFF Research Database (Denmark)

    Baumgaertner, Annette; Hartwigsen, Gesa; Roman Siebner, Hartwig

    2013-01-01

    Verbal stimuli often induce right-hemispheric activation in patients with aphasia after left-hemispheric stroke. This right-hemispheric activation is commonly attributed to functional reorganization within the language system. Yet previous evidence suggests that functional activation in right......-hemispheric homologues of classic left-hemispheric language areas may partly be due to processing nonlinguistic perceptual features of verbal stimuli. We used functional MRI (fMRI) to clarify the role of the right hemisphere in the perception of nonlinguistic word features in healthy individuals. Participants made......, the right inferior frontal gyrus (IFG), an area previously suggested to support language recovery after left-hemispheric stroke, displayed modality-independent activation during perceptual processing of word stimuli. Our findings indicate that activation of the right hemisphere during language tasks may...

  2. Linguistic and Non-Linguistic Semantic Processing in Individuals with Autism Spectrum Disorders: An ERP Study

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    Coderre, Emily L.; Chernenok, Mariya; Gordon, Barry; Ledoux, Kerry

    2017-01-01

    Individuals with autism spectrum disorders (ASD) experience difficulties with language, particularly higher-level functions like semantic integration. Yet some studies indicate that semantic processing of non-linguistic stimuli is not impaired, suggesting a language-specific deficit in semantic processing. Using a semantic priming task, we…

  3. Linguistic and Non-Linguistic Semantic Processing in Individuals with Autism Spectrum Disorders: An ERP Study.

    Science.gov (United States)

    Coderre, Emily L; Chernenok, Mariya; Gordon, Barry; Ledoux, Kerry

    2017-01-12

    Individuals with autism spectrum disorders (ASD) experience difficulties with language, particularly higher-level functions like semantic integration. Yet some studies indicate that semantic processing of non-linguistic stimuli is not impaired, suggesting a language-specific deficit in semantic processing. Using a semantic priming task, we compared event-related potentials (ERPs) in response to lexico-semantic processing (written words) and visuo-semantic processing (pictures) in adults with ASD and adults with typical development (TD). The ASD group showed successful lexico-semantic and visuo-semantic processing, indicated by similar N400 effects between groups for word and picture stimuli. However, differences in N400 latency and topography in word conditions suggested different lexico-semantic processing mechanisms: an expectancy-based strategy for the TD group but a controlled post-lexical integration strategy for the ASD group.

  4. Contextual Processing of Abstract Concepts Reveals Neural Representations of Non-Linguistic Semantic Content

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    Wilson-Mendenhall, Christine D.; Simmons, W. Kyle; Martin, Alex; Barsalou, Lawrence W.

    2014-01-01

    Concepts develop for many aspects of experience, including abstract internal states and abstract social activities that do not refer to concrete entities in the world. The current study assessed the hypothesis that, like concrete concepts, distributed neural patterns of relevant, non-linguistic semantic content represent the meanings of abstract concepts. In a novel neuroimaging paradigm, participants processed two abstract concepts (convince, arithmetic) and two concrete concepts (rolling, red) deeply and repeatedly during a concept-scene matching task that grounded each concept in typical contexts. Using a catch trial design, neural activity associated with each concept word was separated from neural activity associated with subsequent visual scenes to assess activations underlying the detailed semantics of each concept. We predicted that brain regions underlying mentalizing and social cognition (e.g., medial prefrontal cortex, superior temporal sulcus) would become active to represent semantic content central to convince, whereas brain regions underlying numerical cognition (e.g., bilateral intraparietal sulcus) would become active to represent semantic content central to arithmetic. The results supported these predictions, suggesting that the meanings of abstract concepts arise from distributed neural systems that represent concept-specific content. PMID:23363408

  5. Dissociating linguistic and non-linguistic gesture processing: electrophysiological evidence from American Sign Language.

    Science.gov (United States)

    Grosvald, Michael; Gutierrez, Eva; Hafer, Sarah; Corina, David

    2012-04-01

    A fundamental advance in our understanding of human language would come from a detailed account of how non-linguistic and linguistic manual actions are differentiated in real time by language users. To explore this issue, we targeted the N400, an ERP component known to be sensitive to semantic context. Deaf signers saw 120 American Sign Language sentences, each consisting of a "frame" (a sentence without the last word; e.g. BOY SLEEP IN HIS) followed by a "last item" belonging to one of four categories: a high-close-probability sign (a "semantically reasonable" completion to the sentence; e.g. BED), a low-close-probability sign (a real sign that is nonetheless a "semantically odd" completion to the sentence; e.g. LEMON), a pseudo-sign (phonologically legal but non-lexical form), or a non-linguistic grooming gesture (e.g. the performer scratching her face). We found significant N400-like responses in the incongruent and pseudo-sign contexts, while the gestures elicited a large positivity.

  6. The Development of Perceptual Grouping Biases in Infancy: A Japanese-English Cross-Linguistic Study

    Science.gov (United States)

    Yoshida, Katherine A.; Iversen, John R.; Patel, Aniruddh D.; Mazuka, Reiko; Nito, Hiromi; Gervain, Judit; Werker, Janet F.

    2010-01-01

    Perceptual grouping has traditionally been thought to be governed by innate, universal principles. However, recent work has found differences in Japanese and English speakers' non-linguistic perceptual grouping, implicating language in non-linguistic perceptual processes (Iversen, Patel, & Ohgushi, 2008). Two experiments test Japanese- and…

  7. Neural network processing of natural language: II. Towards a unified model of corticostriatal function in learning sentence comprehension and non-linguistic sequencing.

    Science.gov (United States)

    Dominey, Peter Ford; Inui, Toshio; Hoen, Michel

    2009-01-01

    A central issue in cognitive neuroscience today concerns how distributed neural networks in the brain that are used in language learning and processing can be involved in non-linguistic cognitive sequence learning. This issue is informed by a wealth of functional neurophysiology studies of sentence comprehension, along with a number of recent studies that examined the brain processes involved in learning non-linguistic sequences, or artificial grammar learning (AGL). The current research attempts to reconcile these data with several current neurophysiologically based models of sentence processing, through the specification of a neural network model whose architecture is constrained by the known cortico-striato-thalamo-cortical (CSTC) neuroanatomy of the human language system. The challenge is to develop simulation models that take into account constraints both from neuranatomical connectivity, and from functional imaging data, and that can actually learn and perform the same kind of language and artificial syntax tasks. In our proposed model, structural cues encoded in a recurrent cortical network in BA47 activate a CSTC circuit to modulate the flow of lexical semantic information from BA45 to an integrated representation of meaning at the sentence level in BA44/6. During language acquisition, corticostriatal plasticity is employed to allow closed class structure to drive thematic role assignment. From the AGL perspective, repetitive internal structure in the AGL strings is encoded in BA47, and activates the CSTC circuit to predict the next element in the sequence. Simulation results from Caplan's [Caplan, D., Baker, C., & Dehaut, F. (1985). Syntactic determinants of sentence comprehension in aphasia. Cognition, 21, 117-175] test of syntactic comprehension, and from Gomez and Schvaneveldts' [Gomez, R. L., & Schvaneveldt, R. W. (1994). What is learned from artificial grammars?. Transfer tests of simple association. Journal of Experimental Psychology: Learning

  8. Perceptual reasoning in adaptive fusion processing

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    Kadar, Ivan

    2002-07-01

    The author previously published a unified perceptual reasoning system framework for adaptive sensor fusion and situation assessment. Ths framework is re-examined to highlight the role of human perceptual reasoning and to establish the relationship between human perceptual reasoning and the Joint Director of Laboratories (JDL) fusion levels. Mappings between the fusion levels and the elements of perceptual reasoning are defined. Methods to populate the knowledge bases associated with each component of the perceptual reasoning system are highlighted. The concept and application of perception, the resultant system architecture and its candidate renditions using distributed interacting software agents (ISA) are discussed. The perceptual reasoning system is shown to be a natural governing mechanism for extracting, associating and fusing information from multiple sources while adaptively controlling the fusion level processes for optimum fusion performance. The unified modular system construct is shown to provide a formal framework to accommodate various implementation alternatives. The application of this architectural concept is illustrated for distributed fusion systems architectures and is sued to illustrate the benefits of the adaptive perceptual reasoning system concept.

  9. Communicative Principle of Teaching Foreign Language at Non-linguistic Specialties of the University

    Directory of Open Access Journals (Sweden)

    Olga A. Andreyeva

    2013-01-01

    Full Text Available The article is concerned with the problem of teaching foreign language at non-linguistic specialties of the university. The authors determine the communicative principle as the main trend of training foreign language at non-linguistic specialties of the university. This principle can be implemented both in the language teaching process and in working out of teaching materials and textbooks

  10. Non-linguistic analysis of call center conversations

    CERN Document Server

    Kopparapu, Sunil Kumar

    2014-01-01

    The book focuses on the part of the audio conversation not related to language such as speaking rate (in terms of number of syllables per unit time) and emotion centric features. This text examines using non-linguistics features to infer information from phone calls to call centers. The author analyzes 'how' the conversation happens and not 'what' the conversation is about by audio signal processing and analysis.

  11. Linguistic and perceptual processing of communicative cues in Asperger Syndrome

    OpenAIRE

    Saalasti, Satu

    2012-01-01

    Asperger Syndrome (AS) belongs to autism spectrum disorders where both verbal and non-verbal communication difficulties are at the core of the impairment. Social communication requires a complex use of affective, linguistic-cognitive and perceptual processes. In the four studies included in the current thesis, some of the linguistic and perceptual factors that are important for face-to-face communication were studied using behavioural methods. In all four studies the results obtained from ind...

  12. Selective target processing: perceptual load or distractor salience?

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    Eltiti, Stacy; Wallace, Denise; Fox, Elaine

    2005-07-01

    Perceptual load theory (Lavie, 1995) states that participants cannot engage in focused attention when shown displays containing a low perceptual load, because attentional resources are not exhausted, whereas in high-load displays attention is always focused, because attentional resources are exhausted. An alternative "salience" hypothesis holds that the salience of distractors and not perceptual load per se determines selective attention. Three experiments were conducted to investigate the influence that target and distractor onsets and offsets have on selective processing in a standard interference task. Perceptual load theory predicts that, regardless of target or distractor presentation (onset or offset), interference from ignored distractors should occur in low-load displays only. In contrast, the salience hypothesis predicts that interference should occur when the distractor appears as an onset and would occur for distractor offsets only when the target was also an offset. Interference may even occur in highload displays if the distractor is more salient. The results supported the salience hypothesis.

  13. Constructing knowledge through perceptual processes in making craft-art

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    Milla Ojala

    2013-10-01

    Full Text Available The focus of the study is on the knowledge that is constructed through perceptual processes during craft making in the context of the Finnish Basic Education in the Arts (BEA system. Craft studies in the BEA are defined as craft-art. The research method used is the grounded theory. The data consists of seven interviews and participant observations. Participants in the study are adolescents who study craft-art in the BEA system in Visual Art School, Aimo in Hämeenlinna. The aim of the article is to present, define and reflect on the concepts, properties and dimensions concerning perceptual processes that are discovered in this stage of the study following grounded theory procedures. The perceptual processes are an essential means of constructing knowledge in craft-art. Consequently, one aim of the study is to discuss how these processes are connected to various types of knowledge. The perceptual processes are described by seven concepts: imitative, anticipative, evaluative, experimental, emotional, temporal and bodily perceptions. They indicate on a conceptual level the characteristic of knowledge constructed through perceptual processes in craft-art. Further, theconcepts have several properties that can vary dimensionally between two qualities. The properties are activity, function and position. The dimensions of the properties vary from active to passive, formal to informal and internal to external. In conclusion, the concepts can describe a large range of incidents in different situations. They also seem to describe well the practice of  craft-art and there are several connections with pre-existing concepts of knowledge.Keywords: Craft, Knowledge, Perceptual process, Basic Education in the Arts, Grounded Theory 

  14. Perceptual reasoning managed situation assessment and adaptive fusion processing

    Science.gov (United States)

    Kadar, Ivan

    2001-08-01

    A unified perceptual reasoning system framework for adaptive sensor fusion and situation assessment is presented. The concept and application of perception, the resultant system architecture and its candidate renditions using knowledge- based systems and associative memory are discussed. The perceptual reasoning system is shown to be a natural governing mechanism for extracting, associating and fusing information from multiple sources while adaptively controlling the Joint Director of Laboratories (JDL) Fusion Model processes for optimum fusion system performance. The unified modular system construct is shown to provide a formal framework to accommodate various implementation alternatives. The application of this architectural concept is illustrated for representative network centric surveillance system architecture. A target identification system using Dempster-Shafer declarations level fusion is used to demonstrate the benefits of the adaptive perceptual reasoning system and the iterative evidential reasoning method.

  15. Lexically-guided perceptual learning in speech processing

    NARCIS (Netherlands)

    Eisner, F.

    2006-01-01

    During listening to spoken language, the perceptual system needs to adapt frequently to changes in talkers, and thus to considerable interindividual variability in the articulation of a given speech sound. This thesis investigated a learning process which allows listeners to use stored lexical repre

  16. Effect Size Matters : The Role of Language Statistics and Perceptual Simulation in Conceptual Processing

    NARCIS (Netherlands)

    Louwerse, M.M.; Hutchinson, S; Tillman, R.N.

    2014-01-01

    The cognitive science literature increasingly demonstrates that perceptual representations are activated during conceptual processing. Such findings suggest that the debate on whether conceptual processing is predominantly symbolic or perceptual has been resolved. However, studies too frequently pro

  17. Caffeine effects on perceptual and motor processes

    NARCIS (Netherlands)

    Lorist, MM; Snel, J

    1997-01-01

    The effects of a single dose of caffeine on specific information processing operations were examined by using a visual selective attention task in which subjects were asked to select between a left and right hand response on the basis of two different target letters. The target was presented on a pr

  18. The perceptual flow of phonetic feature processing

    DEFF Research Database (Denmark)

    Greenberg, Steven; Christiansen, Thomas Ulrich

    2008-01-01

    How does the brain process spoken language? It is our thesis that word intelligibility and consonant identification are insufficient by themselves to model how the speech signal is decoded - a finer-grained approach is required. In this study, listeners identified 11 different Danish consonants s...

  19. Perceptual processing of a complex musical context

    DEFF Research Database (Denmark)

    Quiroga Martinez, David Ricardo; Hansen, Niels Christian; Højlund, Andreas

    The mismatch negativity (MMN) is a brain response elicited by deviants in a series of repetitive sounds. It reflects the perception of change in low-level sound features and reliably measures auditory memory and predictive processes. MMN is a valuable tool for the study of music perception. However......, most designs use simple tone patterns as stimuli, failing to represent the complexity of everyday music. We aim to develop a new MMN paradigm using more real-sounding stimuli. We want to determine how the complexity of the context affects auditory predictions as reflected by the MMN. For this purpose...... about music perception and learning in more realistic sound contexts....

  20. Low level perceptual, not attentional, processes modulate distractor interference in high perceptual Load displays: evidence from neglect/extinction

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    Carmel eMevorach

    2014-01-01

    Full Text Available According to perceptual load theory (Lavie, 2005 distractor interference is determined by the availability of attentional resources. If target processing does not exhaust resources (with low perceptual load distractor processing will take place resulting in interference with a primary task; however when target processing uses-up attentional capacity (with high perceptual load interference can be avoided. An alternative account (Tsal & Benoni, 2010 suggests that perceptual load effects can be based on distractor dilution by the mere presence of additional neutral items in high load displays so that the effect is not driven by the amount of attention resources required for target processing. Here we tested whether patients with unilateral neglect or extinction would show dilution effects from neutral items in their contralesional (neglected/extinguished field, even though these items do not impose increased perceptual load on the target and at the same time attract reduced attentional resources compared to stimuli in the ipsilesional field. Thus, such items do not affect the amount of attention resources available for distractor processing. We found that contralesional neutral elements can eliminate distractor interference as strongly as centrally presented ones in neglect/extinction patients, despite contralesional items being less well attended. The data are consistent with an account in terms of perceptual dilution of distracters rather than available resources for distractor processing. We conclude that distractor dilution can underlie the elimination of distractor interference in visual displays.

  1. Low level perceptual, not attentional, processes modulate distractor interference in high perceptual load displays: evidence from neglect/extinction.

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    Mevorach, Carmel; Tsal, Yehoshua; Humphreys, Glyn W

    2014-01-10

    According to perceptual load theory (Lavie, 2005) distractor interference is determined by the availability of attentional resources. If target processing does not exhaust resources (with low perceptual load) distractor processing will take place resulting in interference with a primary task; however, when target processing uses-up attentional capacity (with high perceptual load) interference can be avoided. An alternative account (Tsal and Benoni, 2010a) suggests that perceptual load effects can be based on distractor dilution by the mere presence of additional neutral items in high-load displays so that the effect is not driven by the amount of attention resources required for target processing. Here we tested whether patients with unilateral neglect or extinction would show dilution effects from neutral items in their contralesional (neglected/extinguished) field, even though these items do not impose increased perceptual load on the target and at the same time attract reduced attentional resources compared to stimuli in the ipsilesional field. Thus, such items do not affect the amount of attention resources available for distractor processing. We found that contralesional neutral elements can eliminate distractor interference as strongly as centrally presented ones in neglect/extinction patients, despite contralesional items being less well attended. The data are consistent with an account in terms of perceptual dilution of distracters rather than available resources for distractor processing. We conclude that distractor dilution can underlie the elimination of distractor interference in visual displays.

  2. Constructing knowledge through perceptual processes in making craft-art

    OpenAIRE

    2013-01-01

    The focus of the study is on the knowledge that is constructed through perceptual processes during craft making in the context of the Finnish Basic Education in the Arts (BEA) system. Craft studies in the BEA are defined as craft-art. The research method used is the grounded theory. The data consists of seven interviews and participant observations. Participants in the study are adolescents who study craft-art in the BEA system in Visual Art School, Aimo in Hämeenlinna. The aim of the article...

  3. Age effects on visual-perceptual processing and confrontation naming.

    Science.gov (United States)

    Gutherie, Audrey H; Seely, Peter W; Beacham, Lauren A; Schuchard, Ronald A; De l'Aune, William A; Moore, Anna Bacon

    2010-03-01

    The impact of age-related changes in visual-perceptual processing on naming ability has not been reported. The present study investigated the effects of 6 levels of spatial frequency and 6 levels of contrast on accuracy and latency to name objects in 14 young and 13 older neurologically normal adults with intact lexical-semantic functioning. Spatial frequency and contrast manipulations were made independently. Consistent with the hypotheses, variations in these two visual parameters impact naming ability in young and older subjects differently. The results from the spatial frequency-manipulations revealed that, in general, young vs. older subjects are faster and more accurate to name. However, this age-related difference is dependent on the spatial frequency on the image; differences were only seen for images presented at low (e.g., 0.25-1 c/deg) or high (e.g., 8-16 c/deg) spatial frequencies. Contrary to predictions, the results from the contrast manipulations revealed that overall older vs. young adults are more accurate to name. Again, however, differences were only seen for images presented at the lower levels of contrast (i.e., 1.25%). Both age groups had shorter latencies on the second exposure of the contrast-manipulated images, but this possible advantage of exposure was not seen for spatial frequency. Category analyses conducted on the data from this study indicate that older vs. young adults exhibit a stronger nonliving-object advantage for naming spatial frequency-manipulated images. Moreover, the findings suggest that bottom-up visual-perceptual variables integrate with top-down category information in different ways. Potential implications on the aging and naming (and recognition) literature are discussed.

  4. Effect of perceptual load on conceptual processing: an extension of Vermeulen's theory.

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    Xie, Jiushu; Wang, Ruiming; Sun, Xun; Chang, Song

    2013-10-01

    The effect of color and shape load on conceptual processing was studied. Perceptual load effects have been found in visual and auditory conceptual processing, supporting the theory of embodied cognition. However, whether different types of visual concepts, such as color and shape, share the same perceptual load effects is unknown. In the current experiment, 32 participants were administered simultaneous perceptual and conceptual tasks to assess the relation between perceptual load and conceptual processing. Keeping color load in mind obstructed color conceptual processing. Hence, perceptual processing and conceptual load shared the same resources, suggesting embodied cognition. Color conceptual processing was not affected by shape pictures, indicating that different types of properties within vision were separate.

  5. Functional communication within a perceptual network processing letters and pseudoletters.

    Science.gov (United States)

    Herdman, Anthony T

    2011-10-01

    Many studies have identified regions within human ventral visual stream to be important for object identification and categorization; however, knowledge of how perceptual information is communicated within the visual network is still limited. Current theories posit that if a high correspondence between incoming sensory information and internal representations exists, then the object is rapidly identified, and if there is not, then the object requires extra detailed processing. Event-related responses from the present magnetoencephalography study showed two main effects. The N1m peak latencies were approximately 15 milliseconds earlier to familiar letters than to unfamiliar pseudoletters, and the N2m was more negative to pseudoletters than to letters. Event-related beamforming analyses identified these effects to be within bilateral visual cortices with a right lateralization for the N2m effect. Furthermore, functional connectivity analyses revealed that gamma-band (50-80 Hz) oscillatory phase synchronizations among occipital regions were greater to letters than to pseudoletters (around 85 milliseconds). However, during a later time interval between 245 and 375 milliseconds, pseudoletters elicited greater gamma-band phase synchronizations among a more distributed occipital network than did letters. These findings indicate that familiar object processing begins by at least 85 milliseconds, which could represent an initial match to an internal template. In addition, unfamiliar object processing persisted longer than that for familiar objects, which could reflect greater attention to inexperienced objects to determine their identity and/or to consolidate a new template to aid in future identification.

  6. Non-Linguistic Vocal Event Detection Using Online Random

    DEFF Research Database (Denmark)

    Abou-Zleikha, Mohamed; Tan, Zheng-Hua; Christensen, Mads Græsbøll

    2014-01-01

    Accurate detection of non-linguistic vocal events in social signals can have a great impact on the applicability of speech enabled interactive systems. In this paper, we investigate the use of random forest for vocal event detection. Random forest technique has been successfully employed in many...... areas such as object detection, face recognition, and audio event detection. This paper proposes to use online random forest technique for detecting laughter and filler and for analyzing the importance of various features for non-linguistic vocal event classification through permutation. The results...... show that according to the Area Under Curve measure the online random forest achieved 88.1% compared to 82.9% obtained by the baseline support vector machines for laughter classification and 86.8% to 83.6% for filler classification....

  7. Interactive educational techniques in teaching a foreign language to non-linguistic students

    Directory of Open Access Journals (Sweden)

    Inna Borisova

    2014-04-01

    Full Text Available The article deals with the concept of interactivity, the opportunities of creating the interactive information space in the educational process. The role of interactive educational techniques in passing from the cognitive paradigm to the competence one is noted. The application of modern information technologies as a means of optimizing the educational process is considered. The author shares her experience of organizing and guiding an interactive foreign language lesson in a group of non-linguistic students. She marks some prospects of further research in the field under study.

  8. Perceptual, Categorical, and Affective Processing of Ambiguous Smiling Facial Expressions

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    Calvo, Manuel G.; Fernandez-Martin, Andres; Nummenmaa, Lauri

    2012-01-01

    Why is a face with a smile but non-happy eyes likely to be interpreted as happy? We used blended expressions in which a smiling mouth was incongruent with the eyes (e.g., angry eyes), as well as genuine expressions with congruent eyes and mouth (e.g., both happy or angry). Tasks involved detection of a smiling mouth (perceptual), categorization of…

  9. The Relationship of Measured Perceptual Processes to School Learning.

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    Kephart, N. C.

    Ten test films were developed to measure aspects of children's visual perception which are difficult to assess through conventional paper and pencil tests. The film medium was selected because it allows the presentation of temporal, as well as spacial, aspects of the stimuli. Four areas of perceptual performance covered in the films are: (1)…

  10. Great Expectations: Temporal Expectation Modulates Perceptual Processing Speed

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    Vangkilde, Signe; Coull, Jennifer T.; Bundesen, Claus

    2012-01-01

    In a crowded dynamic world, temporal expectations guide our attention in time. Prior investigations have consistently demonstrated that temporal expectations speed motor behavior. We explore effects of temporal expectation on "perceptual" speed in three nonspeeded, cued recognition paradigms. Different hazard rate functions for the cue-stimulus…

  11. Prior perceptual processing enhances the effect of emotional arousal on the neural correlates of memory retrieval.

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    Dew, Ilana T Z; Ritchey, Maureen; LaBar, Kevin S; Cabeza, Roberto

    2014-07-01

    A fundamental idea in memory research is that items are more likely to be remembered if encoded with a semantic, rather than perceptual, processing strategy. Interestingly, this effect has been shown to reverse for emotionally arousing materials, such that perceptual processing enhances memory for emotional information or events. The current fMRI study investigated the neural mechanisms of this effect by testing how neural activations during emotional memory retrieval are influenced by the prior encoding strategy. Participants incidentally encoded emotional and neutral pictures under instructions to attend to either semantic or perceptual properties of each picture. Recognition memory was tested 2 days later. fMRI analyses yielded three main findings. First, right amygdalar activity associated with emotional memory strength was enhanced by prior perceptual processing. Second, prior perceptual processing of emotional pictures produced a stronger effect on recollection- than familiarity-related activations in the right amygdala and left hippocampus. Finally, prior perceptual processing enhanced amygdalar connectivity with regions strongly associated with retrieval success, including hippocampal/parahippocampal regions, visual cortex, and ventral parietal cortex. Taken together, the results specify how encoding orientations yield alterations in brain systems that retrieve emotional memories.

  12. The development of emotion recognition from facial expressions and non-linguistic vocalizations during childhood.

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    Chronaki, Georgia; Hadwin, Julie A; Garner, Matthew; Maurage, Pierre; Sonuga-Barke, Edmund J S

    2015-06-01

    Sensitivity to facial and vocal emotion is fundamental to children's social competence. Previous research has focused on children's facial emotion recognition, and few studies have investigated non-linguistic vocal emotion processing in childhood. We compared facial and vocal emotion recognition and processing biases in 4- to 11-year-olds and adults. Eighty-eight 4- to 11-year-olds and 21 adults participated. Participants viewed/listened to faces and voices (angry, happy, and sad) at three intensity levels (50%, 75%, and 100%). Non-linguistic tones were used. For each modality, participants completed an emotion identification task. Accuracy and bias for each emotion and modality were compared across 4- to 5-, 6- to 9- and 10- to 11-year-olds and adults. The results showed that children's emotion recognition improved with age; preschoolers were less accurate than other groups. Facial emotion recognition reached adult levels by 11 years, whereas vocal emotion recognition continued to develop in late childhood. Response bias decreased with age. For both modalities, sadness recognition was delayed across development relative to anger and happiness. The results demonstrate that developmental trajectories of emotion processing differ as a function of emotion type and stimulus modality. In addition, vocal emotion processing showed a more protracted developmental trajectory, compared to facial emotion processing. The results have important implications for programmes aiming to improve children's socio-emotional competence.

  13. Predicting perceptual learning from higher-order cortical processing.

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    Wang, Fang; Huang, Jing; Lv, Yaping; Ma, Xiaoli; Yang, Bin; Wang, Encong; Du, Boqi; Li, Wu; Song, Yan

    2016-01-01

    Visual perceptual learning has been shown to be highly specific to the retinotopic location and attributes of the trained stimulus. Recent psychophysical studies suggest that these specificities, which have been associated with early retinotopic visual cortex, may in fact not be inherent in perceptual learning and could be related to higher-order brain functions. Here we provide direct electrophysiological evidence in support of this proposition. In a series of event-related potential (ERP) experiments, we recorded high-density electroencephalography (EEG) from human adults over the course of learning in a texture discrimination task (TDT). The results consistently showed that the earliest C1 component (68-84ms), known to reflect V1 activity driven by feedforward inputs, was not modulated by learning regardless of whether the behavioral improvement is location specific or not. In contrast, two later posterior ERP components (posterior P1 and P160-350) over the occipital cortex and one anterior ERP component (anterior P160-350) over the prefrontal cortex were progressively modified day by day. Moreover, the change of the anterior component was closely correlated with improved behavioral performance on a daily basis. Consistent with recent psychophysical and imaging observations, our results indicate that perceptual learning can mainly involve changes in higher-level visual cortex as well as in the neural networks responsible for cognitive functions such as attention and decision making.

  14. Enhanced cognitive and perceptual processing: A computational basis for the musician advantage in speech learning

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    Kirsten eSmayda

    2015-05-01

    Full Text Available Long-term music training can positively impact speech processing. A recent framework developed to explain such cross-domain plasticity posits that music training-related advantages in speech processing are due to shared cognitive and perceptual processes between music and speech. Although perceptual and cognitive processing advantages due to music training have been independently demonstrated, to date no study has examined perceptual and cognitive processing within the context of a single task. The present study examines the impact of long-term music training on speech learning from a rigorous, computational perspective derived from signal detection theory. Our computational models provide independent estimates of cognitive and perceptual processing in native English-speaking musicians (n=15, mean age= 25 years and non-musicians (n=15, mean age= 23 years learning to categorize non-native lexical pitch patterns (Mandarin tones. Musicians outperformed non-musicians in this task. Model-based analyses suggested that musicians shifted from simple unidimensional decision strategies to more optimal multidimensional decision strategies sooner than non-musicians. In addition, musicians used optimal decisional strategies more often than non-musicians. However, musicians and non-musicians who used multidimensional strategies showed no difference in performance. We estimated parameters that quantify the magnitude of perceptual variability along two dimensions that are critical for tone categorization: pitch height and pitch direction. Both musicians and non-musicians showed a decrease in perceptual variability along the pitch height dimension, but only musicians showed a significant reduction in perceptual variability along the pitch direction dimension. Notably, these advantages persisted during a generalization phase, when no feedback was provided. These results provide an insight into the mechanisms underlying the musician advantage observed in non

  15. Reflection on College English Vocabulary Teaching from Non-linguistic Context Perspective

    Institute of Scientific and Technical Information of China (English)

    LIU Fang

    2013-01-01

    Vocabulary understanding is very important in English study; however, there exist some problems in the present college English vocabulary teaching, so it is necessary to propose some suggestions for it from the non-linguistic context perspectives to im⁃prove the students’vocabulary capacity. Based on the three non-linguistic contexts (situational context, cultural context and cogni⁃tive context), the passage suggests teachers pay much attention to the non-linguistic context while teaching.

  16. Non-linguistic learning and aphasia: evidence from a paired associate and feedback-based task.

    Science.gov (United States)

    Vallila-Rohter, Sofia; Kiran, Swathi

    2013-01-01

    Though aphasia is primarily characterized by impairments in the comprehension and/or expression of language, research has shown that patients with aphasia also show deficits in cognitive-linguistic domains such as attention, executive function, concept knowledge and memory. Research in aphasia suggests that cognitive impairments can impact the online construction of language, new verbal learning, and transactional success. In our research, we extend this hypothesis to suggest that general cognitive deficits influence progress with therapy. The aim of our study is to explore learning, a cognitive process that is integral to relearning language, yet underexplored in the field of aphasia rehabilitation. We examine non-linguistic category learning in patients with aphasia (n=19) and in healthy controls (n=12), comparing feedback and non-feedback based instruction. Participants complete two computer-based learning tasks that require them to categorize novel animals based on the percentage of features shared with one of two prototypes. As hypothesized, healthy controls showed successful category learning following both methods of instruction. In contrast, only 60% of our patient population demonstrated successful non-linguistic category learning. Patient performance was not predictable by standardized measures of cognitive ability. Results suggest that general learning is affected in aphasia and is a unique, important factor to consider in the field of aphasia rehabilitation. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Experience shapes our odor perception but depends on the initial perceptual processing of the stimulus.

    Science.gov (United States)

    Sinding, Charlotte; Coureaud, Gérard; Bervialle, Boris; Martin, Christophe; Schaal, Benoist; Thomas-Danguin, Thierry

    2015-07-01

    The questions of whether configural and elemental perceptions are competitive or exclusive perceptual processes and whether they rely on independent or dependent mechanisms are poorly understood. To examine these questions, we modified perceptual experience through preexposure to mixed or single odors and measured the resulting variation in the levels of configural and elemental perception of target odor mixtures. We used target mixtures that were spontaneously processed in a configural or an elemental manner. The AB binary mixture spontaneously involved the configural perception of a pineapple odor, whereas component A smelled like strawberry and component B smelled like caramel. The CD mixture produced the elemental perceptions of banana (C) and smoky (D) odors. Perceptual experience was manipulated through repeated exposure to either a mixture (AB or CD) or the components (A and B or C and D). The odor typicality rating data recorded after exposure revealed different influences of experience on odor mixtures and single-component perception, depending both on the type of exposure (components or mixture) and the mixture's initial perceptual property (configural or elemental). Although preexposure to A and B decreased the pineapple typicality of the configural AB mixture, preexposure to AB did not modify its odor quality. In contrast, preexposure to the CD elemental mixture induced a quality transfer between the components. These results emphasize the relative plasticity of odor mixture perception, which is prone to experience-induced modulations but depends on the stimulus's initial perceptual properties, suggesting that configural and elemental forms of odor mixture perception rely on rather independent processes.

  18. Perceptual processing of natural scenes at rapid rates: effects of complexity, content, and emotional arousal.

    Science.gov (United States)

    Löw, Andreas; Bradley, Margaret M; Lang, Peter J

    2013-12-01

    During rapid serial visual presentation (RSVP), the perceptual system is confronted with a rapidly changing array of sensory information demanding resolution. At rapid rates of presentation, previous studies have found an early (e.g., 150-280 ms) negativity over occipital sensors that is enhanced when emotional, as compared with neutral, pictures are viewed, suggesting facilitated perception. In the present study, we explored how picture composition and the presence of people in the image affect perceptual processing of pictures of natural scenes. Using RSVP, pictures that differed in perceptual composition (figure-ground or scenes), content (presence of people or not), and emotional content (emotionally arousing or neutral) were presented in a continuous stream for 330 ms each with no intertrial interval. In both subject and picture analyses, all three variables affected the amplitude of occipital negativity, with the greatest enhancement for figure-ground compositions (as compared with scenes), irrespective of content and emotional arousal, supporting an interpretation that ease of perceptual processing is associated with enhanced occipital negativity. Viewing emotional pictures prompted enhanced negativity only for pictures that depicted people, suggesting that specific features of emotionally arousing images are associated with facilitated perceptual processing, rather than all emotional content.

  19. Between-session intra-individual variability in sustained, selective, and integrational non-linguistic attention in aphasia.

    Science.gov (United States)

    Villard, Sarah; Kiran, Swathi

    2015-01-01

    A number of studies have identified impairments in one or more types/aspects of attention processing in patients with aphasia (PWA) relative to healthy controls; person-to-person variability in performance on attention tasks within the PWA group has also been noted. Studies using non-linguistic stimuli have found evidence that attention is impaired in this population even in the absence of language processing demands. An underlying impairment in non-linguistic, or domain-general, attention processing could have implications for the ability of PWA to attend during therapy sessions, which in turn could impact long-term treatment outcomes. With this in mind, this study aimed to systematically examine the effect of task complexity on reaction time (RT) during a non-linguistic attention task, in both PWA and controls. Additional goals were to assess the effect of task complexity on between-session intra-individual variability (BS-IIV) in RT and to examine inter-individual differences in BS-IIV. Eighteen PWA and five age-matched neurologically healthy controls each completed a novel computerized non-linguistic attention task measuring five types of attention on each of four different non-consecutive days. A significant effect of task complexity on both RT and BS-IIV in RT was found for the PWA group, whereas the control group showed a significant effect of task complexity on RT but not on BS-IIV in RT. Finally, in addition to these group-level findings, it was noted that different patients exhibited different patterns of BS-IIV, indicating the existence of inter-individual variability in BS-IIV within the PWA group. Results may have implications for session-to-session fluctuations in attention during language testing and therapy for PWA.

  20. Neural mechanisms of human perceptual learning: electrophysiological evidence for a two-stage process.

    Science.gov (United States)

    Hamamé, Carlos M; Cosmelli, Diego; Henriquez, Rodrigo; Aboitiz, Francisco

    2011-04-26

    Humans and other animals change the way they perceive the world due to experience. This process has been labeled as perceptual learning, and implies that adult nervous systems can adaptively modify the way in which they process sensory stimulation. However, the mechanisms by which the brain modifies this capacity have not been sufficiently analyzed. We studied the neural mechanisms of human perceptual learning by combining electroencephalographic (EEG) recordings of brain activity and the assessment of psychophysical performance during training in a visual search task. All participants improved their perceptual performance as reflected by an increase in sensitivity (d') and a decrease in reaction time. The EEG signal was acquired throughout the entire experiment revealing amplitude increments, specific and unspecific to the trained stimulus, in event-related potential (ERP) components N2pc and P3 respectively. P3 unspecific modification can be related to context or task-based learning, while N2pc may be reflecting a more specific attentional-related boosting of target detection. Moreover, bell and U-shaped profiles of oscillatory brain activity in gamma (30-60 Hz) and alpha (8-14 Hz) frequency bands may suggest the existence of two phases for learning acquisition, which can be understood as distinctive optimization mechanisms in stimulus processing. We conclude that there are reorganizations in several neural processes that contribute differently to perceptual learning in a visual search task. We propose an integrative model of neural activity reorganization, whereby perceptual learning takes place as a two-stage phenomenon including perceptual, attentional and contextual processes.

  1. Neural mechanisms of human perceptual learning: electrophysiological evidence for a two-stage process.

    Directory of Open Access Journals (Sweden)

    Carlos M Hamamé

    Full Text Available BACKGROUND: Humans and other animals change the way they perceive the world due to experience. This process has been labeled as perceptual learning, and implies that adult nervous systems can adaptively modify the way in which they process sensory stimulation. However, the mechanisms by which the brain modifies this capacity have not been sufficiently analyzed. METHODOLOGY/PRINCIPAL FINDINGS: We studied the neural mechanisms of human perceptual learning by combining electroencephalographic (EEG recordings of brain activity and the assessment of psychophysical performance during training in a visual search task. All participants improved their perceptual performance as reflected by an increase in sensitivity (d' and a decrease in reaction time. The EEG signal was acquired throughout the entire experiment revealing amplitude increments, specific and unspecific to the trained stimulus, in event-related potential (ERP components N2pc and P3 respectively. P3 unspecific modification can be related to context or task-based learning, while N2pc may be reflecting a more specific attentional-related boosting of target detection. Moreover, bell and U-shaped profiles of oscillatory brain activity in gamma (30-60 Hz and alpha (8-14 Hz frequency bands may suggest the existence of two phases for learning acquisition, which can be understood as distinctive optimization mechanisms in stimulus processing. CONCLUSIONS/SIGNIFICANCE: We conclude that there are reorganizations in several neural processes that contribute differently to perceptual learning in a visual search task. We propose an integrative model of neural activity reorganization, whereby perceptual learning takes place as a two-stage phenomenon including perceptual, attentional and contextual processes.

  2. Perceptual chunking and its effect on memory in speech processing: ERP and behavioral evidence.

    Directory of Open Access Journals (Sweden)

    Annie C. Gilbert

    2014-03-01

    Full Text Available We examined how perceptual chunks of varying size in utterances can influence immediate memory of heard items (monosyllabic words. Using behavioral measures and ERPs (N400 we evaluated the quality of the memory trace for targets taken from perceived temporal groups of 3 and 4 items. Variations in the amplitude of the N400 showed a better memory trace for items presented in temporal groups of 3 compared to those in groups of 4. Analyses of behavioral responses along with P300 components also revealed effects of chunk position in the utterance. This is the first study to measure the on-line effects of perceptual chunks on the memory trace of spoken items. Taken together, the N400 and P300 responses demonstrate that the perceptual chunking of speech facilitates information buffering and a processing on a chunk-by-chunk basis.

  3. Habituation and the Response to Discrepancy: Implications for Memory, Retrieval, and Processing Perceptual Information.

    Science.gov (United States)

    McCall, Robert B.

    Function of attention in infants is explored. Assuming (1) that infants respond differently to novel situations than to familiar ones; (2) that the infant's pattern of response is a partial reflection of the process of acquiring a perceptual memory of the stimulus, and (3) that sex differences may occur in the rate of habituation, 120 infants…

  4. Perceptual Processing of Mandarin Nasals by L1 and L2 Mandarin Speakers

    Science.gov (United States)

    Lai, Yi-hsiu

    2012-01-01

    Nasals are cross-linguistically susceptible to change, especially in the syllable final position. Acoustic reports on Mandarin nasal production have recently shown that the syllable-final distinction is frequently dropped. Few studies, however, have addressed the issue of perceptual processing in Mandarin nasals for L1 and L2 speakers of Mandarin…

  5. Processing Capacity under Perceptual and Cognitive Load: A Closer Look at Load Theory

    Science.gov (United States)

    Fitousi, Daniel; Wenger, Michael J.

    2011-01-01

    Variations in perceptual and cognitive demands (load) play a major role in determining the efficiency of selective attention. According to load theory (Lavie, Hirst, Fockert, & Viding, 2004) these factors (a) improve or hamper selectivity by altering the way resources (e.g., processing capacity) are allocated, and (b) tap resources rather than…

  6. Outlining face processing skills of portrait artists: Perceptual experience with faces predicts performance.

    Science.gov (United States)

    Devue, Christel; Barsics, Catherine

    2016-10-01

    Most humans seem to demonstrate astonishingly high levels of skill in face processing if one considers the sophisticated level of fine-tuned discrimination that face recognition requires. However, numerous studies now indicate that the ability to process faces is not as fundamental as once thought and that performance can range from despairingly poor to extraordinarily high across people. Here we studied people who are super specialists of faces, namely portrait artists, to examine how their specific visual experience with faces relates to a range of face processing skills (perceptual discrimination, short- and longer term recognition). Artists show better perceptual discrimination and, to some extent, recognition of newly learned faces than controls. They are also more accurate on other perceptual tasks (i.e., involving non-face stimuli or mental rotation). By contrast, artists do not display an advantage compared to controls on longer term face recognition (i.e., famous faces) nor on person recognition from other sensorial modalities (i.e., voices). Finally, the face inversion effect exists in artists and controls and is not modulated by artistic practice. Advantages in face processing for artists thus seem to closely mirror perceptual and visual short term memory skills involved in portraiture.

  7. Action Video Games Do Not Improve the Speed of Information Processing in Simple Perceptual Tasks

    Science.gov (United States)

    van Ravenzwaaij, Don; Boekel, Wouter; Forstmann, Birte U.; Ratcliff, Roger; Wagenmakers, Eric-Jan

    2015-01-01

    Previous research suggests that playing action video games improves performance on sensory, perceptual, and attentional tasks. For instance, Green, Pouget, and Bavelier (2010) used the diffusion model to decompose data from a motion detection task and estimate the contribution of several underlying psychological processes. Their analysis indicated that playing action video games leads to faster information processing, reduced response caution, and no difference in motor responding. Because perceptual learning is generally thought to be highly context-specific, this transfer from gaming is surprising and warrants corroborative evidence from a large-scale training study. We conducted 2 experiments in which participants practiced either an action video game or a cognitive game in 5 separate, supervised sessions. Prior to each session and following the last session, participants performed a perceptual discrimination task. In the second experiment, we included a third condition in which no video games were played at all. Behavioral data and diffusion model parameters showed similar practice effects for the action gamers, the cognitive gamers, and the nongamers and suggest that, in contrast to earlier reports, playing action video games does not improve the speed of information processing in simple perceptual tasks. PMID:24933517

  8. Action video games do not improve the speed of information processing in simple perceptual tasks.

    Science.gov (United States)

    van Ravenzwaaij, Don; Boekel, Wouter; Forstmann, Birte U; Ratcliff, Roger; Wagenmakers, Eric-Jan

    2014-10-01

    Previous research suggests that playing action video games improves performance on sensory, perceptual, and attentional tasks. For instance, Green, Pouget, and Bavelier (2010) used the diffusion model to decompose data from a motion detection task and estimate the contribution of several underlying psychological processes. Their analysis indicated that playing action video games leads to faster information processing, reduced response caution, and no difference in motor responding. Because perceptual learning is generally thought to be highly context-specific, this transfer from gaming is surprising and warrants corroborative evidence from a large-scale training study. We conducted 2 experiments in which participants practiced either an action video game or a cognitive game in 5 separate, supervised sessions. Prior to each session and following the last session, participants performed a perceptual discrimination task. In the second experiment, we included a third condition in which no video games were played at all. Behavioral data and diffusion model parameters showed similar practice effects for the action gamers, the cognitive gamers, and the nongamers and suggest that, in contrast to earlier reports, playing action video games does not improve the speed of information processing in simple perceptual tasks.

  9. The role of semantic abstractness and perceptual category in processing speech accompanied by gestures

    Directory of Open Access Journals (Sweden)

    Arne eNagels

    2013-12-01

    Full Text Available Space and shape are distinct perceptual categories. In language, perceptual information can also be used to describe abstract semantic concepts like a ‘rising income’ (space or a ‘square personality’ (shape. Despite being inherently concrete, co-speech gestures depicting space and shape can accompany concrete or abstract utterances. Here, we investigated the way that abstractness influences the neural processing of the perceptual categories of space and shape in gestures. Thus, we tested the hypothesis that the neural processing of perceptual categories is highly dependent on language context.In a two-factorial design, we investigated the neural basis for the processing of gestures containing shape (SH and spatial information (SP when accompanying concrete (c or abstract (a verbal utterances. During fMRI data acquisition participants were presented with short video clips of the four conditions (cSP, aSP, cSH, aSH while performing an independent control task.Abstract (a as opposed to concrete (c utterances activated temporal lobes bilaterally and the left inferior frontal gyrus (IFG for both shape-related (SH and space-related (SP utterances. An interaction of perceptual category and semantic abstractness in a more anterior part of the left IFG and inferior part of the posterior temporal lobe indicates that abstractness strongly influenced the neural processing of space and shape information. Despite the concrete visual input of co-speech gestures in all conditions, space and shape information is processed differently depending on the semantic abstractness of its linguistic context.

  10. From perceptual to lexico-semantic analysis--cortical plasticity enabling new levels of processing.

    Science.gov (United States)

    Schlaffke, Lara; Rüther, Naima N; Heba, Stefanie; Haag, Lauren M; Schultz, Thomas; Rosengarth, Katharina; Tegenthoff, Martin; Bellebaum, Christian; Schmidt-Wilcke, Tobias

    2015-11-01

    Certain kinds of stimuli can be processed on multiple levels. While the neural correlates of different levels of processing (LOPs) have been investigated to some extent, most of the studies involve skills and/or knowledge already present when performing the task. In this study we specifically sought to identify neural correlates of an evolving skill that allows the transition from perceptual to a lexico-semantic stimulus analysis. Eighteen participants were trained to decode 12 letters of Morse code that were presented acoustically inside and outside of the scanner environment. Morse code was presented in trains of three letters while brain activity was assessed with fMRI. Participants either attended to the stimulus length (perceptual analysis), or evaluated its meaning distinguishing words from nonwords (lexico-semantic analysis). Perceptual and lexico-semantic analyses shared a mutual network comprising the left premotor cortex, the supplementary motor area (SMA) and the inferior parietal lobule (IPL). Perceptual analysis was associated with a strong brain activation in the SMA and the superior temporal gyrus bilaterally (STG), which remained unaltered from pre and post training. In the lexico-semantic analysis post learning, study participants showed additional activation in the left inferior frontal cortex (IFC) and in the left occipitotemporal cortex (OTC), regions known to be critically involved in lexical processing. Our data provide evidence for cortical plasticity evolving with a learning process enabling the transition from perceptual to lexico-semantic stimulus analysis. Importantly, the activation pattern remains task-related LOP and is thus the result of a decision process as to which LOP to engage in.

  11. Human electrophysiological reflections of the recruitment of perceptual processing during actions that engage memory.

    Science.gov (United States)

    Cruikshank, Leanna C; Caplan, Jeremy B; Singhal, Anthony

    2012-06-22

    The N170 event-related potential (ERP) component reflects visual perceptual processes and is known to have a source in the lateral occipital cortex (LOC) and temporal lobe regions. Convergent evidence from neuropsychological and neuroimaging studies suggests that the LOC is recruited for action tasks in which visibility of a target is unavailable and a perceptual memory of the target's characteristics must be used instead. We tested the hypothesis that the N170 reflects the contribution of additional ventral stream processes required for performing actions in which vision of a target is occluded. We predicted that the amplitude of the ERP in the latency range of the N170 would be larger when perceptual mechanisms are engaged to a greater extent. Participants were auditorily cued to touch target dots appearing on a touchscreen. Two viewing conditions varied with respect to the contribution of the ventral visuomotor stream during response initiation. In condition 1, the target disappeared with movement initiation whereas in condition 2, it disappeared with the cue to respond. The N170 during the response-initiation phase of trials was larger in amplitude for condition 2. The effect was observed over temporal electrode sites bilaterally, likely reflecting an overlap between auditory cue-related processes and additional perceptual processes within regions in the inferior-temporal cortex. Thus, the N170 may be a marker of neural activity within the ventral stream, further supporting the notion that actions initiated in the absence of a visual target rely more on perceptual representations than those directed towards visually available targets.

  12. Motor and perceptual sequence learning: different time course of parallel processes.

    Science.gov (United States)

    Dirnberger, Georg; Novak-Knollmueller, Judith

    2013-07-10

    The aim was to determine the extent and time course of motor and perceptual learning in a procedural learning task, and the relation of these two processes. Because environmental constraints modulate the relative impact of different learning mechanisms, we chose a simple learning task similar to real-life exercise. Thirty-four healthy individuals performed a visuomotor serial reaction time task. Learning blocks with high stimulus-response compatibility were practiced repeatedly; in between these, participants performed test blocks with the same or a different (mirror-inverted, or new) stimulus sequence and/or with the same or a different (mirror-inverted) stimulus-response allocation. This design allowed us to measure the progress of motor learning and perceptual learning independently. Results showed that in the learning blocks, a steady reduction of the reaction times indicated that - as expected - participants improved their skills continuously. Analysis of the test blocks indicated that both motor learning and perceptual learning were significant. The two mechanisms were correlated (r=0.62, Pperceptual learning was more stable but slower. In conclusion, in a simple visuomotor learning task, participants can learn the motor sequence and the stimulus sequence in parallel. The positive correlation of motor and perceptual learning suggests that the two mechanisms act in synergy and are not alternative opposing strategies. The impact of these two learning mechanisms changes over time: motor learning sets in later and becomes relevant only in the course of training.

  13. WAIS-III processing speed index scores after TBI: the influence of working memory, psychomotor speed and perceptual processing.

    Science.gov (United States)

    Kennedy, Jan E; Clement, Pamelia F; Curtiss, Glenn

    2003-08-01

    This study investigates the extent to which working memory, motor speed and perceptual processing speed influence Wechsler Adult Intelligence Scale-III (WAIS-III) Processing Speed Index (PSI) scores. Sixty-eight adult outpatients with Traumatic Brain Injury (TBI) of varying severity and complete data on all outcome measures were identified. Two cases with outlying values on one outcome measure were omitted from the final sample. Working memory was measured by the Working Memory Index score from the WAIS-III. Motor speed was measured as score on the Halstead-Reitan Finger Oscillation Test (finger tapping) and perceptual processing as score on the Trail Making Test--Part B. In hierarchical multiple regression analyses, working memory accounted for 10% of the variance in PSI scores, whereas motor speed only accounted for 3%. An independent measure of perceptual processing, Trail Making Test--B, accounted for 26% of the variance in WAIS-III PSI scores. The total variance accounted for by the three factors was 56%. Findings confirm that the WAIS-III PSI scores of individuals who have received a TBI reflect perceptual processing speed, with an additional component attributable to working memory. Motor speed made only a small contribution to WAIS-III PSI scores in the present sample.

  14. The role of perceptual load in processing distractor faces.

    Science.gov (United States)

    Lavie, Nilli; Ro, Tony; Russell, Charlotte

    2003-09-01

    It has been established that successful ignoring of irrelevant distractors depends on the extent to which the current task loads attention. However, the previous load studies have typically employed neutral distractor stimuli (e.g., letters). In the experiments reported here, we examined whether the perception of irrelevant distractor faces would show the same effects. We manipulated attentional load in a relevant task of name search by varying the search set size and found that whereas congruency effects from meaningful nonface distractors were eliminated by higher search load, interference from distractor faces was entirely unaffected by search load. These results support the idea that face processing may be mandatory and generalize the load theory to the processing of meaningful and more complex nonface distractors.

  15. Differences in early sensory-perceptual processing in synesthesia: a visual evoked potential study.

    Science.gov (United States)

    Barnett, Kylie J; Foxe, John J; Molholm, Sophie; Kelly, Simon P; Shalgi, Shani; Mitchell, Kevin J; Newell, Fiona N

    2008-11-15

    Synesthesia is a condition where stimulation of a single sensory modality or processing stream elicits an idiosyncratic, yet reliable perception in one or more other modalities or streams. Various models have been proposed to explain synesthesia, which have in common aberrant cross-activation of one cortical area by another. This has been observed directly in cases of linguistic-color synesthesia as cross-activation of the 'color area', V4, by stimulation of the grapheme area. The underlying neural substrates that mediate cross-activations in synesthesia are not well understood, however. In addition, the overall integrity of the visual system has never been assessed and it is not known whether wider differences in sensory-perceptual processing are associated with the condition. To assess whether fundamental differences in perceptual processing exist in synesthesia, we utilised high-density 128-channel electroencephalography (EEG) to measure sensory-perceptual processing using stimuli that differentially bias activation of the magnocellular and parvocellular pathways of the visual system. High and low spatial frequency gratings and luminance-contrast squares were presented to 15 synesthetes and 15 controls. We report, for the first time, early sensory-perceptual differences in synesthetes relative to non-synesthete controls in response to simple stimuli that do not elicit synesthetic color experiences. The differences are manifested in the early sensory components of the visual evoked potential (VEP) to stimuli that bias both magnocellular and parvocellular responses, but are opposite in direction, suggesting a differential effect on these two pathways. We discuss our results with reference to widespread connectivity differences as a broader phenotype of synesthesia.

  16. Perceptual load effects on processing distractor faces indicate face-specific capacity limits

    OpenAIRE

    Thoma, Volker; Lavie, Nilli

    2013-01-01

    The claim that face perception is mediated by a specialized ‘face module’ that proceeds automatically, independently of attention (e.g., Kanwisher, 2000) can be reconciled with load theory claims that visual perception has limited capacity (e.g., Lavie, 1995) by hypothesizing that face perception has face-specific capacity limits. We tested this hypothesis by comparing the effects of face and non-face perceptual load on distractor face processing. Participants searched a central array of eith...

  17. The Use of Non-linguistic Data in a Terminology and Knowledge Bank

    DEFF Research Database (Denmark)

    Madsen, Bodil Nistrup

    ‘symbol’, non-verbal form’ and ‘non-linguistic form’ – are they synonymous designations of one data category or do they designate diff erent data categories? In the presentation we will discuss defi nitions from e.g. ISOcat, ISO 704:2009 and the DanTermBank taxonomy of terminological data categories......, and we will present some thoughts about the relevance of non-linguistic information in a national term bank....

  18. Age-related face processing bias in infancy: evidence of perceptual narrowing for adult faces.

    Science.gov (United States)

    Macchi Cassia, Viola; Bulf, Hermann; Quadrelli, Ermanno; Proietti, Valentina

    2014-02-01

    Recent data demonstrate a perceptual processing advantage for adult faces in both adults and young children, suggesting that face representation is shaped by visual experience accumulated with different face-age groups. As for species and race, this age bias may emerge during the first year of life as part of the general process of perceptual narrowing, given the extensive amount of social and perceptual experience accumulated with caregivers and/or other adult individuals. Using infant-controlled habituation and visual-paired comparison at test, two experiments were carried out to examine 3- and 9-month-olds' ability to discriminate within adult and infant faces. Results showed that, when they are provided with adequate time to visually compare the stimuli during test trials (Experiment 2), 3-month-olds exhibit above-chance discrimination of adult and infant faces. Instead, 9-month-olds discriminate adult faces but not infant faces (Experiments 1 and 2). Results provide the first evidence of age-related face processing biases in infancy, and show that by 9 months face representations tune to adult human faces.

  19. Time-course of perceptual processing of "hole" and "no-hole"figures: An ERP study

    Institute of Scientific and Technical Information of China (English)

    Weina Zhu; Junjun Zhang; Changle Zhou

    2013-01-01

    Closure or the presence of a "hole" is an emergent perceptual feature that can be extracted by the visual system early on.This feature has been shown to have perceptual advantages over openness or "no-hole".In this study,we investigated when and how the human brain differentiates between "hole" and "no-hole" figures.Event-related potentials (ERPs) were recorded during a passive observation paradigm.Two pairs of simple figures (Experiment 1) and two sets of Greek letters (Experiment 2) were used as stimuli.The ERPs of "hole" and "no-hole"figures differed ~90 ms after stimulus onset:"hole"figures elicited smaller P1 and N1 amplitudes than "no-hole" figures.These suggest that both P1 and N1 components are sensitive to the difference between "hole" and "no-hole" figures; perception of "hole" and "no-hole" figures might be differentiated early during visual processing.

  20. Navigated transcranial magnetic stimulation of the primary somatosensory cortex impairs perceptual processing of tactile temporal discrimination.

    Science.gov (United States)

    Hannula, Henri; Neuvonen, Tuomas; Savolainen, Petri; Tukiainen, Taru; Salonen, Oili; Carlson, Synnöve; Pertovaara, Antti

    2008-05-30

    Previous studies indicate that transcranial magnetic stimulation (TMS) with biphasic pulses applied approximately over the primary somatosensory cortex (S1) suppresses performance in vibrotactile temporal discrimination tasks; these previous results, however, do not allow separating perceptual influence from memory or decision-making. Moreover, earlier studies using external landmarks for directing biphasic TMS pulses to the cortex do not reveal whether the changes in vibrotactile task performance were due to action on S1 or an adjacent area. In the present study, we determined whether the S1 area representing a cutaneous test site is critical for perceptual processing of tactile temporal discrimination. Electrical test pulses were applied to the thenar skin of the hand and the subjects attempted to discriminate single from twin pulses. During discrimination task, monophasic TMS pulses or sham TMS pulses were directed anatomically accurately to the S1 area representing the thenar using magnetic resonance image-guided navigation. The subject's capacity to temporal discrimination was impaired with a decrease in the delay between the TMS pulse and the cutaneous test pulse from 50 to 0 ms. The result indicates that S1 area representing a cutaneous test site is involved in perceptual processing of tactile temporal discrimination.

  1. Children with speech sound disorder: Comparing a non-linguistic auditory approach with a phonological intervention approach to improve phonological skills

    Directory of Open Access Journals (Sweden)

    Cristina eMurphy

    2015-02-01

    Full Text Available This study aimed to compare the effects of a non-linguistic auditory intervention approach with a phonological intervention approach on the phonological skills of children with speech sound disorder. A total of 17 children, aged 7-12 years, with speech sound disorder were randomly allocated to either the non-linguistic auditory temporal intervention group (n = 10, average age 7.7 ± 1.2 or phonological intervention group (n = 7, average age 8.6 ± 1.2. The intervention outcomes included auditory-sensory measures (auditory temporal processing skills and cognitive measures (attention, short-term memory, speech production and phonological awareness skills. The auditory approach focused on non-linguistic auditory training (eg. backward masking and frequency discrimination, whereas the phonological approach focused on speech sound training (eg. phonological organisation and awareness. Both interventions consisted of twelve 45-minute sessions delivered twice per week, for a total of nine hours. Intra-group analysis demonstrated that the auditory intervention group showed significant gains in both auditory and cognitive measures, whereas no significant gain was observed in the phonological intervention group. No significant improvement on phonological skills was observed in any of the groups. Inter-group analysis demonstrated significant differences between the improvement following training for both groups, with a more pronounced gain for the non-linguistic auditory temporal intervention in one of the visual attention measures and both auditory measures. Therefore, both analyses suggest that although the non-linguistic auditory intervention approach appeared to be the most effective intervention approach, it was not sufficient to promote the enhancement of phonological skills.

  2. Visual speech information: a help or hindrance in perceptual processing of dysarthric speech.

    Science.gov (United States)

    Borrie, Stephanie A

    2015-03-01

    This study investigated the influence of visual speech information on perceptual processing of neurologically degraded speech. Fifty listeners identified spastic dysarthric speech under both audio (A) and audiovisual (AV) conditions. Condition comparisons revealed that the addition of visual speech information enhanced processing of the neurologically degraded input in terms of (a) acuity (percent phonemes correct) of vowels and consonants and (b) recognition (percent words correct) of predictive and nonpredictive phrases. Listeners exploited stress-based segmentation strategies more readily in AV conditions, suggesting that the perceptual benefit associated with adding visual speech information to the auditory signal-the AV advantage-has both segmental and suprasegmental origins. Results also revealed that the magnitude of the AV advantage can be predicted, to some degree, by the extent to which an individual utilizes syllabic stress cues to inform word recognition in AV conditions. Findings inform the development of a listener-specific model of speech perception that applies to processing of dysarthric speech in everyday communication contexts.

  3. Susceptibility to a multisensory speech illusion in older persons is driven by perceptual processes

    Directory of Open Access Journals (Sweden)

    Annalisa eSetti

    2013-09-01

    Full Text Available Recent studies suggest that multisensory integration is enhanced in older adults but it is not known whether this enhancement is solely driven by perceptual processes or affected by cognitive processes. Using the ‘McGurk illusion’, in Experiment 1 we found that audio-visual integration of incongruent audio-visual words was higher in older adults than in younger adults, although the recognition of either audio- or visual-only presented words was the same across groups. In Experiment 2 we tested recall of sentences within which an incongruent audio-visual speech word was embedded. The overall semantic meaning of the sentence was compatible with either one of the unisensory components of the target word and/or with the illusory percept. Older participants recalled more illusory audio-visual words in sentences than younger adults, however, there was no differential effect of word compatibility on recall for the two groups. Our findings suggest that the relatively high susceptibility to the audio-visual speech illusion in older participants is due more to perceptual than cognitive processing.

  4. The Use of Non-linguistic Data in a Terminology and Knowledge Bank

    DEFF Research Database (Denmark)

    Madsen, Bodil Nistrup

    2016-01-01

    This paper will discuss definitions and give examples of linguistic and non -linguistic representation of concepts in a terminology and knowledge bank, and it will be argued that there is a need for a taxonomy of terminological data categories. As a background the DanTermBank project, which...... to the structure of ISOcat, the first printed standard comprising data categories for terminology management, ISO 12620:1999, and other standards from ISO TC 37. Finally some examples of linguistic and non-linguistic representations of concepts which we plan to introduce into the DanTermBank will be presented....

  5. Empathy for pain influences perceptual and motor processing: Evidence from response force, ERPs, and EEG oscillations.

    Science.gov (United States)

    Fabi, Sarah; Leuthold, Hartmut

    2016-09-28

    In the present study we investigated the nature and chronometry of empathy for pain influences on perceptual and motor processes. Thus, event-related brain potentials (ERPs), response force (RF) and oscillatory electroencephalography (EEG) activity were measured while participants were presented with pictures of body parts in painful or neutral situations. Their task consisted in either judging the painfulness of the stimuli or counting the body parts displayed. ERP results supported the assumption of an early automatic component of empathy for pain, as reflected by the early posterior negativity (EPN), and of a late controlled component, as reflected by the late posterior positivity (P3). RF indicated that empathy-evoking stimuli facilitate motor responses if attention is directed toward the pain dimension, whereas EEG oscillations in the mu-and beta-band revealed, independent of the task, an enhanced activation of the sensorimotor cortex after the response to painful compared to neutral stimuli. In conclusion, present findings indicate that empathy-evoking stimuli produce automatic and controlled effects on both perceptual and motor processing.

  6. Gamma band activity and the P3 reflect post-perceptual processes, not visual awareness.

    Science.gov (United States)

    Pitts, Michael A; Padwal, Jennifer; Fennelly, Daniel; Martínez, Antígona; Hillyard, Steven A

    2014-11-01

    A primary goal in cognitive neuroscience is to identify neural correlates of conscious perception (NCC). By contrasting conditions in which subjects are aware versus unaware of identical visual stimuli, a number of candidate NCCs have emerged; among them are induced gamma band activity in the EEG and the P3 event-related potential. In most previous studies, however, the critical stimuli were always directly relevant to the subjects' task, such that aware versus unaware contrasts may well have included differences in post-perceptual processing in addition to differences in conscious perception per se. Here, in a series of EEG experiments, visual awareness and task relevance were manipulated independently. Induced gamma activity and the P3 were absent for task-irrelevant stimuli regardless of whether subjects were aware of such stimuli. For task-relevant stimuli, gamma and the P3 were robust and dissociable, indicating that each reflects distinct post-perceptual processes necessary for carrying-out the task but not for consciously perceiving the stimuli. Overall, this pattern of results challenges a number of previous proposals linking gamma band activity and the P3 to conscious perception.

  7. Automatic perceptual simulation of first language meanings during second language sentence processing in bilinguals.

    Science.gov (United States)

    Vukovic, Nikola; Williams, John N

    2014-01-01

    Research supports the claim that, when understanding language, people perform mental simulation using those parts of the brain which support sensation, action, and emotion. A major criticism of the findings quoted as evidence for embodied simulation, however, is that they could be a result of conscious image generation strategies. Here we exploit the well-known fact that bilinguals routinely and automatically activate both their languages during comprehension to test whether this automatic process is, in turn, modulated by embodied simulatory processes. Dutch participants heard English sentences containing interlingual homophones and implying specific distance relations, and had to subsequently respond to pictures of objects matching or mismatching this implied distance. Participants were significantly slower to reject critical items when their perceptual features matched said distance relationship. These results suggest that bilinguals not only activate task-irrelevant meanings of interlingual homophones, but also automatically simulate these meanings in a detailed perceptual fashion. Our study supports the claim that embodied simulation is not due to participants' conscious strategies, but is an automatic component of meaning construction. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Modelling social interaction as perceptual crossing: an investigation into the dynamics of the interaction process

    Science.gov (United States)

    Froese, Tom; Di Paolo, Ezequiel A.

    2010-03-01

    This paper continues efforts to establish a mutually informative dialogue between psychology and evolutionary robotics in order to investigate the dynamics of social interaction. We replicate a recent simulation model of a minimalist experiment in perceptual crossing and confirm the results with significantly simpler artificial agents. A series of psycho-physical tests of their behaviour informs a hypothetical circuit model of their internal operation. However, a detailed study of the actual internal dynamics reveals this circuit model to be unfounded, thereby offering a tale of caution for those hypothesising about sub-personal processes in terms of behavioural observations. In particular, it is shown that the behaviour of the agents largely emerges out of the interaction process itself rather than being an individual achievement alone. We also extend the original simulation model in two novel directions in order to test further the extent to which perceptual crossing between agents can self-organise in a robust manner. These modelling results suggest new hypotheses that can become the basis for further psychological experiments.

  9. Two components in IOR: evidence for response bias and perceptual processing delays using the SAT methodology.

    Science.gov (United States)

    Zhao, Yuanyuan; Heinke, Dietmar; Ivanoff, Jason; Klein, Raymond M; Humphreys, Glyn W

    2011-10-01

    Inhibition of return (IOR) occurs when reaction times (RTs) are slowed to respond to a target that appears at a previously attended location. We used the speed-accuracy trade-off (SAT) procedure to obtain conjoint measures of IOR on sensitivity and processing speed by presenting targets at cued and uncued locations. The results showed that IOR is associated with both delays in processing speed and shifts in response criterion. When the target was briefly presented, the results supported a criterion shift account of IOR. However, when the target was presented until response, the evidence indicated that, in addition to a response bias effect, there was an increase in the minimal time required for information about the target to accumulate above chance level. A hybrid account of IOR is suggested that describes effects on both response bias and perceptual processing.

  10. The Processing of Biologically Plausible and Implausible forms in American Sign Language: Evidence for Perceptual Tuning.

    Science.gov (United States)

    Almeida, Diogo; Poeppel, David; Corina, David

    The human auditory system distinguishes speech-like information from general auditory signals in a remarkably fast and efficient way. Combining psychophysics and neurophysiology (MEG), we demonstrate a similar result for the processing of visual information used for language communication in users of sign languages. We demonstrate that the earliest visual cortical responses in deaf signers viewing American Sign Language (ASL) signs show specific modulations to violations of anatomic constraints that would make the sign either possible or impossible to articulate. These neural data are accompanied with a significantly increased perceptual sensitivity to the anatomical incongruity. The differential effects in the early visual evoked potentials arguably reflect an expectation-driven assessment of somatic representational integrity, suggesting that language experience and/or auditory deprivation may shape the neuronal mechanisms underlying the analysis of complex human form. The data demonstrate that the perceptual tuning that underlies the discrimination of language and non-language information is not limited to spoken languages but extends to languages expressed in the visual modality.

  11. Perceptual image quality in normalized LOG domain for Adaptive Optics image post-processing

    Science.gov (United States)

    Guo, Shiping; Zhang, Rongzhi; Li, Jisheng; Zou, Jianhua; Liu, Changhai; Gao, Weizhe

    2015-08-01

    Adaptive Optics together with subsequent post-processing techniques obviously improve the resolution of turbulencedegraded images in ground-based space objects detection and identification. The most common method for frame selection and stopping iteration in post-processing has always been subjective viewing of the images due to a lack of widely agreed-upon objective quality metric. Full reference metrics are not applicable for assessing the field data, no-reference metrics tend to perform poor sensitivity for Adaptive Optics images. In the present work, based on the Laplacian of Gaussian (LOG) local contrast feature, a nonlinear normalization is applied to transform the input image into a normalized LOG domain; a quantitative index is then extracted in this domain to assess the perceptual image quality. Experiments show this no-reference quality index is highly consistent with the subjective evaluation of input images for different blur degree and different iteration number.

  12. Neurophysiological marker of inhibition distinguishes language groups on a non-linguistic executive function test.

    Science.gov (United States)

    Fernandez, M; Tartar, J L; Padron, D; Acosta, J

    2013-12-01

    Successful interaction with the environment depends on flexible behaviors which require shifting attention, inhibiting primed responses, ignoring distracting information, and withholding motor responses. These abilities, termed executive function (EF), are believed to be mediated by inhibitory processes in the frontal lobes. Superior performance on EF tests (i.e., faster reaction times (RT), and fewer errors) has been shown in bilinguals compared to monolingual speakers. However, findings are inconsistent, and no study has directly linked this bilingual advantage to frontal lobe inhibitory processes. To clarify this uncertainty, we concomitantly tested neural inhibitory processes and behavioral responses on an EF test in bilinguals and monolinguals. Specifically, we compared English monolinguals (N=15) to Spanish/English bilinguals (N=13) on event-related brain potentials (ERP) during a non-linguistic, auditory Go/NoGo task, a task linked to non-motor, cognitive inhibition in monolinguals. Participants responded with a button press on trials in which target tone-pairs (Go trials) were presented and withheld their responses on non-target trials (NoGo trials). Results revealed significantly greater inhibition (i.e., greater mean N2 amplitude) in bilinguals compared to monolinguals during NoGo trials even though both groups performed the task equally well (i.e., withheld a motor response). On Go trials where participants pressed a response button, neither ERPs nor RT distinguished the groups. Additionally, scores on a second language proficiency test (i.e., English in our bilingual group) were positively correlated with N2 amplitude. These findings are the first to directly link this bilingual advantage to a neural correlate of inhibition and to reveal that inhibition in bilinguals is moderated by second language proficiency. Results are discussed in the context of plasticity, and we propose that evaluating bilinguals at varying levels of second-language proficiency

  13. The Use of Non-linguistic Data in a Terminology and Knowledge Bank

    DEFF Research Database (Denmark)

    Madsen, Bodil Nistrup

    2016-01-01

    This paper will discuss definitions and give examples of linguistic and non -linguistic representation of concepts in a terminology and knowledge bank, and it will be argued that there is a need for a taxonomy of terminological data categories. As a background the DanTermBank project, which is ca...

  14. Do Non-Linguists Practice Linguistics?: An Anti-Eliminative Approach to Folk Theories

    Science.gov (United States)

    Paveau, Marie-Anne

    2011-01-01

    This contribution discusses two issues: (a) it provides a definition and an analysis of the term "non-linguist", which is conceptualized as a non-discrete category on a continuum and as an activity rather than as a permanent status, and (b) it discusses the general value of folk linguistic theories, which should not, despite their potential…

  15. The Influence of Perceptual and Semantic Categorization on Inhibitory Processing as Measured by the N2-P3 Response

    Science.gov (United States)

    Maguire, Mandy J.; Brier, Matthew R.; Moore, Patricia S.; Ferree, Thomas C.; Ray, Dylan; Mostofsky, Stewart; Hart, John, Jr.; Kraut, Michael A.

    2009-01-01

    In daily activities, humans must attend and respond to a range of important items and inhibit and not respond to unimportant distractions. Our current understanding of these processes is largely based on perceptually simple stimuli. This study investigates the interaction of conceptual-semantic categorization and inhibitory processing using Event…

  16. A predictive processing theory of sensorimotor contingencies: Explaining the puzzle of perceptual presence and its absence in synesthesia.

    Science.gov (United States)

    Seth, Anil K

    2014-01-01

    Normal perception involves experiencing objects within perceptual scenes as real, as existing in the world. This property of "perceptual presence" has motivated "sensorimotor theories" which understand perception to involve the mastery of sensorimotor contingencies. However, the mechanistic basis of sensorimotor contingencies and their mastery has remained unclear. Sensorimotor theory also struggles to explain instances of perception, such as synesthesia, that appear to lack perceptual presence and for which relevant sensorimotor contingencies are difficult to identify. On alternative "predictive processing" theories, perceptual content emerges from probabilistic inference on the external causes of sensory signals, however, this view has addressed neither the problem of perceptual presence nor synesthesia. Here, I describe a theory of predictive perception of sensorimotor contingencies which (1) accounts for perceptual presence in normal perception, as well as its absence in synesthesia, and (2) operationalizes the notion of sensorimotor contingencies and their mastery. The core idea is that generative models underlying perception incorporate explicitly counterfactual elements related to how sensory inputs would change on the basis of a broad repertoire of possible actions, even if those actions are not performed. These "counterfactually-rich" generative models encode sensorimotor contingencies related to repertoires of sensorimotor dependencies, with counterfactual richness determining the degree of perceptual presence associated with a stimulus. While the generative models underlying normal perception are typically counterfactually rich (reflecting a large repertoire of possible sensorimotor dependencies), those underlying synesthetic concurrents are hypothesized to be counterfactually poor. In addition to accounting for the phenomenology of synesthesia, the theory naturally accommodates phenomenological differences between a range of experiential states

  17. The neural processes underlying perceptual decision making in humans: recent progress and future directions.

    Science.gov (United States)

    Kelly, Simon P; O'Connell, Redmond G

    2015-01-01

    In the last two decades, animal neurophysiology research has made great strides towards explaining how the brain can enable adaptive action in the face of noisy sensory information. In particular, this work has identified neural signals that perform the role of a 'decision variable' which integrates sensory information in favor of a particular outcome up to an action-triggering threshold, consistent with long-standing predictions from mathematical psychology. This has provoked an intensive search for similar neural processes at work in the human brain. In this paper we review the progress that has been made in tracing the dynamics of perceptual decision formation in humans using functional imaging and electrophysiology. We highlight some of the limitations that non-invasive recording techniques place on our ability to make definitive judgments regarding the role that specific signals play in decision making. Finally, we provide an overview of our own work in this area which has focussed on two perceptual tasks - intensity change detection and motion discrimination - performed under continuous-monitoring conditions, and highlight the insights gained thus far. We show that through simple paradigm design features such as avoiding sudden intensity transients at evidence onset, a neural instantiation of the theoretical decision variable can be directly traced in the form of a centro-parietal positivity (CPP) in the standard event-related potential (ERP). We recapitulate evidence for the domain-general nature of the CPP process, being divorced from the sensory and motor requirements of the task, and re-plot data of both tasks highlighting this aspect as well as its relationship to decision outcome and reaction time. We discuss the implications of these findings for mechanistically principled research on normal and abnormal decision making in humans.

  18. Literacy affects spoken language in a non-linguistic task: An ERP study

    Directory of Open Access Journals (Sweden)

    Laetitia ePerre

    2011-10-01

    Full Text Available It is now commonly accepted that orthographic information influences spoken word recognition in a variety of laboratory tasks (lexical decision, semantic categorization, gender decision. However, it remains a hotly debated issue whether or not orthography would influence normal word perception in passive listening. That is, the argument has been made that orthography might only be activated in laboratory tasks that require lexical or semantic access in some form or another. It is possible that these rather unnatural tasks invite participants to use orthographic information in a strategic way to improve task performance. To put the strategy account to rest, we conducted an event-related brain potential (ERP study, in which participants were asked to detect a 500ms-long noise burst that appeared on 25% of the trials (Go trials. In the NoGo trials, we presented spoken words that were orthographically consistent or inconsistent. Thus, lexical and/or semantic processing was not required in this task and there was no strategic benefit in computing orthography to perform this task. Nevertheless, despite the non-linguistic nature of the task, we replicated the consistency effect that has been previously reported in lexical decision and semantic tasks (i.e., inconsistent words produce more negative ERPs than consistent words as early as 300 ms after the onset of the spoken word.. These results clearly suggest that orthography automatically influences word perception in normal listening even if there is no strategic benefit to do so. The results are explained in terms of orthographic restructuring of phonological representations.

  19. The Impact of Perceptual/Concurrent and Mnemonic Digits on Temporal Processing: A Congruency Effect of Numerical Magnitudes.

    Science.gov (United States)

    Fan, Zhao; Jing, Guomin; Ding, Xianfeng; Cheng, Xiaorong

    2016-01-01

    Task-irrelevant stimulus numbers can automatically modulate concurrent temporal tasks--leading to the phenomenon of number-time association (NTA). Recent research provides converging evidence that the NTA occurs at the stage of temporal memory. Specifically, a reference memory containing encoded duration information can be modified by perceptual/concurrent digits, i.e., a perceptual/concurrent digit-induced NTA. Here, with five experiments, we investigated whether another working memory (WM)-related mechanism was involved in the generation of NTAs and how this memory-induced NTA was related with the perception-induced NTA. We first explored whether similar NTA effects existed for mnemonic digits which disappeared before time encoding but were actively maintained in WM, i.e., a mnemonic digit-induced NTA. Experiments 1-3 demonstrated both types of NTAs. Further, we revealed a close relationship between the two types of NTAs in two contexts. First, the mnemonic digit-induced NTA also relied on a perceptual number-time co-occurrence at time encoding. We found that the mnemonic digits influenced subsequent temporal processing when a task-irrelevant constant number '5' was presented during target encoding, but not when a non-numerical symbol was presented, suggesting that temporal representations in the reference memory could be accessed and modified by both sensory and postsensory numerical magnitudes through this number-time co-occurrence. Second, the effects of perceptual and mnemonic digits on temporal reproduction could cancel each other out. A congruency effect for perceptual and mnemonic digits (relying on memorization requirement) was demonstrated in Experiments 4 and 5. Specifically, a typical NTA was observed when the magnitudes of memorized and the perceptual/concurrent digits were congruent (both were large or small numbers), but not when they were incongruent (one small and one large numbers). Taken together, our study sheds new light on the mechanism of

  20. CONDITIONS FOR OVERCOMING COMMUNICATION-LANGUAGE BARRIERS IN THE SYSTEM OF NON-LINGUISTIC HIGHER EDUCATION

    Directory of Open Access Journals (Sweden)

    Lidiya Olegovna Polyakova

    2016-01-01

    Results. Results of our scientific work are such conditions should be implemented based on the principle of «vertical integration», covering the social levels of the customer of higher education (economic sector, national systems of higher education, the University, the faculty, the chair. Practical implications. Presents a set of tools that is effective in solving problems of communication-language barriers of future specialists of non-linguistic profile.

  1. APPLICATION OF THE COMMUNICATIVE METHOD IN TEACHING FOREIGN LANGUAGES IN A NON-LINGUISTIC MILITARY COLLEGE

    Directory of Open Access Journals (Sweden)

    Gennady Ivanovich SHEMET

    2014-01-01

    Full Text Available The article is dedicated to the problem of exploring and developing new methods and techniques in teaching foreign languages in a non-linguistic military college. The article presents the design and the results of an educa-tional experiment on checking the efficiency of commu-nicative teaching method for translation skills formation in the course of language training in the Cherepovets higher military engineering college of radio-electronics.

  2. Perceptual grouping does not affect multi-attribute decision making if no processing costs are involved.

    Science.gov (United States)

    Ettlin, Florence; Bröder, Arndt

    2015-05-01

    Adaptive strategy selection implies that a decision strategy is chosen based on its fit to the task and situation. However, other aspects, such as the way information is presented, can determine information search behavior; especially when the application of certain strategies over others is facilitated. But are such display effects on multi-attribute decisions also at work when the manipulation does not entail differential costs for different decision strategies? Three Mouselab experiments with hidden information and one eye tracking experiment with an open information board revealed that decision behavior is unaffected by purely perceptual manipulations of the display based on Gestalt principles; that is, based on manipulations that induce no noteworthy processing costs for different information search patterns. We discuss our results in the context of previous findings on display effects; specifically, how the combination of these findings and our results reveal the crucial role of differential processing costs for different strategies for the emergence of display effects. This finding describes a boundary condition of the commonly acknowledged influence of information displays and is in line with the ideas of adaptive strategy selection and cost-benefit tradeoffs.

  3. Fusiform gyrus dysfunction is associated with perceptual processing efficiency to emotional faces in adolescent depression: a model-based approach

    Directory of Open Access Journals (Sweden)

    Tiffany Cheing Ho

    2016-02-01

    Full Text Available While the extant literature has focused on major depressive disorder (MDD as being characterized by abnormalities in processing affective stimuli (e.g., facial expressions, little is known regarding which specific aspects of cognition influence the evaluation of affective stimuli, and what are the underlying neural correlates. To investigate these issues, we assessed 26 adolescents diagnosed with MDD and 37 well-matched healthy controls (HCL who completed an emotion identification task of dynamically morphing faces during functional magnetic resonance imaging (fMRI. We analyzed the behavioral data using a sequential sampling model of response time (RT commonly used to elucidate aspects of cognition in binary perceptual decision making tasks: the Linear Ballistic Accumulator (LBA model. Using a hierarchical Bayesian estimation method, we obtained group-level and individual-level estimates of LBA parameters on the facial emotion identification task. While the MDD and HCL groups did not differ in mean RT, accuracy, or group-level estimates of perceptual processing efficiency (i.e., drift rate parameter of the LBA, the MDD group showed significantly reduced responses in left fusiform gyrus compared to the HCL group during the facial emotion identification task. Furthermore, within the MDD group, fMRI signal in the left fusiform gyrus during affective face processing was significantly associated with greater individual-level estimates of perceptual processing efficiency. Our results therefore suggest that affective processing biases in adolescents with MDD are characterized by greater perceptual processing efficiency of affective visual information in sensory brain regions responsible for the early processing of visual information. The theoretical, methodological, and clinical implications of our results are discussed.

  4. Do perceptual biases emerge early or late in visual processing? Decision-biases in motion perception.

    Science.gov (United States)

    Zamboni, Elisa; Ledgeway, Timothy; McGraw, Paul V; Schluppeck, Denis

    2016-06-29

    Visual perception is strongly influenced by contextual information. A good example is reference repulsion, where subjective reports about the direction of motion of a stimulus are significantly biased by the presence of an explicit reference. These perceptual biases could arise early, during sensory encoding, or alternatively, they may reflect decision-related processes occurring relatively late in the task sequence. To separate these two competing possibilities, we asked (human) subjects to perform a fine motion-discrimination task and then estimate the direction of motion in the presence or absence of an oriented reference line. When subjects performed the discrimination task with the reference, but subsequently estimated motion direction in its absence, direction estimates were unbiased. However, when subjects viewed the same stimuli but performed the estimation task only, with the orientation of the reference line jittered on every trial, the directions estimated by subjects were biased and yoked to the orientation of the shifted reference line. These results show that judgements made relative to a reference are subject to late, decision-related biases A model in which information about motion is integrated with that of an explicit reference cue, resulting in a late, decision-related re-weighting of the sensory representation, can account for these results.

  5. Perceptual face processing in developmental prosopagnosia is not sensitive to the canonical location of face parts.

    Science.gov (United States)

    Towler, John; Parketny, Joanna; Eimer, Martin

    2016-01-01

    Individuals with developmental prosopagnosia (DP) are strongly impaired in recognizing faces, but it is controversial whether this deficit is linked to atypical visual-perceptual face processing mechanisms. Previous behavioural studies have suggested that face perception in DP might be less sensitive to the canonical spatial configuration of face parts in upright faces. To test this prediction, we recorded event-related brain potentials (ERPs) to intact upright faces and to faces with spatially scrambled parts (eyes, nose, and mouth) in a group of ten participants with DP and a group of ten age-matched control participants with normal face recognition abilities. The face-sensitive N170 component and the vertex positive potential (VPP) were both enhanced and delayed for scrambled as compared to intact faces in the control group. In contrast, N170 and VPP amplitude enhancements to scrambled faces were absent in the DP group. For control participants, the N170 to scrambled faces was also sensitive to feature locations, with larger and delayed N170 components contralateral to the side where all features appeared in a non-canonical position. No such differences were present in the DP group. These findings suggest that spatial templates of the prototypical feature locations within an upright face are selectively impaired in DP.

  6. TYPOLOGIZATION OF SOCIO-CULTURAL EXERCISES FOR DEVELOPMENT OF AUDIO-VISIAL RECEPTION SKILLS OF NON-LINGUISTIC UNIVERSITY STUDENTS

    OpenAIRE

    Наталья Владимировна Базина

    2014-01-01

    The article describes principles of building a complex of socio-cultural exercises intended for the materials of German TV to be used in training students of non-linguistic universities with under-threshold level of German language skills. Besides that the types of German language exercises for the students of non-linguistic universities are given where students study German as second language in the context of socio-cultural and competence approach for preparation of international journalist...

  7. Separate Perceptual and Neural Processing of Velocity- and Disparity-Based 3D Motion Signals.

    Science.gov (United States)

    Joo, Sung Jun; Czuba, Thaddeus B; Cormack, Lawrence K; Huk, Alexander C

    2016-10-19

    Although the visual system uses both velocity- and disparity-based binocular information for computing 3D motion, it is unknown whether (and how) these two signals interact. We found that these two binocular signals are processed distinctly at the levels of both cortical activity in human MT and perception. In human MT, adaptation to both velocity-based and disparity-based 3D motions demonstrated direction-selective neuroimaging responses. However, when adaptation to one cue was probed using the other cue, there was no evidence of interaction between them (i.e., there was no "cross-cue" adaptation). Analogous psychophysical measurements yielded correspondingly weak cross-cue motion aftereffects (MAEs) in the face of very strong within-cue adaptation. In a direct test of perceptual independence, adapting to opposite 3D directions generated by different binocular cues resulted in simultaneous, superimposed, opposite-direction MAEs. These findings suggest that velocity- and disparity-based 3D motion signals may both flow through area MT but constitute distinct signals and pathways. Recent human neuroimaging and monkey electrophysiology have revealed 3D motion selectivity in area MT, which is driven by both velocity-based and disparity-based 3D motion signals. However, to elucidate the neural mechanisms by which the brain extracts 3D motion given these binocular signals, it is essential to understand how-or indeed if-these two binocular cues interact. We show that velocity-based and disparity-based signals are mostly separate at the levels of both fMRI responses in area MT and perception. Our findings suggest that the two binocular cues for 3D motion might be processed by separate specialized mechanisms. Copyright © 2016 the authors 0270-6474/16/3610791-12$15.00/0.

  8. Dissociating the Neural Basis of Conceptual Self-Awareness from Perceptual Awareness and Unaware Self-Processing.

    Science.gov (United States)

    Tacikowski, Pawel; Berger, Christopher C; Ehrsson, H Henrik

    2017-01-23

    Conceptual self-awareness is a mental state in which the content of one's consciousness refers to a particular aspect of semantic knowledge about oneself. This form of consciousness plays a crucial role in shaping human behavior; however, little is known about its neural basis. Here, we use functional magnetic resonance imaging (fMRI) and a visual masked priming paradigm to dissociate the neural responses related to the awareness of semantic autobiographical information (one's own name, surname, etc.) from the awareness of information related to any visual stimulus (perceptual awareness), as well as from the unaware processing of self-relevant stimuli. To detect brain activity that is highly selective for self-relevant information, we used the blood-oxygen-level-dependent (BOLD) adaptation approach, which goes beyond the spatial limitations of conventional fMRI. We found that self-awareness was associated with BOLD adaptation in the medial frontopolar-retrosplenial areas, whereas perceptual awareness and unaware self-processing were associated with BOLD adaptation in the lateral fronto-parietal areas and the inferior temporal cortex, respectively. Thus, using a direct manipulation of conscious awareness we demonstrate for the first time that the neural basis of conceptual self-awareness is neuroanatomically distinct from the network mediating perceptual awareness of the sensory environment or unaware processing of self-related stimuli. © The Author 2017. Published by Oxford University Press.

  9. Thresholds of visibility for masked lexical, non-lexical, and non-linguistic items in aphasia

    Directory of Open Access Journals (Sweden)

    JoAnn P Silkes

    2015-04-01

    Data collected to date demonstrate a clear difference between individuals with and without aphasia in their ability to perceive masked real words, but there appears to be no difference between groups for non-words and non-linguistic stimuli, although a trend is seen for these groups. Given the high variability for the NW and NL conditions, these analyses may be underpowered; therefore, data collection is ongoing and a clearer picture should be available by the time of presentation. Regardless of the eventual outcome, this poster will discuss the theoretical motivation for the study, and will discuss the possible implications for understanding the nature of underlying deficits in aphasia.

  10. Gestalt Processing in Autism: Failure to Process Perceptual Relationships and the Implications for Contextual Understanding

    Science.gov (United States)

    Brosnan, Mark J.; Scott, Fiona J.; Fox, Simone; Pye, Jackie

    2004-01-01

    Background: Deficits in autism have been characterised as a bias towards local over global processing. This paper examines whether there is a deficit in gestalt grouping in autism. Method: Twenty-five low-functioning children with autism and 25 controls who were matched for chronological age and verbal mental age took part in the study. Results:…

  11. Gestalt Processing in Autism: Failure to Process Perceptual Relationships and the Implications for Contextual Understanding

    Science.gov (United States)

    Brosnan, Mark J.; Scott, Fiona J.; Fox, Simone; Pye, Jackie

    2004-01-01

    Background: Deficits in autism have been characterised as a bias towards local over global processing. This paper examines whether there is a deficit in gestalt grouping in autism. Method: Twenty-five low-functioning children with autism and 25 controls who were matched for chronological age and verbal mental age took part in the study. Results:…

  12. Action video games do not improve the speed of information processing in simple perceptual tasks

    NARCIS (Netherlands)

    D. van Ravenzwaaij; W. Boekel; B.U. Forstmann; R. Ratcliff; E.-J. Wagenmakers

    2014-01-01

    Previous research suggests that playing action video games improves performance on sensory, perceptual, and attentional tasks. For instance, Green, Pouget, and Bavelier (2010) used the diffusion model to decompose data from a motion detection task and estimate the contribution of several underlying

  13. Cross-cultural decoding of positive and negative non-linguistic emotion vocalizations

    Science.gov (United States)

    Laukka, Petri; Elfenbein, Hillary Anger; Söder, Nela; Nordström, Henrik; Althoff, Jean; Chui, Wanda; Iraki, Frederick K.; Rockstuhl, Thomas; Thingujam, Nutankumar S.

    2013-01-01

    Which emotions are associated with universally recognized non-verbal signals?We address this issue by examining how reliably non-linguistic vocalizations (affect bursts) can convey emotions across cultures. Actors from India, Kenya, Singapore, and USA were instructed to produce vocalizations that would convey nine positive and nine negative emotions to listeners. The vocalizations were judged by Swedish listeners using a within-valence forced-choice procedure, where positive and negative emotions were judged in separate experiments. Results showed that listeners could recognize a wide range of positive and negative emotions with accuracy above chance. For positive emotions, we observed the highest recognition rates for relief, followed by lust, interest, serenity and positive surprise, with affection and pride receiving the lowest recognition rates. Anger, disgust, fear, sadness, and negative surprise received the highest recognition rates for negative emotions, with the lowest rates observed for guilt and shame. By way of summary, results showed that the voice can reveal both basic emotions and several positive emotions other than happiness across cultures, but self-conscious emotions such as guilt, pride, and shame seem not to be well recognized from non-linguistic vocalizations. PMID:23914178

  14. Non-retinotopic feature processing in the absence of retinotopic spatial layout and the construction of perceptual space from motion.

    Science.gov (United States)

    Ağaoğlu, Mehmet N; Herzog, Michael H; Oğmen, Haluk

    2012-10-15

    The spatial representation of a visual scene in the early visual system is well known. The optics of the eye map the three-dimensional environment onto two-dimensional images on the retina. These retinotopic representations are preserved in the early visual system. Retinotopic representations and processing are among the most prevalent concepts in visual neuroscience. However, it has long been known that a retinotopic representation of the stimulus is neither sufficient nor necessary for perception. Saccadic Stimulus Presentation Paradigm and the Ternus-Pikler displays have been used to investigate non-retinotopic processes with and without eye movements, respectively. However, neither of these paradigms eliminates the retinotopic representation of the spatial layout of the stimulus. Here, we investigated how stimulus features are processed in the absence of a retinotopic layout and in the presence of retinotopic conflict. We used anorthoscopic viewing (slit viewing) and pitted a retinotopic feature-processing hypothesis against a non-retinotopic feature-processing hypothesis. Our results support the predictions of the non-retinotopic feature-processing hypothesis and demonstrate the ability of the visual system to operate non-retinotopically at a fine feature processing level in the absence of a retinotopic spatial layout. Our results suggest that perceptual space is actively constructed from the perceptual dimension of motion. The implications of these findings for normal ecological viewing conditions are discussed.

  15. The process of processing: exploring the validity of Neisser's perceptual cycle model with accounts from critical decision-making in the cockpit.

    Science.gov (United States)

    Plant, Katherine L; Stanton, Neville A

    2015-01-01

    The perceptual cycle model (PCM) has been widely applied in ergonomics research in domains including road, rail and aviation. The PCM assumes that information processing occurs in a cyclical manner drawing on top-down and bottom-up influences to produce perceptual exploration and actions. However, the validity of the model has not been addressed. This paper explores the construct validity of the PCM in the context of aeronautical decision-making. The critical decision method was used to interview 20 helicopter pilots about critical decision-making. The data were qualitatively analysed using an established coding scheme, and composite PCMs for incident phases were constructed. It was found that the PCM provided a mutually exclusive and exhaustive classification of the information-processing cycles for dealing with critical incidents. However, a counter-cycle was also discovered which has been attributed to skill-based behaviour, characteristic of experts. The practical applications and future research questions are discussed. Practitioner Summary: This paper explores whether information processing, when dealing with critical incidents, occurs in the manner anticipated by the perceptual cycle model. In addition to the traditional processing cycle, a reciprocal counter-cycle was found. This research can be utilised by those who use the model as an accident analysis framework.

  16. Action-Specific Influences on Perception and Post-Perceptual Processes: Present Controversies and Future Directions

    Science.gov (United States)

    Philbeck, John W.; Witt, Jessica K.

    2015-01-01

    The action-specific perception account holds that people perceive the environment in terms of their ability to act in it. In this view, for example, decreased ability to climb a hill due to fatigue makes the hill visually appear to be steeper. Though influential, this account has not been universally accepted, and in fact a heated controversy has emerged. The opposing view holds that action capability has little or no influence on perception. Heretofore, the debate has been quite polarized, with efforts largely being focused on supporting one view and dismantling the other. We argue here that polarized debate can impede scientific progress and that the search for similarities between two sides of a debate can sharpen the theoretical focus of both sides and illuminate important avenues for future research. In this paper, we present a synthetic review of this debate, drawing from the literatures of both approaches, to clarify both the surprising similarities and the core differences between them. We critically evaluate existing evidence, discuss possible mechanisms of action-specific effects, and make recommendations for future research. A primary focus of future work will involve not only the development of methods that guard against action-specific post-perceptual effects, but also development of concrete, well-constrained underlying mechanisms. The criteria for what constitutes acceptable control of post-perceptual effects and what constitutes an appropriately specific mechanism vary between approaches, and bridging this gap is a central challenge for future research. PMID:26501227

  17. The shifting appearance/disappearance of holographic images and the dynamic ontology of perceptual and cognitive processes

    Science.gov (United States)

    Boissonnet, Philippe

    2013-02-01

    The French philosopher M Merleau-Ponty captured the dynamic of perception with his idea of the intertwining of perceiver and perceived. Light is what links them. In the case of holographic images, not only is spatial and colour perception the pure product of light, but this light information is always in the process of self-construction with our eyes, according to our movements and the point of view adopted. According to the aesthetic reception of a work of art, Holographic images vary greatly from those of cinema, photography and even every kind of digital 3D animation. This particular image's status truly makes perceptually apparent the "co-emergence" of light and our gaze. But holography never misleads us with respect to the precarious nature of our perceptions. We have no illusion as to the limits of our empirical understanding of the perceived reality. Holography, like our knowledge of the visible, thus brings to light the phenomenon of reality's "co-constitution" and contributes to a dynamic ontology of perceptual and cognitive processes. The cognitivist Francico Varela defines this as the paradigm of enaction,i which I will adapt and apply to the appearance/disappearance context of holographic images to bring out their affinities on a metaphorical level.

  18. Population response to natural images in the primary visual cortex encodes local stimulus attributes and perceptual processing.

    Science.gov (United States)

    Ayzenshtat, Inbal; Gilad, Ariel; Zurawel, Guy; Slovin, Hamutal

    2012-10-01

    The primary visual cortex (V1) is extensively studied with a large repertoire of stimuli, yet little is known about its encoding of natural images. Using voltage-sensitive dye imaging in behaving monkeys, we measured neural population response evoked in V1 by natural images presented during a face/scramble discrimination task. The population response showed two distinct phases of activity: an early phase that was spread over most of the imaged area, and a late phase that was spatially confined. To study the detailed relation between the stimulus and the population response, we used a simple encoding model to compute a continuous map of the expected neural response based on local attributes of the stimulus (luminance and contrast), followed by an analytical retinotopic transformation. Then, we computed the spatial correlation between the maps of the expected and observed response. We found that the early response was highly correlated with the local luminance of the stimulus and was sufficient to effectively discriminate between stimuli at the single trial level. The late response, on the other hand, showed a much lower correlation to the local luminance, was confined to central parts of the face images, and was highly correlated with the animal's perceptual report. Our study reveals a continuous spatial encoding of low- and high-level features of natural images in V1. The low level is directly linked to the stimulus basic local attributes and the high level is correlated with the perceptual outcome of the stimulus processing.

  19. Infant auditory short-term memory for non-linguistic sounds.

    Science.gov (United States)

    Ross-Sheehy, Shannon; Newman, Rochelle S

    2015-04-01

    This research explores auditory short-term memory (STM) capacity for non-linguistic sounds in 10-month-old infants. Infants were presented with auditory streams composed of repeating sequences of either 2 or 4 unique instruments (e.g., flute, piano, cello; 350 or 700 ms in duration) followed by a 500-ms retention interval. These instrument sequences either stayed the same for every repetition (Constant) or changed by 1 instrument per sequence (Varying). Using the head-turn preference procedure, infant listening durations were recorded for each stream type (2- or 4-instrument sequences composed of 350- or 700-ms notes). Preference for the Varying stream was taken as evidence of auditory STM because detection of the novel instrument required memory for all of the instruments in a given sequence. Results demonstrate that infants listened longer to Varying streams for 2-instrument sequences, but not 4-instrument sequences, composed of 350-ms notes (Experiment 1), although this effect did not hold when note durations were increased to 700 ms (Experiment 2). Experiment 3 replicates and extends results from Experiments 1 and 2 and provides support for a duration account of capacity limits in infant auditory STM. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Simple perceptual color space for color specification and real-time processing

    Science.gov (United States)

    Kotsarenko, Yuriy; Ramos, Fernando

    2011-08-01

    In this work an alternative color space is described that defines the color elements in terms of approximated brightness, hue and saturation, similar to other color spaces commonly used in computer applications. The classical color spaces such as HSL and HSV in the form that is widely used are made for convenience, and do not model colors based on human perception. Other classical color spaces such as CIELAB, DIN99 and even more recent CIECAM-based color spaces are too cumbersome and difficult to work with. The proposed alternative, on the other hand, is simple to work with and has its "lightness" component tuned up to represent the perceived brightness closer to the reality. It is based on how luma is calculated in color spaces such as YUV and YIQ among others, but instead of using constant coefficients, it uses Euclidean distance formula with weighting coefficients. Several experiments are described that illustrate the proposed color space visualized in 3D and compared to other color spaces in perceptual terms and performance benchmarks. This is aided by a novel technique that allows normalizing the chroma of existing color spaces within a fixed interval. The experiments show that the proposed color space is a viable alternative for applications that already use HSV and HSL. A practical application is described, where the color space is used for 3D illumination with specular reflections running on dedicated graphics processor unit using shaders. This resolves visual defects present in the classical approaches that use RGB color space.

  1. Conflict-Induced Perceptual Filtering

    Science.gov (United States)

    Wendt, Mike; Luna-Rodriguez, Aquiles; Jacobsen, Thomas

    2012-01-01

    In a variety of conflict paradigms, target and distractor stimuli are defined in terms of perceptual features. Interference evoked by distractor stimuli tends to be reduced when the ratio of congruent to incongruent trials is decreased, suggesting conflict-induced perceptual filtering (i.e., adjusting the processing weights assigned to stimuli…

  2. Perceptual basis for reactive teleoperation.

    Energy Technology Data Exchange (ETDEWEB)

    Park, Y. S.; Ewing, T. F.; Boyle, J. M.; Yule, T. J.

    2001-08-28

    To enhance task performance in partially structured environment, enhancement of teleoperation was proposed by introducing autonomous behaviors. Such autonomy is implemented based on reactive robotic architecture, where reactive motor agents that directly couples sensory inputs and motor actions become the building blocks. To this end, presented in this paper is a perceptual basis for the motor agents. The perceptual basis consists of perceptual agents that extracts environmental information from a structured light vision system and provide action oriented perception for the corresponding motor agents. Rather than performing general scene reconstruction, a perceptual agent directly provides the motion reference for the motor behavior. Various sensory mechanisms--sensor fission, fusion, and fashion--becomes basic building blocks of the perception process. Since perception is a process deeply intertwined with the motor actions, active perception may also incorporate motor behaviors as an integral perceptual process.

  3. Genetic correlations between brain volumes and the WAIS-III dimensions of verbal comprehension, working memory, perceptual organization, and processing speed

    DEFF Research Database (Denmark)

    Posthuma, Daniëlle; Baare, Wim F.C.; Hulshoff Pol, Hilleke E.

    2003-01-01

    We recently showed that the correlation of gray and white matter volume with full scale IQ and the Working Memory dimension are completely mediated by common genetic factors (Posthuma et al., 2002). Here we examine whether the other WAIS III dimensions (Verbal Comprehension, Perceptual Organization...... to Working Memory capacity (r = 0.27). This phenotypic correlation is completely due to a common underlying genetic factor. Processing Speed was genetically related to white matter volume (r(g) = 0.39). Perceptual Organization was both genetically (r(g) = 0.39) and environmentally (r(e) = -0.71) related...

  4. Use what you can: storage, abstraction processes, and perceptual adjustments help listeners recognize reduced forms.

    Science.gov (United States)

    Poellmann, Katja; Mitterer, Holger; McQueen, James M

    2014-01-01

    Three eye-tracking experiments tested whether native listeners recognized reduced Dutch words better after having heard the same reduced words, or different reduced words of the same reduction type and whether familiarization with one reduction type helps listeners to deal with another reduction type. In the exposure phase, a segmental reduction group was exposed to /b/-reductions (e.g., minderij instead of binderij, "book binder") and a syllabic reduction group was exposed to full-vowel deletions (e.g., p'raat instead of paraat, "ready"), while a control group did not hear any reductions. In the test phase, all three groups heard the same speaker producing reduced-/b/ and deleted-vowel words that were either repeated (Experiments 1 and 2) or new (Experiment 3), but that now appeared as targets in semantically neutral sentences. Word-specific learning effects were found for vowel-deletions but not for /b/-reductions. Generalization of learning to new words of the same reduction type occurred only if the exposure words showed a phonologically consistent reduction pattern (/b/-reductions). In contrast, generalization of learning to words of another reduction type occurred only if the exposure words showed a phonologically inconsistent reduction pattern (the vowel deletions; learning about them generalized to recognition of the /b/-reductions). In order to deal with reductions, listeners thus use various means. They store reduced variants (e.g., for the inconsistent vowel-deleted words) and they abstract over incoming information to build up and apply mapping rules (e.g., for the consistent /b/-reductions). Experience with inconsistent pronunciations leads to greater perceptual flexibility in dealing with other forms of reduction uttered by the same speaker than experience with consistent pronunciations.

  5. Use what you can: Storage, abstraction processes and perceptual adjustments help listeners recognize reduced forms

    Directory of Open Access Journals (Sweden)

    Katja ePoellmann

    2014-05-01

    Full Text Available Three eye-tracking experiments tested whether native listeners recognized reduced Dutch words better after having heard the same reduced words, or different reduced words of the same reduction type and whether familiarization with one reduction type helps listeners to deal with another reduction type. In the exposure phase, a segmental reduction group was exposed to /b/-reductions (e.g., minderij instead of binderij, 'book binder' and a syllabic reduction group was exposed to full-vowel deletions (e.g., p'raat instead of paraat, 'ready', while a control group did not hear any reductions. In the test phase, all three groups heard the same speaker producing reduced-/b/ and deleted-vowel words that were either repeated (Experiments 1 & 2 or new (Experiment 3, but that now appeared as targets in semantically neutral sentences. Word-specific learning effects were found for vowel-deletions but not for /b/-reductions. Generalization of learning to new words of the same reduction type occurred only if the exposure words showed a phonologically consistent reduction pattern (/b/-reductions. In contrast, generalization of learning to words of another reduction type occurred only if the exposure words showed a phonologically inconsistent reduction pattern (the vowel deletions; learning about them generalized to recognition of the /b/-reductions. In order to deal with reductions, listeners thus use various means. They store reduced variants (e.g., for the inconsistent vowel-deleted words and they abstract over incoming information to build up and apply mapping rules (e.g., for the consistent /b/-reductions. Experience with inconsistent pronunciations leads to greater perceptual flexibility in dealing with other forms of reduction uttered by the same speaker than experience with consistent pronunciations.

  6. TYPOLOGIZATION OF SOCIO-CULTURAL EXERCISES FOR DEVELOPMENT OF AUDIO-VISIAL RECEPTION SKILLS OF NON-LINGUISTIC UNIVERSITY STUDENTS

    Directory of Open Access Journals (Sweden)

    Наталья Владимировна Базина

    2014-05-01

    Full Text Available The article describes principles of building a complex of socio-cultural exercises intended for the materials of German TV to be used in training students of non-linguistic universities with under-threshold level of German language skills. Besides that the types of German language exercises for the students of non-linguistic universities are given where students study German as second language in the context of socio-cultural and competence approach for preparation of international journalists on the Bachelor level. The author also has analyzed opportunity to use proposed types of exercises for improvement of professional competences of future international journalists by the means of German language in accordance with new state standards of professional education. Proposed system of exercises is intended for the classes of German language taught through German TV of Galileo series and was successfully tested in practice.DOI: http://dx.doi.org/10.12731/2218-7405-2014-2-17

  7. The relationship between linguistic and non-linguistic cognitive control skills in bilingual children from low socio-economic backgrounds

    Directory of Open Access Journals (Sweden)

    Milijana eBuac

    2014-09-01

    Full Text Available The present study examined whether linguistic cognitive control skills were related to non-linguistic cognitive control skills in monolingual children (Study 1 and in bilingual children from low socio-economic status (SES backgrounds (Study 2. Linguistic inhibitory control was measured using a grammaticality judgment (GJ task in which children judged the grammaticality of sentences while ignoring their meaning. Non-linguistic inhibitory control was measured using a flanker task. Study 1, in which we tested monolingual English-speaking children, revealed that better inhibitory control skills, as indexed by the performance on the flanker task, were associated with improved performance on the GJ task. Study 2, in which we tested bilingual English-Spanish speaking children from low SES backgrounds, revealed that better non-linguistic inhibitory control skills did not yield better performance on the GJ task. Together, these findings point to a role of domain-general attention mechanisms in language performance in typically developing monolingual children, but not in bilingual children from low SES. Present results suggest that the relationship between linguistic and domain-general cognitive-control abilities is instantiated differently in bilingual vs. monolingual children, and that language-EF interactions are sensitive to language status and SES.

  8. Perceptual expertise: can sensorimotor experience change holistic processing and left-side bias?

    Science.gov (United States)

    Tso, Ricky Van-yip; Au, Terry Kit-fong; Hsiao, Janet Hui-wen

    2014-09-01

    Holistic processing and left-side bias are both behavioral markers of expert face recognition. By contrast, expert recognition of characters in Chinese orthography involves left-side bias but reduced holistic processing, although faces and Chinese characters share many visual properties. Here, we examined whether this reduction in holistic processing of Chinese characters can be better explained by writing experience than by reading experience. Compared with Chinese nonreaders, Chinese readers who had limited writing experience showed increased holistic processing, whereas Chinese readers who could write characters fluently showed reduced holistic processing. This result suggests that writing and sensorimotor experience can modulate holistic-processing effects and that the reduced holistic processing observed in expert Chinese readers may depend mostly on writing experience. However, both expert writers and writers with limited experience showed similarly stronger left-side bias than novices did in processing mirror-symmetric Chinese characters; left-side bias may therefore be a robust expertise marker for object recognition that is uninfluenced by sensorimotor experience.

  9. Contextual and perceptual brain processes underlying moral cognition: a quantitative meta-analysis of moral reasoning and moral emotions.

    Directory of Open Access Journals (Sweden)

    Gunes Sevinc

    processing of moral input is affected by task demands. The results provide novel insight into distinct features of moral cognition, including the generation of moral context through associative processes and the perceptual detection of moral salience.

  10. Contextual and Perceptual Brain Processes Underlying Moral Cognition: A Quantitative Meta-Analysis of Moral Reasoning and Moral Emotions

    Science.gov (United States)

    Sevinc, Gunes; Spreng, R. Nathan

    2014-01-01

    moral input is affected by task demands. The results provide novel insight into distinct features of moral cognition, including the generation of moral context through associative processes and the perceptual detection of moral salience. PMID:24503959

  11. Contextual and perceptual brain processes underlying moral cognition: a quantitative meta-analysis of moral reasoning and moral emotions.

    Science.gov (United States)

    Sevinc, Gunes; Spreng, R Nathan

    2014-01-01

    insight into distinct features of moral cognition, including the generation of moral context through associative processes and the perceptual detection of moral salience.

  12. Processing the papal encyclical through perceptual filters: Pope Francis, identity-protective cognition, and climate change concern.

    Science.gov (United States)

    Landrum, Asheley R; Lull, Robert B; Akin, Heather; Hasell, Ariel; Jamieson, Kathleen Hall

    2017-09-01

    Previous research suggests that when individuals encounter new information, they interpret it through perceptual 'filters' of prior beliefs, relevant social identities, and messenger credibility. In short, evaluations are not based solely on message accuracy, but also on the extent to which the message and messenger are amenable to the values of one's social groups. Here, we use the release of Pope Francis's 2015 encyclical as the context for a natural experiment to examine the role of prior values in climate change cognition. Based on our analysis of panel data collected before and after the encyclical's release, we find that political ideology moderated views of papal credibility on climate change for those participants who were aware of the encyclical. We also find that, in some contexts, non-Catholics who were aware of the encyclical granted Pope Francis additional credibility compared to the non-Catholics who were unaware of it, yet Catholics granted the Pope high credibility regardless of encyclical awareness. Importantly, papal credibility mediated the conditional relationships between encyclical awareness and acceptance of the Pope's messages on climate change. We conclude by discussing how our results provide insight into cognitive processing of new information about controversial issues. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Facial identity and facial expression are initially integrated at visual perceptual stages of face processing.

    Science.gov (United States)

    Fisher, Katie; Towler, John; Eimer, Martin

    2016-01-08

    It is frequently assumed that facial identity and facial expression are analysed in functionally and anatomically distinct streams within the core visual face processing system. To investigate whether expression and identity interact during the visual processing of faces, we employed a sequential matching procedure where participants compared either the identity or the expression of two successively presented faces, and ignored the other irrelevant dimension. Repetitions versus changes of facial identity and expression were varied independently across trials, and event-related potentials (ERPs) were recorded during task performance. Irrelevant facial identity and irrelevant expression both interfered with performance in the expression and identity matching tasks. These symmetrical interference effects show that neither identity nor expression can be selectively ignored during face matching, and suggest that they are not processed independently. N250r components to identity repetitions that reflect identity matching mechanisms in face-selective visual cortex were delayed and attenuated when there was an expression change, demonstrating that facial expression interferes with visual identity matching. These findings provide new evidence for interactions between facial identity and expression within the core visual processing system, and question the hypothesis that these two attributes are processed independently.

  14. Perceptual Training Strongly Improves Visual Motion Perception in Schizophrenia

    Science.gov (United States)

    Norton, Daniel J.; McBain, Ryan K.; Ongur, Dost; Chen, Yue

    2011-01-01

    Schizophrenia patients exhibit perceptual and cognitive deficits, including in visual motion processing. Given that cognitive systems depend upon perceptual inputs, improving patients' perceptual abilities may be an effective means of cognitive intervention. In healthy people, motion perception can be enhanced through perceptual learning, but it…

  15. Perceptual Training Strongly Improves Visual Motion Perception in Schizophrenia

    Science.gov (United States)

    Norton, Daniel J.; McBain, Ryan K.; Ongur, Dost; Chen, Yue

    2011-01-01

    Schizophrenia patients exhibit perceptual and cognitive deficits, including in visual motion processing. Given that cognitive systems depend upon perceptual inputs, improving patients' perceptual abilities may be an effective means of cognitive intervention. In healthy people, motion perception can be enhanced through perceptual learning, but it…

  16. Computational models of music perception and cognition I: The perceptual and cognitive processing chain

    Science.gov (United States)

    Purwins, Hendrik; Herrera, Perfecto; Grachten, Maarten; Hazan, Amaury; Marxer, Ricard; Serra, Xavier

    2008-09-01

    We present a review on perception and cognition models designed for or applicable to music. An emphasis is put on computational implementations. We include findings from different disciplines: neuroscience, psychology, cognitive science, artificial intelligence, and musicology. The article summarizes the methodology that these disciplines use to approach the phenomena of music understanding, the localization of musical processes in the brain, and the flow of cognitive operations involved in turning physical signals into musical symbols, going from the transducers to the memory systems of the brain. We discuss formal models developed to emulate, explain and predict phenomena involved in early auditory processing, pitch processing, grouping, source separation, and music structure computation. We cover generic computational architectures of attention, memory, and expectation that can be instantiated and tuned to deal with specific musical phenomena. Criteria for the evaluation of such models are presented and discussed. Thereby, we lay out the general framework that provides the basis for the discussion of domain-specific music models in Part II.

  17. Passing faces: sequence-dependent variations in the perceptual processing of emotional faces.

    Science.gov (United States)

    Karl, Christian; Hewig, Johannes; Osinsky, Roman

    2016-10-01

    There is broad evidence that contextual factors influence the processing of emotional facial expressions. Yet temporal-dynamic aspects, inter alia how face processing is influenced by the specific order of neutral and emotional facial expressions, have been largely neglected. To shed light on this topic, we recorded electroencephalogram from 168 healthy participants while they performed a gender-discrimination task with angry and neutral faces. Our event-related potential (ERP) analyses revealed a strong emotional modulation of the N170 component, indicating that the basic visual encoding and emotional analysis of a facial stimulus happen, at least partially, in parallel. While the N170 and the late positive potential (LPP; 400-600 ms) were only modestly affected by the sequence of preceding faces, we observed a strong influence of face sequences on the early posterior negativity (EPN; 200-300 ms). Finally, the differing response patterns of the EPN and LPP indicate that these two ERPs represent distinct processes during face analysis: while the former seems to represent the integration of contextual information in the perception of a current face, the latter appears to represent the net emotional interpretation of a current face.

  18. Dual mechanisms in the perceptual processing of click train temporal regularity.

    Science.gov (United States)

    Phillips, Dennis P; Dingle, Rachel N; Hall, Susan E; Jang, Moragh

    2012-07-01

    Two experiments measured human sensitivity to temporal jitter in 25-click trains with inter-click intervals (ICIs) between 5 and 100 ms. In a naturalistic experiment using wideband clicks, jitter thresholds were a nonmonotonic function of ICI, peaking for ICIs near 40-60 ms. In a subsequent experiment, clicks were high-passed and presented against a low-frequency noise masker. Jitter threshold vs ICI functions lost the positive slope over short ICIs but retained the negative slope at long ICIs. The same behavior was seen in click rate discrimination tasks. Different processes mediate regularity analysis for click trains with ICIs above and below 40-60 ms.

  19. An analysis of the processing requirements of a complex perceptual-motor task

    Science.gov (United States)

    Kramer, A. F.; Wickens, C. D.; Donchin, E.

    1983-01-01

    Current concerns in the assessment of mental workload are discussed, and the event-related brain potential (ERP) is introduced as a promising mental-workload index. Subjects participated in a series of studies in which they were required to perform a target acquisition task while also covertly counting either auditory or visual probes. The effects of several task-difficulty manipulations on the P300 component of the ERP elicited by the counted stimulus probes were investigated. With sufficiently practiced subjects the amplitude of the P300 was found to decrease with increases in task difficulty. The second experiment also provided evidence that the P300 is selectively sensitive to task-relevant attributes. A third experiment demonstrated a convergence in the amplitude of the P300s elicited in the simple and difficult versions of the tracking task. The amplitude of the P300 was also found to covary with the measures of tracking performance. The results of the series of three experiments illustrate the sensitivity of the P300 to the processing requirements of a complex target acquisition task. The findings are discussed in terms of the multidimensional nature of processing resources.

  20. [Recent trends in the psychology of music perception: the perceptual processes of melody and musical pitch].

    Science.gov (United States)

    Tsuzaki, M

    1988-08-01

    In this article some of the recent researches on music perception are reviewed, with a special emphasis upon those that concern melody organization and musical pitch. Lerdahl and Jackendoff (1983) pointed out that there is a grammatical parallel between music and language, and presented some grammatical rules for the tonal music. Serafine (1983) cautioned us not to confuse the "style principles" with the "musical cognitive process". The recent experiments on musical pitch and melody has reinforced the psychological validity of musical segmentation, tonality, pitch chroma, scale, and key. Theoretical approaches to the relations in the scale systems gave the possibility of a "new scale system" for use in psychological experiments, while the recent pitch models has made it possible for us to control tonality and to generate tones never used before in playing music. The need for a greater cross-stylistic generality of psychological concepts in music and the farther clarification of the "musical cognitive process" through experiments utilizing the "new scale system" and the "new tones" are indicated.

  1. Predictability affects early perceptual processing of word onsets in continuous speech.

    Science.gov (United States)

    Astheimer, Lori B; Sanders, Lisa D

    2011-10-01

    Event-related potential (ERP) evidence indicates that listeners selectively attend to word onsets in continuous speech, but the reason for this preferential processing is unknown. The current study measured ERPs elicited by syllable onsets in an artificial language to test the hypothesis that listeners direct attention to word onsets because their identity is unpredictable. Both before and after recognition training, participants listened to a continuous stream of six nonsense words arranged in pairs, such that the second word in each pair was completely predictable. After training, first words in pairs elicited a larger negativity beginning around 100 ms after onset. This effect was not evident for the completely predictable second words in pairs. These results suggest that listeners are most likely to attend to the segments in speech that they are least able to predict.

  2. Altered attentional and perceptual processes as indexed by N170 during gaze perception in schizophrenia: Relationship with perceived threat and paranoid delusions.

    Science.gov (United States)

    Tso, Ivy F; Calwas, Anita M; Chun, Jinsoo; Mueller, Savanna A; Taylor, Stephan F; Deldin, Patricia J

    2015-08-01

    Using gaze information to orient attention and guide behavior is critical to social adaptation. Previous studies have suggested that abnormal gaze perception in schizophrenia (SCZ) may originate in abnormal early attentional and perceptual processes and may be related to paranoid symptoms. Using event-related brain potentials (ERPs), this study investigated altered early attentional and perceptual processes during gaze perception and their relationship to paranoid delusions in SCZ. Twenty-eight individuals with SCZ or schizoaffective disorder and 32 demographically matched healthy controls (HCs) completed a gaze-discrimination task with face stimuli varying in gaze direction (direct, averted), head orientation (forward, deviated), and emotion (neutral, fearful). ERPs were recorded during the task. Participants rated experienced threat from each face after the task. Participants with SCZ were as accurate as, though slower than, HCs on the task. Participants with SCZ displayed enlarged N170 responses over the left hemisphere to averted gaze presented in fearful relative to neutral faces, indicating a heightened encoding sensitivity to faces signaling external threat. This abnormality was correlated with increased perceived threat and paranoid delusions. Participants with SCZ also showed a reduction of N170 modulation by head orientation (normally increased amplitude to deviated faces relative to forward faces), suggesting less integration of contextual cues of head orientation in gaze perception. The psychophysiological deviations observed during gaze discrimination in SCZ underscore the role of early attentional and perceptual abnormalities in social information processing and paranoid symptoms of SCZ.

  3. Genetic correlations between brain volumes and the WAIS-III dimensions of verbal comprehension, working memory, perceptual organization, and processing speed

    DEFF Research Database (Denmark)

    Posthuma, Daniëlle; Baare, Wim F.C.; Hulshoff Pol, Hilleke E.;

    2003-01-01

    to cerebellar volume. Verbal Comprehension was not related to any of the three brain volumes. It is concluded that brain volumes are genetically related to intelligence which suggests that genes that influence brain volume may also be important for intelligence. It is also noted however, that the direction......We recently showed that the correlation of gray and white matter volume with full scale IQ and the Working Memory dimension are completely mediated by common genetic factors (Posthuma et al., 2002). Here we examine whether the other WAIS III dimensions (Verbal Comprehension, Perceptual Organization...... to Working Memory capacity (r = 0.27). This phenotypic correlation is completely due to a common underlying genetic factor. Processing Speed was genetically related to white matter volume (r(g) = 0.39). Perceptual Organization was both genetically (r(g) = 0.39) and environmentally (r(e) = -0.71) related...

  4. Specialization of Perceptual Processes.

    Science.gov (United States)

    1994-09-01

    memory. The memory is trained to associate proper actions with overhead views from a planar world. The system can return to a home position by...phrases) (let ((code (list (length phrases) name))) (dolist (phrase phrases) (let ((sym ( gensym )) (c (code-string phrase))) (setf code (nconc (list* (first...Science Applications International Corp., 1984. [81] Dean A. Pomerleau. Ecient training of arti cial neural networks for au- tonomous navigation. Neural

  5. Perceptual-binding and persistent surface segregation

    OpenAIRE

    2004-01-01

    Visual input is segregated in the brain into subsystems that process different attributes such as motion and color. At the same time, visual information is perceptually segregated into objects and surfaces. Here we demonstrate that perceptual segregation of visual entities based on a transparency cue precedes and affects perceptual binding of attributes. Adding an irrelevant transparency cue paradoxically improved the pairing of color and motion for rapidly alternating surfaces. Subsequent ex...

  6. Perceptual-binding and persistent surface segregation.

    Science.gov (United States)

    Moradi, Farshad; Shimojo, Shinsuke

    2004-11-01

    Visual input is segregated in the brain into subsystems that process different attributes such as motion and color. At the same time, visual information is perceptually segregated into objects and surfaces. Here we demonstrate that perceptual segregation of visual entities based on a transparency cue precedes and affects perceptual binding of attributes. Adding an irrelevant transparency cue paradoxically improved the pairing of color and motion for rapidly alternating surfaces. Subsequent experiments show: (1) Attributes are registered over the temporal window defined by the perceptual persistence of segregation, resulting in asynchrony in binding, and (2) attention is necessary for correct registration of attributes in the presence of ambiguity.

  7. Electrophysiological Correlates of Familiarity and Recollection in Associative Recognition: Contributions of Perceptual and Conceptual Processing to Unitization.

    Science.gov (United States)

    Li, Bingcan; Mao, Xinrui; Wang, Yujuan; Guo, Chunyan

    2017-01-01

    It is generally accepted that associative recognition memory is supported by recollection. In addition, recent research indicates that familiarity can support associative memory, especially when two items are unitized into a single item. Both perceptual and conceptual manipulations can be used to unitize items, but few studies have compared these two methods of unitization directly. In the present study, we investigated the effects of familiarity and recollection on successful retrieval of items that were unitized perceptually or conceptually. Participants were instructed to remember either a Chinese two-character compound or unrelated word-pairs, which were presented simultaneously or sequentially. Participants were then asked to recognize whether word-pairs were intact or rearranged. Event-related potential (ERP) recordings were performed during the recognition phase of the study. Two-character compounds were better discriminated than unrelated word-pairs and simultaneous presentation was found to elicit better discrimination than sequential presentation for unrelated word-pairs only. ERP recordings indicated that the early intact/rearranged effects (FN400), typically associated with familiarity, were elicited in compound word-pairs with both simultaneous and sequential presentation, and in simultaneously presented unrelated word-pairs, but not in sequentially presented unrelated word-pairs. In contrast, the late positive complex (LPC) effects associated with recollection were elicited in all four conditions. Together, these results indicate that while the engagement of familiarity in associative recognition is affected by both perceptual and conceptual unitization, conceptual unitization promotes a higher level of unitization (LOU). In addition, the engagement of recollection was not affected by unitized manipulations. It should be noted, however, that due to experimental design, the effects presented here may be due to semantic rather than episodic memory and

  8. Perceptual learning: top to bottom.

    Science.gov (United States)

    Amitay, Sygal; Zhang, Yu-Xuan; Jones, Pete R; Moore, David R

    2014-06-01

    Perceptual learning has traditionally been portrayed as a bottom-up phenomenon that improves encoding or decoding of the trained stimulus. Cognitive skills such as attention and memory are thought to drive, guide and modulate learning but are, with notable exceptions, not generally considered to undergo changes themselves as a result of training with simple perceptual tasks. Moreover, shifts in threshold are interpreted as shifts in perceptual sensitivity, with no consideration for non-sensory factors (such as response bias) that may contribute to these changes. Accumulating evidence from our own research and others shows that perceptual learning is a conglomeration of effects, with training-induced changes ranging from the lowest (noise reduction in the phase locking of auditory signals) to the highest (working memory capacity) level of processing, and includes contributions from non-sensory factors that affect decision making even on a "simple" auditory task such as frequency discrimination. We discuss our emerging view of learning as a process that increases the signal-to-noise ratio associated with perceptual tasks by tackling noise sources and inefficiencies that cause performance bottlenecks, and present some implications for training populations other than young, smart, attentive and highly-motivated college students.

  9. Continuity and Discontinuity of Perceptual Development.

    Science.gov (United States)

    Fischer, Hardi

    Despite external changes such as those of magnitudes, the functional properties of the visual system also improve with increased age. According to Jean Piaget's centration/decentration theory, the process of perceptual development might continue until adulthood and even after. However, perceptual development should not be understood in all of its…

  10. Perceptual Fusion in Humans and Machines

    NARCIS (Netherlands)

    Salah, A.A.; Tanrı dağ , O.

    2008-01-01

    Humans perceive the world through different perceptual modalities, which are processed in the brain by modality-specific areas and structures. However, there also exist multimodal neurons and areas, specialized in integrating perceptual information to enhance or suppress brain response. The particu

  11. Thresholds of visibility for masked lexical, non-lexical, and non-linguistic items in aphasia

    OpenAIRE

    2015-01-01

    Introduction Visual masking of primes is a method used to tap into automatic processing while reducing or eliminating conscious processing of the primes. Masking is achieved by presenting primes very rapidly and preceding and/or following them with additional visual stimuli that interfere with conscious processing of the primes (Greenwald, Klinger & Liu, 1989; Forster, Mohan & Hector, 2003). A recent series of studies using masked priming with aphasia (Silkes, Dierkes & Kendall, 2012;...

  12. Perceptual Repetition Blindness Effects

    Science.gov (United States)

    Hochhaus, Larry; Johnston, James C.; Null, Cynthia H. (Technical Monitor)

    1994-01-01

    The phenomenon of repetition blindness (RB) may reveal a new limitation on human perceptual processing. Recently, however, researchers have attributed RB to post-perceptual processes such as memory retrieval and/or reporting biases. The standard rapid serial visual presentation (RSVP) paradigm used in most RB studies is, indeed, open to such objections. Here we investigate RB using a "single-frame" paradigm introduced by Johnston and Hale (1984) in which memory demands are minimal. Subjects made only a single judgement about whether one masked target word was the same or different than a post-target probe. Confidence ratings permitted use of signal detection methods to assess sensitivity and bias effects. In the critical condition for RB a precue of the post-target word was provided prior to the target stimulus (identity precue), so that the required judgement amounted to whether the target did or did not repeat the precue word. In control treatments, the precue was either an unrelated word or a dummy.

  13. MUSIC IN E-LEARNING COURSES OF THE ENGLISH LANGUAGE AT NON-LINGUISTIC UNIVERSITIES

    Directory of Open Access Journals (Sweden)

    M. V. ARHIPOVA

    2015-01-01

    Full Text Available The article is written within the framework of the extended scientific research devoted to the music-semeiotic concept of developing students’ creative learning of foreign languages. The concept implies experimental study of psychological impact of music on the efficiency of the learning processes, on the development of general and specific abilities of students, in particular creative abilities to learn foreign languages. Solution of this task is based on the hypothesis of psychological integrity and interaction of musical and foreign language learning skills, which was confirmed by the researches of Professor Ryzhov scientific school. Experimental verification of the concept supposes organization of experimental teaching of foreign languages using the diversity of music. The aim of the article is to study the impact of music on students’ learning processes. The article suggests the original e-learning course “The Beatles Epoch in the UK Culture” on Moodle platform; the course is designed basically for self-study. The course provides the opportunity to check the self-studied material in class, enhancing additionally the acquired knowledge and making more efficient the English language learning process.

  14. Unifying Perceptual Learning

    Directory of Open Access Journals (Sweden)

    Philip J. Kellman

    2011-05-01

    Full Text Available What is the relation between perceptual learning (PL in basic sensory discriminations and in more complex tasks, including real-world learning tasks? Most recent PL work focuses on the former, using simple sensory dimensions and a few specific stimulus values. In contrast, other PL research and virtually all real-world tasks involve discovery of invariance amidst variation, and may also involve PL working synergistically with other cognitive abilities. In this talk I will suggest that, despite superficial differences, low- and high-level PL tasks draw upon—and reveal—a unified type of learning. I will consider several arguments that have been advanced in favor of confining perceptual learning to plasticity at the earliest cortical levels along with models of PL based on receptive field change vs. selection. These analyses do not support the idea of a separate low-level process but do support both the abstract character of PL and its dependence on unifying notions of discovery and selection. In the final part of the talk, I will relate this unified view of PL to direct practical applications. Learning technology based on PL modules (PLMs can address elusive aspects of learning, including pattern recognition, transfer, and fluency, even in high-level, symbolic domains, such as mathematics learning.

  15. FRAS1-related extracellular matrix 3 (FREM3 single-nucleotide polymorphism effects on gene expression, amygdala reactivity and perceptual processing speed

    Directory of Open Access Journals (Sweden)

    Yuliya eNikolova

    2015-09-01

    Full Text Available The A allele of the Fras1-related extracellular matrix protein 3 (FREM3 rs7676614 single nucleotide polymorphism (SNP was linked to major depressive disorder (MDD in an early genome-wide association study (GWAS, and to symptoms of psychomotor retardation in a follow-up investigation. In line with significant overlap between age- and depression-related molecular pathways, parallel work has shown that FREM3 expression in postmortem human brain decreases with age. Here we probe the effect of rs7676614 on amygdala reactivity and perceptual processing speed, both of which are altered in depression and aging. Amygdala reactivity was assessed using a face-matching BOLD fMRI paradigm in 365 Caucasian participants in the Duke Neurogenetics Study (192 women, mean age 19.7±1.2. Perceptual processing speed was indexed by reaction times in the same task and the Trails Making Test (TMT. The effect of rs7676614 on FREM3 mRNA brain expression levels was probed in a postmortem cohort of 169 Caucasian individuals (44 women, mean age 50.8±14.9. The A allele of rs7676614 was associated with blunted amygdala reactivity to faces, slower reaction times in the face-matching condition (p<0.04, as well as marginally slower performance on TMT Part B (p=0.056. In the postmortem cohort, the T allele of rs6537170 (proxy for the rs7676614 A allele, was associated with trend-level reductions in gene expression in Brodmann areas 11 and 47 (p=0.066, reminiscent of patterns characteristic of older age. The low-expressing allele of another FREM3 SNP (rs1391187 was similarly associated with reduced amygdala reactivity and slower TMT Part B speed, in addition to reduced BA47 activity and Extraversion (p<0.05. Together, these results suggest common genetic variation associated with reduced FREM3 expression may confer risk for a subtype of depression characterized by reduced reactivity to environmental stimuli and slower perceptual processing speed, possibly suggestive of

  16. Priorities of Dialogic Speech Teaching Methodology at Higher Non-Linguistic School

    Directory of Open Access Journals (Sweden)

    Vida Asanavičienė

    2011-04-01

    Full Text Available The article deals with a number of relevant methodological issues. First of all, the author analyses psychological peculiarities of dialogic speech and states that the dialogue is the product of at least two persons. Therefore, in this view, dialogic speech, unlike monologic speech, happens impromptu and is not prepared in advance. Dialogic speech is mainly of situational character. The linguistic nature of dialogic speech, in the author’s opinion, lies in the process of exchanging replications, which are coherent in structural and functional character. The author classifies dialogue groups by the number of replications and communicative parameters. The basic goal of dialogic speech teaching is developing the abilities and skills which enable to exchange replications. The author distinguishes two basic stages of dialogic speech teaching: 1. Training of abilities to exchange replications during communicative exercises. 2. Development of skills by training the capability to perform exercises of creative nature during a group dialogue, conversation or debate.

  17. PERCEPTUAL UNCONSCIOUS PROCESSING OF THE BRAIN%脑的感知觉无意识加工及其研究进展

    Institute of Scientific and Technical Information of China (English)

    柯学; 隋南; 沈德立

    2001-01-01

    该文从无意识加工与认知、脑结构、神经网络的关系等三个层面,阐述了近年来认知神经科学在无意识研究方面的进展。主要就无意识与意识的相互转化、无意识加工与认知层次、脑结构之间的关联性、突触的联结方式等问题进行了讨论,并对认知神经科学如何研究无意识与意识问题提出展望。%Consciousness has become a challenging question in life sciences. The viewpoint that consciousness is the processing of information at various levels of awareness is being widely accepted. It is inevitable to deal with unconscious or automatic processing for explicating consciousness. The main concern is how consciousness is converted into unconsciousness, how unconsciousness is done into consciousness, and the potential brain mechanisms of the conversion, including involvements of anatomical and functional structure, synaptic connections in the neural networks and so on. The study of unconsciousness is of great benefit to untie the mystery of consciousness that has been coming into focus by contemporary neuroscience. Recent progress of the study on the mechanisms of unconscious processing was reviewed from the points of cognitive neuroscience at different levels: the cognitive profile of unconsciousness, the correlation between unconsciousness and brain structures, and the interplay of synaptic connections. Contemporary research in cognitive psychology revealed that unconscious processing could even reach semantic level, including unconscious processing of image, character and figure. In addition, unconscious processing was different from conscious processing in nature and was distributed widely across the processing system of the brain, rather than localized in any particular unit. Recently, cognitive neuroscience has got lots of findings on perceptual unconscious processing with functional magnetic resonance imaging (fMRI), positron emission tomography (PET

  18. Rehabilitation of face-processing skills in an adolescent with prosopagnosia: Evaluation of an online perceptual training programme.

    Science.gov (United States)

    Bate, Sarah; Bennetts, Rachel; Mole, Joseph A; Ainge, James A; Gregory, Nicola J; Bobak, Anna K; Bussunt, Amanda

    2015-01-01

    In this paper we describe the case of EM, a female adolescent who acquired prosopagnosia following encephalitis at the age of eight. Initial neuropsychological and eye-movement investigations indicated that EM had profound difficulties in face perception as well as face recognition. EM underwent 14 weeks of perceptual training in an online programme that attempted to improve her ability to make fine-grained discriminations between faces. Following training, EM's face perception skills had improved, and the effect generalised to untrained faces. Eye-movement analyses also indicated that EM spent more time viewing the inner facial features post-training. Examination of EM's face recognition skills revealed an improvement in her recognition of personally-known faces when presented in a laboratory-based test, although the same gains were not noted in her everyday experiences with these faces. In addition, EM did not improve on a test assessing the recognition of newly encoded faces. One month after training, EM had maintained the improvement on the eye-tracking test, and to a lesser extent, her performance on the familiar faces test. This pattern of findings is interpreted as promising evidence that the programme can improve face perception skills, and with some adjustments, may at least partially improve face recognition skills.

  19. Negative BOLD response and serotonin concentration within rostral subgenual portion of the anterior cingulate cortex for long-allele carriers during perceptual processing of emotional tasks

    Science.gov (United States)

    Hadi, Shamil M.; Siadat, Mohamad R.; Babajani-Feremi, Abbas

    2012-03-01

    We investigated the effect of synaptic serotonin concentration on hemodynamic responses. The stimuli paradigm involved the presentation of fearful and threatening facial expressions to a set of 24 subjects who were either5HTTLPR long- or short-allele carriers (12 of each type in each group). The BOLD signals of the rACC from subjects of each group were averaged to increase the signal-to-noise ratio. We used a Bayesian approach to estimate the parameters of the underlying hemodynamic model. Our results, during this perceptual processing of emotional task, showed a negative BOLD signal in the rACC in the subjects with long-alleles. In contrast, the subjects with short-alleles showed positive BOLD signals in the rACC. These results suggest that high synaptic serotonin concentration in the rACC inhibits neuronal activity in a fashion similar to GABA, and a consequent negative BOLD signal ensues.

  20. Delayed perceptual awareness in rapid perceptual decisions.

    Directory of Open Access Journals (Sweden)

    Regina Gregori-Grgič

    Full Text Available The flourishing of studies on the neural correlates of decision-making calls for an appraisal of the relation between perceptual decisions and conscious perception. By exploiting the long integration time of noisy motion stimuli, and by forcing human observers to make difficult speeded decisions--sometimes a blind guess--about stimulus direction, we traced the temporal buildup of motion discrimination capability and perceptual awareness, as assessed trial by trial through direct rating. We found that both increased gradually with motion coherence and viewing time, but discrimination was systematically leading awareness, reaching a plateau much earlier. Sensitivity and criterion changes contributed jointly to the slow buildup of perceptual awareness. It made no difference whether motion discrimination was accomplished by saccades or verbal responses. These findings suggest that perceptual awareness emerges on the top of a developing or even mature perceptual decision. We argue that the middle temporal (MT cortical region does not confer us the full phenomenic depth of motion perception, although it may represent a precursor stage in building our subjective sense of visual motion.

  1. Effect of practice on perceptual load

    OpenAIRE

    Mejia-Ramirez, Manuel

    2013-01-01

    Within attention studies, Lavie's load theory (Lavie & Tsal, 1994; Lavie, Hirst, de Fockert, & Viding, 2004) presented an account that could settle the question whether attention selects stimuli to be processed at an early or late stage of cognitive processing. This theory relied on the concepts of "perceptual load" and "attentional capacity", proposing that attentional resources are automatically allocated to stimuli, but when the perceptual load of the stimuli exceeds person's capacity, tas...

  2. Early sensory-perceptual processing deficits for affectively valenced inputs are more pronounced in schizophrenia patients with a history of violence than in their non-violent peers.

    Science.gov (United States)

    De Sanctis, Pierfilippo; Foxe, John J; Czobor, Pal; Wylie, Glenn R; Kamiel, Stephanie M; Huening, Jessica; Nair-Collins, Mike; Krakowski, Menahem I

    2013-08-01

    Individuals with schizophrenia are more prone to violent behaviors than the general population. It is increasingly recognized that processing of emotionally valenced stimuli is impaired in schizophrenia, a deficit that may play a role in aggressive behavior. Our goal was to establish whether patients with a history of violence would show more severe deficits in processing emotionally valenced inputs than non-violent patients. Using event-related potentials, we measured how early during processing of emotional valence, evidence of aberrant function was observed. A total of 42 schizophrenia patients (21 with history of violence; 21 without) and 28 healthy controls were tested. Participants performed an inhibitory control task, making speeded responses to pictorial stimuli. Pictures occasionally repeated twice and participants withheld responses to these repeats. Valenced pictures from the International Affective Picture System were presented. Results in controls showed modulations during the earliest phases of sensory processing (schizophrenia group showed early differentiation. Non-violent patients showed earliest modulations beginning ∼150 ms. For violent patients, however, earliest modulations were further delayed and highly attenuated. The current study reveals sensory-perceptual processing dysfunction for negatively valenced inputs, which is particularly pronounced in aggressive patients.

  3. Motion transparency promotes synchronous perceptual binding.

    Science.gov (United States)

    Clifford, Colin W G; Spehar, Branka; Pearson, Joel

    2004-12-01

    While identified regions of human extrastriate visual cortex are functionally specialized for processing different attributes of an object, the cognitive and neural mechanisms by which these attributes are dynamically bound into integrated percepts are still largely mysterious. Here, we report that perceptual organization influences the dynamics of binding. Specifically, the perception of motion transparency promotes the synchronous perceptual binding of colour and motion, which otherwise exhibits considerable asynchronies. In addition, we demonstrate that perceptual asynchrony can be reinstated by manipulating stereoscopic disparity or speed within the stimulus. Our findings suggest that the phenomenology of colour-motion binding parallels the known physiology of motion processing in area MT of primate visual cortex, supporting the view that the dynamics of perceptual binding is a direct reflection of the time course of the underlying neural processing.

  4. Perceptual centering of body segment orientation.

    Science.gov (United States)

    Hanes, Douglas A

    2007-01-01

    It has been shown experimentally that under certain combinations of sensory stimuli, human subjects can perceive one of several distinct illusions about their overall orientation in or movement through space. In at least some cases, the structure of such multistable illusory perceptions of orientation can be efficiently described by perceptual transformations that act on a current orientation estimate to yield an updated perceptual construct. Repeated application of identified generating transformations yields a limited set of predicted illusions for a given sensory environment. This approach is especially valuable for perceptual data that exhibits discretely differing classes of illusions between subjects or trials. In a previous study, application of a semigroup of perceptual centering transformations has succeeded in reproducing and simplifying data from an experiment in which subjects experiencing visual vection reported a range of illusions about the orientations of their gaze, head, and torso to gravity. After reviewing previously obtained results on perceptual centering, this article generalizes the approach, presenting the mathematics required to characterize perceptual transformations. The developed framework should be widely applicable in the understanding of perceptual illusions, particularly when these are guided by alignment with preferred constructs. Secondly, the article reveals the nontrivial mathematical process of perceptual semigroup formation and evaluation, deducing the complete description of the semigroup constructed in the previous study. Perceptual centering transformations identified in terrestrial experiments may predict illusions to be expected in spaceflight. For example, our results indicate that under certain conditions, many astronauts will misperceive a visual rotation axis to be centered in front of the head or even the torso.

  5. How Much Does WAIS-IV Perceptual Reasoning Decline Across the 20 to 90-Year Lifespan When Processing Speed is Controlled?

    Science.gov (United States)

    Scheiber, Caroline; Chen, Hsinyi; Kaufman, Alan S; Weiss, Lawrence G

    2017-01-01

    The most prominent pattern of cognitive change over the lifespan centers on the difference between patterns of maintained abilities on tests of crystallized knowledge and patterns of steady decline on tests of problem solving and processing speed. Whereas the maintained-vulnerable dichotomy is well established in the literature, questions remain about cognitive decline in problem solving when processing speed is controlled. This relationship has been examined in cross-sectional studies that typically used non-clinical tests with non-representative samples of adults. This study extended these findings to the most popular clinical test, the Wechsler Adult Intelligence Scale -4th ed. (WAIS-IV), using its carefully stratified sample as the source of data (ages 20-90 for Indexes, ages 16-90 for Perceptual Reasoning subtests). Multivariate Analysis of Covariance (MANCOVA) revealed that 70-80% of the variance in declining reasoning ability was shared with the speed factor. This was true (a) on the index and subtest level and (b) regardless of the type of problem-solving task employed. Such robust findings have important clinical and research implications for neuropsychologists, who most frequently use the Wechsler scales as part of their assessment battery.

  6. THE PERCEPTUAL COGNITIVE PROCESSES UNDERPINNING SKILLED PERFORMANCE IN VOLLEYBALL: EVIDENCE FROM EYE-MOVEMENTS AND VERBAL REPORTS OF THINKING INVOLVING AN IN SITU REPRESENTATIVE TASK

    Directory of Open Access Journals (Sweden)

    José Afonso

    2012-06-01

    Full Text Available An extensive body of work has focused on the processes underpinning perceptual-cognitive expertise. The majority of researchers have used film-based simulations to capture superior performance. We combined eye movement recording and verbal reports of thinking to explore the processes underpinning skilled performance in a complex, dynamic, and externally paced representative volleyball task involving in situ data collection. Altogether, 27 female volleyball players performed as centre backcourt defenders in simulated sessions while wearing an eye-tracking device. After each sequence, athletes were questioned concerning their perception of the situation. The visual search strategies employed by the highly-skilled players were more exploratory than those used by skilled players, involving more fixations to a greater number of locations. Highly-skilled participants spent more time fixating on functional spaces between two or more display areas, while the skilled participants fixated on the ball trajectory and specific players. Moreover, highly-skilled players generated more condition concepts with higher levels of sophistication than their skilled counterparts. Findings highlight the value of using representative task designs to capture performance in situ

  7. Transfer-Appropriate Processing in Recognition Memory: Perceptual and Conceptual Effects on Recognition Memory Depend on Task Demands

    Science.gov (United States)

    Parks, Colleen M.

    2013-01-01

    Research examining the importance of surface-level information to familiarity in recognition memory tasks is mixed: Sometimes it affects recognition and sometimes it does not. One potential explanation of the inconsistent findings comes from the ideas of dual process theory of recognition and the transfer-appropriate processing framework, which…

  8. Relations between perceptual measures of temporal processing, auditory-evoked brainstem responses and speech intelligibility in noise

    DEFF Research Database (Denmark)

    Papakonstantinou, Alexandra; Strelcyk, Olaf; Dau, Torsten

    2011-01-01

    for the chirp-evoked ABRs indicated a relation to SRTs and the ability to process temporal fine structure. Overall, the results demonstrate the importance of low-frequency temporal processing for speech reception which can be affected even if pure-tone sensitivity is close to normal....

  9. Relations between perceptual and conceptual scope: how global versus local processing fits a focus on similarity versus dissimilarity

    NARCIS (Netherlands)

    Förster, J.

    2009-01-01

    Nine studies showed a bidirectional link (a) between a global processing style and generation of similarities and (b) between a local processing style and generation of dissimilarities. In Experiments 1-4, participants were primed with global versus local perception styles and then asked to work on

  10. Perceptual incongruence influences bistability and cortical activation.

    Directory of Open Access Journals (Sweden)

    Gijs Joost Brouwer

    Full Text Available We employed a parametric psychophysical design in combination with functional imaging to examine the influence of metric changes in perceptual incongruence on perceptual alternation rates and cortical responses. Subjects viewed a bistable stimulus defined by incongruent depth cues; bistability resulted from incongruence between binocular disparity and monocular perspective cues that specify different slants (slant rivalry. Psychophysical results revealed that perceptual alternation rates were positively correlated with the degree of perceived incongruence. Functional imaging revealed systematic increases in activity that paralleled the psychophysical results within anterior intraparietal sulcus, prior to the onset of perceptual alternations. We suggest that this cortical activity predicts the frequency of subsequent alternations, implying a putative causal role for these areas in initiating bistable perception. In contrast, areas implicated in form and depth processing (LOC and V3A were sensitive to the degree of slant, but failed to show increases in activity when these cues were in conflict.

  11. Perceptual Color Characterization of Cameras

    Directory of Open Access Journals (Sweden)

    Javier Vazquez-Corral

    2014-12-01

    Full Text Available Color camera characterization, mapping outputs from the camera sensors to an independent color space, such as \\(XYZ\\, is an important step in the camera processing pipeline. Until now, this procedure has been primarily solved by using a \\(3 \\times 3\\ matrix obtained via a least-squares optimization. In this paper, we propose to use the spherical sampling method, recently published by Finlayson al., to perform a perceptual color characterization. In particular, we search for the \\(3 \\times 3\\ matrix that minimizes three different perceptual errors, one pixel based and two spatially based. For the pixel-based case, we minimize the CIE \\(\\Delta E\\ error, while for the spatial-based case, we minimize both the S-CIELAB error and the CID error measure. Our results demonstrate an improvement of approximately 3for the \\(\\Delta E\\ error, 7& for the S-CIELAB error and 13% for the CID error measures.

  12. How perceptual processes help to generate new meaning: An EEG study of chunk decomposition in Chinese characters

    NARCIS (Netherlands)

    Wu, L.L.; Knoblich, G.K.; Wei, G.X.; Luo, J.

    2009-01-01

    Chunk decomposition has been regarded as an important process in problem solving that helps problem solvers to generate new solution paths through changing inappropriate problem representations. We studied the neural bases of chunk decomposition in Chinese characters using the electroencephalogram

  13. Language in Web Communication: A Crash Course - How to raise the linguistic awareness of non-linguist professionals in the workplace

    Directory of Open Access Journals (Sweden)

    Birthe Toft

    2012-08-01

    Full Text Available Having taught and carried out research in LSP and business communication for many years, I have come across, again and again, the problems arising from the inferior status of language in the business environment. Being convinced that it does not have to be so, instead of going on trying to convince non-linguistically trained colleagues of the importance of language via the usual arguments, I suggest that we let them experience the problems arising from the non-recognition of the importance of language via a Web communication crash course, inspired by a course taught to BA students at the University of Southern Denmark, Kolding.

  14. Generalization of multisensory perceptual learning

    Science.gov (United States)

    Powers III, Albert R.; Hillock-Dunn, Andrea; Wallace, Mark T.

    2016-01-01

    Life in a multisensory world requires the rapid and accurate integration of stimuli across the different senses. In this process, the temporal relationship between stimuli is critical in determining which stimuli share a common origin. Numerous studies have described a multisensory temporal binding window—the time window within which audiovisual stimuli are likely to be perceptually bound. In addition to characterizing this window’s size, recent work has shown it to be malleable, with the capacity for substantial narrowing following perceptual training. However, the generalization of these effects to other measures of perception is not known. This question was examined by characterizing the ability of training on a simultaneity judgment task to influence perception of the temporally-dependent sound-induced flash illusion (SIFI). Results do not demonstrate a change in performance on the SIFI itself following training. However, data do show an improved ability to discriminate rapidly-presented two-flash control conditions following training. Effects were specific to training and scaled with the degree of temporal window narrowing exhibited. Results do not support generalization of multisensory perceptual learning to other multisensory tasks. However, results do show that training results in improvements in visual temporal acuity, suggesting a generalization effect of multisensory training on unisensory abilities. PMID:27000988

  15. Perceptually-Inspired Computing

    Directory of Open Access Journals (Sweden)

    Ming Lin

    2015-08-01

    Full Text Available Human sensory systems allow individuals to see, hear, touch, and interact with the surrounding physical environment. Understanding human perception and its limit enables us to better exploit the psychophysics of human perceptual systems to design more efficient, adaptive algorithms and develop perceptually-inspired computational models. In this talk, I will survey some of recent efforts on perceptually-inspired computing with applications to crowd simulation and multimodal interaction. In particular, I will present data-driven personality modeling based on the results of user studies, example-guided physics-based sound synthesis using auditory perception, as well as perceptually-inspired simplification for multimodal interaction. These perceptually guided principles can be used to accelerating multi-modal interaction and visual computing, thereby creating more natural human-computer interaction and providing more immersive experiences. I will also present their use in interactive applications for entertainment, such as video games, computer animation, and shared social experience. I will conclude by discussing possible future research directions.

  16. Perceptual grouping in pigeons.

    Science.gov (United States)

    Nagasaka, Yasuo; Hori, Koji; Osada, Yoshihisa

    2005-01-01

    Animal studies reveal that many species perceive partially occluded objects in the same way as do humans. Pigeons have been a notable exception. We re-investigated this anomaly of pigeon perception using a different approach from previous studies. With our method, we show that pigeons perceive occluded objects in the same manner as do other species. In addition, we report that pigeons can recognize perceptually transparent surfaces when the effect is induced by the same perceptual mechanisms as occlusion. These results give behavioral evidence that the perception of both occlusion and transparency is a common visual function shared by pigeons and humans, despite the structural differences between their visual systems.

  17. Fusion of perceptions for perceptual robotics

    NARCIS (Netherlands)

    Ciftcioglu, O.; Bittermann, M.S.; Sariyildiz, I.S.

    2006-01-01

    Fusion of perception information for perceptual robotics is described. The visual perception is mathematically modelled as a probabilistic process obtaining and interpreting visual data from an environment. The visual data is processed in a multiresolutional form via wavelet transform and optimally

  18. Multisensory perceptual learning and sensory substitution.

    Science.gov (United States)

    Proulx, Michael J; Brown, David J; Pasqualotto, Achille; Meijer, Peter

    2014-04-01

    One of the most exciting recent findings in neuroscience has been the capacity for neural plasticity in adult humans and animals. Studies of perceptual learning have provided key insights into the mechanisms of neural plasticity and the changes in functional neuroanatomy that it affords. Key questions in this field of research concern how practice of a task leads to specific or general improvement. Although much of this work has been carried out with a focus on a single sensory modality, primarily visual, there is increasing interest in multisensory perceptual learning. Here we will examine how advances in perceptual learning research both inform and can be informed by the development and advancement of sensory substitution devices for blind persons. To allow 'sight' to occur in the absence of visual input through the eyes, visual information can be transformed by a sensory substitution device into a representation that can be processed as sound or touch, and thus give one the potential to 'see' through the ears or tongue. Investigations of auditory, visual and multisensory perceptual learning can have key benefits for the advancement of sensory substitution, and the study of sensory deprivation and sensory substitution likewise will further the understanding of perceptual learning in general and the reverse hierarchy theory in particular. It also has significant importance for the developing understanding of the brain in metamodal terms, where functional brain areas might be best defined by the computations they carry out rather than by their sensory-specific processing role.

  19. Frequent video game players resist perceptual interference.

    Directory of Open Access Journals (Sweden)

    Aaron V Berard

    Full Text Available Playing certain types of video games for a long time can improve a wide range of mental processes, from visual acuity to cognitive control. Frequent gamers have also displayed generalized improvements in perceptual learning. In the Texture Discrimination Task (TDT, a widely used perceptual learning paradigm, participants report the orientation of a target embedded in a field of lines and demonstrate robust over-night improvement. However, changing the orientation of the background lines midway through TDT training interferes with overnight improvements in overall performance on TDT. Interestingly, prior research has suggested that this effect will not occur if a one-hour break is allowed in between the changes. These results have suggested that after training is over, it may take some time for learning to become stabilized and resilient against interference. Here, we tested whether frequent gamers have faster stabilization of perceptual learning compared to non-gamers and examined the effect of daily video game playing on interference of training of TDT with one background orientation on perceptual learning of TDT with a different background orientation. As a result, we found that non-gamers showed overnight performance improvement only on one background orientation, replicating previous results with the interference in TDT. In contrast, frequent gamers demonstrated overnight improvements in performance with both background orientations, suggesting that they are better able to overcome interference in perceptual learning. This resistance to interference suggests that video game playing not only enhances the amplitude and speed of perceptual learning but also leads to faster and/or more robust stabilization of perceptual learning.

  20. Non-Linguistic Factors in English Reading Barriers%英语阅读理解障碍中的非语言因素

    Institute of Scientific and Technical Information of China (English)

    蒲云玲

    2007-01-01

    英语阅读是获得知识的一个重要方式,但是目前非英语专业大学生在英语阅读方面存在一些语言因素和非语言因素的障碍.本文通过对惠州学院二百名大学二年级的学生进行问卷调查,发现影响他们阅读的主要因素不是语言本身的问题,而是非语言因素,如背景知识、文化差异、阅读技巧、心理因素、思维模式等.本文着重研究和分析这些因素的存在性并提出了解决方式.%Reading is regarded as an important way of acquiring knowledge.It is a fact that many college non-English major students suffer from many reading barriers--linguistic and non-linguistic factors that affect their reading ability.In order to improve College English teaching and learning in reading,the reading barriers in non-English major students have been investigated with 200 sophorhores from Huizhou University.Questionnaires were delivered to the students to choose the factor that affects them greatly,slishtly or never.The result tells that it is not the linguistic factors that affect learners'reading comprehension mostly,for it has been paid much attention,but the non-linguistic factors are still affecting them greatly.This paper focuses on analyzing the non-linguistic factors'effects,which include background knowledge,culture difference,reading strategies/skills,reading habits,psychological factor,thinking models,and so on.Based on investigating and analyzing,correlative solution to the barriers is discussed.

  1. Selective Attention to Perceptual Dimensions and Switching between Dimensions

    Science.gov (United States)

    Meiran, Nachshon; Dimov, Eduard; Ganel, Tzvi

    2013-01-01

    In the present experiments, the question being addressed was whether switching attention between perceptual dimensions and selective attention to dimensions are processes that compete over a common resource? Attention to perceptual dimensions is usually studied by requiring participants to ignore a never-relevant dimension. Selection failure…

  2. Perceptual biases in relation to paranormal and conspiracy beliefs

    NARCIS (Netherlands)

    van Elk, M.

    2015-01-01

    Previous studies have shown that one’s prior beliefs have a strong effect on perceptual decision-making and attentional processing. The present study extends these findings by investigating how individual differences in paranormal and conspiracy beliefs are related to perceptual and attentional bias

  3. Perceptual Specificity Effects in Rereading: Evidence from Eye Movements

    Science.gov (United States)

    Sheridan, Heather; Reingold, Eyal M.

    2012-01-01

    The present experiments examined perceptual specificity effects using a rereading paradigm. Eye movements were monitored while participants read the same target word twice, in two different low-constraint sentence frames. The congruency of perceptual processing was manipulated by either presenting the target word in the same distortion typography…

  4. The Role of Perceptual Load in Inattentional Blindness

    Science.gov (United States)

    Cartwright-Finch, Ula; Lavie, Nilli

    2007-01-01

    Perceptual load theory offers a resolution to the long-standing early vs. late selection debate over whether task-irrelevant stimuli are perceived, suggesting that irrelevant perception depends upon the perceptual load of task-relevant processing. However, previous evidence for this theory has relied on RTs and neuroimaging. Here we tested the…

  5. Perceptual Specificity Effects in Rereading: Evidence from Eye Movements

    Science.gov (United States)

    Sheridan, Heather; Reingold, Eyal M.

    2012-01-01

    The present experiments examined perceptual specificity effects using a rereading paradigm. Eye movements were monitored while participants read the same target word twice, in two different low-constraint sentence frames. The congruency of perceptual processing was manipulated by either presenting the target word in the same distortion typography…

  6. Acetylcholine and Olfactory Perceptual Learning

    Science.gov (United States)

    Wilson, Donald A.; Fletcher, Max L.; Sullivan, Regina M.

    2004-01-01

    Olfactory perceptual learning is a relatively long-term, learned increase in perceptual acuity, and has been described in both humans and animals. Data from recent electrophysiological studies have indicated that olfactory perceptual learning may be correlated with changes in odorant receptive fields of neurons in the olfactory bulb and piriform…

  7. Perceptual learning in speech

    NARCIS (Netherlands)

    Norris, D.; McQueen, J.M.; Cutler, A.

    2003-01-01

    This study demonstrates that listeners use lexical knowledge in perceptual learning of speech sounds. Dutch listeners first made lexical decisions on Dutch words and nonwords. The final fricative of 20 critical words had been replaced by an ambiguous sound, between [f] and [s]. One group of listener

  8. Graphemes are perceptual reading units.

    Science.gov (United States)

    Rey, A; Ziegler, J C; Jacobs, A M

    2000-04-14

    Graphemes are commonly defined as the written representation of phonemes. For example, the word 'BREAD' is composed of the four phonemes /b/, /r/, /e/ and /d/, and consequently, of the four graphemes 'B', 'R', 'EA', and 'D'. Graphemes can thus be considered the minimal 'functional bridges' in the mapping between orthography and phonology. In the present study, we investigated the hypothesis that graphemes are processed as perceptual units by the reading system. If the reading system processes graphemes as units, then detecting a letter in a word should be harder when this letter is embedded in a multi-letter grapheme than when it corresponds to a single-letter grapheme. In Experiment 1A, done in English, participants were slower to detect a target letter in a word when the target letter was embedded in multi-letter grapheme (i.e. 'A' in 'BEACH') than when it corresponded to a single-letter grapheme (i.e. 'A' in 'PLACE'). In Experiment 1B, this effect was replicated in French. In Experiment 2, done in English, this grapheme effect remained when phonemic similarity between the target letter alone and the target letter inside the word was controlled. Together, the results are consistent with the assumption that graphemes are processed as perceptual reading units in alphabetic writing systems such as English or French.

  9. Perceptual memory drives learning of retinotopic biases for bistable stimuli.

    Directory of Open Access Journals (Sweden)

    Aidan Peter Murphy

    2014-02-01

    Full Text Available The visual system exploits past experience at multiple timescales to resolve perceptual ambiguity in the retinal image. For example, perception of a bistable stimulus can be biased towards one interpretation over another when preceded by a brief presentation of a disambiguated version of the stimulus (positive priming or through intermittent presentations of the ambiguous stimulus (stabilization. Similarly, prior presentations of unambiguous stimuli can be used to explicitly train a long-lasting association between a percept and a retinal location (perceptual association. These phenonema have typically been regarded as independent processes, with short-term biases attributed to perceptual memory and longer-term biases described as associative learning. Here we tested for interactions between these two forms of experience-dependent perceptual bias and demonstrate that short-term processes strongly influence long-term outcomes. We first demonstrate that the establishment of long-term perceptual contingencies does not require explicit training by unambiguous stimuli, but can arise spontaneously during the periodic presentation of brief, ambiguous stimuli. Using rotating Necker cube stimuli, we observed enduring, retinotopically specific perceptual biases that were expressed from the outset and remained stable for up to forty minutes, consistent with the known phenomenon of perceptual stabilization. Further, bias was undiminished after a break period of five minutes, but was readily reset by interposed periods of continuous, as opposed to periodic, ambiguous presentation. Taken together, the results demonstrate that perceptual biases can arise naturally and may principally reflect the brain’s tendency to favor recent perceptual interpretation at a given retinal location. Further, they suggest that an association between retinal location and perceptual state, rather than a physical stimulus, is sufficient to generate long-term biases in perceptual

  10. Perceptual learning and human expertise

    Science.gov (United States)

    Kellman, Philip J.; Garrigan, Patrick

    2009-06-01

    We consider perceptual learning: experience-induced changes in the way perceivers extract information. Often neglected in scientific accounts of learning and in instruction, perceptual learning is a fundamental contributor to human expertise and is crucial in domains where humans show remarkable levels of attainment, such as language, chess, music, and mathematics. In Section 2, we give a brief history and discuss the relation of perceptual learning to other forms of learning. We consider in Section 3 several specific phenomena, illustrating the scope and characteristics of perceptual learning, including both discovery and fluency effects. We describe abstract perceptual learning, in which structural relationships are discovered and recognized in novel instances that do not share constituent elements or basic features. In Section 4, we consider primary concepts that have been used to explain and model perceptual learning, including receptive field change, selection, and relational recoding. In Section 5, we consider the scope of perceptual learning, contrasting recent research, focused on simple sensory discriminations, with earlier work that emphasized extraction of invariance from varied instances in more complex tasks. Contrary to some recent views, we argue that perceptual learning should not be confined to changes in early sensory analyzers. Phenomena at various levels, we suggest, can be unified by models that emphasize discovery and selection of relevant information. In a final section, we consider the potential role of perceptual learning in educational settings. Most instruction emphasizes facts and procedures that can be verbalized, whereas expertise depends heavily on implicit pattern recognition and selective extraction skills acquired through perceptual learning. We consider reasons why perceptual learning has not been systematically addressed in traditional instruction, and we describe recent successful efforts to create a technology of perceptual

  11. Sensorineural hearing loss and auditory perceptual organization

    Science.gov (United States)

    Hall, Joseph W.; Grose, John H.; Buss, Emily

    2004-05-01

    This talk will consider the implications of sensorineural hearing loss for auditory perceptual organization. In everyday environments, the listener is often faced with the difficulty of processing a target sound that intermingles acoustically with one or more extraneous sounds. Under such circumstances, several auditory processes enable the complex waveforms reaching the two ears to be interpreted in terms of putative auditory objects giving rise to the target and extraneous sounds. Such processes of perceptual organization depend upon the central analysis of cues that allow distributed spectral information to be either linked together or split apart on the basis of details related to such variables as synchrony of onset/modulation, harmonic relation, rhythm, and interaural differences. Efficient perceptual organization must depend not only upon such central auditory analyses but also upon the fidelity with which the peripheral auditory system encodes the spectral and temporal characteristics of sound. We will consider the implications of sensorineural hearing loss for perceptual organization in terms of both peripheral and central auditory processes.

  12. Perceptual digital imaging methods and applications

    CERN Document Server

    Lukac, Rastislav

    2012-01-01

    Visual perception is a complex process requiring interaction between the receptors in the eye that sense the stimulus and the neural system and the brain that are responsible for communicating and interpreting the sensed visual information. This process involves several physical, neural, and cognitive phenomena whose understanding is essential to design effective and computationally efficient imaging solutions. Building on advances in computer vision, image and video processing, neuroscience, and information engineering, perceptual digital imaging greatly enhances the capabilities of tradition

  13. Development of the perceptual span in reading: A longitudinal study.

    Science.gov (United States)

    Sperlich, Anja; Meixner, Johannes; Laubrock, Jochen

    2016-06-01

    The perceptual span is a standard measure of parafoveal processing, which is considered highly important for efficient reading. Is the perceptual span a stable indicator of reading performance? What drives its development? Do initially slower and faster readers converge or diverge over development? Here we present the first longitudinal data on the development of the perceptual span in elementary school children. Using the moving window technique, eye movements of 127 German children in three age groups (Grades 1, 2, and 3 in Year 1) were recorded at two time points (T1 and T2) 1 year apart. Introducing a new measure of the perceptual span, nonlinear mixed-effects modeling was used to separate window size effects from asymptotic reading performance. Cross-sectional differences were well replicated longitudinally. Asymptotic reading rate increased monotonously with grade, but in a decelerating fashion. A significant change in the perceptual span was observed only between Grades 2 and 3. Together with results from a cross-lagged panel model, this suggests that the perceptual span increases as a consequence of relatively well-established word reading. Stabilities of observed and predicted reading rates were high after Grade 1, whereas the perceptual span was only moderately stable for all grades. Comparing faster and slower readers as assessed at T1, in general, a pattern of stable between-group differences emerged rather than a compensatory pattern; second and third graders even showed a Matthew effect in reading rate and the perceptual span, respectively.

  14. The neural basis of implicit perceptual sequence learning

    Directory of Open Access Journals (Sweden)

    Freja eGheysen

    2011-11-01

    Full Text Available The present fMRI study investigated the neural areas involved in implicit perceptual sequence learning. To obtain more insight in the functional contributions of the brain areas, we tracked both the behavioral and neural time course of the learning process, using a perceptual serial color matching task. Next, to investigate whether the neural time course was specific for perceptual information, imaging results were compared to the results of implicit motor sequence learning, previously investigated using an identical serial color matching task. Results indicated that implicit sequences can be acquired by at least two neural systems: the caudate nucleus and the hippocampus, having different operating principles. The caudate nucleus contributed to the implicit sequence learning process for perceptual as well as motor information in a similar and gradual way. The hippocampus, on the other hand, was engaged in a much faster learning process which was more pronounced for the motor compared to the perceptual task. Interestingly, the perceptual and motor learning process occurred on a comparable implicit level, suggesting that consciousness is not the main determinant factor dissociating the hippocampal from the caudate learning system. This study is not only the first to successfully and unambiguously compare brain activation between perceptual and motor levels of implicit sequence learning, it also provides new insights into the specific hippocampal and caudate learning function.

  15. Rapid image-segmentation and perceptual transparency share a process which utilises X-junctions generated by temporal integration in the visual system.

    Science.gov (United States)

    Mitsudo, Hiroyuki

    2004-01-01

    Perceptual transparency requires local same-polarity X-junctions, which can also be generated by temporal integration under natural dynamic conditions. In this study, segmentation performance and target appearance were measured for a uniform gray target embedded in a random-dot frame presented with a temporally adjacent mask. Although static cues for both segmentation and transparency were unavailable, transparency was observed only when collinear same-polarity edges reduced backward masking, in both the fovea and the perifovea. These results suggest that the visual system has a common underlying mechanism for rapid segmentation and transparency, which utilises same-polarity X-junctions generated by temporal integration.

  16. Prior expectations facilitate metacognition for perceptual decision.

    Science.gov (United States)

    Sherman, M T; Seth, A K; Barrett, A B; Kanai, R

    2015-09-01

    The influential framework of 'predictive processing' suggests that prior probabilistic expectations influence, or even constitute, perceptual contents. This notion is evidenced by the facilitation of low-level perceptual processing by expectations. However, whether expectations can facilitate high-level components of perception remains unclear. We addressed this question by considering the influence of expectations on perceptual metacognition. To isolate the effects of expectation from those of attention we used a novel factorial design: expectation was manipulated by changing the probability that a Gabor target would be presented; attention was manipulated by instructing participants to perform or ignore a concurrent visual search task. We found that, independently of attention, metacognition improved when yes/no responses were congruent with expectations of target presence/absence. Results were modeled under a novel Bayesian signal detection theoretic framework which integrates bottom-up signal propagation with top-down influences, to provide a unified description of the mechanisms underlying perceptual decision and metacognition. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. The emergence of semantic categorization in early visual processing: ERP indices of animal vs. artifact recognition

    Directory of Open Access Journals (Sweden)

    Del Zotto Marzia

    2007-04-01

    Full Text Available Abstract Background Neuroimaging and neuropsychological literature show functional dissociations in brain activity during processing of stimuli belonging to different semantic categories (e.g., animals, tools, faces, places, but little information is available about the time course of object perceptual categorization. The aim of the study was to provide information about the timing of processing stimuli from different semantic domains, without using verbal or naming paradigms, in order to observe the emergence of non-linguistic conceptual knowledge in the ventral stream visual pathway. Event related potentials (ERPs were recorded in 18 healthy right-handed individuals as they performed a perceptual categorization task on 672 pairs of images of animals and man-made objects (i.e., artifacts. Results Behavioral responses to animal stimuli were ~50 ms faster and more accurate than those to artifacts. At early processing stages (120–180 ms the right occipital-temporal cortex was more activated in response to animals than to artifacts as indexed by posterior N1 response, while frontal/central N1 (130–160 showed the opposite pattern. In the next processing stage (200–260 the response was stronger to artifacts and usable items at anterior temporal sites. The P300 component was smaller, and the central/parietal N400 component was larger to artifacts than to animals. Conclusion The effect of animal and artifact categorization emerged at ~150 ms over the right occipital-temporal area as a stronger response of the ventral stream to animate, homomorphic, entities with faces and legs. The larger frontal/central N1 and the subsequent temporal activation for inanimate objects might reflect the prevalence of a functional rather than perceptual representation of manipulable tools compared to animals. Late ERP effects might reflect semantic integration and cognitive updating processes. Overall, the data are compatible with a modality-specific semantic memory

  18. Perceptual Audio Hashing Functions

    Directory of Open Access Journals (Sweden)

    Emin Anarım

    2005-07-01

    Full Text Available Perceptual hash functions provide a tool for fast and reliable identification of content. We present new audio hash functions based on summarization of the time-frequency spectral characteristics of an audio document. The proposed hash functions are based on the periodicity series of the fundamental frequency and on singular-value description of the cepstral frequencies. They are found, on one hand, to perform very satisfactorily in identification and verification tests, and on the other hand, to be very resilient to a large variety of attacks. Moreover, we address the issue of security of hashes and propose a keying technique, and thereby a key-dependent hash function.

  19. Fusion of perceptions for perceptual robotics

    OpenAIRE

    Ciftcioglu, O.; Bittermann, M.S.; Sariyildiz, I.S.

    2006-01-01

    Fusion of perception information for perceptual robotics is described. The visual perception is mathematically modelled as a probabilistic process obtaining and interpreting visual data from an environment. The visual data is processed in a multiresolutional form via wavelet transform and optimally estimated via extended Kalman filtering in each resolution level and the outcomes are fused for each data block. The measurement involves visual perception in the virtual reality which has direct i...

  20. Perceptual crossing: the simplest online paradigm

    Science.gov (United States)

    Auvray, Malika; Rohde, Marieke

    2012-01-01

    Researchers in social cognition increasingly realize that many phenomena cannot be understood by investigating offline situations only, focusing on individual mechanisms and an observer perspective. There are processes of dynamic emergence specific to online situations, when two or more persons are engaged in a real-time interaction that are more than just the sum of the individual capacities or behaviors, and these require the study of online social interaction. Auvray et al.'s (2009) perceptual crossing paradigm offers possibly the simplest paradigm for studying such online interactions: two persons, a one-dimensional space, one bit of information, and a yes/no answer. This study has provoked a lot of resonance in different areas of research, including experimental psychology, computer/robot modeling, philosophy, psychopathology, and even in the field of design. In this article, we review and critically assess this body of literature. We give an overview of both behavioral experimental research and simulated agent modeling done using the perceptual crossing paradigm. We discuss different contexts in which work on perceptual crossing has been cited. This includes the controversy about the possible constitutive role of perceptual crossing for social cognition. We conclude with an outlook on future research possibilities, in particular those that could elucidate the link between online interaction dynamics and individual social cognition. PMID:22723776

  1. Perceptualization of scientific data

    Science.gov (United States)

    Grinstein, Georges G.; Smith, Stuart

    1990-08-01

    In this paper we discuss data exploration as a particularly difficult case within the general problem of data visualization. We describe (1) a novel graphic technique for displaying multidimensional data visually and (2) an auditory display integrated with the visual display that allows us to represent multidimensional data in sound. The visual/auditory display employs an "iconographic" technique that seeks to exploit the spontaneous perceptual capacity to sense and discriminate texture. Structures in data to be analyzed can appear, both visually and aurally, as distinct textural regions and contours when the data are represented iconographically. Sound can be used to reinforce the visual presentation or to augment the dimensionality of the visual display. The immediate focus of the work reported here is to investigate how best to transform data into perceptible visual and auditory textures, that is, how best to "perceptualize" the data. A key problem we discuss is deciding which fields of a multidimensional data set should be represented in the visual domain and which in the auditory domain. This activity is part of the University of Lowell's Exploratory Visualization (Exvis) project, a multidisciplinary effort to develop new paradigms for the exploration and analysis of data with high dimensionality.

  2. Perceptual Constraints in Phonotactic Learning

    Science.gov (United States)

    Endress, Ansgar D.; Mehler, Jacques

    2010-01-01

    Structural regularities in language have often been attributed to symbolic or statistical general purpose computations, whereas perceptual factors influencing such generalizations have received less interest. Here, we use phonotactic-like constraints as a case study to ask whether the structural properties of specific perceptual and memory…

  3. Integrated approaches to perceptual learning.

    Science.gov (United States)

    Jacobs, Robert A

    2010-04-01

    New technologies and new ways of thinking have recently led to rapid expansions in the study of perceptual learning. We describe three themes shared by many of the nine articles included in this topic on Integrated Approaches to Perceptual Learning. First, perceptual learning cannot be studied on its own because it is closely linked to other aspects of cognition, such as attention, working memory, decision making, and conceptual knowledge. Second, perceptual learning is sensitive to both the stimulus properties of the environment in which an observer exists and to the properties of the tasks that the observer needs to perform. Moreover, the environmental and task properties can be characterized through their statistical regularities. Finally, the study of perceptual learning has important implications for society, including implications for science education and medical rehabilitation. Contributed articles relevant to each theme are summarized.

  4. Exploring Perceptual Skills in Children with Autism Spectrum Disorders: From Target Detection to Dynamic Perceptual Discrimination

    Science.gov (United States)

    Miller, Louisa; McGonigle-Chalmers, Maggie

    2014-01-01

    Perceptual processing in autism is associated with both "strengths" and "weaknesses" but within a literature that varies widely in terms of the assessments used. We report data from 12 children with autism spectrum disorders (ASD) and 12 age and IQ matched neurotypical controls tested on a set of tasks using the same stimuli…

  5. Cultural differences in perceptual reorganization in US and Piraha adults.

    Directory of Open Access Journals (Sweden)

    Jennifer M D Yoon

    Full Text Available Visual illusions and other perceptual phenomena can be used as tools to uncover the otherwise hidden constructive processes that give rise to perception. Although many perceptual processes are assumed to be universal, variable susceptibility to certain illusions and perceptual effects across populations suggests a role for factors that vary culturally. One striking phenomenon is seen with two-tone images-photos reduced to two tones: black and white. Deficient recognition is observed in young children under conditions that trigger automatic recognition in adults. Here we show a similar lack of cue-triggered perceptual reorganization in the Pirahã, a hunter-gatherer tribe with limited exposure to modern visual media, suggesting such recognition is experience- and culture-specific.

  6. Perceptual discrimination in fear generalization: Mechanistic and clinical implications.

    Science.gov (United States)

    Struyf, Dieter; Zaman, Jonas; Vervliet, Bram; Van Diest, Ilse

    2015-12-01

    For almost a century, Pavlovian conditioning is the imperative experimental paradigm to investigate the development and generalization of fear. However, despite the rich research tradition, the conceptualization of fear generalization has remained somewhat ambiguous. In this selective review, we focus explicitly on some challenges with the current operationalization of fear generalization and their impact on the ability to make inferences on its clinical potential and underlying processes. The main conclusion is that, despite the strong evidence that learning influences perception, current research has largely neglected the role of perceptual discriminability and its plasticity in fear generalization. We propose an alternative operationalization of generalization, where the essence is that Pavlovian conditioning itself influences the breadth of fear generalization via learning-related changes in perceptual discriminability. Hence a conceptualization of fear generalization is incomplete without an in-depth analysis of processes of perceptual discriminability. Furthermore, this highlights perceptual learning and discriminability as important future targets for pre-clinical and clinical research.

  7. Generalized perceptual features for animal vocalization classification

    Science.gov (United States)

    Clemins, Patrick J.; Johnson, Michael T.

    2001-05-01

    Two sets of generalized, perceptual-based features are investigated for use in classifying animal vocalizations. Since many species, especially mammals, share similar physical sound perception mechanisms which vary in size, two features sets commonly used in human speech processing, mel-frequency cepstral coefficients (MFCCs) and perceptual linear prediction (PLP) analysis, are modified for use in other species. One modification made to the feature extraction process is incorporating the frequency range of hearing and length of the basilar membrane of the animal in order to correctly determine the width and location of the critical band filters used for signal processing. Experimentally determined critical bands (equivalent rectangular bandwidth) and equal loudness curves (audiograms) can also be incorporated directly into the feature extraction process. Experiments are performed on African elephant (Loxodonta africana) vocalizations using a hidden Markov model (HMM) based classifier showing increased classification accuracy when using features sets based on the specific animals perceptual abilities compared to the original human perception-based feature sets.

  8. Neurophysiological mechanisms involved in auditory perceptual organization

    Directory of Open Access Journals (Sweden)

    Aurélie Bidet-Caulet

    2009-09-01

    Full Text Available In our complex acoustic environment, we are confronted with a mixture of sounds produced by several simultaneous sources. However, we rarely perceive these sounds as incomprehensible noise. Our brain uses perceptual organization processes to independently follow the emission of each sound source over time. If the acoustic properties exploited in these processes are well-established, the neurophysiological mechanisms involved in auditory scene analysis have raised interest only recently. Here, we review the studies investigating these mechanisms using electrophysiological recordings from the cochlear nucleus to the auditory cortex, in animals and humans. Their findings reveal that basic mechanisms such as frequency selectivity, forward suppression and multi-second habituation shape the automatic brain responses to sounds in a way that can account for several important characteristics of perceptual organization of both simultaneous and successive sounds. One challenging question remains unresolved: how are the resulting activity patterns integrated to yield the corresponding conscious perceptsµ

  9. Effects of musicianship and experimental task on perceptual segmentation

    DEFF Research Database (Denmark)

    Hartmann, Martin; Lartillot, Olivier; Toiviainen, Petri

    2015-01-01

    The perceptual structure of music is a fundamental issue in music psychology that can be systematically addressed via computational models. This study estimated the contribution of spectral, rhythmic and tonal descriptors for prediction of perceptual segmentation across stimuli. In a real-time task...... dependency. The role of interactions on perception of musical change has an impact on the study of neural, kinetic and speech stream processing....

  10. The Cultural Differences of Non-linguistic Communication between China and English-Speaking Countries%中英非语言交际的文化差异探究

    Institute of Scientific and Technical Information of China (English)

    崔振芳; 肖巧萍

    2015-01-01

    Non-linguistic communication plays an important role in human communication, which can ex⁃press the inner feeling, difficult to show for the linguistic communication. The paper compares the differences of non-linguistic communication between China and English-speaking countries from the body language, non-verbal language and so on, and expounds the reasons why there exits the differences.%当今社会,来自中英两个不同文化国家的交往越来越频繁,了解中英非语言交际的差异性显得异常重要。本文从中英文化差异的角度对体态语、副语言等几个方面进行了对比,剖析了形成中英非语言交际文化差异的原因。

  11. Perceptual training for visual search.

    Science.gov (United States)

    Schuster, David; Rivera, Javier; Sellers, Brittany C; Fiore, Stephen M; Jentsch, Florian

    2013-01-01

    People are better at visual search than the best fully automated methods. Despite this, visual search remains a difficult perceptual task. The goal of this investigation was to experimentally test the ways in which visual search performance could be improved through two categories of training interventions: perceptual training and conceptual training. To determine the effects of each training on a later performance task, the two types of trainings were manipulated using a between-subjects design (conceptual vs. perceptual × training present vs. training absent). Perceptual training led to speed and accuracy improvements in visual search. Issues with the design and administration of the conceptual training limited conclusions on its effectiveness but provided useful lessons for conceptual training design. The results suggest that when the visual search task involves detecting heterogeneous or otherwise unpredictable stimuli, perceptual training can improve visual search performance. Similarly, careful consideration of the performance task and training design is required to evaluate the effectiveness of conceptual training. Visual search is a difficult, yet critical, task in industries such as baggage screening and radiology. This study investigated the effectiveness of perceptual training for visual search. The results suggest that when visual search involves detecting heterogeneous or otherwise unpredictable stimuli, perceptual training may improve the speed and accuracy of visual search.

  12. Perceptual learning in sensorimotor adaptation.

    Science.gov (United States)

    Darainy, Mohammad; Vahdat, Shahabeddin; Ostry, David J

    2013-11-01

    Motor learning often involves situations in which the somatosensory targets of movement are, at least initially, poorly defined, as for example, in learning to speak or learning the feel of a proper tennis serve. Under these conditions, motor skill acquisition presumably requires perceptual as well as motor learning. That is, it engages both the progressive shaping of sensory targets and associated changes in motor performance. In the present study, we test the idea that perceptual learning alters somatosensory function and in so doing produces changes to human motor performance and sensorimotor adaptation. Subjects in these experiments undergo perceptual training in which a robotic device passively moves the subject's arm on one of a set of fan-shaped trajectories. Subjects are required to indicate whether the robot moved the limb to the right or the left and feedback is provided. Over the course of training both the perceptual boundary and acuity are altered. The perceptual learning is observed to improve both the rate and extent of learning in a subsequent sensorimotor adaptation task and the benefits persist for at least 24 h. The improvement in the present studies varies systematically with changes in perceptual acuity and is obtained regardless of whether the perceptual boundary shift serves to systematically increase or decrease error on subsequent movements. The beneficial effects of perceptual training are found to be substantially dependent on reinforced decision-making in the sensory domain. Passive-movement training on its own is less able to alter subsequent learning in the motor system. Overall, this study suggests perceptual learning plays an integral role in motor learning.

  13. Perceptual inference and autistic traits

    DEFF Research Database (Denmark)

    Skewes, Joshua; Jegindø, Else-Marie Elmholdt; Gebauer, Line

    2015-01-01

    Autistic people are better at perceiving details. Major theories explain this in terms of bottom-up sensory mechanisms, or in terms of top-down cognitive biases. Recently, it has become possible to link these theories within a common framework. This framework assumes that perception is implicit...... neural inference, combining sensory evidence with prior perceptual knowledge. Within this framework, perceptual differences may occur because of enhanced precision in how sensory evidence is represented, or because sensory evidence is weighted much higher than prior perceptual knowledge...

  14. Looking without Perceiving: Impaired Preattentive Perceptual Grouping in Autism Spectrum Disorder

    OpenAIRE

    Tiffany A Carther-Krone; Sarah Shomstein; Marotta, Jonathan J.

    2016-01-01

    Before becoming aware of a visual scene, our perceptual system has organized and selected elements in our environment to which attention should be allocated. Part of this process involves grouping perceptual features into a global whole. Individuals with autism spectrum disorders (ASD) rely on a more local processing strategy, which may be driven by difficulties perceptually grouping stimuli. We tested this notion using a line discrimination task in which two horizontal lines were superimpose...

  15. Temporal characteristics of the influence of punishment on perceptual decision making in the human brain

    OpenAIRE

    Blank, H.; Guido, B.; Heekeren, H.R.; Philiastides, M.G.

    2013-01-01

    Perceptual decision making is the process by which information from sensory systems is combined and used to influence our behavior. In addition to the sensory input, this process can be affected by other factors, such as reward and punishment for correct and incorrect responses. To investigate the temporal dynamics of how monetary punishment influences perceptual decision making in humans, we collected electroencephalography (EEG) data during a perceptual categorization task whereby the punis...

  16. Perceptual Load Modulates Object-Based Attention

    Science.gov (United States)

    Ho, Ming-Chou; Atchley, Paul

    2009-01-01

    Two experimental series are reported using both reaction time (RT) and a data-limited perceptual report to examine the effects of perceptual load on object-based attention. Perceptual load was manipulated across 3 levels by increasing the complexity of perceptual judgments. Data from the RT-based experiments showed object-based effects when the…

  17. Surprise Leads to Noisier Perceptual Decisions

    Directory of Open Access Journals (Sweden)

    Marta I Garrido

    2011-02-01

    Full Text Available Surprising events in the environment can impair task performance. This might be due to complete distraction, leading to lapses during which performance is reduced to guessing. Alternatively, unpredictability might cause a graded withdrawal of perceptual resources from the task at hand and thereby reduce sensitivity. Here we attempt to distinguish between these two mechanisms. Listeners performed a novel auditory pitch—duration discrimination, where stimulus loudness changed occasionally and incidentally to the task. Responses were slower and less accurate in the surprising condition, where loudness changed unpredictably, than in the predictable condition, where the loudness was held constant. By explicitly modelling both lapses and changes in sensitivity, we found that unpredictable changes diminished sensitivity but did not increase the rate of lapses. These findings suggest that background environmental uncertainty can disrupt goal-directed behaviour. This graded processing strategy might be adaptive in potentially threatening contexts, and reflect a flexible system for automatic allocation of perceptual resources.

  18. Perceptual consequences of "hidden" hearing loss.

    Science.gov (United States)

    Plack, Christopher J; Barker, Daphne; Prendergast, Garreth

    2014-09-09

    Dramatic results from recent animal experiments show that noise exposure can cause a selective loss of high-threshold auditory nerve fibers without affecting absolute sensitivity permanently. This cochlear neuropathy has been described as hidden hearing loss, as it is not thought to be detectable using standard measures of audiometric threshold. It is possible that hidden hearing loss is a common condition in humans and may underlie some of the perceptual deficits experienced by people with clinically normal hearing. There is some evidence that a history of noise exposure is associated with difficulties in speech discrimination and temporal processing, even in the absence of any audiometric loss. There is also evidence that the tinnitus experienced by listeners with clinically normal hearing is associated with cochlear neuropathy, as measured using Wave I of the auditory brainstem response. To date, however, there has been no direct link made between noise exposure, cochlear neuropathy, and perceptual difficulties. Animal experiments also reveal that the aging process itself, in the absence of significant noise exposure, is associated with loss of auditory nerve fibers. Evidence from human temporal bone studies and auditory brainstem response measures suggests that this form of hidden loss is common in humans and may have perceptual consequences, in particular, regarding the coding of the temporal aspects of sounds. Hidden hearing loss is potentially a major health issue, and investigations are ongoing to identify the causes and consequences of this troubling condition.

  19. Perceptual Load Affects Eyewitness Accuracy and Susceptibility to Leading Questions

    Science.gov (United States)

    Murphy, Gillian; Greene, Ciara M.

    2016-01-01

    Load Theory (Lavie, 1995, 2005) states that the level of perceptual load in a task (i.e., the amount of information involved in processing task-relevant stimuli) determines the efficiency of selective attention. There is evidence that perceptual load affects distractor processing, with increased inattentional blindness under high load. Given that high load can result in individuals failing to report seeing obvious objects, it is conceivable that load may also impair memory for the scene. The current study is the first to assess the effect of perceptual load on eyewitness memory. Across three experiments (two video-based and one in a driving simulator), the effect of perceptual load on eyewitness memory was assessed. The results showed that eyewitnesses were less accurate under high load, in particular for peripheral details. For example, memory for the central character in the video was not affected by load but memory for a witness who passed by the window at the edge of the scene was significantly worse under high load. High load memories were also more open to suggestion, showing increased susceptibility to leading questions. High visual perceptual load also affected recall for auditory information, illustrating a possible cross-modal perceptual load effect on memory accuracy. These results have implications for eyewitness memory researchers and forensic professionals. PMID:27625628

  20. Perceptual Load Affects Eyewitness Accuracy & Susceptibility to Leading Questions

    Directory of Open Access Journals (Sweden)

    Gillian Murphy

    2016-08-01

    Full Text Available Load Theory (Lavie, 1995; 2005 states that the level of perceptual load in a task (i.e. the amount of information involved in processing task-relevant stimuli determines the efficiency of selective attention. There is evidence that perceptual load affects distractor processing, with increased inattentional blindness under high load. Given that high load can result in individuals failing to report seeing obvious objects, it is conceivable that load may also impair memory for the scene. The current study is the first to assess the effect of perceptual load on eyewitness memory. Across three experiments (two video-based and one in a driving simulator, the effect of perceptual load on eyewitness memory was assessed. The results showed that eyewitnesses were less accurate under high load, in particular for peripheral details. For example, memory for the central character in the video was not affected by load but memory for a witness who passed by the window at the edge of the scene was significantly worse under high load. High load memories were also more open to suggestion, showing increased susceptibility to leading questions. High visual perceptual load also affected recall for auditory information, illustrating a possible cross-modal perceptual load effect on memory accuracy. These results have implications for eyewitness memory researchers and forensic professionals.

  1. Automatic imitation? Imitative compatibility affects responses at high perceptual load.

    Science.gov (United States)

    Catmur, Caroline

    2016-04-01

    Imitation involves matching the visual representation of another's action onto the observer's own motor program for that action. However, there has been some debate regarding the extent to which imitation is "automatic"-that is, occurs without attention. Participants performed a perceptual load task in which images of finger movements were presented as distractors. Responses to target letter stimuli were performed via finger movements that could be imitatively compatible (requiring the same finger movement) or incompatible with the distractor movements: In this common stimulus-response compatibility manipulation, the stimulus set comprises images of the response movements, producing an imitative compatibility effect. Attention to the distractor movements was manipulated by altering perceptual load through increasing the number of nontarget letter stimuli. If imitation requires attention, then at high perceptual load, imitative compatibility should not affect response times. In contrast, imitative compatibility influenced response times at high perceptual load, demonstrating that distractor movements were processed. However, the compatibility effect was reversed, suggesting that longer response times at high perceptual load tap into an inhibitory stage of distractor movement processing. A follow-up experiment manipulating temporal delay between targets and distractor movements supported this explanation. Further experiments confirmed that nonmovement distractor stimuli in the same configuration produced standard perceptual load effects and that results were not solely due to effector compatibility. These data suggest that imitation can occur without attention. (PsycINFO Database Record

  2. Perceptual Load Affects Eyewitness Accuracy and Susceptibility to Leading Questions.

    Science.gov (United States)

    Murphy, Gillian; Greene, Ciara M

    2016-01-01

    Load Theory (Lavie, 1995, 2005) states that the level of perceptual load in a task (i.e., the amount of information involved in processing task-relevant stimuli) determines the efficiency of selective attention. There is evidence that perceptual load affects distractor processing, with increased inattentional blindness under high load. Given that high load can result in individuals failing to report seeing obvious objects, it is conceivable that load may also impair memory for the scene. The current study is the first to assess the effect of perceptual load on eyewitness memory. Across three experiments (two video-based and one in a driving simulator), the effect of perceptual load on eyewitness memory was assessed. The results showed that eyewitnesses were less accurate under high load, in particular for peripheral details. For example, memory for the central character in the video was not affected by load but memory for a witness who passed by the window at the edge of the scene was significantly worse under high load. High load memories were also more open to suggestion, showing increased susceptibility to leading questions. High visual perceptual load also affected recall for auditory information, illustrating a possible cross-modal perceptual load effect on memory accuracy. These results have implications for eyewitness memory researchers and forensic professionals.

  3. Perceptually Lossless Wavelet Compression

    Science.gov (United States)

    Watson, Andrew B.; Yang, Gloria Y.; Solomon, Joshua A.; Villasenor, John

    1996-01-01

    The Discrete Wavelet Transform (DWT) decomposes an image into bands that vary in spatial frequency and orientation. It is widely used for image compression. Measures of the visibility of DWT quantization errors are required to achieve optimal compression. Uniform quantization of a single band of coefficients results in an artifact that is the sum of a lattice of random amplitude basis functions of the corresponding DWT synthesis filter, which we call DWT uniform quantization noise. We measured visual detection thresholds for samples of DWT uniform quantization noise in Y, Cb, and Cr color channels. The spatial frequency of a wavelet is r 2(exp -1), where r is display visual resolution in pixels/degree, and L is the wavelet level. Amplitude thresholds increase rapidly with spatial frequency. Thresholds also increase from Y to Cr to Cb, and with orientation from low-pass to horizontal/vertical to diagonal. We propose a mathematical model for DWT noise detection thresholds that is a function of level, orientation, and display visual resolution. This allows calculation of a 'perceptually lossless' quantization matrix for which all errors are in theory below the visual threshold. The model may also be used as the basis for adaptive quantization schemes.

  4. Perceptually specific and perceptually non-specific influences on rereading benefits for spatially transformed text: evidence from eye movements.

    Science.gov (United States)

    Sheridan, Heather; Reingold, Eyal M

    2012-12-01

    The present study used eye tracking methodology to examine rereading benefits for spatially transformed text. Eye movements were monitored while participants read the same target word twice, in two different low-constraint sentence frames. The congruency of perceptual processing was manipulated by either applying the same type of transformation to the word during the first and second presentations (i.e., the congruent condition), or employing two different types of transformations across the two presentations of the word (i.e., the incongruent condition). Perceptual specificity effects were demonstrated such that fixation times for the second presentation of the target word were shorter for the congruent condition compared to the incongruent condition. Moreover, we demonstrated an additional perceptually non-specific effect such that second reading fixation times were shorter for the incongruent condition relative to a baseline condition that employed a normal typography (i.e., non-transformed) during the first presentation and a transformation during the second presentation. Both of these effects (i.e., perceptually specific and perceptually non-specific) were similar in magnitude for high and low frequency words, and both effects persisted across a 1 week lag between the first and second readings. We discuss the present findings in the context of the distinction between conscious and unconscious memory, and the distinction between perceptually versus conceptually driven processing. Copyright © 2012 Elsevier Inc. All rights reserved.

  5. Prolonged perceptual learning of positional acuity in adult amblyopia: perceptual template retuning dynamics.

    Science.gov (United States)

    Li, Roger W; Klein, Stanley A; Levi, Dennis M

    2008-12-24

    Amblyopia is a developmental abnormality that results in physiological alterations in the visual cortex and impairs form vision. It is often successfully treated by patching the sound eye in infants and young children, but is generally considered to be untreatable in adults. However, a number of recent studies suggest that repetitive practice of a visual task using the amblyopic eye results in improved performance in both children and adults with amblyopia. These perceptual learning studies have used relatively brief periods of practice; however, clinical studies have shown that the time-constant for successful patching is long. The time-constant for perceptual learning in amblyopia is still unknown. Here we show that the time-constant for perceptual learning depends on the degree of amblyopia. Severe amblyopia requires >50 h (approximately equal to 35,000 trials) to reach plateau, yielding as much as a five-fold improvement in performance at a rate of approximately equal to 1.5%/h. There is significant transfer of learning from the amblyopic to the dominant eye, suggesting that the learning reflects alterations in higher decision stages of processing. Using a reverse correlation technique, we document, for the first time, a dynamic retuning of the amblyopic perceptual decision template and a substantial reduction in internal spatial distortion. These results show that the mature amblyopic brain is surprisingly malleable, and point to more intensive treatment methods for amblyopia.

  6. Perceptual advantage for category-relevant perceptual dimensions: The case of shape and motion

    Directory of Open Access Journals (Sweden)

    Jonathan R Folstein

    2014-12-01

    Full Text Available Category learning facilitates perception along relevant stimulus dimensions, even when tested in a discrimination task that does not require categorization. While this general phenomenon has been demonstrated previously, perceptual facilitation along dimensions has been documented by measuring different specific phenomena in different studies using different kinds of objects. Across several object domains, there is support for acquired distinctiveness, the stretching of a perceptual dimension relevant to learned categories. Studies using faces and studies using simple separable visual dimensions have also found evidence of acquired equivalence, the shrinking of a perceptual dimension irrelevant to learned categories, and categorical perception, the local stretching across the category boundary. These later two effects are rarely observed with complex non-face objects. Failures to find these effects with complex non-face objects may have been because the dimensions tested previously were perceptually integrated. Here we tested effects of category learning with non-face objects categorized along dimensions that have been found to be processed by different areas of the brain, shape and motion. While we replicated acquired distinctiveness, we found no evidence for acquired equivalence or categorical perception.

  7. Interocular transfer of perceptual skills after sleep.

    Science.gov (United States)

    Deliens, Gaétane; Schmitz, Rémy; Peigneux, Philippe

    2014-01-24

    Several studies suggest that sleep improves perceptual skills in the visual texture discrimination task (TDT). Here we report that besides consolidation, sleep also generalizes the learned perceptual abilities to the untrained eye. Healthy volunteers (n = 32) were trained on the TDT, in which they had to discriminate between horizontal and vertical target textures briefly presented in the periphery of the visual field (left upper quadrant). After a 10-hr interval filled with either sleep or wakefulness, they were retested first on the trained eye in the trained quadrant and then on the untrained eye and quadrant. In line with prior findings, visual discrimination was globally higher after sleep than after wakefulness, as compared to performance levels at the end of training. Furthermore, discrimination performance was significantly improved only in the sleep condition for the untrained eye in the same quadrant, but also showed a trend to generalize to the untrained eye and untrained quadrant. Our results suggest that sleep-dependent perceptual skills continue developing at a later visual-process stage than the V1 area, where learning is not monocular anymore.

  8. Perceptual crossing: The simplest online paradigm

    Directory of Open Access Journals (Sweden)

    Malika eAuvray

    2012-06-01

    Full Text Available Researchers in social cognition increasingly realize that many phenomena cannot be understood by investigating offline situations only, focusing on individual mechanisms and an observer perspective. There are processes of dynamic emergence specific to online situations, when two or more persons are engaged in a real-time interaction that are more than just the sum of the individual capacities or behaviours, and these require the study of online social interaction. Auvray et al.’s (2009 perceptual crossing paradigm offers possibly the simplest paradigm for studying such online interactions: two persons, a one-dimensional space, one bit of information, and a yes/no answer. Despite, or maybe because of its simplicity, this study has provoked a lot of resonance in different areas of research, including experimental psychology, computer/robot modelling, philosophy, more recently psychopathology, and even in the field of design. In this article, we review and critically assess this body of literature. We give an overview over work on the perceptual crossing paradigm, both concerning behavioural experiments and computational agent modelling, and review the different contexts in which it has been referred to. We discuss the controversy about the possible constitutive role of perceptual crossing for social cognition and other theoretical contexts in which the research has been cited, offering our own interpretation. We conclude with an outlook on future research possibilities, in particular those that could elucidate the link between online interaction dynamics and individual social cognition.

  9. 标识牌译文误因之语外因素概述%Non-linguistic Causes for the Translation Errors on the Sign Boards

    Institute of Scientific and Technical Information of China (English)

    王作伟

    2014-01-01

    Thestudies on public sign translation focus more on language analysis ,such as the use of language ,style and the function of the translated text .Studies concentrated on the linguistic elements mainly find out the language problems and provide correct translation ,or analyze the translated text from the perspectives of translation theory or linguistics theory and correct the errors .These language-oriented studies ascribe the error causes to the translators and translation strategies adopted .But seen from the purpose of translation ,the purpose is made by many factors and the translator is only one of them .The analysis of the non-linguistic causes helps to produce correct translated text on sign boards by taking advantage of all the factors .%标识语翻译的研究大多集中在对语言的分析上,比如语言是否正确,语体是否恰当,翻译效果是否符合标识语的语言功能等。这些集中在语言内部因素的分析大多都是找出语言问题,予以纠正;或者从翻译理论或语言学理论来分析译文,然后纠正错误。这类从语言本身着手的研究都把标识牌译文的错误归因于译者的语言能力、文化积淀和翻译策略。但从翻译目的角度来看,促成翻译目的的因素有多个,译者只是其中一个因素。对标识牌译文误因之语外因素的分析,有助于调动和利用各种制约因素,形成一股社会合力,从而产出标准无误的标识牌译文。

  10. Event segmentation in a visual language: neural bases of processing American Sign Language predicates.

    Science.gov (United States)

    Malaia, Evie; Ranaweera, Ruwan; Wilbur, Ronnie B; Talavage, Thomas M

    2012-02-15

    Motion capture studies show that American Sign Language (ASL) signers distinguish end-points in telic verb signs by means of marked hand articulator motion, which rapidly decelerates to a stop at the end of these signs, as compared to atelic signs (Malaia and Wilbur, in press). Non-signers also show sensitivity to velocity in deceleration cues for event segmentation in visual scenes (Zacks et al., 2010; Zacks et al., 2006), introducing the question of whether the neural regions used by ASL signers for sign language verb processing might be similar to those used by non-signers for event segmentation. The present study investigated the neural substrate of predicate perception and linguistic processing in ASL. Observed patterns of activation demonstrate that Deaf signers process telic verb signs as having higher phonological complexity as compared to atelic verb signs. These results, together with previous neuroimaging data on spoken and sign languages (Shetreet et al., 2010; Emmorey et al., 2009), illustrate a route for how a prominent perceptual-kinematic feature used for non-linguistic event segmentation might come to be processed as an abstract linguistic feature due to sign language exposure.

  11. Perceptual organization in computer vision - A review and a proposal for a classificatory structure

    Science.gov (United States)

    Sarkar, Sudeep; Boyer, Kim L.

    1993-01-01

    The evolution of perceptual organization in biological vision, and its necessity in advanced computer vision systems, arises from the characteristic that perception, the extraction of meaning from sensory input, is an intelligent process. This is particularly so for high order organisms and, analogically, for more sophisticated computational models. The role of perceptual organization in computer vision systems is explored. This is done from four vantage points. First, a brief history of perceptual organization research in both humans and computer vision is offered. Next, a classificatory structure in which to cast perceptual organization research to clarify both the nomenclature and the relationships among the many contributions is proposed. Thirdly, the perceptual organization work in computer vision in the context of this classificatory structure is reviewed. Finally, the array of computational techniques applied to perceptual organization problems in computer vision is surveyed.

  12. Perceptual organization in computer vision - A review and a proposal for a classificatory structure

    Science.gov (United States)

    Sarkar, Sudeep; Boyer, Kim L.

    1993-01-01

    The evolution of perceptual organization in biological vision, and its necessity in advanced computer vision systems, arises from the characteristic that perception, the extraction of meaning from sensory input, is an intelligent process. This is particularly so for high order organisms and, analogically, for more sophisticated computational models. The role of perceptual organization in computer vision systems is explored. This is done from four vantage points. First, a brief history of perceptual organization research in both humans and computer vision is offered. Next, a classificatory structure in which to cast perceptual organization research to clarify both the nomenclature and the relationships among the many contributions is proposed. Thirdly, the perceptual organization work in computer vision in the context of this classificatory structure is reviewed. Finally, the array of computational techniques applied to perceptual organization problems in computer vision is surveyed.

  13. Perceptual consequences of disrupted auditory nerve activity.

    Science.gov (United States)

    Zeng, Fan-Gang; Kong, Ying-Yee; Michalewski, Henry J; Starr, Arnold

    2005-06-01

    Perceptual consequences of disrupted auditory nerve activity were systematically studied in 21 subjects who had been clinically diagnosed with auditory neuropathy (AN), a recently defined disorder characterized by normal outer hair cell function but disrupted auditory nerve function. Neurological and electrophysical evidence suggests that disrupted auditory nerve activity is due to desynchronized or reduced neural activity or both. Psychophysical measures showed that the disrupted neural activity has minimal effects on intensity-related perception, such as loudness discrimination, pitch discrimination at high frequencies, and sound localization using interaural level differences. In contrast, the disrupted neural activity significantly impairs timing related perception, such as pitch discrimination at low frequencies, temporal integration, gap detection, temporal modulation detection, backward and forward masking, signal detection in noise, binaural beats, and sound localization using interaural time differences. These perceptual consequences are the opposite of what is typically observed in cochlear-impaired subjects who have impaired intensity perception but relatively normal temporal processing after taking their impaired intensity perception into account. These differences in perceptual consequences between auditory neuropathy and cochlear damage suggest the use of different neural codes in auditory perception: a suboptimal spike count code for intensity processing, a synchronized spike code for temporal processing, and a duplex code for frequency processing. We also proposed two underlying physiological models based on desynchronized and reduced discharge in the auditory nerve to successfully account for the observed neurological and behavioral data. These methods and measures cannot differentiate between these two AN models, but future studies using electric stimulation of the auditory nerve via a cochlear implant might. These results not only show the unique

  14. Perceptual Plasticity for Auditory Object Recognition

    Directory of Open Access Journals (Sweden)

    Shannon L. M. Heald

    2017-05-01

    Full Text Available In our auditory environment, we rarely experience the exact acoustic waveform twice. This is especially true for communicative signals that have meaning for listeners. In speech and music, the acoustic signal changes as a function of the talker (or instrument, speaking (or playing rate, and room acoustics, to name a few factors. Yet, despite this acoustic variability, we are able to recognize a sentence or melody as the same across various kinds of acoustic inputs and determine meaning based on listening goals, expectations, context, and experience. The recognition process relates acoustic signals to prior experience despite variability in signal-relevant and signal-irrelevant acoustic properties, some of which could be considered as “noise” in service of a recognition goal. However, some acoustic variability, if systematic, is lawful and can be exploited by listeners to aid in recognition. Perceivable changes in systematic variability can herald a need for listeners to reorganize perception and reorient their attention to more immediately signal-relevant cues. This view is not incorporated currently in many extant theories of auditory perception, which traditionally reduce psychological or neural representations of perceptual objects and the processes that act on them to static entities. While this reduction is likely done for the sake of empirical tractability, such a reduction may seriously distort the perceptual process to be modeled. We argue that perceptual representations, as well as the processes underlying perception, are dynamically determined by an interaction between the uncertainty of the auditory signal and constraints of context. This suggests that the process of auditory recognition is highly context-dependent in that the identity of a given auditory object may be intrinsically tied to its preceding context. To argue for the flexible neural and psychological updating of sound-to-meaning mappings across speech and music, we

  15. Perceptual Biases in Relation to Paranormal and Conspiracy Beliefs.

    Directory of Open Access Journals (Sweden)

    Michiel van Elk

    Full Text Available Previous studies have shown that one's prior beliefs have a strong effect on perceptual decision-making and attentional processing. The present study extends these findings by investigating how individual differences in paranormal and conspiracy beliefs are related to perceptual and attentional biases. Two field studies were conducted in which visitors of a paranormal conducted a perceptual decision making task (i.e. the face/house categorization task; Experiment 1 or a visual attention task (i.e. the global/local processing task; Experiment 2. In the first experiment it was found that skeptics compared to believers more often incorrectly categorized ambiguous face stimuli as representing a house, indicating that disbelief rather than belief in the paranormal is driving the bias observed for the categorization of ambiguous stimuli. In the second experiment, it was found that skeptics showed a classical 'global-to-local' interference effect, whereas believers in conspiracy theories were characterized by a stronger 'local-to-global interference effect'. The present study shows that individual differences in paranormal and conspiracy beliefs are associated with perceptual and attentional biases, thereby extending the growing body of work in this field indicating effects of cultural learning on basic perceptual processes.

  16. Perceptual Biases in Relation to Paranormal and Conspiracy Beliefs.

    Science.gov (United States)

    van Elk, Michiel

    2015-01-01

    Previous studies have shown that one's prior beliefs have a strong effect on perceptual decision-making and attentional processing. The present study extends these findings by investigating how individual differences in paranormal and conspiracy beliefs are related to perceptual and attentional biases. Two field studies were conducted in which visitors of a paranormal conducted a perceptual decision making task (i.e. the face/house categorization task; Experiment 1) or a visual attention task (i.e. the global/local processing task; Experiment 2). In the first experiment it was found that skeptics compared to believers more often incorrectly categorized ambiguous face stimuli as representing a house, indicating that disbelief rather than belief in the paranormal is driving the bias observed for the categorization of ambiguous stimuli. In the second experiment, it was found that skeptics showed a classical 'global-to-local' interference effect, whereas believers in conspiracy theories were characterized by a stronger 'local-to-global interference effect'. The present study shows that individual differences in paranormal and conspiracy beliefs are associated with perceptual and attentional biases, thereby extending the growing body of work in this field indicating effects of cultural learning on basic perceptual processes.

  17. Perceptual learning of interrupted speech.

    Directory of Open Access Journals (Sweden)

    Michel Ruben Benard

    Full Text Available The intelligibility of periodically interrupted speech improves once the silent gaps are filled with noise bursts. This improvement has been attributed to phonemic restoration, a top-down repair mechanism that helps intelligibility of degraded speech in daily life. Two hypotheses were investigated using perceptual learning of interrupted speech. If different cognitive processes played a role in restoring interrupted speech with and without filler noise, the two forms of speech would be learned at different rates and with different perceived mental effort. If the restoration benefit were an artificial outcome of using the ecologically invalid stimulus of speech with silent gaps, this benefit would diminish with training. Two groups of normal-hearing listeners were trained, one with interrupted sentences with the filler noise, and the other without. Feedback was provided with the auditory playback of the unprocessed and processed sentences, as well as the visual display of the sentence text. Training increased the overall performance significantly, however restoration benefit did not diminish. The increase in intelligibility and the decrease in perceived mental effort were relatively similar between the groups, implying similar cognitive mechanisms for the restoration of the two types of interruptions. Training effects were generalizable, as both groups improved their performance also with the other form of speech than that they were trained with, and retainable. Due to null results and relatively small number of participants (10 per group, further research is needed to more confidently draw conclusions. Nevertheless, training with interrupted speech seems to be effective, stimulating participants to more actively and efficiently use the top-down restoration. This finding further implies the potential of this training approach as a rehabilitative tool for hearing-impaired/elderly populations.

  18. Auditory perceptual load: A review.

    Science.gov (United States)

    Murphy, Sandra; Spence, Charles; Dalton, Polly

    2017-02-08

    Selective attention is a crucial mechanism in everyday life, allowing us to focus on a portion of incoming sensory information at the expense of other less relevant stimuli. The circumstances under which irrelevant stimuli are successfully ignored have been a topic of scientific interest for several decades now. Over the last 20 years, the perceptual load theory (e.g. Lavie, 1995) has provided one robust framework for understanding these effects within the visual modality. The suggestion is that successful selection depends on the perceptual demands imposed by the task-relevant information. However, less research has addressed the question of whether the same principles hold in audition and, to date, the existing literature provides a mixed picture. Here, we review the evidence for and against the applicability of perceptual load theory in hearing, concluding that this question still awaits resolution.

  19. Perceptual dimensions of style in paintings

    Directory of Open Access Journals (Sweden)

    Marković Slobodan

    2007-01-01

    Full Text Available The main purpose of this study is to specify the basic perceptual dimensions underlying the judgments of the physical features which define the style in paintings (e.g. salient form, colorful surface, oval contours etc.. The other aim of the study is to correlate these dimensions with the subjective (affective dimensions of the experience of paintings. In the preliminary study a set of 25 pairs of elementary perceptual descriptors were empirically specified, and a set of 25 bipolar scales were made (e.g. uncolored-multicolored. In the experiment 30 subjects judged 24 paintings (paintings were taken from the study of Radonjić and Marković, 2004 on 25 scales. Factor analysis revealed the four factors: form (scales: precise, neat, salient form etc., color (color contrast, lightness contrast, vivid colors, space (voluminosity, depth and oval contours and complexity (multicolored, ornate, detailed. Obtained factors reflected the nature of the phenomenological and neural segregation of form, color, depth processing, and partially of complexity processing (e.g. spatial frequency processing within both the form and color subsystem. The aim of the next step of analysis was to specify the correlations between two groups of judgments: (a mean judgments of 24 paintings on perceptual factors and (b mean judgments of the same set of 24 paintings on subjective (affective experience factors, i.e. regularity, attraction, arousal and relaxation (judgments taken from Radonjić and Marković, 2005. The following significant correlations were obtained: regularity-form, regularity-space, attraction-form and arousal-complexity (negative correlation. The reasons for the unexpected negative correlation between arousal and complexity should be specified in further studies.

  20. Perceptual incongruence influences bistability and cortical activation

    NARCIS (Netherlands)

    Brouwer, G.J.; Tong, F.; Hagoort, P.; van Ee, R.

    2009-01-01

    We employed a parametric psychophysical design in combination with functional imaging to examine the influence of metric changes in perceptual incongruence on perceptual alternation rates and cortical responses. Subjects viewed a bistable stimulus defined by incongruent depth cues; bistability

  1. Perceptual averaging in individuals with Autism Spectrum Disorder

    Directory of Open Access Journals (Sweden)

    Jennifer Elise Corbett

    2016-11-01

    Full Text Available There is mounting evidence that observers rely on statistical summaries of visual information to maintain stable and coherent perception. Sensitivity to the mean (or other prototypical value of a visual feature (e.g., mean size appears to be a pervasive process in human visual perception. Previous studies in individuals diagnosed with Autism Spectrum Disorder (ASD have uncovered characteristic patterns of visual processing that suggest they may rely more on enhanced local representations of individual objects instead of computing such perceptual averages. To further explore the fundamental nature of abstract statistical representation in visual perception, we investigated perceptual averaging of mean size in a group of 12 high-functioning individuals diagnosed with ASD using simplified versions of two identification and adaptation tasks that elicited characteristic perceptual averaging effects in a control group of neurotypical participants. In Experiment 1, participants performed with above chance accuracy in recalling the mean size of a set of circles (mean task despite poor accuracy in recalling individual circle sizes (member task. In Experiment 2, their judgments of single circle size were biased by mean size adaptation. Overall, these results suggest that individuals with ASD perceptually average information about sets of objects in the surrounding environment. Our results underscore the fundamental nature of perceptual averaging in vision, and further our understanding of how autistic individuals make sense of the external environment.

  2. ‘If you are good, I get better’: the role of social hierarchy in perceptual decision-making

    Science.gov (United States)

    Pannunzi, Mario; Ayneto, Alba; Deco, Gustavo; Sebastián-Gallés, Nuria

    2014-01-01

    So far, it was unclear if social hierarchy could influence sensory or perceptual cognitive processes. We evaluated the effects of social hierarchy on these processes using a basic visual perceptual decision task. We constructed a social hierarchy where participants performed the perceptual task separately with two covertly simulated players (superior, inferior). Participants were faster (better) when performing the discrimination task with the superior player. We studied the time course when social hierarchy was processed using event-related potentials and observed hierarchical effects even in early stages of sensory-perceptual processing, suggesting early top–down modulation by social hierarchy. Moreover, in a parallel analysis, we fitted a drift-diffusion model (DDM) to the results to evaluate the decision making process of this perceptual task in the context of a social hierarchy. Consistently, the DDM pointed to nondecision time (probably perceptual encoding) as the principal period influenced by social hierarchy. PMID:23946003

  3. Subjective Confidence in Perceptual Judgments: A Test of the Self-Consistency Model

    Science.gov (United States)

    Koriat, Asher

    2011-01-01

    Two questions about subjective confidence in perceptual judgments are examined: the bases for these judgments and the reasons for their accuracy. Confidence in perceptual judgments has been claimed to rest on qualitatively different processes than confidence in memory tasks. However, predictions from a self-consistency model (SCM), which had been…

  4. Subjective Confidence in Perceptual Judgments: A Test of the Self-Consistency Model

    Science.gov (United States)

    Koriat, Asher

    2011-01-01

    Two questions about subjective confidence in perceptual judgments are examined: the bases for these judgments and the reasons for their accuracy. Confidence in perceptual judgments has been claimed to rest on qualitatively different processes than confidence in memory tasks. However, predictions from a self-consistency model (SCM), which had been…

  5. Perceptual Fading without Retinal Adaptation

    Science.gov (United States)

    Hsieh, Po-Jang; Colas, Jaron T.

    2012-01-01

    A retinally stabilized object readily undergoes perceptual fading and disappears from consciousness. This startling phenomenon is commonly believed to arise from local bottom-up sensory adaptation to edge information that occurs early in the visual pathway, such as in the lateral geniculate nucleus of the thalamus or retinal ganglion cells. Here…

  6. Perceptual transparency from image deformation.

    Science.gov (United States)

    Kawabe, Takahiro; Maruya, Kazushi; Nishida, Shin'ya

    2015-08-18

    Human vision has a remarkable ability to perceive two layers at the same retinal locations, a transparent layer in front of a background surface. Critical image cues to perceptual transparency, studied extensively in the past, are changes in luminance or color that could be caused by light absorptions and reflections by the front layer, but such image changes may not be clearly visible when the front layer consists of a pure transparent material such as water. Our daily experiences with transparent materials of this kind suggest that an alternative potential cue of visual transparency is image deformations of a background pattern caused by light refraction. Although previous studies have indicated that these image deformations, at least static ones, play little role in perceptual transparency, here we show that dynamic image deformations of the background pattern, which could be produced by light refraction on a moving liquid's surface, can produce a vivid impression of a transparent liquid layer without the aid of any other visual cues as to the presence of a transparent layer. Furthermore, a transparent liquid layer perceptually emerges even from a randomly generated dynamic image deformation as long as it is similar to real liquid deformations in its spatiotemporal frequency profile. Our findings indicate that the brain can perceptually infer the presence of "invisible" transparent liquids by analyzing the spatiotemporal structure of dynamic image deformation, for which it uses a relatively simple computation that does not require high-level knowledge about the detailed physics of liquid deformation.

  7. PERCEPTUAL CONSTANCY AND CONTEXTUAL ENHANCEMENT CONSTANCIA PERCEPTUAL Y MEJORAMIENTO CONTEXTUAL

    Directory of Open Access Journals (Sweden)

    HERIBERTO AVELINO

    2010-01-01

    Full Text Available The perception of the acoustic world surrounding us very often is different from its physical properties. Our mental representation of the sounds that we are exposed to are not in a one to one correspondence with the sounds we sense. Auditory objects and their environments are categorized and loaded in memory so that recognition of complex dynamic scenes are perceived optimally. Precise identification of voices and linguistic objects are crucial for effective communication. However, the normal context of hearing contains multiple, competing and noisy sources. In such disadvantageous conditions the identity of the percepts is more efficient if they are stored in memory. The results of the present study offer experimental evidence that high-level cognitive processes might constrain basic auditory mechanisms involved in identifying phonemic tone to guarantee perceptual constancy. The results showing a better identification of tones in contexts that are inveresely proportional to their frequency support the idea that peripheral auditory processing enhances the identification of the tones by a general function of contextual contrast.La percepción del mundo acústico que nos rodea es a menudo diferente de sus propiedades físicas. Nuestra representación mental de los sonidos a los que estamos expuestos no están en una correspondencia unívoca con los sonidos que sentimos. Los objetos auditivos y sus contextos son categorizados y acumulados en la memoria de forma tal que el reconocimiento de escenas dinámicas complejas son percibidas óptimamente. La identificación precisa de voces y objetos lingüísticos son cruciales para la comunicación efectiva. Sin embargo, el contexto normal de la escucha contiene fuentes múltiples, con ruido y en competencia. En estas condiciones de desventaja la identidad de los perceptos es más eficiente si son almacenados en la memoria. Los resultados del presente estudio ofrecen evidencia experimental de que

  8. Neural mechanisms underlying the induction and relief of perceptual curiosity

    Directory of Open Access Journals (Sweden)

    Marieke eJepma

    2012-02-01

    Full Text Available Curiosity is one of the most basic biological drives in both animals and humans, and has been identified as a key motive for learning and discovery. Despite the importance of curiosity and related behaviors, the topic has been largely neglected in human neuroscience; hence little is known about the neurobiological mechanisms underlying curiosity. We used functional magnetic resonance imaging (fMRI to investigate what happens in our brain during the induction and subsequent relief of perceptual curiosity. Our core findings were that (i the induction of perceptual curiosity, through the presentation of ambiguous visual input, activated the anterior insula and anterior cingulate cortex, brain regions sensitive to conflict and arousal; (ii the relief of perceptual curiosity, through visual disambiguation, activated regions of the striatum that have been related to reward processing; and (iii the relief of perceptual curiosity was associated with hippocampal activation and enhanced incidental memory. These findings provide the first demonstration of the neural basis of human perceptual curiosity. Our results provide neurobiological support for a classic psychological theory of curiosity, which holds that curiosity is an aversive condition of increased arousal whose termination is rewarding and facilitates memory.

  9. Neural mechanisms underlying the induction and relief of perceptual curiosity.

    Science.gov (United States)

    Jepma, Marieke; Verdonschot, Rinus G; van Steenbergen, Henk; Rombouts, Serge A R B; Nieuwenhuis, Sander

    2012-01-01

    Curiosity is one of the most basic biological drives in both animals and humans, and has been identified as a key motive for learning and discovery. Despite the importance of curiosity and related behaviors, the topic has been largely neglected in human neuroscience; hence little is known about the neurobiological mechanisms underlying curiosity. We used functional magnetic resonance imaging (fMRI) to investigate what happens in our brain during the induction and subsequent relief of perceptual curiosity. Our core findings were that (1) the induction of perceptual curiosity, through the presentation of ambiguous visual input, activated the anterior insula and anterior cingulate cortex (ACC), brain regions sensitive to conflict and arousal; (2) the relief of perceptual curiosity, through visual disambiguation, activated regions of the striatum that have been related to reward processing; and (3) the relief of perceptual curiosity was associated with hippocampal activation and enhanced incidental memory. These findings provide the first demonstration of the neural basis of human perceptual curiosity. Our results provide neurobiological support for a classic psychological theory of curiosity, which holds that curiosity is an aversive condition of increased arousal whose termination is rewarding and facilitates memory.

  10. Neural mechanisms underlying the induction and relief of perceptual curiosity

    Science.gov (United States)

    Jepma, Marieke; Verdonschot, Rinus G.; van Steenbergen, Henk; Rombouts, Serge A. R. B.; Nieuwenhuis, Sander

    2012-01-01

    Curiosity is one of the most basic biological drives in both animals and humans, and has been identified as a key motive for learning and discovery. Despite the importance of curiosity and related behaviors, the topic has been largely neglected in human neuroscience; hence little is known about the neurobiological mechanisms underlying curiosity. We used functional magnetic resonance imaging (fMRI) to investigate what happens in our brain during the induction and subsequent relief of perceptual curiosity. Our core findings were that (1) the induction of perceptual curiosity, through the presentation of ambiguous visual input, activated the anterior insula and anterior cingulate cortex (ACC), brain regions sensitive to conflict and arousal; (2) the relief of perceptual curiosity, through visual disambiguation, activated regions of the striatum that have been related to reward processing; and (3) the relief of perceptual curiosity was associated with hippocampal activation and enhanced incidental memory. These findings provide the first demonstration of the neural basis of human perceptual curiosity. Our results provide neurobiological support for a classic psychological theory of curiosity, which holds that curiosity is an aversive condition of increased arousal whose termination is rewarding and facilitates memory. PMID:22347853

  11. To What Extent Do We Hear Phonemic Contrasts in a Non-Native Regional Variety? Tracking the Dynamics of Perceptual Processing with EEG

    Science.gov (United States)

    Dufour, Sophie; Brunelliere, Angele; Nguyen, Noel

    2013-01-01

    This combined ERP and behavioral experiment explores the dynamics of processing during the discrimination of vowels in a non-native regional variety. Southern listeners were presented with three word forms, two of which are encountered in both Standard and Southern French ([kot] and [kut]), whereas the third one exists in Standard but not Southern…

  12. The "Perceptual Wedge Hypothesis" as the Basis for Bilingual Babies' Phonetic Processing Advantage: New insights from fNIRS Brain Imaging

    Science.gov (United States)

    Petitto, L. A.; Berens, M. S.; Kovelman, I.; Dubins, M. H.; Jasinska, K.; Shalinsky, M.

    2012-01-01

    In a neuroimaging study focusing on young bilinguals, we explored the brains of bilingual and monolingual babies across two age groups (younger 4-6 months, older 10-12 months), using fNIRS in a new event-related design, as babies processed linguistic phonetic (Native English, Non-Native Hindi) and nonlinguistic Tone stimuli. We found that phonetic…

  13. Toward a Perceptual-Span Theory of Distributed Processing in Reading: A Reply to Rayner, Pollatsek, Drieghe, Slattery, and Reichle (2007)

    Science.gov (United States)

    Kliegl, Reinhold

    2007-01-01

    K. Rayner, A. Pollatsek, D. Drieghe, T. J. Slattery, and E. D. Reichle argued that the R. Kliegl, A. Nuthmann, and R. Engbert corpus-analytic evidence for distributed processing during reading should not be accepted because (a) there might be problems of multicollinearity, (b) the distinction between content and function words and the skipping…

  14. Development of Visual Design Process of Clothing Sales Web Page Based on Perceptual Engineering%基于感性工学的服装销售网页视觉设计流程开发

    Institute of Scientific and Technical Information of China (English)

    侯倩

    2015-01-01

    Network sales have increasingly become an important way of enterprise image display and sales. It becomes a design issue of concern that enhancing the visual appeal of the web page rapidly and accurately. So, by collecting and analyzing existing research results, the article formed the development ideas of the visual design process of clothing sales web page based on the perceptual engineering. From the demands of consumers and sellers, the article set up the principle of the process development, established the constructing points, and ifnally completed the process building, to offer methods and theoretical references for the relevant design practice and further research.%网络销售越来越成为企业展示形象和销售的重要途径,快速准确地增强网页视觉吸引力成为备受关注的设计问题。因此本文整理与分析了已有研究成果,形成了基于感性工学的服装销售网页视觉设计流程的构建思路,并从消费者与销售者双方诉求入手,树立了流程开发的原则,明确了构建要点,最终完成了流程的构建,以期为相关设计实践与深入研究提供方法借鉴和理论支撑。

  15. Nicotine facilitates memory consolidation in perceptual learning.

    Science.gov (United States)

    Beer, Anton L; Vartak, Devavrat; Greenlee, Mark W

    2013-01-01

    Perceptual learning is a special type of non-declarative learning that involves experience-dependent plasticity in sensory cortices. The cholinergic system is known to modulate declarative learning. In particular, reduced levels or efficacy of the neurotransmitter acetylcholine were found to facilitate declarative memory consolidation. However, little is known about the role of the cholinergic system in memory consolidation of non-declarative learning. Here we compared two groups of non-smoking men who learned a visual texture discrimination task (TDT). One group received chewing tobacco containing nicotine for 1 h directly following the TDT training. The other group received a similar tasting control substance without nicotine. Electroencephalographic recordings during substance consumption showed reduced alpha activity and P300 latencies in the nicotine group compared to the control group. When re-tested on the TDT the following day, both groups responded more accurately and more rapidly than during training. These improvements were specific to the retinal location and orientation of the texture elements of the TDT suggesting that learning involved early visual cortex. A group comparison showed that learning effects were more pronounced in the nicotine group than in the control group. These findings suggest that oral consumption of nicotine enhances the efficacy of nicotinic acetylcholine receptors. Our findings further suggest that enhanced efficacy of the cholinergic system facilitates memory consolidation in perceptual learning (and possibly other types of non-declarative learning). In that regard acetylcholine seems to affect consolidation processes in perceptual learning in a different manner than in declarative learning. Alternatively, our findings might reflect dose-dependent cholinergic modulation of memory consolidation. This article is part of a Special Issue entitled 'Cognitive Enhancers'.

  16. Perceptual learning: toward a comprehensive theory.

    Science.gov (United States)

    Watanabe, Takeo; Sasaki, Yuka

    2015-01-03

    Visual perceptual learning (VPL) is long-term performance increase resulting from visual perceptual experience. Task-relevant VPL of a feature results from training of a task on the feature relevant to the task. Task-irrelevant VPL arises as a result of exposure to the feature irrelevant to the trained task. At least two serious problems exist. First, there is the controversy over which stage of information processing is changed in association with task-relevant VPL. Second, no model has ever explained both task-relevant and task-irrelevant VPL. Here we propose a dual plasticity model in which feature-based plasticity is a change in a representation of the learned feature, and task-based plasticity is a change in processing of the trained task. Although the two types of plasticity underlie task-relevant VPL, only feature-based plasticity underlies task-irrelevant VPL. This model provides a new comprehensive framework in which apparently contradictory results could be explained.

  17. The Impact of Perceptual Load on Emotional Face Processing in Attentional Blink Paradigm%注意瞬脱范式中的知觉负载对情绪面孔加工的影响

    Institute of Scientific and Technical Information of China (English)

    叶榕; 余凤琼; 蒋玉宝; 汪凯

    2011-01-01

    情绪性刺激的加工是否受注意影响目前尚存争论.基于许多操纵空间注意焦点的研究未能在注意资源的分配上进行精确的调节,本实验将时间维度的注意瞬脱范式与负载理论相结合,通过调节注意瞬脱中T1刺激物知觉负载水平的高低(箭头朝向相同与否),观察被试在四种时间延迟条件下(延迟2,延迟3,延迟5,延迟8)T2目标侦测任务恐惧和中性面孔的反应正确率,从而对情绪性刺激的加工特征进行研究.实验发现:对恐惧面孔侦测的正确率在高知觉负载条件下显著降低,而中性面孔则不受知觉负载水平影响,并且这种高知觉负载对恐惧面孔加工的抑制作用仅发生在注意瞬脱中的短延迟条件下.说明在知觉加工资源和注意调节作用同时受限的情况下恐惧面孔的优势加工受到限制,提示情绪性刺激的加工与中性刺激相比消耗的加工资源较少,并依赖于注意的调控.%The processing of emotion-laden stimuli is often proposed to take place in a prioritized and obligatory fashion. The evidences from both electrophysiological and neuroimaging studies in which the spatial focus of attention is explicitly manipulated have showed controversial results on the subject of whether attention is required for emotional stimuli processing. Although this issue can be partially reconciled by adapting the concept of attentional load, the manipulation of attentional resources may not be subtle enough to effectively restrain the privileged processing of emotional stimuli. The present study is aim to further investigate the mechanism of emotion processing by combining the Load Theory and attentional blink (AB) paradigm. We hypothesize that in attentional blink paradigm the prioritized processing of emotional T2 stimuli may be suppressed by the double limitation of increased T1 perceptual load and short latency of T1-T2 interval.In present study. each trial consisted of a first target (T1

  18. Out of mind, out of sight: perceptual consequences of memory suppression.

    Science.gov (United States)

    Kim, Kyungmi; Yi, Do-Joon

    2013-04-01

    In the present study, the effect of memory suppression on subsequent perceptual processing of visual objects was examined within a modified think/no-think paradigm. Suppressing memories of visual objects significantly impaired subsequent perceptual identification of those objects when they were briefly encountered (Experiment 1) and when they were presented in noise (Experiment 2), relative to performance on baseline items for which participants did not undergo suppression training. However, in Experiment 3, when perceptual identification was performed on mirror-reversed images of to-be-suppressed objects, no impairment was observed. These findings, analogous to those showing forgetting of suppressed words in long-term memory, suggest that suppressing memories of visual objects might be mediated by direct inhibition of perceptual representations, which, in turn, impairs later perception of them. This study provides strong support for the role of inhibitory mechanisms in memory control and suggests a tight link between higher-order cognitive operations and perceptual processing.

  19. Where’s Waldo? How perceptual, cognitive, and emotional brain processes cooperate during learning to categorize and find desired objects in a cluttered scene

    Science.gov (United States)

    Chang, Hung-Cheng; Grossberg, Stephen; Cao, Yongqiang

    2014-01-01

    The Where’s Waldo problem concerns how individuals can rapidly learn to search a scene to detect, attend, recognize, and look at a valued target object in it. This article develops the ARTSCAN Search neural model to clarify how brain mechanisms across the What and Where cortical streams are coordinated to solve the Where’s Waldo problem. The What stream learns positionally-invariant object representations, whereas the Where stream controls positionally-selective spatial and action representations. The model overcomes deficiencies of these computationally complementary properties through What and Where stream interactions. Where stream processes of spatial attention and predictive eye movement control modulate What stream processes whereby multiple view- and positionally-specific object categories are learned and associatively linked to view- and positionally-invariant object categories through bottom-up and attentive top-down interactions. Gain fields control the coordinate transformations that enable spatial attention and predictive eye movements to carry out this role. What stream cognitive-emotional learning processes enable the focusing of motivated attention upon the invariant object categories of desired objects. What stream cognitive names or motivational drives can prime a view- and positionally-invariant object category of a desired target object. A volitional signal can convert these primes into top-down activations that can, in turn, prime What stream view- and positionally-specific categories. When it also receives bottom-up activation from a target, such a positionally-specific category can cause an attentional shift in the Where stream to the positional representation of the target, and an eye movement can then be elicited to foveate it. These processes describe interactions among brain regions that include visual cortex, parietal cortex, inferotemporal cortex, prefrontal cortex (PFC), amygdala, basal ganglia (BG), and superior colliculus (SC

  20. Where's Waldo? How perceptual, cognitive, and emotional brain processes cooperate during learning to categorize and find desired objects in a cluttered scene.

    Science.gov (United States)

    Chang, Hung-Cheng; Grossberg, Stephen; Cao, Yongqiang

    2014-01-01

    The Where's Waldo problem concerns how individuals can rapidly learn to search a scene to detect, attend, recognize, and look at a valued target object in it. This article develops the ARTSCAN Search neural model to clarify how brain mechanisms across the What and Where cortical streams are coordinated to solve the Where's Waldo problem. The What stream learns positionally-invariant object representations, whereas the Where stream controls positionally-selective spatial and action representations. The model overcomes deficiencies of these computationally complementary properties through What and Where stream interactions. Where stream processes of spatial attention and predictive eye movement control modulate What stream processes whereby multiple view- and positionally-specific object categories are learned and associatively linked to view- and positionally-invariant object categories through bottom-up and attentive top-down interactions. Gain fields control the coordinate transformations that enable spatial attention and predictive eye movements to carry out this role. What stream cognitive-emotional learning processes enable the focusing of motivated attention upon the invariant object categories of desired objects. What stream cognitive names or motivational drives can prime a view- and positionally-invariant object category of a desired target object. A volitional signal can convert these primes into top-down activations that can, in turn, prime What stream view- and positionally-specific categories. When it also receives bottom-up activation from a target, such a positionally-specific category can cause an attentional shift in the Where stream to the positional representation of the target, and an eye movement can then be elicited to foveate it. These processes describe interactions among brain regions that include visual cortex, parietal cortex, inferotemporal cortex, prefrontal cortex (PFC), amygdala, basal ganglia (BG), and superior colliculus (SC).

  1. Referenceless Prediction of Perceptual Fog Density and Perceptual Image Defogging.

    Science.gov (United States)

    Choi, Lark Kwon; You, Jaehee; Bovik, Alan Conrad

    2015-11-01

    We propose a referenceless perceptual fog density prediction model based on natural scene statistics (NSS) and fog aware statistical features. The proposed model, called Fog Aware Density Evaluator (FADE), predicts the visibility of a foggy scene from a single image without reference to a corresponding fog-free image, without dependence on salient objects in a scene, without side geographical camera information, without estimating a depth-dependent transmission map, and without training on human-rated judgments. FADE only makes use of measurable deviations from statistical regularities observed in natural foggy and fog-free images. Fog aware statistical features that define the perceptual fog density index derive from a space domain NSS model and the observed characteristics of foggy images. FADE not only predicts perceptual fog density for the entire image, but also provides a local fog density index for each patch. The predicted fog density using FADE correlates well with human judgments of fog density taken in a subjective study on a large foggy image database. As applications, FADE not only accurately assesses the performance of defogging algorithms designed to enhance the visibility of foggy images, but also is well suited for image defogging. A new FADE-based referenceless perceptual image defogging, dubbed DEnsity of Fog Assessment-based DEfogger (DEFADE) achieves better results for darker, denser foggy images as well as on standard foggy images than the state of the art defogging methods. A software release of FADE and DEFADE is available online for public use: http://live.ece.utexas.edu/research/fog/index.html.

  2. Perceptual learning modifies the functional specializations of visual cortical areas.

    Science.gov (United States)

    Chen, Nihong; Cai, Peng; Zhou, Tiangang; Thompson, Benjamin; Fang, Fang

    2016-05-17

    Training can improve performance of perceptual tasks. This phenomenon, known as perceptual learning, is strongest for the trained task and stimulus, leading to a widely accepted assumption that the associated neuronal plasticity is restricted to brain circuits that mediate performance of the trained task. Nevertheless, learning does transfer to other tasks and stimuli, implying the presence of more widespread plasticity. Here, we trained human subjects to discriminate the direction of coherent motion stimuli. The behavioral learning effect substantially transferred to noisy motion stimuli. We used transcranial magnetic stimulation (TMS) and functional magnetic resonance imaging (fMRI) to investigate the neural mechanisms underlying the transfer of learning. The TMS experiment revealed dissociable, causal contributions of V3A (one of the visual areas in the extrastriate visual cortex) and MT+ (middle temporal/medial superior temporal cortex) to coherent and noisy motion processing. Surprisingly, the contribution of MT+ to noisy motion processing was replaced by V3A after perceptual training. The fMRI experiment complemented and corroborated the TMS finding. Multivariate pattern analysis showed that, before training, among visual cortical areas, coherent and noisy motion was decoded most accurately in V3A and MT+, respectively. After training, both kinds of motion were decoded most accurately in V3A. Our findings demonstrate that the effects of perceptual learning extend far beyond the retuning of specific neural populations for the trained stimuli. Learning could dramatically modify the inherent functional specializations of visual cortical areas and dynamically reweight their contributions to perceptual decisions based on their representational qualities. These neural changes might serve as the neural substrate for the transfer of perceptual learning.

  3. Perceptual conflict during sensorimotor integration processes - a neurophysiological study in response inhibition.

    Science.gov (United States)

    Chmielewski, Witold X; Beste, Christian

    2016-05-25

    A multitude of sensory inputs needs to be processed during sensorimotor integration. A crucial factor for detecting relevant information is its complexity, since information content can be conflicting at a perceptual level. This may be central to executive control processes, such as response inhibition. This EEG study aims to investigate the system neurophysiological mechanisms behind effects of perceptual conflict on response inhibition. We systematically modulated perceptual conflict by integrating a Global-local task with a Go/Nogo paradigm. The results show that conflicting perceptual information, in comparison to non-conflicting perceptual information, impairs response inhibition performance. This effect was evident regardless of whether the relevant information for response inhibition is displayed on the global, or local perceptual level. The neurophysiological data suggests that early perceptual/ attentional processing stages do not underlie these modulations. Rather, processes at the response selection level (P3), play a role in changed response inhibition performance. This conflict-related impairment of inhibitory processes is associated with activation differences in (inferior) parietal areas (BA7 and BA40) and not as commonly found in the medial prefrontal areas. This suggests that various functional neuroanatomical structures may mediate response inhibition and that the functional neuroanatomical structures involved depend on the complexity of sensory integration processes.

  4. Perceptual Adaptation of Voice Gender Discrimination with Spectrally Shifted Vowels

    Science.gov (United States)

    Li, Tianhao; Fu, Qian-Jie

    2011-01-01

    Purpose: To determine whether perceptual adaptation improves voice gender discrimination of spectrally shifted vowels and, if so, which acoustic cues contribute to the improvement. Method: Voice gender discrimination was measured for 10 normal-hearing subjects, during 5 days of adaptation to spectrally shifted vowels, produced by processing the…

  5. Prediction Error Associated with the Perceptual Segmentation of Naturalistic Events

    Science.gov (United States)

    Zacks, Jeffrey M.; Kurby, Christopher A.; Eisenberg, Michelle L.; Haroutunian, Nayiri

    2011-01-01

    Predicting the near future is important for survival and plays a central role in theories of perception, language processing, and learning. Prediction failures may be particularly important for initiating the updating of perceptual and memory systems and, thus, for the subjective experience of events. Here, we asked observers to make predictions…

  6. Identifying the dominating perceptual differences in headphone reproduction

    DEFF Research Database (Denmark)

    Volk, Christer Peter; Lavandier, Mathieu; Bech, Søren

    2016-01-01

    The perceptual differences between the sound reproductions of headphones were investigated in a pair-wise comparison study. Two musical excerpts were reproduced over 21 headphones positioned on a mannequin and recorded. The recordings were then processed and reproduced over one set of headphones...

  7. Cognitive-Perceptual Examination of Remediation Approaches to Hypokinetic Dysarthria

    Science.gov (United States)

    McAuliffe, Megan J.; Kerr, Sarah E.; Gibson, Elizabeth M. R.; Anderson, Tim; LaShell, Patrick J.

    2014-01-01

    Purpose: To determine how increased vocal loudness and reduced speech rate affect listeners' cognitive-perceptual processing of hypokinetic dysarthric speech associated with Parkinson's disease. Method: Fifty-one healthy listener participants completed a speech perception experiment. Listeners repeated phrases produced by 5 individuals…

  8. Effects of load and maintenance duration on the time course of information encoding and retrieval in working memory: from perceptual analysis to post-categorization processes.

    Directory of Open Access Journals (Sweden)

    Diego ePinal

    2014-04-01

    Full Text Available Working memory (WM involves three cognitive events: information encoding, maintenance and retrieval; these are supported by brain activity in a network of frontal, parietal and temporal regions. Manipulation of WM load and duration of the maintenance period can modulate this activity. Although such modulations have been widely studied using the ERP technique, a precise description of the time course of brain activity during encoding and retrieval is still required. Here, we used this technique and principal component analysis to assess the time course of brain activity during encoding and retrieval in a delayed match to sample task. We also investigated the effects of memory load and duration of the maintenance period on ERP activity. Brain activity was similar during information encoding and retrieval and comprised six temporal factors, which closely matched the latency and scalp distribution of some ERP components: P1, N1, P2, N2, P300 and a slow wave. Changes in memory load modulated task performance and yielded variations in frontal lobe activation. Moreover, the P300 amplitude was smaller in the high than in the low load condition during encoding and retrieval. Conversely, the slow wave amplitude was higher in the high than in the low load condition during encoding, and the same was true for the N2 amplitude during retrieval. Thus, during encoding, memory load appears to modulate the processing resources for context updating and post-categorization processes, and during retrieval it modulates resources for stimulus classification and context updating. Besides, despite the lack of differences in task performance related to duration of the maintenance period, larger N2 amplitude and stronger activation of the left temporal lobe after long than after short maintenance periods were found during information retrieval. Thus, results regarding the duration of maintenance period were complex, and future work is required to test the time-based decay

  9. Perceptual and cognitive spatial learning.

    Science.gov (United States)

    Bedford, F L

    1993-06-01

    Ss were taught novel mappings between visual space and motor space with either a variant on a prism adaptation paradigm (Experiments 1 and 2) or a nonperceptual cognitive task (Experiments 3 and 4). First, discrimination training specified that 1 visual location required a new pointing response but another location did not. This led to unusual generalization unlike typical generalization decrement. Second, training at 9 locations specified that 1 location required a new response but that the remaining 8 did not. This simple isolation mapping was unlearnable and instead a flat function fit through all of space. In contrast, for the cognitive paradigm, not only was isolation of one region of space easily learned, it was the preferred pattern of generalization. Implications for perceptual learning, as well as the qualitative distinctions between perceptual and cognitive learning, are discussed.

  10. Motivation and intelligence drive auditory perceptual learning.

    Directory of Open Access Journals (Sweden)

    Sygal Amitay

    Full Text Available BACKGROUND: Although feedback on performance is generally thought to promote perceptual learning, the role and necessity of feedback remain unclear. We investigated the effect of providing varying amounts of positive feedback while listeners attempted to discriminate between three identical tones on learning frequency discrimination. METHODOLOGY/PRINCIPAL FINDINGS: Using this novel procedure, the feedback was meaningless and random in relation to the listeners' responses, but the amount of feedback provided (or lack thereof affected learning. We found that a group of listeners who received positive feedback on 10% of the trials improved their performance on the task (learned, while other groups provided either with excess (90% or with no feedback did not learn. Superimposed on these group data, however, individual listeners showed other systematic changes of performance. In particular, those with lower non-verbal IQ who trained in the no feedback condition performed more poorly after training. CONCLUSIONS/SIGNIFICANCE: This pattern of results cannot be accounted for by learning models that ascribe an external teacher role to feedback. We suggest, instead, that feedback is used to monitor performance on the task in relation to its perceived difficulty, and that listeners who learn without the benefit of feedback are adept at self-monitoring of performance, a trait that also supports better performance on non-verbal IQ tests. These results show that 'perceptual' learning is strongly influenced by top-down processes of motivation and intelligence.

  11. Motivation and intelligence drive auditory perceptual learning.

    Science.gov (United States)

    Amitay, Sygal; Halliday, Lorna; Taylor, Jenny; Sohoglu, Ediz; Moore, David R

    2010-03-23

    Although feedback on performance is generally thought to promote perceptual learning, the role and necessity of feedback remain unclear. We investigated the effect of providing varying amounts of positive feedback while listeners attempted to discriminate between three identical tones on learning frequency discrimination. Using this novel procedure, the feedback was meaningless and random in relation to the listeners' responses, but the amount of feedback provided (or lack thereof) affected learning. We found that a group of listeners who received positive feedback on 10% of the trials improved their performance on the task (learned), while other groups provided either with excess (90%) or with no feedback did not learn. Superimposed on these group data, however, individual listeners showed other systematic changes of performance. In particular, those with lower non-verbal IQ who trained in the no feedback condition performed more poorly after training. This pattern of results cannot be accounted for by learning models that ascribe an external teacher role to feedback. We suggest, instead, that feedback is used to monitor performance on the task in relation to its perceived difficulty, and that listeners who learn without the benefit of feedback are adept at self-monitoring of performance, a trait that also supports better performance on non-verbal IQ tests. These results show that 'perceptual' learning is strongly influenced by top-down processes of motivation and intelligence.

  12. Perceptual learning during action video game playing.

    Science.gov (United States)

    Green, C Shawn; Li, Renjie; Bavelier, Daphne

    2010-04-01

    Action video games have been shown to enhance behavioral performance on a wide variety of perceptual tasks, from those that require effective allocation of attentional resources across the visual scene, to those that demand the successful identification of fleetingly presented stimuli. Importantly, these effects have not only been shown in expert action video game players, but a causative link has been established between action video game play and enhanced processing through training studies. Although an account based solely on attention fails to capture the variety of enhancements observed after action game playing, a number of models of perceptual learning are consistent with the observed results, with behavioral modeling favoring the hypothesis that avid video game players are better able to form templates for, or extract the relevant statistics of, the task at hand. This may suggest that the neural site of learning is in areas where information is integrated and actions are selected; yet changes in low-level sensory areas cannot be ruled out. Copyright © 2009 Cognitive Science Society, Inc.

  13. Perceptual Anomalies in Schizophrenia: Integrating Phenomenology and Cognitive Neuroscience

    Science.gov (United States)

    Uhlhaas, Peter J.; Mishara, Aaron L.

    2007-01-01

    From phenomenological and experimental perspectives, research in schizophrenia has emphasized deficits in “higher” cognitive functions, including attention, executive function, as well as memory. In contrast, general consensus has viewed dysfunctions in basic perceptual processes to be relatively unimportant in the explanation of more complex aspects of the disorder, including changes in self-experience and the development of symptoms such as delusions. We present evidence from phenomenology and cognitive neuroscience that changes in the perceptual field in schizophrenia may represent a core impairment. After introducing the phenomenological approach to perception (Husserl, the Gestalt School), we discuss the views of Paul Matussek, Klaus Conrad, Ludwig Binswanger, and Wolfgang Blankenburg on perception in schizophrenia. These 4 psychiatrists describe changes in perception and automatic processes that are related to the altered experience of self. The altered self-experience, in turn, may be responsible for the emergence of delusions. The phenomenological data are compatible with current research that conceptualizes dysfunctions in perceptual processing as a deficit in the ability to combine stimulus elements into coherent object representations. Relationships of deficits in perceptual organization to cognitive and social dysfunction as well as the possible neurobiological mechanisms are discussed. PMID:17118973

  14. Steady-state and dynamic network modes for perceptual expectation.

    Science.gov (United States)

    Choi, Uk-Su; Sung, Yul-Wan; Ogawa, Seiji

    2017-01-12

    Perceptual expectation can attenuate repetition suppression, the stimulus-induced neuronal response generated by repeated stimulation, suggesting that repetition suppression is a top-down modulatory phenomenon. However, it is still unclear which high-level brain areas are involved and how they interact with low-level brain areas. Further, the temporal range over which perceptual expectation can effectively attenuate repetition suppression effects remains unclear. To elucidate the details of this top-down modulatory process, we used two short and long inter-stimulus intervals for a perceptual expectation paradigm of paired stimulation. We found that top-down modulation enhanced the response to the unexpected stimulus when repetition suppression was weak and that the effect disappeared at 1,000 ms prior to stimulus exposure. The high-level areas involved in this process included the left inferior frontal gyrus (IFG_L) and left parietal lobule (IPL_L). We also found two systems providing modulatory input to the right fusiform face area (FFA_R): one from IFG_L and the other from IPL_L. Most importantly, we identified two states of networks through which perceptual expectation modulates sensory responses: one is a dynamic state and the other is a steady state. Our results provide the first functional magnetic resonance imaging (fMRI) evidence of temporally nested networks in brain processing.

  15. Perceptual anomalies in schizophrenia: integrating phenomenology and cognitive neuroscience.

    Science.gov (United States)

    Uhlhaas, Peter J; Mishara, Aaron L

    2007-01-01

    From phenomenological and experimental perspectives, research in schizophrenia has emphasized deficits in "higher" cognitive functions, including attention, executive function, as well as memory. In contrast, general consensus has viewed dysfunctions in basic perceptual processes to be relatively unimportant in the explanation of more complex aspects of the disorder, including changes in self-experience and the development of symptoms such as delusions. We present evidence from phenomenology and cognitive neuroscience that changes in the perceptual field in schizophrenia may represent a core impairment. After introducing the phenomenological approach to perception (Husserl, the Gestalt School), we discuss the views of Paul Matussek, Klaus Conrad, Ludwig Binswanger, and Wolfgang Blankenburg on perception in schizophrenia. These 4 psychiatrists describe changes in perception and automatic processes that are related to the altered experience of self. The altered self-experience, in turn, may be responsible for the emergence of delusions. The phenomenological data are compatible with current research that conceptualizes dysfunctions in perceptual processing as a deficit in the ability to combine stimulus elements into coherent object representations. Relationships of deficits in perceptual organization to cognitive and social dysfunction as well as the possible neurobiological mechanisms are discussed.

  16. Perceptual learning of degraded speech by minimizing prediction error.

    Science.gov (United States)

    Sohoglu, Ediz; Davis, Matthew H

    2016-03-22

    Human perception is shaped by past experience on multiple timescales. Sudden and dramatic changes in perception occur when prior knowledge or expectations match stimulus content. These immediate effects contrast with the longer-term, more gradual improvements that are characteristic of perceptual learning. Despite extensive investigation of these two experience-dependent phenomena, there is considerable debate about whether they result from common or dissociable neural mechanisms. Here we test single- and dual-mechanism accounts of experience-dependent changes in perception using concurrent magnetoencephalographic and EEG recordings of neural responses evoked by degraded speech. When speech clarity was enhanced by prior knowledge obtained from matching text, we observed reduced neural activity in a peri-auditory region of the superior temporal gyrus (STG). Critically, longer-term improvements in the accuracy of speech recognition following perceptual learning resulted in reduced activity in a nearly identical STG region. Moreover, short-term neural changes caused by prior knowledge and longer-term neural changes arising from perceptual learning were correlated across subjects with the magnitude of learning-induced changes in recognition accuracy. These experience-dependent effects on neural processing could be dissociated from the neural effect of hearing physically clearer speech, which similarly enhanced perception but increased rather than decreased STG responses. Hence, the observed neural effects of prior knowledge and perceptual learning cannot be attributed to epiphenomenal changes in listening effort that accompany enhanced perception. Instead, our results support a predictive coding account of speech perception; computational simulations show how a single mechanism, minimization of prediction error, can drive immediate perceptual effects of prior knowledge and longer-term perceptual learning of degraded speech.

  17. An integrative mechanistic account of psychological distress, therapeutic change and recovery: the Perceptual Control Theory approach.

    Science.gov (United States)

    Higginson, Sally; Mansell, Warren; Wood, Alex M

    2011-03-01

    The exact nature and mechanisms of psychological change within psychological disorders remain unknown. This review aims to use a psychological framework known as Perceptual Control Theory (Powers, 1973, 2005; Powers, Clark, & McFarland, 1960) to integrate the diverse literature within psychotherapy research. The core principles of Perceptual Control Theory are explained, and key domains of psychotherapy are considered to explore how well they converge with these principles. The quantitative and qualitative empirical literature on the process of psychological change is reviewed to examine how it fits with predictions based on Perceptual Control Theory. Furthermore, the prerequisites for psychological change; client qualities, therapist qualities, the therapeutic alliance and the shifting of awareness, are also considered to examine their consistency within a Perceptual Control Theory account. Finally the strengths and limitations of a Perceptual Control Theory account in explaining the mechanism of psychological change are considered.

  18. Quick linguistic representations and precise perceptual representations : Language statistics and perceptual simulations under time constraints

    NARCIS (Netherlands)

    Hutchinson, S; Tillman, R.N.; Louwerse, M.M.

    2014-01-01

    Many studies have argued that language comprehension requires perceptual simulation. In previous work we have demonstrated that because language encodes perceptual relations, comprehenders can also rely on language statistics to bootstrap meaning through limited grounding. The extent comprehenders

  19. Quick linguistic representations and precise perceptual representations : Language statistics and perceptual simulations under time constraints

    NARCIS (Netherlands)

    Hutchinson, S; Tillman, R.N.; Louwerse, M.M.

    2014-01-01

    Many studies have argued that language comprehension requires perceptual simulation. In previous work we have demonstrated that because language encodes perceptual relations, comprehenders can also rely on language statistics to bootstrap meaning through limited grounding. The extent comprehenders d

  20. Optimizing Linked Perceptual Class Formation and Transfer of Function

    Science.gov (United States)

    Fields, Lanny; Garruto, Michelle

    2009-01-01

    A linked perceptual class consists of two distinct perceptual classes, A' and B', the members of which have become related to each other. For example, a linked perceptual class might be composed of many pictures of a woman (one perceptual class) and the sounds of that woman's voice (the other perceptual class). In this case, any sound of the…

  1. Perceptual demand modulates activation of human auditory cortex in response to task-irrelevant sounds.

    Science.gov (United States)

    Sabri, Merav; Humphries, Colin; Verber, Matthew; Mangalathu, Jain; Desai, Anjali; Binder, Jeffrey R; Liebenthal, Einat

    2013-09-01

    In the visual modality, perceptual demand on a goal-directed task has been shown to modulate the extent to which irrelevant information can be disregarded at a sensory-perceptual stage of processing. In the auditory modality, the effect of perceptual demand on neural representations of task-irrelevant sounds is unclear. We compared simultaneous ERPs and fMRI responses associated with task-irrelevant sounds across parametrically modulated perceptual task demands in a dichotic-listening paradigm. Participants performed a signal detection task in one ear (Attend ear) while ignoring task-irrelevant syllable sounds in the other ear (Ignore ear). Results revealed modulation of syllable processing by auditory perceptual demand in an ROI in middle left superior temporal gyrus and in negative ERP activity 130-230 msec post stimulus onset. Increasing the perceptual demand in the Attend ear was associated with a reduced neural response in both fMRI and ERP to task-irrelevant sounds. These findings are in support of a selection model whereby ongoing perceptual demands modulate task-irrelevant sound processing in auditory cortex.

  2. Strategic Planning as a Perceptual Process,

    Science.gov (United States)

    1981-03-01

    Like any complex human endeavor, the sort of broad scope or long range organizational planning often referred to as strategic planning can be viewed...might be of use to planners and managers concerned with broad scope strategic planning .

  3. Perceptual effects of linguistic category priming : The Stapel and Semin paradigm revisited in twelve experiments

    NARCIS (Netherlands)

    IJzerman, H.; Regenberg, N.; Saddlemeyer, J.; Koole, S.L.

    2015-01-01

    Linguistic category priming is a novel paradigm to examine automatic influences of language on cognition (Semin, 2008). An initial article reported that priming abstract linguistic categories (adjectives) led to more global perceptual processing, whereas priming concrete linguistic categories

  4. Brain Network Connectivity During Language Comprehension: Interacting Linguistic and Perceptual Subsystems.

    Science.gov (United States)

    Fonteneau, Elisabeth; Bozic, Mirjana; Marslen-Wilson, William D

    2015-10-01

    The dynamic neural processes underlying spoken language comprehension require the real-time integration of general perceptual and specialized linguistic information. We recorded combined electro- and magnetoencephalographic measurements of participants listening to spoken words varying in perceptual and linguistic complexity. Combinatorial linguistic complexity processing was consistently localized to left perisylvian cortices, whereas competition-based perceptual complexity triggered distributed activity over both hemispheres. Functional connectivity showed that linguistically complex words engaged a distributed network of oscillations in the gamma band (20-60 Hz), which only partially overlapped with the network supporting perceptual analysis. Both processes enhanced cross-talk between left temporal regions and bilateral pars orbitalis (BA47). The left-lateralized synchrony between temporal regions and pars opercularis (BA44) was specific to the linguistically complex words, suggesting a specific role of left frontotemporal cross-cortical interactions in morphosyntactic computations. Synchronizations in oscillatory dynamics reveal the transient coupling of functional networks that support specific computational processes in language comprehension.

  5. Cerebellar tDCS dissociates the timing of perceptual decisions from perceptual change in speech

    NARCIS (Netherlands)

    Lametti, D.R.; Oostwoud Wijdenes, L.; Bonaiuto, J.; Bestmann, S.; Rothwell, J.C.

    2016-01-01

    Neuroimaging studies suggest that the cerebellum might play a role in both speech perception and speech perceptual learning. However, it remains unclear what this role is: does the cerebellum directly contribute to the perceptual decision? Or does it contribute to the timing of perceptual decisions?

  6. The Competitive Influences of Perceptual Load and Working Memory Guidance on Selective Attention.

    Science.gov (United States)

    Tan, Jinfeng; Zhao, Yuanfang; Wang, Lijun; Tian, Xia; Cui, Yan; Yang, Qian; Pan, Weigang; Zhao, Xiaoyue; Chen, Antao

    2015-01-01

    The perceptual load theory in selective attention literature proposes that the interference from task-irrelevant distractor is eliminated when perceptual capacity is fully consumed by task-relevant information. However, the biased competition model suggests that the contents of working memory (WM) can guide attentional selection automatically, even when this guidance is detrimental to visual search. An intriguing but unsolved question is what will happen when selective attention is influenced by both perceptual load and WM guidance. To study this issue, behavioral performances and event-related potentials (ERPs) were recorded when participants were presented with a cue to either identify or hold in memory and had to perform a visual search task subsequently, under conditions of low or high perceptual load. Behavioural data showed that high perceptual load eliminated the attentional capture by WM. The ERP results revealed an obvious WM guidance effect in P1 component with invalid trials eliciting larger P1 than neutral trials, regardless of the level of perceptual load. The interaction between perceptual load and WM guidance was significant for the posterior N1 component. The memory guidance effect on N1 was eliminated by high perceptual load. Standardized Low Resolution Electrical Tomography Analysis (sLORETA) showed that the WM guidance effect and the perceptual load effect on attention can be localized into the occipital area and parietal lobe, respectively. Merely identifying the cue produced no effect on the P1 or N1 component. These results suggest that in selective attention, the information held in WM could capture attention at the early stage of visual processing in the occipital cortex. Interestingly, this initial capture of attention by WM could be modulated by the level of perceptual load and the parietal lobe mediates target selection at the discrimination stage.

  7. Perceptual hashing algorithms benchmark suite

    Institute of Scientific and Technical Information of China (English)

    Zhang Hui; Schmucker Martin; Niu Xiamu

    2007-01-01

    Numerous perceptual hashing algorithms have been developed for identification and verification of multimedia objects in recent years. Many application schemes have been adopted for various commercial objects. Developers and users are looking for a benchmark tool to compare and evaluate their current algorithms or technologies. In this paper, a novel benchmark platform is presented. PHABS provides an open framework and lets its users define their own test strategy, perform tests, collect and analyze test data. With PHABS, various performance parameters of algorithms can be tested, and different algorithms or algorithms with different parameters can be evaluated and compared easily.

  8. Perceptual basis of evolving Western musical styles.

    Science.gov (United States)

    Rodriguez Zivic, Pablo H; Shifres, Favio; Cecchi, Guillermo A

    2013-06-11

    The brain processes temporal statistics to predict future events and to categorize perceptual objects. These statistics, called expectancies, are found in music perception, and they span a variety of different features and time scales. Specifically, there is evidence that music perception involves strong expectancies regarding the distribution of a melodic interval, namely, the distance between two consecutive notes within the context of another. The recent availability of a large Western music dataset, consisting of the historical record condensed as melodic interval counts, has opened new possibilities for data-driven analysis of musical perception. In this context, we present an analytical approach that, based on cognitive theories of music expectation and machine learning techniques, recovers a set of factors that accurately identifies historical trends and stylistic transitions between the Baroque, Classical, Romantic, and Post-Romantic periods. We also offer a plausible musicological and cognitive interpretation of these factors, allowing us to propose them as data-driven principles of melodic expectation.

  9. Mutual information, perceptual independence, and holistic face perception.

    Science.gov (United States)

    Fitousi, Daniel

    2013-07-01

    The concept of perceptual independence is ubiquitous in psychology. It addresses the question of whether two (or more) dimensions are perceived independently. Several authors have proposed perceptual independence (or its lack thereof) as a viable measure of holistic face perception (Loftus, Oberg, & Dillon, Psychological Review 111:835-863, 2004; Wenger & Ingvalson, Learning, Memory, and Cognition 28:872-892, 2002). According to this notion, the processing of facial features occurs in an interactive manner. Here, I examine this idea from the perspective of two theories of perceptual independence: the multivariate uncertainty analysis (MUA; Garner & Morton, Definitions, models, and experimental paradigms. Psychological Bulletin 72:233-259, 1969), and the general recognition theory (GRT; Ashby & Townsend, Psychological Review 93:154-179, 1986). The goals of the study were to (1) introduce the MUA, (2) examine various possible relations between MUA and GRT using numerical simulations, and (3) apply the MUA to two consensual markers of holistic face perception(-)recognition of facial features (Farah, Wilson, Drain, & Tanaka, Psychological Review 105:482-498, 1998) and the composite face effect (Young, Hellawell, & Hay, Perception 16:747-759, 1987). The results suggest that facial holism is generated by violations of several types of perceptual independence. They highlight the important theoretical role played by converging operations in the study of holistic face perception.

  10. Dichotomy and perceptual distortions in absolute pitch ability.

    Science.gov (United States)

    Athos, E Alexandra; Levinson, Barbara; Kistler, Amy; Zemansky, Jason; Bostrom, Alan; Freimer, Nelson; Gitschier, Jane

    2007-09-11

    Absolute pitch (AP) is the rare ability to identify the pitch of a tone without the aid of a reference tone. Understanding both the nature and genesis of AP can provide insights into neuroplasticity in the auditory system. We explored factors that may influence the accuracy of pitch perception in AP subjects both during the development of the trait and in later age. We used a Web-based survey and a pitch-labeling test to collect perceptual data from 2,213 individuals, 981 (44%) of whom proved to have extraordinary pitch-naming ability. The bimodal distribution in pitch-naming ability signifies AP as a distinct perceptual trait, with possible implications for its genetic basis. The wealth of these data has allowed us to uncover unsuspected note-naming irregularities suggestive of a "perceptual magnet" centered at the note "A." In addition, we document a gradual decline in pitch-naming accuracy with age, characterized by a perceptual shift in the "sharp" direction. These findings speak both to the process of acquisition of AP and to its stability.

  11. Multisensory perceptual learning is dependent upon task difficulty.

    Science.gov (United States)

    De Niear, Matthew A; Koo, Bonhwang; Wallace, Mark T

    2016-11-01

    There has been a growing interest in developing behavioral tasks to enhance temporal acuity as recent findings have demonstrated changes in temporal processing in a number of clinical conditions. Prior research has demonstrated that perceptual training can enhance temporal acuity both within and across different sensory modalities. Although certain forms of unisensory perceptual learning have been shown to be dependent upon task difficulty, this relationship has not been explored for multisensory learning. The present study sought to determine the effects of task difficulty on multisensory perceptual learning. Prior to and following a single training session, participants completed a simultaneity judgment (SJ) task, which required them to judge whether a visual stimulus (flash) and auditory stimulus (beep) presented in synchrony or at various stimulus onset asynchronies (SOAs) occurred synchronously or asynchronously. During the training session, participants completed the same SJ task but received feedback regarding the accuracy of their responses. Participants were randomly assigned to one of three levels of difficulty during training: easy, moderate, and hard, which were distinguished based on the SOAs used during training. We report that only the most difficult (i.e., hard) training protocol enhanced temporal acuity. We conclude that perceptual training protocols for enhancing multisensory temporal acuity may be optimized by employing audiovisual stimuli for which it is difficult to discriminate temporal synchrony from asynchrony.

  12. Perceptual learning of acoustic noise generates memory-evoked potentials.

    Science.gov (United States)

    Andrillon, Thomas; Kouider, Sid; Agus, Trevor; Pressnitzer, Daniel

    2015-11-01

    Experience continuously imprints on the brain at all stages of life. The traces it leaves behind can produce perceptual learning [1], which drives adaptive behavior to previously encountered stimuli. Recently, it has been shown that even random noise, a type of sound devoid of acoustic structure, can trigger fast and robust perceptual learning after repeated exposure [2]. Here, by combining psychophysics, electroencephalography (EEG), and modeling, we show that the perceptual learning of noise is associated with evoked potentials, without any salient physical discontinuity or obvious acoustic landmark in the sound. Rather, the potentials appeared whenever a memory trace was observed behaviorally. Such memory-evoked potentials were characterized by early latencies and auditory topographies, consistent with a sensory origin. Furthermore, they were generated even on conditions of diverted attention. The EEG waveforms could be modeled as standard evoked responses to auditory events (N1-P2) [3], triggered by idiosyncratic perceptual features acquired through learning. Thus, we argue that the learning of noise is accompanied by the rapid formation of sharp neural selectivity to arbitrary and complex acoustic patterns, within sensory regions. Such a mechanism bridges the gap between the short-term and longer-term plasticity observed in the learning of noise [2, 4-6]. It could also be key to the processing of natural sounds within auditory cortices [7], suggesting that the neural code for sound source identification will be shaped by experience as well as by acoustics.

  13. Perceptual Orientation for Housing Interior Walls Finishes Choice and Preference

    Directory of Open Access Journals (Sweden)

    Dr. ZINAS, Bako Zachariah

    2015-02-01

    Full Text Available Housing interior walls are decorated and finished with various decorative materials of paints of varying properties ranging from texture to coloration. In choosing the preferred finishing and decorative materials, housing owners, users and prospective owners have attendant underlying factors and reasons for their choices. These choice activities usually provoke and invoke certain perceptual orientations that underlie the choices. These perceptual orientations are normally very complex and can only be disentangled by elicitation. This paper presents perceptual orientations of prospective house owners‟ choice and preference for interior walls finishes in Yola, Nigeria. The study was conducted within the theoretical and conceptual framework of means-end chain (MEC model. 15 prospective house owners were interviewed using the laddering interviewing technique after a structured questionnaire survey was carried out. The results showed that twelve (12 identified unique perceptual orientation pathways were established, motivated by four (4 user values, and intervened by four (4 expected functional affordances. The findings disentangled the design expectations of housing users/owners for finishing their housing interiors which can be pointers for designers and Architects for their design processes and decisions.

  14. The Multisensory Temporal Binding Window: Perceptual Fusion, Training, and Autism

    Directory of Open Access Journals (Sweden)

    Ryan A Stevenson

    2011-10-01

    Full Text Available The process of integrating information across sensory modalities is highly dependent upon the temporal coincidence of the inputs. Audiovisual information is integrated within a range of temporal offsets, known as the temporal binding window (TBW, which varies between individuals. Three particular findings relating to TBW have led us to a novel approach to address sensory integration impairments in children with autism. The first is that autistic children have an atypically wide TBW, as measured through manipulations of audiovisual illusions. Second, an individual's TBW is related to their ability to perceptually fuse audiovisual inputs, particularly as seen in the McGurk effect; the narrower the right TBW, the stronger the McGurk effect. The third finding is that the TBW is plastic. Through perceptual feedback training, our lab showed that individuals' right TBW can be narrowed. These three findings, which we will present, lead to a study of perceptual feedback training in autistic children, who may have the ability to narrow their TBW, with a possible positive impact on their ability to integrate multisensory information, specifically speech. We will conclude with the presentation of behavioral and electrophysiological data illustrating an atypical relationship between the TBW and perceptual fusion in ASD.

  15. Mental imagery of speech: linking motor and perceptual systems through internal simulation and estimation

    Directory of Open Access Journals (Sweden)

    Xing eTian

    2012-11-01

    Full Text Available The neural basis of mental imagery has been investigated by localizing the underlying neural networks, mostly in motor and perceptual systems, separately. However, how modality-specific representations are top-down induced and how the action and perception systems interact in the context of mental imagery is not well understood. Imagined speech production (‘articulation imagery’, which induces the kinesthetic feeling of articulator movement and its auditory consequences, provides a new angle because of the concurrent involvement of motor and perceptual systems. On the basis of previous findings in mental imagery of speech, we argue for the following regarding the induction mechanisms of mental imagery and the interaction between motor and perceptual systems: (1 Two distinct top-down mechanisms, memory retrieval and motor simulation, exist to induce estimation in perceptual systems. (2 Motor simulation is sufficient to internally induce the representation of perceptual changes that would be caused by actual movement (perceptual associations; however, this simulation process only has modulatory effects on the perception of external stimuli, which critically depends on context and task demands. Considering the proposed simulation-estimation processes as common mechanisms for interaction between motor and perceptual systems, we outline how mental imagery (of speech relates to perception and production, and how these hypothesized mechanisms might underpin certain neural disorders.

  16. Applying Transcranial Magnetic Stimulation (TMS) Over the Dorsal Visual Pathway Induces Schizophrenia-like Disruption of Perceptual Closure.

    Science.gov (United States)

    Amiaz, Revital; Vainiger, Dana; Gershon, Ari A; Weiser, Mark; Lavidor, Michal; Javitt, Daniel C

    2016-07-01

    Perceptual closure ability is postulated to depend upon rapid transmission of magnocellular information to prefrontal cortex via the dorsal stream. In contrast, illusory contour processing requires only local interactions within primary and ventral stream visual regions, such as lateral occipital complex. Schizophrenia is associated with deficits in perceptual closure versus illusory contours processing that is hypothesized to reflect impaired magnocellular/dorsal stream. Perceptual closure and illusory contours performance was evaluated in separate groups of 12 healthy volunteers during no TMS, and during repetitive 10 Hz rTMS stimulation over dorsal stream or vertex (TMS-vertex). Perceptual closure and illusory contours were performed in 11 schizophrenia patients, no TMS was applied in these patients. TMS effects were evaluated with repeated measures ANOVA across treatments. rTMS significantly increased perceptual closure identification thresholds, with significant difference between TMS-dorsal stream and no TMS. TMS-dorsal stream also significantly reduced perceptual closure but not illusory contours accuracy. Schizophrenia patients showed increased perceptual closure identification thresholds relative to controls in the no TMS condition, but similar to controls in the TMS-dorsal stream condition. Conclusions of this study are that magnocellular/dorsal stream input is critical for perceptual closure but not illusory contours performance, supporting both trickledown theories of normal perceptual closure function, and magnocellular/dorsal stream theories of visual dysfunction in schizophrenia.

  17. NEW VISUAL PERCEPTUAL POOLING STRATEGY FOR IMAGE QUALITY ASSESSMENT

    Institute of Scientific and Technical Information of China (English)

    Zhou Wujie; Jiang Gangyi; Yu Mei

    2012-01-01

    Most of Image Quality Assessment (IQA) metrics consist of two processes.In the first process,quality map of image is measured locally.In the second process,the last quality score is converted from the quality map by using the pooling strategy.The first process had been made effective and significant progresses,while the second process was always done in simple ways.In the second process of the pooling strategy,the optimal perceptual pooling weights should be determined and computed according to Human Visual System (HVS).Thus,a reliable spatial pooling mathematical model based on HVS is an important issue worthy of study.In this paper,a new Visual Perceptual Pooling Strategy (VPPS) for IQA is presented based on contrast sensitivity and luminance sensitivity of HVS.Experimental results with the LIVE database show that the visual perceptual weights,obtained by the proposed pooling strategy,can effectively and significantly improve the performances of the IQA metrics with Mean Structural SIMilarity (MSSIM) or Phase Quantization Code (PQC).It is confirmed that the proposed VPPS demonstrates promising results for improving the performances of existing IQA metrics.

  18. Perceptual effects of linguistic category priming: the Stapel and Semin (2007) paradigm revisited in twelve experiments.

    Science.gov (United States)

    IJzerman, Hans; Regenberg, Nina F E; Saddlemyer, Justin; Koole, Sander L

    2015-05-01

    Linguistic category priming is a novel paradigm to examine automatic influences of language on cognition (Semin, 2008). An initial article reported that priming abstract linguistic categories (adjectives) led to more global perceptual processing, whereas priming concrete linguistic categories (verbs) led to more local perceptual processing (Stapel & Semin, 2007). However, this report was compromised by data fabrication by the first author, so that it remains unclear whether or not linguistic category priming influences perceptual processing. To fill this gap in the literature, the present article reports 12 studies among Dutch and US samples examining the perceptual effects of linguistic category priming. The results yielded no evidence of linguistic category priming effects. These findings are discussed in relation to other research showing cultural variations in linguistic category priming effects (IJzerman, Saddlemyer, & Koole, 2014). The authors conclude by highlighting the importance of conducting and publishing replication research for achieving scientific progress. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  19. Lightening the load: perceptual load impairs visual detection in typical adults but not in autism.

    Science.gov (United States)

    Remington, Anna M; Swettenham, John G; Lavie, Nilli

    2012-05-01

    Autism spectrum disorder (ASD) research portrays a mixed picture of attentional abilities with demonstrations of enhancements (e.g., superior visual search) and deficits (e.g., higher distractibility). Here we test a potential resolution derived from the Load Theory of Attention (e.g., Lavie, 2005). In Load Theory, distractor processing depends on the perceptual load of the task and as such can only be eliminated under high load that engages full capacity. We hypothesize that ASD involves enhanced perceptual capacity, leading to the superior performance and increased distractor processing previously reported. Using a signal-detection paradigm, we test this directly and demonstrate that, under higher levels of load, perceptual sensitivity was reduced in typical adults but not in adults with ASD. These findings confirm our hypothesis and offer a promising solution to the previous discrepancies by suggesting that increased distractor processing in ASD results not from a filtering deficit but from enhanced perceptual capacity.

  20. Task-irrelevant perceptual expertise.

    Science.gov (United States)

    Wong, Yetta K; Folstein, Jonathan R; Gauthier, Isabel

    2011-12-05

    Perceptual learning (PL) and perceptual expertise (PE) are two fields of visual training studies that investigate how practice improves visual performance. However, previous research suggests that PL can be acquired in a task-irrelevant manner while PE cannot and that PL is highly specific to the training objects and conditions while PE generalizes. These differences are difficult to interpret since PL and PE studies tend to differ on multiple dimensions. We designed a training study with novel objects to compare PL and PE while varying only the training task, such that the training objects, visual field, training duration, and type of learning assessment were kept constant. Manipulations of the training task sufficed to produce the standard effects obtained in PE and PL. In contrast to prior studies, we demonstrated that some degree of PE can be acquired in a task-irrelevant manner, similar to PL. Task-irrelevant PE resulted in similar shape matching ability compared to the directly trained PE. In addition, learning in both PE and PL generalizes to different untrained conditions, which does not support the idea that PE generalizes while PL is specific. Degrees of generalization can be explained by considering the psychological space of the stimuli used for training and the test of transfer.

  1. The perceptual balance of color

    Science.gov (United States)

    McDermott, Kyle C.; Webster, Michael A.

    2011-01-01

    The cone contrasts carrying different dimensions of color vision vary greatly in magnitude, yet the perceived contrast of color and luminance in the world appears similar. We examined how this perceptual balance is adjusted by adaptation to the contrast in images. Observers set the level of L vs. M and S vs. LM contrast in 1/f noise images to match the perceived strength of a fixed level of luminance contrast. The perceptual balance of color in the images was roughly consistent with the range of contrasts characteristic of natural images. Relative perceived contrast could be strongly biased by brief prior exposure to images with lower or higher levels of chromatic contrast. Similar adaptation effects were found for luminance contrast in images of natural scenes. For both, observers reliably chose the contrast balance that appeared correct, and these choices were rapidly recalibrated by adaptation. This recalibration of the norm for contrast could reflect both changes in sensitivity and shifts in criterion. Our results are consistent with the possibility that color mechanisms adjust the range of their responses to match the range of signals in the environment, and that contrast adaptation plays an important role in these adjustments. PMID:22330367

  2. Building online brand perceptual map.

    Science.gov (United States)

    Chiang, I-Ping; Lin, Chih-Ying; Wang, Kaisheng M

    2008-10-01

    Many companies have launched their products or services online as a new business focus, but only a few of them have survived the competition and made profits. The most important key to an online business's success is to create "brand value" for the customers. Although the concept of online brand has been discussed in previous studies, there is no empirical study on the measurement of online branding. As Web 2.0 emerges to be critical to online branding, the purpose of this study was to measure Taiwan's major Web sites with a number of personality traits to build a perceptual map for online brands. A pretest identified 10 most representative online brand perceptions. The results of the correspondence analysis showed five groups in the perceptual map. This study provided a practical view of the associations and similarities among online brands for potential alliance or branding strategies. The findings also suggested that brand perceptions can be used with identified consumer needs and behaviors to better position online services. The brand perception map in the study also contributed to a better understanding of the online brands in Taiwan.

  3. Semantic Representations in 3D Perceptual Space

    Directory of Open Access Journals (Sweden)

    Suncica Zdravkovic

    2011-05-01

    Full Text Available Barsalou's (1999 perceptual theory of knowledge echoes the pre-20th century tradition of conceptualizing all knowledge as inherently perceptual. Hence conceptual space has an infinite number of dimensions and heavily relies on perceptual experience. Osgood's (1952 semantic differential technique was developed as a bridge between perception and semantics. We updated Osgood's methodology in order to investigate current issues in visual cognition by: (1 using a 2D rather than a 1D space to place the concepts, (2 having dimensions that were perceptual while the targets were conceptual, (3 coupling visual experience with another two perceptual domains (audition and touch, (4 analyzing the data using MDS (not factor analysis. In three experiments, subjects (N = 57 judged five concrete and five abstract words on seven bipolar scales in three perceptual modalities. The 2D space led to different patterns of response compared to the classic 1D space. MDS revealed that perceptual modalities are not equally informative for mapping word-meaning distances (Mantel min = −.23; Mantel max = .88. There was no reliable differences due to test administration modality (paper vs. computer, nor scale orientation. The present findings are consistent with multidimensionality of conceptual space, a perceptual basis for knowledge, and dynamic characteristics of concepts discussed in contemporary theories.

  4. 汉语第一、二语言学习者鼻音感知过程实验研究∗%An Experimental Study on the Perceptual Process of Mandarin Nasals by L1 and L2 Learners

    Institute of Scientific and Technical Information of China (English)

    吴菲

    2016-01-01

    汉语鼻音输出的声学线索表明,音节末尾的鼻音差别经常难以辨认。迄今为止,少有研究探讨汉语第一、二语言学习者的鼻音感知过程差异,即他们在辨认鼻音的过程中程度和方向上有何异同。同时还应考虑语言背景(第一还是第二语言学习者)、元音组合(如[i、ə、a、y、ua、uə、ia])、语音环境(如音节首还是音节尾)等因素对感知的影响。经过实验统计和分析,由印欧语发展而来的言语学习理论,例如言语学习模式和标志性差异假设在解释汉语鼻音感知方面存在一定局限性,需要建立一个新的三维交互模型以解释其认知机制。%The acoustic analysis of Mandarin nasal production indicates that syllable-final distinc-tion is frequently dropped.Till now,few studies have addressed the issue of perceptual process of Mandarin nasals and to what extent and in what direction L1 and L2 speakers differ in perceiving Man-darin nasals.What needs to be taken into consideration include language proficiency (L1 vs.L2 speakers),vocalic contexts (i.e.[i,ə,a,y,ua,uə,ia]),and phonetic settings (at the initial or end of syllables).Data analysis of previous speech learning models such as the Speech Learning Model and the Markedness Differential Hypothesis developed from the studies of Indo-European languages shows limitations in the context of Mandarin nasals.The paper proposes a new “Tri-dimensional Interactive Model”to illustrate the cognitive mechanism of Mandarin nasal perception.

  5. Asymmetric transfer of auditory perceptual learning

    Directory of Open Access Journals (Sweden)

    Sygal eAmitay

    2012-11-01

    Full Text Available Perceptual skills can improve dramatically even with minimal practice. A major and practical benefit of learning, however, is in transferring the improvement on the trained task to untrained tasks or stimuli, yet the mechanisms underlying this process are still poorly understood. Reduction of internal noise has been proposed as a mechanism of perceptual learning, and while we have evidence that frequency discrimination (FD learning is due to a reduction of internal noise, the source of that noise was not determined. In this study, we examined whether reducing the noise associated with neural phase locking to tones can explain the observed improvement in behavioural thresholds. We compared FD training between two tone durations (15 and 100 ms that straddled the temporal integration window of auditory nerve fibers upon which computational modeling of phase locking noise was based. Training on short tones resulted in improved FD on probe tests of both the long and short tones. Training on long tones resulted in improvement only on the long tones. Simulations of FD learning, based on the computational model and on signal detection theory, were compared with the behavioral FD data. We found that improved fidelity of phase locking accurately predicted transfer of learning from short to long tones, but also predicted transfer from long to short tones. The observed lack of transfer from long to short tones suggests the involvement of a second mechanism. Training may have increased the temporal integration window which could not transfer because integration time for the short tone is limited by its duration. Current learning models assume complex relationships between neural populations that represent the trained stimuli. In contrast, we propose that training-induced enhancement of the signal-to-noise ratio offers a parsimonious explanation of learning and transfer that easily accounts for asymmetric transfer of learning.

  6. Distributed Processing and Cortical Specialization for Speech and Environmental Sounds in Human Temporal Cortex

    Science.gov (United States)

    Leech, Robert; Saygin, Ayse Pinar

    2011-01-01

    Using functional MRI, we investigated whether auditory processing of both speech and meaningful non-linguistic environmental sounds in superior and middle temporal cortex relies on a complex and spatially distributed neural system. We found that evidence for spatially distributed processing of speech and environmental sounds in a substantial…

  7. Working memory load influences perceptual ambiguity by competing for fronto-parietal attentional resources.

    Science.gov (United States)

    Intaitė, Monika; Duarte, João Valente; Castelo-Branco, Miguel

    2016-11-01

    A visual stimulus is defined as ambiguous when observers perceive it as having at least two distinct and spontaneously alternating interpretations. Neuroimaging studies suggest an involvement of a right fronto-parietal network regulating the balance between stable percepts and the triggering of alternative interpretations. As spontaneous perceptual reversals may occur even in the absence of attention to these stimuli, we investigated neural activity patterns in response to perceptual changes of ambiguous Necker cube under different amounts of working memory load using a dual-task design. We hypothesized that the same regions that process working memory load are involved in perceptual switching and confirmed the prediction that perceptual reversals led to fMRI responses that linearly depended on load. Accordingly, posterior Superior Parietal Lobule, anterior Prefrontal and Dorsolateral Prefrontal cortices exhibited differential BOLD signal changes in response to perceptual reversals under working memory load. Our results also suggest that the posterior Superior Parietal Lobule may be directly involved in the emergence of perceptual reversals, given that it specifically reflects both perceptual versus real changes and load levels. The anterior Prefrontal and Dorsolateral Prefrontal cortices, showing a significant interaction between reversal levels and load, might subserve a modulatory role in such reversals, in a mirror symmetric way: in the former activation is suppressed by the highest loads, and in the latter deactivation is reduced by highest loads, suggesting a more direct role of the aPFC in reversal generation.

  8. "The Mask Who Wasn't There": Visual Masking Effect with the Perceptual Absence of the Mask

    Science.gov (United States)

    Rey, Amandine Eve; Riou, Benoit; Muller, Dominique; Dabic, Stéphanie; Versace, Rémy

    2015-01-01

    Does a visual mask need to be perceptually present to disrupt processing? In the present research, we proposed to explore the link between perceptual and memory mechanisms by demonstrating that a typical sensory phenomenon (visual masking) can be replicated at a memory level. Experiment 1 highlighted an interference effect of a visual mask on the…

  9. Disambiguating Multi–Modal Scene Representations Using Perceptual Grouping Constraints

    Science.gov (United States)

    Pugeault, Nicolas; Wörgötter, Florentin; Krüger, Norbert

    2010-01-01

    In its early stages, the visual system suffers from a lot of ambiguity and noise that severely limits the performance of early vision algorithms. This article presents feedback mechanisms between early visual processes, such as perceptual grouping, stereopsis and depth reconstruction, that allow the system to reduce this ambiguity and improve early representation of visual information. In the first part, the article proposes a local perceptual grouping algorithm that — in addition to commonly used geometric information — makes use of a novel multi–modal measure between local edge/line features. The grouping information is then used to: 1) disambiguate stereopsis by enforcing that stereo matches preserve groups; and 2) correct the reconstruction error due to the image pixel sampling using a linear interpolation over the groups. The integration of mutual feedback between early vision processes is shown to reduce considerably ambiguity and noise without the need for global constraints. PMID:20544006

  10. Perceptual fluency and judgments of vocal aesthetics and stereotypicality.

    Science.gov (United States)

    Babel, Molly; McGuire, Grant

    2015-05-01

    Research has shown that processing dynamics on the perceiver's end determine aesthetic pleasure. Specifically, typical objects, which are processed more fluently, are perceived as more attractive. We extend this notion of perceptual fluency to judgments of vocal aesthetics. Vocal attractiveness has traditionally been examined with respect to sexual dimorphism and the apparent size of a talker, as reconstructed from the acoustic signal, despite evidence that gender-specific speech patterns are learned social behaviors. In this study, we report on a series of three experiments using 60 voices (30 females) to compare the relationship between judgments of vocal attractiveness, stereotypicality, and gender categorization fluency. Our results indicate that attractiveness and stereotypicality are highly correlated for female and male voices. Stereotypicality and categorization fluency were also correlated for male voices, but not female voices. Crucially, stereotypicality and categorization fluency interacted to predict attractiveness, suggesting the role of perceptual fluency is present, but nuanced, in judgments of human voices.

  11. Perceptual context and individual differences in the language proficiency of preschool children.

    Science.gov (United States)

    Banai, Karen; Yifat, Rachel

    2016-02-01

    Although the contribution of perceptual processes to language skills during infancy is well recognized, the role of perception in linguistic processing beyond infancy is not well understood. In the experiments reported here, we asked whether manipulating the perceptual context in which stimuli are presented across trials influences how preschool children perform visual (shape-size identification; Experiment 1) and auditory (syllable identification; Experiment 2) tasks. Another goal was to determine whether the sensitivity to perceptual context can explain part of the variance in oral language skills in typically developing preschool children. Perceptual context was manipulated by changing the relative frequency with which target visual (Experiment 1) and auditory (Experiment 2) stimuli were presented in arrays of fixed size, and identification of the target stimuli was tested. Oral language skills were assessed using vocabulary, word definition, and phonological awareness tasks. Changes in perceptual context influenced the performance of the majority of children on both identification tasks. Sensitivity to perceptual context accounted for 7% to 15% of the variance in language scores. We suggest that context effects are an outcome of a statistical learning process. Therefore, the current findings demonstrate that statistical learning can facilitate both visual and auditory identification processes in preschool children. Furthermore, consistent with previous findings in infants and in older children and adults, individual differences in statistical learning were found to be associated with individual differences in language skills of preschool children.

  12. Interdisciplinary Adventures in Perceptual Ecology

    Science.gov (United States)

    Bocast, Christopher S.

    A portfolio dissertation that began as acoustic ecology and matured into perceptual ecology, centered on ecomusicology, bioacoustics, and translational audio-based media works with environmental perspectives. The place of music in Western eco-cosmology through time provides a basis for structuring an environmental history of human sound perception. That history suggests that music may stabilize human mental activity, and that an increased musical practice may be essential for the human project. An overview of recent antecedents preceding the emergence of acoustic ecology reveals structural foundations from 20th century culture that underpin modern sound studies. The contextual role that Aldo Leopold, Jacob von Uexkull, John Cage, Marshall McLuhan, and others played in anticipating the development of acoustic ecology as an interdiscipline is detailed. This interdisciplinary aspect of acoustic ecology is defined and defended, while new developments like soundscape ecology are addressed, though ultimately sound studies will need to embrace a broader concept of full-spectrum "sensory" or "perceptual" ecology. The bioacoustic fieldwork done on spawning sturgeon emphasized this necessity. That study yielded scientific recordings and spectrographic analyses of spawning sounds produced by lake sturgeon, Acipenser fulvescens, during reproduction in natural habitats in the Lake Winnebago watershed in Wisconsin. Recordings were made on the Wolf and Embarrass River during the 2011-2013 spawning seasons. Several specimens were dissected to investigate possible sound production mechanisms; no sonic musculature was found. Drumming sounds, ranging from 5 to 7 Hz fundamental frequency, verified the infrasonic nature of previously undocumented "sturgeon thunder". Other characteristic noises of sturgeon spawning including low-frequency rumbles and hydrodynamic sounds were identified. Intriguingly, high-frequency signals resembling electric organ discharges were discovered. These

  13. Perceptual and conceptual content of human consciousness--a perspective of the philosophy of mind.

    Science.gov (United States)

    Janović, T; Pećnjak, D

    2001-12-01

    The relation of the perceptual and the conceptual aspect of human mental states and process is discussed in light of some recent discussions. Several philosophical arguments for and against the conclusion that perceptual content is a non-conceptual type of representation are presented and critically assessed. The possibility of an objective criterion for resolving the issue, independent of introspective reports and intuitive conjectures, is considered.

  14. Gestalt perceptual organization of visual stimuli captures attention automatically: Electrophysiological evidence

    OpenAIRE

    Francesco Marini; Carlo Alberto Marzi

    2016-01-01

    The visual system leverages organizational regularities of perceptual elements to create meaningful representations of the world. One clear example of such function, which has been formalized in the Gestalt psychology principles, is the perceptual grouping of simple visual elements (e.g., lines and arcs) into unitary objects (e.g., forms and shapes). The present study sought to characterize automatic attentional capture and related cognitive processing of Gestalt-like visual stimuli at the ps...

  15. Gestalt Perceptual Organization of Visual Stimuli Captures Attention Automatically: Electrophysiological Evidence

    OpenAIRE

    Marini, Francesco; Marzi, Carlo A.

    2016-01-01

    The visual system leverages organizational regularities of perceptual elements to create meaningful representations of the world. One clear example of such function, which has been formalized in the Gestalt psychology principles, is the perceptual grouping of simple visual elements (e.g., lines and arcs) into unitary objects (e.g., forms and shapes). The present study sought to characterize automatic attentional capture and related cognitive processing of Gestalt-like visual stimuli at the ps...

  16. Enhancement and suppression in the visual field under perceptual load.

    Science.gov (United States)

    Parks, Nathan A; Beck, Diane M; Kramer, Arthur F

    2013-01-01

    The perceptual load theory of attention proposes that the degree to which visual distractors are processed is a function of the attentional demands of a task-greater demands increase filtering of irrelevant distractors. The spatial configuration of such filtering is unknown. Here, we used steady-state visual evoked potentials (SSVEPs) in conjunction with time-domain event-related potentials (ERPs) to investigate the distribution of load-induced distractor suppression and task-relevant enhancement in the visual field. Electroencephalogram (EEG) was recorded while subjects performed a foveal go/no-go task that varied in perceptual load. Load-dependent distractor suppression was assessed by presenting a contrast reversing ring at one of three eccentricities (2, 6, or 11°) during performance of the go/no-go task. Rings contrast reversed at 8.3 Hz, allowing load-dependent changes in distractor processing to be tracked in the frequency-domain. ERPs were calculated to the onset of stimuli in the load task to examine load-dependent modulation of task-relevant processing. Results showed that the amplitude of the distractor SSVEP (8.3 Hz) was attenuated under high perceptual load (relative to low load) at the most proximal (2°) eccentricity but not at more eccentric locations (6 or 11°). Task-relevant ERPs revealed a significant increase in N1 amplitude under high load. These results are consistent with a center-surround configuration of load-induced enhancement and suppression in the visual field.

  17. Perceptual rivalry: reflexes reveal the gradual nature of visual awareness.

    Directory of Open Access Journals (Sweden)

    Marnix Naber

    Full Text Available Rivalry is a common tool to probe visual awareness: a constant physical stimulus evokes multiple, distinct perceptual interpretations ("percepts" that alternate over time. Percepts are typically described as mutually exclusive, suggesting that a discrete (all-or-none process underlies changes in visual awareness. Here we follow two strategies to address whether rivalry is an all-or-none process: first, we introduce two reflexes as objective measures of rivalry, pupil dilation and optokinetic nystagmus (OKN; second, we use a continuous input device (analog joystick to allow observers a gradual subjective report. We find that the "reflexes" reflect the percept rather than the physical stimulus. Both reflexes show a gradual dependence on the time relative to perceptual transitions. Similarly, observers' joystick deflections, which are highly correlated with the reflex measures, indicate gradual transitions. Physically simulating wave-like transitions between percepts suggest piece-meal rivalry (i.e., different regions of space belonging to distinct percepts as one possible explanation for the gradual transitions. Furthermore, the reflexes show that dominance durations depend on whether or not the percept is actively reported. In addition, reflexes respond to transitions with shorter latencies than the subjective report and show an abundance of short dominance durations. This failure to report fast changes in dominance may result from limited access of introspection to rivalry dynamics. In sum, reflexes reveal that rivalry is a gradual process, rivalry's dynamics is modulated by the required action (response mode, and that rapid transitions in perceptual dominance can slip away from awareness.

  18. Perceptual learning is specific beyond vision and decision making.

    Science.gov (United States)

    Grzeczkowski, Lukasz; Cretenoud, Aline; Herzog, Michael H; Mast, Fred W

    2017-06-01

    Perceptual learning is usually assumed to occur within sensory areas or when sensory evidence is mapped onto decisions. Subsequent procedural and motor processes, involved in most perceptual learning experiments, are thought to play no role in the learning process. Here, we show that this is not the case. Observers trained with a standard three-line bisection task and indicated the offset direction of the central line by pressing either a left or right push button. Before and after training, observers adjusted the central line of the same bisection stimulus using a computer mouse. As expected, performance improved through training. Surprisingly, learning did not transfer to the untrained mouse adjustment condition. The same was true for the opposite, i.e., training with mouse adjustments did not transfer to the push button condition. We found partial transfer when observers adjusted the central line with two different adjustment procedures. We suggest that perceptual learning is specific to procedural motor aspects beyond visual processing. Our results support theories were visual stimuli are coded together with their corresponding actions.

  19. Looking without Perceiving: Impaired Preattentive Perceptual Grouping in Autism Spectrum Disorder.

    Directory of Open Access Journals (Sweden)

    Tiffany A Carther-Krone

    Full Text Available Before becoming aware of a visual scene, our perceptual system has organized and selected elements in our environment to which attention should be allocated. Part of this process involves grouping perceptual features into a global whole. Individuals with autism spectrum disorders (ASD rely on a more local processing strategy, which may be driven by difficulties perceptually grouping stimuli. We tested this notion using a line discrimination task in which two horizontal lines were superimposed on a background of black and white dots organized so that, on occasion, the dots induced the Ponzo illusion if perceptually grouped together. Results showed that even though neither group was aware of the illusion, the ASD group was significantly less likely than typically developing group to make perceptual judgments influenced by the illusion, revealing difficulties in preattentive grouping of visual stimuli. This may explain why individuals with ASD rely on local processing strategies, and offers new insight into the mechanism driving perceptual grouping in the typically developing human brain.

  20. Healthy Older Observers Show Equivalent Perceptual-Cognitive Training Benefits to Young Adults for Multiple Object Tracking

    OpenAIRE

    Legault, Isabelle; Allard, Rémy; Faubert, Jocelyn

    2013-01-01

    The capacity to process complex dynamic scenes is of critical importance in real life. For instance, traveling through a crowd while avoiding collisions and maintaining orientation and good motor control requires fluent and continuous perceptual-cognitive processing. It is well documented that effects of healthy aging can influence perceptual-cognitive processes (Faubert, 2002) and that the efficiency of such processes can improve with training even for older adults (Richards et al., 2006). H...

  1. Individual differences at high perceptual load: the relation between trait anxiety and selective attention.

    Science.gov (United States)

    Sadeh, Naomi; Bredemeier, Keith

    2011-06-01

    Attentional control theory (Eysenck et al., 2007) posits that taxing attentional resources impairs performance efficiency in anxious individuals. This theory, however, does not explicitly address if or how the relation between anxiety and attentional control depends upon the perceptual demands of the task at hand. Consequently, the present study examined the relation between trait anxiety and task performance using a perceptual load task (Maylor & Lavie, 1998). Sixty-eight male college students completed a visual search task that indexed processing of irrelevant distractors systematically across four levels of perceptual load. Results indicated that anxiety was related to difficulty suppressing the behavioural effects of irrelevant distractors (i.e., decreased reaction time efficiency) under high, but not low, perceptual loads. In contrast, anxiety was not associated with error rates on the task. These findings are consistent with the prediction that anxiety is associated with impairments in performance efficiency under conditions that tax attentional resources.

  2. Perceptual-Cognitive Expertise in Elite Volleyball Players

    Science.gov (United States)

    Alves, Heloisa; Voss, Michelle W.; Boot, Walter R.; Deslandes, Andrea; Cossich, Victor; Salles, Jose Inacio; Kramer, Arthur F.

    2013-01-01

    The goal of the current study was to investigate the relationship between sport expertise and perceptual and cognitive skills, as measured by the component skills approach. We hypothesized that athletes would outperform non-athlete controls in a number of perceptual and cognitive domains and that sport expertise would minimize gender differences. A total of 154 individuals (87 professional volleyball players and 67 non-athlete controls) participated in the study. Participants performed a cognitive battery, which included tests of executive control, memory, and visuo-spatial attention. Athletes showed superior performance speed on three tasks (two executive control tasks and one visuo-spatial attentional processing task). In a subset of tasks, gender effects were observed mainly in the control group, supporting the notion that athletic experience can reduce traditional gender effects. The expertise effects obtained substantiate the view that laboratory tests of cognition may indeed enlighten the sport-cognition relationship. PMID:23471100

  3. Perceptual image hashing via feature points: performance evaluation and tradeoffs.

    Science.gov (United States)

    Monga, Vishal; Evans, Brian L

    2006-11-01

    We propose an image hashing paradigm using visually significant feature points. The feature points should be largely invariant under perceptually insignificant distortions. To satisfy this, we propose an iterative feature detector to extract significant geometry preserving feature points. We apply probabilistic quantization on the derived features to introduce randomness, which, in turn, reduces vulnerability to adversarial attacks. The proposed hash algorithm withstands standard benchmark (e.g., Stirmark) attacks, including compression, geometric distortions of scaling and small-angle rotation, and common signal-processing operations. Content changing (malicious) manipulations of image data are also accurately detected. Detailed statistical analysis in the form of receiver operating characteristic (ROC) curves is presented and reveals the success of the proposed scheme in achieving perceptual robustness while avoiding misclassification.

  4. Perceptual image hashing based on virtual watermark detection.

    Science.gov (United States)

    Khelifi, Fouad; Jiang, Jianmin

    2010-04-01

    This paper proposes a new robust and secure perceptual image hashing technique based on virtual watermark detection. The idea is justified by the fact that the watermark detector responds similarly to perceptually close images using a non embedded watermark. The hash values are extracted in binary form with a perfect control over the probability distribution of the hash bits. Moreover, a key is used to generate pseudo-random noise whose real values contribute to the randomness of the feature vector with a significantly increased uncertainty of the adversary, measured by mutual information, in comparison with linear correlation. Experimentally, the proposed technique has been shown to outperform related state-of-the art techniques recently proposed in the literature in terms of robustness with respect to image processing manipulations and geometric attacks.

  5. Perceptual-organizational characteristics of the Rorschach task.

    Science.gov (United States)

    Smith, Steven R; Bistis, Kimberly; Zahka, Nicole E; Blais, Mark A

    2007-09-01

    The present study was designed to begin to explore the perceptual and visuospatial organization required to respond to the Rorschach task. Previous research has shown a relative independence of Rorschach scores from other measures of neurocognitive functioning (e.g., Zillmer & Perry, 1996). However, many of the neuropsychological measures used in previous studies did not require the patient to organize a complex visuospatial stimulus in the same way that the Rorschach does. In this study, data from 27 children and adolescents administered the Rorschach and the Rey-Osterreith Complex Figure Test (ROCF) were examined. Results of analyses indicated that, accounting for age and Full Scale IQ, there were a number of significant relationships between accuracy of ROCF renditions and Rorschach measures of developmental quality and perceptual accuracy. Implications for the understanding the nature of the Rorschach response process and its utility in clinical neuropsychology are discussed.

  6. Perceptual differentiation and category effects in normal object recognition

    DEFF Research Database (Denmark)

    Gerlach, Christian; Law, I; Gade, A

    1999-01-01

    on artefacts in the difficult object decision tasks. Natural objects also recruited larger parts of the right inferior temporal and anterior fusiform gyri compared with artefacts as task difficulty increased. Differences in the amount of activation in these regions may reflect the greater perceptual......The purpose of the present PET study was (i) to investigate the neural correlates of object recognition, i.e. the matching of visual forms to memory, and (ii) to test the hypothesis that this process is more difficult for natural objects than for artefacts. This was done by using object decision...... tasks where subjects decided whether pictures represented real objects or non-objects. The object decision tasks differed in their difficulty (the degree of perceptual differentiation needed to perform them) and in the category of the real objects used (natural objects versus artefacts). A clear effect...

  7. The Facespan-the perceptual span for face recognition.

    Science.gov (United States)

    Papinutto, Michael; Lao, Junpeng; Ramon, Meike; Caldara, Roberto; Miellet, Sébastien

    2017-05-01

    In reading, the perceptual span is a well-established concept that refers to the amount of information that can be read in a single fixation. Surprisingly, despite extensive empirical interest in determining the perceptual strategies deployed to process faces and an ongoing debate regarding the factors or mechanism(s) underlying efficient face processing, the perceptual span for faces-the Facespan-remains undetermined. To address this issue, we applied the gaze-contingent Spotlight technique implemented in an old-new face recognition paradigm. This procedure allowed us to parametrically vary the amount of facial information available at a fixated location in order to determine the minimal aperture size at which face recognition performance plateaus. As expected, accuracy increased nonlinearly with spotlight size apertures. Analyses of Structural Similarity comparing the available information during spotlight and natural viewing conditions indicate that the Facespan-the minimum spatial extent of preserved facial information leading to comparable performance as in natural viewing-encompasses 7° of visual angle in our viewing conditions (size of the face stimulus: 15.6°; viewing distance: 70 cm), which represents 45% of the face. The present findings provide a benchmark for future investigations that will address if and how the Facespan is modulated by factors such as cultural, developmental, idiosyncratic, or task-related differences.

  8. Golden Perception: Simulating Perceptual Habits of the Past

    Directory of Open Access Journals (Sweden)

    Claus-Christian Carbon

    2013-09-01

    Full Text Available Medieval times were neither dark nor grey; natural light illuminated colourful scenes depicted in paintings through coloured windows and via artificial beeswax candlelight. When we enter, for example, a church to inspect its historic treasures ranging from mosaics to depictions of saints, we do this under quite unfavourable conditions; particularly as we mainly depend on artificial halogen, LED or fluorescent light for illuminating the desired object. As these light spectrums are different from the natural light conditions under which the old masterpieces were previously developed and perceived, the perceptual effects may dramatically differ, leading to significantly altered affective and cognitive processing. Different qualities of processing might particularly be triggered when perceiving artworks which deal with specific material prone to strong interaction with idiosyncratic light conditions, for instance gold-leafed surfaces that literally start to glow when lit by candles. We tested the perceptual experiences of a figurative piece of art which we created in 3 (foreground by 3 (background versions, illuminated under three different light conditions (daylight, coloured light and beeswax candlelight. Results demonstrated very different perceptual experiences with stunning effects for the interaction of the specific painting depicted on a gold-leafed background lit by candlelight.

  9. Studying real-world perceptual expertise.

    Science.gov (United States)

    Shen, Jianhong; Mack, Michael L; Palmeri, Thomas J

    2014-01-01

    Significant insights into visual cognition have come from studying real-world perceptual expertise. Many have previously reviewed empirical findings and theoretical developments from this work. Here we instead provide a brief perspective on approaches, considerations, and challenges to studying real-world perceptual expertise. We discuss factors like choosing to use real-world versus artificial object domains of expertise, selecting a target domain of real-world perceptual expertise, recruiting experts, evaluating their level of expertise, and experimentally testing experts in the lab and online. Throughout our perspective, we highlight expert birding (also called birdwatching) as an example, as it has been used as a target domain for over two decades in the perceptual expertise literature.

  10. Fostering perceptual skills in medical diagnosis

    NARCIS (Netherlands)

    Jarodzka, Halszka; Balslev, Thomas; Holmqvist, Kenneth; Nyström, Marcus; Scheiter, Katharina; Gerjets, Peter; Eika, Berit

    2011-01-01

    Jarodzka, H., Balslev, T., Holmqvist, K., Nyström, M., Scheiter, K., Gerjets, P., & Eika, B. (2011, April). Fostering perceptual skills in medical diagnosis. Meeting of the American Educational Research Association, New Orleans, USA.

  11. Fostering Perceptual Skills in Medical Diagnosis

    NARCIS (Netherlands)

    Jarodzka, Halszka; Balslev, Thomas; Holmqvist, Kenneth; Nyström, Marcus; Scheiter, Katharina; Gerjets, Peter; Eika, Berit

    2010-01-01

    Jarodzka, H., Balslev, T., Holmqvist, K., Nyström, M., Scheiter, K., Gerjets, P., & Eika, B. (2010, August). Fostering perceptual skills in medical diagnosis. Meeting of the EARLI SIG2 Text and Graphics Comprehension. Tübingen.

  12. Fostering Perceptual Skills in Medical Diagnosis

    NARCIS (Netherlands)

    Jarodzka, Halszka; Balslev, Thomas; Holmqvist, Kenneth; Nyström, Marcus; Scheiter, Katharina; Gerjets, Peter; Eika, Berit

    2010-01-01

    Jarodzka, H., Balslev, T., Holmqvist, K., Nyström, M., Scheiter, K., Gerjets, P., & Eika, B. (2010, August). Fostering perceptual skills in medical diagnosis. Meeting of the EARLI SIG2 Text and Graphics Comprehension. Tübingen.

  13. Fostering perceptual skills in medical diagnosis

    NARCIS (Netherlands)

    Jarodzka, Halszka; Balslev, Thomas; Holmqvist, Kenneth; Nyström, Marcus; Scheiter, Katharina; Gerjets, Peter; Eika, Berit

    2011-01-01

    Jarodzka, H., Balslev, T., Holmqvist, K., Nyström, M., Scheiter, K., Gerjets, P., & Eika, B. (2011, April). Fostering perceptual skills in medical diagnosis. Meeting of the American Educational Research Association, New Orleans, USA.

  14. Perceptual and performance biases in action selection

    OpenAIRE

    2008-01-01

    When we see an object in the world, there may be a large number of different ways to interact with that object. This large 'visuomotor space' can be constrained through affordances (perceptually available object properties defining potential uses), task demands and the actor's intentions. The effects of perceptual biases can be modified by performance factors, such as a limb's end-state-comfort (ESC; Rosenbaum et al. 1990). We investigated how two other potential performance biases affected i...

  15. Perceptual qualities and material classes.

    Science.gov (United States)

    Fleming, Roland W; Wiebel, Christiane; Gegenfurtner, Karl

    2013-07-11

    Under typical viewing conditions, we can easily group materials into distinct classes (e.g., woods, plastics, textiles). Additionally, we can also make many other judgments about material properties (e.g., hardness, rigidity, colorfulness). Although these two types of judgment (classification and inferring material properties) have different requirements, they likely facilitate one another. We conducted two experiments to investigate the interactions between material classification and judgments of material qualities in both the visual and semantic domains. In Experiment 1, nine students viewed 130 images of materials from 10 different classes. For each image, they rated nine subjective properties (glossiness, transparency, colorfulness, roughness, hardness, coldness, fragility, naturalness, prettiness). In Experiment 2, 65 subjects were given the verbal names of six material classes, which they rated in terms of 42 adjectives describing material qualities. In both experiments, there was notable agreement between subjects, and a relatively small number of factors (weighted combinations of different qualities) were substantially independent of one another. Despite the difficulty of classifying materials from images (Liu, Sharan, Adelson, & Rosenholtz, 2010), the different classes were well clustered in the feature space defined by the subjective ratings. K-means clustering could correctly identify class membership for over 90% of the samples, based on the average ratings across subjects. We also found a high degree of consistency between the two tasks, suggesting subjects access similar information about materials whether judging their qualities visually or from memory. Together, these findings show that perceptual qualities are well defined, distinct, and systematically related to material class membership.

  16. Stereotype threat prevents perceptual learning.

    Science.gov (United States)

    Rydell, Robert J; Shiffrin, Richard M; Boucher, Kathryn L; Van Loo, Katie; Rydell, Michael T

    2010-08-10

    Stereotype threat (ST) refers to a situation in which a member of a group fears that her or his performance will validate an existing negative performance stereotype, causing a decrease in performance. For example, reminding women of the stereotype "women are bad at math" causes them to perform more poorly on math questions from the SAT and GRE. Performance deficits can be of several types and be produced by several mechanisms. We show that ST prevents perceptual learning, defined in our task as an increasing rate of search for a target Chinese character in a display of such characters. Displays contained two or four characters and half of these contained a target. Search rate increased across a session of training for a control group of women, but not women under ST. Speeding of search is typically explained in terms of learned "popout" (automatic attraction of attention to a target). Did women under ST learn popout but fail to express it? Following training, the women were shown two colored squares and asked to choose the one with the greater color saturation. Superimposed on the squares were task-irrelevant Chinese characters. For women not trained under ST, the presence of a trained target on one square slowed responding, indicating that training had caused the learning of an attention response to targets. Women trained under ST showed no slowing, indicating that they had not learned such an attention response.

  17. Is it possible to assess visual–perceptual processes involved in writing through a tablet test?The new title is: Psychological and physiological processes in figure - tracing abilities measured using a tablet computer: a study with 7 - 9 - year - old children

    Directory of Open Access Journals (Sweden)

    Enrico Giammarco

    2016-10-01

    Full Text Available The present study investigated the use of a tablet computer to assess figure-tracing skills and their relationships with psychological (visual–perceptual processes, cognitive processes, handwriting skills and physiological (body mass index, isometric strength of arms parameters with school-children of second (7-8-year-olds and fourth (9-10-year-olds grades. We were also interested in gender differences. The task required tracing of geometric figures on a template, shown on a tablet screen in light grey, for the segments that make up the target figure, one at a time. This figure-tracing tablet test allows acquisition and automated analysis of four parameters: number of strokes (pen lift for each segment; oscillations of lines drawn with respect to reference lines; pressure of pen on tablet; and average speed of tracing. The results show a trade-off between speed and quality for the tablet parameters, with higher speed associated with more oscillations with respect to the reference lines, and lower number of strokes for each segment, in both male and female children. The involvement of visual–motor integration on the ability to reduce the oscillations in this tablet test was only seen for the male children, while both the male and female children showed a relationship between oscillations and more general/ abstract visual–spatial processes. These data confirm the role of visual–motor processes in this figure-tracing tablet test only for male children, while more general visual–spatial processes influence the performance in the tablet test for both sexes. We conclude that the test proposed is useful to screen for grapho-motor difficulties.

  18. Perceptual constancy in judgments of egocentric distance: prevailing binocular information

    Directory of Open Access Journals (Sweden)

    Elton H. Matsushima

    2003-01-01

    Full Text Available Binocular cues were considered the prevailing information on specifying depth since the beginning of vision research. In the present study, two perceptual responses, the classical verbal report and a more recent method, open-loop walking, were used to assess the role of binocular information for egocentric distance perception. In two cue conditions environments, full- and reduced-cue, observers judged and walked egocentric distances of stimuli presented at eye-level, under binocular or monocular viewing. Results indicated perceptual constancy for open-loop walking and binocular responses, as well as poor performances under strong degradation on visual information (reduced-cue under monocular viewing, thus presenting evidence to support the fundamental role of binocular information on perception of egocentric distances. Besides that, visually directed actions could be adequate measures of perceived distance, with a better reliability than verbal report, since they were quite free of intrusion of inferential processes and perceptual tendencies. In addition, reduced head movements, side-to-side as well as back and forth deflexion movements, could have contributed to a near perfect coupling between binocular disparity information and open-loop walking responses.

  19. Perceptual learning in the absence of task or stimulus specificity.

    Directory of Open Access Journals (Sweden)

    Ben S Webb

    Full Text Available Performance on most sensory tasks improves with practice. When making particularly challenging sensory judgments, perceptual improvements in performance are tightly coupled to the trained task and stimulus configuration. The form of this specificity is believed to provide a strong indication of which neurons are solving the task or encoding the learned stimulus. Here we systematically decouple task- and stimulus-mediated components of trained improvements in perceptual performance and show that neither provides an adequate description of the learning process. Twenty-four human subjects trained on a unique combination of task (three-element alignment or bisection and stimulus configuration (vertical or horizontal orientation. Before and after training, we measured subjects' performance on all four task-configuration combinations. What we demonstrate for the first time is that learning does actually transfer across both task and configuration provided there is a common spatial axis to the judgment. The critical factor underlying the transfer of learning effects is not the task or stimulus arrangements themselves, but rather the recruitment of commons sets of neurons most informative for making each perceptual judgment.

  20. Perceptual asymmetry reveals neural substrates underlying stereoscopic transparency.

    Science.gov (United States)

    Tsirlin, Inna; Allison, Robert S; Wilcox, Laurie M

    2012-02-01

    We describe a perceptual asymmetry found in stereoscopic perception of overlaid random-dot surfaces. Specifically, the minimum separation in depth needed to perceptually segregate two overlaid surfaces depended on the distribution of dots across the surfaces. With the total dot density fixed, significantly larger inter-plane disparities were required for perceptual segregation of the surfaces when the front surface had fewer dots than the back surface compared to when the back surface was the one with fewer dots. We propose that our results reflect an asymmetry in the signal strength of the front and back surfaces due to the assignment of the spaces between the dots to the back surface by disparity interpolation. This hypothesis was supported by the results of two experiments designed to reduce the imbalance in the neuronal response to the two surfaces. We modeled the psychophysical data with a network of inter-neural connections: excitatory within-disparity and inhibitory across disparity, where the spread of disparity was modulated according to figure-ground assignment. These psychophysical and computational findings suggest that stereoscopic transparency depends on both inter-neural interactions of disparity-tuned cells and higher-level processes governing figure ground segregation.

  1. Perceptual constancy in judgments of egocentric distance: prevailing binocular information

    Directory of Open Access Journals (Sweden)

    Matsushima Elton H.

    2003-01-01

    Full Text Available Binocular cues were considered the prevailing information on specifying depth since the beginning of vision research. In the present study, two perceptual responses, the classical verbal report and a more recent method, open-loop walking, were used to assess the role of binocular information for egocentric distance perception. In two cue conditions environments, full- and reduced-cue, observers judged and walked egocentric distances of stimuli presented at eye-level, under binocular or monocular viewing. Results indicated perceptual constancy for open-loop walking and binocular responses, as well as poor performances under strong degradation on visual information (reduced-cue under monocular viewing, thus presenting evidence to support the fundamental role of binocular information on perception of egocentric distances. Besides that, visually directed actions could be adequate measures of perceived distance, with a better reliability than verbal report, since they were quite free of intrusion of inferential processes and perceptual tendencies. In addition, reduced head movements, side-to-side as well as back and forth deflexion movements, could have contributed to a near perfect coupling between binocular disparity information and open-loop walking responses.

  2. The cerebellum and visual perceptual learning: evidence from a motion extrapolation task.

    Science.gov (United States)

    Deluca, Cristina; Golzar, Ashkan; Santandrea, Elisa; Lo Gerfo, Emanuele; Eštočinová, Jana; Moretto, Giuseppe; Fiaschi, Antonio; Panzeri, Marta; Mariotti, Caterina; Tinazzi, Michele; Chelazzi, Leonardo

    2014-09-01

    Visual perceptual learning is widely assumed to reflect plastic changes occurring along the cerebro-cortical visual pathways, including at the earliest stages of processing, though increasing evidence indicates that higher-level brain areas are also involved. Here we addressed the possibility that the cerebellum plays an important role in visual perceptual learning. Within the realm of motor control, the cerebellum supports learning of new skills and recalibration of motor commands when movement execution is consistently perturbed (adaptation). Growing evidence indicates that the cerebellum is also involved in cognition and mediates forms of cognitive learning. Therefore, the obvious question arises whether the cerebellum might play a similar role in learning and adaptation within the perceptual domain. We explored a possible deficit in visual perceptual learning (and adaptation) in patients with cerebellar damage using variants of a novel motion extrapolation, psychophysical paradigm. Compared to their age- and gender-matched controls, patients with focal damage to the posterior (but not the anterior) cerebellum showed strongly diminished learning, in terms of both rate and amount of improvement over time. Consistent with a double-dissociation pattern, patients with focal damage to the anterior cerebellum instead showed more severe clinical motor deficits, indicative of a distinct role of the anterior cerebellum in the motor domain. The collected evidence demonstrates that a pure form of slow-incremental visual perceptual learning is crucially dependent on the intact cerebellum, bearing the notion that the human cerebellum acts as a learning device for motor, cognitive and perceptual functions. We interpret the deficit in terms of an inability to fine-tune predictive models of the incoming flow of visual perceptual input over time. Moreover, our results suggest a strong dissociation between the role of different portions of the cerebellum in motor versus

  3. Predictive context influences perceptual selection during binocular rivalry

    Directory of Open Access Journals (Sweden)

    Rachel N Denison

    2011-12-01

    Full Text Available Prediction may be a fundamental principle of sensory processing: it has been proposed that the brain continuously generates predictions about forthcoming sensory information. However, little is known about how prediction contributes to the selection of a conscious percept from among competing alternatives. Here, we used binocular rivalry to investigate the effects of prediction on perceptual selection. In binocular rivalry, incompatible images presented to the two eyes result in a perceptual alternation between the images, even though the visual stimuli remain constant. If predictive signals influence the competition between neural representations of rivalrous images, this influence should generate a bias in perceptual selection that depends on predictive context. To manipulate predictive context, we developed a novel binocular rivalry paradigm in which rivalrous test images were immediately preceded by a sequence of context images presented identically to the two eyes. One of the test images was consistent with the preceding image sequence (it was the expected next image in the series, and the other was inconsistent (non-predicted. We found that human observers were more likely to perceive the consistent image at the onset of rivalry, suggesting that predictive context biased selection in favor of the predicted percept. This prediction effect was distinct from the effects of adaptation to stimuli presented before the binocular rivalry test. In addition, perceptual reports were speeded for predicted percepts relative to non-predicted percepts. These results suggest that predictive signals related to visual stimulus history exist at neural sites that can bias conscious perception during binocular rivalry. Our paradigm provides a new way to study how prior information and incoming sensory information combine to generate visual percepts.

  4. Continuous spatial representations in the olfactory bulb may reflect perceptual categories

    Directory of Open Access Journals (Sweden)

    Benjamin eAuffarth

    2011-10-01

    Full Text Available In sensory processing of odors, the olfactory bulb is an important relay station, where odor representations are noise-filtered, sharpened, and possibly re-organized. An organization by perceptual qualities has been found previously in the piriform cortex, however several recent studies indicate that the olfactory bulb code reflects behaviorally relevant dimensions spatially as well as at the population level. We apply a statistical analysis on 2-deoxyglucose images, taken over the entire bulb of glomerular layer of the rat, in order to see how the recognition of odors in the nose is translated into a map of odor quality in the brain. We first confirm previous studies that the first principal component could be related to pleasantness, however the next higher principal components are not directly clear. We then find mostly continuous spatial representations for perceptual categories. We compare the space spanned by spatial and population codes to human reports of perceptual similarity between odors and our results suggest that perceptual categories could be already embedded in glomerular activations and that spatial representations give a better match than population codes. This suggests that human and rat perceptual dimensions of odorant coding are related and indicates that perceptual qualities could be represented as continuous spatial codes of the olfactory bulb glomerulus population.

  5. A perceptual space of local image statistics.

    Science.gov (United States)

    Victor, Jonathan D; Thengone, Daniel J; Rizvi, Syed M; Conte, Mary M

    2015-12-01

    Local image statistics are important for visual analysis of textures, surfaces, and form. There are many kinds of local statistics, including those that capture luminance distributions, spatial contrast, oriented segments, and corners. While sensitivity to each of these kinds of statistics have been well-studied, much less is known about visual processing when multiple kinds of statistics are relevant, in large part because the dimensionality of the problem is high and different kinds of statistics interact. To approach this problem, we focused on binary images on a square lattice - a reduced set of stimuli which nevertheless taps many kinds of local statistics. In this 10-parameter space, we determined psychophysical thresholds to each kind of statistic (16 observers) and all of their pairwise combinations (4 observers). Sensitivities and isodiscrimination contours were consistent across observers. Isodiscrimination contours were elliptical, implying a quadratic interaction rule, which in turn determined ellipsoidal isodiscrimination surfaces in the full 10-dimensional space, and made predictions for sensitivities to complex combinations of statistics. These predictions, including the prediction of a combination of statistics that was metameric to random, were verified experimentally. Finally, check size had only a mild effect on sensitivities over the range from 2.8 to 14min, but sensitivities to second- and higher-order statistics was substantially lower at 1.4min. In sum, local image statistics form a perceptual space that is highly stereotyped across observers, in which different kinds of statistics interact according to simple rules.

  6. An Electrophysiological Index of Perceptual Goodness

    Science.gov (United States)

    Makin, Alexis D.J.; Wright, Damien; Rampone, Giulia; Palumbo, Letizia; Guest, Martin; Sheehan, Rhiannon; Cleaver, Helen; Bertamini, Marco

    2016-01-01

    A traditional line of work starting with the Gestalt school has shown that patterns vary in strength and salience; a difference in “Perceptual goodness.” The Holographic weight of evidence model quantifies goodness of visual regularities. The key formula states that W = E/N, where E is number of holographic identities in a pattern and N is number of elements. We tested whether W predicts the amplitude of the neural response to regularity in an extrastriate symmetry-sensitive network. We recorded an Event Related Potential (ERP) generated by symmetry called the Sustained Posterior Negativity (SPN). First, we reanalyzed the published work and found that W explained most variance in SPN amplitude. Then in four new studies, we confirmed specific predictions of the holographic model regarding 1) the differential effects of numerosity on reflection and repetition, 2) the similarity between reflection and Glass patterns, 3) multiple symmetries, and 4) symmetry and anti-symmetry. In all cases, the holographic approach predicted SPN amplitude remarkably well; particularly in an early window around 300–400 ms post stimulus onset. Although the holographic model was not conceived as a model of neural processing, it captures many details of the brain response to symmetry. PMID:27702812

  7. Anger perceptually and conceptually narrows cognitive scope.

    Science.gov (United States)

    Gable, Philip A; Poole, Bryan D; Harmon-Jones, Eddie

    2015-07-01

    For the last 50 years, research investigating the effect of emotions on scope of cognitive processing was based on models proposing that affective valence determined cognitive scope. More recently, our motivational intensity model suggests that this past work had confounded valence with motivational intensity. Research derived from this model supports the idea that motivational intensity, rather than affective valence, explains much of the variance emotions have on cognitive scope. However, the motivational intensity model is limited in that the empirical work has examined only positive affects high in approach and negative affects high in avoidance motivation. Thus, perhaps only approach-positive and avoidance-negative states narrow cognitive scope. The present research was designed to clarify these conceptual issues by examining the effect of anger, a negatively valenced approach-motivated state, on cognitive scope. Results revealed that anger narrowed attentional scope relative to a neutral state and that attentional narrowing to anger was similar to the attentional narrowing caused by high approach-motivated positive affects (Study 1). This narrowing of attention was related to trait approach motivation (Studies 2 and Study 3). Anger also narrowed conceptual cognitive categorization (Study 4). Narrowing of categorization related to participants' approach motivation toward anger stimuli. Together, these results suggest that anger, an approach-motivated negative affect, narrows perceptual and conceptual cognitive scope. More broadly, these results support the conceptual model that motivational intensity per se, rather than approach-positive and avoidance-negative states, causes a narrowing of cognitive scope.

  8. Generation and Perceptual Implicit Memory: Different Generation Tasks Produce Different Effects on Perceptual Priming

    Science.gov (United States)

    Mulligan, Neil W.; Dew, Ilana T. Z.

    2009-01-01

    The generation manipulation has been critical in delineating differences between implicit and explicit memory. In contrast to past research, the present experiments indicate that generating from a rhyme cue produces as much perceptual priming as does reading. This is demonstrated for 3 visual priming tasks: perceptual identification, word-fragment…

  9. Pupil size tracks perceptual content and surprise.

    Science.gov (United States)

    Kloosterman, Niels A; Meindertsma, Thomas; van Loon, Anouk M; Lamme, Victor A F; Bonneh, Yoram S; Donner, Tobias H

    2015-04-01

    Changes in pupil size at constant light levels reflect the activity of neuromodulatory brainstem centers that control global brain state. These endogenously driven pupil dynamics can be synchronized with cognitive acts. For example, the pupil dilates during the spontaneous switches of perception of a constant sensory input in bistable perceptual illusions. It is unknown whether this pupil dilation only indicates the occurrence of perceptual switches, or also their content. Here, we measured pupil diameter in human subjects reporting the subjective disappearance and re-appearance of a physically constant visual target surrounded by a moving pattern ('motion-induced blindness' illusion). We show that the pupil dilates during the perceptual switches in the illusion and a stimulus-evoked 'replay' of that illusion. Critically, the switch-related pupil dilation encodes perceptual content, with larger amplitude for disappearance than re-appearance. This difference in pupil response amplitude enables prediction of the type of report (disappearance vs. re-appearance) on individual switches (receiver-operating characteristic: 61%). The amplitude difference is independent of the relative durations of target-visible and target-invisible intervals and subjects' overt behavioral report of the perceptual switches. Further, we show that pupil dilation during the replay also scales with the level of surprise about the timing of switches, but there is no evidence for an interaction between the effects of surprise and perceptual content on the pupil response. Taken together, our results suggest that pupil-linked brain systems track both the content of, and surprise about, perceptual events.

  10. Perceptual continuation and depth in visual phantoms can be explained by perceptual transparency.

    Science.gov (United States)

    Kitaoka, A; Gyoba, J; Kawabata, H; Sakurai, K

    2001-01-01

    We try to explain perceptual continuation and depth in the visual-phantom illusion in terms of perceptual transparency. Perceptual continuation of inducing gratings across the occluder in stationary phantoms could be explained with unique transparency, a notion proposed by Anderson (1997 Perception 26 419-453). This view is consistent with a number of previous reports including that of McCourt (1994 Vision Research 34 1609-1617) who criticized the stationary phantom illusion from the viewpoint of his counterphase lightness induction or grating induction, which might involve invalid transparency. Here we confirm that the photopic phantom illusion (Kitaoka et al, 1999 Perception 28 825-834) really gives in-phase lightness induction and involves bistable transparency. It is thus suggested that perceptual continuation and depth in the visual-phantom illusion depend on perceptual transparency.

  11. Autism-specific covariation in perceptual performances: "g" or "p" factor?

    Directory of Open Access Journals (Sweden)

    Andrée-Anne S Meilleur

    Full Text Available BACKGROUND: Autistic perception is characterized by atypical and sometimes exceptional performance in several low- (e.g., discrimination and mid-level (e.g., pattern matching tasks in both visual and auditory domains. A factor that specifically affects perceptive abilities in autistic individuals should manifest as an autism-specific association between perceptual tasks. The first purpose of this study was to explore how perceptual performances are associated within or across processing levels and/or modalities. The second purpose was to determine if general intelligence, the major factor that accounts for covariation in task performances in non-autistic individuals, equally controls perceptual abilities in autistic individuals. METHODS: We asked 46 autistic individuals and 46 typically developing controls to perform four tasks measuring low- or mid-level visual or auditory processing. Intelligence was measured with the Wechsler's Intelligence Scale (FSIQ and Raven Progressive Matrices (RPM. We conducted linear regression models to compare task performances between groups and patterns of covariation between tasks. The addition of either Wechsler's FSIQ or RPM in the regression models controlled for the effects of intelligence. RESULTS: In typically developing individuals, most perceptual tasks were associated with intelligence measured either by RPM or Wechsler FSIQ. The residual covariation between unimodal tasks, i.e. covariation not explained by intelligence, could be explained by a modality-specific factor. In the autistic group, residual covariation revealed the presence of a plurimodal factor specific to autism. CONCLUSIONS: Autistic individuals show exceptional performance in some perceptual tasks. Here, we demonstrate the existence of specific, plurimodal covariation that does not dependent on general intelligence (or "g" factor. Instead, this residual covariation is accounted for by a common perceptual process (or "p" factor, which may

  12. You'd better think twice: post-decision perceptual confidence.

    Science.gov (United States)

    Hilgenstock, Raphael; Weiss, Thomas; Witte, Otto W

    2014-10-01

    Current findings suggest that confidence emerges only after decision making. However, the temporal and neural dynamics of the emergence of post-decision confidence--a metacognitive judgement--are not fully explored. To gain insight into the dynamics of post-decision confidence processing and to disentangle the processes underlying confidence judgements and decision making, we applied a tactile discrimination task during functional magnetic resonance imaging (fMRI). Our results revealed that reaction times to post-decision confidence depend on the level of confidence, suggesting that post-decision confidence in a perceptual choice is not processed in parallel to perceptual decision making. Moreover, we demonstrated by the parametric analysis of fMRI data that post-decisionally modelled confidence processing can be distinguished from processes related to decision making through anatomical location and through the pattern of neural activity. In contrast to perceptual decision making, post-decision confidence appears to be strictly allocated to a prefrontal network of brain regions, primarily the anterior and dorsolateral prefrontal cortex, areas that have been related to metacognition. Moreover, the processes underlying decision making and post-decision confidence may share recruitment of the dorsolateral prefrontal cortex, although the former probably has distinct functions with regard to processing of perceptual choices and post-decision confidence. Thus, this is the first fMRI study to disentangle the processes underlying post-decision confidence and decision making on behavioural, neuroanatomical, and neurofunctional levels. With regard to the temporal evolution of post-decision confidence, results of the present study provide strong support for the most recent theoretical models of human perceptual decision making, and thus provide implications for investigating confidence in perceptual paradigms.

  13. A new perspective on the perceptual selectivity of attention under load

    DEFF Research Database (Denmark)

    Giesbrecht, Barry; Sy, Jocelyn; Bundesen, Claus

    2014-01-01

    The human attention system helps us cope with a complex environment by supporting the selective processing of information relevant to our current goals. Understanding the perceptual, cognitive, and neural mechanisms that mediate selective attention is a core issue in cognitive neuroscience. One...... prominent model of selective attention, known as load theory, offers an account of how task demands determine when information is selected and an account of the efficiency of the selection process. However, load theory has several critical weaknesses that suggest that it is time for a new perspective. Here...... is integrated to provide efficient attentional selection and allocation of perceptual processing resources....

  14. How does the brain encode epistemic reliability? Perceptual presence, phenomenal transparency, and counterfactual richness.

    Science.gov (United States)

    Metzinger, Thomas

    2014-01-01

    Seth develops a convincing and detailed internalist alternative to the sensorimotor-contingency theory of perceptual phenomenology. However, there are remaining conceptual problems due to a semantic ambiguity in the notion of "presence" and the idea of "subjective veridicality." The current model should be integrated with the earlier idea that experiential "realness" and "mind-independence" are determined by the unavailability of earlier processing stages to attention. Counterfactual richness and attentional unavailability may both be indicators of the overall processing level currently achieved, a functional property that normally correlates with epistemic reliability. Perceptual presence as well as phenomenal transparency express epistemic reliability on the level of conscious processing.

  15. Retention of perceptual generalization of fear extinction.

    Science.gov (United States)

    Pappens, Meike; Schroijen, Mathias; Van den Bergh, Omer; Van Diest, Ilse

    2015-12-01

    Fear reduction obtained during a fear extinction procedure can generalize from the extinction stimulus to other perceptually similar stimuli. Perceptual generalization of fear extinction typically follows a perceptual gradient, with increasing levels of fear reduction the more a stimulus resembles the extinction stimulus. The current study aimed to investigate whether perceptual generalization of fear extinction can be observed also after a retention interval of 24h. Fear was acquired to three geometrical figures of different sizes (CS(+), CS1(+) and CS2(+)) by consistently pairing them with a short-lasting suffocation experience (US). Three other geometrical figures that were never followed by the US served as control stimuli (CS(-), CS1(-), CS2(-)). Next, only the CS(+) was extinguished by presenting it in the absence of the US. One day later, fear responses to all stimuli were assessed without any US-presentation. Outcome measures included startle blink EMG, skin conductance, US expectancy, respiratory rate and tidal volume. On day 2 spontaneous recovery of fear was observed in US expectancy and tidal volume, but not in the other outcomes. Evidence for the retention of fear extinction generalization was present in US expectancy and skin conductance, but a perceptual gradient in the retention of generalized fear extinction could not be observed.

  16. Perceptual Contrast Enhancement with Dynamic Range Adjustment

    Science.gov (United States)

    Zhang, Hong; Li, Yuecheng; Chen, Hao; Yuan, Ding; Sun, Mingui

    2013-01-01

    Recent years, although great efforts have been made to improve its performance, few Histogram equalization (HE) methods take human visual perception (HVP) into account explicitly. The human visual system (HVS) is more sensitive to edges than brightness. This paper proposes to take use of this nature intuitively and develops a perceptual contrast enhancement approach with dynamic range adjustment through histogram modification. The use of perceptual contrast connects the image enhancement problem with the HVS. To pre-condition the input image before the HE procedure is implemented, a perceptual contrast map (PCM) is constructed based on the modified Difference of Gaussian (DOG) algorithm. As a result, the contrast of the image is sharpened and high frequency noise is suppressed. A modified Clipped Histogram Equalization (CHE) is also developed which improves visual quality by automatically detecting the dynamic range of the image with improved perceptual contrast. Experimental results show that the new HE algorithm outperforms several state-of-the-art algorithms in improving perceptual contrast and enhancing details. In addition, the new algorithm is simple to implement, making it suitable for real-time applications. PMID:24339452

  17. Theta Brain Rhythms Index Perceptual Narrowing in Infant Speech Perception

    Directory of Open Access Journals (Sweden)

    Alexis eBosseler

    2013-10-01

    Full Text Available The development of speech perception shows a dramatic transition between infancy and adulthood. Between 6 and 12 months, infants’ initial ability to discriminate all phonetic units across the worlds’ languages narrows—native discrimination increases while nonnative discrimination shows a steep decline. We used magnetoencephalography (MEG to examine whether brain oscillations in the theta band (4-8Hz, reflecting increases in attention and cognitive effort, would provide a neural measure of the perceptual narrowing phenomenon in speech. Using an oddball paradigm, we varied speech stimuli in two dimensions, stimulus frequency (frequent vs. infrequent and language (native vs. nonnative speech syllables and tested 6-month-old infants, 12-month-old infants, and adults. We hypothesized that 6-month-old infants would show increased relative theta power (RTP for frequent syllables, regardless of their status as native or nonnative syllables, reflecting young infants’ attention and cognitive effort in response to highly frequent stimuli (statistical learning. In adults, we hypothesized increased RTP for nonnative stimuli, regardless of their presentation frequency, reflecting increased cognitive effort for nonnative phonetic categories. The 12-month-old infants were expected to show a pattern in transition, but one more similar to adults than to 6-month-old infants. The MEG brain rhythm results supported these hypotheses. We suggest that perceptual narrowing in speech perception is governed by an implicit learning process. This learning process involves an implicit shift in attention from frequent events (infants to learned categories (adults. Theta brain oscillatory activity may provide an index of perceptual narrowing beyond speech, and would offer a test of whether the early speech learning process is governed by domain-general or domain-specific processes.

  18. Subliminal Gestalt grouping: evidence of perceptual grouping by proximity and similarity in absence of conscious perception.

    Science.gov (United States)

    Montoro, Pedro R; Luna, Dolores; Ortells, Juan J

    2014-04-01

    Previous studies making use of indirect processing measures have shown that perceptual grouping can occur outside the focus of attention. However, no previous study has examined the possibility of subliminal processing of perceptual grouping. The present work steps forward in the study of perceptual organization, reporting direct evidence of subliminal processing of Gestalt patterns. In two masked priming experiments, Gestalt patterns grouped by proximity or similarity that induced either a horizontal or vertical global orientation of the stimuli were presented as masked primes and followed by visible targets that could be congruent or incongruent with the orientation of the primes. The results showed a reliable priming effect in the complete absence of prime awareness for both proximity and similarity grouping principles. These findings suggest that a phenomenal report of the Gestalt pattern is not mandatory to observe an effect on the response based on the global properties of Gestalt stimuli. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Multiple brain networks contribute to the acquisition of bias in perceptual decision-making

    Directory of Open Access Journals (Sweden)

    Mei-Yen eChen

    2015-03-01

    Full Text Available Bias occurs in perceptual decisions when the reward associated with a particular response dominates the sensory evidence in support of a choice. However, it remains unclear how this bias is acquired and once acquired, how it influences perceptual decision processes in the brain. We addressed these questions using model-based neuroimaging in a motion discrimination paradigm where contextual cues suggested which one of two options would receive higher rewards on each trial. We found that participants gradually learned to choose the higher-rewarded option in each context when making a perceptual decision. The amount of bias on each trial was fit well by a reinforcement-learning model that estimated the subjective value of each option within the current context. The brain mechanisms underlying this bias acquisition process were similar to those observed in reward-based decision tasks: prediction errors correlated with the fMRI signals in ventral striatum, dlPFC, and parietal cortex, whereas the amount of acquired bias correlated with activity in ventromedial prefrontal (vmPFC, dorsolateral frontal (dlPFC, and parietal cortices. Moreover, psychophysiological interaction analysis revealed that as bias increased, functional connectivity increased within multiple brain networks (dlPFC-vmPFC-visual, vmPFC-motor, and parietal-anterior-cingulate, suggesting that multiple mechanisms contribute to bias in perceptual decisions through integration of value processing with action, sensory, and control systems. These provide a novel link between the neural mechanisms underlying perceptual and economic decision-making.

  20. Linking cognitive and visual perceptual decline in healthy aging: The information degradation hypothesis.

    Science.gov (United States)

    Monge, Zachary A; Madden, David J

    2016-10-01

    Several hypotheses attempt to explain the relation between cognitive and perceptual decline in aging (e.g., common-cause, sensory deprivation, cognitive load on perception, information degradation). Unfortunately, the majority of past studies examining this association have used correlational analyses, not allowing for these hypotheses to be tested sufficiently. This correlational issue is especially relevant for the information degradation hypothesis, which states that degraded perceptual signal inputs, resulting from either age-related neurobiological processes (e.g., retinal degeneration) or experimental manipulations (e.g., reduced visual contrast), lead to errors in perceptual processing, which in turn may affect non-perceptual, higher-order cognitive processes. Even though the majority of studies examining the relation between age-related cognitive and perceptual decline have been correlational, we reviewed several studies demonstrating that visual manipulations affect both younger and older adults' cognitive performance, supporting the information degradation hypothesis and contradicting implications of other hypotheses (e.g., common-cause, sensory deprivation, cognitive load on perception). The reviewed evidence indicates the necessity to further examine the information degradation hypothesis in order to identify mechanisms underlying age-related cognitive decline.

  1. Visible digital watermarking system using perceptual models

    Science.gov (United States)

    Cheng, Qiang; Huang, Thomas S.

    2001-03-01

    This paper presents a visible watermarking system using perceptual models. %how and why A watermark image is overlaid translucently onto a primary image, for the purposes of immediate claim of copyright, instantaneous recognition of owner or creator, or deterrence to piracy of digital images or video. %perceptual The watermark is modulated by exploiting combined DCT-domain and DWT-domain perceptual models. % so that the watermark is visually uniform. The resulting watermarked image is visually pleasing and unobtrusive. The location, size and strength of the watermark vary randomly with the underlying image. The randomization makes the automatic removal of the watermark difficult even though the algorithm is known publicly but the key to the random sequence generator. The experiments demonstrate that the watermarked images have pleasant visual effect and strong robustness. The watermarking system can be used in copyright notification and protection.

  2. On Macroscopic Complexity and Perceptual Coding

    CERN Document Server

    Scoville, John

    2010-01-01

    While Shannon information establishes limits to the universal data compression of binary data, no existing theory provides an equivalent characterization of the lossy data compression algorithms prevalent in audiovisual media. The current paper proposes a mathematical framework for perceptual coding and inference which quantifies the complexity of objects indistinguishable to a particular observer. A definition of the complexity is presented and related to a generalization of Boltzmann entropy for these equivalence classes. When the classes are partitions of phase space, corresponding to classical observations, this is the proper Boltzmann entropy and the macroscopic complexity agrees with the Algorithmic Entropy. For general classes, the macroscopic complexity measure determines the optimal lossy compression of the data. Conversely, perceptual coding algorithms may be used to construct upper bounds on certain macroscopic complexities. Knowledge of these complexities, in turn, allows perceptual inference whic...

  3. Perceptual Templates Improvement through Action Video Game Playing and Comparison to Perceptual Learning

    Directory of Open Access Journals (Sweden)

    Ruyuan Zhang

    2011-05-01

    Full Text Available Action video game playing substantially improves visual performance; however, the source of this improvement remains unclear. Here we use the equivalent external noise technique to characterize the mechanism by which action video games may facilitate performance (Lu & Dosher, 1998. In first study, Action Video Game Players (VGPs and Non-Action Video Game Players (NVGPs performed a foveal orientation identification task at different external noise levels. VGPs showed lower thresholds than NVGPs with a marked difference at different noise levels. Perceptual Template Model fitting indicated that there were an 11% additive noise reduction and a 25% external noise exclusion. The causal effect of action video game playing was confirmed in a following 50 hour training study, This work establishes that playing action video games leads to robust internal addictive and external noise exclusion, consistent with the use of better matched perceptual templates. To investigate the discrepancy between our results and previous fovea perceptual learning research (Lu et al, 2004, same stimuli in previous experiment were used in perceptual learning experiment and we find same perceptual template improvement pattern. This suggest both action video game playing and perceptual learning could lead to better perceptual template.

  4. Security analysis of robust perceptual hashing

    Science.gov (United States)

    Koval, Oleksiy; Voloshynovskiy, Sviatoslav; Beekhof, Fokko; Pun, Thierry

    2008-02-01

    In this paper we considered the problem of security analysis of robust perceptual hashing in authentication application. The main goal of our analysis was to estimate the amount of trial efforts of the attacker, who is acting within the Kerckhoffs security principle, to reveal a secret key. For this purpose, we proposed to use Shannon equivocation that provides an estimate of complexity of the key search performed based on all available prior information and presented its application to security evaluation of particular robust perceptual hashing algorithms.

  5. A perceptual account of symbolic reasoning

    Directory of Open Access Journals (Sweden)

    David eLandy

    2014-04-01

    Full Text Available People can be taught to manipulate symbols according to formal mathematical and logical rules. Cognitive scientists have traditionally viewed this capacity—the capacity for symbolic reasoning—as grounded in the ability to internally represent numbers, logical relationships, and mathematical rules in an abstract, amodal fashion. We present an alternative view, portraying symbolic reasoning as a special kind of embodied reasoning in which arithmetic and logical formulae, externally represented as notations, serve as targets for powerful perceptual and sensorimotor systems. Although symbolic reasoning often conforms to abstract mathematical principles, it is typically implemented by perceptual and sensorimotor engagement with concrete environmental structures.

  6. Perceptual transparency in neon color spreading displays.

    Science.gov (United States)

    Ekroll, Vebjørn; Faul, Franz

    2002-08-01

    In neon color spreading displays, both a color illusion and perceptual transparency can be seen. In this study, we investigated the color conditions for the perception of transparency in such displays. It was found that the data are very well accounted for by a generalization of Metelli's (1970) episcotister model of balanced perceptual transparency to tristimulus values. This additive model correctly predicted which combinations of colors would lead to optimal impressions of transparency. Color combinations deviating slightly from the additive model also looked transparent, but less convincingly so.

  7. A perceptual account of symbolic reasoning.

    Science.gov (United States)

    Landy, David; Allen, Colin; Zednik, Carlos

    2014-01-01

    People can be taught to manipulate symbols according to formal mathematical and logical rules. Cognitive scientists have traditionally viewed this capacity-the capacity for symbolic reasoning-as grounded in the ability to internally represent numbers, logical relationships, and mathematical rules in an abstract, amodal fashion. We present an alternative view, portraying symbolic reasoning as a special kind of embodied reasoning in which arithmetic and logical formulae, externally represented as notations, serve as targets for powerful perceptual and sensorimotor systems. Although symbolic reasoning often conforms to abstract mathematical principles, it is typically implemented by perceptual and sensorimotor engagement with concrete environmental structures.

  8. Enhancement and Suppression in the Visual Field under Perceptual Load

    Directory of Open Access Journals (Sweden)

    Nathan A Parks

    2013-05-01

    Full Text Available The perceptual load theory of attention proposes that the degree to which visual distractors are processed is a function of the attentional demands of a task – greater demands increase filtering of irrelevant distractors. The spatial configuration of such filtering is unknown. Here, we used steady-state visual evoked potentials (SSVEPs in conjunction with time-domain event-related potentials (ERPs to investigate the distribution of load-induced distractor suppression and task-relevant enhancement in the visual field. Electroencephalogram (EEG was recorded while subjects performed a foveal go/no-go task that varied in perceptual load. Load-dependent distractor suppression was assessed by presenting a contrast reversing ring at one of three eccentricities (2°, 6°, or 11° during performance of the go/no-go task. Rings contrast reversed at 8.3 Hz, allowing load-dependent changes in distractor processing to be tracked in the frequency-domain. ERPs were calculated to the onset of stimuli in the load task to examine load-dependent modulation of task-relevant processing. Results showed that the amplitude of the distractor SSVEP (8.3Hz was attenuated under high perceptual load (relative to low load at the most proximal (2° eccentricity but not at more eccentric locations (6˚ or 11˚. Task-relevant ERPs revealed a significant increase in N1 amplitude under high load. These results are consistent with a center-surround configuration of load-induced enhancement and suppression in the visual field.

  9. Conceptual and Perceptual Priming and Dissociation in Chronic Posttraumatic Stress Disorder

    NARCIS (Netherlands)

    Lyttle, Nigel; Dorahy, Martin J.; Hanna, Donncha; Huntjens, Rafaele J. C.

    2010-01-01

    Cognitive models of posttraumatic stress disorder (PTSD) assert that memory processes play a significant role in PTSD (see e.g., Ehlers & Clark, 2000). Intrusive reexperiencing in PTSD has been linked to perceptual processing of trauma-related material with a corresponding hypothesized lack of

  10. Perceptual and Decisional Factors Influencing the Discrimination of Inversion in the Thatcher Illusion

    Science.gov (United States)

    Cornes, Katherine; Donnelly, Nick; Godwin, Hayward; Wenger, Michael J.

    2011-01-01

    The Thatcher illusion (Thompson, 1980) is considered to be a prototypical illustration of the notion that face perception is dependent on configural processes and representations. We explored this idea by examining the relative contributions of perceptual and decisional processes to the ability of observers to identify the orientation of two…

  11. Conceptual and Perceptual Priming and Dissociation in Chronic Posttraumatic Stress Disorder

    NARCIS (Netherlands)

    Lyttle, Nigel; Dorahy, Martin J.; Hanna, Donncha; Huntjens, Rafaele J. C.

    2010-01-01

    Cognitive models of posttraumatic stress disorder (PTSD) assert that memory processes play a significant role in PTSD (see e.g., Ehlers & Clark, 2000). Intrusive reexperiencing in PTSD has been linked to perceptual processing of trauma-related material with a corresponding hypothesized lack of conce

  12. Increased sensitivity to perceptual interference in adults with attention deficit hyperactivity disorder.

    Science.gov (United States)

    Stevens, Alexander A; Maron, Leeza; Nigg, Joel T; Cheung, Desmond; Ester, Edward F; Awh, Edward

    2012-05-01

    Difficulty with selective attention is a frequent complaint of adult patients with ADHD, but selective attention tasks have not provided robust evidence of attentional dysfunction in this group. Two experiments examine this puzzle by distinguishing between failures of spatial selection and problems due to sensitivity to perceptual interference. In Experiment 1, we measured the level of perceptual interference generated by targets in crowded displays with nearby distractors by comparing luminance thresholds in both distractor-present (noise) and distractor-absent (clean) displays. ADHD and control participants had comparable thresholds for clean displays, but ADHD individuals had elevated thresholds to crowded displays. These effects could be explained in two distinct ways. Deficits may have arisen from amplified visual interference in the noise condition, or from abnormalities in top-down attentional processes that reduce visual interference. Experiment 2 adjusted for individual perceptual differences with clean and noise displays, before measuring visual interference resolution at attended versus unattended locations. ADHD and control groups had comparable interference resolution at attended locations. These results suggest that perceptual interference rather than spatial attention deficits may account for some deficits in ADHD. This putative deficit in sensory function highlights a potential early-stage perceptual processing deficit in ADHD distinct from selective attention.

  13. 'If you are good, I get better': the role of social hierarchy in perceptual decision-making.

    Science.gov (United States)

    Santamaría-García, Hernando; Pannunzi, Mario; Ayneto, Alba; Deco, Gustavo; Sebastián-Gallés, Nuria

    2014-10-01

    So far, it was unclear if social hierarchy could influence sensory or perceptual cognitive processes. We evaluated the effects of social hierarchy on these processes using a basic visual perceptual decision task. We constructed a social hierarchy where participants performed the perceptual task separately with two covertly simulated players (superior, inferior). Participants were faster (better) when performing the discrimination task with the superior player. We studied the time course when social hierarchy was processed using event-related potentials and observed hierarchical effects even in early stages of sensory-perceptual processing, suggesting early top-down modulation by social hierarchy. Moreover, in a parallel analysis, we fitted a drift-diffusion model (DDM) to the results to evaluate the decision making process of this perceptual task in the context of a social hierarchy. Consistently, the DDM pointed to nondecision time (probably perceptual encoding) as the principal period influenced by social hierarchy. © The Author (2013). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  14. “Sightblind”: Perceptual Deficits in the “Intact” Visual Field

    Science.gov (United States)

    Bola, Michał; Gall, Carolin; Sabel, Bernhard A.

    2013-01-01

    Unilateral visual cortex lesions caused by stroke or trauma lead to blindness in contralateral visual field – a condition called homonymous hemianopia. Although the visual field area processed by the uninjured hemisphere is thought to be “intact,” it also exhibits marked perceptual deficits in contrast sensitivity, processing speed, and contour integration. Such patients are “sightblind” – their blindness reaches far beyond the primary scotoma. Studies showing perceptual deficits in patients’ intact fields are reviewed and implications of these findings are discussed. It is concluded that consequences of partial blindness are greater than previously thought, since perceptual deficits in the “intact” field likely contribute to subjective vision loss in patients with visual field defect. This has important implications for vision diagnosis and rehabilitation. PMID:23805126

  15. Beyond perceptual load and dilution: a review of the role of working memory in selective attention

    Directory of Open Access Journals (Sweden)

    Jan W. De Fockert

    2013-05-01

    Full Text Available The perceptual load and dilution models differ fundamentally in terms of the proposed mechanism underlying variation in distractibility during different perceptual conditions. However, both models predict that distracting information can be processed beyond perceptual processing under certain conditions, a prediction that is well-supported by the literature. Load theory proposes that in such cases, where perceptual task aspects do not allow for sufficient attentional selectivity, the maintenance of task-relevant processing depends on cognitive control mechanisms, including working memory. The key prediction is that working memory plays a role in keeping clear processing priorities in the face of potential distraction, and the evidence reviewed and evaluated in a meta-analysis here supports this claim, by showing that the processing of distracting information tends to be enhanced when load on a concurrent task of working memory is high. Low working memory capacity is similarly associated with greater distractor processing in selective attention, again suggesting that the unavailability of working memory during selective attention leads to an increase in distractibility. Together, these findings suggest that selective attention against distractors that are processed beyond perception depends on the availability of working memory. Possible mechanisms for the effects of working memory on selective attention are discussed.

  16. Brain Areas Consistently Linked to Individual Differences in Perceptual Decision-Making in Younger as Well as Older Adults before and after Training

    Science.gov (United States)

    Kuhn, Simone; Schmiedek, Florian; Schott, Bjorn; Ratcliff, Roger; Heinze, Hans-Jochen; Duzel, Emrah; Lindenberger, Ulman; Lovden, Martin

    2011-01-01

    Perceptual decision-making performance depends on several cognitive and neural processes. Here, we fit Ratcliff's diffusion model to accuracy data and reaction-time distributions from one numerical and one verbal two-choice perceptual-decision task to deconstruct these performance measures into the rate of evidence accumulation (i.e., drift rate),…

  17. Neural correlates of individual performance differences in resolving perceptual conflict.

    Directory of Open Access Journals (Sweden)

    Franziska Labrenz

    Full Text Available Attentional mechanisms are a crucial prerequisite to organize behavior. Most situations may be characterized by a 'competition' between salient, but irrelevant stimuli and less salient, relevant stimuli. In such situations top-down and bottom-up mechanisms interact with each other. In the present fMRI study, we examined how interindividual differences in resolving situations of perceptual conflict are reflected in brain networks mediating attentional selection. Doing so, we employed a change detection task in which subjects had to detect luminance changes in the presence and absence of competing distractors. The results show that good performers presented increased activation in the orbitofrontal cortex (BA 11, anterior cingulate (BA 25, inferior parietal lobule (BA 40 and visual areas V2 and V3 but decreased activation in BA 39. This suggests that areas mediating top-down attentional control are stronger activated in this group. Increased activity in visual areas reflects distinct neuronal enhancement relating to selective attentional mechanisms in order to solve the perceptual conflict. Opposed to good performers, brain areas activated by poor performers comprised the left inferior parietal lobule (BA 39 and fronto-parietal and visual regions were continuously deactivated, suggesting that poor performers perceive stronger conflict than good performers. Moreover, the suppression of neural activation in visual areas might indicate a strategy of poor performers to inhibit the processing of the irrelevant non-target feature. These results indicate that high sensitivity in perceptual areas and increased attentional control led to less conflict in stimulus processing and consequently to higher performance in competitive attentional selection.

  18. Neural correlates of individual performance differences in resolving perceptual conflict.

    Science.gov (United States)

    Labrenz, Franziska; Themann, Maria; Wascher, Edmund; Beste, Christian; Pfleiderer, Bettina

    2012-01-01

    Attentional mechanisms are a crucial prerequisite to organize behavior. Most situations may be characterized by a 'competition' between salient, but irrelevant stimuli and less salient, relevant stimuli. In such situations top-down and bottom-up mechanisms interact with each other. In the present fMRI study, we examined how interindividual differences in resolving situations of perceptual conflict are reflected in brain networks mediating attentional selection. Doing so, we employed a change detection task in which subjects had to detect luminance changes in the presence and absence of competing distractors. The results show that good performers presented increased activation in the orbitofrontal cortex (BA 11), anterior cingulate (BA 25), inferior parietal lobule (BA 40) and visual areas V2 and V3 but decreased activation in BA 39. This suggests that areas mediating top-down attentional control are stronger activated in this group. Increased activity in visual areas reflects distinct neuronal enhancement relating to selective attentional mechanisms in order to solve the perceptual conflict. Opposed to good performers, brain areas activated by poor performers comprised the left inferior parietal lobule (BA 39) and fronto-parietal and visual regions were continuously deactivated, suggesting that poor performers perceive stronger conflict than good performers. Moreover, the suppression of neural activation in visual areas might indicate a strategy of poor performers to inhibit the processing of the irrelevant non-target feature. These results indicate that high sensitivity in perceptual areas and increased attentional control led to less conflict in stimulus processing and consequently to higher performance in competitive attentional selection.

  19. Perceptual Discrimination In Static and Dynamic Noise: The Temporal Relation Between Perceptual Encoding and Decision-making

    Science.gov (United States)

    Ratcliff, Roger; Smith, Philip L.

    2010-01-01

    We report nine new experiments and reanalyze three published experiments that investigate factors affecting the time course of perceptual processing and its effects on subsequent decision making. Stimuli in letter discrimination and brightness discrimination tasks were degraded with static and dynamic noise. The onset and the time course of decision making were quantified by fitting the data with the diffusion model. Dynamic noise and, to a lesser extent, static noise, produced large shifts in the leading edge of the RT distribution in letter discrimination but had little effect in brightness discrimination. We interpret these shifts as changes in the onset of decision making. The different pattern of shifts in letter discrimination and brightness discrimination implies that decision making in the two tasks was affected differently by noise. The changes in RT distributions found with letter stimuli are inconsistent with the hypothesis that noise increases RTs to letter stimuli simply by reducing the rate at which evidence accumulates in the decision process. Instead, they imply that noise also delays the time at which evidence accumulation begins. The delay is shown not to be the result of strategic processes or the result of using different stimuli in different tasks. Our results imply, rather, that the onset of evidence accumulation in the decision process is time-locked to the perceptual encoding of the stimulus features needed to do the task. Two mechanisms that could produce this time-locking are described. PMID:20121313

  20. Fostering perceptual skills in medical diagnosis

    NARCIS (Netherlands)

    Jarodzka, Halszka; Balslev, Thomas; Holmqvist, Kenneth; Nyström, Marcus; Scheiter, Katharina; Gerjets, Peter; Eika, Berit

    2010-01-01

    Jarodzka, H., Balslev, T., Holmqvist, K., Nyström, M., Scheiter, K., Gerjets, P., & Eika, B. (2010, August). Fostering perceptual skills in medical diagnosis. Meeting of the EARLI SIG6/7 Instructional Design and Learning and Instruction with Computers, Ulm, Germany.

  1. Perceptual effects of overlapping curved glass

    NARCIS (Netherlands)

    Cruz, P.J.S.; Veer, F.A.; Carvalho, P.L.L.

    2010-01-01

    The application of glass in contemporary architecture explores perceptual phenomenon that intentionally change the way we experience space. SANAA'S recent work uses glass in a radical way, proposing a renewed approach to transparency. The Toledo Glass Pavilion, with most spaces defined by glass

  2. Perceptual effects of overlapping curved glass

    NARCIS (Netherlands)

    Cruz, P.J.S.; Veer, F.A.; Carvalho, P.L.L.

    2010-01-01

    The application of glass in contemporary architecture explores perceptual phenomenon that intentionally change the way we experience space. SANAA'S recent work uses glass in a radical way, proposing a renewed approach to transparency. The Toledo Glass Pavilion, with most spaces defined by glass wall

  3. Perceptual evaluation of different image fusion schemes

    NARCIS (Netherlands)

    Toet, A.; IJspeert, J.K.

    2001-01-01

    Human perceptual performance was tested with images of nighttime outdoor scenes. The scenes were registered both with a dual band (visual and near infrared) image intensified low-light CCD camera (DII) and with a thermal middle wavelength band (3-5 μm) infrared (IR) camera. Fused imagery was

  4. Modelling the Perceptual Components of Loudspeaker Distortion

    DEFF Research Database (Denmark)

    Olsen, Sune L.; Agerkvist, Finn T.; MacDonald, Ewen;

    2016-01-01

    While non-linear distortion in loudspeakers decreases audio quality, the perceptual consequences can vary substantially. This paper investigates the metric Rnonlin [1] which was developed to predict subjective measurements of sound quality in nonlinear systems. The generalisability of the metric...

  5. Adaptation and perceptual norms in color vision.

    Science.gov (United States)

    Webster, Michael A; Leonard, Deanne

    2008-11-01

    Many perceptual dimensions are thought to be represented relative to an average value or norm. Models of norm-based coding assume that the norm appears psychologically neutral because it reflects a neutral response in the underlying neural code. We tested this assumption in human color vision by asking how judgments of "white" are affected as neural responses are altered by adaptation. The adapting color was varied to determine the stimulus level that did not bias the observer's subjective white point. This level represents a response norm at the stages at which sensitivity is regulated by the adaptation, and we show that these response norms correspond to the perceptually neutral stimulus and that they can account for how the perception of white varies both across different observers and within the same observer at different locations in the visual field. We also show that individual differences in perceived white are reduced when observers are exposed to a common white adapting stimulus, suggesting that the perceptual differences are due in part to differences in how neural responses are normalized. These results suggest a close link between the norms for appearance and coding in color vision and illustrate a general paradigm for exploring this link in other perceptual domains.

  6. Perceptual analysis from confusions between vowels

    NARCIS (Netherlands)

    van der Kamp, L.J.T.; Pols, L.C.W.

    1971-01-01

    In an experiment on vowel identification confusions were obtained between 11 Dutch vowel sounds. To recover the perceptual configurations of the stimuli multidimensional scaling techniques were applied directly to the asymmetric confusion matrix, and to the symmetrized confusion matrix. In order to

  7. Well-Founded Belief and Perceptual Justification

    DEFF Research Database (Denmark)

    Broncano-Berrocal, Fernando

    2016-01-01

    According to Alan Millar, justified beliefs are well-founded beliefs. Millar cashes out the notion of well-foundedness in terms of having an adequate reason to believe something and believing it for that reason. To make his account of justified belief compatible with perceptual justification he a...

  8. Perceptual and performance biases in action selection

    NARCIS (Netherlands)

    Wilson, A.; van Bergen, E.; van Swieten, L.; Kent, S.; Mon-Williams, M.

    2008-01-01

    When we see an object in the world, there may be a large number of different ways to interact with that object. This large 'visuomotor space' can be constrained through affordances (perceptually available object properties defining potential uses), task demands and the actor's intentions. The effect

  9. Perceptual Load Influences Selective Attention across Development

    Science.gov (United States)

    Couperus, Jane W.

    2011-01-01

    Research suggests that visual selective attention develops across childhood. However, there is relatively little understanding of the neurological changes that accompany this development, particularly in the context of adult theories of selective attention, such as N. Lavie's (1995) perceptual load theory of attention. This study examined visual…

  10. Improving Perceptual Skills with 3-Dimensional Animations.

    Science.gov (United States)

    Johns, Janet Faye; Brander, Julianne Marie

    1998-01-01

    Describes three-dimensional computer aided design (CAD) models for every component in a representative mechanical system; the CAD models made it easy to generate 3-D animations that are ideal for teaching perceptual skills in multimedia computer-based technical training. Fifteen illustrations are provided. (AEF)

  11. Fostering perceptual skills in medical diagnosis

    NARCIS (Netherlands)

    Jarodzka, Halszka; Balslev, Thomas; Holmqvist, Kenneth; Nyström, Marcus; Scheiter, Katharina; Gerjets, Peter; Eika, Berit

    2010-01-01

    Jarodzka, H., Balslev, T., Holmqvist, K., Nyström, M., Scheiter, K., Gerjets, P., & Eika, B. (2010, August). Fostering perceptual skills in medical diagnosis. Meeting of the EARLI SIG6/7 Instructional Design and Learning and Instruction with Computers, Ulm, Germany.

  12. Improving Perceptual Skills with 3-Dimensional Animations.

    Science.gov (United States)

    Johns, Janet Faye; Brander, Julianne Marie

    1998-01-01

    Describes three-dimensional computer aided design (CAD) models for every component in a representative mechanical system; the CAD models made it easy to generate 3-D animations that are ideal for teaching perceptual skills in multimedia computer-based technical training. Fifteen illustrations are provided. (AEF)

  13. Perceptual dimensions for a dynamic tactile display

    Science.gov (United States)

    Pappas, Thrasyvoulos N.; Tartter, Vivien C.; Seward, Andrew G.; Genzer, Boris; Gourgey, Karen; Kretzschmar, Ilona

    2009-02-01

    We propose a new approach for converting graphical and pictorial information into tactile patterns that can be displayed in a static or dynamic tactile device. The key components of the proposed approach are (1) an algorithm that segments a scene into perceptually uniform segments; (2) a procedure for generating perceptually distinct tactile patterns; and (3) a mapping of the visual textures of the segments into tactile textures that convey similar concepts. We used existing digital halftoning and other techniques to generate a wide variety of tactile textures. We then conducted formal and informal subjective tests with sighted (but visually blocked) and visually-impaired subjects to determine the ability of human tactile perception to perceive differences among them. In addition to generating perceptually distinguishable tactile patterns, our goal is to identify significant dimensions of tactile texture perception, which will make it possible to map different visual attributes into independent tactile attributes. Our experimental results indicate that it is poosible to generate a number of perceptually distinguishable tactile patterns, and that different dimensions of tactile texture perception can indeed be identified.

  14. Physical-Perceptual Correspondence for Dynamic Thermal Stimulation.

    Science.gov (United States)

    Ho, Hsin-Ni; Sato, Katsunari; Kuroki, Scinob; Watanabe, Junji; Maeno, Takashi; Nishida, Shin'ya

    2017-01-01

    Thermal displays have been applied in various haptic applications, from material simulation to interpersonal communication; however, there is insufficient knowledge about the temporal processing in human thermal sense to provide a knowledge basis for thermal display design. In this study, we investigated the physical-perceptual correspondence for dynamic thermal stimulation to shed a light on the temporal processing of human thermal sense. In the experiments, participants reported subjective timings of the temperature onset and temperature peak of continuous temperature changes applied to the thenar eminence. We found that the physical-perceptual correspondence was not consistent for warm and cold stimulations. For warm stimulation, the subjective experience always came after the corresponding physical event. On the other hand, for cold stimulation, while the subjective onset always lagged the physical onset, the subjective temperature peak preceded the physical temperature peak. We analyzed these results in the framework of linear systems theory. The results suggest that the senses of warmth and cold have distinct temporal filtering properties, with the sense of cold being more transient than the sense of warmth. These findings advance our knowledge regarding temporal processing in human thermal sense and serve as a basis for thermal display design.

  15. A unified account of perceptual layering and surface appearance in terms of gamut relativity.

    Directory of Open Access Journals (Sweden)

    Tony Vladusich

    Full Text Available When we look at the world--or a graphical depiction of the world--we perceive surface materials (e.g. a ceramic black and white checkerboard independently of variations in illumination (e.g. shading or shadow and atmospheric media (e.g. clouds or smoke. Such percepts are partly based on the way physical surfaces and media reflect and transmit light and partly on the way the human visual system processes the complex patterns of light reaching the eye. One way to understand how these percepts arise is to assume that the visual system parses patterns of light into layered perceptual representations of surfaces, illumination and atmospheric media, one seen through another. Despite a great deal of previous experimental and modelling work on layered representation, however, a unified computational model of key perceptual demonstrations is still lacking. Here we present the first general computational model of perceptual layering and surface appearance--based on a boarder theoretical framework called gamut relativity--that is consistent with these demonstrations. The model (a qualitatively explains striking effects of perceptual transparency, figure-ground separation and lightness, (b quantitatively accounts for the role of stimulus- and task-driven constraints on perceptual matching performance, and (c unifies two prominent theoretical frameworks for understanding surface appearance. The model thereby provides novel insights into the remarkable capacity of the human visual system to represent and identify surface materials, illumination and atmospheric media, which can be exploited in computer graphics applications.

  16. A unified account of perceptual layering and surface appearance in terms of gamut relativity.

    Science.gov (United States)

    Vladusich, Tony; McDonnell, Mark D

    2014-01-01

    When we look at the world--or a graphical depiction of the world--we perceive surface materials (e.g. a ceramic black and white checkerboard) independently of variations in illumination (e.g. shading or shadow) and atmospheric media (e.g. clouds or smoke). Such percepts are partly based on the way physical surfaces and media reflect and transmit light and partly on the way the human visual system processes the complex patterns of light reaching the eye. One way to understand how these percepts arise is to assume that the visual system parses patterns of light into layered perceptual representations of surfaces, illumination and atmospheric media, one seen through another. Despite a great deal of previous experimental and modelling work on layered representation, however, a unified computational model of key perceptual demonstrations is still lacking. Here we present the first general computational model of perceptual layering and surface appearance--based on a boarder theoretical framework called gamut relativity--that is consistent with these demonstrations. The model (a) qualitatively explains striking effects of perceptual transparency, figure-ground separation and lightness, (b) quantitatively accounts for the role of stimulus- and task-driven constraints on perceptual matching performance, and (c) unifies two prominent theoretical frameworks for understanding surface appearance. The model thereby provides novel insights into the remarkable capacity of the human visual system to represent and identify surface materials, illumination and atmospheric media, which can be exploited in computer graphics applications.

  17. How active perception and attractor dynamics shape perceptual categorization: a computational model.

    Science.gov (United States)

    Catenacci Volpi, Nicola; Quinton, Jean Charles; Pezzulo, Giovanni

    2014-12-01

    We propose a computational model of perceptual categorization that fuses elements of grounded and sensorimotor theories of cognition with dynamic models of decision-making. We assume that category information consists in anticipated patterns of agent-environment interactions that can be elicited through overt or covert (simulated) eye movements, object manipulation, etc. This information is firstly encoded when category information is acquired, and then re-enacted during perceptual categorization. The perceptual categorization consists in a dynamic competition between attractors that encode the sensorimotor patterns typical of each category; action prediction success counts as "evidence" for a given category and contributes to falling into the corresponding attractor. The evidence accumulation process is guided by an active perception loop, and the active exploration of objects (e.g., visual exploration) aims at eliciting expected sensorimotor patterns that count as evidence for the object category. We present a computational model incorporating these elements and describing action prediction, active perception, and attractor dynamics as key elements of perceptual categorizations. We test the model in three simulated perceptual categorization tasks, and we discuss its relevance for grounded and sensorimotor theories of cognition.

  18. Prestimulus Alpha Power Influences Tactile Temporal Perceptual Discrimination and Confidence in Decisions.

    Science.gov (United States)

    Baumgarten, Thomas J; Schnitzler, Alfons; Lange, Joachim

    2016-03-01

    Recent studies have demonstrated that prestimulus alpha-band activity substantially influences perception of near-threshold stimuli. Here, we studied the influence of prestimulus alpha power fluctuations on temporal perceptual discrimination of suprathreshold tactile stimuli and subjects' confidence regarding their perceptual decisions. We investigated how prestimulus alpha-band power influences poststimulus decision-making variables. We presented electrical stimuli with different stimulus onset asynchronies (SOAs) to human subjects, and determined the SOA for which temporal perceptual discrimination varied on a trial-by-trial basis between perceiving 1 or 2 stimuli, prior to recording brain activity with magnetoencephalography. We found that low prestimulus alpha power in contralateral somatosensory and occipital areas predicts the veridical temporal perceptual discrimination of 2 stimuli. Additionally, prestimulus alpha power was negatively correlated with confidence ratings in correctly perceived trials, but positively correlated for incorrectly perceived trials. Finally, poststimulus event-related fields (ERFs) were modulated by prestimulus alpha power and reflect the result of a decisional process rather than physical stimulus parameters around ∼150 ms. These findings provide new insights into the link between spontaneous prestimulus alpha power fluctuations, temporal perceptual discrimination, decision making, and decisional confidence. The results suggest that prestimulus alpha power modulates perception and decisions on a continuous scale, as reflected in confidence ratings.

  19. Blinded by the load: attention, awareness and the role of perceptual load.

    Science.gov (United States)

    Lavie, Nilli; Beck, Diane M; Konstantinou, Nikos

    2014-05-05

    What is the relationship between attention and conscious awareness? Awareness sometimes appears to be restricted to the contents of focused attention, yet at other times irrelevant distractors will dominate awareness. This contradictory relationship has also been reflected in an abundance of discrepant research findings leading to an enduring controversy in cognitive psychology. Lavie's load theory of attention suggests that the puzzle can be solved by considering the role of perceptual load. Although distractors will intrude upon awareness in conditions of low load, awareness will be restricted to the content of focused attention when the attended information involves high perceptual load. Here, we review recent evidence for this proposal with an emphasis on the various subjective blindness phenomena, and their neural correlates, induced by conditions of high perceptual load. We also present novel findings that clarify the role of attention in the response to stimulus contrast. Overall, this article demonstrates a critical role for perceptual load across the spectrum of perceptual processes leading to awareness, from the very early sensory responses related to contrast detection to explicit recognition of semantic content.

  20. Reinforcement of perceptual inference: reward and punishment alter conscious visual perception during binocular rivalry

    Directory of Open Access Journals (Sweden)

    Gregor eWilbertz

    2014-12-01

    Full Text Available Perception is an inferential process, which becomes immediately evident when sensory information is conflicting or ambiguous and thus allows for more than one perceptual interpretation. Thinking the idea of perception as inference through to the end results in a blurring of boundaries between perception and action selection, as perceptual inference implies the construction of a percept as an active process. Here we therefore wondered whether perception shares a key characteristic of action selection, namely that it is shaped by reinforcement learning. In two behavioral experiments, we used binocular rivalry to examine whether perceptual inference can be influenced by the association of perceptual outcomes with reward or punishment, respectively, in analogy to instrumental conditioning. Binocular rivalry was evoked by two orthogonal grating stimuli presented to the two eyes, resulting in perceptual alternations between the two gratings. Perception was tracked indirectly and objectively through a target detection task, which allowed us to preclude potential reporting biases. Monetary rewards or punishments were given repeatedly during perception of only one of the two rivalling stimuli. We found an increase in dominance durations for the percept associated with reward, relative to the non-rewarded percept. In contrast, punishment led to an increase of the non-punished compared to a relative decrease of the punished percept. Our results show that perception shares key characteristics with action selection, in that it is influenced by reward and punishment in opposite directions, thus narrowing the gap between the conceptually separated domains of perception and action selection. We conclude that perceptual inference is an adaptive process that is shaped by its consequences.

  1. The perceptual domain: a taxonomy for allied health educators.

    Science.gov (United States)

    Hooker, E Z

    1981-08-01

    A taxonomy of the perceptual domain was proposed over a decade ago. It is hierarchical, as are the taxonomies in the cognitive, affective, and psychomotor domains. Perception involves extraction of information from presenting stimuli, and there is progression of information extraction as the hierarchy is ascended. Perceptual performance at the higher levels of the taxonomy assumes perceptual abilities at the lower levels. A modified version of the perceptual taxonomy applicable to allied health education is presented. Methods concerning application of the taxonomy are suggested. Use of the taxonomy of the perceptual domain would help allied health educators plan instruction and evaluate teaching.

  2. Perceptual importance analysis for H.264/AVC bit allocation

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The existing H.264/AVC rate control schemes rarely include the perceptual considerations. As a result, the improvements in visual quality are hardly comparable to those in peak signal-to-noise ratio (PSNR). In this paper, we propose a perceptual importance analysis scheme to accurately abstract the spatial and temporal perceptual characteristics of video contents. Then we perform bit allocation at macroblock (MB) level by adopting a perceptual mode decision scheme, which adaptively updates the Lagrangian multiplier for mode decision according to the perceptual importance of each MB. Simulation results show that the proposed scheme can efficiently reduce bit rates without visual quality degradation.

  3. Zooming in on the cause of the perceptual load effect in the go/no-go paradigm.

    Science.gov (United States)

    Chen, Zhe; Cave, Kyle R

    2016-08-01

    Perceptual load theory (Lavie, 2005) claims that attentional capacity that is not used for the current task is allocated to irrelevant distractors. It predicts that if the attentional demands of the current task are high, distractor interference will be low. One particularly powerful demonstration of perceptual load effects on distractor processing relies on a go/no-go cue that is interpreted by either simple feature detection or feature conjunction (Lavie, 1995). However, a possible alternative interpretation of these effects is that the differential degree of distractor processing is caused by how broadly attention is allocated (attentional zoom) rather than to perceptual load. In 4 experiments, we show that when stimuli are arranged to equalize the extent of spatial attention across conditions, distractor interference varies little whether cues are defined by a simple feature or a conjunction, and that the typical perceptual load effect emerges only when attentional zoom can covary with perceptual load. These results suggest that attentional zoom can account for the differential degree of distractor processing traditionally attributed to perceptual load in the go/no-go paradigm. They also provide new insight into how different factors interact to control distractor interference. (PsycINFO Database Record

  4. Perceptual anchoring in preschool children: not adultlike, but there.

    Directory of Open Access Journals (Sweden)

    Karen Banai

    Full Text Available BACKGROUND: Recent studies suggest that human auditory perception follows a prolonged developmental trajectory, sometimes continuing well into adolescence. Whereas both sensory and cognitive accounts have been proposed, the development of the ability to base current perceptual decisions on prior information, an ability that strongly benefits adult perception, has not been directly explored. Here we ask whether the auditory frequency discrimination of preschool children also improves when given the opportunity to use previously presented standard stimuli as perceptual anchors, and whether the magnitude of this anchoring effect undergoes developmental changes. METHODOLOGY/PRINCIPAL FINDINGS: Frequency discrimination was tested using two adaptive same/different protocols. In one protocol (with-reference, a repeated 1-kHz standard tone was presented repeatedly across trials. In the other (no-reference, no such repetitions occurred. Verbal memory and early reading skills were also evaluated to determine if the pattern of correlations between frequency discrimination, memory and literacy is similar to that previously reported in older children and adults. Preschool children were significantly more sensitive in the with-reference than in the no-reference condition, but the magnitude of this anchoring effect was smaller than that observed in adults. The pattern of correlations among discrimination thresholds, memory and literacy replicated previous reports in older children. CONCLUSIONS/SIGNIFICANCE: The processes allowing the use of context to form perceptual anchors are already functional among preschool children, albeit to a lesser extent than in adults. Nevertheless, immature anchoring cannot fully account for the poorer frequency discrimination abilities of young children. That anchoring is present among the majority of typically developing preschool children suggests that the anchoring deficits observed among individuals with dyslexia represent a

  5. The Neural Circuitry of Expertise: Perceptual Learning and Social Cognition

    Directory of Open Access Journals (Sweden)

    Michael eHarre

    2013-12-01

    Full Text Available Amongst the most significant questions we are confronted with today include the integration of the brain's micro-circuitry, our ability to build the complex social networks that underpin society and how our society impacts on our ecological environment. In trying to unravel these issues one place to begin is at the level of the individual: to consider how we accumulate information about our environment, how this information leads to decisions and how our individual decisions in turn create our social environment. While this is an enormous task, we may already have at hand many of the tools we need. This article is intended to review some of the recent results in neuro-cognitive research and show how they can be extended to two very specific types of expertise: perceptual expertise and social cognition. These two cognitive skills span a vast range of our genetic heritage. Perceptual expertise developed very early in our evolutionary history and is likely a highly developed part of all mammals' cognitive ability. On the other hand social cognition is most highly developed in humans in that we are able to maintain larger and more stable long term social connections with more behaviourally diverse individuals than any other species. To illustrate these ideas I will discuss board games as a toy model of social interactions as they include many of the relevant concepts: perceptual learning, decision-making, long term planning and understanding the mental states of other people. Using techniques that have been developed in mathematical psychology, I show that we can represent some of the key features of expertise using stochastic differential equations. Such models demonstrate how an expert's long exposure to a particular context influences the information they accumulate in order to make a decision.These processes are not confined to board games, we are all experts in our daily lives through long exposure to the many regularities of daily tasks and

  6. A perceptually tuned watermarking scheme for color images.

    Science.gov (United States)

    Chou, Chun-Hsien; Liu, Kuo-Cheng

    2010-11-01

    Transparency and robustness are two conflicting requirements demanded by digital image watermarking for copyright protection and many other purposes. A feasible way to simultaneously satisfy the two conflicting requirements is to embed high-strength watermark signals in the host signals that can accommodate the distortion due to watermark insertion as part of perceptual redundancy. The search of distortion-tolerable host signals for watermark insertion and the determination of watermark strength are hence crucial to the realization of a transparent yet robust watermark. This paper presents a color image watermarking scheme that hides watermark signals in most distortion-tolerable signals within three color channels of the host image without resulting in perceivable distortion. The distortion-tolerable host signals or the signals that possess high perceptual redundancy are sought in the wavelet domain for watermark insertion. A visual model based on the CIEDE2000 color difference equation is used to measure the perceptual redundancy inherent in each wavelet coefficient of the host image. By means of quantization index modulation, binary watermark signals are embedded in qualified wavelet coefficients. To reinforce the robustness, the watermark signals are repeated and permuted before embedding, and restored by the majority-vote decision making process in watermark extraction. Original images are not required in watermark extraction. Only a small amount of information including locations of qualified coefficients and the data associated with coefficient quantization is needed for watermark extraction. Experimental results show that the embedded watermark is transparent and quite robust in face of various attacks such as cropping, low-pass filtering, scaling, media filtering, white-noise addition as well as the JPEG and JPEG2000 coding at high compression ratios.

  7. The neural circuitry of expertise: perceptual learning and social cognition.

    Science.gov (United States)

    Harré, Michael

    2013-12-17

    Amongst the most significant questions we are confronted with today include the integration of the brain's micro-circuitry, our ability to build the complex social networks that underpin society and how our society impacts on our ecological environment. In trying to unravel these issues one place to begin is at the level of the individual: to consider how we accumulate information about our environment, how this information leads to decisions and how our individual decisions in turn create our social environment. While this is an enormous task, we may already have at hand many of the tools we need. This article is intended to review some of the recent results in neuro-cognitive research and show how they can be extended to two very specific and interrelated types of expertise: perceptual expertise and social cognition. These two cognitive skills span a vast range of our genetic heritage. Perceptual expertise developed very early in our evolutionary history and is a highly developed part of all mammals' cognitive ability. On the other hand social cognition is most highly developed in humans in that we are able to maintain larger and more stable long term social connections with more behaviorally diverse individuals than any other species. To illustrate these ideas I will discuss board games as a toy model of social interactions as they include many of the relevant concepts: perceptual learning, decision-making, long term planning and understanding the mental states of other people. Using techniques that have been developed in mathematical psychology, I show that we can represent some of the key features of expertise using stochastic differential equations (SDEs). Such models demonstrate how an expert's long exposure to a particular context influences the information they accumulate in order to make a decision.These processes are not confined to board games, we are all experts in our daily lives through long exposure to the many regularities of daily tasks and social

  8. The neural circuitry of expertise: perceptual learning and social cognition

    Science.gov (United States)

    Harré, Michael

    2013-01-01

    Amongst the most significant questions we are confronted with today include the integration of the brain's micro-circuitry, our ability to build the complex social networks that underpin society and how our society impacts on our ecological environment. In trying to unravel these issues one place to begin is at the level of the individual: to consider how we accumulate information about our environment, how this information leads to decisions and how our individual decisions in turn create our social environment. While this is an enormous task, we may already have at hand many of the tools we need. This article is intended to review some of the recent results in neuro-cognitive research and show how they can be extended to two very specific and interrelated types of expertise: perceptual expertise and social cognition. These two cognitive skills span a vast range of our genetic heritage. Perceptual expertise developed very early in our evolutionary history and is a highly developed part of all mammals' cognitive ability. On the other hand social cognition is most highly developed in humans in that we are able to maintain larger and more stable long term social connections with more behaviorally diverse individuals than any other species. To illustrate these ideas I will discuss board games as a toy model of social interactions as they include many of the relevant concepts: perceptual learning, decision-making, long term planning and understanding the mental states of other people. Using techniques that have been developed in mathematical psychology, I show that we can represent some of the key features of expertise using stochastic differential equations (SDEs). Such models demonstrate how an expert's long exposure to a particular context influences the information they accumulate in order to make a decision.These processes are not confined to board games, we are all experts in our daily lives through long exposure to the many regularities of daily tasks and social

  9. Acoustic processing of temporally modulated sounds in infants: evidence from a combined near-infrared spectroscopy and EEG study

    Directory of Open Access Journals (Sweden)

    Silke eTelkemeyer

    2011-04-01

    Full Text Available Speech perception requires rapid extraction of the linguistic content from the acoustic signal. The ability to efficiently process rapid changes in auditory information is important for decoding speech and thereby crucial during language acquisition. Investigating functional networks of speech perception in infancy might elucidate neuronal ensembles supporting perceptual abilities that gate language acquisition. Interhemispheric specializations for language have been demonstrated in infants. How these asymmetries are shaped by basic temporal acoustic properties is under debate. We recently provided evidence that newborns process non-linguistic sounds sharing temporal features with language in a differential and lateralized fashion. The present study used the same material while measuring brain responses of 6 and 3 month old infants using simultaneous recordings of electroencephalography (EEG and near-infrared spectroscopy (NIRS. NIRS reveals that the lateralization observed in newborns remains constant over the first months of life. While fast acoustic modulations elicit bilateral neuronal activations, slow modulations lead to right-lateralized responses. Additionally, auditory evoked potentials and oscillatory EEG responses show differential responses for fast and slow modulations indicating a sensitivity for temporal acoustic variations. Oscillatory responses reveal an effect of development, that is, 6 but not 3 month old infants show stronger theta-band desynchronization for slowly modulated sounds. Whether this developmental effect is due to increasing fine-grained perception for spectrotemporal sounds in general remains speculative. Our findings support the notion that a more general specialization for acoustic properties can be considered the basis for lateralization of speech perception. The results show that concurrent assessment of vascular based imaging and electrophysiological responses have great potential in the research on language

  10. Divided attention disrupts perceptual encoding during speech recognition.

    Science.gov (United States)

    Mattys, Sven L; Palmer, Shekeila D

    2015-03-01

    Performing a secondary task while listening to speech has a detrimental effect on speech processing, but the locus of the disruption within the speech system is poorly understood. Recent research has shown that cognitive load imposed by a concurrent visual task increases dependency on lexical knowledge during speech processing, but it does not affect lexical activation per se. This suggests that "lexical drift" under cognitive load occurs either as a post-lexical bias at the decisional level or as a secondary consequence of reduced perceptual sensitivity. This study aimed to adjudicate between these alternatives using a forced-choice task that required listeners to identify noise-degraded spoken words with or without the addition of a concurrent visual task. Adding cognitive load increased the likelihood that listeners would select a word acoustically similar to the target even though its frequency was lower than that of the target. Thus, there was no evidence that cognitive load led to a high-frequency response bias. Rather, cognitive load seems to disrupt sublexical encoding, possibly by impairing perceptual acuity at the auditory periphery.

  11. Nonverbal signals speak up: association between perceptual nonverbal dominance and emotional intelligence.

    Science.gov (United States)

    Jacob, Heike; Kreifelts, Benjamin; Brück, Carolin; Nizielski, Sophia; Schütz, Astrid; Wildgruber, Dirk

    2013-01-01

    Emotional communication uses verbal and nonverbal means. In case of conflicting signals, nonverbal information is assumed to have a stronger impact. It is unclear, however, whether perceptual nonverbal dominance varies between individuals and whether it is linked to emotional intelligence. Using audiovisual stimulus material comprising verbal and nonverbal emotional cues that were varied independently, perceptual nonverbal dominance profiles and their relations to emotional intelligence were examined. Nonverbal dominance was found in every participant, ranging from 55 to 100%. Moreover, emotional intelligence, particularly the ability to understand emotions, correlated positively with nonverbal dominance. Furthermore, higher overall emotional intelligence as well as a higher ability to understand emotions were linked to smaller reaction time differences between emotionally incongruent and congruent stimuli. The association between perceptual nonverbal dominance and emotional intelligence, and more specifically the ability to understand emotions, might reflect an adaptive process driven by the experience of higher authenticity in nonverbal cues.

  12. On marching to two different drummers - Perceptual aspects of the difficulties

    Science.gov (United States)

    Klapp, S. T.; Hill, M. D.; Tyler, J. G.; Martin, Z. E.; Jagacinski, R. J.

    1985-01-01

    Three experiments which reveal that the difficulties involved in processing conflicting rhythms occur when monitoring a stimuli and indicating termination of one rhythmic sequence or tapping with one hand are described. The relation between perceiving and acting in temporal tapping tasks is studied. The effects of varying temporal compatibility on perceptual monitoring and one-hand tapping are examined. It is observed that the difficulty of two-handed tapping to polyrhythms with two different tones decreases as pitch differences between tones decrease, and the difficulty of rhythmic coordination can be perceptually controlled. It is noted that the evaluation of polyrhythmic performance provides a useful means of examining the interactions of perceptual and motor organizations.

  13. Category and perceptual learning in subjects with treated Wilson's disease.

    Directory of Open Access Journals (Sweden)

    Pengjing Xu

    Full Text Available To explore the relationship between category and perceptual learning, we examined both category and perceptual learning in patients with treated Wilson's disease (WD, whose basal ganglia, known to be important in category learning, were damaged by the disease. We measured their learning rate and accuracy in rule-based and information-integration category learning, and magnitudes of perceptual learning in a wide range of external noise conditions, and compared the results with those of normal controls. The WD subjects exhibited deficits in both forms of category learning and in perceptual learning in high external noise. However, their perceptual learning in low external noise was relatively spared. There was no significant correlation between the two forms of category learning, nor between perceptual learning in low external noise and either form of category learning. Perceptual learning in high external noise was, however, significantly correlated with information-integration but not with rule-based category learning. The results suggest that there may be a strong link between information-integration category learning and perceptual learning in high external noise. Damage to brain structures that are important for information-integration category learning may lead to poor perceptual learning in high external noise, yet spare perceptual learning in low external noise. Perceptual learning in high and low external noise conditions may involve separate neural substrates.

  14. Category and Perceptual Learning in Subjects with Treated Wilson's Disease

    Science.gov (United States)

    Xu, Pengjing; Lu, Zhong-Lin; Wang, Xiaoping; Dosher, Barbara; Zhou, Jiangning; Zhang, Daren; Zhou, Yifeng

    2010-01-01

    To explore the relationship between category and perceptual learning, we examined both category and perceptual learning in patients with treated Wilson's disease (WD), whose basal ganglia, known to be important in category learning, were damaged by the disease. We measured their learning rate and accuracy in rule-based and information-integration category learning, and magnitudes of perceptual learning in a wide range of external noise conditions, and compared the results with those of normal controls. The WD subjects exhibited deficits in both forms of category learning and in perceptual learning in high external noise. However, their perceptual learning in low external noise was relatively spared. There was no significant correlation between the two forms of category learning, nor between perceptual learning in low external noise and either form of category learning. Perceptual learning in high external noise was, however, significantly correlated with information-integration but not with rule-based category learning. The results suggest that there may be a strong link between information-integration category learning and perceptual learning in high external noise. Damage to brain structures that are important for information-integration category learning may lead to poor perceptual learning in high external noise, yet spare perceptual learning in low external noise. Perceptual learning in high and low external noise conditions may involve separate neural substrates. PMID:20224790

  15. The acoustic and perceptual cues affecting melody segregation for listeners with a cochlear implant.

    Directory of Open Access Journals (Sweden)

    Jeremy eMarozeau

    2013-11-01

    Full Text Available Our ability to listen selectively to single sound sources in complex auditory environments is termed ‘auditory stream segregation.’ This ability is affected by peripheral disorders such as hearing loss, as well as plasticity in central processing such as occurs with musical training. Brain plasticity induced by musical training can enhance the ability to segregate sound, leading to improvements in a variety of auditory abilities. The melody segregation ability of 12 cochlear-implant recipients was tested using a new method to determine the perceptual distance needed to segregate a simple 4-note melody from a background of interleaved random-pitch distractor notes. In experiment 1, participants rated the difficulty of segregating the melody from distracter notes. Four physical properties of the distracter notes were changed. In experiment 2, listeners were asked to rate the dissimilarity between melody patterns whose notes differed on the four physical properties simultaneously. Multidimensional scaling analysis transformed the dissimilarity ratings into perceptual distances. Regression between physical and perceptual cues then derived the minimal perceptual distance needed to segregate the melody.The most efficient streaming cue for CI users was loudness. For the normal hearing listeners without musical backgrounds, a greater difference on the perceptual dimension correlated to the temporal envelope is needed for stream segregation in CI users. No differences in streaming efficiency were found between the perceptual dimensions linked to the F0 and the spectral envelope.Combined with our previous results in normally-hearing musicians and non-musicians, the results show that differences in training as well as differences in peripheral auditory processing (hearing impairment and the use of a hearing device influences the way that listeners use different acoustic cues for segregating interleaved musical streams.

  16. Effects of acute cortisol administration on perceptual priming of trauma-related material.

    Science.gov (United States)

    Holz, Elena; Lass-Hennemann, Johanna; Streb, Markus; Pfaltz, Monique; Michael, Tanja

    2014-01-01

    Intrusive memories are a hallmark symptom of posttraumatic stress disorder (PTSD). They reflect excessive and uncontrolled retrieval of the traumatic memory. Acute elevations of cortisol are known to impair the retrieval of already stored memory information. Thus, continuous cortisol administration might help in reducing intrusive memories in PTSD. Strong perceptual priming for neutral stimuli associated with a "traumatic" context has been shown to be one important learning mechanism that leads to intrusive memories. However, the memory modulating effects of cortisol have only been shown for explicit declarative memory processes. Thus, in our double blind, placebo controlled study we aimed to investigate whether cortisol influences perceptual priming of neutral stimuli that appeared in a "traumatic" context. Two groups of healthy volunteers (N = 160) watched either neutral or "traumatic" picture stories on a computer screen. Neutral objects were presented in between the pictures. Memory for these neutral objects was tested after 24 hours with a perceptual priming task and an explicit memory task. Prior to memory testing half of the participants in each group received 25 mg of cortisol, the other half received placebo. In the placebo group participants in the "traumatic" stories condition showed more perceptual priming for the neutral objects than participants in the neutral stories condition, indicating a strong perceptual priming effect for neutral stimuli presented in a "traumatic" context. In the cortisol group this effect was not present: Participants in the neutral stories and participants in the "traumatic" stories condition in the cortisol group showed comparable priming effects for the neutral objects. Our findings show that cortisol inhibits perceptual priming for neutral stimuli that appeared in a "traumatic" context. These findings indicate that cortisol influences PTSD-relevant memory processes and thus further support the idea that administration

  17. Effects of acute cortisol administration on perceptual priming of trauma-related material.

    Directory of Open Access Journals (Sweden)

    Elena Holz

    Full Text Available Intrusive memories are a hallmark symptom of posttraumatic stress disorder (PTSD. They reflect excessive and uncontrolled retrieval of the traumatic memory. Acute elevations of cortisol are known to impair the retrieval of already stored memory information. Thus, continuous cortisol administration might help in reducing intrusive memories in PTSD. Strong perceptual priming for neutral stimuli associated with a "traumatic" context has been shown to be one important learning mechanism that leads to intrusive memories. However, the memory modulating effects of cortisol have only been shown for explicit declarative memory processes. Thus, in our double blind, placebo controlled study we aimed to investigate whether cortisol influences perceptual priming of neutral stimuli that appeared in a "traumatic" context. Two groups of healthy volunteers (N = 160 watched either neutral or "traumatic" picture stories on a computer screen. Neutral objects were presented in between the pictures. Memory for these neutral objects was tested after 24 hours with a perceptual priming task and an explicit memory task. Prior to memory testing half of the participants in each group received 25 mg of cortisol, the other half received placebo. In the placebo group participants in the "traumatic" stories condition showed more perceptual priming for the neutral objects than participants in the neutral stories condition, indicating a strong perceptual priming effect for neutral stimuli presented in a "traumatic" context. In the cortisol group this effect was not present: Participants in the neutral stories and participants in the "traumatic" stories condition in the cortisol group showed comparable priming effects for the neutral objects. Our findings show that cortisol inhibits perceptual priming for neutral stimuli that appeared in a "traumatic" context. These findings indicate that cortisol influences PTSD-relevant memory processes and thus further support the idea

  18. Modelling the Emergence and Dynamics of Perceptual Organisation in Auditory Streaming

    Science.gov (United States)

    Mill, Robert W.; Bőhm, Tamás M.; Bendixen, Alexandra; Winkler, István; Denham, Susan L.

    2013-01-01

    Many sound sources can only be recognised from the pattern of sounds they emit, and not from the individual sound events that make up their emission sequences. Auditory scene analysis addresses the difficult task of interpreting the sound world in terms of an unknown number of discrete sound sources (causes) with possibly overlapping signals, and therefore of associating each event with the appropriate source. There are potentially many different ways in which incoming events can be assigned to different causes, which means that the auditory system has to choose between them. This problem has been studied for many years using the auditory streaming paradigm, and recently it has become apparent that instead of making one fixed perceptual decision, given sufficient time, auditory perception switches back and forth between the alternatives—a phenomenon known as perceptual bi- or multi-stability. We propose a new model of auditory scene analysis at the core of which is a process that seeks to discover predictable patterns in the ongoing sound sequence. Representations of predictable fragments are created on the fly, and are maintained, strengthened or weakened on the basis of their predictive success, and conflict with other representations. Auditory perceptual organisation emerges spontaneously from the nature of the competition between these representations. We present detailed comparisons between the model simulations and data from an auditory streaming experiment, and show that the model accounts for many important findings, including: the emergence of, and switching between, alternative organisations; the influence of stimulus parameters on perceptual dominance, switching rate and perceptual phase durations; and the build-up of auditory streaming. The principal contribution of the model is to show that a two-stage process of pattern discovery and competition between incompatible patterns can account for both the contents (perceptual organisations) and the

  19. Effects of Acute Cortisol Administration on Perceptual Priming of Trauma-Related Material

    Science.gov (United States)

    Streb, Markus; Pfaltz, Monique; Michael, Tanja

    2014-01-01

    Intrusive memories are a hallmark symptom of posttraumatic stress disorder (PTSD). They reflect excessive and uncontrolled retrieval of the traumatic memory. Acute elevations of cortisol are known to impair the retrieval of already stored memory information. Thus, continuous cortisol administration might help in reducing intrusive memories in PTSD. Strong perceptual priming for neutral stimuli associated with a “traumatic” context has been shown to be one important learning mechanism that leads to intrusive memories. However, the memory modulating effects of cortisol have only been shown for explicit declarative memory processes. Thus, in our double blind, placebo controlled study we aimed to investigate whether cortisol influences perceptual priming of neutral stimuli that appeared in a “traumatic” context. Two groups of healthy volunteers (N = 160) watched either neutral or “traumatic” picture stories on a computer screen. Neutral objects were presented in between the pictures. Memory for these neutral objects was tested after 24 hours with a perceptual priming task and an explicit memory task. Prior to memory testing half of the participants in each group received 25 mg of cortisol, the other half received placebo. In the placebo group participants in the “traumatic” stories condition showed more perceptual priming for the neutral objects than participants in the neutral stories condition, indicating a strong perceptual priming effect for neutral stimuli presented in a “traumatic” context. In the cortisol group this effect was not present: Participants in the neutral stories and participants in the “traumatic” stories condition in the cortisol group showed comparable priming effects for the neutral objects. Our findings show that cortisol inhibits perceptual priming for neutral stimuli that appeared in a “traumatic” context. These findings indicate that cortisol influences PTSD-relevant memory processes and thus further support

  20. ERP P1-N1 changes associated with Vernier perceptual learning and its location specificity and transfer.

    Science.gov (United States)

    Zhang, Gong-Liang; Cong, Lin-Juan; Song, Yan; Yu, Cong

    2013-03-26

    Our recent studies demonstrate that perceptual learning can transfer completely to untrained retinal locations upon proper training procedures, which suggests perceptual learning being a high-level learning process occurring beyond the retinotopic visual areas. We propose that whether learning is location specific depends on the functional connections between high-level learning and the sensory inputs corresponding to the untrained retinal locations. These inputs may be suppressed by intensive training and focused (spatial) attention on the trained location to obstruct learning transfer. Here we present event-related potential (ERP) evidence that Vernier perceptual learning and its transfer are associated with P1 reduction and N1 enhancement. However, location specificity is only associated with N1 suppression corresponding to the untrained retinal location. These results are consistent with our proposal that the blockage of top-down influences or functional connections and the inhibition of visual inputs corresponding to untrained locations may contribute to location specificity in perceptual learning.

  1. The role of selective attention in perceptual and affective priming

    Science.gov (United States)

    Stone, M.; Ladd, S. L.; Gabrieli, J. D.

    2000-01-01

    Two kinds of perceptual priming (word identification and word fragment completion), as well as preference priming (that may rely on special affective mechanisms) were examined after participants either read or named the colors of words and nonwords at study. Participants named the colors of words more slowly than the colors of nonwords, indicating that lexical processing of the words occurred at study. Nonetheless, priming on all three tests was lower after color naming than after reading, despite evidence of lexical processing during color naming shown by slower responses to words than to nonwords. These results indicate that selective attention to (rather than the mere processing of) letter string identity at study is important for subsequent repetition priming.

  2. The role of selective attention in perceptual and affective priming

    Science.gov (United States)

    Stone, M.; Ladd, S. L.; Gabrieli, J. D.

    2000-01-01

    Two kinds of perceptual priming (word identification and word fragment completion), as well as preference priming (that may rely on special affective mechanisms) were examined after participants either read or named the colors of words and nonwords at study. Participants named the colors of words more slowly than the colors of nonwords, indicating that lexical processing of the words occurred at study. Nonetheless, priming on all three tests was lower after color naming than after reading, despite evidence of lexical processing during color naming shown by slower responses to words than to nonwords. These results indicate that selective attention to (rather than the mere processing of) letter string identity at study is important for subsequent repetition priming.

  3. Probing the Perceptual and Cognitive Underpinnings of Braille Reading. An Estonian Population Study

    Science.gov (United States)

    Veispak, Anneli; Boets, Bart; Mannamaa, Mairi; Ghesquiere, Pol

    2012-01-01

    Similar to many sighted children who struggle with learning to read, a proportion of blind children have specific difficulties related to reading braille which cannot be easily explained. A lot of research has been conducted to investigate the perceptual and cognitive processes behind (impairments in) print reading. Very few studies, however, have…

  4. The impact of dissociation on perceptual priming and intrusions after listening to auditory narratives

    NARCIS (Netherlands)

    Dorahy, Martin J.; Peck, Rowan K.; Huntjens, Rafaele J. C.

    2016-01-01

    This study investigates the causal role of dissociation in intrusive memory development and possible underlying aberrant memory processes (e.g., increased perceptual priming). Using an audio-only adaption of the trauma film paradigm, we divided 60 participants into 3 conditions and presented them

  5. Acoustical and Perceptual Comparison of Noise Reduction and Compression in Hearing Aids

    Science.gov (United States)

    Brons, Inge; Houben, Rolph; Dreschler, Wouter A.

    2015-01-01

    Purpose: Noise reduction and dynamic-range compression are generally applied together in hearing aids but may have opposite effects on amplification. This study evaluated the acoustical and perceptual effects of separate and combined processing of noise reduction and compression. Design: Recordings of the output of 4 hearing aids for speech in…

  6. The influence of sleep deprivation and knowledge of results on perceptual encoding

    NARCIS (Netherlands)

    Steyvers, Franciscus J.J.M.

    1987-01-01

    This study investigates the way sleep deprivation effects on perceptual processes are modulated by knowledge of results (KR). In a choice-reaction task, signal quality was manipulated, combined with and without KR and under increasing levels of lack of sleep. It was found that the decrease of

  7. Acoustical and Perceptual Comparison of Noise Reduction and Compression in Hearing Aids

    Science.gov (United States)

    Brons, Inge; Houben, Rolph; Dreschler, Wouter A.

    2015-01-01

    Purpose: Noise reduction and dynamic-range compression are generally applied together in hearing aids but may have opposite effects on amplification. This study evaluated the acoustical and perceptual effects of separate and combined processing of noise reduction and compression. Design: Recordings of the output of 4 hearing aids for speech in…

  8. Intra and Intersensory Haptic Perception: Their Spatial and Perceptual-Motor Correlates.

    Science.gov (United States)

    Derevensky, Jeffrey L.; Petrushka, Tima L.

    This study investigated the relationship between intramodal and intermodal information processing and performance on traditional age appropriate tests of spatial and perceptual-motor abilities. The ability of 65 normal kindergarten, first grade and second grade children to match to either a tactile or a visual standard was assessed with a modified…

  9. The influence of sleep deprivation and knowledge of results on perceptual encoding

    NARCIS (Netherlands)

    Steyvers, Franciscus J.J.M.

    1987-01-01

    This study investigates the way sleep deprivation effects on perceptual processes are modulated by knowledge of results (KR). In a choice-reaction task, signal quality was manipulated, combined with and without KR and under increasing levels of lack of sleep. It was found that the decrease of perfor

  10. Diluting the Burden of Load: Perceptual Load Effects Are Simply Dilution Effects

    Science.gov (United States)

    Tsal, Yehoshua; Benoni, Hanna

    2010-01-01

    The substantial distractor interference obtained for small displays when the target appears alone is reduced in large displays when the target is embedded among neutral letters. This finding has been interpreted as reflecting low-load and high-load processing, respectively, thereby supporting the theory of perceptual load (Lavie & Tsal, 1994).…

  11. Deception in plants: mimicry or perceptual exploitation?

    Science.gov (United States)

    Schaefer, H Martin; Ruxton, Graeme D

    2009-12-01

    Mimicry involves adaptive resemblance between a mimic and a model. However, despite much recent research, it remains contentious in plants. Here, we review recent progress on studying deception by flowers, distinguishing between plants relying on mimicry to achieve pollination and those relying on the exploitation of the perceptual biases of animals. We disclose fundamental differences between both mechanisms and explain why the evolution of exploitation is less constrained than that of mimicry. Exploitation of perceptual biases might thus be a precursor for the gradual evolution of mimicry. Increasing knowledge on the sensory and cognitive filters in animals, and on the selective pressures that maintain them, should aid researchers in tracing the evolutionary dynamics of deception in plants.

  12. Zen Mountains: An Illusion of Perceptual Transparency

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    Susan G. Wardle

    2015-04-01

    Full Text Available The human visual system is usually very successful in segmenting complex natural scenes. During a trip to the Nepalese Himalayas, we observed an impossible example of Nature's beauty: “transparent” mountains. The scene is captured in a photograph in which a pair of mountain peaks viewed in the far distance appear to be transparent. This illusion results from a fortuitous combination of lighting and scene conditions, which induce an erroneous integration of multiple segmentation cues. The illusion unites three classic principles of visual perception: Metelli's constraints for perceptual transparency, the Gestalt principle of good continuation, and depth from contrast and atmospheric scattering. This real-world “failure” of scene segmentation reinforces how ingeniously the human visual system typically integrates complex sources of perceptual information using heuristics based on likelihood as shortcuts to veridical perception.

  13. Monocular depth effects on perceptual fading.

    Science.gov (United States)

    Hsu, Li-Chuan; Kramer, Peter; Yeh, Su-Ling

    2010-08-06

    After prolonged viewing, a static target among moving non-targets is perceived to repeatedly disappear and reappear. An uncrossed stereoscopic disparity of the target facilitates this Motion-Induced Blindness (MIB). Here we test whether monocular depth cues can affect MIB too, and whether they can also affect perceptual fading in static displays. Experiment 1 reveals an effect of interposition: more MIB when the target appears partially covered by, than when it appears to cover, its surroundings. Experiment 2 shows that the effect is indeed due to interposition and not to the target's contours. Experiment 3 induces depth with the watercolor illusion and replicates Experiment 1. Experiments 4 and 5 replicate Experiments 1 and 3 without the use of motion. Since almost any stimulus contains a monocular depth cue, we conclude that perceived depth affects perceptual fading in almost any stimulus, whether dynamic or static. Copyright 2010 Elsevier Ltd. All rights reserved.

  14. From Perceptual Categories to Concepts: What Develops?

    Science.gov (United States)

    Sloutsky, Vladimir M

    2010-09-01

    People are remarkably smart: they use language, possess complex motor skills, make non-trivial inferences, develop and use scientific theories, make laws, and adapt to complex dynamic environments. Much of this knowledge requires concepts and this paper focuses on how people acquire concepts. It is argued that conceptual development progresses from simple perceptual grouping to highly abstract scientific concepts. This proposal of conceptual development has four parts. First, it is argued that categories in the world have different structure. Second, there might be different learning systems (sub-served by different brain mechanisms) that evolved to learn categories of differing structures. Third, these systems exhibit differential maturational course, which affects how categories of different structures are learned in the course of development. And finally, an interaction of these components may result in the developmental transition from perceptual groupings to more abstract concepts. This paper reviews a large body of empirical evidence supporting this proposal.

  15. Direct Relationship Between Perceptual and Motor Variability

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    Liston, Dorion B.; Stone, Leland S.

    2010-01-01

    The time that elapses between stimulus onset and the onset of a saccadic eye movement is longer and more variable than can be explained by neural transmission times and synaptic delays (Carpenter, 1981, in: Eye Movements: Cognition & Visual Perception, Earlbaum). In theory, noise underlying response-time (RT) variability could arise at any point along the sensorimotor cascade, from sensory noise arising Vvithin the early visual processing shared Vvith perception to noise in the motor criterion or commands necessary to trigger movements. These two loci for internal noise can be distinguished empirically; sensory internal noise predicts that response time Vvill correlate Vvith perceived stimulus magnitude whereas motor internal noise predicts no such correlation. Methods. We used the data described by Liston and Stone (2008, JNS 28:13866-13875), in which subjects performed a 2AFC saccadic brightness discrimination task and the perceived brightness of the chosen stimulus was then quantified in a second 21FC perceptual task. Results. We binned each subject's data into quartiles for both signal strength (from dimmest to brightest) and RT (from slowest to fastest) and analyzed the trends in perceived brightness. We found significant effects of both signal strength (as expected) and RT on normalized perceived brightness (both p less than 0.0001, 2-way ANOVA), without significant interaction (p = 0.95, 2-way ANOVA). A plot of normalized perceived brightness versus normalized RT show's that more than half of the variance was shared (r2 = 0.56, P less than 0.0001). To rule out any possibility that some signal-strength related artifact was generating this effect, we ran a control analysis on pairs of trials with repeated presentations of identical stimuli and found that stimuli are perceived to be brighter on trials with faster saccades (p less than 0.001, paired t-test across subjects). Conclusion. These data show that shared early visual internal noise jitters perceived

  16. 论文学翻译中的非文本因素--以《吉檀迦利》冰心译本为例%On Non-linguistic Factors in Literary Translation--A Case Study of Bing Xin’s Translation of Gitanjali

    Institute of Scientific and Technical Information of China (English)

    林嘉新

    2014-01-01

    Gitanjali, one of the best poetry anthologies in the world, marks the summit of Tagore’s poetry writing. It has been translated into Chinese language several times by different translators, which, to some extent, reflects the popularity of this collection in China. Borrowing the three factors in Lefevere’s Rewriting Theory, and putting the subjective conditions of translators into consideration, this paper analyzes and discusses the main non-linguistic determinants of Bing Xin’s translation, and as a result works out the important status and role of non-linguistic factors in the producion of Bing Xin’s translation of Gitanjali. The paper also provides reference for the future research of non-linguistic factors in literary translation.%《吉檀迦利》是泰戈尔诗歌创作的高峰。在中国,它曾在不同时期被不同译者多次翻译成汉语。研究中借用勒弗维尔的“改写理论”中非文本因素思想,对文学翻译中的主要非文本因素进行划分,据此分析和讨论《吉檀迦利》冰心译本,论证非文本因素在《吉檀迦利》冰心译本产生的过程中的重要地位和作用。

  17. Atypicalities in Perceptual Adaptation in Autism Do Not Extend to Perceptual Causality

    Science.gov (United States)

    Karaminis, Themelis; Turi, Marco; Neil, Louise; Badcock, Nicholas A.; Burr, David; Pellicano, Elizabeth

    2015-01-01

    A recent study showed that adaptation to causal events (collisions) in adults caused subsequent events to be less likely perceived as causal. In this study, we examined if a similar negative adaptation effect for perceptual causality occurs in children, both typically developing and with autism. Previous studies have reported diminished adaptation for face identity, facial configuration and gaze direction in children with autism. To test whether diminished adaptive coding extends beyond high-level social stimuli (such as faces) and could be a general property of autistic perception, we developed a child-friendly paradigm for adaptation of perceptual causality. We compared the performance of 22 children with autism with 22 typically developing children, individually matched on age and ability (IQ scores). We found significant and equally robust adaptation aftereffects for perceptual causality in both groups. There were also no differences between the two groups in their attention, as revealed by reaction times and accuracy in a change-detection task. These findings suggest that adaptation to perceptual causality in autism is largely similar to typical development and, further, that diminished adaptive coding might not be a general characteristic of autism at low levels of the perceptual hierarchy, constraining existing theories of adaptation in autism. PMID:25774507

  18. Atypicalities in perceptual adaptation in autism do not extend to perceptual causality.

    Directory of Open Access Journals (Sweden)

    Themelis Karaminis

    Full Text Available A recent study showed that adaptation to causal events (collisions in adults caused subsequent events to be less likely perceived as causal. In this study, we examined if a similar negative adaptation effect for perceptual causality occurs in children, both typically developing and with autism. Previous studies have reported diminished adaptation for face identity, facial configuration and gaze direction in children with autism. To test whether diminished adaptive coding extends beyond high-level social stimuli (such as faces and could be a general property of autistic perception, we developed a child-friendly paradigm for adaptation of perceptual causality. We compared the performance of 22 children with autism with 22 typically developing children, individually matched on age and ability (IQ scores. We found significant and equally robust adaptation aftereffects for perceptual causality in both groups. There were also no differences between the two groups in their attention, as revealed by reaction times and accuracy in a change-detection task. These findings suggest that adaptation to perceptual causality in autism is largely similar to typical development and, further, that diminished adaptive coding might not be a general characteristic of autism at low levels of the perceptual hierarchy, constraining existing theories of adaptation in autism.

  19. Centration-distortion error: a criterion of perceptual dysfunction.

    Science.gov (United States)

    Mecke, V

    This was a study to determine whether centration, as a perceptual process, could be a criterion for differentiating between neurologically impaired and emotionally disturbed children. Centration was defined by Piaget as a prolonged involuntary attachment of a sensory modality to one part of a field, causing perceptual errors of exaggerations and distortions. It is hypothesized that centration would affect motor behavior, producing effects on drawing tasks characterized by separation of designs or their parts, coincident with distortions of the figures drawn. The neurologically impaired children were identified as having primary difficulties with perception whereas the emotionally disturbed children would have primary difficulties with intellection. The centration-distortion error would characterize the drawing of the neurologically impaired but not those of the emotionally disturbed children. A sample of 44 children was selected, each with EEG records, psychological tests and psychiatric interviews used as differential criteria for the groups. Eleven children were diagnosed as having minimal brain damage, 33 as emotionally disturbed. Three psychologists scored the Bender Gestalt tests, blind, for indicators of brain injury and emotional disturbance as defined by Koppitz' criteria, and for the centration-distortion error. The hypothesis was upheld at the .001 level of confidence, validating an earlier pilot study.

  20. Internal signal correlates neural populations and biases perceptual decision reports

    Science.gov (United States)

    Carnevale, Federico; de Lafuente, Victor; Romo, Ranulfo; Parga, Néstor

    2012-01-01

    In perceptual decision-making tasks the activity of neurons in frontal and posterior parietal cortices covaries more with perceptual reports than with the physical properties of stimuli. This relationship is revealed when subjects have to make behavioral choices about weak or uncertain stimuli. If knowledge about stimulus onset time is available, decision making can be based on accumulation of sensory evidence. However, the time of stimulus onset or even its very presence is often ambiguous. By analyzing firing rates and correlated variability of frontal lobe neurons while monkeys perform a vibrotactile detection task, we show that behavioral outcomes are crucially affected by the state of cortical networks before stimulus onset times. The results suggest that sensory detection is partly due to a purely internal signal whereas the stimulus, if finally applied, adds a contribution to this initial processing later on. The probability to detect or miss the stimulus can thus be explained as the combined effect of this variable internal signal and the sensory evidence. PMID:23112203

  1. The neural subjective frame: from bodily signals to perceptual consciousness.

    Science.gov (United States)

    Park, Hyeong-Dong; Tallon-Baudry, Catherine

    2014-05-05

    The report 'I saw the stimulus' operationally defines visual consciousness, but where does the 'I' come from? To account for the subjective dimension of perceptual experience, we introduce the concept of the neural subjective frame. The neural subjective frame would be based on the constantly updated neural maps of the internal state of the body and constitute a neural referential from which first person experience can be created. We propose to root the neural subjective frame in the neural representation of visceral information which is transmitted through multiple anatomical pathways to a number of target sites, including posterior insula, ventral anterior cingulate cortex, amygdala and somatosensory cortex. We review existing experimental evidence showing that the processing of external stimuli can interact with visceral function. The neural subjective frame is a low-level building block of subjective experience which is not explicitly experienced by itself which is necessary but not sufficient for perceptual experience. It could also underlie other types of subjective experiences such as self-consciousness and emotional feelings. Because the neural subjective frame is tightly linked to homeostatic regulations involved in vigilance, it could also make a link between state and content consciousness.

  2. Short term synaptic depression improves information transfer in perceptual multistability

    Directory of Open Access Journals (Sweden)

    Zachary P Kilpatrick

    2013-07-01

    Full Text Available Competitive neural networks are often used to model the dynamics of perceptual bistability. Switching between percepts can occur through fluctuations and/or a slow adaptive process. Here, we analyze switching statistics in competitive networks with short term synaptic depression and noise. We start by analyzing a ring model that yields spatially structured solutions and complement this with a study of a space-free network whose populations are coupled with mutual inhibition. Dominance times arising from depression driven switching can be approximated using a separation of timescales in the ring and space-free model. For purely noise-driven switching, we derive approximate energy functions to justify how dominance times are exponentially related to input strength. We also show that a combination of depression and noise generates realistic distributions of dominance times. Unimodal functions of dominance times are more easily told apart by sampling, so switches induced by synaptic depression induced provide more information about stimuli than noise-driven switching. Finally, we analyze a competitive network model of perceptual tristability, showing depression generates a history-dependence in dominance switching.

  3. Transcranial Magnetic Stimulation Reveals Intrinsic Perceptual and Attentional Rhythms

    Science.gov (United States)

    Dugué, Laura; VanRullen, Rufin

    2017-01-01

    Oscillatory brain activity has functional relevance for perceptual and cognitive processes, as proven by numerous electrophysiology studies accumulating over the years. However, only within the past two decades have researchers been able to study the causal role of such oscillations using transcranial magnetic stimulation (TMS) technology. Two complementary approaches exist. A majority of research employs rhythmic TMS (rTMS) to entrain oscillatory activity and investigate its effect on targeted brain functions. On the other hand, single pulses of TMS (spTMS) that can be delivered with a high spatio-temporal resolution, can be used to precisely probe the state of the system. In this mini-review, we concentrate on this second approach. We argue that, with no a priori hypothesis on the oscillatory frequency of the targeted cortical regions, spTMS can help establish causal links between spontaneous oscillatory activity and perceptual and cognitive functions. Notably, this approach helped to demonstrate that the occipital cortex is periodically involved during specific attentional tasks at the theta (~5 Hz) frequency. We propose that this frequency reflects periodic inter-areal communication for attentional exploration and selection. In the future, clever combination of non-invasive recording and stimulation with well-controlled psychophysics protocols will allow us to further our understanding of the role of brain oscillations for human brain functions.

  4. Perceptual learning and representational learning in humans and animals.

    Science.gov (United States)

    Fiser, József

    2009-05-01

    Traditionally, perceptual learning in humans and classical conditioning in animals have been considered as two very different research areas, with separate problems, paradigms, and explanations. However, a number of themes common to these fields of research emerge when they are approached from the more general concept of representational learning. To demonstrate this, I present results of several learning experiments with human adults and infants, exploring how internal representations of complex unknown visual patterns might emerge in the brain. I provide evidence that this learning cannot be captured fully by any simple pairwise associative learning scheme, but rather by a probabilistic inference process called Bayesian model averaging, in which the brain is assumed to formulate the most likely chunking/grouping of its previous experience into independent representational units. Such a generative model attempts to represent the entire world of stimuli with optimal ability to generalize to likely scenes in the future. I review the evidence showing that a similar philosophy and generative scheme of representation has successfully described a wide range of experimental data in the domain of classical conditioning in animals. These convergent findings suggest that statistical theories of representational learning might help to link human perceptual learning and animal classical conditioning results into a coherent framework.

  5. Unconscious Attentional Capture Effect Can be Induced by Perceptual Learning

    Directory of Open Access Journals (Sweden)

    Zhe Qu

    2011-05-01

    Full Text Available Previous ERP studies have shown that N2pc serves as an index for salient stimuli that capture attention, even if they are task irrelevant. This study aims to investigate whether nonsalient stimuli can capture attention automatically and unconsciously after perceptual learning. Adult subjects were trained with a visual search task for eight to ten sessions. The training task was to detect whether the target (triangle with one particular direction was present or not. After training, an ERP session was performed, in which subjects were required to detect the presence of either the trained triangle (i.e., the target triangle in the training sessions or an untrained triangle. Results showed that, while the untrained triangle did not elicit an N2pc effect, the trained triangle elicited a significant N2pc effect regardless of whether it was perceived correctly or not, even when it was task irrelevant. Moreover, the N2pc effect for the trained triangle was completely retained 3 months later. These results suggest that, after perceptual learning, previously unsalient stimuli become more salient and can capture attention automatically and unconsciously. Once the facilitating process of the unsalient stimulus has been built up in the brain, it can last for a long time.

  6. Task-specific transfer of perceptual learning across sensory modalities.

    Science.gov (United States)

    McGovern, David P; Astle, Andrew T; Clavin, Sarah L; Newell, Fiona N

    2016-01-11

    It is now widely accepted that primary cortical areas of the brain that were once thought to be sensory-specific undergo significant functional reorganisation following sensory deprivation. For instance, loss of vision or audition leads to the brain areas normally associated with these senses being recruited by the remaining sensory modalities [1]. Despite this, little is known about the rules governing crossmodal plasticity in people who experience typical sensory development, or the potential behavioural consequences. Here, we used a novel perceptual learning paradigm to assess whether the benefits associated with training on a task in one sense transfer to another sense. Participants were randomly assigned to a spatial or temporal task that could be performed visually or aurally, which they practiced for five days; before and after training, we measured discrimination thresholds on all four conditions and calculated the extent of transfer between them. Our results show a clear transfer of learning between sensory modalities; however, generalisation was limited to particular conditions. Specifically, learned improvements on the spatial task transferred from the visual domain to the auditory domain, but not vice versa. Conversely, benefits derived from training on the temporal task transferred from the auditory domain to visual domain, but not vice versa. These results suggest a unidirectional transfer of perceptual learning from dominant to non-dominant sensory modalities and place important constraints on models of multisensory processing and plasticity.

  7. Perceptual and neural olfactory similarity in honeybees.

    Directory of Open Access Journals (Sweden)

    Fernando Guerrieri

    2005-04-01

    Full Text Available The question of whether or not neural activity patterns recorded in the olfactory centres of the brain correspond to olfactory perceptual measures remains unanswered. To address this question, we studied olfaction in honeybees Apis mellifera using the olfactory conditioning of the proboscis extension response. We conditioned bees to odours and tested generalisation responses to different odours. Sixteen odours were used, which varied both in their functional group (primary and secondary alcohols, aldehydes and ketones and in their carbon-chain length (from six to nine carbons. The results obtained by presentation of a total of 16 x 16 odour pairs show that (i all odorants presented could be learned, although acquisition was lower for short-chain ketones; (ii generalisation varied depending both on the functional group and the carbon-chain length of odours trained; higher generalisation was found between long-chain than between short-chain molecules and between groups such as primary and secondary alcohols; (iii for some odour pairs, cross-generalisation between odorants was asymmetric; (iv a putative olfactory space could be defined for the honeybee with functional group and carbon-chain length as inner dimensions; (v perceptual distances in such a space correlate well with physiological distances determined from optophysiological recordings of antennal lobe activity. We conclude that functional group and carbon-chain length are inner dimensions of the honeybee olfactory space and that neural activity in the antennal lobe reflects the perceptual quality of odours.

  8. Perceptual and Neural Olfactory Similarity in Honeybees

    Directory of Open Access Journals (Sweden)

    Guerrieri Fernando

    2005-01-01

    Full Text Available The question of whether or not neural activity patterns recorded in the olfactory centres of the brain correspond to olfactory perceptual measures remains unanswered. To address this question, we studied olfaction in honeybees Apis mellifera using the olfactory conditioning of the proboscis extension response. We conditioned bees to odours and tested generalisation responses to different odours. Sixteen odours were used, which varied both in their functional group (primary and secondary alcohols, aldehydes and ketones and in their carbon-chain length (from six to nine carbons.The results obtained by presentation of a total of 16 x 16 odour pairs show that (i all odorants presented could be learned, although acquisition was lower for short-chain ketones; (ii generalisation varied depending both on the functional group and the carbon-chain length of odours trained; higher generalisation was found between long-chain than between short-chain molecules and between groups such as primary and secondary alcohols; (iii for some odour pairs, cross-generalisation between odorants was asymmetric; (iv a putative olfactory space could be defined for the honeybee with functional group and carbon-chain length as inner dimensions; (v perceptual distances in such a space correlate well with physiological distances determined from optophysiological recordings of antennal lobe activity. We conclude that functional group and carbon-chain length are inner dimensions of the honeybee olfactory space and that neural activity in the antennal lobe reflects the perceptual quality of odours.

  9. Perceptual centering effects in body orientation.

    Science.gov (United States)

    Hanes, D A

    2006-04-01

    This study mathematically characterizes the results of DiZio and Lackner (Percept Psychphys 39(1): 39-46) on the perception of self-orientation during circular vection induced by an optokinetic stimulus. Using the hypothesis of perceptual centering, it is shown that five basic centering transformations can logically account for the full range of illusions reported by the subjects. All five of these transformations center the perceived orientations of body components, the rotating disk, and gravity : two align the perceived visual and inertial rotation axes, one centers the perceived axis of visual rotation in front of the head, and two straighten the perceived neck angle. These transformations generate a mathematical semigroup. Application of the semigroup to an actual stimulus condition generates an orbit of predicted illusions. The semigroup analysis of perceptual centering predicts all of the illusions observed in the experiments of DiZio and Lackner (Percept Psychphys 39(1): 39-46). Moreover, the structure of perceptual centering (1) provides a logical explanation for the occurrence of those misperceptions; and (2) predicts the complete set of perceptions that are expected to occur in a larger sample. In addition, our analysis predicts illusions in experimental conditions not yet investigated.

  10. Brightness and darkness as perceptual dimensions.

    Directory of Open Access Journals (Sweden)

    Tony Vladusich

    2007-10-01

    Full Text Available A common-sense assumption concerning visual perception states that brightness and darkness cannot coexist at a given spatial location. One corollary of this assumption is that achromatic colors, or perceived grey shades, are contained in a one-dimensional (1-D space varying from bright to dark. The results of many previous psychophysical studies suggest, by contrast, that achromatic colors are represented as points in a color space composed of two or more perceptual dimensions. The nature of these perceptual dimensions, however, presently remains unclear. Here we provide direct evidence that brightness and darkness form the dimensions of a two-dimensional (2-D achromatic color space. This color space may play a role in the representation of object surfaces viewed against natural backgrounds, which simultaneously induce both brightness and darkness signals. Our 2-D model generalizes to the chromatic dimensions of color perception, indicating that redness and greenness (blueness and yellowness also form perceptual dimensions. Collectively, these findings suggest that human color space is composed of six dimensions, rather than the conventional three.

  11. Perceptual asymmetries and handedness: A neglected link?

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    Daniele eMarzoli

    2014-02-01

    Full Text Available Healthy individuals tend to weigh in more the left than the right side of visual space in a variety of contexts, ranging from pseudoneglect to perceptual asymmetries for faces. Among the common explanations proposed for the attentional and perceptual advantages of the left visual field, a link with the prevalence of right-handedness in humans has never been suggested, although some evidence seems to converge in favor of a bias of spatial attention towards the region most likely coincident with another person’s right hand during a face-to-face interaction. Such a bias might imply an increased efficiency in monitoring both communicative and aggressive acts, the right limb being more used than the left in both types of behaviour. Although attentional and perceptual asymmetries could be linked to right-handedness at the level of phylogeny because of the evolutionarily advantage of directing attention towards the region where others’ dominant hand usually operates, it is also legitimate to question whether, at the ontogenetic level, frequent exposure to right-handed individuals may foster leftward biases. These views are discussed in the light of extant literature, and a number of tests are proposed in order to assess our hypotheses.

  12. Space and time in perceptual causality

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    Benjamin Straube

    2010-04-01

    Full Text Available Inferring causality is a fundamental feature of human cognition that allows us to theorize about and predict future states of the world. Michotte suggested that humans automatically perceive causality based on certain perceptual features of events. However, individual differences in judgments of perceptual causality cast doubt on Michotte’s view. To gain insights in the neural basis of individual difference in the perception of causality, our participants judged causal relationships in animations of a blue ball colliding with a red ball (a launching event while fMRI-data were acquired. Spatial continuity and temporal contiguity were varied parametrically in these stimuli. We did not find consistent brain activation differences between trials judged as caused and those judged as non-caused, making it unlikely that humans have universal instantiation of perceptual causality in the brain. However, participants were slower to respond to and showed greater neural activity for violations of causality, suggesting that humans are biased to expect causal relationships when moving objects appear to interact. Our participants demonstrated considerable individual differences in their sensitivity to spatial and temporal characteristics in perceiving causality. These qualitative differences in sensitivity to time or space in perceiving causality were instantiated in individual differences in activation of the left basal ganglia or right parietal lobe, respectively. Thus, the perception that the movement of one object causes the movement of another is triggered by elemental spatial and temporal sensitivities, which themselves are instantiated in specific distinct neural networks.

  13. Effects of emotional intensity under perceptual load: An event-related potentials (ERPs) study.

    Science.gov (United States)

    Müller-Bardorff, Miriam; Schulz, Claudia; Peterburs, Jutta; Bruchmann, Maximilian; Mothes-Lasch, Martin; Miltner, Wolfgang; Straube, Thomas

    2016-05-01

    Effects of emotional intensity and valence on visual event-related potentials (ERPs) are still poorly understood, in particular in the context of limited attentional resources. In the present EEG study, we investigated the effect of emotional intensity of different emotional facial expressions on P1, N170, early posterior negativity (EPN) and late positive potential (LPP) while varying the amount of available attentional resources. A new stimulus set comprising 90 full color pictures of neutral, happy (low, high intensity), and angry (low, high intensity) expressions was developed. These facial expressions were presented centrally, superimposed by two horizontal bars, and participants engaged in a focal bars task. Availability of attentional resources was varied in two conditions by manipulating the difficulty of the focal bars task (low vs. high perceptual load). Our findings demonstrate intensity and valence effects of task-irrelevant facial expressions on early (N170) and intermediate processing stages (EPN). In addition, task-related effects of perceptual load evolved at intermediate processing stages and were full blown in the time window of LPP. In line with limited resource accounts, valence effects on N170 and EPN were reduced under high perceptual load. Interestingly, apart from this valence by load interaction no further interactions between stimulus and task-driven factors were obtained: Effects of emotional intensity were not modulated by the perceptual load of the focal bars task, indicating that emotional intensity was processed even though attentional resources were heavily restricted. Copyright © 2016. Published by Elsevier B.V.

  14. A perceptual learning deficit in Chinese developmental dyslexia as revealed by visual texture discrimination training.

    Science.gov (United States)

    Wang, Zhengke; Cheng-Lai, Alice; Song, Yan; Cutting, Laurie; Jiang, Yuzheng; Lin, Ou; Meng, Xiangzhi; Zhou, Xiaolin

    2014-08-01

    Learning to read involves discriminating between different written forms and establishing connections with phonology and semantics. This process may be partially built upon visual perceptual learning, during which the ability to process the attributes of visual stimuli progressively improves with practice. The present study investigated to what extent Chinese children with developmental dyslexia have deficits in perceptual learning by using a texture discrimination task, in which participants were asked to discriminate the orientation of target bars. Experiment l demonstrated that, when all of the participants started with the same initial stimulus-to-mask onset asynchrony (SOA) at 300 ms, the threshold SOA, adjusted according to response accuracy for reaching 80% accuracy, did not show a decrement over 5 days of training for children with dyslexia, whereas this threshold SOA steadily decreased over the training for the control group. Experiment 2 used an adaptive procedure to determine the threshold SOA for each participant during training. Results showed that both the group of dyslexia and the control group attained perceptual learning over the sessions in 5 days, although the threshold SOAs were significantly higher for the group of dyslexia than for the control group; moreover, over individual participants, the threshold SOA negatively correlated with their performance in Chinese character recognition. These findings suggest that deficits in visual perceptual processing and learning might, in part, underpin difficulty in reading Chinese.

  15. Cinematic innervation: the intuitive form of perception in the distracted perceptual field

    Directory of Open Access Journals (Sweden)

    Sungyong Ahn

    2013-09-01

    Full Text Available In “The Work of Art in the Age of Its Technological Reproducibility,” Walter Benjamin alluded that the human perceptual field in his time would become more distracted by the intervention of technologies, and so masses’ tactility activated by distraction would be more important in the mechanized perception. Regarding this historical situation, Benjamin anticipated that the new mode of mass perception would be organized through people's collective “innervation” to technologies. This article aims to contextualize this physiological term's cultural, technical, and political implications within various discourses about perception from the late 19th century physiologies to early 20th century film theories. Benjamin considers the tactility of people's potential to reconstruct the optical scheme of perception from the “flatness of screen” in which distances between viewers and perceived objects collapse. In a similar vein, the late 19th century's physiology reconceptualized perception in its relation not so much to the transcendental division of subject/object as to the sensual condition of a retina as “a single immanent plane.” From this perspective, perception is phenomena entailed by a body's contact to a sensual environment, so how sense inputs circulate in a neural network is a determinant for explaining perceptual processes. With regard to this paradigm change, the invention of cinema in the late 19th century was significant because it radically changed the composition of the perceptual field in two directions. Cinema introduced the virtualized perceptual fields on which sense circulations were completely controlled by the operation of camera. At the same time, the mediation of projectors in theaters reorganized viewers’ neural paths for perceptual innervation. As Hugo Münsterberg and Sergei Eisenstein's theories reflect, cinematic media's intervention in the perceptual field made it possible for masses’ collective

  16. Perceptual similarity of visual patterns predicts dynamic neural activation patterns measured with MEG.

    Science.gov (United States)

    Wardle, Susan G; Kriegeskorte, Nikolaus; Grootswagers, Tijl; Khaligh-Razavi, Seyed-Mahdi; Carlson, Thomas A

    2016-05-15

    Perceptual similarity is a cognitive judgment that represents the end-stage of a complex cascade of hierarchical processing throughout visual cortex. Previous studies have shown a correspondence between the similarity of coarse-scale fMRI activation patterns and the perceived similarity of visual stimuli, suggesting that visual objects that appear similar also share similar underlying patterns of neural activation. Here we explore the temporal relationship between the human brain's time-varying representation of visual patterns and behavioral judgments of perceptual similarity. The visual stimuli were abstract patterns constructed from identical perceptual units (oriented Gabor patches) so that each pattern had a unique global form or perceptual 'Gestalt'. The visual stimuli were decodable from evoked neural activation patterns measured with magnetoencephalography (MEG), however, stimuli differed in the similarity of their neural representation as estimated by differences in decodability. Early after stimulus onset (from 50ms), a model based on retinotopic organization predicted the representational similarity of the visual stimuli. Following the peak correlation between the retinotopic model and neural data at 80ms, the neural representations quickly evolved so that retinotopy no longer provided a sufficient account of the brain's time-varying representation of the stimuli. Overall the strongest predictor of the brain's representation was a model based on human judgments of perceptual similarity, which reached the limits of the maximum correlation with the neural data defined by the 'noise ceiling'. Our results show that large-scale brain activation patterns contain a neural signature for the perceptual Gestalt of composite visual features, and demonstrate a strong correspondence between perception and complex patterns of brain activity.

  17. Sex, Symptom, and Premorbid Social Functioning Associated with Perceptual Organization Dysfunction in Schizophrenia

    Directory of Open Access Journals (Sweden)

    Jamie eJoseph

    2013-08-01

    Full Text Available Impairments in visual perceptual organization abilities are a repeatedly observed cognitive deficit in schizophrenia. These impairments have been found to be most prominent among patients with histories of poor premorbid social functioning, disorganized symptoms, and poor clinical outcomes. Despite the demonstration of significant sex differences for these clinical factors in schizophrenia, the extent of sex differences for visual perceptual organization in schizophrenia is unknown. Therefore, we investigated the extent to which previously known correlates (premorbid social sexual functioning and disorganized symptoms and a novel factor (participant sex accounted for performance on two perceptual organization tasks (contour integration and Ebbinghaus illusion that have previously demonstrated sensitivity to schizophrenia. We also determined the relative degree to which each of these factors predicted task scores over and above the others. Schizophrenia patients (N = 109, 43 female from different levels of care were ascertained. Female patients demonstrated higher contour integration scores, but lower performance on the context sensitivity index of the Ebbinghaus illusion, compared to males. Contour integration performance was significantly associated with poorer premorbid adolescent social sexual functioning and higher levels of disorganized symptoms, supporting past results that indicate a relationship among poor premorbid social sexual functioning, disorganized symptoms, and visual perceptual abnormalities in schizophrenia. However, analyses of Ebbinghaus illusion performance suggests there is a complex relationship among patient sex, clinical factors and perceptual abilities with relatively intact bottom-up grouping processes in females, but greater problems, compared to males with more top-down mediated context sensitivity. Therefore, sex differences may be an important consideration for future studies of visual perceptual organization in

  18. Perceptual fluency, auditory generation, and metamemory: analyzing the perceptual fluency hypothesis in the auditory modality.

    Science.gov (United States)

    Besken, Miri; Mulligan, Neil W

    2014-03-01

    Judgments of learning (JOLs) are sometimes influenced by factors that do not impact actual memory performance. One recent proposal is that perceptual fluency during encoding affects metamemory and is a basis of metacognitive illusions. In the present experiments, participants identified aurally presented words that contained inter-spliced silences (the generate condition) or that were intact, a manipulation analogous to visual generation manipulations. The generate condition produced lower perceptual fluency as assessed by both accuracy and identification latency. Consistent with the perceptual fluency hypothesis, the less fluent, generate condition produced lower JOLs than the intact condition. However, actual memory performance was greater in the generation than intact condition in free recall (Experiment 1) and recognition (Experiment 3). The negative effect of generation on JOLs occurred for both aggregate and item-by-item JOLs, but in the latter case, the positive generation effect in actual memory performance was reduced or eliminated (as also occurs with visual generation tasks; Experiments 2 and 4). Furthermore, the decrease in perceptual fluency produced by the generation manipulation was correlated with the decrease in JOLs for this condition (Experiment 5). The negative effect of generation on JOLs persisted even when participants were warned that the generation condition produces equal or greater memory performance compared to the intact condition (Experiment 6). The results are in accord with the perceptual fluency hypothesis and show that this metamemory illusion is related to objective measures of perceptual difficulty. With regard to actual memory performance, this novel auditory generation manipulation produces results consistent with those produced in the visual modality.

  19. The role of answer fluency and perceptual fluency as metacognitive cues for initiating analytic thinking.

    Science.gov (United States)

    Thompson, Valerie A; Turner, Jamie A Prowse; Pennycook, Gordon; Ball, Linden J; Brack, Hannah; Ophir, Yael; Ackerman, Rakefet

    2013-08-01

    Although widely studied in other domains, relatively little is known about the metacognitive processes that monitor and control behaviour during reasoning and decision-making. In this paper, we examined the conditions under which two fluency cues are used to monitor initial reasoning: answer fluency, or the speed with which the initial, intuitive answer is produced (Thompson, Prowse Turner, & Pennycook, 2011), and perceptual fluency, or the ease with which problems can be read (Alter, Oppenheimer, Epley, & Eyre, 2007). The first two experiments demonstrated that answer fluency reliably predicted Feeling of Rightness (FOR) judgments to conditional inferences and base rate problems, which subsequently predicted the amount of deliberate processing as measured by thinking time and answer changes; answer fluency also predicted retrospective confidence judgments (Experiment 3b). Moreover, the effect of answer fluency on reasoning was independent from the effect of perceptual fluency, establishing that these are empirically independent constructs. In five experiments with a variety of reasoning problems similar to those of Alter et al. (2007), we found no effect of perceptual fluency on FOR, retrospective confidence or accuracy; however, we did observe that participants spent more time thinking about hard to read stimuli, although this additional time did not result in answer changes. In our final two experiments, we found that perceptual disfluency increased accuracy on the CRT (Frederick, 2005), but only amongst participants of high cognitive ability. As Alter et al.'s samples were gathered from prestigious universities, collectively, the data to this point suggest that perceptual fluency prompts additional processing in general, but this processing may results in higher accuracy only for the most cognitively able. Crown Copyright © 2012. Published by Elsevier B.V. All rights reserved.

  20. Infant perceptual development for faces and spoken words: an integrated approach.

    Science.gov (United States)

    Watson, Tamara L; Robbins, Rachel A; Best, Catherine T

    2014-11-01

    There are obvious differences between recognizing faces and recognizing spoken words or phonemes that might suggest development of each capability requires different skills. Recognizing faces and perceiving spoken language, however, are in key senses extremely similar endeavors. Both perceptual processes are based on richly variable, yet highly structured input from which the perceiver needs to extract categorically meaningful information. This similarity could be reflected in the perceptual narrowing that occurs within the first year of life in both domains. We take the position that the perceptual and neurocognitive processes by which face and speech recognition develop are based on a set of common principles. One common principle is the importance of systematic variability in the input as a source of information rather than noise. Experience of this variability leads to perceptual tuning to the critical properties that define individual faces or spoken words versus their membership in larger groupings of people and their language communities. We argue that parallels can be drawn directly between the principles responsible for the development of face and spoken language perception.

  1. Clinical characteristics of patients with persistent postural-perceptual dizziness

    OpenAIRE

    Roseli Saraiva Moreira Bittar; Eliane Maria Dias von Söhsten Lins

    2015-01-01

    INTRODUCTION: Persistent postural-perceptual dizziness is the dizziness that lasts for over three months with no clinical explanation for its persistence. The patient's motor response pattern presents changes and most patients manifest significant anxiety. OBJECTIVE: To evaluate the clinical characteristics of patients with persistent postural and perceptual dizziness. METHODS: statistical analysis of clinical aspects of patients with persistent postural-perceptual dizziness. RESULTS: 81 pati...

  2. The role of perceptual load in object recognition

    OpenAIRE

    Lavie, Nilli; Lin, Zhicheng; Zokaei, Nahid; Thoma, Volker

    2009-01-01

    Predictions from perceptual load theory (Lavie, 1995, 2005) regarding object recognition across the same or different viewpoints were tested. Results showed that high perceptual load reduces distracter\\ud recognition levels despite always presenting distracter objects from the same view. They also showed that the levels of distracter recognition were unaffected by a change in the distracter object view under conditions of low perceptual load. These results were found both with repetition prim...

  3. Time-resolved neuroimaging of visual short term memory consolidation by post-perceptual attention shifts.

    Science.gov (United States)

    Hecht, Marcus; Thiemann, Ulf; Freitag, Christine M; Bender, Stephan

    2016-01-15

    Post-perceptual cues can enhance visual short term memory encoding even after the offset of the visual stimulus. However, both the mechanisms by which the sensory stimulus characteristics are buffered as well as the mechanisms by which post-perceptual selective attention enhances short term memory encoding remain unclear. We analyzed late post-perceptual event-related potentials (ERPs) in visual change detection tasks (100ms stimulus duration) by high-resolution ERP analysis to elucidate these mechanisms. The effects of early and late auditory post-cues (300ms or 850ms after visual stimulus onset) as well as the effects of a visual interference stimulus were examined in 27 healthy right-handed adults. Focusing attention with post-perceptual cues at both latencies significantly improved memory performance, i.e. sensory stimulus characteristics were available for up to 850ms after stimulus presentation. Passive watching of the visual stimuli without auditory cue presentation evoked a slow negative wave (N700) over occipito-temporal visual areas. N700 was strongly reduced by a visual interference stimulus which impeded memory maintenance. In contrast, contralateral delay activity (CDA) still developed in this condition after the application of auditory post-cues and was thereby dissociated from N700. CDA and N700 seem to represent two different processes involved in short term memory encoding. While N700 could reflect visual post processing by automatic attention attraction, CDA may reflect the top-down process of searching selectively for the required information through post-perceptual attention. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Conceptual and Methodological Concerns in the Theory of Perceptual Load

    Directory of Open Access Journals (Sweden)

    Hanna eBenoni

    2013-08-01

    Full Text Available The present paper provides a short critical review of the theory of perceptual load. It closely examines the basic tenets and assumptions of the theory and identifies major conceptual and methodological problems that have been largely ignored in the literature. The discussion focuses on problems in the definition of the concept of perceptual load, on the circularity in the characterization and manipulation of perceptual load and the confusion between the concept of perceptual load and its operationalization. The paper also selectively reviews evidence supporting the theory as well as inconsistent evidence which proposed alternative dominant factors influencing the efficacy of attentional selection.

  5. Perceptual dehumanization of faces is activated by norm violations and facilitates norm enforcement.

    Science.gov (United States)

    Fincher, Katrina M; Tetlock, Philip E

    2016-02-01

    This article uses methods drawn from perceptual psychology to answer a basic social psychological question: Do people process the faces of norm violators differently from those of others--and, if so, what is the functional significance? Seven studies suggest that people process these faces different and the differential processing makes it easier to punish norm violators. Studies 1 and 2 use a recognition-recall paradigm that manipulated facial-inversion and spatial frequency to show that people rely upon face-typical processing less when they perceive norm violators' faces. Study 3 uses a facial composite task to demonstrate that the effect is actor dependent, not action dependent, and to suggest that configural processing is the mechanism of perceptual change. Studies 4 and 5 use offset faces to show that configural processing is only attenuated when they belong to perpetrators who are culpable. Studies 6 and 7 show that people find it easier to punish inverted faces and harder to punish faces displayed in low spatial frequency. Taken together, these data suggest a bidirectional flow of causality between lower-order perceptual and higher-order cognitive processes in norm enforcement.

  6. Where have we gone wrong? Perceptual load does not affect selective attention.

    Science.gov (United States)

    Benoni, Hanna; Tsal, Yehoshua

    2010-06-18

    The theory of perceptual load (Lavie & Tsal, 1994) proposes that with low load in relevant processing left over resources spill over to process irrelevant distractors. Interference could only be prevented under High-Load Conditions where relevant processing exhausts attentional resources. The theory is based primarily on the finding that distractor interference obtained in low load displays, when the target appears alone, is eliminated in high load displays when it is embedded among neutral letters. However, a possible alternative interpretation of this effect is that the distractor is similarly processed in both displays, yet its interference in the large displays is diluted by the presence of the neutral letters. We separated the possible effects of load and dilution by adding dilution displays that were high in dilution and low in perceptual load. In the first experiment these displays contained as many letters as the high load displays, but their neutral letters were clearly distinguished from the target, thereby allowing for a low load processing mode. In the second experiment we presented identical multicolor displays in the Dilution and High-Load Conditions. However, in the former the target color was known in advance (thereby preserving a low load processing mode) whereas in the latter it was not. In both experiments distractor interference was completely eliminated under the Dilution Condition. Thus, it is dilution not perceptual load affecting distractor processing.

  7. False Memories Lack Perceptual Detail: Evidence from Implicit Word-Stem Completion and Perceptual Identification Tests

    Science.gov (United States)

    Hicks, J.L.; Starns, J.J.

    2005-01-01

    We used implicit measures of memory to ascertain whether false memories for critical nonpresented items in the DRM paradigm (Deese, 1959; Roediger & McDermott, 1995) contain structural and perceptual detail. In Experiment 1, we manipulated presentation modality in a visual word-stem-completion task. Critical item priming was significant and…

  8. A ratio model of perceptual transparency.

    Science.gov (United States)

    Tommasi, M

    1999-12-01

    A ratio model of the achromatic transparency of a phenomenal surface on a bipartite background is proposed. The model asserts that transparency corresponds to the evaluation of the ratio of the lightness difference inside the transparent surface to the difference in reference lightness inside the background. It applies to both balanced and unbalanced transparency. The ratio model was compared experimentally with the previous perceptual model of achromatic transparency proposed by Metelli. Each model was tested by comparing the rated with the predicted transparency. Analysis shows that the ratio model provides better predictions of transparency than those provided by Metelli's model.

  9. Perceptual Grouping via Untangling Gestalt Principles

    DEFF Research Database (Denmark)

    Qi, Yonggang; Guo, Jun; Li, Yi

    2013-01-01

    Gestalt principles, a set of conjoining rules derived from hu- man visual studies, have been known to play an important role in computer vision. Many applications such as image segmentation, contour grouping and scene understanding of- ten rely on such rules to work. However, the problem of Gestalt...... the importance of Gestalt rules by solving a learning to rank problem, and formulate a multi-label graph-cuts algo- rithm to group image primitives while taking into account the learned Gestalt confliction. Our experiment results confirm the existence of Gestalt confliction in perceptual grouping and demonstrate...

  10. Perceptual Grouping via Untangling Gestalt Principles

    DEFF Research Database (Denmark)

    Qi, Yonggang; Guo, Jun; Li, Yi

    2013-01-01

    Gestalt principles, a set of conjoining rules derived from hu- man visual studies, have been known to play an important role in computer vision. Many applications such as image segmentation, contour grouping and scene understanding of- ten rely on such rules to work. However, the problem of Gestalt...... the importance of Gestalt rules by solving a learning to rank problem, and formulate a multi-label graph-cuts algo- rithm to group image primitives while taking into account the learned Gestalt confliction. Our experiment results confirm the existence of Gestalt confliction in perceptual grouping and demonstrate...

  11. Perceptual and motor attribute ratings for 559 object concepts.

    Science.gov (United States)

    Amsel, Ben D; Urbach, Thomas P; Kutas, Marta

    2012-12-01

    To understand how and when object knowledge influences the neural underpinnings of language comprehension and linguistic behavior, it is critical to determine the specific kinds of knowledge that people have. To extend the normative data currently available, we report a relatively more comprehensive set of object attribute rating norms for 559 concrete object nouns, each rated on seven attributes corresponding to sensory and motor modalities-color, motion, sound, smell, taste, graspability, and pain-in addition to familiarity (376 raters, M = 23 raters per item). The mean ratings were subjected to principal-components analysis, revealing two primary dimensions plausibly interpreted as relating to survival. We demonstrate the utility of these ratings in accounting for lexical and semantic decision latencies. These ratings should prove useful for the design and interpretation of experimental tests of conceptual and perceptual object processing.

  12. Perceptual-motor learning benefits from increased stress and anxiety.

    Science.gov (United States)

    Hordacre, Brenton; Immink, Maarten A; Ridding, Michael C; Hillier, Susan

    2016-10-01

    The purpose of this study was to manipulate psychological stress and anxiety to investigate effects on ensuing perceptual-motor learning. Thirty-six participants attended two experimental sessions separated by 24h. In the first session, participants were randomized to either a mental arithmetic task known to increase stress and anxiety levels or a control condition and subsequently completed training on a speeded precision pinch task. Learning of the pinch task was assessed at the second session. Those exposed to the high stress-anxiety mental arithmetic task prior to training reported elevated levels of both stress and anxiety and demonstrated shorter movement times and improved retention of movement accuracy and movement variability. Response execution processes appear to benefit from elevated states of stress and anxiety immediately prior to training even when elicited by an unrelated task.

  13. Dissociation between conceptual and perceptual implicit memory:Evidence from patients with frontal and occipital lobe lesions

    Directory of Open Access Journals (Sweden)

    Liang eGong

    2016-01-01

    Full Text Available The latest neuroimaging studies about implicit memory have revealed that different implicit memory types may be processed by different parts of the brain. However, studies have rarely examined what subtypes of implicit memory processes are affected in patients with various brain-injuries. Twenty patients with frontal lobe injury, 25 patients with occipital lobe injury, and 29 healthy controls were recruited for the study. Two subtypes of implicit memory were investigated by using structurally parallel perceptual (picture identification task and conceptual (category exemplar generation task implicit memory tests in the three groups, as well as explicit memory tests. The results indicated that the priming of conceptual implicit memory and explicit memory tasks in patients with frontal lobe injury was poorer than that observed in healthy controls, while perceptual implicit memory was identical between the two groups. In contrast, the priming of perceptual implicit memory in patients with occipital lobe injury was poorer than that in healthy controls, while the priming of conceptual implicit memory and explicit memory was similar to that in healthy controls. This double dissociation between perceptual and conceptual implicit memory across the brain areas implies that occipital lobes may participate in perceptual implicit memory, while frontal lobes may be involved in processing conceptual memory.

  14. Applying perceptual and adaptive learning techniques for teaching introductory histopathology

    Directory of Open Access Journals (Sweden)

    Sally Krasne

    2013-01-01

    Full Text Available Background: Medical students are expected to master the ability to interpret histopathologic images, a difficult and time-consuming process. A major problem is the issue of transferring information learned from one example of a particular pathology to a new example. Recent advances in cognitive science have identified new approaches to address this problem. Methods: We adapted a new approach for enhancing pattern recognition of basic pathologic processes in skin histopathology images that utilizes perceptual learning techniques, allowing learners to see relevant structure in novel cases along with adaptive learning algorithms that space and sequence different categories (e.g. diagnoses that appear during a learning session based on each learner′s accuracy and response time (RT. We developed a perceptual and adaptive learning module (PALM that utilized 261 unique images of cell injury, inflammation, neoplasia, or normal histology at low and high magnification. Accuracy and RT were tracked and integrated into a "Score" that reflected students rapid recognition of the pathologies and pre- and post-tests were given to assess the effectiveness. Results: Accuracy, RT and Scores significantly improved from the pre- to post-test with Scores showing much greater improvement than accuracy alone. Delayed post-tests with previously unseen cases, given after 6-7 weeks, showed a decline in accuracy relative to the post-test for 1 st -year students, but not significantly so for 2 nd -year students. However, the delayed post-test scores maintained a significant and large improvement relative to those of the pre-test for both 1 st and 2 nd year students suggesting good retention of pattern recognition. Student evaluations were very favorable. Conclusion: A web-based learning module based on the principles of cognitive science showed an evidence for improved recognition of histopathology patterns by medical students.

  15. Perceptual Drawing as a Learning Tool in a College Biology Laboratory

    Science.gov (United States)

    Landin, Jennifer

    2011-12-01

    The use of drawing in the classroom has a contentious history in the U.S. education system. While most instructors and students agree that the activity helps students focus and observe more details, there is a lack of empirical data to support these positions. This study examines the use of three treatments (writing a description, drawing a perceptual image, or drawing a perceptual image after participating in a short instructional lesson on perceptual drawing) each week over the course of a semester. The students in the "Drawing with Instruction" group exhibit a small but significantly higher level of content knowledge by the end of the semester. When comparing Attitude Toward Biology and Observational Skills among the three groups, inconclusive results restrict making any conclusions. Student perceptions of the task are positive, although not as strong as indicated by other studies. A student behavior observed during the first study led to another question regarding student cognitive processes, and demonstrated cognitive change in student-rendered drawings. The data from the second study indicate that hemispheric dominance or visual/verbal learning do not impact learning from perceptual drawing activities. However, conservatism and need for closure are inversely proportional to the change seen in student drawings over the course of a lesson. Further research is needed to verify these conclusions, as the second study has a small number of participants.

  16. Functional consequences of experience-dependent plasticity on tactile perception following perceptual learning.

    Science.gov (United States)

    Trzcinski, Natalie K; Gomez-Ramirez, Manuel; Hsiao, Steven S

    2016-09-01

    Continuous training enhances perceptual discrimination and promotes neural changes in areas encoding the experienced stimuli. This type of experience-dependent plasticity has been demonstrated in several sensory and motor systems. Particularly, non-human primates trained to detect consecutive tactile bar indentations across multiple digits showed expanded excitatory receptive fields (RFs) in somatosensory cortex. However, the perceptual implications of these anatomical changes remain undetermined. Here, we trained human participants for 9 days on a tactile task that promoted expansion of multi-digit RFs. Participants were required to detect consecutive indentations of bar stimuli spanning multiple digits. Throughout the training regime we tracked participants' discrimination thresholds on spatial (grating orientation) and temporal tasks on the trained and untrained hands in separate sessions. We hypothesized that training on the multi-digit task would decrease perceptual thresholds on tasks that require stimulus processing across multiple digits, while also increasing thresholds on tasks requiring discrimination on single digits. We observed an increase in orientation thresholds on a single digit. Importantly, this effect was selective for the stimulus orientation and hand used during multi-digit training. We also found that temporal acuity between digits improved across trained digits, suggesting that discriminating the temporal order of multi-digit stimuli can transfer to temporal discrimination of other tactile stimuli. These results suggest that experience-dependent plasticity following perceptual learning improves and interferes with tactile abilities in manners predictive of the task and stimulus features used during training.

  17. Perceptual pitch deficits coexist with pitch production difficulties in music but not Mandarin speech.

    Science.gov (United States)

    Yang, Wu-Xia; Feng, Jie; Huang, Wan-Ting; Zhang, Cheng-Xiang; Nan, Yun

    2013-01-01

    Congenital amusia is a musical disorder that mainly affects pitch perception. Among Mandarin speakers, some amusics also have difficulties in processing lexical tones (tone agnosics). To examine to what extent these perceptual deficits may be related to pitch production impairments in music and Mandarin speech, eight amusics, eight tone agnosics, and 12 age- and IQ-matched normal native Mandarin speakers were asked to imitate music note sequences and Mandarin words of comparable lengths. The results indicated that both the amusics and tone agnosics underperformed the controls on musical pitch production. However, tone agnosics performed no worse than the amusics, suggesting that lexical tone perception deficits may not aggravate musical pitch production difficulties. Moreover, these three groups were all able to imitate lexical tones with perfect intelligibility. Taken together, the current study shows that perceptual musical pitch and lexical tone deficits might coexist with musical pitch production difficulties. But at the same time these perceptual pitch deficits might not affect lexical tone production or the intelligibility of the speech words that were produced. The perception-production relationship for pitch among individuals with perceptual pitch deficits may be, therefore, domain-dependent.

  18. Perceptual pitch deficits coexist with pitch production difficulties in music but not Mandarin speech

    Science.gov (United States)

    Yang, Wu-xia; Feng, Jie; Huang, Wan-ting; Zhang, Cheng-xiang; Nan, Yun

    2014-01-01

    Congenital amusia is a musical disorder that mainly affects pitch perception. Among Mandarin speakers, some amusics also have difficulties in processing lexical tones (tone agnosics). To examine to what extent these perceptual deficits may be related to pitch production impairments in music and Mandarin speech, eight amusics, eight tone agnosics, and 12 age- and IQ-matched normal native Mandarin speakers were asked to imitate music note sequences and Mandarin words of comparable lengths. The results indicated that both the amusics and tone agnosics underperformed the controls on musical pitch production. However, tone agnosics performed no worse than the amusics, suggesting that lexical tone perception deficits may not aggravate musical pitch production difficulties. Moreover, these three groups were all able to imitate lexical tones with perfect intelligibility. Taken together, the current study shows that perceptual musical pitch and lexical tone deficits might coexist with musical pitch production difficulties. But at the same time these perceptual pitch deficits might not affect lexical tone production or the intelligibility of the speech words that were produced. The perception-production relationship for pitch among individuals with perceptual pitch deficits may be, therefore, domain-dependent. PMID:24474944

  19. Functional consequences of experience-dependent plasticity on tactile perception following perceptual learning

    Science.gov (United States)

    Trzcinski, Natalie K; Gomez-Ramirez, Manuel; Hsiao, Steven S.

    2016-01-01

    Continuous training enhances perceptual discrimination and promotes neural changes in areas encoding the experienced stimuli. This type of experience-dependent plasticity has been demonstrated in several sensory and motor systems. Particularly, non-human primates trained to detect consecutive tactile bar indentations across multiple digits showed expanded excitatory receptive fields (RFs) in somatosensory cortex. However, the perceptual implications of these anatomical changes remain undetermined. Here, we trained human participants for nine days on a tactile task that promoted expansion of multi-digit RFs. Participants were required to detect consecutive indentations of bar stimuli spanning multiple digits. Throughout the training regime we tracked participants’ discrimination thresholds on spatial (grating orientation) and temporal tasks on the trained and untrained hands in separate sessions. We hypothesized that training on the multi-digit task would decrease perceptual thresholds on tasks that require stimulus processing across multiple digits, while also increasing thresholds on tasks requiring discrimination on single digits. We observed an increase in orientation thresholds on a single-digit. Importantly, this effect was selective for the stimulus orientation and hand used during multi-digit training. We also found that temporal acuity between digits improved across trained digits, suggesting that discriminating the temporal order of multi-digit stimuli can transfer to temporal discrimination of other tactile stimuli. These results suggest that experience-dependent plasticity following perceptual learning improves and interferes with tactile abilities in manners predictive of the task and stimulus features used during training. PMID:27422224

  20. Do you see what we see? The complex effects of perceptual distance between leaders and teams.

    Science.gov (United States)

    Gibson, Cristina B; Cooper, Cecily D; Conger, Jay A

    2009-01-01

    Previous distance-related theories and concepts (e.g., social distance) have failed to address the sometimes wide disparity in perceptions between leaders and the teams they lead. Drawing from the extensive literature on teams, leadership, and cognitive models of social information processing, the authors develop the concept of leader-team perceptual distance, defined as differences between a leader and a team in perceptions of the same social stimulus. The authors investigate the effects of perceptual distance on team performance, operationalizing the construct with 3 distinct foci: goal accomplishment, constructive conflict, and decision-making autonomy. Analyzing leader, member, and customer survey responses for a large sample of teams, the authors demonstrate that perceptual distance between a leader and a team regarding goal accomplishment and constructive conflict have a nonlinear relationship with team performance. Greater perceptual differences are associated with decreases in team performance. Moreover, this effect is strongest when a team's perceptions are more positive than the leader's are (as opposed to the reverse). This pattern illustrates the pervasive effects that perceptions can have on team performance, highlighting the importance of developing awareness of perceptions in order to increase effectiveness. Implications for theory and practice are delineated. (PsycINFO Database Record (c) 2009 APA, all rights reserved).

  1. Perceptual Pitch Deficits Coexist with Pitch Production Difficulties in Music but Not Mandarin Speech

    Directory of Open Access Journals (Sweden)

    Wu-xia eYang

    2014-01-01

    Full Text Available Congenital amusia is a musical disorder that mainly affects pitch perception. Among Mandarin speakers, some amusics also have difficulties in processing lexical tones (tone agnosics. To examine to what extent these perceptual deficits may be related to pitch production impairments in music and Mandarin speech, 8 amusics, 8 tone agnosics, and 12 age- and IQ-matched normal native Mandarin speakers were asked to imitate music note sequences and Mandarin words of comparable lengths. The results indicated that both the amusics and tone agnosics underperformed the controls on musical pitch production. However, tone agnosics performed no worse than the amusics, suggesting that lexical tone perception deficits may not aggravate musical pitch production difficulties. Moreover, these three groups were all able to imitate lexical tones with perfect intelligibility. Taken together, the current study shows that perceptual musical pitch and lexical tone deficits might coexist with musical pitch production difficulties. But at the same time these perceptual pitch deficits might not affect lexical tone production or the intelligibility of the speech words that were produced. The perception-production relationship for pitch among individuals with perceptual pitch deficits may be, therefore, domain-dependent.

  2. The fate of task-irrelevant visual motion: perceptual load versus feature-based attention.

    Science.gov (United States)

    Taya, Shuichiro; Adams, Wendy J; Graf, Erich W; Lavie, Nilli

    2009-11-18

    We tested contrasting predictions derived from perceptual load theory and from recent feature-based selection accounts. Observers viewed moving, colored stimuli and performed low or high load tasks associated with one stimulus feature, either color or motion. The resultant motion aftereffect (MAE) was used to evaluate attentional allocation. We found that task-irrelevant visual features received less attention than co-localized task-relevant features of the same objects. Moreover, when color and motion features were co-localized yet perceived to belong to two distinct surfaces, feature-based selection was further increased at the expense of object-based co-selection. Load theory predicts that the MAE for task-irrelevant motion would be reduced with a higher load color task. However, this was not seen for co-localized features; perceptual load only modulated the MAE for task-irrelevant motion when this was spatially separated from the attended color location. Our results suggest that perceptual load effects are mediated by spatial selection and do not generalize to the feature domain. Feature-based selection operates to suppress processing of task-irrelevant, co-localized features, irrespective of perceptual load.

  3. Perceptual separability of featural and configural information in congenital prosopagnosia.

    Science.gov (United States)

    Kimchi, Ruth; Behrmann, Marlene; Avidan, Galia; Amishav, Rama

    2012-01-01

    The deficit in face recognition in individuals with prosopagnosia has often been attributed to an underlying impairment in holistic processing. Exactly what constitutes holistic processing has remained controversial, however. Here, we compare how configural information and featural information interact during face processing in a group of individuals with congenital prosopagnosia (CP) and matched controls. We adopted Amishav and Kimchi's version of Garner's speeded classification task, in which observers classify upright faces based on configural (intereyes and nose-mouth spacing) or featural (shape of eyes, nose, and mouth) information while the other dimension remains constant or varied randomly. We replicated the finding that normal observers evince symmetric Garner interference--failure to selectively attend to features without being influenced by irrelevant variation in configuration, and vice versa--indicating that featural and configural information are integral in normal face processing. In contrast, the CPs showed no Garner interference: They were able to attend to configural information without interference from irrelevant variation in featural information, and they were able to attend to featural information without interference from irrelevant variation in configural information. The absence of Garner interference in CP provides strong evidence that featural information and configural information are perceptually separable in CP's face processing. These findings indicate that CPs do not perceive faces holistically; rather, they process featural and configural information independently.

  4. Implicit Recognition Based on Lateralized Perceptual Fluency

    Directory of Open Access Journals (Sweden)

    Iliana M. Vargas

    2012-02-01

    Full Text Available In some circumstances, accurate recognition of repeated images in an explicit memory test is driven by implicit memory. We propose that this “implicit recognition” results from perceptual fluency that influences responding without awareness of memory retrieval. Here we examined whether recognition would vary if images appeared in the same or different visual hemifield during learning and testing. Kaleidoscope images were briefly presented left or right of fixation during divided-attention encoding. Presentation in the same visual hemifield at test produced higher recognition accuracy than presentation in the opposite visual hemifield, but only for guess responses. These correct guesses likely reflect a contribution from implicit recognition, given that when the stimulated visual hemifield was the same at study and test, recognition accuracy was higher for guess responses than for responses with any level of confidence. The dramatic difference in guessing accuracy as a function of lateralized perceptual overlap between study and test suggests that implicit recognition arises from memory storage in visual cortical networks that mediate repetition-induced fluency increments.

  5. What is automatized during perceptual categorization?

    Science.gov (United States)

    Roeder, Jessica L; Ashby, F Gregory

    2016-09-01

    An experiment is described that tested whether stimulus-response associations or an abstract rule are automatized during extensive practice at perceptual categorization. Twenty-seven participants each completed 12,300 trials of perceptual categorization, either on rule-based (RB) categories that could be learned explicitly or information-integration (II) categories that required procedural learning. Each participant practiced predominantly on a primary category structure, but every third session they switched to a secondary structure that used the same stimuli and responses. Half the stimuli retained their same response on the primary and secondary categories (the congruent stimuli) and half switched responses (the incongruent stimuli). Several results stood out. First, performance on the primary categories met the standard criteria of automaticity by the end of training. Second, for the primary categories in the RB condition, accuracy and response time (RT) were identical on congruent and incongruent stimuli. In contrast, for the primary II categories, accuracy was higher and RT was lower for congruent than for incongruent stimuli. These results are consistent with the hypothesis that rules are automatized in RB tasks, whereas stimulus-response associations are automatized in II tasks. A cognitive neuroscience theory is proposed that accounts for these results.

  6. Perceptual organization at attended and unattended locations

    Institute of Scientific and Technical Information of China (English)

    HAN; Shihui; Glyn; W.; Humphreys

    2005-01-01

    This study examined the effects of attention on forming perceptual units by proximity grouping and by uniform connectedness (UC). In Experiment 1 a row of three global letters defined by either proximity or UC was presented at the center of the visual field. Participants were asked to identify the letter in the middle of stimulus arrays while ignoring the flankers. The stimulus onset asynchrony (SOA) between stimulus arrays and masks varied between 180 and 500 ms. We found that responses to targets defined by proximity grouping were slower than to those defined by UC at median SOAs but there were no differences at short or long SOAs. Incongruent flankers slowed responses to targets and this flanker compatibility effect was larger for UC than for proximity-defined flankers. Experiment 2 examined the effects of spatial precueing on discrimination responses to proximity- and UC-defined targets. The advantage for targets defined by UC over targets defined by proximity grouping was greater at uncued relative to cued locations. The results suggest that the advantage for UC over proximity grouping in forming perceptual units is contingent on the stimuli not being fully attended, and that paying attention to the stimuli differentially benefits proximity grouping.

  7. Implicit recognition based on lateralized perceptual fluency.

    Science.gov (United States)

    Vargas, Iliana M; Voss, Joel L; Paller, Ken A

    2012-02-06

    In some circumstances, accurate recognition of repeated images in an explicit memory test is driven by implicit memory. We propose that this "implicit recognition" results from perceptual fluency that influences responding without awareness of memory retrieval. Here we examined whether recognition would vary if images appeared in the same or different visual hemifield during learning and testing. Kaleidoscope images were briefly presented left or right of fixation during divided-attention encoding. Presentation in the same visual hemifield at test produced higher recognition accuracy than presentation in the opposite visual hemifield, but only for guess responses. These correct guesses likely reflect a contribution from implicit recognition, given that when the stimulated visual hemifield was the same at study and test, recognition accuracy was higher for guess responses than for responses with any level of confidence. The dramatic difference in guessing accuracy as a function of lateralized perceptual overlap between study and test suggests that implicit recognition arises from memory storage in visual cortical networks that mediate repetition-induced fluency increments.

  8. On the filter approach to perceptual transparency.

    Science.gov (United States)

    Faul, Franz; Ekroll, Vebjørn

    2011-06-09

    In F. Faul and V. Ekroll (2002), we proposed a filter model of perceptual transparency that describes typical color changes caused by optical filters and accurately predicts perceived transparency. Here, we provide a more elaborate analysis of this model: (A) We address the question of how the model parameters can be estimated in a robust way. (B) We show that the parameters of the original model, which are closely related to physical properties, can be transformed into the alternative parameters hue H, saturation S, transmittance V, and clarity C that better reflect perceptual dimensions of perceived transparency. (C) We investigate the relation of H, S, V, and C to the physical parameters of optical filters and show that C is closely related to the refractive index of the filter, whereas V and S are closely related to its thickness. We also demonstrate that the latter relationship can be used to estimate relative filter thickness from S and V. (D) We investigate restrictions on S that result from properties of color space and determine its distribution under realistic choices of physical parameters. (E) We experimentally determine iso-saturation curves that yield nominal saturation values for filters of different hue such that they appear equally saturated.

  9. Facial expression recognition in perceptual color space.

    Science.gov (United States)

    Lajevardi, Seyed Mehdi; Wu, Hong Ren

    2012-08-01

    This paper introduces a tensor perceptual color framework (TPCF) for facial expression recognition (FER), which is based on information contained in color facial images. The TPCF enables multi-linear image analysis in different color spaces and demonstrates that color components provide additional information for robust FER. Using this framework, the components (in either RGB, YCbCr, CIELab or CIELuv space) of color images are unfolded to two-dimensional (2- D) tensors based on multi-linear algebra and tensor concepts, from which the features are extracted by Log-Gabor filters. The mutual information quotient (MIQ) method is employed for feature selection. These features are classified using a multi-class linear discriminant analysis (LDA) classifier. The effectiveness of color information on FER using low-resolution and facial expression images with illumination variations is assessed for performance evaluation. Experimental results demonstrate that color information has significant potential to improve emotion recognition performance due to the complementary characteristics of image textures. Furthermore, the perceptual color spaces (CIELab and CIELuv) are better overall for facial expression recognition than other color spaces by providing more efficient and robust performance for facial expression recognition using facial images with illumination variation.

  10. Revisiting the empirical case against perceptual modularity

    Science.gov (United States)

    Masrour, Farid; Nirshberg, Gregory; Schon, Michael; Leardi, Jason; Barrett, Emily

    2015-01-01

    Some theorists hold that the human perceptual system has a component that receives input only from units lower in the perceptual hierarchy. This thesis, that we shall here refer to as the encapsulation thesis, has been at the center of a continuing debate for the past few decades. Those who deny the encapsulation thesis often rely on the large body of psychological findings that allegedly suggest that perception is influenced by factors such as the beliefs, desires, goals, and the expectations of the perceiver. Proponents of the encapsulation thesis, however, often argue that, when correctly interpreted, these psychological findings are compatible with the thesis. In our view, the debate over the significance and the correct interpretation of these psychological findings has reached an impasse. We hold that this impasse is due to the methodological limitations over psychophysical experiments, and it is very unlikely that such experiments, on their own, could yield results that would settle the debate. After defending this claim, we argue that integrating data from cognitive neuroscience resolves the debate in favor of those who deny the encapsulation thesis. PMID:26583001

  11. Dysarthria in Friedreich's ataxia: a perceptual analysis.

    Science.gov (United States)

    Folker, Joanne; Murdoch, Bruce; Cahill, Louise; Delatycki, Martin; Corben, Louise; Vogel, Adam

    2010-01-01

    The aims of this study were to: (1) evaluate the perceptual speech dimensions, speech intelligibility and dysarthria severity of a group of individuals diagnosed with Friedreich's ataxia (FRDA); (2) determine the presence of subgroups within FRDA dysarthria; (3) investigate the relationship between the speech outcome and the clinical factors of disease progression. The study included 38 individuals (21 female, 17 male) with a confirmed diagnosis of FRDA. A group of 20 non-neurologically impaired individuals served as controls. Perceptual analysis, investigating 30 different dimensions of speech, was conducted on a speech sample obtained from each participant. In addition, the Assessment of Intelligibility of Dysarthria Speech was administered. All FRDA participants presented with dysarthria with severities ranging from mild to moderate. Cluster analysis revealed 3 subgroups, the first presenting with mild dysarthric symptoms, the second with increased velopharyngeal involvement and the third characterized by increased laryngeal dysfunction. Dysarthria severity showed a significant correlation to disease duration but to no other clinical measure. The findings support the notion of subgroups in FRDA dysarthria, representing distinct impairments of the speech mechanism and perhaps reflective of differing evolutions beyond the cerebellum.

  12. The incidental binding of color and shape is insensitive to the perceptual load

    Directory of Open Access Journals (Sweden)

    Hugo Cezar Palhares Ferreira

    2016-01-01

    Full Text Available Abstract The binding of information in visual short-term memory may occur incidentally when irrelevant information for the task at hand is stored together with relevant information. We investigated the process of the incidental conjunction of color and shape (Exp1 and its potential association with the selection of relevant information to the memory task (Exp2. The results in Exp1 show that color and shape are incidentally and asymmetrically conjugated: color interferes with the recognition of shape; however, shape does not interfere with the recognition of color. In Exp2, we investigated whether an increase in perceptual load would eliminate the processing of irrelevant information. The results of this experiment show that even with a high perceptual load, the incidental conjunction is not affected, and color remains to interfere with shape recognition, suggesting that the incidental conjunction is an automatic process.

  13. The Interplay between Perceptual Organization and Categorization in the Representation of Complex Visual Patterns by Young Infants

    Science.gov (United States)

    Quinn, Paul C.; Schyns, Philippe G.; Goldstone, Robert L.

    2006-01-01

    The relation between perceptual organization and categorization processes in 3- and 4-month-olds was explored. The question was whether an invariant part abstracted during category learning could interfere with Gestalt organizational processes. A 2003 study by Quinn and Schyns had reported that an initial category familiarization experience in…

  14. Auditory perceptual simulation: Simulating speech rates or accents?

    Science.gov (United States)

    Zhou, Peiyun; Christianson, Kiel

    2016-07-01

    When readers engage in Auditory Perceptual Simulation (APS) during silent reading, they mentally simulate characteristics of voices attributed to a particular speaker or a character depicted in the text. Previous research found that auditory perceptual simulation of a faster native English speaker during silent reading led to shorter reading times that auditory perceptual simulation of a slower non-native English speaker. Yet, it was uncertain whether this difference was triggered by the different speech rates of the speakers, or by the difficulty of simulating an unfamiliar accent. The current study investigates this question by comparing faster Indian-English speech and slower American-English speech in the auditory perceptual simulation paradigm. Analyses of reading times of individual words and the full sentence reveal that the auditory perceptual simulation effect again modulated reading rate, and auditory perceptual simulation of the faster Indian-English speech led to faster reading rates compared to auditory perceptual simulation of the slower American-English speech. The comparison between this experiment and the data from Zhou and Christianson (2016) demonstrate further that the "speakers'" speech rates, rather than the difficulty of simulating a non-native accent, is the primary mechanism underlying auditory perceptual simulation effects.

  15. Harnessing the Wandering Mind: The Role of Perceptual Load

    Science.gov (United States)

    Forster, Sophie; Lavie, Nilli

    2009-01-01

    Perceptual load is a key determinant of distraction by task-irrelevant stimuli (e.g., Lavie, N. (2005). "Distracted and confused?: Selective attention under load." "Trends in Cognitive Sciences," 9, 75-82). Here we establish the role of perceptual load in determining an internal form of distraction by task-unrelated thoughts (TUTs or…

  16. Free-classification of perceptually similar speakers with dysarthria.

    Science.gov (United States)

    Lansford, Kaitlin L; Liss, Julie M; Norton, Rebecca E

    2014-12-01

    In this investigation, the construct of perceptual similarity was explored in the dysarthrias. Specifically, we employed an auditory free-classification task to determine whether listeners could cluster speakers by perceptual similarity, whether the clusters mapped to acoustic metrics, and whether the clusters were constrained by dysarthria subtype diagnosis. Twenty-three listeners blinded to speakers' medical and dysarthria subtype diagnoses participated. The task was to group together (drag and drop) the icons corresponding to 33 speakers with dysarthria on the basis of how similar they sounded. Cluster analysis and multidimensional scaling (MDS) modeled the perceptual dimensions underlying similarity. Acoustic metrics and perceptual judgments were used in correlation analyses to facilitate interpretation of the derived dimensions. Six clusters of similar-sounding speakers and 3 perceptual dimensions underlying similarity were revealed. The clusters of similar-sounding speakers were not constrained by dysarthria subtype diagnosis. The 3 perceptual dimensions revealed by MDS were correlated with metrics for articulation rate, intelligibility, and vocal quality, respectively. This study shows (a) feasibility of a free-classification approach for studying perceptual similarity in dysarthria, (b) correspondence between acoustic and perceptual metrics to clusters of similar-sounding speakers, and (c) similarity judgments transcended dysarthria subtype diagnosis.

  17. Ambiguity Tolerance and Perceptual Learning Styles of Chinese EFL Learners

    Science.gov (United States)

    Li, Haishan; He, Qingshun

    2016-01-01

    Ambiguity tolerance and perceptual learning styles are the two influential elements showing individual differences in EFL learning. This research is intended to explore the relationship between Chinese EFL learners' ambiguity tolerance and their preferred perceptual learning styles. The findings include (1) the learners are sensitive to English…

  18. Perceptual Organization of Visual Structure Requires a Flexible Learning Mechanism

    Science.gov (United States)

    Aslin, Richard N.

    2011-01-01

    Bhatt and Quinn (2011) provide a compelling and comprehensive review of empirical evidence that supports the operation of principles of perceptual organization in young infants. They also have provided a comprehensive list of experiences that could serve to trigger the learning of at least some of these principles of perceptual organization, and…

  19. Perceptual maps: the good, the bad and the ugly

    NARCIS (Netherlands)

    J.C. Gower (John); P.J.F. Groenen (Patrick); M. van de Velden (Michel); K. Vines (Karen)

    2010-01-01

    textabstractPerceptual maps are often used in marketing to visually study relations between two or more attributes. However, in many perceptual maps published in the recent literature it remains unclear what is being shown and how the relations between the points in the map can be interpreted or eve

  20. Perceptual Learning: 12-Month-Olds' Discrimination of Monkey Faces

    Science.gov (United States)

    Fair, Joseph; Flom, Ross; Jones, Jacob; Martin, Justin

    2012-01-01

    Six-month-olds reliably discriminate different monkey and human faces whereas 9-month-olds only discriminate different human faces. It is often falsely assumed that perceptual narrowing reflects a permanent change in perceptual abilities. In 3 experiments, ninety-six 12-month-olds' discrimination of unfamiliar monkey faces was examined. Following…

  1. The Role of Perceptual Load in Object Recognition

    Science.gov (United States)

    Lavie, Nilli; Lin, Zhicheng; Zokaei, Nahid; Thoma, Volker

    2009-01-01

    Predictions from perceptual load theory (Lavie, 1995, 2005) regarding object recognition across the same or different viewpoints were tested. Results showed that high perceptual load reduces distracter recognition levels despite always presenting distracter objects from the same view. They also showed that the levels of distracter recognition were…

  2. Bayesian Face Recognition and Perceptual Narrowing in Face-Space

    Science.gov (United States)

    Balas, Benjamin

    2012-01-01

    During the first year of life, infants' face recognition abilities are subject to "perceptual narrowing", the end result of which is that observers lose the ability to distinguish previously discriminable faces (e.g. other-race faces) from one another. Perceptual narrowing has been reported for faces of different species and different races, in…

  3. Exogenous attention facilitates location transfer of perceptual learning.

    Science.gov (United States)

    Donovan, Ian; Szpiro, Sarit; Carrasco, Marisa

    2015-01-01

    Perceptual skills can be improved through practice on a perceptual task, even in adulthood. Visual perceptual learning is known to be mostly specific to the trained retinal location, which is considered as evidence of neural plasticity in retinotopic early visual cortex. Recent findings demonstrate that transfer of learning to untrained locations can occur under some specific training procedures. Here, we evaluated whether exogenous attention facilitates transfer of perceptual learning to untrained locations, both adjacent to the trained locations (Experiment 1) and distant from them (Experiment 2). The results reveal that attention facilitates transfer of perceptual learning to untrained locations in both experiments, and that this transfer occurs both within and across visual hemifields. These findings show that training with exogenous attention is a powerful regime that is able to overcome the major limitation of location specificity.

  4. Perceptual training narrows the temporal window of multisensory binding

    Science.gov (United States)

    Powers, Albert R.; Hillock, Andrea R.; Wallace, Mark T.

    2009-01-01

    The brain’s ability to bind incoming auditory and visual stimuli depends critically on the temporal structure of this information. Specifically, there exists a temporal window of audiovisual integration within which stimuli are highly likely to be bound together and perceived as part of the same environmental event. Several studies have described the temporal bounds of this window, but few have investigated its malleability. Here, the plasticity in the size of this temporal window was investigated using a perceptual learning paradigm in which participants were given feedback during a two-alternative forced-choice (2-AFC) audiovisual simultaneity judgment task. Training resulted in a marked (i.e., approximately 40%) narrowing in the size of the window. To rule out the possibility that this narrowing was the result of changes in cognitive biases, a second experiment employing a two-interval forced choice (2-IFC) paradigm was undertaken during which participants were instructed to identify a simultaneously-presented audiovisual pair presented within one of two intervals. The 2-IFC paradigm resulted in a narrowing that was similar in both degree and dynamics to that using the 2-AFC approach. Together, these results illustrate that different methods of multisensory perceptual training can result in substantial alterations in the circuits underlying the perception of audiovisual simultaneity. These findings suggest a high degree of flexibility in multisensory temporal processing and have important implications for interventional strategies that may be used to ameliorate clinical conditions (e.g., autism, dyslexia) in which multisensory temporal function may be impaired. PMID:19793985

  5. Perceptual attraction in tool use: evidence for a reliability-based weighting mechanism.

    Science.gov (United States)

    Debats, Nienke B; Ernst, Marc O; Heuer, Herbert

    2017-04-01

    Humans are well able to operate tools whereby their hand movement is linked, via a kinematic transformation, to a spatially distant object moving in a separate plane of motion. An everyday example is controlling a cursor on a computer monitor. Despite these separate reference frames, the perceived positions of the hand and the object were found to be biased toward each other. We propose that this perceptual attraction is based on the principles by which the brain integrates redundant sensory information of single objects or events, known as optimal multisensory integration. That is, 1) sensory information about the hand and the tool are weighted according to their relative reliability (i.e., inverse variances), and 2) the unisensory reliabilities sum up in the integrated estimate. We assessed whether perceptual attraction is consistent with optimal multisensory integration model predictions. We used a cursor-control tool-use task in which we manipulated the relative reliability of the unisensory hand and cursor position estimates. The perceptual biases shifted according to these relative reliabilities, with an additional bias due to contextual factors that were present in experiment 1 but not in experiment 2 The biased position judgments' variances were, however, systematically larger than the predicted optimal variances. Our findings suggest that the perceptual attraction in tool use results from a reliability-based weighting mechanism similar to optimal multisensory integration, but that certain boundary conditions for optimality might not be satisfied.NEW & NOTEWORTHY Kinematic tool use is associated with a perceptual attraction between the spatially separated hand and the effective part of the tool. We provide a formal account for this phenomenon, thereby showing that the process behind it is similar to optimal integration of sensory information relating to single objects. Copyright © 2017 the American Physiological Society.

  6. Perceptual centres in speech - an acoustic analysis

    Science.gov (United States)

    Scott, Sophie Kerttu

    Perceptual centres, or P-centres, represent the perceptual moments of occurrence of acoustic signals - the 'beat' of a sound. P-centres underlie the perception and production of rhythm in perceptually regular speech sequences. P-centres have been modelled both in speech and non speech (music) domains. The three aims of this thesis were toatest out current P-centre models to determine which best accounted for the experimental data bto identify a candidate parameter to map P-centres onto (a local approach) as opposed to the previous global models which rely upon the whole signal to determine the P-centre the final aim was to develop a model of P-centre location which could be applied to speech and non speech signals. The first aim was investigated by a series of experiments in which a) speech from different speakers was investigated to determine whether different models could account for variation between speakers b) whether rendering the amplitude time plot of a speech signal affects the P-centre of the signal c) whether increasing the amplitude at the offset of a speech signal alters P-centres in the production and perception of speech. The second aim was carried out by a) manipulating the rise time of different speech signals to determine whether the P-centre was affected, and whether the type of speech sound ramped affected the P-centre shift b) manipulating the rise time and decay time of a synthetic vowel to determine whether the onset alteration was had more affect on P-centre than the offset manipulation c) and whether the duration of a vowel affected the P-centre, if other attributes (amplitude, spectral contents) were held constant. The third aim - modelling P-centres - was based on these results. The Frequency dependent Amplitude Increase Model of P-centre location (FAIM) was developed using a modelling protocol, the APU GammaTone Filterbank and the speech from different speakers. The P-centres of the stimuli corpus were highly predicted by attributes of

  7. Perception and Cognition in the Ageing Brain: A Brief Review of the Short- and Long-Term Links between Perceptual and Cognitive Decline.

    Science.gov (United States)

    Roberts, Katherine L; Allen, Harriet A

    2016-01-01

    Ageing is associated with declines in both perception and cognition. We review evidence for an interaction between perceptual and cognitive decline in old age. Impoverished perceptual input can increase the cognitive difficulty of tasks, while changes to cognitive strategies can compensate, to some extent, for impaired perception. While there is strong evidence from cross-sectional studies for a link between sensory acuity and cognitive performance in old age, there is not yet compelling evidence from longitudinal studies to suggest that poor perception causes cognitive decline, nor to demonstrate that correcting sensory impairment can improve cognition in the longer term. Most studies have focused on relatively simple measures of sensory (visual and auditory) acuity, but more complex measures of suprathreshold perceptual processes, such as temporal processing, can show a stronger link with cognition. The reviewed evidence underlines the importance of fully accounting for perceptual deficits when investigating cognitive decline in old age.

  8. Cortical Network Dynamics of Perceptual Decision-Making in the Human Brain

    Directory of Open Access Journals (Sweden)

    Markus eSiegel

    2011-02-01

    Full Text Available Goal-directed behavior requires the flexible transformation of sensory evidence about our environment into motor actions. Studies of perceptual decision-making have shown that this transformation is distributed across several widely separated brain regions. Yet, little is known about how decision-making emerges from the dynamic interactions among these regions. Here, we review a series of studies, in which we characterized the cortical network interactions underlying a perceptual decision process in the human brain. We used magnetoencephalography (MEG to measure the large-scale cortical population dynamics underlying each of the sub-processes involved in this decision: the encoding of sensory evidence and action plan, the mapping between the two, and the attentional selection of task-relevant evidence. We found that these sub-processes are mediated by neuronal oscillations within specific frequency ranges. Localized gamma-band oscillations in sensory and motor cortices reflect the encoding of the sensory evidence and motor plan. Large-scale oscillations across widespread cortical networks mediate the integrative processes connecting these local networks: Gamma- and beta-band oscillations across frontal, parietal and sensory cortices serve the selection of relevant sensory evidence and its flexible mapping onto action plans. In sum, our results suggest that perceptual decisions are mediated by oscillatory interactions within overlapping local and large-scale cortical networks.

  9. Temporal characteristics of the influence of punishment on perceptual decision making in the human brain.

    Science.gov (United States)

    Blank, Helen; Biele, Guido; Heekeren, Hauke R; Philiastides, Marios G

    2013-02-27

    Perceptual decision making is the process by which information from sensory systems is combined and used to influence our behavior. In addition to the sensory input, this process can be affected by other factors, such as reward and punishment for correct and incorrect responses. To investigate the temporal dynamics of how monetary punishment influences perceptual decision making in humans, we collected electroencephalography (EEG) data during a perceptual categorization task whereby the punishment level for incorrect responses was parametrically manipulated across blocks of trials. Behaviorally, we observed improved accuracy for high relative to low punishment levels. Using multivariate linear discriminant analysis of the EEG, we identified multiple punishment-induced discriminating components with spatially distinct scalp topographies. Compared with components related to sensory evidence, components discriminating punishment levels appeared later in the trial, suggesting that punishment affects primarily late postsensory, decision-related processing. Crucially, the amplitude of these punishment components across participants was predictive of the size of the behavioral improvements induced by punishment. Finally, trial-by-trial changes in prestimulus oscillatory activity in the alpha and gamma bands were good predictors of the amplitude of these components. We discuss these findings in the context of increased motivation/attention, resulting from increases in punishment, which in turn yields improved decision-related processing.

  10. Vernier perceptual learning transfers to completely untrained retinal locations after double training: a "piggybacking" effect.

    Science.gov (United States)

    Wang, Rui; Zhang, Jun-Yun; Klein, Stanley A; Levi, Dennis M; Yu, Cong

    2014-11-14

    Perceptual learning, a process in which training improves visual discrimination, is often specific to the trained retinal location, and this location specificity is frequently regarded as an indication of neural plasticity in the retinotopic visual cortex. However, our previous studies have shown that "double training" enables location-specific perceptual learning, such as Vernier learning, to completely transfer to a new location where an irrelevant task is practiced. Here we show that Vernier learning can be actuated by less location-specific orientation or motion-direction learning to transfer to completely untrained retinal locations. This "piggybacking" effect occurs even if both tasks are trained at the same retinal location. However, piggybacking does not occur when the Vernier task is paired with a more location-specific contrast-discrimination task. This previously unknown complexity challenges the current understanding of perceptual learning and its specificity/transfer. Orientation and motion-direction learning, but not contrast and Vernier learning, appears to activate a global process that allows learning transfer to untrained locations. Moreover, when paired with orientation or motion-direction learning, Vernier learning may be "piggybacked" by the activated global process to transfer to other untrained retinal locations. How this task-specific global activation process is achieved is as yet unknown.

  11. Gestalt Perceptual Organization of Visual Stimuli Captures Attention Automatically: Electrophysiological Evidence.

    Science.gov (United States)

    Marini, Francesco; Marzi, Carlo A

    2016-01-01

    The visual system leverages organizational regularities of perceptual elements to create meaningful representations of the world. One clear example of such function, which has been formalized in the Gestalt psychology principles, is the perceptual grouping of simple visual elements (e.g., lines and arcs) into unitary objects (e.g., forms and shapes). The present study sought to characterize automatic attentional capture and related cognitive processing of Gestalt-like visual stimuli at the psychophysiological level by using event-related potentials (ERPs). We measured ERPs during a simple visual reaction time task with bilateral presentations of physically matched elements with or without a Gestalt organization. Results showed that Gestalt (vs. non-Gestalt) stimuli are characterized by a larger N2pc together with enhanced ERP amplitudes of non-lateralized components (N1, N2, P3) starting around 150 ms post-stimulus onset. Thus, we conclude that Gestalt stimuli capture attention automatically and entail characteristic psychophysiological signatures at both early and late processing stages. Highlights We studied the neural signatures of the automatic processes of visual attention elicited by Gestalt stimuli. We found that a reliable early correlate of attentional capture turned out to be the N2pc component. Perceptual and cognitive processing of Gestalt stimuli is associated with larger N1, N2, and P3.

  12. Perceptual versus mediational learning in a total change concept-shift paradigm.

    Science.gov (United States)

    Harpur, J G; Estabrooks, K A; Allen, N J; Asaph, C A

    1978-04-01

    The experiment investigated the effects of language acquisition by children in Grades 1 to 4 on performance in a concept-shift task in which the relevant stimulus attributes were either the colour of ink in which a word was written or the meaning of the word. Both English stream and French Immersion children served as subjects. The results indicated a developmental sequence from perceptual learning to verbal mediation. This process was demonstrated at an earlier stage in the French Immersion students who formed a more highly selected group, and intellectual or socio-economic explanations for these differences may be feasible. The relative speed of acquisition of intradimensional and extradimensional shifts interacts with the perceptual/mediational process.

  13. Normative perceptual estimates for 91 healthy subjects age 60-75

    DEFF Research Database (Denmark)

    Wilms, Inge Linda; Nielsen, Simon

    2014-01-01

    Visual perception serves as the basis for much of the higher level cognitive processing as well as human activity in general. Here we present normative estimates for the following components of visual perception: the visual perceptual threshold, the visual short-term memory capacity and the visual...... perceptual encoding/decoding speed (processing speed) of visual short-term memory based on an assessment of 91 healthy subjects aged 60-75. The estimates are presented at total sample level as well as at gender level. The estimates were modelled from input from a whole-report assessment based on A Theory...... speed of Visual Short-term Memory (VTSM) but not the capacity of VSTM nor the visual threshold. The estimates will be useful for future studies into the effects of various types of intervention and training on cognition in general and visual attention in particular....

  14. Predictive codes of familiarity and context during the perceptual learning of facial identities.

    Science.gov (United States)

    Apps, Matthew A J; Tsakiris, Manos

    2013-01-01

    Face recognition is a key component of successful social behaviour. However, the computational processes that underpin perceptual learning and recognition as faces transition from unfamiliar to familiar are poorly understood. In predictive coding, learning occurs through prediction errors that update stimulus familiarity, but recognition is a function of both stimulus and contextual familiarity. Here we show that behavioural responses on a two-option face recognition task can be predicted by the level of contextual and facial familiarity in a computational model derived from predictive-coding principles. Using fMRI, we show that activity in the superior temporal sulcus varies with the contextual familiarity in the model, whereas activity in the fusiform face area covaries with the prediction error parameter that updated facial familiarity. Our results characterize the key computations underpinning the perceptual learning of faces, highlighting that the functional properties of face-processing areas conform to the principles of predictive coding.

  15. Toward a perceptual theory of transparency.

    Science.gov (United States)

    Singh, Manish; Anderson, Barton L

    2002-07-01

    Theories of perceptual transparency have typically been developed within the context of a physical model that generates the percept of transparency (F. Metelli's episcotister model, 1974b). Here 2 fundamental questions are investigated: (a) When does the visual system initiate the percept of one surface seen through another? (b) How does it assign surface properties to a transparent layer? Results reveal systematic deviations from the predictions of Metelli's model, both for initiating image decomposition into multiple surfaces and for assigning surface attributes. Specifically, results demonstrate that the visual system uses Michelson contrast as a critical image variable to initiate percepts of transparency and to assign transmittance to transparent surfaces. Findings are discussed in relation to previous theories of transparency, lightness, brightness, and contrast-contrast.

  16. Confidence leak in perceptual decision-making

    Science.gov (United States)

    Rahnev, Dobromir; Koizumi, Ai; McCurdy, Li Yan; D’Esposito, Mark; Lau, Hakwan

    2015-01-01

    We live in a continuous environment in which the visual scene changes on a slow timescale. It has been shown that, to exploit such environmental stability, the brain creates a “continuity field” such that objects seen seconds ago influence the perception of current objects. What is unknown is whether a similar mechanism exists at the level of our metacognitive representations. In three experiments we demonstrate a robust inter-task “confidence leak” that cannot be explained by response priming or attentional fluctuations. Observers’ ability to modulate this confidence leak predicted higher capacity for metacognition as well as greater gray matter volume in the prefrontal cortex. A model based on normative principles from Bayesian inference explained the results by postulating that observers subjectively estimate the perceptual signal strength in a stable environment. These results point to the existence of a novel metacognitive mechanism mediated by regions in prefrontal cortex. PMID:26408037

  17. Perceptual effects in auralization of virtual rooms

    Science.gov (United States)

    Kleiner, Mendel; Larsson, Pontus; Vastfjall, Daniel; Torres, Rendell R.

    2002-05-01

    By using various types of binaural simulation (or ``auralization'') of physical environments, it is now possible to study basic perceptual issues relevant to room acoustics, as well to simulate the acoustic conditions found in concert halls and other auditoria. Binaural simulation of physical spaces in general is also important to virtual reality systems. This presentation will begin with an overview of the issues encountered in the auralization of room and other environments. We will then discuss the influence of various approximations in room modeling, in particular, edge- and surface scattering, on the perceived room response. Finally, we will discuss cross-modal effects, such as the influence of visual cues on the perception of auditory cues, and the influence of cross-modal effects on the judgement of ``perceived presence'' and the rating of room acoustic quality.

  18. Perceptual grouping determines haptic contextual modulation.

    Science.gov (United States)

    Overvliet, K E; Sayim, B

    2016-09-01

    Since the early phenomenological demonstrations of Gestalt principles, one of the major challenges of Gestalt psychology has been to quantify these principles. Here, we show that contextual modulation, i.e. the influence of context on target perception, can be used as a tool to quantify perceptual grouping in the haptic domain, similar to the visual domain. We investigated the influence of target-flanker grouping on performance in haptic vernier offset discrimination. We hypothesized that when, despite the apparent differences between vision and haptics, similar grouping principles are operational, a similar pattern of flanker interference would be observed in the haptic as in the visual domain. Participants discriminated the offset of a haptic vernier. The vernier was flanked by different flanker configurations: no flankers, single flanking lines, 10 flanking lines, rectangles and single perpendicular lines, varying the degree to which the vernier grouped with the flankers. Additionally, we used two different flanker widths (same width as and narrower than the target), again to vary target-flanker grouping. Our results show a clear effect of flankers: performance was much better when the vernier was presented alone compared to when it was presented with flankers. In the majority of flanker configurations, grouping between the target and the flankers determined the strength of interference, similar to the visual domain. However, in the same width rectangular flanker condition we found aberrant results. We discuss the results of our study in light of similarities and differences between vision and haptics and the interaction between different grouping principles. We conclude that in haptics, similar organization principles apply as in visual perception and argue that grouping and Gestalt are key organization principles not only of vision, but of the perceptual system in general.

  19. Perceptual pitch deficits coexist with pitch production difficulties in music but not Mandarin speech

    OpenAIRE

    Wu-xia eYang; Jie eFeng; Wan-ting eHuang; Cheng-xiang eZhang; Yun eNan

    2014-01-01

    Congenital amusia is a musical disorder that mainly affects pitch perception. Among Mandarin speakers, some amusics also have difficulties in processing lexical tones (tone agnosics). To examine to what extent these perceptual deficits may be related to pitch production impairments in music and Mandarin speech, eight amusics, eight tone agnosics, and 12 age- and IQ-matched normal native Mandarin speakers were asked to imitate music note sequences and Mandarin words of comparable lengths. The ...

  20. Auditory-perceptual learning improves speech motor adaptation in children.

    Science.gov (United States)

    Shiller, Douglas M; Rochon, Marie-Lyne

    2014-08-01

    Auditory feedback plays an important role in children's speech development by providing the child with information about speech outcomes that is used to learn and fine-tune speech motor plans. The use of auditory feedback in speech motor learning has been extensively studied in adults by examining oral motor responses to manipulations of auditory feedback during speech production. Children are also capable of adapting speech motor patterns to perceived changes in auditory feedback; however, it is not known whether their capacity for motor learning is limited by immature auditory-perceptual abilities. Here, the link between speech perceptual ability and the capacity for motor learning was explored in two groups of 5- to 7-year-old children who underwent a period of auditory perceptual training followed by tests of speech motor adaptation to altered auditory feedback. One group received perceptual training on a speech acoustic property relevant to the motor task while a control group received perceptual training on an irrelevant speech contrast. Learned perceptual improvements led to an enhancement in speech motor adaptation (proportional to the perceptual change) only for the experimental group. The results indicate that children's ability to perceive relevant speech acoustic properties has a direct influence on their capacity for sensory-based speech motor adaptation.