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Sample records for eye blink response

  1. Blink Animation Software to Improve Blinking and Dry Eye Symptoms.

    Science.gov (United States)

    Nosch, Daniela S; Foppa, Curdin; Tóth, Mike; Joos, Roland E

    2015-09-01

    To evaluate if the animation "blink blink" increases blink rate and improves dry eye symptoms during prolonged computer use. Study part A: Blink rate was recorded at baseline and during computer work of normal subjects without symptoms of dry eye. Half of the subjects used "blink blink," instructed to blink on animation appearance; the other half used a placebo version for 1 week during computer use. Thereafter, blink rate was recorded again with the use of "blink blink." Study part B: Blink rate was recorded during computer work with dry eye symptoms (modified Ocular Surface Disease Index > 15.0). Subjects used the test and placebo version of "blink blink" each for 1 week (1 week washout; crossover) and were instructed to blink twice on presentation of the animation. Blink rate and dry eye symptoms were assessed after each phase and compared with baseline. Study part A: Ten subjects participated (mean [± SD] age, 38.3 [± 16.0] years; 5 women). A greater increase in blink rate was observed in the test group (5.62 blinks/min for the test group and 0.96 blinks/min for the control group). Study part B: Twenty-four subjects participated (mean [± SD] age, 39.3 [± 19.1] years; 11 women). Dry eye symptoms improved during both phases (with test and placebo) to a statistically significant degree (each, p animation allowed a decrease in number of presentations and improved acceptance of "blink blink."

  2. Spontaneous eye blinks during creative task correlate with divergent processing.

    Science.gov (United States)

    Ueda, Yoshiyuki; Tominaga, Atsuko; Kajimura, Shogo; Nomura, Michio

    2016-07-01

    Creativity consists of divergent and convergent thinking, with both related to individual eye blinks at rest. To assess underlying mechanisms between eye blinks and traditional creativity tasks, we investigated the relationship between creativity performance and eye blinks at rest and during tasks. Participants performed an alternative uses and remote association task while eye blinks were recorded. Results showed that the relationship between eye blinks at rest and creativity performance was compatible with those of previous research. Interestingly, we found that the generation of ideas increased as a function of eye blink number during the alternative uses task. On the other hand, during the remote association task, accuracy was independent of eye blink number during the task, but response time increased with it. Moreover, eye blink changes in participants who responded quickly during the remote association task were different depending on their resting state eye blinks; that is, participants with many eye blinks during rest showed little increasing eye blinks and achieved solutions quickly. Positive correlations between eye blinks during creative tasks and yielding ideas on the alternative uses task and response time on the remote association task suggest that eye blinks during creativity tasks relate to divergent thinking processes such as conceptual reorganization.

  3. Reconstruction of eye movements during blinks

    CERN Document Server

    Baptista, M S; Kliegl, R; Engbert, R; Kurths, J

    2008-01-01

    In eye movement research in reading, the amount of data plays a crucial role for the validation of results. A methodological problem for the analysis of the eye movement in reading are blinks, when readers close their eyes. Blinking rate increases with increasing reading time, resulting in high data losses, especially for older adults or reading impaired subjects. We present a method, based on the symbolic sequence dynamics of the eye movements, that reconstructs the horizontal position of the eyes while the reader blinks. The method makes use of an observed fact that the movements of the eyes before closing or after opening contain information about the eyes movements during blinks. Test results indicate that our reconstruction method is superior to methods that use simpler interpolation approaches. In addition, analyses of the reconstructed data show no significant deviation from the usual behavior observed in readers.

  4. Short-term memory across eye blinks.

    Science.gov (United States)

    Irwin, David E

    2014-01-01

    The effect of eye blinks on short-term memory was examined in two experiments. On each trial, participants viewed an initial display of coloured, oriented lines, then after a retention interval they viewed a test display that was either identical or different by one feature. Participants kept their eyes open throughout the retention interval on some blocks of trials, whereas on others they made a single eye blink. Accuracy was measured as a function of the number of items in the display to determine the capacity of short-term memory on blink and no-blink trials. In separate blocks of trials participants were instructed to remember colour only, orientation only, or both colour and orientation. Eye blinks reduced short-term memory capacity by approximately 0.6-0.8 items for both feature and conjunction stimuli. A third, control, experiment showed that a button press during the retention interval had no effect on short-term memory capacity, indicating that the effect of an eye blink was not due to general motoric dual-task interference. Eye blinks might instead reduce short-term memory capacity by interfering with attention-based rehearsal processes.

  5. High-speed camera characterization of voluntary eye blinking kinematics.

    Science.gov (United States)

    Kwon, Kyung-Ah; Shipley, Rebecca J; Edirisinghe, Mohan; Ezra, Daniel G; Rose, Geoff; Best, Serena M; Cameron, Ruth E

    2013-08-01

    Blinking is vital to maintain the integrity of the ocular surface and its characteristics such as blink duration and speed can vary significantly, depending on the health of the eyes. The blink is so rapid that special techniques are required to characterize it. In this study, a high-speed camera was used to record and characterize voluntary blinking. The blinking motion of 25 healthy volunteers was recorded at 600 frames per second. Master curves for the palpebral aperture and blinking speed were constructed using palpebral aperture versus time data taken from the high-speed camera recordings, which show that one blink can be divided into four phases; closing, closed, early opening and late opening. Analysis of data from the high-speed camera images was used to calculate the palpebral aperture, peak blinking speed, average blinking speed and duration of voluntary blinking and compare it with data generated by other methods previously used to evaluate voluntary blinking. The advantages of the high-speed camera method over the others are discussed, thereby supporting the high potential usefulness of the method in clinical research.

  6. Effect of varying the intensity and train frequency of forelimb and cerebellar mossy fiber conditioned stimuli on the latency of conditioned eye-blink responses in decerebrate ferrets.

    Science.gov (United States)

    Svensson, P; Ivarsson, M; Hesslow, G

    1997-01-01

    To study the role of the mossy fiber afferents to the cerebellum in classical eye-blink conditioning, in particular the timing of the conditioned responses, we compared the effects of varying a peripheral conditioned stimulus with the effects of corresponding variations of direct stimulation of the mossy fibers. In one set of experiments, decerebrate ferrets were trained in a Pavlovian eye-blink conditioning paradigm with electrical forelimb train stimulation as conditioned stimulus and electrical periorbital stimulation as the unconditioned stimulus. When stable conditioning had been achieved, the effect of increasing the intensity or frequency of the forelimb stimulation was tested. By increasing the intensity from 1 to 2 mA, or the train frequency from 50 to 100 Hz, an immediate decrease was induced in both the onset latency and the latency to peak of the conditioned response. If the conditioned stimulus intensity/frequency was maintained at the higher level, the response latencies gradually returned to preshift values. In a second set of experiments, the forelimb stimulation was replaced by direct train stimulation of the middle cerebellar peduncle as conditioned stimulus. Varying the frequency of the stimulus train between 50 and 100 Hz had effects that were almost identical to those obtained when using a forelimb conditioned stimulus. The functional meaning of the latency effect is discussed. It is also suggested that the results support the view that the conditioned stimulus is transmitted through the mossy fibers and that the mechanism for timing the conditioned response is situated in the cerebellum.

  7. Eye blink frequency during different computer tasks quantified by electrooculography

    DEFF Research Database (Denmark)

    Skotte, J H; Nøjgaard, J K; Jørgensen, L V;

    2007-01-01

    The purpose of the study was to evaluate electrooculography (EOG) as an automatic method to measure the human eye blink frequency (BF) during passive and interactive computer tasks performed at two screen heights. Ten healthy subjects (5 males and 5 females) participated in the study in a 23...... degrees C temperature and 30-35% relative humidity controlled simulated office environment. Each test subject completed a 2 x 10 min active task of computer work and a 3 x 10 min passive task of watching a film on a video display unit (VDU). Both tasks included two viewing angles: standard (the monitors...... counted manually from the video recordings and compared to the EOG measurements. The method showed a high validity to detect blinks during computer work: 95.4% of the blinks were retrieved by the EOG method and very few artefacts from eye movements were erroneously classified as eye blinks (2.4%). By use...

  8. Detection of eye blink artifacts from single prefrontal channel electroencephalogram.

    Science.gov (United States)

    Chang, Won-Du; Cha, Ho-Seung; Kim, Kiwoong; Im, Chang-Hwan

    2016-02-01

    Eye blinks are one of the most influential artifact sources in electroencephalogram (EEG) recorded from frontal channels, and thereby detecting and rejecting eye blink artifacts is regarded as an essential procedure for improving the quality of EEG data. In this paper, a novel method to detect eye blink artifacts from a single-channel frontal EEG signal was proposed by combining digital filters with a rule-based decision system, and its performance was validated using an EEG dataset recorded from 24 healthy participants. The proposed method has two main advantages over the conventional methods. First, it uses single-channel EEG data without the need for electrooculogram references. Therefore, this method could be particularly useful in brain-computer interface applications using headband-type wearable EEG devices with a few frontal EEG channels. Second, this method could estimate the ranges of eye blink artifacts accurately. Our experimental results demonstrated that the artifact range estimated using our method was more accurate than that from the conventional methods, and thus, the overall accuracy of detecting epochs contaminated by eye blink artifacts was markedly increased as compared to conventional methods. The MATLAB package of our library source codes and sample data, named Eyeblink Master, is open for free download.

  9. Unilateral Eye Blinking Arising From the Ictal Ipsilateral Occipital Area.

    Science.gov (United States)

    Falsaperla, Raffaele; Perciavalle, Valentina; Pavone, Piero; Praticò, Andrea Domenico; Elia, Maurizio; Ruggieri, Martino; Caraballo, Roberto; Striano, Pasquale

    2016-07-01

    We report on an 18-month-old boy with unilateral left eye blinking as a single ictal manifestation without facial twitching. The clinical onset of this phenomenon was first recorded (as an occasional event) at age 3 months, and it was overlooked. By age 6 months, the child's blinking increased to almost daily occurrence in clusters: during blinking the infant showed intact awareness and occasional jerks in the upper limbs and right leg. A video-electroencephalography (video-EEG) documented clinical correlation with a focal pattern arising from the left occipital region, and brain magnetic resonance imaging (MRI) revealed severe brain damage, consisting in poroencephalic hollows and increased spaces in the convexities involving a large area of the left cerebral hemisphere. The boy was prescribed sodium valproate (30 mg/kg/d), resulting in drastic reduction of his clinical seizures. Follow-up to his current age documented good general status, with persistent partial right hemilateral seizures. The blinking progressively disappeared, and is no longer recorded. The pathogenic hypotheses of the unilateral ictal blinking include involvement of the ipsilateral cerebral hemisphere and/or the cerebellar pathways. Review of previous reports of unilateral eye blinking, arising from the ictal ipsilateral brain, revealed that different damaged regions may give rise to blinking ictal phenomena, likely via the trigeminal fibres innervating the subdural intracranial structures and the pial vessels in the ipsilateral affected brain. The eye blinking in the present child represents a further example of an ictal phenomenon, which is predictive of the damaged brain region.

  10. Quantitative study of spontaneous eye blinks and eye tics in Gilles de la Tourette's syndrome

    NARCIS (Netherlands)

    J.H.M. Tulen (Joke); M. Azzolini; J.A. de Vries; W.H. Groeneveld; J. Passchier (Jan); B.J.M. van de Wetering (Ben)

    1999-01-01

    textabstractSpontaneous eye blink rate and frequency of eye tics were studied in nine Tourette patients during periods of rest, conversation, and video watching. In comparison with controls, the Tourette patients showed a significantly higher blink rate during rest and

  11. Accident Prevention by Eye Blinking Sensor and Alcohol Detector

    Directory of Open Access Journals (Sweden)

    Deepa K B, Chaitra M

    2015-07-01

    Full Text Available This system provides a unique method to curb drunken and drowsy people. This system has an alcohol sensor and eye blinking sensor embedded in the vehicles. Whenever the driver start vehicle, the sensors senses the eye blink and measures the content of alcohol in his breathe and automatically sends the signal to buzzer, gsm and lcd. In this system the outputs of sensors are given to the microcontroller for comparison. If the value reaches to fixed limit then automatically gsm will send the sms, buzzer will produces sound and lcd will display the message.

  12. Using Eye Blinking for EOG-Based Robot Control

    Science.gov (United States)

    Duguleana, Mihai; Mogan, Gheorghe

    This paper proposes a new approach to real-time robot controlling by integrating an Electrooculography (EOG) measuring device within human-robot interaction (HRI). Our study focuses on controlling robots using EOG for fulfilling elementary robot activities such as basic motor movements and environment interaction. A new EOG-based HRI paradigm has been developed on the specific defined problem of eye blinking. The resulted model is tested using biometric capturing equipment. We propose a simple algorithm for real-time identification and processing of signals produced by eyes during blinking phases. We present the experimental setup and the results of the experiment. We conclude by listing further research issues.

  13. The relationship between eye-winking tics, frequent eye-blinking and blepharospasm.

    Science.gov (United States)

    Elston, J S; Granje, F C; Lees, A J

    1989-04-01

    A family is reported in which three generations were affected with eye-winking tics and/or blepharospasm. The proband developed eye-winking tics in childhood and then developed excessive blinking progressing to blepharospasm by the age of 21 years. His mother presented with Meige's syndrome and spasmodic torticollis at the age of 59 years; his uncle had blinked excessively from his early forties. His eldest son developed an eye-winking tic with facial grimacing at the age of 8 years, and in another son, a self-limiting period of eye-blinking occurred at the age of 4 years. The recovery cycle of the blink reflex was abnormal in all three generations. Three other children with eye-winking tics have a parent or close relative with frequent eye-blinking or blepharospasm. Five patients with adult-onset blepharospasm or Meige's syndrome are also described who had excessive eye-blinking dating back to childhood. It is suggested that eye-winking tics, frequent blinking and blepharospasm may share common pathophysiological mechanisms; the clinical expression may be age-related.

  14. Simultaneous Eye Tracking and Blink Detection with Interactive Particle Filters

    Directory of Open Access Journals (Sweden)

    Mohan M. Trivedi

    2008-04-01

    Full Text Available We present a system that simultaneously tracks eyes and detects eye blinks. Two interactive particle filters are used for this purpose, one for the closed eyes and the other one for the open eyes. Each particle filter is used to track the eye locations as well as the scales of the eye subjects. The set of particles that gives higher confidence is defined as the primary set and the other one is defined as the secondary set. The eye location is estimated by the primary particle filter, and whether the eye status is open or closed is also decided by the label of the primary particle filter. When a new frame comes, the secondary particle filter is reinitialized according to the estimates from the primary particle filter. We use autoregression models for describing the state transition and a classification-based model for measuring the observation. Tensor subspace analysis is used for feature extraction which is followed by a logistic regression model to give the posterior estimation. The performance is carefully evaluated from two aspects: the blink detection rate and the tracking accuracy. The blink detection rate is evaluated using videos from varying scenarios, and the tracking accuracy is given by comparing with the benchmark data obtained using the Vicon motion capturing system. The setup for obtaining benchmark data for tracking accuracy evaluation is presented and experimental results are shown. Extensive experimental evaluations validate the capability of the algorithm.

  15. Evidence that Illness-Compatible Cues Are Rewarding in Women Recovered from Anorexia Nervosa: A Study of the Effects of Dopamine Depletion on Eye-Blink Startle Responses

    Science.gov (United States)

    O’Hara, Caitlin B.; Keyes, Alexandra; Renwick, Bethany; Giel, Katrin E.; Campbell, Iain C.; Schmidt, Ulrike

    2016-01-01

    In anorexia nervosa (AN), motivational salience is attributed to illness-compatible cues (e.g., underweight and active female bodies) and this is hypothesised to involve dopaminergic reward circuitry. We investigated the effects of reducing dopamine (DA) transmission on the motivational processing of AN-compatible cues in women recovered from AN (AN REC, n = 17) and healthy controls (HC, n = 15). This involved the acute phenylalanine and tyrosine depletion (APTD) procedure and a startle eye-blink modulation (SEM) task. In a balanced amino acid state, AN REC showed an increased appetitive response (decreased startle potentiation) to illness-compatible cues (underweight and active female body pictures (relative to neutral and non-active cues, respectively)). The HC had an aversive response (increased startle potentiation) to the same illness-compatible stimuli (relative to neutral cues). Importantly, these effects, which may be taken to resemble symptoms observed in the acute stage of illness and healthy behaviour respectively, were not present when DA was depleted. Thus, AN REC implicitly appraised underweight and exercise cues as more rewarding than did HC and the process may, in part, be DA-dependent. It is proposed that the positive motivational salience attributed to cues of emaciation and physical activity is, in part, mediated by dopaminergic reward processes and this contributes to illness pathology. These observations are consistent with the proposal that, in AN, aberrant reward-based learning contributes to the development of habituation of AN-compatible behaviours. PMID:27764214

  16. Efficient Eye Blink Detection Method for disabled-helping domain

    Directory of Open Access Journals (Sweden)

    Assit. Prof. Aree A. Mohammed

    2014-06-01

    Full Text Available In this paper, we present a real time method based on some video and image processing algorithms for eye blink detection. The motivation of this research is the need of disabling who cannot control the calls with human mobile interaction directly without the need of hands. A Haar Cascade Classifier is applied for face and eye detection for getting eye and facial axis information. In addition, the same classifier is used based on Haar- like features to find out the relationship between the eyes and the facial axis for positioning the eyes. An efficient eye tracking method is proposed which uses the position of detected face. Finally, an eye blinking detection based on eyelids state (close or open is used for controlling android mobile phones. The method is used with and without smoothing filter to show the improvement of detection accuracy. The application is used in real time for studying the effect of light and distance between the eyes and the mobile device in order to evaluate the accuracy detection and overall accuracy of the system. Test results show that our proposed method provides a 98% overall accuracy and 100% detection accuracy for a distance of 35 cm and an artificial light.

  17. Investigation of extended blinks and interblink intervals in subjects with and without dry eye

    Directory of Open Access Journals (Sweden)

    Rodriguez JD

    2013-02-01

    Full Text Available John D Rodriguez,1 George W Ousler III,1 Patrick R Johnston,1 Keith Lane,1 Mark B Abelson1,21Ora, Inc, Andover, MA, 2Schepens Eye Research Institute and Harvard Medical School, Boston, MA, USABackground: The purpose of this study was to investigate the occurrence and duration of extended blinks ≥ 70 msec and their associated interblink intervals in normal subjects and in subjects with mild to moderate dry eye.Methods: This single-center, prospective, double-blind study included 11 subjects with dry eye and eight subjects with normal eyes. Extended blinks were defined as lid closure in at least two successive video frames (≥ 70 msec. Digital video imaging of each subject's eyes was recorded while the subject viewed a 10-minute documentary. The subjects did not know that blink was the outcome being measured. Following capture, the videos were manually analyzed in a masked fashion for the occurrence of extended blinks. The length of the interblink interval (ie, time between blinks before and after these extended blinks (the interblink interval ratio was calculated, as well as differences in lid contact times.Results: The dry eye group had a median extended blink duration which was 2.53 times longer than that of the normal group. For subjects with dry eye, interblink intervals post-extended blink were significantly longer than interblink intervals pre-extended blink (P < 0.001. Interblink intervals did not lengthen significantly in normal subjects. In both groups, the duration of the extended blink was significantly (P = 0.001 and positively correlated with interblink interval ratio (post-extended to pre-extended blink interblink interval, such that for each doubling of extended blink duration, the interblink interval ratio increased by 10%. Blinks longer than one second in duration occurred almost exclusively in subjects with dry eye.Conclusion: This study reports three central findings: blink duration tended to be longer in subjects with dry

  18. In the twinkling of an eye: synchronization of EEG and eye tracking based on blink signatures

    DEFF Research Database (Denmark)

    Bækgaard, Per; Petersen, Michael Kai; Larsen, Jakob Eg

    2014-01-01

    be integrated into next generation user interfaces. In experimental lab settings EEG neuroimaging and eye tracking data are traditionally combined using external triggers to synchronize the signals. However, with biometric sensors increasingly being applied in everyday usage scenarios, there will be a need...... for solutions providing a continuous alignment of signals. In the present paper we propose using spontaneous eye blinks, as a means to achieve near real-time synchronization of EEG and eye tracking. Analyzing key parameters that define eye blink signatures across the two domains, we outline a probability...... function based algorithm to correlate the signals. Comparing the accuracy of the method against a state of the art EYE-EEG plug-in for offline analysis of EEG and eye tracking data, we propose our approach could be applied for robust synchronization of biometric sensor data collected in a mobile context....

  19. Does Repeated Ticking Maintain Tic Behavior? An Experimental Study of Eye Blinking in Healthy Individuals

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    Daniel J. V. Beetsma

    2013-01-01

    Full Text Available Tics in Tourette Syndrome (TS are often preceded by 'premonitory urges': annoying feelings or bodily sensations. We hypothesized that, by reducing annoyance of premonitory urges, tic behaviour may be reinforced. In a 2X2 experimental design in healthy participants, we studied the effects of premonitory urges (operationalized as air puffs on the eye and tic behaviour (deliberate eye blinking after a puff or a sound on changes in subjective evaluation of air puffs, and EMG responses on the m. orbicularis oculi. The experimental group with air puffs+ blinking experienced a decrease in subjective annoyance of the air puff, but habituation of the EMG response was blocked and length of EMG response increased. In the control groups (air puffs without instruction to blink, no air puffs, these effects were absent. When extrapolating to the situation in TS patients, these findings suggest that performance of tics is reinforced by reducing the subjective annoyance of premonitory urges, while simultaneously preventing habituation or even inducing sensitisation of the physiological motor response.

  20. The (B)link Between Creativity and Dopamine: Spontaneous Eye Blink Rates Predict and Dissociate Divergent and Convergent Thinking

    Science.gov (United States)

    Chermahini, Soghra Akbari; Hommel, Bernhard

    2010-01-01

    Human creativity has been claimed to rely on the neurotransmitter dopamine, but evidence is still sparse. We studied whether individual performance (N=117) in divergent thinking (alternative uses task) and convergent thinking (remote association task) can be predicted by the individual spontaneous eye blink rate (EBR), a clinical marker of…

  1. A New EEG Acquisition Protocol for Biometric Identification Using Eye Blinking Signals

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    M. Abo-Zahhad

    2015-05-01

    Full Text Available In this paper, a new acquisition protocol is adopted for identifying individuals from electroencephalogram signals based on eye blinking waveforms. For this purpose, a database of 10 subjects is collected using Neurosky Mindwave headset. Then, the eye blinking signal is extracted from brain wave recordings and used for the identification task. The feature extraction stage includes fitting the extracted eye blinks to auto-regressive model. Two algorithms are implemented for auto-regressive modeling namely; Levinson-Durbin and Burg algorithms. Then, discriminant analysis is adopted for classification scheme. Linear and quadratic discriminant functions are tested and compared in this paper. Using Burg algorithm with linear discriminant analysis, the proposed system can identify subjects with best accuracy of 99.8%. The obtained results in this paper confirm that eye blinking waveform carries discriminant information and is therefore appropriate as a basis for person identification methods.

  2. Blink patterns and lid-contact times in dry-eye and normal subjects

    Directory of Open Access Journals (Sweden)

    Ousler GW 3rd

    2014-05-01

    Full Text Available George W Ousler 3rd,1 Mark B Abelson,1,2 Patrick R Johnston,1 John Rodriguez,1 Keith Lane,1 Lisa M Smith11Ora, Andover, MA, USA; 2Department of Ophthalmology, Harvard Medical School, Boston, MA, USAPurpose: To classify blinks in dry eye and normal subjects into six subtypes, and to define the blink rate and duration within each type of blink, as well as the total lid-contact time/minute.Materials and methods: This was a single-centered, prospective, double-blind study of eleven dry-eye and ten normal subjects. Predefined subjects watched a video while blinks were recorded for 10 minutes. Partial blinks were classified by percentage closure of maximal palpebral fissure opening: 25%, 50%, 75%. Complete blinks were characterized as full (>0 seconds, extended (>0.1 seconds, or superextended (>0.5 seconds. The mean duration of each type of blink was determined and standardized per minute as total lid-contact time.Results: Total blinks observed were 4,990 (1,414 normal, 3,756 dry eye: 1,809 (50.59% partial and 1,767 (49.41% complete blinks among dry-eye subjects versus 741 (52.90% partial and 673 (47.60% complete blinks among normal subjects. Only superextended blinks of ≥0.5-second duration were significantly more frequent in dry-eye subjects than normals (2.3% versus 0.2%, respectively; P=0.023. Total contact time was seven times higher in dry-eye subjects than normals (0.565 versus 0.080 seconds, respectively; P<0.001. Isolating only extended blinks (>0.1 second, the average contact time (seconds was four times longer in dry-eye versus normal subjects (2.459 in dry eye, 0.575 in normals; P=0.003. Isolating only superextended blinks (>0.5 seconds, average contact time was also significantly different (7.134 in dry eye, 1.589 in normals; P<0.001. The contact rate for all full closures was 6.4 times longer in dry-eye (0.045 versus 0.007, P<0.001 than normal subjects.Conclusion: Dry-eye subjects spent 4.5% of a

  3. Dopamine activation in Neuroticism as measured by spontaneous eye blink rate.

    Science.gov (United States)

    Barbato, Giuseppe; Della Monica, Ciro; Costanzo, Antonio; De Padova, Vittoria

    2012-01-18

    Personality dimensions have been associated with different psychobiological systems. However, no agreement exists in literature on a specific role of a single neurotransmitter for each of the dimensions investigated. We studied the relationship of Neuroticism, Extraversion and Psychoticism as assessed by Eysenck Personality Inventory (EPI) with spontaneous eye blink rate (BR), a non-invasive measure of central dopamine activity. A total of sixty-three healthy subjects (40 females, 23 males, mean age 24.2±3.9) were studied. Spontaneous blink rate and time of blink suppression were assessed by EOG measurement. Levels of Extraversion and Neuroticism were inversely correlated. In contrast with previous findings, a significant correlation between blink rate measures and Neuroticism was found. No significant correlation between blink measures and either Extraversion, or Psychoticism were found. The results appear consistent with a lower threshold for activation in neuroticism as suggested by Eysenck's original model.

  4. Pre-pulse inhibition of the acoustic startle eye-blink in the Göttingen minipig

    DEFF Research Database (Denmark)

    Arnfred, Sidse Marie; Lind, Nanna Marie; Hansen, Axel Kornerup;

    2004-01-01

    by a weak white noise pre-pulse (PP), the interval between the PP and the startle noise stimulus (SNS) determining the degree of inhibition. Aiming at developing a new animal model of schizophrenia, we have investigated the acoustic startle eye-blink and PPI in 10 Göttingen minipigs. The stimuli......Pre-pulse inhibition (PPI) of the startle response is a measure of sensorimotor gating which has been frequently shown to be deficient in schizophrenic patients. In humans it is typically measured as the attenuation of the startle eye-blink reflex EMG when a startle eliciting noise is preceded...... and the block design of the stimulation were similar to paradigms used in human research. Initially the startle habituation across trials and blocks, secondarily the PPI at PP to SNS intervals of 30, 60, 120, 220, 520, 1020 and 2020 ms was investigated. One pig out of ten did not have a startle response...

  5. Spontaneous eye blink rate predicts learning from negative, but not positive, outcomes

    NARCIS (Netherlands)

    Slagter, H.A.; Georgopoulou, K.; Frank, M.J.

    2015-01-01

    A large body of research shows that striatal dopamine critically affects the extent to which we learn from the positive and negative outcomes of our decisions. In this study, we examined the relationship between reinforcement learning and spontaneous eye blink rate (sEBR), a cheap, non-invasive, and

  6. Ocular surface area and human eye blink frequency during VDU work

    DEFF Research Database (Denmark)

    Nielsen, Pernille Kofoed; Søgaard, Karen; Skotte, Jørgen

    2008-01-01

    The purpose of this study was to investigate how the ocular surface area (OSA) and the eye blink frequency (BF) are affected by a high versus a low-monitor position during visual display unit (VDU) work with varying cognitive demands. In a balanced randomized (2 x 2) design ten healthy subjects....... The low BF during the active task was succeded by a burst with high BF after cessation of the active task, indicating a compensatory blinking process. This stresses that interchange of work tasks with different cognitive load is as important as the monitor position in the prevention of visual...

  7. Closing one's eyes to reality: evidence for a dopaminergic basis of psychoticism from spontaneous eye blink rates

    NARCIS (Netherlands)

    L.S. Colzato; H.A. Slagter; W.P.M. van den Wildenberg; B. Hommel

    2009-01-01

    We tested the idea that Psychoticism, a major personality dimension, is rooted in individual differences in dopamine functioning. To this end, we related the spontaneous eye blink rate (EBR), a marker of striatal dopaminergic activity, to scores in the Eysenck Personality Questionnaire Revised Short

  8. Somatosensory-evoked blink response: investigation of the physiological mechanisms.

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    Miwa, H; Nohara, C; Hotta, M; Shimo, Y; Amemiya, K

    1998-02-01

    The somatosensory-evoked blink response (SBR) is a newly identified blink reflex elicited by electrical stimulation of peripheral nerves. The present study was performed to investigate the physiological mechanism underlying the SBR elicited by median nerve stimulation in normal subjects. The peripheral afferents responsible for the SBR included low-threshold cutaneous fibres. In the SBR-positive subjects, the late (R2) component of the blink reflex elicited by supraorbital nerve stimulation and the SBR facilitated each other when both responses were induced at the same time, but they each caused long-lasting inhibition in the other when one stimulus was given as a conditioning stimulus. The extent of inhibition was correlated with the size of the preceding SBR. In the SBR-negative subjects, simultaneous inhibition of R2 was observed when median nerve stimulation was applied as a conditioning stimulus. Brainstem excitability, as evaluated by blink-reflex recovery studies, did not differ between SBR-positive and SBR-negative subjects. Therefore, based on anatomical and physiological findings, it appears that the reflex pathways of the SBR and R2 converge within the brainstem and compete with each other, presumably by presynaptic inhibition at the premotor level, before entering the common blink-reflex pathway. The influence of median nerve stimulation upon tonic contraction of the orbicularis oculi muscle was studied to detect the latent SBR. There was not only a facilitatory period corresponding to the SBR but also an active inhibitory period (exteroceptive suppression), suggesting that the mechanism generating the SBR is not only influenced by blink-reflex volleys but also by active exteroceptive suppression. Thus, the SBR may appear as a result of integration of facilitatory and inhibitory mechanisms within the brainstem.

  9. Low Dimensional Temporal Organization of Spontaneous Eye Blinks in Adults with Developmental Disabilities and Stereotyped Movement Disorder

    Science.gov (United States)

    Lee, Mei-Hua; Bodfish, James W.; Lewis, Mark H.; Newell, Karl M.

    2010-01-01

    This study investigated the mean rate and time-dependent sequential organization of spontaneous eye blinks in adults with intellectual and developmental disability (IDD) and individuals from this group who were additionally categorized with stereotypic movement disorder (IDD + SMD). The mean blink rate was lower in the IDD + SMD group than the IDD…

  10. Impaired eye-blink conditioning in waggler, a mutant mouse with cerebellar BDNF deficiency.

    Science.gov (United States)

    Bao, S; Chen, L; Qiao, X; Knusel, B; Thompson, R F

    1998-01-01

    In addition to their trophic functions, neurotrophins are also implicated in synaptic modulation and learning and memory. Although gene knockout techniques have been used widely in studying the roles of neurotrophins at molecular and cellular levels, behavioral studies using neurotrophin knockouts are limited by the early-onset lethality and various sensory deficits associated with the gene knockout mice. In the present study, we found that in a spontaneous mutant mouse, waggler, the expression of brain-derived neurotrophic factor (BDNF) was selectively absent in the cerebellar granule cells. The cytoarchitecture of the waggler cerebellum appeared to be normal at the light microscope level. The mutant mice exhibited no sensory deficits to auditory stimuli or heat-induced pain. However, they were massively impaired in classic eye-blink conditioning. These results suggest that BDNF may have a role in normal cerebellar neuronal function, which, in turn, is essential for classic eye-blink conditioning.

  11. Startle eye-blink modulation by facial self-resemblance and current mood.

    Science.gov (United States)

    Finke, Johannes B; Larra, Mauro F; Schilling, Thomas M; Lass-Hennemann, Johanna; Blumenthal, Terry D; Schächinger, Hartmut

    2015-06-01

    Although salient stimuli are known to modulate startle eye-blink responses, and one's own face is considered of particular salience, effects of facial self-resemblance on startle responsiveness have not been systematically investigated. For the present study, pictures from the FACES database (rated as neutral) were digitally morphed to resemble the participants' (N=37) faces to varying degrees (25-50-75%). Perceptually matched geometrical shapes served as a control condition. At SOAs of either 300ms or 3000ms after picture onset, startle responses were elicited by white noise (50ms, 105dB), and recorded at the orbicularis oculi via EMG. Prior to the experiment, self-reported mood was assessed by means of the PANAS. Relative to non-face stimuli, the presentation of faces reduced startle magnitude at short, but not long, lead intervals. Furthermore, for probes presented at a SOA of 300ms, a linear decrease in startle magnitude with higher levels of self-resemblance was observed, presumably reflecting higher salience of the self-face. The startle modulating effect of self-resembling faces during longer lead intervals was moderated by the participants' current mood: negative affect predicted stronger patterns of attenuation, which might be interpreted as an increase in self-focus resulting from more negative mood.

  12. The Electrooculogram and a New Blink Detection Algorithm

    Science.gov (United States)

    2015-10-30

    blinks involve both reflexive (startle) blinks, which occur to protect the eye in reaction to an external impetus, and spontaneous (endogenous) blinks...burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching...0964. Report contains color. 14. ABSTRACT (Maximum 200 words) Accurate and efficient real- time cognitive workload assessment has many important

  13. Low dimensional temporal organization of spontaneous eye blinks in adults with developmental disabilities and stereotyped movement disorder.

    Science.gov (United States)

    Lee, Mei-Hua; Bodfish, James W; Lewis, Mark H; Newell, Karl M

    2010-01-01

    This study investigated the mean rate and time-dependent sequential organization of spontaneous eye blinks in adults with intellectual and developmental disability (IDD) and individuals from this group who were additionally categorized with stereotypic movement disorder (IDD+SMD). The mean blink rate was lower in the IDD+SMD group than the IDD group and both of these groups had a lower blink rate than a contrast group of healthy adults. In the IDD group the n to n+1 sequential organization over time of the eye-blink durations showed a stronger compensatory organization than the contrast group suggesting decreased complexity/dimensionality of eye-blink behavior. Very low blink rate (and thus insufficient time series data) precluded analysis of time-dependent sequential properties in the IDD+SMD group. These findings support the hypothesis that both IDD and SMD are associated with a reduction in the dimension and adaptability of movement behavior and that this may serve as a risk factor for the expression of abnormal movements.

  14. The anti-fatigue driving system design based on the eye blink detect

    Science.gov (United States)

    Yang, Shuyu; Song, Xin; Zhang, Li; Yu, Jie

    2017-01-01

    Traffic accident is one of the severe social problems in the world, but the appraisal and prevention of the fatigue driving is still a difficult problem that can not be solved. This paper is to study the results of fatigue driving and the existing antifatigue driving products, collecting brain wave with the TGAM (ThinkGear AM) Brain Wave Sensor Chip. We analyze the collected waveform based on eye blink detect algorithm to work out current situation of the driver. According to the analysis results, Sound Module and controllable speed car will make a series of feedback. Finally, an effective Anti- Fatigue Driving System is designed based on all above.

  15. Eye blink artifact rejection in single-channel electroencephalographic signals by complete ensemble empirical mode decomposition and independent component analysis.

    Science.gov (United States)

    Kanoga, Suguru; Mitsukura, Yasue

    2015-01-01

    To study an eye blink artifact rejection scheme from single-channel electroencephalographic (EEG) signals has been now a major challenge in the field of EEG signal processing. High removal performance is still needed to more strictly investigate pattern of EEG features. This paper proposes a new eye blink artifact rejection scheme from single-channel EEG signals by combining complete ensemble empirical mode decomposition (CEEMD) and independent component analysis (ICA). We compare the separation performance of our proposed scheme with existing schemes (wavelet-ICA, EMD-ICA, and EEMD-ICA) though real-life data by using signal-to-noise ratio. As a result, CEEMD-ICA showed high performance (11.86 dB) than all other schemes (10.78, 10.59, and 11.30 dB) in the ability of eye blink artifact removal.

  16. Hybrid EEG—Eye Tracker: Automatic Identification and Removal of Eye Movement and Blink Artifacts from Electroencephalographic Signal

    Directory of Open Access Journals (Sweden)

    Malik M. Naeem Mannan

    2016-02-01

    Full Text Available Contamination of eye movement and blink artifacts in Electroencephalogram (EEG recording makes the analysis of EEG data more difficult and could result in mislead findings. Efficient removal of these artifacts from EEG data is an essential step in improving classification accuracy to develop the brain-computer interface (BCI. In this paper, we proposed an automatic framework based on independent component analysis (ICA and system identification to identify and remove ocular artifacts from EEG data by using hybrid EEG and eye tracker system. The performance of the proposed algorithm is illustrated using experimental and standard EEG datasets. The proposed algorithm not only removes the ocular artifacts from artifactual zone but also preserves the neuronal activity related EEG signals in non-artifactual zone. The comparison with the two state-of-the-art techniques namely ADJUST based ICA and REGICA reveals the significant improved performance of the proposed algorithm for removing eye movement and blink artifacts from EEG data. Additionally, results demonstrate that the proposed algorithm can achieve lower relative error and higher mutual information values between corrected EEG and artifact-free EEG data.

  17. Hybrid EEG--Eye Tracker: Automatic Identification and Removal of Eye Movement and Blink Artifacts from Electroencephalographic Signal.

    Science.gov (United States)

    Mannan, Malik M Naeem; Kim, Shinjung; Jeong, Myung Yung; Kamran, M Ahmad

    2016-02-19

    Contamination of eye movement and blink artifacts in Electroencephalogram (EEG) recording makes the analysis of EEG data more difficult and could result in mislead findings. Efficient removal of these artifacts from EEG data is an essential step in improving classification accuracy to develop the brain-computer interface (BCI). In this paper, we proposed an automatic framework based on independent component analysis (ICA) and system identification to identify and remove ocular artifacts from EEG data by using hybrid EEG and eye tracker system. The performance of the proposed algorithm is illustrated using experimental and standard EEG datasets. The proposed algorithm not only removes the ocular artifacts from artifactual zone but also preserves the neuronal activity related EEG signals in non-artifactual zone. The comparison with the two state-of-the-art techniques namely ADJUST based ICA and REGICA reveals the significant improved performance of the proposed algorithm for removing eye movement and blink artifacts from EEG data. Additionally, results demonstrate that the proposed algorithm can achieve lower relative error and higher mutual information values between corrected EEG and artifact-free EEG data.

  18. Impact of air temperature, relative humidity, air movement and pollution on eye blinking

    DEFF Research Database (Denmark)

    Melikov, Arsen Krikor; Lyubenova, Velina S.; Skwarczynski, Mariusz;

    2011-01-01

    The effect of indoor air temperature, relative humidity, velocity and pollution on occupants’ eye blink frequency (BF) was examined. In total sixty subjects participated in eight 4 hour experiments without and with facially applied air movement under individual control of the subjects. Air movement...... of either polluted room air supplied isothermally or clean and cool air was used. Eye blinking video record for the last 15 min of each exposure were analysed. The increase of the room air temperature and relative humidity from 23 °C and 40% to 26 °C and 70% or to 28 °C and 70% decreased the BF....... At temperature of 26 °C and relative humidity of 70% facially applied flow of polluted room air didn’t have significant impact on BF in comparison without air movement. The increase of BF due to decrease of temperature and humidity and increase of velocity may be compensated due to the increase in air cleanness....

  19. Decreased spontaneous eye blink rates in chronic cannabis users: evidence for striatal cannabinoid-dopamine interactions.

    Directory of Open Access Journals (Sweden)

    Mikael A Kowal

    Full Text Available Chronic cannabis use has been shown to block long-term depression of GABA-glutamate synapses in the striatum, which is likely to reduce the extent to which endogenous cannabinoids modulate GABA- and glutamate-related neuronal activity. The current study aimed at investigating the effect of this process on striatal dopamine levels by studying the spontaneous eye blink rate (EBR, a clinical marker of dopamine level in the striatum. 25 adult regular cannabis users and 25 non-user controls matched for age, gender, race, and IQ were compared. Results show a significant reduction in EBR in chronic users as compared to non-users, suggesting an indirect detrimental effect of chronic cannabis use on striatal dopaminergic functioning. Additionally, EBR correlated negatively with years of cannabis exposure, monthly peak cannabis consumption, and lifetime cannabis consumption, pointing to a relationship between the degree of impairment of striatal dopaminergic transmission and cannabis consumption history.

  20. Neural Control of Voluntary Eye Closure: A Case Study and an fMRI Investigation of Blinking and Winking

    Directory of Open Access Journals (Sweden)

    Martijn G. van Koningsbruggen

    2012-01-01

    Full Text Available The current paper describes a rare case of a patient who suffered from unilateral apraxia of eye closure as a result of a bilateral stroke. Interestingly, the patient’s ability to voluntarily close both eyelids (i.e. blinking was not affected, indicating that different neural mechanisms control each type of eye closure. The stroke caused damage to a large part of the right frontal cortex, including the motor cortex, pre-motor cortex and the frontal eye field (FEF. The lesion in the left hemisphere was restricted to the FEF. In order to further study the neural mechanisms of eye closure, we conducted an fMRI study in a group of neurological healthy subjects. We found that all areas of the oculomotor cortex were activated by both left and right winking, including the FEF, supplementary eye field (SEF, and posterior parietal cortex (PPC. Blinking activated FEF and SEF, but not PPC. Both FEF and PPC were significantly more active during winking than blinking. Together, these results provide evidence for a critical role of the FEF in voluntary unilateral eye closure.

  1. Removal of eye blink artifacts in wireless EEG sensor networks using reduced-bandwidth canonical correlation analysis

    Science.gov (United States)

    Somers, Ben; Bertrand, Alexander

    2016-12-01

    Objective. Chronic, 24/7 EEG monitoring requires the use of highly miniaturized EEG modules, which only measure a few EEG channels over a small area. For improved spatial coverage, a wireless EEG sensor network (WESN) can be deployed, consisting of multiple EEG modules, which interact through short-distance wireless communication. In this paper, we aim to remove eye blink artifacts in each EEG channel of a WESN by optimally exploiting the correlation between EEG signals from different modules, under stringent communication bandwidth constraints. Approach. We apply a distributed canonical correlation analysis (CCA-)based algorithm, in which each module only transmits an optimal linear combination of its local EEG channels to the other modules. The method is validated on both synthetic and real EEG data sets, with emulated wireless transmissions. Main results. While strongly reducing the amount of data that is shared between nodes, we demonstrate that the algorithm achieves the same eye blink artifact removal performance as the equivalent centralized CCA algorithm, which is at least as good as other state-of-the-art multi-channel algorithms that require a transmission of all channels. Significance. Due to their potential for extreme miniaturization, WESNs are viewed as an enabling technology for chronic EEG monitoring. However, multi-channel analysis is hampered in WESNs due to the high energy cost for wireless communication. This paper shows that multi-channel eye blink artifact removal is possible with a significantly reduced wireless communication between EEG modules.

  2. Robotic Wheelchair Using Eye Blink Sensors and Accelerometer Provided with Home Appliance Control

    Directory of Open Access Journals (Sweden)

    Colleen Nelson

    2014-05-01

    Full Text Available According to a new report prepared jointly by the World Health Organization and the World Bank, 15 percent of the world‘s population is disabled. The use of powered wheelchairs with high navigational intelligence is one of the great steps towards the integration of severely physically disabled and mentally handicapped people. Driving a wheelchair is a tedious task for severely handicapped persons, unless they use the tongue to control the joystick. Simultaneously blind and paraplegic people deal with two problems, which creates uneasy situation for them, i.e locomotion and localization. Different systems are being developed to overcome the problems described above, allowing the end-user to perform safe movements and accomplish some daily life important tasks. Our Robotic wheelchair uses eye blink and head tilt movement to steer the wheelchair. In addition, we can give more independence to the disabled person by using the same head-tilt movement to communicate with the devices in a room for example: a fan. This communication is done using a RF transmitter and receiver. Using this, the person can control various devices easily.

  3. Effect of a light-emitting timer device on the blink rate of non-dry eye individuals and dry eye patients.

    Science.gov (United States)

    Miura, Danielle Lumi; Hazarbassanov, Rossen Mihaylov; Yamasato, Camila Karim Nakase; Bandeira e Silva, Francisco; Godinho, Cléber José; Gomes, José Álvaro Pereira

    2013-08-01

    To evaluate blink rate effects by a novel light-emitting diode (LED) timer device (PISC) on non-dry eye (DE) subjects and DE patients during a reading task on liquid crystal display (LCD) screens, in different environmental conditions. This was a case-control study that included 15 DE patients and 15 non-DE subjects as controls. Participants had their blink rates measured while they read an electronic format text. These tasks were performed in four different conditions: with and without a LED timer device in two visits, and with and without air conditioning. All participants completed the Ocular Surface Disease Index and were examined by best spectacle-corrected visual acuity exam, biomicroscopy, Schirmer test 1, fluorescein staining and break-up time and lissamine green staining (Oxford scale grading). Outcomes between reading tasks conditions were compared independently for each group and blink rate frequency was higher in tasks with LED timer device, with and without air conditioning, for the DE group (ptimer device increased blink frequency for DE and control groups. Further studies need to be carried out in order to evaluate long-term effects of this new device, as well as its assessment with different reading scenarios.

  4. Eyelid contour detection and tracking for startle research related eye-blink measurements from high-speed video records.

    Science.gov (United States)

    Bernard, Florian; Deuter, Christian Eric; Gemmar, Peter; Schachinger, Hartmut

    2013-10-01

    Using the positions of the eyelids is an effective and contact-free way for the measurement of startle induced eye-blinks, which plays an important role in human psychophysiological research. To the best of our knowledge, no methods for an efficient detection and tracking of the exact eyelid contours in image sequences captured at high-speed exist that are conveniently usable by psychophysiological researchers. In this publication a semi-automatic model-based eyelid contour detection and tracking algorithm for the analysis of high-speed video recordings from an eye tracker is presented. As a large number of images have been acquired prior to method development it was important that our technique is able to deal with images that are recorded without any special parametrisation of the eye tracker. The method entails pupil detection, specular reflection removal and makes use of dynamic model adaption. In a proof-of-concept study we could achieve a correct detection rate of 90.6%. With this approach, we provide a feasible method to accurately assess eye-blinks from high-speed video recordings.

  5. About the effect of eye blinking on drug release from pHEMA-based hydrogels: an in vitro study.

    Science.gov (United States)

    Galante, R; Paradiso, P; Moutinho, M G; Fernandes, A I; Mata, J L G; Matos, A P A; Colaço, R; Saramago, B; Serro, A P

    2015-01-01

    The development of new ophthalmic drug delivery systems capable of increasing the residence time of drugs in the eye and improve its bioavailability relatively to eyedrops has been object of intense research in recent years. Several studies have shown that drug-loaded therapeutic soft contact lenses (SCLs) constitute a promising approach, with several potential advantages as compared with collyria. The main objective of this work is to study the effect of repetitive load and friction cycles caused by the eye blinking, on the drug release from hydrogels used in SCLs which, as far as we know, was never investigated before. Two poly-2-hydroxyethylmethacrylate-based hydrogels, pHEMA-T and pHEMA-UV, were used as model materials. Levofloxaxin was chosen as model drug. The hydrogels were fully characterized in what concerns structural and physicochemical properties. pHEMA-UV revealed some superficial porosity and a lower short-range order than pHEMA-T. We observe that the load and friction cycles enhanced the drug release from pHEMA-UV hydrogels. The application of a simple mathematical model, which takes into account the drug dilution caused by the tear flow, showed that the enhancement of the drug release caused by blinking on this hydrogel may be relevant in in vivo conditions. Conversely, the more sustained drug release from pHEMA-T is not affected by load and friction cycles. The conclusion is that, depending on the physicochemical and microstructural characteristics of the hydrogels, blinking is a factor that may affect the amount of drug delivered to the eye by SCLs and should thus be considered.

  6. Blink rate, incomplete blinks and computer vision syndrome.

    Science.gov (United States)

    Portello, Joan K; Rosenfield, Mark; Chu, Christina A

    2013-05-01

    Computer vision syndrome (CVS), a highly prevalent condition, is frequently associated with dry eye disorders. Furthermore, a reduced blink rate has been observed during computer use. The present study examined whether post task ocular and visual symptoms are associated with either a decreased blink rate or a higher prevalence of incomplete blinks. An additional trial tested whether increasing the blink rate would reduce CVS symptoms. Subjects (N = 21) were required to perform a continuous 15-minute reading task on a desktop computer at a viewing distance of 50 cm. Subjects were videotaped during the task to determine their blink rate and amplitude. Immediately after the task, subjects completed a questionnaire regarding ocular symptoms experienced during the trial. In a second session, the blink rate was increased by means of an audible tone that sounded every 4 seconds, with subjects being instructed to blink on hearing the tone. The mean blink rate during the task without the audible tone was 11.6 blinks per minute (SD, 7.84). The percentage of blinks deemed incomplete for each subject ranged from 0.9 to 56.5%, with a mean of 16.1% (SD, 15.7). A significant positive correlation was observed between the total symptom score and the percentage of incomplete blinks during the task (p = 0.002). Furthermore, a significant negative correlation was noted between the blink score and symptoms (p = 0.035). Increasing the mean blink rate to 23.5 blinks per minute by means of the audible tone did not produce a significant change in the symptom score. Whereas CVS symptoms are associated with a reduced blink rate, the completeness of the blink may be equally significant. Because instructing a patient to increase his or her blink rate may be ineffective or impractical, actions to achieve complete corneal coverage during blinking may be more helpful in alleviating symptoms during computer operation.

  7. Positive priming and intentional binding: eye-blink rate predicts reward information effects on the sense of agency.

    Science.gov (United States)

    Aarts, Henk; Bijleveld, Erik; Custers, Ruud; Dogge, Myrthel; Deelder, Merel; Schutter, Dennis; Haren, Neeltje E M van

    2012-01-01

    Human society is strongly rooted in people's experiences of agency; that is, the pervasive feeling that one engages in voluntary behavior and causes one's own actions and resulting outcomes. Rewards and positive affect play an important role in the control of voluntary action. However, the role of positive reward signals in the sense of agency is poorly understood. This study examined effects of reward-related information on the sense of agency by employing the intentional binding paradigm. This paradigm measures the extent to which actions and their effects subjectively shift together across time, reflecting a crucial component of people's sense of agency. Results showed that intentional binding is stronger when participants are primed with reward-related information via brief exposure to positive pictures. Interestingly, this positive priming effect was moderated by baseline eye-blink rates (an indirect marker of striatal dopaminergic functioning); reward-related information increased intentional binding mainly for participants displaying higher baseline eye-blink rates. These findings suggest a possible role for striatal dopamine activity in the process by which reward-related information shapes the way people see themselves as agents.

  8. Combining Blink, Pupil, and Response Time Measures in a Concealed Knowledge Test

    Directory of Open Access Journals (Sweden)

    Travis eSeymour

    2013-02-01

    Full Text Available The response time (RT based Concealed Knowledge Test (CKT has been shown to accurately detect participants’ knowledge of mock-crime related information. Tests based on ocular measures such as pupil size and blink rate have sometimes resulted in poor classification, or lacked detailed classification analyses. The present study examines the fitness of multiple pupil and blink related responses in the CKT paradigm. To maximize classification efficiency, participants’ concealed knowledge was assessed using both individual test measures and combinations of test measures. Results show that individual pupil-size, pupil-slope, and pre-response blink-rate measures produce efficient classifications. Combining pupil and blink measures yielded more accuracy classifications than individual ocular measures. Although RT-based tests proved efficient, combining RT with ocular measures had little incremental benefit. It is argued that covertly assessing ocular measures during RT-based tests may guard against effective countermeasure use in applied settings. A compound classification procedure was used to categorize individual participants and yielded high hit rates and low false-alarm rates without the need for adjustments between test paradigms or subject populations. We conclude that with appropriate test paradigms and classification analyses, ocular measures may prove as effective as other indices, though additional research is needed.

  9. ADHD subjects fail to suppress eye blinks and microsaccades while anticipating visual stimuli but recover with medication.

    Science.gov (United States)

    Fried, Moshe; Tsitsiashvili, Eteri; Bonneh, Yoram S; Sterkin, Anna; Wygnanski-Jaffe, Tamara; Epstein, Tamir; Polat, Uri

    2014-08-01

    Oculomotor behavior and parameters are known to be affected by the allocation of attention and could potentially be used to investigate attention disorders. We explored the oculomotor markers of Attention-deficit/hyperactivity disorder (ADHD) that are involuntary and quantitative and that could be used to reveal the core-affected mechanisms, as well as be used for differential diagnosis. We recorded eye movements in a group of 22 ADHD-diagnosed patients with and without medication (methylphenidate) and in 22 control observers while performing the test of variables of attention (t.o.v.a.). We found that the average microsaccade and blink rates were higher in the ADHD group, especially in the time interval around stimulus onset. These rates increased monotonically over session time for both groups, but with significantly faster increments in the unmedicated ADHD group. With medication, the level and time course of the microsaccade rate were fully normalized to the control level, regardless of the time interval within trials. In contrast, the pupil diameter decreased over time within sessions and significantly increased above the control level with medication. We interpreted the suppression of microsaccades and eye blinks around the stimulus onset as reflecting a temporal anticipation mechanism for the transient allocation of attention, and their overall rates as inversely reflecting the level of arousal. We suggest that ADHD subjects fail to maintain sufficient levels of arousal during a simple and prolonged task, which limits their ability to dynamically allocate attention while anticipating visual stimuli. This impairment normalizes with medication and its oculomotor quantification could potentially be used for differential diagnosis. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Eye Blink Imitation Based on Mel Script%基于Mel Script的人眼随机眨动行为仿真研究

    Institute of Scientific and Technical Information of China (English)

    惠晓钟

    2011-01-01

    This paper discusses the method for imitating human eye random blink behavior with Maya Mel Script. The basic rules of human eye blink, eye rigging and wrapping technique in Maya, and the method of imitating eye blink with Mel script without keyframing are analyzed. The advantages and disadvantages of Blendshape and joint rigging in facial animation are discussed. The result shows that the imitation is working, and it saves the animator's time.%为说明如何用Maya Mel Script脚本语言对人眼随机眨动行为进行仿真;文章分析了人眼眨动的行为规律,说明了在Maya中对眼睛的骨骼绑定和封装技术,以及利用独立于动画时间线和关键帧编辑模式的Mel Script动画技术模拟人眼的随机眨动行为.并讨论了Blendshape技术和骨骼绑定结合Mel Script动画技术在动画效果上的优劣.结果证明基于Mel Script的人眼随机眨动行为仿真是可行的,可以节省动画制作时间.

  11. Effect of seated trunk posture on eye blink startle and subjective experience: comparing flexion, neutral upright posture, and extension of spine.

    Directory of Open Access Journals (Sweden)

    Erik Ceunen

    Full Text Available Postures are known to be able to affect emotion and motivation. Much less is known about whether (affective modulation of eye blink startle occurs following specific postures. The objective of the current study was to explore this. Participants in the present study were requested to assume three different sitting postures: with the spine flexed (slouched, neutral upright, and extended. Each posture was assumed for four minutes, and was followed by the administration of brief self-report questionnaires before proceeding to the next posture. The same series of postures and measures were repeated prior to ending the experiment. Results indicate that, relative to the other postures, the extended sitting posture was associated with an increased startle, was more unpleasant, arousing, had smaller levels of dominance, induced more discomfort, and was perceived as more difficult. The upright and flexed sitting postures differed in the level of self-reported positive affect, but not in eye blink startle amplitudes.

  12. Effect of seated trunk posture on eye blink startle and subjective experience: comparing flexion, neutral upright posture, and extension of spine.

    Science.gov (United States)

    Ceunen, Erik; Zaman, Jonas; Vlaeyen, Johan W S; Dankaerts, Wim; Van Diest, Ilse

    2014-01-01

    Postures are known to be able to affect emotion and motivation. Much less is known about whether (affective) modulation of eye blink startle occurs following specific postures. The objective of the current study was to explore this. Participants in the present study were requested to assume three different sitting postures: with the spine flexed (slouched), neutral upright, and extended. Each posture was assumed for four minutes, and was followed by the administration of brief self-report questionnaires before proceeding to the next posture. The same series of postures and measures were repeated prior to ending the experiment. Results indicate that, relative to the other postures, the extended sitting posture was associated with an increased startle, was more unpleasant, arousing, had smaller levels of dominance, induced more discomfort, and was perceived as more difficult. The upright and flexed sitting postures differed in the level of self-reported positive affect, but not in eye blink startle amplitudes.

  13. Blink lagophthalmos and dry eye keratopathy in patients with non-facial palsy: clinical features and management with upper eyelid loading.

    Science.gov (United States)

    Patel, Vikesh; Daya, Sheraz M; Lake, Damian; Malhotra, Raman

    2011-01-01

    To evaluate the outcome of using upper eyelid gold weight implantation for patients with non-paralytic lagophthalmos on blink (LOB) only. We highlight the features of incomplete blink and reduced blink rate in patients with non-facial palsy as an exacerbating factor in dry eye keratopathy. Retrospective, noncomparative case series. Twelve patients (21 procedures) who underwent upper eyelid gold weight implantation for non-paralytic LOB only. Retrospective case note review of patients who underwent upper eyelid loading for non-paralytic LOB only over a 5-year period at a single institution. Improvement in LOB, gentle and forced closure, increased frequency of blinking (FOB), degree of corneal staining, incidence of epithelial defects or corneal ulcer, improvement in vision, and subjective improvement in ocular discomfort. Twenty-one procedures in 12 patients. Nine patients underwent bilateral surgery. Mean age was 56 (range, 8-80) years. Median postoperative follow-up was 15 months, and mean follow-up was 20.38 ± 16.61 (6-58) months. Eleven of 12 patients had an improvement in LOB and increased FOB, resulting in improvement of keratopathy and reduced ocular discomfort. One patient developed superior corneal thinning and descemetocele, requiring removal of the gold weight; 1 patient required ptosis surgery; and 1 patient developed a gold allergy and underwent platinum chain exchange. We highlight the need to consider incomplete blink and reduced FOB as exacerbating factors for corneal-related disorders, including dry eye. Upper eyelid loading with gold weight implantation is a useful and predictive method of improving exposure-related keratopathy due to LOB in the absence of facial palsy. Copyright © 2011 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

  14. Aging of the trigeminal blink system.

    Science.gov (United States)

    Peshori, K R; Schicatano, E J; Gopalaswamy, R; Sahay, E; Evinger, C

    2001-02-01

    This study characterizes trigeminal blinks in normal human subjects between 20 and 80 years of age, 60-year-old Parkinson's disease patients, and young and old guinea pigs. In normal humans over 60 years of age, lid-closing duration, and the excitability and latency of the trigeminal reflex blink increase significantly relative to younger subjects. Aged guinea pigs appear to display similar increases in reflex blink duration and latency. Reflex blink amplitude, however, does not change consistently with age. For subjects less than 70 years of age, a unilateral trigeminal stimulus evokes a 37% larger blink in the eyelid ipsilateral to the stimulus than in the contralateral eyelid, but 70-year-olds exhibit blinks of equal amplitude. In all cases, blink duration is identical for the two eyelids. If normal, age-related loss of dopamine neurons explains these trigeminal blink modifications, then Parkinson's disease should exaggerate age-related changes in these blink parameters. Preliminary data show that Parkinson's disease increases blink duration and excitability relative to age-matched control subjects. Thus, it seems likely that normal, age-related loss of dopamine neurons accounts for increases in trigeminal blink excitability and duration. A previously uncharacterized type of trigeminally evoked blink appears after age 40 in humans and in aged guinea pigs. In subjects less than 40 years old, a single trigeminal stimulus elicits a single reflex blink. In subjects over age 40, however, a single stimulus frequently evokes a reflex blink and additional blinks that occur at a fixed interval relative to the preceding blink. These "blink oscillations" may arise from oscillatory processes within trigeminal reflex blink circuits. The presence of exaggerated blink oscillations in subjects with dry eye and benign essential blepharospasm suggests that an alteration of blink oscillation mechanisms plays a critical role in these disorders.

  15. Effect of Seated Trunk Posture on Eye Blink Startle and Subjective Experience: Comparing Flexion, Neutral Upright Posture, and Extension of Spine

    OpenAIRE

    2014-01-01

    Postures are known to be able to affect emotion and motivation. Much less is known about whether (affective) modulation of eye blink startle occurs following specific postures. The objective of the current study was to explore this. Participants in the present study were requested to assume three different sitting postures: with the spine flexed (slouched), neutral upright, and extended. Each posture was assumed for four minutes, and was followed by the administration of brief self-report que...

  16. Dopamine and executive function: Increased spontaneous eye blink rates correlate with better set-shifting and inhibition, but poorer updating.

    Science.gov (United States)

    Zhang, Ting; Mou, Di; Wang, Cuicui; Tan, Fengping; Jiang, Yan; Lijun, Zheng; Li, Hong

    2015-06-01

    The central dopamine system (DA) has a significant role in the executive function (EF). The spontaneous eye blink rate (EBR) is an effective clinical and non-invasive measure, which is strongly related to the activity of the central dopaminergic system. Previous studies show significant relationships between the two main dimensions of EF (i.e., shifting and inhibition) and the central DA system as measured by EBR. However, most of these studies involve only one EF task for shifting or inhibition; whether or not these relationships are replicated by other EF tasks remains unclear. Besides, the relationship between EBR and another important EF dimension-updating-also remains unknown. The present study examined the correlation between EBR and several EF tasks that captured all the three EF dimensions: shifting, inhibition, and updating. A total of 61 healthy participants were subjected to EBR testing and EF tasks. Results showed that EBR had a different relationship with each of the three tested EF dimensions. An increase in EBR levels was related to an increase in accuracy in shifting and inhibition tasks, a decrease in shifting and inhibition cost, and a decrease in accuracy in updating tasks. These results imply that the role of the central DA system in shifting and inhibition differs from its role in updating. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. The effect on human eye blink frequency of exposure to limonene oxidation products and methacrolein

    DEFF Research Database (Denmark)

    Nøjgaard, Jacob Klenø; Christensen, Karl Bang; Wolkoff, Peder

    2005-01-01

    to LOPs and methacrolein compared to the baseline of clean air, and the findings coincided with weak eye irritation symptoms. Lowest observed effect levels were 286 ppb methacrolein and a 10-min-old LOPs mixture of initially 92 ppb limonene and 101 ppb ozone (O3), which increased the BF comparably by 18......% (p=0.001) and 17% (p=0.003), respectively. The increase in BF was smaller, although not significantly different, during exposure to LOPs at 50% RH to 20% RH in mixtures prepared from ca. 350 ppb limonene and 300 ppb O3. LOPs may cause trigeminal stimulation and possibly eye irritation at O3...

  18. Did Lavoisier Blink?

    Science.gov (United States)

    Jensen, William B.

    2004-01-01

    A question and answer session on whether Lavoisier made an agreement with the French mathematician, Comte Joseph-Louis Lagrange shortly before being beheaded that he would blink his eyes if he retained consciousness after being beheaded and that he was executed because of his revolutionary scientific views is described. The circumstances…

  19. 基于眨眼修正卡尔曼滤波的人眼跟踪研究%Research on Eye Tracking Based on Blinking Correction Kalman Filter

    Institute of Scientific and Technical Information of China (English)

    张琳琳; 蒋敏; 唐晓微

    2012-01-01

    Eye movement is easily influenced by head posture change, external simulation interference and actual light conditions. The existing algorithms have low accuracy and robustness. An eye tracking algorithm based on blinking correction Kalman filter is proposed. Eye region of face image is detected using vertical and horizontal integral projection function. It uses the color entropy of eye region to eliminate uncorrelated factors, precisely locates the position of pupil. The eye region is tracked in real time by Kalman filter, and eye blink detection is combined to revise eye tracking. Experimental results show that the algorithm has high accuracy and good real-time.%眼睛运动容易受到头部姿势变化、外界仿真干扰、实际光照条件等影响,已有眼部跟踪算法的准确率、鲁棒性较低.为此,提出一种基于眨眼修正卡尔曼滤波的人眼跟踪算法.采用垂直积分投影函数和水平积分投影函数得到人脸图像的眼睛区域,运用眼睛区域的颜色熵消除不相关因素,定位出瞳孔的位置,用卡尔曼滤波进行实时眼部跟踪,结合眨眼检测实时修正跟踪结果.实验结果表明,该算法准确率较高,实时性较好.

  20. In the blink of an eye: head mounted displays development within BAE Systems

    Science.gov (United States)

    Cameron, Alex

    2015-05-01

    There has been an explosion of interest in head worn displays in recent years, particularly for consumer applications with an attendant ramping up of investment into key enabling technologies to provide what is essence a mobile computer display. However, head mounted system have been around for over 40 years and today's consumer products are building on a legacy of knowledge and technology created by companies such as BAE Systems who have been designing and fielding helmet mounted displays (HMD) for a wide range of specialist applications. Although the dominant application area has been military aviation, solutions have been fielded for solider, ground vehicle, simulation, medical, racing car and even subsea navigation applications. What sets these HMDs apart is that they provide the user with accurate conformal information embedded in the users real world view where the information presented is intuitive and easy to use because it overlays the real world and enables them to stay head up, eyes out, - improving their effectiveness, reducing workload and improving safety. Such systems are an enabling technology in the provision of enhanced Situation Awareness (SA) and reducing user workload in high intensity situations. These capabilities are finding much wider application in new types of compact man mounted audio/visual products enabled by the emergence of new families of micro displays, novel optical concepts and ultra-compact low power processing solutions. This paper therefore provides a personal summary of BAE Systems 40 year's journey in developing and fielding Head Mounted systems, their applications.

  1. Blinking and the Brain: Pathways and Pathology

    NARCIS (Netherlands)

    A.E. Smit (Albertine Eline)

    2009-01-01

    textabstractA blink is a rapid bilateral eyelid closure and co-occurring eye movement. The eyes rotate down towards the tip of the nose and back up again. Seemingly, this generally unnoticed often repeated action is not very spectacular. However, if not for the occasional blink we would all be blind

  2. The three responses of the blink reflex in adult and juvenile migraine.

    Science.gov (United States)

    de Tommaso, M; Guido, M; Libro, G; Sciruicchio, V; Puca, F

    2000-06-01

    Recent theories about migraine pathogenesis have emphasized the role of the trigeminal system in the pathogenesis of migraine attacks (Moskowitz, 1997). The blink reflex (BR) could be a suitable method to evaluate the trigeminal system in migraine, as it is generally elicited by stimulation of the trigeminal ophthalmic division (Kimura et al., 1967), involved in migraine attacks. Sixty one adult and 15 juvenile migraine without aura subjects were selected, in order to evaluate the BR features, including the subjective perceptive and pain thresholds and the R1, R2 and R3 components intensity thresholds and amplitudes. The electrophysiological procedure was carried out during the pain free phase. The findings were compared with those of 28 healthy controls, 18 adults and 10 children. In both adult and juvenile migraine sufferers an early appearance of the R3 response at almost the R2 threshold was observed in comparison with age-matched controls. Unfortunately, the anatomic and physiologic organization of the R3 component is uncertain: its early onset could suggest a dysfunction of the inhibitory control system on the trigeminal networks, which may predispose to migraine attacks.

  3. About the effect of eye blinking on drug release from pHEMA-based hydrogels: an in vitro study

    OpenAIRE

    Galante, Raquel; Paradiso, Patrizia; Moutinho, Maria Guilhermina; Fernandes, Ana Isabel; Mata, José; Matos, António; Colaço, Rogério; Saramago, Benilde; Serro, Ana Paula

    2015-01-01

    "The development of new ophthalmic drug delivery systems capable of increasing the residence time of drugs in the eye and improve its bioavailability relatively to eyedrops has been object of intense research in recent years. Several studies have shown that drug loaded therapeutic soft contact lenses (SCLs) constitute a promising approach, with several potential advantages as compared with collyria. The main objective of this work is to study the effect of repetitive load and f...

  4. Blinking supervision in a working environment

    Science.gov (United States)

    Morcego, Bernardo; Argilés, Marc; Cabrerizo, Marc; Cardona, Genís; Pérez, Ramon; Pérez-Cabré, Elisabet; Gispets, Joan

    2016-02-01

    The health of the ocular surface requires blinks of the eye to be frequent in order to provide moisture and to renew the tear film. However, blinking frequency has been shown to decrease in certain conditions such as when subjects are conducting tasks with high cognitive and visual demands. These conditions are becoming more common as people work or spend their leisure time in front of video display terminals. Supervision of blinking frequency in such environments is possible, thanks to the availability of computer-integrated cameras. Therefore, the aim of the present study is to develop an algorithm for the detection of eye blinks and to test it, in a number of videos captured, while subjects are conducting a variety of tasks in front of the computer. The sensitivity of the algorithm for blink detection was found to be of 87.54% (range 30% to 100%), with a mean false-positive rate of 0.19% (range 0% to 1.7%), depending on the illumination conditions during which the image was captured and other computer-user spatial configurations. The current automatic process is based on a partly modified pre-existing eye detection and image processing algorithms and consists of four stages that are aimed at eye detection, eye tracking, iris detection and segmentation, and iris height/width ratio assessment.

  5. A Fast, Robust, Automatic Blink Detector

    Directory of Open Access Journals (Sweden)

    Javad Sayahzadeh

    2014-11-01

    Full Text Available Introduction “Blink” is defined as closing and opening of the eyes in a small duration of time. In this study, we aimed to introduce a fast, robust, vision-based approach for blink detection. Materials and Methods This approach consists of two steps. In the first step, the subject’s face is localized every second and with the first blink, the system detects the eye’s location and creates an open-eye template image. In the second step, the eye is tracked, using sum of squared differences (SSD. This system can classify the state of the eyes as open, closed, or lost, using the SSD-based classifier. If the eyes are closed as in usual blinking, the blink will be detected. To classify eyes as closed or open, two adaptive thresholds were proposed; therefore, factors such as the subject’s distance from the camera or environment illumination did not affect the system performance. In addition, in order to improve system performance, a new feature, called "peak-to-neighbors ratio", was proposed. Results The accuracy of this system was 96.03%, based on the evaluation on Zhejiang University (ZJU dataset, and 98.59% in our own dataset. Conclusion The present system was faster than other systems, which use normalized correlation coefficient (NCC for eye tracking, since time complexity of SSD is lower than that of NCC. The achieved processing rate for ZJU dataset was 35 fps.

  6. Results of Investigations on the Blink Reflex as a Protective Means against Laser and LED Radiation: A Description Based on Fundamental Psychophysical Laws

    Energy Technology Data Exchange (ETDEWEB)

    Hans-Dieter Reidenbach [Cologne University of Applied Sciences Research Laboratory on Medical Technology/HLT Betzdorfer Str. 2, 50679 Koeln (Germany)

    2006-07-01

    2,650 volunteers have been investigated in blink-reflex studies with various test equipment, where a laser beam or a single element L.E.D. or an array have been used to irradiate the human eye in order to initiate a physiological reaction. In addition 1,196 volunteers took part in aversion response studies. 491 persons out of 2,650, i.e., 18.53 %, showed a blink reflex or lid closure, upon exposure to irradiation from a laser or an L.E.D.. Only 6.19 %, i. e., 74 out of 1,196 volunteers, showed other aversion responses, like gross eye or head movements. The different parameters which are mainly responsible for the respective results concerning the blink reflex will be dealt with and explained, as they have been achieved up to now. In addition some experimentally verified dependencies on fundamental psychophysical laws will be described. Besides the statement that the blink reflex should not be used as a sufficient physiological protective means it can be generally stated that in order to ensure their safety, in spite of the missing blink-reflex and other aversion responses, users of low-power lasers should be instructed to perform active protective reactions, e.g., to close the eyes voluntarily and simultaneously move the head away from the beam in the case of an unintentional exposure or intrabeam viewing. (author)

  7. Human Response to Ductless Personalised Ventilation: Impact of Air Movement, Temperature and Cleanness on Eye Symptoms

    DEFF Research Database (Denmark)

    Dalewski, Mariusz; Fillon, Maelys; Bivolarova, Maria;

    2013-01-01

    The performance of ductless personalized ventilation (DPV) in conjunction with displacement ventilation (DV) was studied in relation to peoples’ health, comfort and performance. This paper presents results on the impact of room air temperature, using of DPV and local air filtration on eye blink...... rate and tear film quality. In a test room with DV and six workstations 30 human subjects were exposed for four hours to each of the following 5 experimental conditions: 23 °C and DV only, 23 °C and DPV with air filter, 29 °C and DV only, 29 °C and DPV, and 29 °C and DPV with air filter. At warm...... environment facially applied individually controlled air movement of room air, with or without local filtering, did not have significant impact on eye blink frequency and tear film quality. The local air movement and air cleaning resulted in increased eye blinking frequency and improvement of tear film...

  8. Automatic and Direct Identification of Blink Components from Scalp EEG

    Directory of Open Access Journals (Sweden)

    Guojun Dai

    2013-08-01

    Full Text Available Eye blink is an important and inevitable artifact during scalp electroencephalogram (EEG recording. The main problem in EEG signal processing is how to identify eye blink components automatically with independent component analysis (ICA. Taking into account the fact that the eye blink as an external source has a higher sum of correlation with frontal EEG channels than all other sources due to both its location and significant amplitude, in this paper, we proposed a method based on correlation index and the feature of power distribution to automatically detect eye blink components. Furthermore, we prove mathematically that the correlation between independent components and scalp EEG channels can be translating directly from the mixing matrix of ICA. This helps to simplify calculations and understand the implications of the correlation. The proposed method doesn’t need to select a template or thresholds in advance, and it works without simultaneously recording an electrooculography (EOG reference. The experimental results demonstrate that the proposed method can automatically recognize eye blink components with a high accuracy on entire datasets from 15 subjects.

  9. Automatic and direct identification of blink components from scalp EEG.

    Science.gov (United States)

    Kong, Wanzeng; Zhou, Zhanpeng; Hu, Sanqing; Zhang, Jianhai; Babiloni, Fabio; Dai, Guojun

    2013-08-16

    Eye blink is an important and inevitable artifact during scalp electroencephalogram (EEG) recording. The main problem in EEG signal processing is how to identify eye blink components automatically with independent component analysis (ICA). Taking into account the fact that the eye blink as an external source has a higher sum of correlation with frontal EEG channels than all other sources due to both its location and significant amplitude, in this paper, we proposed a method based on correlation index and the feature of power distribution to automatically detect eye blink components. Furthermore, we prove mathematically that the correlation between independent components and scalp EEG channels can be translating directly from the mixing matrix of ICA. This helps to simplify calculations and understand the implications of the correlation. The proposed method doesn't need to select a template or thresholds in advance, and it works without simultaneously recording an electrooculography (EOG) reference. The experimental results demonstrate that the proposed method can automatically recognize eye blink components with a high accuracy on entire datasets from 15 subjects.

  10. What Is Dry Eye?

    Medline Plus

    Full Text Available ... is also when your eyes do not make the right type of tears. How do tears work? ... you blink, a film of tears spreads over the eye. This keeps the eye’s surface smooth and ...

  11. Blink the power of thinking without thinking

    CERN Document Server

    Gladwell, Malcolm

    2005-01-01

    In his landmark bestseller The Tipping Point, Malcolm Gladwell redefined how we understand the world around us. Now, in Blink, he revolutionizes the way we understand the world within. Blink is a book about how we think without thinking, about choices that seem to be made in an instant-in the blink of an eye-that actually aren't as simple as they seem. Why are some people brilliant decision makers, while others are consistently inept? Why do some people follow their instincts and win, while others end up stumbling into error? How do our brains really work-in the office, in the classroom, in the kitchen, and in the bedroom? And why are the best decisions often those that are impossible to explain to others?In Blink we meet the psychologist who has learned to predict whether a marriage will last, based on a few minutes of observing a couple; the tennis coach who knows when a player will double-fault before the racket even makes contact with the ball; the antiquities experts who recognize a fake at a glance. Her...

  12. Infrared-based blink-detecting glasses for facial pacing: toward a bionic blink.

    Science.gov (United States)

    Frigerio, Alice; Hadlock, Tessa A; Murray, Elizabeth H; Heaton, James T

    2014-01-01

    IMPORTANCE Facial paralysis remains one of the most challenging conditions to effectively manage, often causing life-altering deficits in both function and appearance. Facial rehabilitation via pacing and robotic technology has great yet unmet potential. A critical first step toward reanimating symmetrical facial movement in cases of unilateral paralysis is the detection of healthy movement to use as a trigger for stimulated movement. OBJECTIVE To test a blink detection system that can be attached to standard eyeglasses and used as part of a closed-loop facial pacing system. DESIGN, SETTING, AND PARTICIPANTS Standard safety glasses were equipped with an infrared (IR) emitter-detector unit, oriented horizontally across the palpebral fissure, creating a monitored IR beam that became interrupted when the eyelids closed, and were tested in 24 healthy volunteers from a tertiary care facial nerve center community. MAIN OUTCOMES AND MEASURES Video-quantified blinking was compared with both IR sensor signal magnitude and rate of change in healthy participants with their gaze in repose, while they shifted their gaze from central to far-peripheral positions, and during the production of particular facial expressions. RESULTS Blink detection based on signal magnitude achieved 100% sensitivity in forward gaze but generated false detections on downward gaze. Calculations of peak rate of signal change (first derivative) typically distinguished blinks from gaze-related eyelid movements. During forward gaze, 87% of detected blink events were true positives, 11% were false positives, and 2% were false negatives. Of the 11% false positives, 6% were associated with partial eyelid closures. During gaze changes, false blink detection occurred 6% of the time during lateral eye movements, 10% of the time during upward movements, 47% of the time during downward movements, and 6% of the time for movements from an upward or downward gaze back to the primary gaze. Facial expressions

  13. Different relationships between central dopamine system and sub-processes of inhibition: Spontaneous eye blink rate relates with N2 but not P3 in a Go/Nogo task.

    Science.gov (United States)

    Zhang, Ting; Wang, Cuicui; Tan, Fengping; Mou, Di; Zheng, Lijun; Chen, Antao

    2016-06-01

    Clinical studies show that dysfunction of the dopamine (DA) system could differently modulate N2 and P3 components in a Go/Nogo task, a classical inhibition task. However, results of previous clinical studies cannot be arbitrarily generalized to healthy adults. Thus, the present exploratory study aimed to investigate whether there are significant and variable relationships between individual differences of the DA system in normal healthy persons and N2- and P3-related sub-processes of inhibition in a Go/Nogo task. DA function was measured by spontaneous eye blink rate (EBR), which is an effective clinical and non-invasive measure and strongly related to the activity of the central dopaminergic system. A total of 28 young adults participated in this experiment. Results showed that Nogo-N2 and Nogo-P3 of all participants were larger than Go-N2 and Go-P3, while Nogo-N2 and Nogo-P3 were significantly related with Nogo-accuracy. Moreover, it was shown that higher EBRs were significantly correlated with larger and more negative N2 amplitudes under Go- and Nogo-conditions; however, there were no significant correlations between participants' EBRs and N2 latencies, and between EBRs and average amplitudes of P3 under the two conditions. Based on these results, we concluded that the central DA system was associated with the N2-related conflict monitoring rather than P3-related sub-process of inhibition.

  14. Revisiting the eye opening response of the Glasgow Coma Scale

    Directory of Open Access Journals (Sweden)

    Taopheeq Bamidele Rabiu

    2011-01-01

    Full Text Available The Glasgow Coma Scale (GCS, introduced by Teasdale and Jenneth in 1974, has received tremendous acclaim from clinicians and has been extensively used in clinical practice for the evaluation of the level of consciousness. The author notes that some traumatic brain injury patients close eyes in response to painful stimuli as opposed to the eye opening response to pain of the GCS. A revision of the eye opening response subsection of the GCS is suggested.

  15. Design of virtual keyboard using blink control method for the severely disabled.

    Science.gov (United States)

    Yang, Shih-Wei; Lin, Chern-Sheng; Lin, Shir-Kuan; Lee, Chi-Hung

    2013-08-01

    In this paper, a human-machine interface with the concept of "blink control" is proposed. The human-machine interface is applied to an assistive device, namely "blink scanning keyboard", which is designed specifically for the severely physical disabled and people suffering from motor neuron diseases or severe cerebral palsy. The pseudo electromyography (EMG) signal of blinking eyes could be acquired by wearing a Bluetooth headset with one sensor on the forehead and the other three on the left ear of the user. Through a conscious blink, a clear and immediate variation will be formed in the pseudo EMG signal from the users' forehead. The occurrence of this variation in pseudo EMG signal could be detected and filtered by the algorithms proposed in this paper, acting like a trigger to activate the functions integrated in the scanning keyboard. The severely physical and visual disabled then can operate the proposed design by simply blinking their eyes, thus communicating with outside world.

  16. Business Analytics in (a) Blink

    NARCIS (Netherlands)

    R. Barber; P. Bendel; M. Czech; O. Draese; F. Ho; N. Hrle; S. Idreos (Stratos); M Kim; O Koeth; J. Lee (Jae-Gil); T. Tim Li (Tianchao); G. Lohman; K. Morfonios; R. Mueller (René); K Murthy; I. Pandis; L. Qiao; V. Raman (Vijayshankar); R. Sidle; K Stolze; S. Szabo

    2012-01-01

    textabstractThe Blink project’s ambitious goal is to answer all Business Intelligence (BI) queries in mere seconds, regardless of the database size, with an extremely low total cost of ownership. Blink is a new DBMS aimed primarily at read-mostly BI query processing that exploits scale-out of

  17. Business Analytics in (a) Blink

    NARCIS (Netherlands)

    Barber, R.; Bendel, P.; Czech, M.; Draese, O.; Ho, F.; Hrle, N.; Idreos, S.; Kim, M; Koeth, O; Lee, J.; Tim Li, T.; Lohman, G.; Morfonios, K.; Mueller, R.; Murthy, K; Pandis, I.; Qiao, L.; Raman, V.; Sidle, R.; Stolze, K; Szabo, S.

    2012-01-01

    The Blink project’s ambitious goal is to answer all Business Intelligence (BI) queries in mere seconds, regardless of the database size, with an extremely low total cost of ownership. Blink is a new DBMS aimed primarily at read-mostly BI query processing that exploits scale-out of commodity multi-co

  18. What Is Dry Eye?

    Medline Plus

    Full Text Available ... How do tears work? When you blink, a film of tears spreads over the eye. This keeps the eye’s surface smooth and clear. The tear film is important for good vision. The tear film ...

  19. No evidence for early modulation of evoked responses in primary visual cortex to irrelevant probe stimuli presented during the attentional blink.

    Directory of Open Access Journals (Sweden)

    Oscar Jacoby

    Full Text Available BACKGROUND: During rapid serial visual presentation (RSVP, observers often miss the second of two targets if it appears within 500 ms of the first. This phenomenon, called the attentional blink (AB, is widely held to reflect a bottleneck in the processing of rapidly sequential stimuli that arises after initial sensory registration is complete (i.e., at a relatively late, post-perceptual stage of processing. Contrary to this view, recent fMRI studies have found that activity in the primary visual area (V1, which represents the earliest cortical stage of visual processing, is attenuated during the AB. Here we asked whether such changes in V1 activity during the AB arise in the initial feedforward sweep of stimulus input, or instead reflect the influence of feedback signals from higher cortical areas. METHODOLOGY/PRINCIPAL FINDINGS: EEG signals were recorded while participants monitored a sequential stream of distractor letters for two target digits (T1 and T2. Neural responses associated with an irrelevant probe stimulus presented simultaneously with T2 were measured using an ERP marker--the C1 component--that reflects initial perceptual processing of visual information in V1. As expected, T2 accuracy was compromised when the inter-target interval was brief, reflecting an AB deficit. Critically, however, the magnitude of the early C1 component evoked by the probe was not reduced during the AB. CONCLUSIONS/SIGNIFICANCE: Our finding that early sensory processing of irrelevant probe stimuli is not suppressed during the AB is consistent with theoretical models that assume that the bottleneck underlying the AB arises at a post-perceptual stage of processing. This suggests that reduced neural activity in V1 during the AB is driven by re-entrant signals from extrastriate areas that regulate early cortical activity via feedback connections with V1.

  20. Roles and responsibilities in the secondary level eye care model

    Directory of Open Access Journals (Sweden)

    Saibaba Saravanan

    2005-12-01

    Full Text Available In any secondary level eye care clinic, a number of tasks must be completed. In different countries and different settings, different people will carry out these tasks. The manager is responsible for ensuring that all the tasks are covered, that people are carefully selected to perform them, and that staff are supported and managed. The International Centre for Advancement of Rural Eye Care (ICARE, within the L.V. Prasad Eye Institute (LVPEI in India, has evolved an eye care team to provide secondary level eye care services to a population of 0.5 to 1 million. The ICARE model emphasises that all cadres of clinical and non-clinical personnel are equally important. Below is a description of the range of jobs at secondary level centres. The tertiary centre at LVPEI manages leadership and training for this model.

  1. Real Time Eye Template Detection and Tracking

    Directory of Open Access Journals (Sweden)

    Richa Mehta

    2012-06-01

    Full Text Available There has been a growing interest in the field of facial expression recognition especially in the last two decades. An example of such a system is the improvement of driver carefulness and accident reduction. The driver’s face is tracked while he is driving and he is warned if there seems to be an alerting fact that can result in an accident such as sleepy eyes, or looking out of the road. Furthermore, with a facial feature tracker, it becomes possible to play a synthesized avatar so that it imitates the expressions of the performer. Human-Computer Interaction (HCI systems may also be enriched by a facial feature tracker. For a user who is incapable of using her hands, a facial expression controller may be a solution to send limited commands to a computer. Eye blinking is one of the prominent areas to solve many real world problems. The process of blink detection consists of two phases. These are eye tracking followed by detection of blink. The work that has been carried out for eye tracking only is not suitable for eye blink detection. Therefore some approaches had been proposed for eye tracking along with eyes blink detection. In this thesis, real time implementation is done to count number of eye blinks in an image sequence. At last after analyzing all these approaches some of the parameters we obtained on which better performance of eye blink detection algorithm depend. This project focuses on automatic eye blink detection in real time. The aim of this thesis is to count the number of eye blinks in a video. This project will be performed on a video database of the facial expressions.

  2. Startle and blink reflex in high functioning autism.

    Science.gov (United States)

    Erturk, Ozdem; Korkmaz, Baris; Alev, Gulce; Demirbilek, Veysi; Kiziltan, Meral

    2016-06-01

    An important clinical feature of autism is the presence of atypical responses to sensory stimuli. In this study, we investigated if high functioning autistic patients had abnormalities in the blink reflex and the startle reaction to auditory or somatosensory stimuli. Fourteen patients aged between 7 and 16 years were included in the study. We found a longer latency of the blink reflex, an increased duration and amplitude of the auditory startle reaction and a lower presence rate of the somatosensorial startle reaction in autistic patients. To better define the sensorial characteristics of the disease could improve the therapeutic management of children with autism spectrum disorder.

  3. Immune response in the eye following epileptic seizures

    OpenAIRE

    Ahl, Matilda; Avdic, Una; Skoug, Cecilia; Ali, Idrish; Chugh, Deepti; Johansson, Ulrica Englund; Christine T Ekdahl

    2016-01-01

    Background: Epileptic seizures are associated with an immune response in the brain. However, it is not known whether it can extend to remote areas of the brain, such as the eyes. Hence, we investigated whether epileptic seizures induce inflammation in the retina.Methods: Adult rats underwent electrically induced temporal status epilepticus, and the eyes were studied 6 h, 1, and 7 weeks later with biochemical and immunohistochemical analyses. An additional group of animals received CX3CR1 anti...

  4. Correlation between Inter-Blink Interval and Episodic Encoding during Movie Watching.

    Directory of Open Access Journals (Sweden)

    Young Seok Shin

    Full Text Available Human eye blinking is cognitively suppressed to minimize loss of visual information for important real-world events. Despite the relationship between eye blinking and cognitive state, the effect of eye blinks on cognition in real-world environments has received limited research attention. In this study, we focused on the temporal pattern of inter-eye blink interval (IEBI during movie watching and investigated its relationship with episodic memory. As a control condition, 24 healthy subjects watched a nature documentary that lacked a specific story line while electroencephalography was performed. Immediately after viewing the movie, the subjects were asked to report its most memorable scene. Four weeks later, subjects were asked to score 32 randomly selected scenes from the movie, based on how much they were able to remember and describe. The results showed that the average IEBI was significantly longer during the movie than in the control condition. In addition, the significant increase in IEBI when watching a movie coincided with the most memorable scenes of the movie. The results suggested that the interesting episodic narrative of the movie attracted the subjects' visual attention relative to the documentary clip that did not have a story line. In the episodic memory test executed four weeks later, memory performance was significantly positively correlated with IEBI (p<0.001. In summary, IEBI may be a reliable bio-marker of the degree of concentration on naturalistic content that requires visual attention, such as a movie.

  5. The classical pink-eyed dilution mutation affects angiogenic responsiveness.

    Directory of Open Access Journals (Sweden)

    Michael S Rogers

    Full Text Available Angiogenesis is the process by which new blood vessels are formed from existing vessels. Mammalian populations, including humans and mice, harbor genetic variations that alter angiogenesis. Angiogenesis-regulating gene variants can result in increased susceptibility to multiple angiogenesis-dependent diseases in humans. Our efforts to dissect the complexity of the genetic diversity that regulates angiogenesis have used laboratory animals due to the availability of genome sequence for many species and the ability to perform high volume controlled breeding. Using the murine corneal micropocket assay, we have observed more than ten-fold difference in angiogenic responsiveness among various mouse strains. This degree of difference is observed with either bFGF or VEGF induced corneal neovascularization. Ongoing mapping studies have identified multiple loci that affect angiogenic responsiveness in several mouse models. In this study, we used F2 intercrosses between C57BL/6J and the 129 substrains 129P1/ReJ and 129P3/J, as well as the SJL/J strain, where we have identified new QTLs that affect angiogenic responsiveness. In the case of AngFq5, on chromosome 7, congenic animals were used to confirm the existence of this locus and subcongenic animals, combined with a haplotype-based mapping approach that identified the pink-eyed dilution mutation as a candidate polymorphism to explain AngFq5. The ability of mutations in the pink-eyed dilution gene to affect angiogenic response was demonstrated using the p-J allele at the same locus. Using this allele, we demonstrate that pink-eyed dilution mutations in Oca2 can affect both bFGF and VEGF-induced corneal angiogenesis.

  6. The classical pink-eyed dilution mutation affects angiogenic responsiveness.

    Science.gov (United States)

    Rogers, Michael S; Boyartchuk, Victor; Rohan, Richard M; Birsner, Amy E; Dietrich, William F; D'Amato, Robert J

    2012-01-01

    Angiogenesis is the process by which new blood vessels are formed from existing vessels. Mammalian populations, including humans and mice, harbor genetic variations that alter angiogenesis. Angiogenesis-regulating gene variants can result in increased susceptibility to multiple angiogenesis-dependent diseases in humans. Our efforts to dissect the complexity of the genetic diversity that regulates angiogenesis have used laboratory animals due to the availability of genome sequence for many species and the ability to perform high volume controlled breeding. Using the murine corneal micropocket assay, we have observed more than ten-fold difference in angiogenic responsiveness among various mouse strains. This degree of difference is observed with either bFGF or VEGF induced corneal neovascularization. Ongoing mapping studies have identified multiple loci that affect angiogenic responsiveness in several mouse models. In this study, we used F2 intercrosses between C57BL/6J and the 129 substrains 129P1/ReJ and 129P3/J, as well as the SJL/J strain, where we have identified new QTLs that affect angiogenic responsiveness. In the case of AngFq5, on chromosome 7, congenic animals were used to confirm the existence of this locus and subcongenic animals, combined with a haplotype-based mapping approach that identified the pink-eyed dilution mutation as a candidate polymorphism to explain AngFq5. The ability of mutations in the pink-eyed dilution gene to affect angiogenic response was demonstrated using the p-J allele at the same locus. Using this allele, we demonstrate that pink-eyed dilution mutations in Oca2 can affect both bFGF and VEGF-induced corneal angiogenesis.

  7. Resource sharing in the attentional blink

    NARCIS (Netherlands)

    Shapiro, K; Schmitz, F; Martens, S; Hommel, B; Schnitzler, A

    2006-01-01

    Humans have difficulty processing more than one event at a time, as is evidenced by the attentional blink ('blink') phenomenon: the second of two targets in a visual stream of events cannot be reported accurately if it appears between 100 and 500 ms after the first. By using whole-head magnetoenceph

  8. Secondary eyes mediate the response to looming objects in jumping spiders (Phidippus audax, Salticidae).

    Science.gov (United States)

    Spano, Lauren; Long, Skye M; Jakob, Elizabeth M

    2012-12-23

    Some species have sensory systems divided into subsystems with morphologically different sense organs that acquire different types of information within the same modality. Jumping spiders (family Salticidae) have eight eyes. Four eyes are directed anteriorly to view objects in front of the spider: a pair of principal eyes track targets with their movable retinae, while the immobile anterior lateral (AL) eyes have a larger field of view and lower resolution. To test whether the principal eyes, the AL eyes, or both together mediate the response to looming stimuli, we presented spiders with a video of a solid black circle that rapidly expanded (loomed) or contracted (receded). Control spiders and spiders with their principal eyes masked were significantly more likely to back away from the looming stimulus than were spiders with their AL eyes masked. Almost no individuals backed away from the receding stimulus. Our results show that the AL eyes alone mediate the loom response to objects anterior to the spider.

  9. Storage of a naturally acquired conditioned response is impaired in patients with cerebellar degeneration.

    Science.gov (United States)

    Thieme, Andreas; Thürling, Markus; Galuba, Julia; Burciu, Roxana G; Göricke, Sophia; Beck, Andreas; Aurich, Volker; Wondzinski, Elke; Siebler, Mario; Gerwig, Marcus; Bracha, Vlastislav; Timmann, Dagmar

    2013-07-01

    Previous findings suggested that the human cerebellum is involved in the acquisition but not the long-term storage of motor associations. The finding of preserved retention in cerebellar patients was fundamentally different from animal studies which show that both acquisition and retention depends on the integrity of the cerebellum. The present study investigated whether retention had been preserved because critical regions of the cerebellum were spared. Visual threat eye-blink responses, that is, the anticipatory closure of the eyes to visual threats, have previously been found to be naturally acquired conditioned responses. Because acquisition is known to take place in very early childhood, visual threat eye-blink responses can be used to test retention in patients with adult onset cerebellar disease. Visual threat eye-blink responses were tested in 19 adult patients with cerebellar degeneration, 27 adult patients with focal cerebellar lesions due to stroke, 24 age-matched control subjects, and 31 younger control subjects. High-resolution structural magnetic resonance images were acquired in patients to perform lesion-symptom mapping. Voxel-based morphometry was performed in patients with cerebellar degeneration, and voxel-based lesion-symptom mapping in patients with focal disease. Visual threat eye-blink responses were found to be significantly reduced in patients with cerebellar degeneration. Visual threat eye-blink responses were also reduced in patients with focal disease, but to a lesser extent. Visual threat eye-blink responses declined with age. In patients with cerebellar degeneration the degree of cerebellar atrophy was positively correlated with the reduction of conditioned responses. Voxel-based morphometry showed that two main regions within the superior and inferior parts of the posterior cerebellar cortex contributed to expression of visual threat eye-blink responses bilaterally. Involvement of the more inferior parts of the posterior lobe was

  10. Learning not to blink

    Science.gov (United States)

    McKnight, D. M.

    2012-12-01

    In all the fields of earth and environmental science, the pursuit of a research question on a topic that has captured one's interest represents both an exciting challenge and a serious responsibility. There is currently a great need to expand knowledge of many aspects of our changing world. Nonetheless, the scientific community, like other communities, has its own culture and values that can seem to be at odds with one's personal motivation and values. Further, it can seem that scientific institutions are organized in a manner to present a set of hurdles that must be cleared in the pursuit of research questions and dissemination of results. One strategy as a scientist is to deal with this community and its cultural constraints on one's own terms. For example, the scientific community has become necessarily focused on review and assessment in the distribution of limited research resources. Further, rankings to assess impact of journals and tracking of citations are being used commonly in assessing success in research. In mentoring interactions there is an opportunity to share experiences of persistence through the publication process, as new findings cannot make a difference unless they are published. One way to deal with the flaws in these metrics is to remain attuned to one's own sense of the intrinsic value and excitement of the research question being studied, and not lose track of the value of forward progress on tough questions, progress that may not be suitable for the high profile journals with a broad scope. In mentoring, it may be as important to convey that it is possible to have a rewarding scientific career by actively choosing when to compromise, to take risks or to go your own way, as to help students learn research techniques. Possible starting points for such discussions are the old spaghetti westerns starring Clint Eastwood.

  11. Intentional Response Distortion on Personality Tests: Using Eye-Tracking to Understand Response Processes when Faking

    Science.gov (United States)

    van Hooft, Edwin A. J.; Born, Marise Ph.

    2012-01-01

    Intentional response distortion or faking among job applicants completing measures such as personality and integrity tests is a concern in personnel selection. The present study aimed to investigate whether eye-tracking technology can improve our understanding of the response process when faking. In an experimental within-participants design, a…

  12. Pharmacology of reflex blinks in the rat: a novel model for headache research.

    Science.gov (United States)

    Jones, M G; Andreou, A P; McMahon, S B; Spanswick, D

    2016-12-01

    Migraineurs are highly sensitive to the nitric oxide donor glyceryl trinitrate which triggers attacks in many sufferers. In animal studies, glyceryl trinitrate increases neuronal activity in the trigeminovascular pathway and elevates neurotransmitter levels in the brainstem. Many migraineurs also display alterations in blink reflexes, known to involve brainstem circuits. We investigated the effect of GTN on evoked blinks in the anaesthetised rat to determine whether such reflexes may prove useful as the basis for a novel animal model to evaluate potential anti-migraine therapeutic agents. In anaesthetised rats the electromyogram associated with the reflex blink evoked by corneal airpuff was recorded. Rats were infused with glyceryl trinitrate, sumatriptan plus glyceryl trinitrate or vehicle control. Changes in the magnitude of the reflex blink-associated electromyogram following these treatments were measured. Glyceryl trinitrate potentiated the evoked reflex blink-associated EMG response from 2 h after infusion. That effect was abolished by simultaneous infusion of sumatriptan with glyceryl trinitrate. These results show that simple skin surface measurements of evoked electromyographic activity in the rat can reliably detect the evoked blink reflex that can be potentiated by nitric oxide donors. This novel model may be an effective tool for evaluating putative anti-migraine therapeutic agents.

  13. Looking at a predator with the left or right eye: asymmetry of response in lizards.

    Science.gov (United States)

    Bonati, Beatrice; Csermely, Davide; Sovrano, Valeria Anna

    2013-01-01

    Studies carried out with the common wall lizard (Podarcis muralis) revealed preferential use of the left eye during responses to predatory threat in laboratory settings and in the wild. Here we tested lizards under monocular conditions of vision, using temporary eye-patching. Lizards were facing a (simulated) predatory threat laterally, from the side of the non-patched eye. Results showed that lizards with the left eye uncovered during predatory threat used the left eye to monitor the predator, whereas lizards with the right eye uncovered nonetheless tried to use the covered left eye. Moreover, lizards frequently tried to change the eye exposition, making a body C-bend behaviour. Right-eyed lizards showed more frequent and faster C-bending responses than left-eyed lizards, trying to monitor the predator with the left eye even though it was patched. Results fit with asymmetries in spontaneous eye use observed in laboratory conditions and in the wild in this species, confirming that structures located on the right side of the brain (mainly served by the left eye) predominantly attend to predatory threat.

  14. Origin and control of blinking in quantum dots.

    Science.gov (United States)

    Efros, Alexander L; Nesbitt, David J

    2016-08-03

    Semiconductor nanocrystals offer an enormous diversity of potential device applications, based on their size-tunable photoluminescence, high optical stability and 'bottom-up' chemical approaches to self-assembly. However, the promise of such applications can be seriously limited by photoluminescence intermittency in nanocrystal emission, that is, 'blinking', arising from the escape of either one or both of the photoexcited carriers to the nanocrystal surface. In the first scenario, the remaining nanocrystal charge quenches photoluminescence via non-radiative Auger recombination, whereas for the other, the exciton is thought to be intercepted before thermalization and does not contribute to the photoluminescence. This Review summarizes the current understanding of the mechanisms responsible for nanocrystal blinking kinetics as well as core-shell engineering efforts to control such phenomena. In particular, 'softening' of the core-shell confinement potential strongly suppresses non-radiative Auger processes in charged nanocrystals, with successful non-blinking implementations demonstrated in CdSe-CdS core-thick-shell nanocrystals and their modifications.

  15. Relieving the attentional blink in the amblyopic brain with video games.

    Science.gov (United States)

    Li, Roger W; Ngo, Charlie V; Levi, Dennis M

    2015-01-01

    Video game play induces a generalized recovery of a range of spatial visual functions in the amblyopic brain. Here we ask whether video game play also alters temporal processing in the amblyopic brain. When visual targets are presented in rapid succession, correct identification of the first target (T1) can interfere with identification of the second (T2). This is known as the "attentional blink". We measured the attentional blink in each eye of adults with amblyopia before and after 40 hours of active video game play, using a rapid serial visual presentation technique. After videogame play, we observed a ~40% reduction in the attentional blink (identifying T2 200 ms after T1) seen through the amblyopic eye and this improvement in performance transferred substantially to the untrained fellow sound eye. Our experiments show that the enhanced performance cannot be simply explained by eye patching alone, or to improved visual acuity, but is specific to videogame experience. Thus, videogame training might have important therapeutic applications for amblyopia and other visual brain disorders.

  16. Inflammatory responses in the rat superior colliculus after eye enucleation.

    Science.gov (United States)

    Hernandes, Marina S; Britto, Luiz R G

    2014-02-01

    Ocular enucleation induces profound morphological alterations in central visual areas. However, little is known about the response of glial cells and possible inflammatory processes in visual brain areas resulting from eye enucleation. In this study, immunoblotting and immunostaining assays revealed increased expression of astrocyte and microglia markers in the rat superior colliculus (SC) between 1 and 15 days after contralateral enucleation. A transient increase of neuronal COX-2 protein expression was also found in the SC. To evaluate the role of an anti-inflammatory drug in attenuating both COX-2 and glial cell activation, the synthetic glucocorticoid dexamethasone (DEX) was administered (1 mg/kg i.p., for 3 days) to enucleated rats. Immunoblotting data revealed that DEX treatment significantly inhibited COX-2 protein expression. Postlesion immunostaining for astrocyte and microglia markers was also significantly reduced by DEX treatment. These findings suggest that the removal of retinal ganglion cell input generates inflammatory responses in central retinorecipient structures. Copyright © 2013 Elsevier Inc. All rights reserved.

  17. The Effect of Tear Supplementation on Ocular Surface Sensations during the Interblink Interval in Patients with Dry Eye.

    Directory of Open Access Journals (Sweden)

    Lóránt Dienes

    Full Text Available To investigate the characteristics of ocular surface sensations and corneal sensitivity during the interblink interval before and after tear supplementation in dry eye patients.Twenty subjects (41.88±14.37 years with dry eye symptoms were included in the dry eye group. Fourteen subjects (39.13±11.27 years without any clinical signs and/or symptoms of dry eye were included in the control group. Tear film dynamics was assessed by non-invasive tear film breakup time (NI-BUT in parallel with continuous recordings of ocular sensations during forced blinking. Corneal sensitivity to selective stimulation of corneal mechano-, cold and chemical receptors was assessed using a gas esthesiometer. All the measurements were made before and 5 min after saline and hydroxypropyl-guar (HP-guar drops.In dry eye patients the intensity of irritation increased rapidly after the last blink during forced blinking, while in controls there was no alteration in the intensity during the first 10 sec followed by an exponential increase. Irritation scores were significantly higher in dry eye patients throughout the entire interblink interval compared to controls (p0.05.Ocular surface irritation responses due to tear film drying are considerably increased in dry eye patients compared to normal subjects. Although tear supplementation improves the protective tear film layer, and thus reduce unpleasant sensory responses, the rapid rise in discomfort is still maintained and might be responsible for the remaining complaints of dry eye patients despite the treatment.

  18. Shadow response in the blind cavefish Astyanax reveals conservation of a functional pineal eye.

    Science.gov (United States)

    Yoshizawa, Masato; Jeffery, William R

    2008-02-01

    The blind cavefish Astyanax mexicanus undergoes bilateral eye degeneration during embryonic development. Despite the absence of light in the cave environment, cavefish have retained a structurally intact pineal eye. We show here that contrary to visual degeneration in the bilateral eyes, the cavefish pineal eye has conserved the ability to detect light. Larvae of two different Astyanax cavefish populations and the con-specific sighted surface-dwelling form (surface fish) respond similarly to light dimming by shading the pineal eye. As a response to shading, cavefish larvae swim upward vertically. This behavior resembles that of amphibian tadpoles rather than other teleost larvae, which react to shadows by swimming downward. The shadow response is highest at 1.5-days post-fertilization (d.p.f.), gradually diminishes, and is virtually undetectable by 7.5 d.p.f. The shadow response was substantially reduced after surgical removal of the pineal gland from surface fish or cavefish larvae, indicating that it is based on pineal function. In contrast, removal of one or both bilateral eye primordia did not affect the shadow response. Consistent with its light detecting capacity, immunocytochemical studies indicate that surface fish and cavefish pineal eyes express a rhodopsin-like antigen, which is undetectable in the degenerating bilateral eyes of cavefish larvae. We conclude that light detection by the pineal eye has been conserved in cavefish despite a million or more years of evolution in complete darkness.

  19. Eyes Do Not Have it: A Collinear Salient Line Interferes with Visual Search Responses but Not Eye Movements

    Directory of Open Access Journals (Sweden)

    Li Jingling

    2011-05-01

    Full Text Available Our previous study found that a task-irrelevant salient line impaired visual search when the salient line was composite of collinear bars (Jingling, 2010. In this study, we further investigated whether this inhibition can be observed in eye movements. The search display was a lattice of 21 by 27 bars. The task was to discriminate the orientation of a target, which was presented on one of seven bars in the central of search display. One of the columns of the bars was vertical, thus bars on this line were collinear to each other. The other bars were horizontal, making the collinear line salient. The target was on the bars at salient line by chance. Eight participants were recruited, and eye movements were recorded by EyeLink 1,000 with 250 Hz sampling rate. Results of hand response times replicated our previous findings: Responses were slower for targets on the bars at the salient line than that in the background. However, saccadic duration was not statistically different for these two types of targets. Our data showed that a collinear salient line interferes with key press but not eye movements, suggesting that the inhibitory effect emerged later than sensory information process.

  20. A neurodynamic model of the attentional blink.

    Science.gov (United States)

    Fragopanagos, Nickolaos; Kockelkoren, Stephanus; Taylor, John G

    2005-08-01

    A brain-based neural model of attention is used to simulate results for the 'attentional blink', observed when a subject is exposed to a rapid stream of stimuli and required to monitor for two successive targets in the stream. The 'blink' occurs when the time between the first and second targets is 200-500 ms, when there is reduced accuracy for report of the second target. The model gives a qualitative explanation of the phenomenon, especially of how attention is bolstered, during the processing to report of a given stimulus, in order to defend reportable information from attack by distracters.

  1. Detection of Blinking Part from Animated Videos / Pictures

    Directory of Open Access Journals (Sweden)

    Amit Pal

    2014-06-01

    Full Text Available The aim of this thesis is to execute a technique and the region detection of blinking part in gif images, to find out the new method which is capable for it. It is a very difficult task in image mining examines area for extract a blinking part into variations of any size or type of natural blinking image. The intend of this research is to explain this problem by introduce a new technique called Morphology based technique for Extraction and Detection of blinking Region from gif Images which is more capable for area extraction and edge detection of blinking part into any type of gif image edge based and connected component Here we are using the edge based area extraction process which help in detecting and extraction of blinking part and also in fined out the recall rate and precision rate of blinking part of any animated image.

  2. Writing poetry through the eyes of science a teacher's guide to scientific literacy and poetic response

    CERN Document Server

    Gorrell, Nancy

    2012-01-01

    Writing Poetry Through the Eyes of Science: A Teacher's Guide to Scientific Literacy and Poetic Response presents a unique and effective interdisciplinary approach to teaching science poems and science poetry writing in secondary English and science classrooms.

  3. Biology Today: Of Wishbones, Beavers & Blinking.

    Science.gov (United States)

    Flannery, Maura, Ed.

    1989-01-01

    Provided is a discussion of items covering a variety of fascinating biological topics which include: the elasticity of the furcula of starlings in flight, beavers increasing the greenhouse effect, effective invaders, traveling birds, the cuckoo deception, competitive sperm, hearing springs, heat and sight, blinking as punctuation, mutations, and…

  4. Face, eye, and body selective responses in fusiform gyrus and adjacent cortex: an intracranial EEG study.

    Directory of Open Access Journals (Sweden)

    Andrew D Engell

    2014-08-01

    Full Text Available Functional MRI (fMRI studies have investigated the degree to which processing of whole faces, face-parts, and bodies are differentially localized within the fusiform gyrus and adjacent ventral occipitotemporal cortex. While some studies have emphasized the spatial differentiation of processing into discrete areas, others have emphasized the overlap of processing and the importance of distributed patterns of activity. Intracranial EEG (iEEG recorded from subdural electrodes provides excellent temporal and spatial resolution of local neural activity, and thus provides an alternative method to fMRI for studying differences and commonalities in face and body processing. In this study we recorded iEEG from 12 patients while they viewed images of novel faces, isolated eyes, headless bodies, and flowers. ERP analysis identified 69 occipitotemporal sites at which there was a face-, eye-, or body-selective response when contrasted to flowers. However, when comparing faces, eyes, and bodies to each other at these sites, we identified only 3 face-specific, 13 eye-specific, and 1 body-specific electrodes. Thus, at the majority of sites, faces, eyes, and bodies evoked similar responses. However, we identified ten locations at which the amplitude of the responses spatially varied across adjacent electrodes, indicating that the configuration of current sources and sinks were different for faces, eyes, and bodies. Our results also demonstrate that eye-sensitive regions are more abundant and more purely selective than face- or body-sensitive regions, particularly in lateral occipitotemporal cortex.

  5. Face, eye, and body selective responses in fusiform gyrus and adjacent cortex: an intracranial EEG study.

    Science.gov (United States)

    Engell, Andrew D; McCarthy, Gregory

    2014-01-01

    Functional MRI (fMRI) studies have investigated the degree to which processing of whole faces, face-parts, and bodies are differentially localized within the fusiform gyrus and adjacent ventral occipitotemporal cortex. While some studies have emphasized the spatial differentiation of processing into discrete areas, others have emphasized the overlap of processing and the importance of distributed patterns of activity. Intracranial EEG (iEEG) recorded from subdural electrodes provides excellent temporal and spatial resolution of local neural activity, and thus provides an alternative method to fMRI for studying differences and commonalities in face and body processing. In this study we recorded iEEG from 12 patients while they viewed images of novel faces, isolated eyes, headless bodies, and flowers. Event-related potential analysis identified 69 occipitotemporal sites at which there was a face-, eye-, or body-selective response when contrasted to flowers. However, when comparing faces, eyes, and bodies to each other at these sites, we identified only 3 face-specific, 13 eye-specific, and 1 body-specific electrodes. Thus, at the majority of sites, faces, eyes, and bodies evoked similar responses. However, we identified ten locations at which the amplitude of the responses spatially varied across adjacent electrodes, indicating that the configuration of current sources and sinks were different for faces, eyes, and bodies. Our results also demonstrate that eye-sensitive regions are more abundant and more purely selective than face- or body-sensitive regions, particularly in lateral occipitotemporal cortex.

  6. Assessment of Eye Fatigue Caused by 3D Displays Based on Multimodal Measurements

    Directory of Open Access Journals (Sweden)

    Jae Won Bang

    2014-09-01

    Full Text Available With the development of 3D displays, user’s eye fatigue has been an important issue when viewing these displays. There have been previous studies conducted on eye fatigue related to 3D display use, however, most of these have employed a limited number of modalities for measurements, such as electroencephalograms (EEGs, biomedical signals, and eye responses. In this paper, we propose a new assessment of eye fatigue related to 3D display use based on multimodal measurements. compared to previous works Our research is novel in the following four ways: first, to enhance the accuracy of assessment of eye fatigue, we measure EEG signals, eye blinking rate (BR, facial temperature (FT, and a subjective evaluation (SE score before and after a user watches a 3D display; second, in order to accurately measure BR in a manner that is convenient for the user, we implement a remote gaze-tracking system using a high speed (mega-pixel camera that measures eye blinks of both eyes; thirdly, changes in the FT are measured using a remote thermal camera, which can enhance the measurement of eye fatigue, and fourth, we perform various statistical analyses to evaluate the correlation between the EEG signal, eye BR, FT, and the SE score based on the T-test, correlation matrix, and effect size. Results show that the correlation of the SE with other data (FT, BR, and EEG is the highest, while those of the FT, BR, and EEG with other data are second, third, and fourth highest, respectively.

  7. Eye movement responses to health messages on cigarette packages

    Directory of Open Access Journals (Sweden)

    TE Kessels Loes

    2012-07-01

    Full Text Available Abstract Background While the majority of the health messages on cigarette packages contain threatening health information, previous studies indicate that risk information can trigger defensive reactions, especially when the information is self-relevant (i.e., smokers. Providing coping information, information that provides help for quitting smoking, might increase attention to health messages instead of triggering defensive reactions. Methods Eye-movement registration can detect attention preferences for different health education messages over a longer period of time during message exposure. In a randomized, experimental study with 23 smoking and 41 non-smoking student volunteers, eye-movements were recorded for sixteen self-created cigarette packages containing health texts that presented either high risk or coping information combined with a high threat or a low threat smoking-related photo. Results Results of the eye movement data showed that smokers tend to spend more time looking (i.e., more unique fixations and longer dwell time at the coping information than at the high risk information irrespective of the content of the smoking-related photo. Non-smokers tend to spend more time looking at the high risk information than at the coping information when the information was presented in combination with a high threat smoking photo. When a low threat photo was presented, non-smokers paid more attention to the coping information than to the high risk information. Results for the smoking photos showed more attention allocation for low threat photos that were presented in combination with high risk information than for low threat photos in combination with coping information. No attention differences were found for the high threat photos. Conclusions Non-smokers demonstrated an attention preference for high risk information as opposed to coping information, but only when text information was presented in combination with a high threat photo

  8. Light Loop Echoes and Blinking Black Holes

    CERN Document Server

    Boyle, Latham

    2011-01-01

    Radiation emitted near a black hole reaches the observer by multiple paths; and when this radiation varies in time, the time-delays between the various paths generate a "blinking" effect in the observed light curve L(t) or its auto-correlation function xi(T)= . For the particularly important "face-on" configuration (in which the hole is viewed roughly along its spin axis, while the emission comes roughly from its equatorial plane -- e.g. from the inner edge of its accretion disk, or from the violent flash of a nearby/infalling star) we calculate the blinking in detail by computing the time delay Delta t_{j}(r,a) and magnification mu_{j}(r,a) of the jth path (j=1,2,3,...), relative to the primary path (j=0), as a function of the emission radius r and black hole spin 0blinking signal, making it more detectable and more independent of certain astrophysical and observational details. The effect can b...

  9. Rapid response teams seen through the eyes of the nurse.

    Science.gov (United States)

    Shapiro, Susan E; Donaldson, Nancy E; Scott, Mary B

    2010-06-01

    This article reports on the findings of an evaluation project that explored the impact of rapid response teams from the perspective of the nurses who use them-to give voice to the experience of nurses. Interviews with 56 staff nurses were analyzed, using thematic analysis, to describe the impact of rapid response teams on staff nurses' practice; the nurses' perspectives on what constitutes a successful rapid response team; their experiences before, during, and after activating a rapid response team; and the challenges they encountered when rapid response teams were used. Nurses described rapid response teams as quickly bringing needed resources to patients and, when necessary, facilitating patients' transfer to ICUs. They especially appreciated the ability to gather these resources with a single phone call. Nurses also expressed profound relief that rapid response teams were available to expedite patient care; this was so important that some stated they wouldn't work in a facility that didn't have a rapid response team. Successful rapid response systems were described as those in which nurses activated the team without hesitation when they felt it was needed. Challenges to successful use of rapid response teams included mixed messages from leadership about when to activate the team and the need for nurses who were themselves on a rapid response team to leave their patients in order to respond to an activation. Despite some limitations, this evaluation provides much-needed insight into the effects of rapid response teams on nurses' work environment. Further research is needed to explicate how having a successful rapid response team influences nurse recruitment and retention, as well as how such teams affect patient outcomes.

  10. Vestibulo-Cervico-Ocular Responses and Tracking Eye Movements after Prolonged Exposure to Microgravity

    Science.gov (United States)

    Kornilova, L. N.; Naumov, I. A.; Azarov, K. A.; Sagalovitch, S. V.; Reschke, Millard F.; Kozlovskaya, I. B.

    2007-01-01

    The vestibular function and tracking eye movements were investigated in 12 Russian crew members of ISS missions on days 1(2), 4(5-6), and 8(9-10) after prolonged exposure to microgravity (126 to 195 days). The spontaneous oculomotor activity, static torsional otolith-cervico-ocular reflex, dynamic vestibulo-cervico-ocular responses, vestibular reactivity, tracking eye movements, and gaze-holding were studied using videooculography (VOG) and electrooculography (EOG) for parallel eye movement recording. On post-flight days 1-2 (R+1-2) some cosmonauts demonstrated: - an increased spontaneous oculomotor activity (floating eye movements, spontaneous nystagmus of the typical and atypical form, square wave jerks, gaze nystagmus) with the head held in the vertical position; - suppressed otolith function (absent or reduced by one half amplitude of torsional compensatory eye counter-rolling) with the head inclined statically right- or leftward by 300; - increased vestibular reactivity (lowered threshold and increased intensity of the vestibular nystagmus) during head turns around the longitudinal body axis at 0.125 Hz; - a significant change in the accuracy, velocity, and temporal characteristics of the eye tracking. The pattern, depth, dynamics, and velocity of the vestibular function and tracking eye movements recovery varied with individual participants in the investigation. However, there were also regular responses during readaptation to the normal gravity: - suppression of the otolith function was typically accompanied by an exaggerated vestibular reactivity; - the structure of visual tracking (the accuracy of fixational eye rotations, smooth tracking, and gaze-holding) was disturbed (the appearance of correcting saccades, the transition of smooth tracking to saccadic tracking) only in those cosmonauts who, in parallel to an increased reactivity of the vestibular input, also had central changes in the oculomotor system (spontaneous nystagmus, gaze nystagmus).

  11. Capsaicin effects on blinking Efectos de la capsaicina en el parpadeo

    Directory of Open Access Journals (Sweden)

    Fidias E. Leon-Sarmiento

    2005-09-01

    Full Text Available Blinking is a normal human phenomenom involving trigeminal and facial patways. To gain understanding on the neurobiology of blinking, five normal subjects were investigated before and after application of transdermal capsaicin at the forehead for two weeks. No effects of topical capsaicin were detected in eye blink rates. However, when capsaicin was applied to a female subject with blepharospasm, she showed a dramatic restoration of her vision subsequent to blinking modification. Deactivation of abnormal A-to-C fibers cross talks at the trigeminal-facial pathways seems to be the most likely mechanism of such improvement.El parpadeo es un fenómeno normal en los humanos que involucra las vías trigéminas faciales. Con el fin de conocer un poco más la neurobiología de este fenómeno estudiamos cinco individuos normales antes y después de aplicar capsaicina trasdérmica en la frente de cada uno de ellos, por dos semanas. La frecuencia de parpadeo no se alteró con la aplicación de capsaicina tópica. Sin embargo, cuando la misma sustancia se aplicó a una paciente con blefaroespasmo hubo dramática restauración de su visión, la cual fue secundaria a la modificación de la actividad muscular palpebral. La desactivación del cruce patológico de información que pasa de las fibras A a las fibras C, pertenecientes a las vías trigémino-faciales, parece ser el mecanismo de acción relacionado con la aplicación de capsaicina, el que estaría directamente relacionado con la recuperación clínica observada en la paciente con blefaroespasmo.

  12. How the brain blinks : Towards a neurocognitive model of the attentional blink

    NARCIS (Netherlands)

    Hommel, Bernhard; Kessler, Klaus; Schmitz, Frank; Gross, Joachim; Akyürek, Elkan; Shapiro, Kimron; Schnitzler, Alfons

    2006-01-01

    When people monitor a visual stream of rapidly presented stimuli for two targets (T1 and T2), they often miss T2 if it falls into a time window of about half a second after T1 onset-the attentional blink (AB). We provide an overview of recent neuroscientific studies devoted to analyze the neural pro

  13. [Value of blink reflex studies in neurosurgical problems].

    Science.gov (United States)

    Jamjoom, Z; Nahser, H C; Nau, H E

    1983-09-01

    Blinking reflex studies were done in neurosurgical patients with processes in the posterior fossa and idiopathic trigeminal neuralgia. Alterations were found in space occupying, ischemic, and traumatic lesions of the trigemino-facial system. The analysis of the components of the blinking reflex can give hints to the site of the lesion and also to the prognosis of the underlying process.

  14. The Attentional Blink Provides Episodic Distinctiveness : Sparing at a Cost

    NARCIS (Netherlands)

    Wyble, Brad; Bowman, Howard; Nieuwenstein, Mark

    2009-01-01

    The attentional blink (J. E. Raymond. K. L. Shapiro, & K. M. Arnett. 1992) refers to an apparent gap in perception observed when a second target follows a first within several hundred milliseconds. Theoretical and computational work have provided explanations for early sets of blink data, but more r

  15. Two-photon interference from two blinking quantum emitters

    Science.gov (United States)

    Jöns, Klaus D.; Stensson, Katarina; Reindl, Marcus; Swillo, Marcin; Huo, Yongheng; Zwiller, Val; Rastelli, Armando; Trotta, Rinaldo; Björk, Gunnar

    2017-08-01

    We investigate the effect of blinking on the two-photon interference measurement from two independent quantum emitters. We find that blinking significantly alters the statistics in the Hong-Ou-Mandel second-order intensity correlation function g(2 )(τ ) and the outcome of two-photon interference measurements performed with independent quantum emitters. We theoretically demonstrate that the presence of blinking can be experimentally recognized by a deviation from the gD(2 )(0 ) =0.5 value when distinguishable photons from two emitters impinge on a beam splitter. Our findings explain the significant differences between linear losses and blinking for correlation measurements between independent sources and are experimentally verified using a parametric down-conversion photon-pair source. We show that blinking imposes a mandatory cross-check measurement to correctly estimate the degree of indistinguishability of photons emitted by independent quantum emitters.

  16. Eye movement related brain responses to emotional scenes during free viewing

    Science.gov (United States)

    Simola, Jaana; Torniainen, Jari; Moisala, Mona; Kivikangas, Markus; Krause, Christina M.

    2013-01-01

    Emotional stimuli are preferentially processed over neutral stimuli. Previous studies, however, disagree on whether emotional stimuli capture attention preattentively or whether the processing advantage is dependent on allocation of attention. The present study investigated attention and emotion processes by measuring brain responses related to eye movement events while 11 participants viewed images selected from the International Affective Picture System (IAPS). Brain responses to emotional stimuli were compared between serial and parallel presentation. An “emotional” set included one image with high positive or negative valence among neutral images. A “neutral” set comprised four neutral images. The participants were asked to indicate which picture—if any—was emotional and to rate that picture on valence and arousal. In the serial condition, the event-related potentials (ERPs) were time-locked to the stimulus onset. In the parallel condition, the ERPs were time-locked to the first eye entry on an image. The eye movement results showed facilitated processing of emotional, especially unpleasant information. The EEG results in both presentation conditions showed that the LPP (“late positive potential”) amplitudes at 400–500 ms were enlarged for the unpleasant and pleasant pictures as compared to neutral pictures. Moreover, the unpleasant scenes elicited stronger responses than pleasant scenes. The ERP results did not support parafoveal emotional processing, although the eye movement results suggested faster attention capture by emotional stimuli. Our findings, thus, suggested that emotional processing depends on overt attentional resources engaged in the processing of emotional content. The results also indicate that brain responses to emotional images can be analyzed time-locked to eye movement events, although the response amplitudes were larger during serial presentation. PMID:23970856

  17. Eye movement related brain responses to emotional scenes during free viewing

    Directory of Open Access Journals (Sweden)

    Jaana eSimola

    2013-08-01

    Full Text Available Emotional stimuli are preferentially processed over neutral stimuli. Previous studies, however, disagree on whether emotional stimuli capture attention preattentively or whether the processing advantage is dependent on allocation of attention. The present study investigated attention and emotion processes by measuring brain responses related to eye movement events while 11 participants viewed images selected from the International Affective Picture System (IAPS. Brain responses to emotional stimuli were compared between serial and parallel presentation. An ‘emotional’ set included one image with high positive or negative valence among neutral images. A ‘neutral’ set comprised four neutral images. The participants were asked to indicate which picture - if any - was emotional and to rate that picture on valence and arousal. In the serial condition, the event-related potentials (ERPs were time-locked to the stimulus onset. In the parallel condition, the ERPs were time-locked to the first eye entry on an image. The eye movement results showed facilitated processing of emotional, especially unpleasant information. The EEG results in both presentation conditions showed that the LPP (‘late positive potential’ amplitudes at 400–500 ms were enlarged for the unpleasant and pleasant pictures as compared to neutral pictures. Moreover, the unpleasant scenes elicited stronger responses than pleasant scenes. The ERP results, however, did not support parafoveal emotional processing, although the eye movement results suggested faster attention capture by emotional stimuli. Our findings, thus, suggested that emotional processing depends on overt attentional resources engaged in the processing of emotional content. The results also indicate that brain responses to emotional images can be analyzed time-locked to eye movement events, although the response amplitudes were larger during serial presentation.

  18. Eye movement related brain responses to emotional scenes during free viewing.

    Science.gov (United States)

    Simola, Jaana; Torniainen, Jari; Moisala, Mona; Kivikangas, Markus; Krause, Christina M

    2013-01-01

    Emotional stimuli are preferentially processed over neutral stimuli. Previous studies, however, disagree on whether emotional stimuli capture attention preattentively or whether the processing advantage is dependent on allocation of attention. The present study investigated attention and emotion processes by measuring brain responses related to eye movement events while 11 participants viewed images selected from the International Affective Picture System (IAPS). Brain responses to emotional stimuli were compared between serial and parallel presentation. An "emotional" set included one image with high positive or negative valence among neutral images. A "neutral" set comprised four neutral images. The participants were asked to indicate which picture-if any-was emotional and to rate that picture on valence and arousal. In the serial condition, the event-related potentials (ERPs) were time-locked to the stimulus onset. In the parallel condition, the ERPs were time-locked to the first eye entry on an image. The eye movement results showed facilitated processing of emotional, especially unpleasant information. The EEG results in both presentation conditions showed that the LPP ("late positive potential") amplitudes at 400-500 ms were enlarged for the unpleasant and pleasant pictures as compared to neutral pictures. Moreover, the unpleasant scenes elicited stronger responses than pleasant scenes. The ERP results did not support parafoveal emotional processing, although the eye movement results suggested faster attention capture by emotional stimuli. Our findings, thus, suggested that emotional processing depends on overt attentional resources engaged in the processing of emotional content. The results also indicate that brain responses to emotional images can be analyzed time-locked to eye movement events, although the response amplitudes were larger during serial presentation.

  19. Naked eye plasmonic indicator with multi-responsive polymer brush as signal transducer and amplifier.

    Science.gov (United States)

    Wang, Tieqiang; Yu, Ye; Chen, Dan; Wang, Shuli; Zhang, Xuemin; Li, Yunong; Zhang, Junhu; Fu, Yu

    2017-02-02

    For decades, plasmonic nanostructures have been used as important optical sensing platforms, however, the necessity of sensitive optical instruments for detection greatly limits their practical application. Herein, a multi-responsive naked eye plasmonic indicator has been prepared through introduction of a responsive polymer brush (PNIPAm) into the cavity of a Ag nanovolcano array (Ag NVA). According to the phase change of the PNIPAm brush under different external conditions, the as-prepared Ag NVA shows responsive monochromatic colors, which allow the Ag NVA to serve as a plasmonic indicator detected by the naked eye. Importantly, the as-prepared Ag NVA also possesses a rapid response rate as well as excellent repeatability, and is compatible with conventional micro-fabrication methods. All of these excellent features make the as-prepared Ag NVA an attractive candidate for future optical indicating and intelligent color display applications.

  20. Development of criteria for evaluating clinical response in thyroid eye disease using a modified Delphi technique

    DEFF Research Database (Denmark)

    Douglas, Raymond S; Tsirbas, Angelo; Gordon, Mark;

    2009-01-01

    OBJECTIVE: To identify components of a provisional clinical response index for thyroid eye disease using a modified Delphi technique. METHODS: The International Thyroid Eye Disease Society conducted a structured, 3-round Delphi exercise establishing consensus for a core set of measures for clinical...... exercise, we developed provisional core measures for assessing disease activity and severity in clinical trials of therapies for thyroid eye disease. These measures will be iteratively refined for use in multicenter clinical trials.......% of participants) rated 153 criteria in Delphi 3 (67 criteria were excluded because of redundancy). Criteria with a mean greater than 6 (1 = least appropriate to 9 = most appropriate) were further evaluated by the nominal group technique and provisional core measures were chosen. CONCLUSIONS: Using a Delphi...

  1. The psychometric properties of the "Reading the Mind in the Eyes" Test: an item response theory (IRT) analysis.

    Science.gov (United States)

    Preti, Antonio; Vellante, Marcello; Petretto, Donatella R

    2017-05-01

    The "Reading the Mind in the Eyes" Test (hereafter: Eyes Test) is considered an advanced task of the Theory of Mind aimed at assessing the performance of the participant in perspective-takingthat is, the ability to sense or understand other people's cognitive and emotional states. In this study, the item response theory analysis was applied to the adult version of the Eyes Test. The Italian version of the Eyes Test was administered to 200 undergraduate students of both genders (males = 46%). Modified parallel analysis (MPA) was used to test unidimensionality. Marginal maximum likelihood estimation was used to fit the 1-, 2-, and 3-parameter logistic (PL) model to the data. Differential Item Functioning (DIF) due to gender was explored with five independent methods. MPA provided evidence in favour of unidimensionality. The Rasch model (1-PL) was superior to the other two models in explaining participants' responses to the Eyes Test. There was no robust evidence of gender-related DIF in the Eyes Test, although some differences may exist for some items as a reflection of real differences by group. The study results support a one-factor model of the Eyes Test. Performance on the Eyes Test is defined by the participant's ability in perspective-taking. Researchers should cease using arbitrarily selected subscores in assessing the performance of participants to the Eyes Test. Lack of gender-related DIF favours the use of the Eyes Test in the investigation of gender differences concerning empathy and social cognition.

  2. Looking at vision : Eye/face/head tracking of consumers for improved marketing decisions

    NARCIS (Netherlands)

    Wedel, M.; Pieters, R.; Moutinho, L.; Bigné, E.; Manrai (eds.), A.K.

    Against the backdrop of the rapid growth of the use eye tracking and facial recognition methodology, this chapter discusses the measurement of eye movements, facial expression of emotions, pupil dilation, eye blinks and head movements. After discussing some of the main research findings in the

  3. 瞬目后不同注视时间的角膜地形图变化%Corneal topography changes at different time of fixation after blinking

    Institute of Scientific and Technical Information of China (English)

    王若洁; 郑穗联; 苏小夏; 邱梭; 施明光

    2010-01-01

    目的 分析比较非干眼与干眼瞬目后不同注视时间的角膜地形图变化,以探讨最后一次瞬目后进行角膜地形图摄影的最佳时间.方法 应用角膜地形图仪检测非于眼(30只眼)和干眼(30只眼),其中非干眼在最后一次完整瞬目后的5s、15s、30s时进行摄影,干眼在正常瞬目情况下,其中一次完整瞬目后的5s进行摄影,分别记录角膜不规则指数(CIM)、形态系数(SF).结果 非干眼瞬目后5s、15s、30s的CIM值明显增大(P<O.05),而SF差异无统计学意义.干眼患者瞬目后5s的CIM、SF值分别1.15±0.55、0.28±0.14.与非干眼相比,平均CIM值明显大于非干眼瞬目后5s的CIM值(P<0.01),且大于非干眼瞬目后15s的平均CIM值,小于瞬目后30s的平均CIM值.SF平均值两者无统计学意义(P>0.05).结论 (1)角膜地形图测量准确性与测量时注视时间密切相关,建议在最后一次瞬目后5s内进行摄影.(2)角膜表面规则性与泪膜的均匀涂布有关.%Objective To analyze and compare the changes of corneal topographic parameters at different time of fixation after blinking between non-dry eyes and dry eyes and to investigate the optimal time between the last blink and the acquisition of topographic image. Methods Thirty non-dry eyes and 30 dry eyes were examined using corneal topography system. Photographs were taken at 5, 15 and 30 seconds after a complete blinking in non-dry eyes and were taken at 5 seconds after the last blinking in dry eyes. The main outcome measures were corneal irregularity measure (CIM) and shape factor (SF). Results The mean values of CIM increased significantly during the 30 seconds pause in blinking in non-dry eyes (P <0.05). The mean of CIM and SF values were 1.15± 0.55, 0.28± 0.14 at 5 seconds after the last blink in dry eyes, respectively. The mean values of CIM was significantly greater than that at 5S after a complete blinking in non-eyes (P<0.01). Conclusions The accuracy of the

  4. Camera Mouse Including “Ctrl-Alt-Del” Key Operation Using Gaze, Blink, and Mouth Shape

    Directory of Open Access Journals (Sweden)

    Kohei Arai

    2013-04-01

    Full Text Available This paper presents camera mouse system with additional feature: "CTRL - ALT - DEL" key. The previous gaze-based camera mouse systems are only considering how to obtain gaze and making selection. We proposed gaze-based camera mouse with "CTRL - ALT - DEL" key. Infrared camera is put on top of display while user looking ahead. User gaze is estimated based on eye gaze and head pose. Blinking and mouth detections are used to create "CTR - ALT - DEL" key. Pupil knowledge is used to improve robustness of eye gaze estimation against different users. Also, Gabor filter is used to extract face features. Skin color information and face features are used to estimate head pose. The experiments of each method have done and the results show that all methods work perfectly. By implemented this system, troubleshooting of camera mouse can be done by user itself and makes camera mouse be more sophisticated.

  5. Resolvin D1 Reduces the Immunoinflammatory Response of the Rat Eye following Uveitis

    Directory of Open Access Journals (Sweden)

    Rossi Settimio

    2012-01-01

    Full Text Available This study investigated whether the administration of resolvin D1 to rats with endotoxininduced uveitis (EIU ameliorates the immuno-inflammatory profile of the eye. 24 h after the administration of 200 μg LPS into the footpad of Sprague-Dawley rats, severe changes of the structure of the eye occurred concomitantly with a severe inflammatory and immune response. These latter included strong infiltration of PMN leukocytes CD11b+ T-lymphocytes CD4+ and CD8+ within the eye and a significant release of the cytokines/chemokines TNF-alpha, CXCL8, and RANTES too. Bolus of resolvin D1 (RvD1; 10–100–1000 ng/kg in 200 μL of sterile saline via the tail vein significantly and dose-dependently (i reduced the development of the ocular derangement caused by LPS; (ii reduced the clinical score attributed to EIU; (iii reduced the protein concentration and myeloperoxidase activity (MPO in aqueous humor (AqH; and (iv reduced neutrophils, T-lymphocytes, and cytokines within the eye.

  6. Eye-Tracking as a Measure of Responsiveness to Joint Attention in Infants at Risk for Autism

    Science.gov (United States)

    Navab, Anahita; Gillespie-Lynch, Kristen; Johnson, Scott P.; Sigman, Marian; Hutman, Ted

    2012-01-01

    Reduced responsiveness to joint attention (RJA), as assessed by the Early Social Communication Scales (ESCS), is predictive of both subsequent language difficulties and autism diagnosis. Eye-tracking measurement of RJA is a promising prognostic tool because it is highly precise and standardized. However, the construct validity of eye-tracking…

  7. How do neural responses to eyes contribute to face-sensitive ERP components in young infants? A rapid repetition study.

    Science.gov (United States)

    Hoehl, Stefanie

    2015-04-01

    Several face-sensitive components of the event-related potential (ERP) have been identified in infants, such as the posterior N290 and P400 components. The contribution of eye-sensitive neurons to these components is still unclear, however. A rapid repetition ERP paradigm was used to test 4-month-olds' responses to faces with and without eyes (preceded by houses, i.e., unprimed) and faces with eyes that were preceded by faces with or without eyes (i.e., primed). N290 latency was reduced and P400 amplitude was increased for unprimed faces without eyes compared to intact faces. In addition, N290 latency was reduced for faces preceded by intact faces compared to faces preceded by faces without eyes. Thus, processing speed at the level of the N290 and amplitude of the P400 are affected by the absence of eyes in a face supporting the notion that eye-sensitive neurons contribute to these components in infancy. Findings are discussed in relation to the early development of face processing and infant and adult ERP responses to faces and eyes.

  8. Etiology of frequent-blinking in children%儿童瞬目增多现象的背后涵义

    Institute of Scientific and Technical Information of China (English)

    邹留河; 赵萌

    2012-01-01

    儿童瞬目增多是眼科门诊常见的一种家长主诉,很多患儿被诊断为结膜炎或角膜炎.引起儿童瞬目增多的常见病因包括儿童干眼症、屈光不正、儿童抽动症、过敏性结膜炎等.儿童瞬目增多的误诊不仅会耽误儿童潜在疾病的治疗,还会让患儿承受长期使用眼药水引起的药物性眼表损伤的可能,故应深刻认识引起儿童瞬目增多的病因并有针对性地治疗.%The frequent blinking has became more and more common complaint of children's parents in ophthalmic clinics. It was always dignosed as conjunctivitis or keratitis. In fact, the common causes of pediatric frequent blinking were pediatric dry eye syndrome, refractive error, child Tic disorder, allergic conjunctivitis, and so on. The misdiagnosis of frequent blinking in children not only could delay the proper treatment, but also could make the children suffer from the ocular surface damages related to the eye drops. Therefore, we should thoroughly learn the underlying causes of frequent blinking in children in order to give the proper treatment in time.

  9. Strain-induced effects in colloidal quantum dots: lifetime measurements and blinking statistics

    Energy Technology Data Exchange (ETDEWEB)

    Veilleux, V; Lachance-Quirion, D; Landry, D B; Allen, C Ni [Centre d' optique, photonique et laser (COPL), 2375 rue de la Terrasse, Universite Laval, QC, G1V 0A6 (Canada); Dore, K [Centre de Recherche Universite Laval Robert-Giffard (CRULRG), 2601, de la Canardiere, QC, G1J 2G3 (Canada); Charette, P G, E-mail: claudine.allen@phy.ulaval.ca [Centre d' optique, photonique et laser (COPL), Universite de Sherbrooke, Sherbrooke, J1K 2R1 (Canada)

    2010-04-02

    A series of samples of CdSe/ Cd{sub x}Zn{sub 1-x}S core/shell quantum dots have been synthesized in order to measure the influence of lattice-mismatch-induced strain on the photoluminescence (PL) and blinking behaviour. The PL spectra show a significant variation of the fluorescence wavelength even though the colloidal quantum dots (cQDs) are similar in size. The PL excitation spectra show a gradual splitting of the first exciton level as the proportion of Zn is increased in the shell and as the shell grows. On the other hand, blinking studies clearly demonstrate a significant dependence on the amount of Zn present in the shell. Distributions of on and off times go from the usual power-law distributions to power-law distributions with exponential cut-offs. These cut-offs become increasingly pronounced as the proportion of Zn increases. We interpret these results in the framework of diffusion-controlled electron transfer. Exciton relaxation lifetime measurements strongly suggest that lattice mismatch is responsible for a greater number of defects in core/shell cQDs. Therefore, strain and lattice mismatch are shown to be parameters of significant importance for the electronic structure of nanocrystals, influencing the photoluminescence, exciton relaxation lifetime and blinking behaviour.

  10. Emotional modulation of the attentional blink and the relation to interpersonal reactivity

    Directory of Open Access Journals (Sweden)

    Philipp eKanske

    2013-10-01

    Full Text Available The extent of the attentional blink effect on detection rates in rapid serial visual presentations is modulated by the emotionality of the stimuli. Emotionally salient stimuli are detected more often, even if presented in the attentional blink period, and elicit an enlarged P3 response, which has been interpreted as enhanced consolidation. This effect correlates with individual differences in trait affectivity such as anxiety or dysphoria. Here, we ask if it is also related to the capacity to detect emotions in others, i.e. to interpersonal social traits. We therefore presented emotional and neutral images depicting social scenes as targets in an attentional blink design and measured detection rates and event-related potentials. In addition, we recorded self-reports of empathy as measured by the Interpersonal Reactivity Index. The results show enhanced performance for emotional stimuli and increased P3 amplitudes, which correlated with individual differences in empathy. The data suggest that self-reported empathy goes along with enhanced processing of emotion in social stimuli, even under stimulus conditions that are suboptimal for conscious target detection.

  11. Fighting Accident Using Eye Detection forSmartphones

    Directory of Open Access Journals (Sweden)

    Mohamed A. Mohamed

    2014-08-01

    Full Text Available This paper is an attempt to investigate an important problem and approaches of human eye detection, blinking, and tracking. A new system was proposed and implemented using android technology for smartphones. System creatively reduces accidents due to drivers’ fatigue by focusing on treating the driver after fatigue has been detected to achieve decrease in accident likelihood. Smartphone's have been the important tools in our society for the abundant functions including communication, entertainment and online office etc. as the pivotal devices of mobile computing. Smartphone development has also become more important than before. Android is one of the emerging leading operating systems for smartphones as an open source system platform. Many smartphones have adopted this platform and more smartphones will do so in the future. The proposed system is well-suited for real world driving conditions since it can be non-intrusive by using video cameras to detect changes. Driver operation and vehicle behavior can be implemented by equipping automobiles with the ability to monitoring the response of the driver. This involves periodically requesting the driver to send a response to the system to indicate alertness. The propose system based on eyes closer count & yawning count of the driver. By monitoring the eyes and face, it is believed that the symptoms of driver fatigue can be detected early enough to avoid a car accident and providing the driver with a warning if the driver takes his or her eye off the road.

  12. Children with autism spectrum disorders show abnormal conditioned response timing on delay, but not trace, eyeblink conditioning.

    Science.gov (United States)

    Oristaglio, J; Hyman West, S; Ghaffari, M; Lech, M S; Verma, B R; Harvey, J A; Welsh, J P; Malone, R P

    2013-09-17

    Children with autism spectrum disorder (ASD) and age-matched typically-developing (TD) peers were tested on two forms of eyeblink conditioning (EBC), a Pavlovian associative learning paradigm where subjects learn to execute an appropriately-timed eyeblink in response to a previously neutral conditioning stimulus (CS). One version of the task, trace EBC, interposes a stimulus-free interval between the presentation of the CS and the unconditioned stimulus (US), a puff of air to the eye which causes the subjects to blink. In delay EBC, the CS overlaps in time with the delivery of the US, usually with both stimuli terminating simultaneously. ASD children performed normally during trace EBC, exhibiting no differences from TD subjects with regard to the learning rate or the timing of the conditioned response. However, when subsequently tested on delay EBC, subjects with ASD displayed abnormally-timed conditioned eye blinks that began earlier and peaked sooner than those of TD subjects, consistent with previous findings. The results suggest an impaired ability of children with ASD to properly time conditioned eye blinks which appears to be specific to delay EBC. We suggest that this deficit may reflect a dysfunction of the cerebellar cortex in which increases in the intensity or duration of sensory input can temporarily disrupt the accuracy of motor timing over short temporal intervals.

  13. A moving overlay shrinks the attentional blink.

    Science.gov (United States)

    Chua, Fook K

    2015-01-01

    This report describes a study examining the effects of overlaying a veil of spots on the letters in a central rapid serial visual presentation stream. Observers identified two target letters (T1 and T2, respectively) embedded in a stream of distractor letters printed in a different color. In Experiment 1, the attentional blink (AB) diminished when a different overlay veiled each letter, such that the spots appeared to move as the letters changed. Experiment 2 concerned whether the performance enhancement occurred because the overlay hampered processing of the lag 1 distractor, thus weakening the distractor's interference with T1. Experiment 3 focused on how changing the overlay at or around T1 affected the AB. The attention disengagement hypothesis was proposed to explain the common theme in the results-that performance was only enhanced when different overlays were applied to the T1 and lag 1 frames. The claim is that the AB reflects a failure of prompt attentional disengagement from T1, which, in turn, delays reengagement when T2 appears shortly thereafter. When T1's disappearance is accompanied by an overlay change, the perceptual system gets an additional cue signaling that the visual scene has changed, thereby inducing attentional disengagement. Apart from facilitating prompt reengagement at the next target, earlier disengagement also improves target recovery by excluding features of the trailing item, likely to be a distractor, from working memory.

  14. Eye movements and hazard perception in police pursuit and emergency response driving.

    Science.gov (United States)

    Crundall, David; Chapman, Peter; Phelps, Nicola; Underwood, Geoffrey

    2003-09-01

    How do police cope with the visual demands placed on them during pursuit driving? This study compared the hazard ratings, eye movements, and physiological responses of police drivers with novice and with age-matched control drivers while viewing video clips of driving taken from police vehicles. The clips included pursuits, emergency responses, and control drives. Although police drivers did not report more hazards than the other participants reported, they had an increased frequency of electrodermal responses while viewing dangerous clips and a greater visual sampling rate and spread of search. However, despite an overall police advantage in oculomotor and physiological measures, all drivers had a reduced spread of search in nighttime pursuits because of the focusing of overt attention.

  15. The Effect of Noseband Tightening on Horses' Behavior, Eye Temperature, and Cardiac Responses.

    Directory of Open Access Journals (Sweden)

    Kate Fenner

    Full Text Available Restrictive nosebands are common in equestrian sport. This is concerning, as recent evidence suggests that very tight nosebands can cause a physiological stress response, and may compromise welfare. The objective of the current study was to investigate relationships that noseband tightness has with oral behavior and with physiological changes that indicate a stress response, such as increases in eye temperature (measured with infrared thermography and heart rate and decreases in heart rate variability (HRV. Horses (n = 12 wearing a double bridle and crank noseband, as is common in dressage at elite levels, were randomly assigned to four treatments: unfastened noseband (UN, conventional area under noseband (CAUN with two fingers of space available under the noseband, half conventional area under noseband (HCAUN with one finger of space under the noseband, and no area under the noseband (NAUN. During the tightest treatment (NAUN, horse heart rate increased (P = 0.003, HRV decreased (P < 0.001, and eye temperature increased (P = 0.011 compared with baseline readings, indicating a physiological stress response. The behavioral results suggest some effects from bits alone but the chief findings are the physiological readings that reflect responses to the nosebands at their tightest. Chewing decreased during the HCAUN (P < 0.001 and NAUN (P < 0.001 treatments. Yawning rates were negligible in all treatments. Similarly, licking was eliminated by the NAUN treatment. Following the removal of the noseband and double bridle during the recovery session, yawning (P = 0.015, swallowing (P = 0.003, and licking (P < 0.001 significantly increased compared with baseline, indicating a post-inhibitory rebound response. This suggests a rise in motivation to perform these behaviors and implies that their inhibition may place horses in a state of deprivation. It is evident that a very tight noseband can cause physiological stress responses and inhibit the expression of

  16. Delayed working memory consolidation during the attentional blink.

    Science.gov (United States)

    Vogel, Edward K; Luck, Steven J

    2002-12-01

    After the detection of a target (T1) in a rapid stream of visual stimuli, there is a period of 400-600 msec during which a subsequent target (T2) is missed. This impairment in performance has been labeled the attentional blink. Recent theories propose that the attentional blink reflects a bottleneck in working memory consolidation such that T2 cannot be consolidated until after T1 is consolidated, and T2 is therefore masked by subsequent stimuli if it is presented while T1 is being consolidated. In support of this explanation, Giesbrecht & Di Lollo (1998) found that when T2 is the final item in the stimulus stream, no attentional blink is observed, because there are no subsequent stimuli that might mask T2. To provide a direct test of this explanation of the attentional blink, in the present study we used the P3 component of the event-related potential waveform to track the processing of T2. When T2 was followed by a masking item, we found that the P3 wave was completely suppressed during the attentional blink period, indicating that T2 was not consolidated in working memory. When T2 was the last item in the stimulus stream, however, we found that the P3 wave was delayed but not suppressed, indicating that T2 consolidation was not eliminated but simply delayed. These results are consistent with a fundamental limit on the consolidation of information in working memory.

  17. Probing and controlling fluorescence blinking of single semiconductor nanoparticles

    Directory of Open Access Journals (Sweden)

    Hsien-Chen Ko

    2011-02-01

    Full Text Available In this review we present an overview of the experimental and theoretical development on fluorescence intermittency (blinking and the roles of electron transfer in semiconductor crystalline nanoparticles. Blinking is a very interesting phenomenon commonly observed in single molecule/particle experiments. Under continuous laser illumination, the fluorescence time trace of these single nanoparticles exhibit random light and dark periods. Since its first observation in the mid-1990s, this intriguing phenomenon has attracted wide attention among researchers from many disciplines. We will first present the historical background of the discovery and the observation of unusual inverse power-law dependence for the waiting time distributions of light and dark periods. Then, we will describe our theoretical modeling efforts to elucidate the causes for the power-law behavior, to probe the roles of electron transfer in blinking, and eventually to control blinking and to achieve complete suppression of the blinking, which is an annoying feature in many applications of quantum dots as light sources and fluorescence labels for biomedical imaging.

  18. Surgical Responses of Medial Rectus Muscle Recession in Thyroid Eye Disease-Related Esotropia.

    Directory of Open Access Journals (Sweden)

    In Jeong Lyu

    Full Text Available We evaluate the surgical outcomes and surgical responses of medial rectus muscle (MR recession patients with thyroid eye disease (TED-related esotropia (ET. The surgical dose-response curves 1 week postoperatively and at the final visit were analyzed. Univariable and multivariable linear regression analyses were applied to investigate factors influencing surgical dose-response. A total of 43 patients with TED-related ET that underwent MR recession were included. The final success rate was 86.0% and the rate of undercorrection was 14.0%. The surgical dose-response curves of TED-related ET showed a gentle slope compared with those of standard surgical tables. In the univariable model, simultaneous vertical rectus muscle recession was the only significant factor influencing surgical dose-response of MR recession in TED-related ET (β = -0.397, P = 0.044. In a model adjusted for age, sex, type of surgery, and preoperative horizontal angle of deviation, simultaneous vertical rectus muscle recession showed marginal significance (β = -0.389, P = 0.064. The surgical dose-response curve of TED-related ET was unique. Simultaneous vertical rectus muscle recession was associated with increased surgical dose-response in TED-related ET.

  19. Triple helix conformation-specific blinking of Cy3 in DNA.

    Science.gov (United States)

    Kawai, Kiyohiko; Maruyama, Atsushi

    2015-03-21

    We report that Cy3 undergoes triple helix conformation-specific blinking in DNA. Blinking patterns were affected by the stabilization of the Hoogsteen base-pair, suggesting that not only the presence but also the fluctuating behaviour of the triple helix can be monitored by the changes in the Cy3 blinking patterns.

  20. Cognitive and Ocular Factors Jointly Determine Pupil Responses under Equiluminance.

    Directory of Open Access Journals (Sweden)

    Tomas Knapen

    Full Text Available Changes in pupil diameter can reflect high-level cognitive signals that depend on central neuromodulatory mechanisms. However, brain mechanisms that adjust pupil size are also exquisitely sensitive to changes in luminance and other events that would be considered a nuisance in cognitive experiments recording pupil size. We implemented a simple auditory experiment involving no changes in visual stimulation. Using finite impulse-response fitting we found pupil responses triggered by different types of events. Among these are pupil responses to auditory events and associated surprise: cognitive effects. However, these cognitive responses were overshadowed by pupil responses associated with blinks and eye movements, both inevitable nuisance factors that lead to changes in effective luminance. Of note, these latter pupil responses were not recording artifacts caused by blinks and eye movements, but endogenous pupil responses that occurred in the wake of these events. Furthermore, we identified slow (tonic changes in pupil size that differentially influenced faster (phasic pupil responses. Fitting all pupil responses using gamma functions, we provide accurate characterisations of cognitive and non-cognitive response shapes, and quantify each response's dependence on tonic pupil size. These results allow us to create a set of recommendations for pupil size analysis in cognitive neuroscience, which we have implemented in freely available software.

  1. The attentional blink as an indicator of sexual interest

    Directory of Open Access Journals (Sweden)

    Susan Mac Conaill

    2012-05-01

    Full Text Available Using implicit measures in psychological assessment is new in research. The Attentional Blink is a widely supported phenomenon in the cognitive literature. It has been reported that emotionally salient stimuli, particularly those of a sexual nature, can produce it, leading to lower recall of a neutral target presented after the stimulus item. This study looked at the Attentional Blink as a measure of sexual interest. It also looked at the use of computer-generated (CG images as an alternative to real images. Findings showed that nude images produced the largest Attentional Blink, real images are most effective, and CG images produced some effect. These finding are promising for the development of CG images of children for use in paedophile assessment.

  2. Dry Eye

    Science.gov (United States)

    ... Eye > Facts About Dry Eye Facts About Dry Eye This information was developed by the National Eye ... the best person to answer specific questions. Dry Eye Defined What is dry eye? Dry eye occurs ...

  3. Eye Allergies

    Science.gov (United States)

    ... Español Eye Health / Eye Health A-Z Eye Allergies Sections What Are Eye Allergies? Eye Allergy Symptoms ... allergy diagnosis Eye allergy treatment What Are Eye Allergies? Written by: David Turbert Reviewed by: Brenda Pagan- ...

  4. Familiarity and Recollection Produce Distinct Eye Movement, Pupil and Medial Temporal Lobe Responses when Memory Strength Is Matched

    Science.gov (United States)

    Kafkas, Alexandros; Montaldi, Daniela

    2012-01-01

    Two experiments explored eye measures (fixations and pupil response patterns) and brain responses (BOLD) accompanying the recognition of visual object stimuli based on familiarity and recollection. In both experiments, the use of a modified remember/know procedure led to high confidence and matched accuracy levels characterising strong familiarity…

  5. Utilizing an eye tracker device for operator support

    NARCIS (Netherlands)

    Greef, T.E. de; Lafeber, H.

    2007-01-01

    At present a number of studies have attempted to embed eye-tracking devices into closed-loop systems to augment the cognitive state of the human operator. It has been demonstrated that the pupil diameter and blinking frequency serve as such indicators. Although these two factors serve cognitive

  6. The Role of the Immune Response in the Pathogenesis of Thyroid Eye Disease: A Reassessment.

    Directory of Open Access Journals (Sweden)

    James T Rosenbaum

    Full Text Available Although thyroid eye disease is a common complication of Graves' disease, the pathogenesis of the orbital disease is poorly understood. Most authorities implicate the immune response as an important causal factor. We sought to clarify pathogenesis by using gene expression microarray.An international consortium of ocular pathologists and orbital surgeons contributed formalin fixed orbital biopsies. RNA was extracted from orbital tissue from 20 healthy controls, 25 patients with thyroid eye disease (TED, 25 patients with nonspecific orbital inflammation (NSOI, 7 patients with sarcoidosis and 6 patients with granulomatosis with polyangiitis (GPA. Tissue was divided into a discovery set and a validation set. Gene expression was quantified using Affymetrix U133 Plus 2.0 microarrays which include 54,000 probe sets.Principal component analysis showed that gene expression from tissue from patients with TED more closely resembled gene expression from healthy control tissue in comparison to gene expression characteristic of sarcoidosis, NSOI, or granulomatosis with polyangiitis. Unsupervised cluster dendrograms further indicated the similarity between TED and healthy controls. Heat maps based on gene expression for cytokines, chemokines, or their receptors showed that these inflammatory markers were associated with NSOI, sarcoidosis, or GPA much more frequently than with TED.This is the first study to compare gene expression in TED to gene expression associated with other causes of exophthalmos. The juxtaposition shows that inflammatory markers are far less characteristic of TED relative to other orbital inflammatory diseases.

  7. Comparison of Photopic Negative Response of Full-Field and Focal Electroretinograms in Detecting Glaucomatous Eyes

    Directory of Open Access Journals (Sweden)

    Shigeki Machida

    2011-01-01

    Full Text Available Purpose. To compare the photopic negative response (PhNR of the full-field electroretinogram (ERG to the PhNR of the focal ERGs in detecting glaucoma. Methods. One hundred and three eyes with glaucoma and 42 normal eyes were studied. Full-field ERGs were elicited by red stimuli on a blue background. The focal ERGs were elicited by a 15∘ white stimulus spot centered on the macula, the superotemporal or the inferotemporal areas of the macula. Results. In early glaucoma, the areas under the receiver operating characteristic curves (AUCs were significantly larger for the focal PhNR (0.863–0.924 than those for the full-field PhNR (0.666–0.748 (P<.05. The sensitivity was significantly higher for the focal PhNR than for the full-field PhNR in early (P<.01 and intermediate glaucoma (P<.05. In advanced glaucoma, there was no difference in the AUCs and sensitivities between the focal and full-field PhNRs. Conclusions. The focal ERG has the diagnostic ability with higher sensitivity in detecting early and intermediate glaucoma than the full-field ERG.

  8. Shadow response in the blind cavefish Astyanax reveals conservation of a functional pineal eye

    OpenAIRE

    2008-01-01

    The blind cavefish Astyanax mexicanus undergoes bilateral eye degeneration during embryonic development. Despite the absence of light in the cave environment, cavefish have retained a structurally intact pineal eye. We show here that contrary to visual degeneration in the bilateral eyes, the cavefish pineal eye has conserved the ability to detect light. Larvae of two different Astyanax cavefish populations and the con-specific sighted surface-dwelling form (surface fish) respond similarly to ...

  9. 儿童异常瞬目症的病因及治疗%Etiological factor and treatment of abnormal blinking in children

    Institute of Scientific and Technical Information of China (English)

    杜芬; 陶利娟

    2015-01-01

    儿童频繁眨眼,每分钟达15次以上,不伴有面肌痉挛和其他全身症状,具有相对独立的临床症状,无神经系统疾病,称为儿童多瞬症或儿童异常瞬目症;若合并眼部器质性病变或神经系统疾病者称为儿童瞬目综合征。该病为小儿眼科的常见病和多发病。儿童频繁瞬目的发病原因有眼部屈光不正、眼表及眼附属器疾患、不良生活及用眼习惯、铅污染、抽动障碍等全身疾患及心理因素。我们可认为大多数儿童的频繁瞬目首先由眼部疾患引起,神经、心理因素异常是加重或使其反复发生的重要原因。认识和鉴别儿童异常瞬目的病因,采取针对性治疗,可避免误诊而延误治疗。%Abnormal eye blinking in children is a disease of frequent eye blinking in children, more than 15 times per minute, without facial spasms and neurological diseases, with relatively independent clinical symptoms. If combining with organic or neurological disease, we consider it as children eye blinking syndrome. It's a common and frequently encountered disease in pediatric ophthalmology. The etiologies include body and psychological disorders, such as refractive errors, ocular surface and ocular adnexal disease, bad habits, lead pollution, tic disorders and so on. We think that most of abnormal eye blinking in children firstly caused by oculopathy, neurological disorders and psychological illness are the important factors for increasing or making it repeatedly happen. Recognizing and identifying the etiologies of abnormal eye blinking in children, so as to take a targeted theray and avoid misdiagnosis and delayed treatment.

  10. Content-specific working memory modulation of the attentional blink

    NARCIS (Netherlands)

    Akyürek, Elkan G.; Abedian-Amiri, Ali; Ostermeier, Sonja M.

    2011-01-01

    Three experiments were conducted to investigate the effects of working memory content on temporal attention in a rapid serial visual presentation attentional blink paradigm. It was shown that categorical similarity between working memory content and the target stimuli pertaining to the attentional t

  11. Timing attention : Cuing target onset interval attenuates the attentional blink

    NARCIS (Netherlands)

    Martens, S; Johnson, A

    2005-01-01

    Three experiments tested whether the attentional blink (AB; a deficit in reporting the second of two targets when it occurs 200-500 msec after the first) can be attenuated by providing information about the target onset asynchrony (TOA) of the second target relative to the first. Blocking the TOA di

  12. Neural responses to fearful eyes in children with conduct problems and varying levels of callous-unemotional traits.

    Science.gov (United States)

    Sebastian, C L; McCrory, E J; Dadds, M R; Cecil, C A M; Lockwood, P L; Hyde, Z H; De Brito, S A; Viding, E

    2014-01-01

    Children with conduct problems (CP) are a heterogeneous group. Those with high levels of callous-unemotional traits (CP/HCU) appear emotionally under-reactive at behavioural and neural levels whereas those with low levels of CU traits (CP/LCU) appear emotionally over-reactive, compared with typically developing (TD) controls. Investigating the degree to which these patterns of emotional reactivity are malleable may have important translational implications. Instructing participants with CP/HCU to focus on the eyes of fearful faces (i.e. the most salient feature) can ameliorate their fear-recognition deficits, but it is unknown whether this is mediated by amygdala response. It is also unknown whether focusing on fearful eyes is associated with increased amygdala reactivity in CP/LCU. Functional magnetic resonance imaging (fMRI) was used to measure neural responses to fearful and calm faces in children with CP/HCU, CP/LCU and TD controls (n = 17 per group). On half of trials participants looked for a blue dot anywhere within target faces; on the other half, participants were directed to focus on the eye region. Reaction time (RT) data showed that CP/LCU were selectively slowed in the fear/eyes condition. For the same condition, CP/LCU also showed increased amygdala and subgenual anterior cingulate cortex (sgACC)/orbitofrontal cortex (OFC) responses compared with TD controls. RT and amygdala response to fear/eyes were correlated in CP/LCU only. No effects of focusing on the eye region were observed in CP/HCU. These data extend the evidence base suggesting that CU traits index meaningful heterogeneity in conduct problems. Focusing on regulating reactive emotional responses may be a fruitful strategy for children with CP/LCU.

  13. Dissociation predicts treatment response in eye-movement desensitization and reprocessing for posttraumatic stress disorder.

    Science.gov (United States)

    Bae, Hwallip; Kim, Daeho; Park, Yong Chon

    2016-01-01

    Using clinical data from a specialized trauma clinic, this study investigated pretreatment clinical factors predicting response to eye-movement desensitization and reprocessing (EMDR) among adult patients diagnosed with posttraumatic stress disorder (PTSD). Participants were evaluated using the Clinician-Administered PTSD Scale (CAPS), the Symptom Checklist-90-Revised, the Beck Depression Inventory, and the Dissociative Experiences Scale before treatment and were reassessed using the CAPS after treatment and at 6-month follow-up. A total of 69 patients underwent an average of 4 sessions of EMDR, and 60 (87%) completed the posttreatment evaluation, including 8 participants who terminated treatment prematurely. Intent-to-treat analysis revealed that 39 (65%) of the 60 patients were classified as responders and 21 (35%) as nonresponders when response was defined as more than a 30% decrease in total CAPS score. The nonresponders had higher levels of dissociation (depersonalization and derealization) and numbing symptoms, but other PTSD symptoms, such as avoidance, hyperarousal, and intrusion, were not significantly different. The number of psychiatric comorbidities was also associated with treatment nonresponse. The final logistic regression model yielded 2 significant variables: dissociation (p < .001) and more than 2 comorbidities compared to none (p < .05). These results indicate that complex symptom patterns in PTSD may predict treatment response and support the inclusion of the dissociative subtype of PTSD in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition.

  14. Analysis of posture and eye movement responses to Coriolis stimulation under 1 G and microgravity conditions.

    Science.gov (United States)

    Sekine, Motoki; Takahashi, Masahiro; Iida, Masahiro

    2009-12-20

    To detect the effect of microgravity on vestibular responses, we conducted Coriolis stimulation experiments at 1 G and μ G. Five men with vision occluded were asked to tilt their head forward while rotating at 100 degrees/sec. Postural changes were recorded by a 3D linear accelerometer, and the distance of upper body movement was derived from recordings of linear acceleration. Eye movements were recorded by a CCD camera. For a second period after commencing head tilt, the upper body moved 10 cm in the direction of inertia input at 1 G, but it moved to the opposite direction at μ G, i.e., 4 cm in the direction of inertia force. Nystagmus peak slow-phase velocity immediately after head tilt and its attenuation process did not differ between 1 G and μ G. The strength of movement sensation and the severity of motion sickness were far weaker at μ G than at 1 G. It was concluded that inertia input is valid to induce postural and sensation responses only when the external reference is given Z axis by gravity. Vestibular ocular response may be maintained at μ G because the head reference is valid even after the external reference becomes arbitrary.

  15. CRITICAL ILLUMINATION FOR RESPONSE TO FLICKERED LIGHT, WITH DRAGONFLY LARVAE (ANAX), IN RELATION TO AREA OF EYE

    Science.gov (United States)

    Crozier, W. J.; Wolf, E.; Zerrahn-Wolf, G.

    1937-01-01

    Arthropods with large convex eyes provide curves of critical illumination for response as a function of flicker frequency (or of visual acuity) which depart from the probability integral type characteristically found for F – log I with vertebrates. By means of experiments with Anax nymphs in which various parts of the eye have been opaqued it is shown that the special shape of the flicker curve is due to the mechanical disadvantage of the periphery of the eye in the reception of light, which is overcome by higher intensities. It is not due to a fixed spatial pattern of intrinsic individual excitabilities of the ommatidia. Reduction of retinal area decreases Fmax., and increases log I for F/Fmax. = 50 per cent. The direct proportionality of Im to P.E.1I is independent of area. Certain relations of these facts to the theory of response to flicker have been discussed. PMID:19873048

  16. Is attentional blink a byproduct of neocortical attractors?

    Directory of Open Access Journals (Sweden)

    David N Silverstein

    2011-05-01

    Full Text Available This study proposes a computational model for attentional blink or blink of the mind, a phenomenon where a human subject misses perception of a later expected visual pattern as two expected visual patterns are presented less than 500 ms apart. A neocortical patch modeled as an attractor network is stimulated with a sequence of 14 patterns 100 ms apart, two of which are expected targets. Patterns that become active attractors are considered recognized. A neocortical patch is represented as a square matrix of hypercolumns, each containing a set of minicolumns with synaptic connections within and across both minicolumns and hypercolumns. Each minicolumn consists of locally connected layer 2/3 pyramidal cells with interacting basket cells and layer 4 pyramidal cells for input stimulation. All neurons are implemented using the Hodgkin-Huxley multi-compartmental cell formalism and include calcium dynamics, and they interact via saturating and depressing AMPA / NMDA and GABAA synapses. Stored patterns are encoded with global connectivity of minicolumns across hypercolumns and active patterns compete as the result of lateral inhibition in the network. Stored patterns were stimulated over time intervals to create attractor interference measurable with synthetic spike traces. This setup corresponds with item presentations in human visual attentional blink studies. Stored target patterns were depolarized while distractor patterns where hyperpolarized to represent expectation of items in working memory. Additionally, studies on the inhibitory effect of benzodiazopines on attentional blink in human subjects were compared with neocortical simulations where the GABAA receptor conductance and decay time were increased. Simulations showed increases in the attentional blink duration, agreeing with observations in human studies.

  17. A mass and solute balance model for tear volume and osmolarity in the normal and the dry eye

    KAUST Repository

    Gaffney, E.A.

    2010-01-01

    Tear hyperosmolarity is thought to play a key role in the mechanism of dry eye, a common symptomatic condition accompanied by visual disturbance, tear film instability, inflammation and damage to the ocular surface. We have constructed a model for the mass and solute balance of the tears, with parameter estimation based on extensive data from the literature which permits the influence of tear evaporation, lacrimal flux and blink rate on tear osmolarity to be explored. In particular the nature of compensatory events has been estimated in aqueous-deficient (ADDE) and evaporative (EDE) dry eye. The model reproduces observed osmolarities of the tear meniscus for the healthy eye and predicts a higher concentration in the tear film than meniscus in normal and dry eye states. The differential is small in the normal eye, but is significantly increased in dry eye, especially for the simultaneous presence of high meniscus concentration and low meniscus radius. This may influence the interpretation of osmolarity values obtained from meniscus samples since they need not fully reflect potential damage to the ocular surface caused by tear film hyperosmolarity. Interrogation of the model suggests that increases in blink rate may play a limited role in compensating for a rise in tear osmolarity in ADDE but that an increase in lacrimal flux, together with an increase in blink rate, may delay the development of hyperosmolarity in EDE. Nonetheless, it is predicted that tear osmolarity may rise to much higher levels in EDE than ADDE before the onset of tear film breakup, in the absence of events at the ocular surface which would independently compromise tear film stability. Differences in the predicted responses of the pre-ocular tears in ADDE compared to EDE or hybrid disease to defined conditions suggest that no single, empirically-accessible variable can act as a surrogate for tear film concentration and the potential for ocular surface damage. This emphasises the need to measure

  18. Sensitization of trigeminal brainstem pathways in a model for tear deficient dry eye.

    Science.gov (United States)

    Rahman, Mostafeezur; Okamoto, Keiichiro; Thompson, Randall; Katagiri, Ayano; Bereiter, David A

    2015-05-01

    Chronic dry eye disease (DE) is associated with an unstable tear film and symptoms of ocular discomfort. The characteristics of symptoms suggest a key role for central neural processing; however, little is known about central neuroplasticity and DE. We used a model for tear deficient DE and assessed effects on eye blink behavior, orbicularis oculi muscle activity (OOemg), and trigeminal brainstem neural activity in male rats. Ocular-responsive neurons were recorded at the interpolaris/caudalis transition (Vi/Vc) and Vc/upper cervical cord (Vc/C1) regions under isoflurane, whereas OOemg activity was recorded under urethane. Spontaneous tear volume was reduced by ∼50% at 14 days after exorbital gland removal. Hypertonic saline-evoked eye blink behavior in awake rats was enhanced throughout the 14 days after surgery. Saline-evoked neural activity at the Vi/Vc transition and in superficial and deep laminae at the Vc/C1 region was greatly enhanced in DE rats. Neurons from DE rats classified as wide dynamic range displayed enlarged convergent periorbital receptive fields consistent with central sensitization. Saline-evoked OOemg activity was markedly enhanced in DE rats compared with controls. Synaptic blockade at the Vi/Vc transition or the Vc/C1 region greatly reduced hypertonic saline-evoked OOemg activity in DE and sham rats. These results indicated that persistent tear deficiency caused sensitization of ocular-responsive neurons at multiple regions of the caudal trigeminal brainstem and enhanced OOemg activity. Central sensitization of ocular-related brainstem circuits is a significant factor in DE and likely contributes to the apparent weak correlation between peripheral signs of tear dysfunction and symptoms of irritation.

  19. The effects of gender and birth control pill use on spontaneous blink rates.

    Science.gov (United States)

    Yolton, D P; Yolton, R L; López, R; Bogner, B; Stevens, R; Rao, D

    1994-11-01

    Two major reference works suggest that men and women blink spontaneously at different rates, but they disagree with regard to which gender blinks faster. Spontaneous blink rates of 59 males and 86 females, 44 of whom were taking birth control (BC) pills, were measured for 5 consecutive minutes. Schirmer test results and tear break-up times (TBUTs) were also obtained. Females taking BC pills blinked at a mean rate of 19.6 times per minute, females not taking birth control pills blinked 14.9 times per minute, and males blinked 14.5 times per minute. There were very large differences between blink rates for individuals in each of the groups. No strong associations were found between spontaneous blink rates and a history of contact lens use, tear break-up time, Schirmer test results, temperature or humidity in the examination room, subject age, or menstrual cycle phase. The 32 percent increase in mean blink rate for females taking BC pills suggests that the pills affect at least one of the mechanisms that control spontaneous blinking, but it is unclear how they accomplish this.

  20. Distractor inhibition predicts individual differences in recovery from the attentional blink.

    Directory of Open Access Journals (Sweden)

    Heleen A Slagter

    Full Text Available BACKGROUND: The attentional blink (AB refers to an impairment in detecting the second of two target stimuli presented in close succession in a rapid stream of distractors. Recent studies indicate that the AB results, in part, from distractor suppression mechanisms, that may be mediated by striatal dopamine. Yet, it is currently unclear how distractor suppression ability may contribute to the AB. Here, we examined whether distractor suppression ability is predictive of an individual's AB depth and/or recovery. In addition, we investigated the relationship between individual spontaneous eye blink rate (sEBR, a marker of striatal dopaminergic functioning, and AB performance. METHODOLOGY/PRINCIPAL FINDINGS: Subjects were presented with rapid streams of letters containing white distractors, a red T1 and a green T2. T2 was presented either at Lag2, Lag4 or Lag10, and preceded by a distractor that shared the same identity as T2 (T2 primed or not (T2 not primed. Replicating previous work [1], we found that slow AB recovery (poor T2 performance in Lag4 vs. Lag10 was associated with a failure to inhibit distractors, as indexed by greater positive priming. However, no relationship was observed between a subject's ability to suppress distractors and AB depth (Lag10 vs. Lag2. Moreover, no relationship between sEBR and AB performance was observed. RESULTS/SIGNIFICANCE: These results indicate that a failure to inhibit distracting information impairs AB recovery, possibly by interfering with target encoding in working memory - but does not affect AB magnitude. The absence of a relationship between individual sEBR and AB performance may be explained by task specifics.

  1. Blink reflex in subjects with different hypnotizability: New findings for an old debate.

    Science.gov (United States)

    Santarcangelo, Enrica L; Briscese, Lucia; Capitani, Simone; Orsini, Paolo; Varanini, Maurizio; Rossi, Bruno; Carboncini, Maria C

    2016-09-01

    Hypnotizability is associated with attentional characteristics whose neurophysiological bases are still under debate. Aim of the study was the assessment of possible hypnotizability-related differences in blink reflex (BR) which has a nociceptive component, is sensitive to attentional-emotional traits and states and is modulated by the brain dopamine content. In 10 high (highs) and 10 low hypnotizable participants (lows) BR was induced by electrical nociceptive stimulation of the right supraorbital nerve in the absence (noW) and in the presence of a visual cue preceding the electrical stimulation by 0.1ms (W01) and by 1ms (W1). The studied variables were: the amplitude of BR components (R1, R2, R3), the amplitude of the quick change (TO) of heart rate ("turbulence") induced by stimulation and its recovery slope (TS), the role of the Behavioral Inhibition/Activation System (BIS/BAS) in the variability BR and cardiac turbulence. Repeated measures ANOVA did not show any significant difference between highs and lows in blink reflex. TO indicated stimulation related HR increase in highs and decrease in lows, TS was larger in highs. BIS and BAS accounted for the warning effects on the BR amplitude and modulated the hypnotizability and warning effects on TO and TS. Findings do not support dopamine based hypnotizability-related attentional abilities. In contrast, they indicate that hypnotizability modulates the short-lasting cardiac response to electrical nociceptive stimulation.

  2. A data-driven algorithm for offline pupil signal preprocessing and eyeblink detection in low-speed eye-tracking protocols.

    Science.gov (United States)

    Pedrotti, Marco; Lei, Shengguang; Dzaack, Jeronimo; Rötting, Matthias

    2011-06-01

    Event detection is the conversion of raw eye-tracking data into events--such as fixations, saccades, glissades, blinks, and so forth--that are relevant for researchers. In eye-tracking studies, event detection algorithms can have a serious impact on higher level analyses, although most studies do not accurately report their settings. We developed a data-driven eyeblink detection algorithm (Identification-Artifact Correction [I-AC]) for 50-Hz eye-tracking protocols. I-AC works by first correcting blink-related artifacts within pupil diameter values and then estimating blink onset and offset. Artifact correction is achieved with data-driven thresholds, and more reliable pupil data are output. Blink parameters are defined according to previous studies on blink-related visual suppression. Blink detection performance was tested with experimental data by visually checking the actual correspondence between I-AC output and participants' eye images, recorded by the eyetracker simultaneously with gaze data. Results showed a 97% correct detection percentage.

  3. Broadband frequency and angular response of a sinusoidal bull’s eye antenna

    Science.gov (United States)

    Beaskoetxea, U.; Navarro-Cía, M.; Beruete, M.

    2016-07-01

    A thorough experimental study of the frequency and beaming angle response of a metallic leaky-wave bull’s eye antenna working at 77 GHz with a sinusoidally corrugated profile is presented. The beam scanning property of these antennas as frequency is varied is experimentally demonstrated and corroborated through theoretical and numerical results. From the experimental results the dispersion diagram of the n  =  -1 and n  =  -2 space harmonics is extracted, and the operation at different frequency regimes is identified and discussed. In order to show the contribution of each half of the antenna, numerical examples of the near-field behavior are also displayed. Overall, experimental results are in good qualitative and quantitative agreement with theoretical and numerical calculations. Finally, an analysis of the beamwidth as a function of frequency is performed, showing that it can achieve values below 1.5° in a fractional bandwidth of 4% around the operation frequency, which is an interesting frequency-stable broadside radiation.

  4. Two-laser optical tweezers with a blinking beam

    Science.gov (United States)

    Lamperska, Weronika; Masajada, Jan; Drobczyński, Sławomir; Gusin, Paweł

    2017-07-01

    We report on a two-laser holographic optical tweezers setup and present its two major advantages over single-laser one. First, the trap stiffness of a weak trapping beam can be measured with a considerable accuracy. Second, a novel method of examining local viscosity of fluid is proposed. Both measurements are performed based on forcing the oscillations of a microscopic polystyrene bead placed between two optical traps. The two beams are generated by separate laser sources and therefore their trapping power can vary. Moreover, a stronger trap 'blinks', modulated by an electronic shutter. The blinking frequency can be precisely adjusted to the experimental conditions, which results in high accuracy of the measurements.

  5. Stimulation of the corneal blinking reflex by ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Tobias, C.; Luce, J.; Yanni, N.; Brustad, T.; Lyman, J.; Kimura, S.

    1961-05-04

    Accelerated alpha particles from the Berkeley heavy-ion linear accelerator were used in a series of experiments designed to elucidate the conditions by which radiation can stimulate or modify nerve action in mammals. Single millisecond pulses in excess of 40,000 radsor pulse trains of less than 1 sec duration elicited the corneal blinking reflex when delivered to the cornea of unanesthetized rabbits. The lowest threshold dose was observed when the Bragg ionization peak was placed at 140 {mu} depth.

  6. A blinking periorbital prosthesis using surface electromyographic signals of the orbicularis oculi muscle

    OpenAIRE

    2015-01-01

    Background Recent advances in human–machine interface technology have enabled the development of multifunctional, primarily orthopedic myoelectric prostheses. We developed a noninvasive blinking periorbital prosthesis that can synchronize with blinking of the intact eyelid by using surface electromyographic signals of the orbicularis oculi muscle. Methods Myoelectric potentials of the orbicularis oculi muscle while blinking were measured with surface electrodes on the eyelid in four healthy a...

  7. Eye redness

    Science.gov (United States)

    Bloodshot eyes; Red eyes; Scleral injection; Conjunctival injection ... There are many causes of a red eye or eyes. Some are medical emergencies. Others are a cause for concern, but not an emergency. Many are nothing to worry about. Eye ...

  8. The effective stimulating pulse for restoration of blink function in unilateral facial nerve paralysis rabbits, verified by a simple FES system.

    Science.gov (United States)

    Jie, Tan; Zhiqiang, Gao; Guodong, Feng; Yubin, Xue; Xiuyong, Ding; Tingting, Cui; Yang, Zhao

    2016-10-01

    The trains of 200 ms biphasic square pulses with the width of 9 ms delivered at 50 Hz were found to be the most suitable and effective mean as stimulation in FES system of restoring the blink function in unilateral facial nerve paralysis rabbit model. FES system is a reliable tool for these patients. Facial paralysis affects thousands of people every year. Many will have long term facial difficulties and the loss of the ability to blink the eye, which can lead to potential loss of the eye. Although many treatments exist, no one approach corrects all the deficits associated with the loss of orbicularis oculi function. FES is a means of providing movement in paralysed muscles to assist with practical activities and one possible way of restoring blink and other functions in these patients. Although some previous researches had investigated the effect of simple FES system on restoration of paralyzed facial muscles, there is still controversy about the appropriate details of the most effective stimulating pulses, such as the frequency, wave pattern and pulse width. Our aim is to find out the parameters of the most appropriate and effective stimulatin verify it by a simple FES system. 24 healthy adult male New Zealand white rabbits were accepted the surgery of right side facial nerve main trunk transaction under general anesthesia as the unilateral facial nerve paralysis models. The platinum tungsten alloy electrodes were implanted in orbicularis oculi muscle. The parameters of stimulus pulses were set to a 200 ms biphasic pulse with different waveforms (square, sine and triangle), different frequencies (25, 50, 100 Hz) and different widths from 1 to 9 ms. Next, we set up a simple FES system to verify the previous results as the stimulus signal. We observed the movement of the both sides of eyelid when eye blink induced by different kinds of pulses. In all animals, the three kinds of waveforms pulse with frequency of 25 Hz could not evoke the smooth blink movement

  9. Blink Rate in Boys with Fragile X Syndrome: Preliminary Evidence for Altered Dopamine Function

    Science.gov (United States)

    Roberts, J. E.; Symons, F. J.; Johnson, A.-M.; Hatton, D. D.; Boccia, M. L.

    2005-01-01

    Background: Dopamine, a neurotransmitter involved in motor and cognitive functioning, can be non-invasively measured via observation of spontaneous blink rates. Blink rates have been studied in a number of clinical conditions including schizophrenia, autism, Parkinsons, and attention deficit/hyperactivity disorder with results implicating either…

  10. Linking Single-Molecule Blinking to Chromophore Structure and Redox Potentials

    NARCIS (Netherlands)

    Stein, Ingo H.; Capone, Stella; Smit, Jochem H.; Baumann, Fabian; Cordes, Thorben; Tinnefeld, Philip

    2012-01-01

    Intensity fluctuations between an ON-state and an OFF-state, also called blinking, are common to all luminescent objects when studied at the level of individuals. We studied blinking of three dyes from a homologous series (Cy3, Cy5, Cy7). The underlying radical anion states were induced by removing

  11. Linking Single-Molecule Blinking to Chromophore Structure and Redox Potentials

    NARCIS (Netherlands)

    Stein, Ingo H.; Capone, Stella; Smit, Jochem H.; Baumann, Fabian; Cordes, Thorben; Tinnefeld, Philip

    2012-01-01

    Intensity fluctuations between an ON-state and an OFF-state, also called blinking, are common to all luminescent objects when studied at the level of individuals. We studied blinking of three dyes from a homologous series (Cy3, Cy5, Cy7). The underlying radical anion states were induced by removing

  12. EEG and eye tracking demonstrate vigilance enhancement with challenge integration

    Directory of Open Access Journals (Sweden)

    Indu Prasad Bodala

    2016-06-01

    Full Text Available Maintaining vigilance is possibly the first requirement for surveillance tasks where personnel are faced with monotonous yet intensive monitoring tasks. Decrement in vigilance in such situations could result in dangerous consequences such as accidents, loss of life and system failure. In this paper, we investigate the possibility to enhance vigilance or sustained attention using ‘challenge integration’, a strategy that integrates a primary task with challenging stimuli. A primary surveillance task (identifying an intruder in a simulated factory environment and a challenge stimulus (periods of rain obscuring the surveillance scene were employed to test the changes in vigilance levels. The effect of integrating challenging events (resulting from artificially simulated rain into the task were compared to the initial monotonous phase. EEG and eye tracking data is collected and analyzed for n = 12 subjects. Frontal midline theta power and frontal theta to parietal alpha power ratio which are used as measures of engagement and attention allocation show an increase due to challenge integration (p < 0.05 in each case. Relative delta band power of EEG also shows statistically significant suppression on the frontoparietal and occipital cortices due to challenge integration (p < 0.05. Saccade amplitude, saccade velocity and blink rate obtained from eye tracking data exhibit statistically significant changes during the challenge phase of the experiment (p < 0.05 in each case. From the correlation analysis between the statistically significant measures of eye tracking and EEG, we infer that saccade amplitude and saccade velocity decrease with vigilance decrement along with frontal midline theta and frontal theta to parietal alpha ratio. Conversely, blink rate and relative delta power increase with vigilance decrement. However, these measures exhibit a reverse trend when challenge stimulus appears in the task suggesting vigilance enhancement. Moreover

  13. Using Eye Tracking to Understand the Responses of Learners to Vocabulary Learning Strategy Instruction and Use

    Science.gov (United States)

    Liu, Pei-Lin

    2014-01-01

    This study examined the influence of morphological instruction in an eye-tracking English vocabulary recognition task. Sixty-eight freshmen enrolled in an English course and received either traditional or morphological instruction for learning English vocabulary. The experimental part of the study was conducted over two-hour class periods for…

  14. The pink eye syndrome does not impair tuber fresh cut wound-related responses

    Science.gov (United States)

    The potato tuber pink eye (PE) syndrome is a costly physiological disorder that results in corruption of the native periderm, susceptibility to infection, water vapor loss and associated shrinkage, roughened and cracked tuber surfaces, and various related blemishes and defects. PE results in aberra...

  15. Using Eye Tracking to Understand the Responses of Learners to Vocabulary Learning Strategy Instruction and Use

    Science.gov (United States)

    Liu, Pei-Lin

    2014-01-01

    This study examined the influence of morphological instruction in an eye-tracking English vocabulary recognition task. Sixty-eight freshmen enrolled in an English course and received either traditional or morphological instruction for learning English vocabulary. The experimental part of the study was conducted over two-hour class periods for…

  16. Healthy Eyes

    Science.gov (United States)

    ... los Ojos Cómo hablarle a su oculista Healthy Eyes Having a comprehensive dilated eye exam is one ... or contact lenses. What is a comprehensive dilated eye exam? A comprehensive dilated eye exam is a ...

  17. Inverse U-shaped curve for age dependency of torsional eye movement responses to galvanic vestibular stimulation.

    Science.gov (United States)

    Jahn, Klaus; Naessl, Andrea; Schneider, Erich; Strupp, Michael; Brandt, Thomas; Dieterich, Marianne

    2003-07-01

    To investigate age dependent changes we analysed torsional eye movement responses to binaural and monaural galvanic vestibular stimulation (GVS) in 57 healthy subjects (20-69 years old). GVS (1-3 mA) induced torsional eye movements consisting of static torsion toward the anode (amplitude 1-6 degrees ) and superimposed torsional nystagmus (slow phase velocity 0.5-3 degrees /s, quick phase amplitude 0.5-2 degrees, nystagmus frequency 0.75-1.5 s-1). Static ocular torsion and torsional nystagmus increased from the third to the sixth decade and decreased in older subjects, e.g. slow phase velocity increased from 1.5 degrees /s (20-29 years) to 2.9 degrees /s (50-59 years) and decreased to 2.5 degrees /s for the seventh decade (60-69 years). Thus, an inverse U-shaped curve was found for the dependence of torsional eye movement responses on age. All structures relevant for vestibular function degenerate with age, but at varying times. Since hair cell loss precedes those seen in the vestibular nerve and Scarpa's ganglion, the decrease in hair cell counts could be compensated for by increased sensitivity of afferent nerve fibres or central mechanisms. Increased sensitivity could thus maintain normal function despite reduced peripheral input. As GVS acts at the vestibular nerve (thereby bypassing the hair cells), electrical stimulation should be more efficient in subjects with the beginning of hair cell degeneration, as seen in our data up to the sixth decade. The degeneration of nerve fibres, ganglion cells and central neurons becomes evident at older ages. Thus, the compensatory increase in sensitivity breaks down and GVS-induced eye movements decline-a finding that is reflected by the inverse U-shaped curve for age dependency presented in this study.

  18. Non-blinking semiconductor colloidal quantum dots for biology, optoelectronics and quantum optics.

    Science.gov (United States)

    Spinicelli, Piernicola; Mahler, Benoit; Buil, Stéphanie; Quélin, Xavier; Dubertret, Benoit; Hermier, Jean-Pierre

    2009-04-14

    Twinkle, twinkle: The blinking of semiconductor colloidal nanocrystals is the main inconvenience of these bright nanoemitters. There are various approaches for obtaining non-blinking nanocrystals, one of which is to grow a thick coat of CdS on the CdSe core (see picture). Applications of this method in the fields of optoelectronic devices, biologic labelling and quantum information processing are discussed.The blinking of semiconductor colloidal nanocrystals is the main inconvenience of these bright nanoemitters. For some years, research on this phenomenon has demonstrated the possibility to progress beyond this problem by suppressing this fluorescence intermittency in various ways. After a brief overview on the microscopic mechanism of blinking, we review the various approaches used to obtain non-blinking nanocrystals and discuss the commitment of this crucial improvement to applications in the fields of optoelectronic devices, biologic labelling and quantum information processing.

  19. Distractor Inhibition Predicts Individual Differences in the Attentional Blink

    OpenAIRE

    Dux, Paul E.; René Marois

    2008-01-01

    BACKGROUND: The attentional blink (AB) refers to humans' impaired ability to detect the second of two targets (T2) in a rapid serial visual presentation (RSVP) stream of distractors if it appears within 200-600 ms of the first target (T1). Here we examined whether humans' ability to inhibit distractors in the RSVP stream is a key determinant of individual differences in T1 performance and AB magnitude. METHODOLOGY/PRINCIPAL FINDINGS: We presented subjects with RSVP streams (93.3 ms/item) of l...

  20. Camera vibration measurement using blinking light-emitting diode array.

    Science.gov (United States)

    Nishi, Kazuki; Matsuda, Yuichi

    2017-01-23

    We present a new method for measuring camera vibrations such as camera shake and shutter shock. This method successfully detects the vibration trajectory and transient waveforms from the camera image itself. We employ a time-varying pattern as the camera test chart over the conventional static pattern. This pattern is implemented using a specially developed blinking light-emitting-diode array. We describe the theoretical framework and pattern analysis of the camera image for measuring camera vibrations. Our verification experiments show that our method has a detection accuracy and sensitivity of 0.1 pixels, and is robust against image distortion. Measurement results of camera vibrations in commercial cameras are also demonstrated.

  1. Response of eyes with age-related macular degeneration to anti-VEGF drugs and implications for therapy planning

    Directory of Open Access Journals (Sweden)

    Miyamoto N

    2017-04-01

    Full Text Available Noriko Miyamoto,1,2 Michiko Mandai,1,3 Hiroshi Kojima,1,2 Takanori Kameda,1,2 Masataka Shimozono,1,2 Akihiro Nishida,1,2 Yasuo Kurimoto1,2 1Department of Ophthalmology, Kobe City Medical Center General Hospital, 2Department of Ophthalmology, Institute of Biomedical Research and Innovation, 3Laboratory for Retinal Regeneration, RIKEN Center for Developmental Biology, Kobe, Japan Purpose: To evaluate the response to and dependence on aflibercept or ranibizumab in patients with age-related macular degeneration (AMD.Methods: We retrospectively reviewed AMD patients who received induction therapy with aflibercept or ranibizumab for the following parameters: whether complete resolution of the retinal fluid (“good response” was achieved and whether recurrence was observed within 3 months (“dependent” after the induction treatment. With aflibercept treatment, treatment-naïve eyes with a good response/non-dependence were recommended a pro re nata regimen, and other eyes were recommended a proactive bimonthly regimen, followed by monitoring of visual acuity (VA for 12 months. The measured values of the groups were compared using one-way analysis of variance with Tukey’s test to evaluate the difference between baseline and postinjection VA.Results: Among the treatment-naïve eyes, 76% had a good response to aflibercept and 37% of these were aflibercept-dependent, while 58% had a good response to ranibizumab but 51% of these were ranibizumab-dependent. Among the eyes that converted from ranibizumab treatment, 92% of the good responders to ranibizumab with dependence and 76% of the poor responders on ranibizumab had a good response to aflibercept. With aflibercept treatment, the mean VA of treatment-naïve patients was significantly better than the baseline VA over 12 months (P<0.001, and the VA of the converted group improved significantly with proactive treatment and the improvement was continuously maintained from 6 to 12 months

  2. Behavioural and eye-movement outcomes in response to text-based reading treatment for acquired alexia.

    Science.gov (United States)

    Kim, Esther S; Lemke, Shannon F

    2016-01-01

    Text-based reading treatments, such as Multiple Oral Rereading (MOR) and Oral Reading for Language in Aphasia (ORLA) have been used successfully to remediate reading impairments in individuals with acquired alexia, but the mechanisms underlying such improvements are not well understood. In this study, an individual with acquired alexia who demonstrated reliance on a sub-lexical reading strategy (i.e., presence of spelling regularity effect and phonologically plausible errors) underwent 12 weeks of text-based reading treatment combining MOR and ORLA procedures. Behavioural assessments of single-word and text reading, along with eye-tracking assessments were conducted pre-treatment, post-treatment and at 5 month follow-up. Improved reading fluency (rate, accuracy) was observed for both trained and untrained passages. Evidence from behavioural and eye-tracking assessment suggested text-based reading treatment facilitated use of a lexical-semantic reading strategy. Increased frequency and lexicality effects, as well as a shift in initial landing position towards the centre of the word (the "optimal viewing position") were observed at post-treatment and follow-up assessments. These results demonstrate the potential utility of using eye movements as a parameter of interest in addition to traditional behavioural outcomes when investigating response to reading treatment.

  3. Psychophysiological Responsivity to Script-Driven Imagery: An Exploratory Study of the Effects of Eye Movements on Public Speaking Flashforwards.

    Science.gov (United States)

    Kearns, Michelle; Engelhard, Iris M

    2015-01-01

    A principle characteristic of public speaking anxiety relates to intrusive mental images of potential future disasters. Previous research has found that the self-reported emotionality of such "flashforwards" can be reduced by a cognitively demanding, dual-task (e.g., making eye movements) performed whilst holding the mental image in-mind. The outcome measure in these earlier studies was participants' self-reported emotional intensity of the mental image. The current study (N = 34) explored whether an objective measure of emotionality would yield similar results in students with public speaking anxiety. A script-driven imagery procedure was used to measure psychophysiological responsivity to an audio script depicting a feared (public speaking) scenario before and after an eye movement intervention. Relative to the control condition (imagery only), those who made eye movements whilst holding a mental image of this scenario in-mind demonstrated a significant decrease in heart rate, which acted as a measure of emotionality. These findings add to a previous body of research demonstrating the beneficial qualities of dual-tasks and their potential for treatment of both past and future-oriented anxieties.

  4. Neural Network Approach for Eye Detection

    CERN Document Server

    Vijayalaxmi,; Sreehari, S

    2012-01-01

    Driving support systems, such as car navigation systems are becoming common and they support driver in several aspects. Non-intrusive method of detecting Fatigue and drowsiness based on eye-blink count and eye directed instruction controlhelps the driver to prevent from collision caused by drowsy driving. Eye detection and tracking under various conditions such as illumination, background, face alignment and facial expression makes the problem complex.Neural Network based algorithm is proposed in this paper to detect the eyes efficiently. In the proposed algorithm, first the neural Network is trained to reject the non-eye regionbased on images with features of eyes and the images with features of non-eye using Gabor filter and Support Vector Machines to reduce the dimension and classify efficiently. In the algorithm, first the face is segmented using L*a*btransform color space, then eyes are detected using HSV and Neural Network approach. The algorithm is tested on nearly 100 images of different persons under...

  5. Management of the Eye in Facial Paralysis.

    Science.gov (United States)

    Chi, John J

    2016-02-01

    The preoperative assessment of the eye in facial paralysis is a critical component of surgical management. The degree of facial nerve paralysis, lacrimal secretion, corneal sensation, and lower eyelid position must be assessed accurately. Upper eyelid loading procedures are standard management of lagophthalmos. Lower eyelid tightening repositions the lower eyelid and helps maintain the aqueous tear film. Eyelid reanimation allows an aesthetic symmetry with blinking and restores protective functions vital to ocular preservation. Patients often have multiple nervous deficits, including corneal anesthesia. Other procedures include tarsorrhaphy, spring implantation, and temporalis muscle transposition; associated complications have rendered them nearly obsolete.

  6. Blinking in quantum dots: The origin of the grey state and power law statistics

    Science.gov (United States)

    Ye, Mao; Searson, Peter C.

    2011-09-01

    Quantum dot (QD) blinking is characterized by switching between an “on” state and an “off” state, and a power-law distribution of on and off times with exponents from 1.0 to 2.0. The origin of blinking behavior in QDs, however, has remained a mystery. Here we describe an energy-band model for QDs that captures the full range of blinking behavior reported in the literature and provides new insight into features such as the gray state, the power-law distribution of on and off times, and the power-law exponents.

  7. Hemodynamic responses of eye movement desensitization and reprocessing in posttraumatic stress disorder.

    Science.gov (United States)

    Ohtani, Toshiyuki; Ohta ni, Toshiyuki; Matsuo, Koji; Kasai, Kiyoto; Kato, Tadafumi; Kato, Nobumasa

    2009-12-01

    Eye movement desensitization and reprocessing (EMDR) is an effective psychological intervention for posttraumatic stress disorder (PTSD). Trauma-related recall (Recall) with eye movements (EMs) is thought to reduce distress. However, the neural mechanisms underlying this process remain unknown. Thirteen patients with PTSD received EMDR treatment over the course of 2-10 weeks. We assessed the change in hemoglobin concentration in the lateral prefrontal cortex (PFC) during Recall with and without EM using multi-channel near-infrared spectroscopy (NIRS). Clinical diagnosis and improvement were evaluated using the Clinician-Administered PTSD Scale. Recall with EM was associated with a significant decrease in oxygenated hemoglobin concentration ([oxy-Hb]) in the lateral PFC as compared with Recall without EM. Longitudinally, [oxy-Hb] during Recall significantly decreased and the amount of decrease was significantly correlated with clinical improvement when the post-treatment data was compared with that of the pre-treatment. Our results suggest that performing EM during Recall reduces the over-activity of the lateral PFC, which may be part of the biological basis for the efficacy of EMDR in PTSD. NIRS may be a useful tool for objective assessment of psychological intervention in PTSD.

  8. Exploring responses to art in adolescence: a behavioral and eye-tracking study.

    Science.gov (United States)

    Savazzi, Federica; Massaro, Davide; Di Dio, Cinzia; Gallese, Vittorio; Gilli, Gabriella; Marchetti, Antonella

    2014-01-01

    Adolescence is a peculiar age mainly characterized by physical and psychological changes that may affect the perception of one's own and others' body. This perceptual peculiarity may influence the way in which bottom-up and top-down processes interact and, consequently, the perception and evaluation of art. This study is aimed at investigating, by means of the eye-tracking technique, the visual explorative behavior of adolescents while looking at paintings. Sixteen color paintings, categorized as dynamic and static, were presented to twenty adolescents; half of the images represented natural environments and half human individuals; all stimuli were displayed under aesthetic and movement judgment tasks. Participants' ratings revealed that, generally, nature images are explicitly evaluated as more appealing than human images. Eye movement data, on the other hand, showed that the human body exerts a strong power in orienting and attracting visual attention and that, in adolescence, it plays a fundamental role during aesthetic experience. In particular, adolescents seem to approach human-content images by giving priority to elements calling forth movement and action, supporting the embodiment theory of aesthetic perception.

  9. Exploring responses to art in adolescence: a behavioral and eye-tracking study.

    Directory of Open Access Journals (Sweden)

    Federica Savazzi

    Full Text Available Adolescence is a peculiar age mainly characterized by physical and psychological changes that may affect the perception of one's own and others' body. This perceptual peculiarity may influence the way in which bottom-up and top-down processes interact and, consequently, the perception and evaluation of art. This study is aimed at investigating, by means of the eye-tracking technique, the visual explorative behavior of adolescents while looking at paintings. Sixteen color paintings, categorized as dynamic and static, were presented to twenty adolescents; half of the images represented natural environments and half human individuals; all stimuli were displayed under aesthetic and movement judgment tasks. Participants' ratings revealed that, generally, nature images are explicitly evaluated as more appealing than human images. Eye movement data, on the other hand, showed that the human body exerts a strong power in orienting and attracting visual attention and that, in adolescence, it plays a fundamental role during aesthetic experience. In particular, adolescents seem to approach human-content images by giving priority to elements calling forth movement and action, supporting the embodiment theory of aesthetic perception.

  10. EEG and Eye Tracking Demonstrate Vigilance Enhancement with Challenge Integration.

    Science.gov (United States)

    Bodala, Indu P; Li, Junhua; Thakor, Nitish V; Al-Nashash, Hasan

    2016-01-01

    Maintaining vigilance is possibly the first requirement for surveillance tasks where personnel are faced with monotonous yet intensive monitoring tasks. Decrement in vigilance in such situations could result in dangerous consequences such as accidents, loss of life and system failure. In this paper, we investigate the possibility to enhance vigilance or sustained attention using "challenge integration," a strategy that integrates a primary task with challenging stimuli. A primary surveillance task (identifying an intruder in a simulated factory environment) and a challenge stimulus (periods of rain obscuring the surveillance scene) were employed to test the changes in vigilance levels. The effect of integrating challenging events (resulting from artificially simulated rain) into the task were compared to the initial monotonous phase. EEG and eye tracking data is collected and analyzed for n = 12 subjects. Frontal midline theta power and frontal theta to parietal alpha power ratio which are used as measures of engagement and attention allocation show an increase due to challenge integration (p eye tracking data exhibit statistically significant changes during the challenge phase of the experiment (p eye tracking and EEG, we infer that saccade amplitude and saccade velocity decrease with vigilance decrement along with frontal midline theta and frontal theta to parietal alpha ratio. Conversely, blink rate and relative delta power increase with vigilance decrement. However, these measures exhibit a reverse trend when challenge stimulus appears in the task suggesting vigilance enhancement. Moreover, the mean reaction time is lower for the challenge integrated phase (RTmean = 3.65 ± 1.4s) compared to initial monotonous phase without challenge (RTmean = 4.6 ± 2.7s). Our work shows that vigilance level, as assessed by response of these vital signs, is enhanced by challenge integration.

  11. "Schizoid" personality in childhood: auditory P300 and eye tracking responses at follow-up in adult life.

    Science.gov (United States)

    Blackwood, D H; Muir, W J; Roxborough, H M; Walker, M R; Townshend, R; Glabus, M F; Wolff, S

    1994-08-01

    The auditory P300 response and smooth pursuit eye tracking were recorded from a group of 23 male adult subjects who had been diagnosed in childhood as having schizoid personality. No differences were found in these physiological measures between the study group, their matched controls of other child psychiatric patients, and a group of population controls. The essentially negative findings are discussed in the light of abnormalities of these psychophysiological responses previously found in schizophrenic patients, in some of their biological relatives, and in other groups of psychiatric patients, including autistic children and adults with a diagnosis of borderline and schizotypal personality disorder. Results suggest that "schizoid" children, despite their high scores on a measure of schizotypy, do not have schizophrenia spectrum disorder or that schizotypy is a heterogeneous condition.

  12. Eye Injuries

    Science.gov (United States)

    The structure of your face helps protect your eyes from injury. Still, injuries can damage your eye, sometimes severely enough that you could lose your vision. Most eye injuries are preventable. If you play sports or ...

  13. Eye Wear

    Science.gov (United States)

    Eye wear protects or corrects your vision. Examples are Sunglasses Safety goggles Glasses (also called eyeglasses) Contact ... jobs and some sports carry a risk of eye injury. Thousands of children and adults get eye ...

  14. Eye Cancer

    Science.gov (United States)

    Cancer of the eye is uncommon. It can affect the outer parts of the eye, such as the eyelid, which are made up ... adults are melanoma and lymphoma. The most common eye cancer in children is retinoblastoma, which starts in ...

  15. Eye Diseases

    Science.gov (United States)

    ... the back of the eye Macular degeneration - a disease that destroys sharp, central vision Diabetic eye problems ... defense is to have regular checkups, because eye diseases do not always have symptoms. Early detection and ...

  16. Non-blinking quantum dot with a plasmonic nanoshell resonator

    Science.gov (United States)

    Ji, Botao; Giovanelli, Emerson; Habert, Benjamin; Spinicelli, Piernicola; Nasilowski, Michel; Xu, Xiangzhen; Lequeux, Nicolas; Hugonin, Jean-Paul; Marquier, Francois; Greffet, Jean-Jacques; Dubertret, Benoit

    2015-02-01

    Colloidal semiconductor quantum dots are fluorescent nanocrystals exhibiting exceptional optical properties, but their emission intensity strongly depends on their charging state and local environment. This leads to blinking at the single-particle level or even complete fluorescence quenching, and limits the applications of quantum dots as fluorescent particles. Here, we show that a single quantum dot encapsulated in a silica shell coated with a continuous gold nanoshell provides a system with a stable and Poissonian emission at room temperature that is preserved regardless of drastic changes in the local environment. This novel hybrid quantum dot/silica/gold structure behaves as a plasmonic resonator with a strong Purcell factor, in very good agreement with simulations. The gold nanoshell also acts as a shield that protects the quantum dot fluorescence and enhances its resistance to high-power photoexcitation or high-energy electron beams. This plasmonic fluorescent resonator opens the way to a new family of plasmonic nanoemitters with robust optical properties.

  17. Filter Feeding, Chaotic Filtration, and a Blinking Stokeslet

    Science.gov (United States)

    Blake, J. R.; Otto, S. R.; Blake, D. A.

    The filtering mechanisms in bivalve molluscs, such as the mussel Mytilus edulis, and in sessile organisms, such as Vorticella or Stentor, involve complex fluid mechanical phenomena. In the former example, three different sets of cilia serving different functions are involved in the process whereas in the sessile organisms the flexibility and contractile nature of the stalk may play an important role in increasing the filtering efficiency of the organisms. In both cases, beating microscopic cilia are the ``engines'' driving the fluid motion, so the fluid mechanics will be dominated entirely by viscous forces. A fluid mechanical model is developed for the filtering mechanism in mussels that enables estimates to be made of the pressure drop through the gill filaments due to (i) latero-frontal filtering cilia, (ii) the lateral (pumping) cilia, and (iii) through the non-ciliated zone of the ventral end of the filament. The velocity profile across the filaments indicates that a backflow can occur in the centre of the channel leading to the formation of two ``standing'' eddies which may drive particles towards the mucus-laden short cilia, the third set of cilia. Filter feeding in the sessile organisms is modelled by a point force above a rigid boundary. The point force periodically changes its point of application according to a given protocol (a blinking stokeslet). The resulting fluid field is illustrated via Poincaré sections and particle dispersion-showing the potential for a much improved filtering efficiency. Returning to filter feeding in bivalve molluscs, this concept is extended to a pair of blinking stokeslets above a rigid boundary to give insight into possible mechanisms for movement of food particles onto the short mucus-bearing cilia. The appendix contains a Latin and English version of an ``Ode of Achievement'' in celebration of Sir James Lighthill's contributions to mathematics and fluid mechanics.

  18. The influence of training on the attentional blink and psychological refractory period.

    Science.gov (United States)

    Garner, K G; Tombu, M N; Dux, P E

    2014-05-01

    A growing body of research suggests that dual-task interference in sensory consolidation (e.g., the attentional blink, AB) and response selection (e.g., the psychological refractory period, PRP) stems from a common central bottleneck of information processing. With regard to response selection, it is well known that training reduces dual-task interference. We tested whether training that is known to be effective for response selection can also reduce dual-task interference in sensory consolidation. Over two experiments, performance on a PRP paradigm (Exp. 1) and on AB paradigms (differing in their stimuli and task demands, Exps. 1 and 2) was examined after participants had completed a relevant training regimen (T1 practice for both paradigms), an irrelevant training regimen (comparable sensorimotor training, not related to T1 for both tasks), a visual-search training regimen (Exp. 2 only), or after participants had been allocated to a no-training control group. Training that had shown to be effective for reducing dual-task interference in response selection was also found to be effective for reducing interference in sensory consolidation. In addition, we found some evidence that training benefits transferred to the sensory consolidation of untrained stimuli. Collectively, these findings show that training benefits can transfer across cognitive operations that draw on the central bottleneck in information processing. These findings have implications for theories of the AB and for the design of cognitive-training regimens that aim to produce transferable training benefits.

  19. Coping with the Green-Eyed Monster: Conceptualizing and Measuring Communicative Responses to Romantic Jealousy.

    Science.gov (United States)

    Guerrero, Laura K.; And Others

    1995-01-01

    Examines communicative responses to romantic jealousy. Finds 12 superordinate categories and 67 tactics in communicative responses to jealousy. Develops measures for six types of interactive responses (integrative communication, distributive communication, active distancing, general avoidance/denial, expression of negative affect, and violent…

  20. Use of postmortem temperature decay response surface plots of heat transport in the human eye to predict time of death.

    Science.gov (United States)

    Smart, Jimmy L

    2014-03-01

    A finite element heat transfer model of the human eye was previously constructed and applied to experimental postmortem temperature decay curves collected in eyeballs of ten human bodies. The model was applied in the early postmortem period of 0–24 h under conditions of natural convection–radiation. Based upon this previous model, response surfaces for postmortem temperature decay were constructed based upon variable ranges of the natural convective–radiation heat transfer coefficient from 7–13 W/m2 K, ambient temperatures of 10–33°C, and times of 0–24 h. Mathematical equations to describe these response surfaces have been developed. This response surface method is demonstrated for use by coroners/medical personnel to estimate time of death from recorded field temperature data collected over a 30-min period. Sensitivity of the model to small changes in the key variable of ambient temperature is explored. The response surface model is applied to two cases of previously collected experimental eyeball temperature data. This response surface model method is only valid for constant surrounding temperatures, conditions of natural convection, no radiation effects, and postmortem times of 0–24 h.

  1. Elevated hormonal stress response and reduced reproductive output in Yellow-eyed penguins exposed to unregulated tourism.

    Science.gov (United States)

    Ellenberg, Ursula; Setiawan, Alvin N; Cree, Alison; Houston, David M; Seddon, Philip J

    2007-05-15

    The endangered, endemic Yellow-eyed penguin (Megadyptes antipodes) is one of the flagship species for New Zealand's wildlife tourism, and recently concern has been raised that tourism-related pressures may be becoming too great. We compared two neighbouring breeding areas exposed to different levels of human disturbance. Penguins at the site exposed to unregulated tourism showed significantly lower breeding success and fledging weights than those in an area visited infrequently for monitoring purposes only. High parental baseline corticosterone concentrations correlated with lower fledgling weights at both sites. Stress-induced corticosterone concentrations were significantly higher at the tourist-exposed site, suggesting birds have been sensitized by frequent disturbance. Consequences are likely to include reduced juvenile survival and recruitment to the tourist site, while the changed hormonal stress responses may ultimately have an effect on adult fitness and survival. For maintenance of attractive Yellow-eyed penguin-viewing destinations we recommend that tourists stay out of breeding areas and disturbance at penguin landing beaches is reduced.

  2. Time course of superior temporal sulcus activity in response to eye gaze: a combined fMRI and MEG study

    Science.gov (United States)

    Kochiyama, Takanori; Uono, Shota; Yoshikawa, Sakiko

    2008-01-01

    The human superior temporal sulcus (STS) has been suggested to be involved in gaze processing, but temporal data regarding this issue are lacking. We investigated this topic by combining fMRI and MEG in four normal subjects. Photographs of faces with either averted or straight eye gazes were presented and subjects passively viewed the stimuli. First, we analyzed the brain areas involved using fMRI. A group analysis revealed activation of the STS for averted compared to straight gazes, which was confirmed in all subjects. We then measured brain activity using MEG, and conducted a 3D spatial filter analysis. The STS showed higher activity in response to averted versus straight gazes during the 150–200 ms period, peaking at around 170 ms, after stimulus onset. In contrast, the fusiform gyrus, which was detected by the main effect of stimulus presentations in fMRI analysis, exhibited comparable activity across straight and averted gazes at about 170 ms. These results indicate involvement of the human STS in rapid processing of the eye gaze of another individual. PMID:19015114

  3. Effect of X-ray irradiation on the blinking of single silicon nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Pevere, Federico; Bruhn, Benjamin; Sangghaleh, Fatemeh; Hormozan, Yashar; Sychugov, Ilya; Linnros, Jan [Material and Nano Physics Department, ICT School, KTH Royal Institute of Technology, Kista (Sweden)

    2015-12-15

    Photoluminescence (PL) intermittency (blinking) observed for single silicon nanocrystals (Si-NCs) embedded in oxide is usually attributed to trapping/de-trapping of carriers in the vicinity of the NC. Following this model, we propose that blinking could be modified by introducing new trap sites, for example, via X-rays. In this work, we present a study of the effect of X-ray irradiation (up to 65 kGy in SiO{sub 2}) on the blinking of single Si-NCs embedded in oxide nanowalls. We show that the luminescence characteristics, such as spectrum and life-time, are unaffected by X-rays. However, substantial changes in ON-state PL intensity, switching frequency, and duty cycle emerge from the blinking traces, while the ON- and OFF- time distributions remain of mono-exponential character. Although we do not observe a clear monotonic dependence of the blinking parameters on the absorbed dose, our study suggests that, in the future, Si-NCs could be blinking-engineered via X-ray irradiation. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  4. Comparison of topical dry eye medications for the treatment of keratoconjunctivitis sicca in a botulinum toxin B-induced mouse model.

    Science.gov (United States)

    Lekhanont, Kaevalin; Leyngold, Ilya M; Suwan-Apichon, Olan; Rangsin, Ram; Chuck, Roy S

    2007-01-01

    To compare the effects of topical dry eye medications including anti-inflammatory agents and lubricant eyedrops for the treatment of keratoconjunctivitis sicca (KCS) in a botulinum toxin B (BTX-B)-induced mouse model. CBA mice were randomized into 10 groups. The first 5 groups received a transconjunctival injection of saline into the lacrimal gland, and the remaining groups were injected with 0.05 mL of 20 mU BTX-B. Each group received treatment with 0.1% fluorometholone (FML), 0.05% cyclosporine A (CsA), a 50:50 combination of FML and CsA, artificial tears, or saline 3 days after injections. Tear production, corneal staining, and blink rate were compared in each of the 10 groups. Tear production in BTX-B-injected CsA-treated, FML-treated, and combined-treated groups started to return to baseline level within 2 weeks of treatment, whereas those treated with saline or artificial tears still exhibited reduction of lacrimation up to 4 weeks after injection. Topical FML significantly reversed the staining score within 1 week of treatment. The improvement of corneal staining in BTX-B-challenged combined-treated and CsA-treated groups occurred later within 2 weeks after treatment. No significant improvement in corneal staining was observed for the BTX-B-injected mice treated with artificial tears or saline. No significant changes were noted in blink frequency between the control and study groups undergoing the various dry eye therapies. The therapeutic effects of dry eye medications in a BTX-B-induced mouse model of KCS are similar to the human response.

  5. A Removal of Eye Movement and Blink Artifacts from EEG Data Using Morphological Component Analysis

    Science.gov (United States)

    Wagatsuma, Hiroaki

    2017-01-01

    EEG signals contain a large amount of ocular artifacts with different time-frequency properties mixing together in EEGs of interest. The artifact removal has been substantially dealt with by existing decomposition methods known as PCA and ICA based on the orthogonality of signal vectors or statistical independence of signal components. We focused on the signal morphology and proposed a systematic decomposition method to identify the type of signal components on the basis of sparsity in the time-frequency domain based on Morphological Component Analysis (MCA), which provides a way of reconstruction that guarantees accuracy in reconstruction by using multiple bases in accordance with the concept of “dictionary.” MCA was applied to decompose the real EEG signal and clarified the best combination of dictionaries for this purpose. In our proposed semirealistic biological signal analysis with iEEGs recorded from the brain intracranially, those signals were successfully decomposed into original types by a linear expansion of waveforms, such as redundant transforms: UDWT, DCT, LDCT, DST, and DIRAC. Our result demonstrated that the most suitable combination for EEG data analysis was UDWT, DST, and DIRAC to represent the baseline envelope, multifrequency wave-forms, and spiking activities individually as representative types of EEG morphologies. PMID:28194221

  6. Jealousy in the blink of an eye : Jealous reactions following subliminal exposure to rival characteristics

    NARCIS (Netherlands)

    Massar, Karlijn; Buunk, Abraham P.; Dechesne, Mark

    In the present experiment it was investigated whether the evaluation of rivals could be all unconscious process, engaged in automatically whenever a rival is present. To this end, participants were subliminally primed. with words relating to rival characteristics after which the), read a jealousy

  7. A Removal of Eye Movement and Blink Artifacts from EEG Data Using Morphological Component Analysis

    Directory of Open Access Journals (Sweden)

    Balbir Singh

    2017-01-01

    Full Text Available EEG signals contain a large amount of ocular artifacts with different time-frequency properties mixing together in EEGs of interest. The artifact removal has been substantially dealt with by existing decomposition methods known as PCA and ICA based on the orthogonality of signal vectors or statistical independence of signal components. We focused on the signal morphology and proposed a systematic decomposition method to identify the type of signal components on the basis of sparsity in the time-frequency domain based on Morphological Component Analysis (MCA, which provides a way of reconstruction that guarantees accuracy in reconstruction by using multiple bases in accordance with the concept of “dictionary.” MCA was applied to decompose the real EEG signal and clarified the best combination of dictionaries for this purpose. In our proposed semirealistic biological signal analysis with iEEGs recorded from the brain intracranially, those signals were successfully decomposed into original types by a linear expansion of waveforms, such as redundant transforms: UDWT, DCT, LDCT, DST, and DIRAC. Our result demonstrated that the most suitable combination for EEG data analysis was UDWT, DST, and DIRAC to represent the baseline envelope, multifrequency wave-forms, and spiking activities individually as representative types of EEG morphologies.

  8. 眨眼检测与眼睛跟踪%Blink detection and eye tracking

    Institute of Scientific and Technical Information of China (English)

    刘瑞安; 靳世久; 张希坤; 宋维; 吴晓荣

    2006-01-01

    提出一种在视频人脸图像序列中,进行眼睛检测,跟踪和睁、闭状态判别的方法.通过眨眼检测,对眼睛进行定位;使用针对性强的内眼角提取算子,确定内眼角精确位置;利用内眼角特征来动态跟踪眼睛;睁眼模板在线生成和更新,通过当前眼睛区域和睁眼模板的相关分析来判别睁、闭眼状态.实验结果表明,算法在50场/s的处理速度下,内眼角点定位准确率达到98%以上,眨眼检测正确率为97.5%.

  9. Survival and physiologic response of Common Amakihi and Japanese White-eyes during simulated translocation

    Science.gov (United States)

    Work, T.M.; Massey, J.G.; Johnson, L.; Dougill, S.; Banko, P.C.

    1999-01-01

    We evaluated the effects of three translocation trials on Common Amakihi (Hemignathus virens) and Japanese White-eyes (Zosterops japonicus). Trial 1 involved capturing birds, transporting them on rough roads for 4 hr followed by holding in an aviary for 48 hr without overnight thermal support prior to release. Trial 2 involved capture, then holding in an aviary for 48 hr with overnight thermal support followed by transport for 4 hr prior to release. Trial 3 and 1 were identical except that overnight thermal support was provided during trial 3. We monitored survival, food consumption, weight change, and fecal production during captivity as well as changes in hematocrit, estimated total solids, heterophil to lymphocyte ratios, plasma uric acid, and creatinine phosphokinase (CPK) at capture and release. Survival was significantly lower for Amakihi during trial I (no thermal support). Birds that died lost significantly more weight than those that survived. Regardless of trial, birds responded to translocation by a combination of weight loss, anemia, hypoproteinemia, and elevated heterophil to lymphocyte ratio, uric acid, and CPK levels. The first 24 hr of captivity posed the greatest risk to birds regardless of whether transport or holding occurred first. Food consumption, fecal production, and weight all decreased at night, and overnight thermal support during holding was critical if ambient temperatures dipped to freezing. We recommend that if small passerines are to be held for > 12 hr, they be monitored individually for weight loss, food consumption, and fecal production.

  10. Ab interno trabeculectomy: ultrastructural evidence and early tissue response in a human eye.

    Science.gov (United States)

    Ferrari, Ettore; Ortolani, Fulvia; Petrelli, Lucia; Contin, Magali; Pognuz, Derri Roman; Marchini, Maurizio; Bandello, Francesco

    2007-10-01

    To report the results of ultrastructural analysis of the postoperative effects of ab interno trabeculectomy in a human eye. Department of Ophthalmology, Palmanova Hospital, Palmanova, Udine, Italy. A 60-year-old woman with cataract and glaucoma had enucleation for a choroidal melanoma 10 days after ab interno trabeculectomy combined with phacoemulsification. A second ab interno trabeculectomy was performed after enucleation to evaluate the outcomes of the previous trabeculectomy. Light and transmission electron microscopy analyses were performed on samples excised from areas (1) not subjected to a procedure (control samples), (2) that had ab interno trabeculectomy before enucleation, and (3) that had ab interno trabeculectomy immediately after enucleation. Control samples showed normal trabecular features. Semithin sections of all ab interno trabeculectomy samples showed full-thickness removal of trabeculum segments, with Schlemm's canal lumen opening into the anterior chamber and apparent preservation of the adjacent structures. On ultrathin sections of samples that had ab interno trabeculectomy before enucleation, the endothelium lining the outer wall of Schlemm's canal and other angle components showed intact ultrastructural features. In trabecular beams that were not removed, the extracellular matrix appeared to have maintained its fine texture and was free of activated fibroblasts or leucocyte infiltrates. Observations confirm that ab interno trabeculectomy causes direct communication between Schlemm's canal lumen and the anterior chamber in vivo and immediately after enucleation during the early postoperative period. The absence of an evident inflammatory reaction in the examined case should be considered with caution because of possible tumor-induced immune suppression.

  11. Response mode, compatibility, and dual-processes in the evaluation of simple gambles: An eye-tracking investigation

    Directory of Open Access Journals (Sweden)

    Paul Slovic

    2012-07-01

    Full Text Available We employed simple gambles to investigate information processing in relation to the compatibility effect. Subjects should be more likely to engage in a deliberative thinking strategy when completing a pricing task rather than a rating task. We used eye-tracking methodology to measure information acquisition and processing in order to test the above hypothesis as well as to show that losses and alternatives with uncertain outcomes are more likely than gains and alternatives with sure outcomes to be processed through a deliberative thinking process. Results showed that pupil dilations, fixation duration and number of fixations increased when subjects evaluated the gambles with a pricing task. Additionally, the number of fixations increased as the gamble outcome became increasingly negative and when the outcome was uncertain (vs. sure. Fixations were also predictive of subjects' final evaluations of the gambles. We discuss our results in light of the cognitive processes underlying different response modes in economic preferences.

  12. Effect of virtual image projection distance on the accomodative response of the eye.

    Science.gov (United States)

    Chisum, G T; Morway, P E

    1977-09-01

    Virtual image displays utilize either aircraft-mounted or helmet-mounted beam splitters, or combining screens. The effect on the accomodative response of the projection distance of the virtual image was measured by photographing the first and fourth Purkinje images of a source. The results indicate possible effect on the accomodation response. Further exploration of the problem is indicated.

  13. A proposed model of the response of the anophthalmic socket to prosthetic eye wear and its application to the management of mucoid discharge.

    Science.gov (United States)

    Pine, Keith R; Sloan, Brian H; Jacobs, Robert J

    2013-08-01

    Mucoid discharge associated with prosthetic eye wear can be a distressing condition that affects the quality of life of people who have lost an eye. Discharge is the second highest concern of experienced prosthetic eye wearers after health of the companion eye and is prevalent in anophthalmic populations. Specific causes of mucoid discharge such as infections and environmental allergens are well understood, but non-specific causes are unknown and an evidence based protocol for managing non-specific discharge is lacking. Current management is based on prosthesis removal and cleaning, and professional re-polishing of the prosthesis. Tear protein deposits accumulate on prosthetic eyes. These deposits mediate the response of the socket to prosthetic eye wear and their influence (good and bad) is determined by differing cleaning regimes and standards of surface finish. This paper proposes a three-phase model that describes the response of the socket to prosthetic eye wear. The phases are: An initial period of wear of a new (or newly-polished) prosthesis when homeostasis is being established (or re-established) within the socket; a second period (equilibrium phase) where beneficial surface deposits have built up on the prosthesis and wear is safe and comfortable, and a third period (breakdown phase) where there is an increasing likelihood of harm from continued wear. The proposed model provides a rationale for a personal cleaning regime to manage non-specific mucoid discharge. Professional care of prosthetic eyes is also important for the management of discharge and evidence for effective surface finishing is reported in this study. Taken together, the proposed regimes for personal and professional care comprise a protocol for managing discharge associated with prosthetic eye wear. The protocol describes prosthetic eye cleaning methods and frequency, and suggests minimum standards for professional polishing. If confirmed, the protocol has the potential to resolve the

  14. Whole exome sequencing implicates eye development, the unfolded protein response and plasma membrane homeostasis in primary open-angle glaucoma

    Science.gov (United States)

    Souzeau, Emmanuelle; Sharma, Shiwani; Landers, John; Mills, Richard; Goldberg, Ivan; Healey, Paul R.; Graham, Stuart; Hewitt, Alex W.; Mackey, David A.; Galanopoulos, Anna; Casson, Robert J.; Ruddle, Jonathan B.; Ellis, Jonathan; Leo, Paul; Brown, Matthew A.; MacGregor, Stuart; Lynn, David J.; Burdon, Kathryn P.; Craig, Jamie E.

    2017-01-01

    Purpose To identify biological processes associated with POAG and its subtypes, high-tension (HTG) and normal-tension glaucoma (NTG), by analyzing rare potentially damaging genetic variants. Methods A total of 122 and 65 unrelated HTG and NTG participants, respectively, with early onset advanced POAG, 103 non-glaucoma controls and 993 unscreened ethnicity-matched controls were included in this study. Study participants without myocilin disease-causing variants and non-glaucoma controls were subjected to whole exome sequencing on an Illumina HiSeq2000. Exomes of participants were sequenced on an Illumina HiSeq2000. Qualifying variants were rare in the general population (MAF < 0.001) and potentially functionally damaging (nonsense, frameshift, splice or predicted pathogenic using SIFT or Polyphen2 software). Genes showing enrichment of qualifying variants in cases were selected for pathway and network analysis using InnateDB. Results POAG cases showed enrichment of rare variants in camera-type eye development genes (p = 1.40×10–7, corrected p = 3.28×10–4). Implicated eye development genes were related to neuronal or retinal development. HTG cases were significantly enriched for key regulators in the unfolded protein response (UPR) (p = 7.72×10–5, corrected p = 0.013). The UPR is known to be involved in myocilin-related glaucoma; our results suggest the UPR has a role in non-myocilin causes of HTG. NTG cases showed enrichment in ion channel transport processes (p = 1.05×10–4, corrected p = 0.027) including calcium, chloride and phospholipid transporters involved in plasma membrane homeostasis. Network analysis also revealed enrichment of the MHC Class I antigen presentation pathway in HTG, and the EGFR1 and cell-cycle pathways in both HTG and NTG. Conclusion This study suggests that mutations in eye development genes are enriched in POAG. HTG can result from aberrant responses to protein misfolding which may be amenable to molecular chaperone therapy. NTG

  15. Mental Fatigue Monitoring Using a Wearable Transparent Eye Detection System

    Directory of Open Access Journals (Sweden)

    Kota Sampei

    2016-01-01

    Full Text Available We propose mental fatigue measurement using a wearable eye detection system. The system is capable of acquiring movement of the pupil and blinking from the light reflected from the eye. The reflection is detected by dye-sensitized photovoltaic cells. Since these cells are patterned onto the eyeglass and do not require external input power, the system is notable for its lightweight and low power consumption and can be combined with other wearable devices, such as a head mounted display. We performed experiments to correlate information obtained by the eye detection system with the mental fatigue of the user. Since it is quite difficult to evaluate mental fatigue objectively and quantitatively, we assumed that the National Aeronautics and Space Administration Task Load Index (NASA-TLX had a strong correlation with te mental fatigue. While a subject was requested to conduct calculation tasks, the eye detection system collected his/her information that included position, velocity and total movement of the eye, and amount and frequency of blinking. Multiple regression analyses revealed the correlation between NASA-TLX and the information obtained for 3 out of 5 subjects.

  16. The eye is listening: Music-induced arousal and individual differences predict pupillary responses

    Directory of Open Access Journals (Sweden)

    Bruno eGingras

    2015-11-01

    Full Text Available Pupillary responses are a well-known indicator of emotional arousal but have not yet been systematically investigated in response to music. Here, we measured pupillary dilations evoked by short musical excerpts normalized for intensity and selected for their stylistic uniformity. Thirty participants (15 females provided subjective ratings of music-induced felt arousal, tension, pleasantness and familiarity for 80 classical music excerpts. The pupillary responses evoked by these excerpts were measured in another thirty participants (15 females. We probed the role of listener-specific characteristics such as mood, stress reactivity, self-reported role of music in life, liking for the selected excerpts, as well as of subjective responses to music, in pupillary responses. Linear mixed model analyses showed that a greater role of music in life was associated with larger dilations, and that larger dilations were also predicted for excerpts rated as more arousing or tense. However, an interaction between arousal and liking for the excerpts suggested that pupillary responses were modulated less strongly by arousal when the excerpts were particularly liked. An analogous interaction was observed between tension and liking. Additionally, males exhibited larger dilations than females. Overall, these findings suggest a complex interplay between bottom-up and top-down influences on pupillary responses to music.

  17. BARRIERS RESPONSIBLE FOR DELAYED UTILIZATION OF CATARACT SURGERY: AN EYE CAMP STUDY FROM CENTRAL INDIA

    Directory of Open Access Journals (Sweden)

    Umesh

    2014-03-01

    Full Text Available INTRODUCTION: Blindness is one of the significant social problems in India with 7 million of the total 45 million blind people in the world residing in our country. Apart from health and status of vision, there are many other socio-economic factors and perceptions, which influence the decision making of the people for getting operated for cataract. But very few studies have been done on the social factors influencing the utilization of cataract surgery. MATERIAL AND METHODS: It was a hospital-based, descriptive study. The study subjects were recruited from the Ophthalmology department from cataract camp held in Chirayu medical College, Hospital during October 2013 to January 2014. RESULTS: In present study, insufficient family income and no one to accompany (60% and 10% was responded by majority of the subjects. In present study, the barriers for delayed utilization of cataract surgery like could manage to do daily work was responded by 513 (85.5% out of total 600 subjects, could see with the other eye clearly 470 (78.3%, busy with work 118 (19.6%, being female70 (11.6%, fear of surgery 115 (19.1%, old age 200 (33.3%, fear that surgery could lead to loss of eyesight 55 (9.1%, it was Gods will 35 (5.8%, fear about the cost of surgery 375 (62.5% and fear that surgery could lead to death was responded by 15 (2.5% out of total 600 subjects. CONCLUSION: Expansion of outreach programmes to different communities rather than concentrate in urban areas, and offering cataract surgical services at affordable rates will also be of help. Health Education has a great role to play as well, especially in creating awareness. Adequate dissemination of information through various media is usually will be very helpful

  18. The interblink interval in normal and dry eye subjects

    Directory of Open Access Journals (Sweden)

    Johnston PR

    2013-02-01

    Full Text Available Patrick R Johnston,1 John Rodriguez,1 Keith J Lane,1 George Ousler,1 Mark B Abelson1,21Ora, Inc, Andover, MA, USA; 2Schepens Eye Research Institute and Harvard Medical School, Boston, MA, USAPurpose: Our aim was to extend the concept of blink patterns from average interblink interval (IBI to other aspects of the distribution of IBI. We hypothesized that this more comprehensive approach would better discriminate between normal and dry eye subjects.Methods: Blinks were captured over 10 minutes for ten normal and ten dry eye subjects while viewing a standardized televised documentary. Fifty-five blinks were analyzed for each of the 20 subjects. Means, standard deviations, and autocorrelation coefficients were calculated utilizing a single random effects model fit to all data points and a diagnostic model was subsequently fit to predict probability of a subject having dry eye based on these parameters.Results: Mean IBI was 5.97 seconds for normal versus 2.56 seconds for dry eye subjects (ratio: 2.33, P = 0.004. IBI variability was 1.56 times higher in normal subjects (P < 0.001, and the autocorrelation was 1.79 times higher in normal subjects (P = 0.044. With regard to the diagnostic power of these measures, mean IBI was the best dry eye versus normal classifier using receiver operating characteristics (0.85 area under curve (AUC, followed by the standard deviation (0.75 AUC, and lastly, the autocorrelation (0.63 AUC. All three predictors combined had an AUC of 0.89. Based on this analysis, cutoffs of ≤3.05 seconds for median IBI, and ≤0.73 for the coefficient of variation were chosen to classify dry eye subjects.Conclusion: (1 IBI was significantly shorter for dry eye patients performing a visual task compared to normals; (2 there was a greater variability of interblink intervals in normal subjects; and (3 these parameters were useful as diagnostic predictors of dry eye disease. The results of this pilot study merit investigation of IBI

  19. Provider Behavior Under Global Budgeting and Policy Responses: An Observational Study on Eye Care Services in Taiwan.

    Science.gov (United States)

    Chang, Chao-Kai; Xirasagar, Sudha; Chen, Brian; Hussey, James R; Wang, I-Jong; Chen, Jen-Chieh; Lian, Ie-Bin

    2015-01-01

    Third-party payer systems are consistently associated with health care cost escalation. Taiwan's single-payer, universal coverage National Health Insurance (NHI) adopted global budgeting (GB) to achieve cost control. This study captures ophthalmologists' response to GB, specifically service volume changes and service substitution between low-revenue and high-revenue services following GB implementation, the subsequent Bureau of NHI policy response, and the policy impact. De-identified eye clinic claims data for the years 2000, 2005, and 2007 were analyzed to study the changes in Simple Claim Form (SCF) claims versus Special Case Claims (SCCs). The 3 study years represent the pre-GB period, post-GB but prior to region-wise service cap implementation period, and the post-service cap period, respectively. Repeated measures multilevel regression analysis was used to study the changes adjusting for clinic characteristics and competition within each health care market. SCF service volume (low-revenue, fixed-price patient visits) remained constant throughout the study period, but SCCs (covering services involving variable provider effort and resource use with flexibility for discretionary billing) increased in 2005 with no further change in 2007. The latter is attributable to a 30% cap negotiated by the NHI Bureau with the ophthalmology association and enforced by the association. This study demonstrates that GB deployed with ongoing monitoring and timely policy responses that are designed in collaboration with professional stakeholders can contain costs in a health insurance-financed health care system. © The Author(s) 2015.

  20. Aging: A Predisposition to Dry Eyes

    Directory of Open Access Journals (Sweden)

    Anushree Sharma

    2014-01-01

    Full Text Available Dry eye syndrome is a disease of the ocular surface and tear film that is prevalent in older adults. Even though the degree of visual acuity loss in dry eye patients is commonly mild-to-moderate, in the aging population, this minimal change in visual status can lead to a significant decrease in visual function and quality of life. A healthy ocular surface is maintained by appropriate tear production and tear drainage, and deficiencies in this delicate balance can lead to dryness. In the aging eye, risk factors such as polypharmacy, androgen deficiency, decreased blink rates, and oxidative stress can predispose the patient to developing dry eye that is frequently more severe, has higher economic costs, and leads to worse consequences to the well-being of the patient. Understanding why elderly patients are at higher risk for developing dry eyes can provide insights into the diagnosis and management of the growing number of older adults struggling with dry eye and minimize the burden of disease on our aging population.

  1. Facial expression influences face identity recognition during the attentional blink.

    Science.gov (United States)

    Bach, Dominik R; Schmidt-Daffy, Martin; Dolan, Raymond J

    2014-12-01

    Emotional stimuli (e.g., negative facial expressions) enjoy prioritized memory access when task relevant, consistent with their ability to capture attention. Whether emotional expression also impacts on memory access when task-irrelevant is important for arbitrating between feature-based and object-based attentional capture. Here, the authors address this question in 3 experiments using an attentional blink task with face photographs as first and second target (T1, T2). They demonstrate reduced neutral T2 identity recognition after angry or happy T1 expression, compared to neutral T1, and this supports attentional capture by a task-irrelevant feature. Crucially, after neutral T1, T2 identity recognition was enhanced and not suppressed when T2 was angry-suggesting that attentional capture by this task-irrelevant feature may be object-based and not feature-based. As an unexpected finding, both angry and happy facial expressions suppress memory access for competing objects, but only angry facial expression enjoyed privileged memory access. This could imply that these 2 processes are relatively independent from one another.

  2. Design of a computer game using an eye-tracking device for eye's activity rehabilitation

    Science.gov (United States)

    Lin, Chern-Sheng; Huan, Chia-Chin; Chan, Chao-Ning; Yeh, Mau-Shiun; Chiu, Chuang-Chien

    2004-07-01

    An eye mouse interface that can be used to operate a computer using the movement of the eyes is described. We developed this eye-tracking system for eye motion disability rehabilitation. When the user watches the screen of a computer, a charge-coupled device will catch images of the user's eye and transmit it to the computer. A program, based on a new cross-line tracking and stabilizing algorithm, will locate the center point of the pupil in the images. The calibration factors and energy factors are designed for coordinate mapping and blink functions. After the system transfers the coordinates of pupil center in the images to the display coordinate, it will determine the point at which the user gazed on the display, then transfer that location to the game subroutine program. We used this eye-tracking system as a joystick to play a game with an application program in a multimedia environment. The experimental results verify the feasibility and validity of this eye-game system and the rehabilitation effects for the user's visual movement.

  3. Real time eye tracking using Kalman extended spatio-temporal context learning

    Science.gov (United States)

    Munir, Farzeen; Minhas, Fayyaz ul Amir Asfar; Jalil, Abdul; Jeon, Moongu

    2017-06-01

    Real time eye tracking has numerous applications in human computer interaction such as a mouse cursor control in a computer system. It is useful for persons with muscular or motion impairments. However, tracking the movement of the eye is complicated by occlusion due to blinking, head movement, screen glare, rapid eye movements, etc. In this work, we present the algorithmic and construction details of a real time eye tracking system. Our proposed system is an extension of Spatio-Temporal context learning through Kalman Filtering. Spatio-Temporal Context Learning offers state of the art accuracy in general object tracking but its performance suffers due to object occlusion. Addition of the Kalman filter allows the proposed method to model the dynamics of the motion of the eye and provide robust eye tracking in cases of occlusion. We demonstrate the effectiveness of this tracking technique by controlling the computer cursor in real time by eye movements.

  4. Direct evidence for attention-dependent influences of the frontal eye-fields on feature-responsive visual cortex.

    Science.gov (United States)

    Heinen, Klaartje; Feredoes, Eva; Weiskopf, Nikolaus; Ruff, Christian C; Driver, Jon

    2014-11-01

    Voluntary selective attention can prioritize different features in a visual scene. The frontal eye-fields (FEF) are one potential source of such feature-specific top-down signals, but causal evidence for influences on visual cortex (as was shown for "spatial" attention) has remained elusive. Here, we show that transcranial magnetic stimulation (TMS) applied to right FEF increased the blood oxygen level-dependent (BOLD) signals in visual areas processing "target feature" but not in "distracter feature"-processing regions. TMS-induced BOLD signals increase in motion-responsive visual cortex (MT+) when motion was attended in a display with moving dots superimposed on face stimuli, but in face-responsive fusiform area (FFA) when faces were attended to. These TMS effects on BOLD signal in both regions were negatively related to performance (on the motion task), supporting the behavioral relevance of this pathway. Our findings provide new causal evidence for the human FEF in the control of nonspatial "feature"-based attention, mediated by dynamic influences on feature-specific visual cortex that vary with the currently attended property.

  5. Emotional modulation of the attentional blink: is there an effect of stress?

    Science.gov (United States)

    Schwabe, Lars; Wolf, Oliver T

    2010-04-01

    Individuals are often unable to identify the second target (T2) of two when it is presented within 500 ms after the first target (T1). This "attentional blink" (AB) is attenuated by an emotionally arousing T2. Stress is known to affect cognitive performance, in particular for emotional material. In the present study, we asked whether (a) an emotional T2 reduces the AB when preceded by an emotional T1 and (b) the emotional modulation of the AB is affected by stress. Participants were presented neutral and aversive words as T1 and T2 in rapid serial visual presentation after they were exposed to stress (socially evaluated cold pressor test) or a control condition in a crossover manner. Our results indicate that an aversive T1 extends the AB. Aversive T2 attenuated the AB in the presence of a neutral, but not an aversive, T1. Stress-enhanced T2 detection and high cortisol responses to stress reduced the AB. However, neither stress nor cortisol interacted with the emotionality of the target words. In summary, these findings point to a strong impact of emotional factors on early perceptual experiences.

  6. The Effects of Emotional Target and Mood State of Participants on Attentional Blink

    Directory of Open Access Journals (Sweden)

    Wai-Shan Chan

    2011-05-01

    Full Text Available Previous studies have found that attentional blink (AB, a failure to report targets temporally close to each other, can be attenuated separately by (1 emotionally significant test stimuli (T2 and (2 the emotional state of the observer. In the present study, we asked whether and how the (1 and (2 interact. Participants were induced with either positive or negative music and asked to complete an AB task which consisted of low-arousal positive, neutral and negative words as T2. We found low arousal negative words significantly reduced AB more than did other words, while no main nor interaction effect for mood was observed. However, on repeating the experiment and replacing low arousal words with high-arousal ones we not only were able to replicate the finding of an advantage of negative words over others, but detected an effect for the mood of the observer: participants who were induced to become happier using music performed better in detecting T2 across lags and word categories than did participants who became sadder. Our findings suggest an interaction of arousal level of emotional target with the induced mood of participants although the underlying mechanisms responsible for this effect need further investigation.

  7. Usefulness of blink reflex in hypothyroid patients with or without polyneuropathy: a case control study.

    Science.gov (United States)

    Pawar, Sachin; Udan, Vikas; Jain, Jyoti; Shende, Vinod; Singh, Ramji

    2014-01-01

    Central nervous system (CNS) dysfunction is an important consequence of thyroid deficiency. Cranial nerves are frequently affected in hypothyroid process. On routine nerve conduction studies, symptomatic peripheral and cranial neuropathy can be detected, however, diagnosing subclinical cranial neuropathy pose the major problem. Blink reflex (BR), has been shown to be an effective method for revealing subclinical involvement of cranial nerves in generalized neuropathies. The present study was undertaken to evaluate the efficacy of BR as a method for early diagnosis of subclinical cranial neuropathy in hypothyroid patients with or without overt peripheral polyneuropathy. A case control study was conducted on 150 subjects aged 18 years and above (100 controls, 50 cases). A routine nerve conduction study and BR evaluation was done in all the subjects. We found abnormal BR response in 50% of hypothyroid patients studied. In hypothyroid patient without polyneuropathy R1 latency was significantly prolonged (P < 0.05 Vs control). Ipsilateral and contralateral R2 latencies were significantly prolonged in hypothyroid cases with or without polyneuropathy on bilateral stimulation. Magnitude of prolongation was greater in with polyneuropathy group. In conclusion, study suggests that BR is a useful non-invasive method for the detection of clinically silent cranial nerve compromise in hypothyroid patients.

  8. Painful faces-induced attentional blink modulated by top-down and bottom-up mechanisms

    Directory of Open Access Journals (Sweden)

    Chun eZheng

    2015-06-01

    Full Text Available Pain-related stimuli can capture attention in an automatic (bottom-up or intentional (top-down fashion. Previous studies have examined attentional capture by pain-related information using spatial attention paradigms that involve mainly a bottom-up mechanism. In the current study, we investigated the pain information–induced attentional blink (AB using a rapid serial visual presentation (RSVP task, and compared the effects of task-irrelevant and task-relevant pain distractors. Relationships between accuracy of target identification and individual traits (i.e., empathy and catastrophizing thinking about pain were also examined. The results demonstrated that task-relevant painful faces had a significant pain information–induced AB effect, whereas task-irrelevant faces a near-significant trend of this effect, supporting the notion that pain-related stimuli can influence the temporal dynamics of attention. Furthermore, we found a significant negative correlation between response accuracy and pain catastrophizing score in task-relevant trials. These findings suggest that active scanning of environmental information related to pain produces greater deficits in cognition than does unintentional attention toward pain, which may represent the different ways in which healthy individuals and patients with chronic pain process pain-relevant information. These results may provide insight into the understanding of maladaptive attentional processing in patients with chronic pain.

  9. Painful faces-induced attentional blink modulated by top–down and bottom–up mechanisms

    Science.gov (United States)

    Zheng, Chun; Wang, Jin-Yan; Luo, Fei

    2015-01-01

    Pain-related stimuli can capture attention in an automatic (bottom–up) or intentional (top–down) fashion. Previous studies have examined attentional capture by pain-related information using spatial attention paradigms that involve mainly a bottom–up mechanism. In the current study, we investigated the pain information-induced attentional blink (AB) using a rapid serial visual presentation (RSVP) task, and compared the effects of task-irrelevant and task-relevant pain distractors. Relationships between accuracy of target identification and individual traits (i.e., empathy and catastrophizing thinking about pain) were also examined. The results demonstrated that task-relevant painful faces had a significant pain information-induced AB effect, whereas task-irrelevant faces showed a near-significant trend of this effect, supporting the notion that pain-related stimuli can influence the temporal dynamics of attention. Furthermore, we found a significant negative correlation between response accuracy and pain catastrophizing score in task-relevant trials. These findings suggest that active scanning of environmental information related to pain produces greater deficits in cognition than does unintentional attention toward pain, which may represent the different ways in which healthy individuals and patients with chronic pain process pain-relevant information. These results may provide insight into the understanding of maladaptive attentional processing in patients with chronic pain. PMID:26082731

  10. Painful faces-induced attentional blink modulated by top-down and bottom-up mechanisms.

    Science.gov (United States)

    Zheng, Chun; Wang, Jin-Yan; Luo, Fei

    2015-01-01

    Pain-related stimuli can capture attention in an automatic (bottom-up) or intentional (top-down) fashion. Previous studies have examined attentional capture by pain-related information using spatial attention paradigms that involve mainly a bottom-up mechanism. In the current study, we investigated the pain information-induced attentional blink (AB) using a rapid serial visual presentation (RSVP) task, and compared the effects of task-irrelevant and task-relevant pain distractors. Relationships between accuracy of target identification and individual traits (i.e., empathy and catastrophizing thinking about pain) were also examined. The results demonstrated that task-relevant painful faces had a significant pain information-induced AB effect, whereas task-irrelevant faces showed a near-significant trend of this effect, supporting the notion that pain-related stimuli can influence the temporal dynamics of attention. Furthermore, we found a significant negative correlation between response accuracy and pain catastrophizing score in task-relevant trials. These findings suggest that active scanning of environmental information related to pain produces greater deficits in cognition than does unintentional attention toward pain, which may represent the different ways in which healthy individuals and patients with chronic pain process pain-relevant information. These results may provide insight into the understanding of maladaptive attentional processing in patients with chronic pain.

  11. Eye Anatomy

    Science.gov (United States)

    ... News About Us Donate In This Section Eye Anatomy en Español email Send this article to a ... You at Risk For Glaucoma? Childhood Glaucoma Eye Anatomy Five Common Glaucoma Tests Glaucoma Facts and Stats ...

  12. Eye trauma

    African Journals Online (AJOL)

    2011-02-02

    Feb 2, 2011 ... will invariably lead to lid swelling, making the examination far more difficult. ... protect the eye with a pad or shield, give tetanus prophylaxis and refer. ... A study on penetrating eye injuries in South African children found.

  13. Blinking effect and the use of quantum dots in single molecule spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Rombach-Riegraf, Verena; Oswald, Peter; Bienert, Roland; Petersen, Jan [Albert-Ludwigs-Universitaet Freiburg, Institut fuer Physikalische Chemie, Albertstrasse 23a, 79104 Freiburg (Germany); Domingo, M.P. [Instituto de Carboquimica (CSIC), Miguel Luesma 4, 50018 Zaragoza (Spain); Pardo, Julian [Grupo Apoptosis, Inmunidad y Cancer, Departamento Bioquimica y Biologia Molecular y Celular, Fac. Ciencias, Universidad de Zaragoza, Zaragoza (Spain); Fundacion Aragon I-D (ARAID), Gobierno de Aragon, Zaragoza (Spain); Immune Effector Cells Group, Aragon Health Research Institute (IIS Aragon), Biomedical Research Centre of Aragon (CIBA) Fundacion Aragon I-D - ARAID, Gobierno de Aragon, Zaragoza (Spain); Graeber, P. [Albert-Ludwigs-Universitaet Freiburg, Institut fuer Physikalische Chemie, Albertstrasse 23a, 79104 Freiburg (Germany); Galvez, E.M., E-mail: eva@icb.csic.es [Instituto de Carboquimica (CSIC), Miguel Luesma 4, 50018 Zaragoza (Spain); Immune Effector Cells Group, Aragon Health Research Institute (IIS Aragon), Biomedical Research Centre of Aragon (CIBA) Fundacion Aragon I-D - ARAID, Gobierno de Aragon, Zaragoza (Spain)

    2013-01-04

    Highlights: Black-Right-Pointing-Pointer It is possible to eliminate the blinking effect of a water-soluble QD. Black-Right-Pointing-Pointer We provide a direct method to study protein function and dynamics at the single level. Black-Right-Pointing-Pointer QD, potent tool for single molecule studies of biochemical and biological processes. -- Abstract: Luminescent semiconductor nanocrystals (quantum dots, QD) have unique photo-physical properties: high photostability, brightness and narrow size-tunable fluorescence spectra. Due to their unique properties, QD-based single molecule studies have become increasingly more popular during the last years. However QDs show a strong blinking effect (random and intermittent light emission), which may limit their use in single molecule fluorescence studies. QD blinking has been widely studied and some hypotheses have been done to explain this effect. Here we summarise what is known about the blinking effect in QDs, how this phenomenon may affect single molecule studies and, on the other hand, how the 'on'/'off' states can be exploited in diverse experimental settings. In addition, we present results showing that site-directed binding of QD to cysteine residues of proteins reduces the blinking effect. This option opens a new possibility of using QDs to study protein-protein interactions and dynamics by single molecule fluorescence without modifying the chemical composition of the solution or the QD surface.

  14. Blink Number Forecasting Based on Improved Bayesian Fusion Algorithm for Fatigue Driving Detection

    Directory of Open Access Journals (Sweden)

    Wei Sun

    2015-01-01

    Full Text Available An improved Bayesian fusion algorithm (BFA is proposed for forecasting the blink number in a continuous video. It assumes that, at one prediction interval, the blink number is correlated with the blink numbers of only a few previous intervals. With this assumption, the weights of the component predictors in the improved BFA are calculated according to their prediction performance only from a few intervals rather than from all intervals. Therefore, compared with the conventional BFA, the improved BFA is more sensitive to the disturbed condition of the component predictors for adjusting their weights more rapidly. To determine the most relevant intervals, the grey relation entropy-based analysis (GREBA method is proposed, which can be used analyze the relevancy between the historical data flows of blink number and the data flow at the current interval. Three single predictors, that is, the autoregressive integrated moving average (ARIMA, radial basis function neural network (RBFNN, and Kalman filter (KF, are designed and incorporated linearly into the BFA. Experimental results demonstrate that the improved BFA obviously outperforms the conventional BFA in both accuracy and stability; also fatigue driving can be accurately warned against in advance based on the blink number forecasted by the improved BFA.

  15. Test-retest repeatability of the pupil light response to blue and red light stimuli in normal human eyes using a novel pupillometer

    DEFF Research Database (Denmark)

    Herbst, Kristina; Sander, Birgit; Milea, Dan

    2011-01-01

    In this study, we evaluated the repeatability of pupil responses to colored light stimuli in healthy subjects using a prototype chromatic pupillometer. One eye of 10 healthy subjects was tested twice in the same day using monochromatic light exposure at two selected wavelengths (660 and 470¿nm......, we have developed a novel prototype of color pupillometer which demonstrates good repeatability in evoking and recording the pupillary response to a bright blue and red light stimulus....

  16. Agility in consumer retail: Sense-Response Alignment through the eyes of customers

    Directory of Open Access Journals (Sweden)

    Maura Atapattu

    2014-06-01

    Full Text Available In hyper competition, firms that are agile: sensing and responding better to customer requirements tend to be more successful and achieve supernormal profits. In spite of the widely accepted importance of customer agility, research is limited on this construct. The limited research also has predominantly focussed on the firm’s perspective of agility. However, we propose that the customers are better positioned to determine how well a firm is responding to their requirements (aka a firm’s customer agility. Taking the customers’ stand point, we address the issue of sense and respond alignment in two perspectives-matching and mediating. Based on data collected from customers in a field study, we tested hypothesis pertaining to the two methods of alignment using polynomial regression and response surface methodology. The results provide a good explanation for the role of both forms of alignment on customer satisfaction. Implication for research and practice are discussed.

  17. Eye-specification genes in the bacterial light organ of the bobtail squid Euprymna scolopes, and their expression in response to symbiont cues

    Science.gov (United States)

    Peyer, Suzanne M.; Pankey, M. Sabrina; Oakley, Todd H.; McFall-Ngai, Margaret J.

    2014-01-01

    The squid Euprymna scolopes has evolved independent sets of tissues capable of light detection, including a complex eye and a photophore or ‘light organ’, which houses the luminous bacterial symbiont Vibrio fischeri. As the eye and light organ originate from different embryonic tissues, we examined whether the eye-specification genes, pax6, eya, six, and dac, are shared by these two organs, and if so, whether they are regulated in the light organ by symbiosis. We obtained sequences of the four genes with PCR, confirmed orthology with phylogenetic analysis, and determined that each was expressed in the eye and light organ. With in situ hybridization (ISH), we localized the gene transcripts in developing embryos, comparing the patterns of expression in the two organs. The four transcripts localized to similar tissues, including those associated with the visual system ~1/4 into embryogenesis (Naef stage 18) and the light organ ~3/4 into embryogenesis (Naef stage 26). We used ISH and quantitative real-time PCR to examine transcript expression and differential regulation in postembryonic light organs in response to the following colonization conditions: wild-type, luminescent V. fischeri; a mutant strain defective in light production; and as a control, no symbiont. In ISH experiments light organs showed down regulation of the pax6, eya, and six transcripts in response to wild-type V. fischeri. Mutant strains also induced down regulation of the pax6 and eya transcripts, but not of the six transcript. Thus, luminescence was required for down regulation of the six transcript. We discuss these results in the context of symbiont-induced light-organ development. Our study indicates that the eye-specification genes are expressed in light-interacting tissues independent of their embryonic origin and are capable of responding to bacterial cues. These results offer evidence for evolutionary tinkering or the recruitment of eye development genes for use in a light

  18. What Is Dry Eye?

    Medline Plus

    Full Text Available ... the right type of tears. How do tears work? When you blink, a film of tears spreads ... Financial Relationships with Industry Medical Disclaimer Privacy Policy Terms of Service For Advertisers For Media Ophthalmology Job ...

  19. 77 FR 30349 - Alderox, Inc., Applied Solar, Inc., Artes Medical, Inc., AskMeNow, Inc., Blink Logic Inc., and...

    Science.gov (United States)

    2012-05-22

    ... From the Federal Register Online via the Government Publishing Office SECURITIES AND EXCHANGE COMMISSION Alderox, Inc., Applied Solar, Inc., Artes Medical, Inc., AskMeNow, Inc., Blink Logic Inc., and... information concerning the securities of Blink Logic Inc. because it has not filed any periodic reports since...

  20. Priming the semantic neighbourhood during the attentional blink.

    Directory of Open Access Journals (Sweden)

    Irina M Harris

    Full Text Available BACKGROUND: When two targets are presented in close temporal proximity amongst a rapid serial visual stream of distractors, a period of disrupted attention and attenuated awareness lasting 200-500 ms follows identification of the first target (T1. This phenomenon is known as the "attentional blink" (AB and is generally attributed to a failure to consolidate information in visual short-term memory due to depleted or disrupted attentional resources. Previous research has shown that items presented during the AB that fail to reach conscious awareness are still processed to relatively high levels, including the level of meaning. For example, missed word stimuli have been shown to prime later targets that are closely associated words. Although these findings have been interpreted as evidence for semantic processing during the AB, closely associated words (e.g., day-night may also rely on specific, well-worn, lexical associative links which enhance attention to the relevant target. METHODOLOGY/PRINCIPAL FINDINGS: We used a measure of semantic distance to create prime-target pairs that are conceptually close, but have low word associations (e.g., wagon and van and investigated priming from a distractor stimulus presented during the AB to a subsequent target (T2. The stimuli were words (concrete nouns in Experiment 1 and the corresponding pictures of objects in Experiment 2. In both experiments, report of T2 was facilitated when this item was preceded by a semantically-related distractor. CONCLUSIONS/SIGNIFICANCE: This study is the first to show conclusively that conceptual information is extracted from distractor stimuli presented during a period of attenuated awareness and that this information spreads to neighbouring concepts within a semantic network.

  1. Revisiting the spread of sparing in the attentional blink.

    Science.gov (United States)

    Chen, Xi; Zhou, Xiaolin

    2015-07-01

    The attentional blink (AB) refers to a deficit in reporting the second of two targets (T2) in a rapid serial visual presentation (RSVP) stream when this target is presented less than 500 ms after the onset of the first target (T1). It is under debate whether the AB originates from a limitation of cognitive resources or from an attentional suppression process triggered by a distractor or by target discontinuity. In this study, we placed a distractor (D(inter)) or an extra target (T(inter)) between T1 and T2 while at the same time manipulating the time interval between D(inter) (or T(inter)) and T2 (0, 200, or 500 ms). The level of attentional enhancement induced by the detection of T1 was also manipulated by adding external noise to T1. The results showed that, as compared to the dual-target condition, T2 performance was better in the consecutive-target condition, when T2 was close in time to T(inter) (i.e., the spread of sparing), but was worse with a longer interval between T2 and the preceding item. Adding external noise to T1 improved T2 performance when T2 was close in time to the preceding item, irrespective of whether this item was D(inter) or T(inter). These findings present difficulties for the existing models of the AB, although the overall pattern observed is generally more consistent with the episodic simultaneous-type, serial-token (eSTST) model than with conventional resource accounts or distractor-based attentional selection accounts of the AB.

  2. Distractor inhibition predicts individual differences in the attentional blink.

    Directory of Open Access Journals (Sweden)

    Paul E Dux

    Full Text Available BACKGROUND: The attentional blink (AB refers to humans' impaired ability to detect the second of two targets (T2 in a rapid serial visual presentation (RSVP stream of distractors if it appears within 200-600 ms of the first target (T1. Here we examined whether humans' ability to inhibit distractors in the RSVP stream is a key determinant of individual differences in T1 performance and AB magnitude. METHODOLOGY/PRINCIPAL FINDINGS: We presented subjects with RSVP streams (93.3 ms/item of letters containing white distractors, a red T1 and a green T2. Subjects' ability to suppress distractors was assessed by determining the extent to which their second target performance was primed by a preceding distractor that shared the same identity as T2. Individual subjects' magnitude of T2 priming from this distractor was found to be negatively correlated with their T1 accuracy and positively related to their AB magnitude. In particular, subjects with attenuated ABs showed negative priming (i.e., worse T2 performance when the priming distractor appeared in the RSVP stream compared to when it was absent, whereas those with large ABs displayed positive priming (i.e., better T2 performance when the priming distractor appeared in the RSVP stream compared to when it was absent. Thus, a subject's ability to suppress distractors, as assessed by T2 priming magnitude, predicted both their T1 performance and AB magnitude. CONCLUSIONS/SIGNIFICANCE: These results confirm that distractor suppression plays a key role in RSVP target selection and support the hypothesis that the AB results, at least in part, from a failure of distractor inhibition.

  3. Musical minds: attentional blink reveals modality-specific restrictions.

    Directory of Open Access Journals (Sweden)

    Sander Martens

    Full Text Available Formal musical training is known to have positive effects on attentional and executive functioning, processing speed, and working memory. Consequently, one may expect to find differences in the dynamics of temporal attention between musicians and non-musicians. Here we address the question whether that is indeed the case, and whether any beneficial effects of musical training on temporal attention are modality specific or generalize across sensory modalities.When two targets are presented in close temporal succession, most people fail to report the second target, a phenomenon known as the attentional blink (AB. We measured and compared AB magnitude for musicians and non-musicians using auditory or visually presented letters and digits. Relative to non-musicians, the auditory AB was both attenuated and delayed in musicians, whereas the visual AB was larger. Non-musicians with a large auditory AB tended to show a large visual AB. However, neither a positive nor negative correlation was found in musicians, suggesting that at least in musicians, attentional restrictions within each modality are completely separate.AB magnitude within one modality can generalize to another modality, but this turns out not to be the case for every individual. Formal musical training seems to have a domain-general, but modality-specific beneficial effect on selective attention. The results fit with the idea that a major source of attentional restriction as reflected in the AB lies in modality-specific, independent sensory systems rather than a central amodal system. The findings demonstrate that individual differences in AB magnitude can provide important information about the modular structure of human cognition.

  4. Musical minds: attentional blink reveals modality-specific restrictions.

    Science.gov (United States)

    Martens, Sander; Wierda, Stefan M; Dun, Mathijs; de Vries, Michal; Smid, Henderikus G O M

    2015-01-01

    Formal musical training is known to have positive effects on attentional and executive functioning, processing speed, and working memory. Consequently, one may expect to find differences in the dynamics of temporal attention between musicians and non-musicians. Here we address the question whether that is indeed the case, and whether any beneficial effects of musical training on temporal attention are modality specific or generalize across sensory modalities. When two targets are presented in close temporal succession, most people fail to report the second target, a phenomenon known as the attentional blink (AB). We measured and compared AB magnitude for musicians and non-musicians using auditory or visually presented letters and digits. Relative to non-musicians, the auditory AB was both attenuated and delayed in musicians, whereas the visual AB was larger. Non-musicians with a large auditory AB tended to show a large visual AB. However, neither a positive nor negative correlation was found in musicians, suggesting that at least in musicians, attentional restrictions within each modality are completely separate. AB magnitude within one modality can generalize to another modality, but this turns out not to be the case for every individual. Formal musical training seems to have a domain-general, but modality-specific beneficial effect on selective attention. The results fit with the idea that a major source of attentional restriction as reflected in the AB lies in modality-specific, independent sensory systems rather than a central amodal system. The findings demonstrate that individual differences in AB magnitude can provide important information about the modular structure of human cognition.

  5. Suppressed blinking behavior of CdSe/CdS QDs by polymer coating

    Science.gov (United States)

    Zhang, Aidi; Bian, Yannan; Wang, Jinjie; Chen, Kuiyong; Dong, Chaoqing; Ren, Jicun

    2016-02-01

    Semiconductor quantum dots (QDs) are very important fluorescent nanocrystals with excellent optical properties. However, QDs, at the single-particle level, show severe fluorescence intermittency (or blinking) on a wide time scale from milliseconds to minutes, which limits certain optical and biological applications. Generally, blinking behavior of QDs strongly depends on their surface state and surrounding environment. Therefore, current blinking suppression approaches are mostly focused on the introduction of an inorganic shell and organic small molecule compounds. In this study, we described a ``bottom up'' approach for the synthesis of CdSe/CdS/polymer core/shell/shell QDs via the in situ one-pot polymerization approach in order to control the blinking behavior of QDs. Three monomers (dithiothreitol (DTT), phenylenediamine (PDA), and hexamethylenediamine (HDA)) were respectively used to polymerize with hexachlorocyclotriphosphazene (HCCP), and then the polyphosphazene polymers were obtained with cyclotriphosphazene as the basic macromolecular backbone. By regulating the molar ratios of the activated comonomers, we can control the blinking behavior of CdSe/CdS/polymer QDs. Under the optimal conditions, the percentage of ``non-blinking'' CdSe/CdS/polymer QDs (the ``on time'' fraction > 99% of the overall observation time) was up to 78%. The suppression mechanism was attributed to the efficient passivation of QD surface traps by the sulfhydryl or phenyl groups in the polyphosphazene polymers.Semiconductor quantum dots (QDs) are very important fluorescent nanocrystals with excellent optical properties. However, QDs, at the single-particle level, show severe fluorescence intermittency (or blinking) on a wide time scale from milliseconds to minutes, which limits certain optical and biological applications. Generally, blinking behavior of QDs strongly depends on their surface state and surrounding environment. Therefore, current blinking suppression approaches are

  6. New Methods of Detecting Voluntary Blinking Used to Communicate with Disabled People

    Directory of Open Access Journals (Sweden)

    BOZOMITU, R.-G.

    2012-11-01

    Full Text Available In this paper two new methods of detecting a voluntary blinking and neglecting involuntary blinks are comparatively presented. This technique is used to communicate with disabled people by using the EOG acquisition system. The proposed methods are based on Hilbert transform and envelope detection of the low frequency differential EOG signals. To safely detect voluntary blinking pulses, these methods use an adaptive threshold depending on the level of the low frequency EOG signal. The prototype of the proposed system has been designed, constructed and tested for different subjects from medical care centers, hospitals and treatment units. The experiments that we made with patients have confirmed the performing operation of the proposed EOG acquisition system.

  7. Eye Absence Does Not Regulate Planarian Stem Cells during Eye Regeneration.

    Science.gov (United States)

    LoCascio, Samuel A; Lapan, Sylvain W; Reddien, Peter W

    2017-02-27

    Dividing cells called neoblasts contain pluripotent stem cells and drive planarian flatworm regeneration from diverse injuries. A long-standing question is whether neoblasts directly sense and respond to the identity of missing tissues during regeneration. We used the eye to investigate this question. Surprisingly, eye removal was neither sufficient nor necessary for neoblasts to increase eye progenitor production. Neoblasts normally increase eye progenitor production following decapitation, facilitating regeneration. Eye removal alone, however, did not induce this response. Eye regeneration following eye-specific resection resulted from homeostatic rates of eye progenitor production and less cell death in the regenerating eye. Conversely, large head injuries that left eyes intact increased eye progenitor production. Large injuries also non-specifically increased progenitor production for multiple uninjured tissues. We propose a model for eye regeneration in which eye tissue production by planarian stem cells is not directly regulated by the absence of the eye itself. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Hurricane Sandy: Caught in the eye of the storm and a city's adaptation response

    Science.gov (United States)

    Orton, P. M.; Horton, R. M.; Blumberg, A. F.; Rosenzweig, C.; Solecki, W.; Bader, D.

    2015-12-01

    The NOAA RISA program has funded the seven-institution Consortium for Climate Risk in the Urban Northeast (CCRUN) for the past five years to serve stakeholder needs in assessing and managing risks from climate variability and change. When Hurricane Sandy struck, we were in an ideal position, making flood forecasts and communicating NOAA forecasts to the public with dozens of media placements, translating the poorly understood flood forecasts into human dimensions. In 2013 and 2015, by request of New York City (NYC), we worked through the NYC Panel on Climate Change to deliver updated climate risk assessment reports, to be used in the post-Sandy rebuilding and resiliency efforts. These utilized innovative methodologies for probabilistic local and regional sea level change projections, and contrasted methods of dynamic versus (the more common) static flood mapping. We participated in a federal-academic partnership that developed a Sea Level Tool for Sandy Recovery that integrates CCRUN sea level rise projections with policy-relevant FEMA flood maps, and now several updated flood maps and coastal flood mapping tools (NOAA, FEMA, and USACE) incorporate our projections. For the adaptation response, we helped develop NYC's $20 billion flood adaptation plan, and we were on a winning team under the Housing and Urban Development Rebuild By Design (RBD) competition, a few of the many opportunities that arose with negligible additional funding and which CCRUN funds supported. Our work at times disrupted standard lines of thinking, but NYC showed an openness to altering course. In one case we showed that an NYC plan of wetland restoration in Jamaica Bay would provide no reduction in flooding unless deep-dredged channels circumventing them were shallowed or narrowed. In another, the lead author's RBD team challenged the notion at one location that levees were the solution to accelerating sea level rise, developing a plan to use ecological breakwaters and layered components of

  9. Student attitudes regarding the educational value and welfare implications in the use of model eyes and live dogs in teaching practical fundus examination: evaluation of responses from 40 students

    Directory of Open Access Journals (Sweden)

    D.L. Williams

    2016-10-01

    Full Text Available This study sought to document student opinions on the educational value and welfare implications of use of artificial model eyes and live dogs in the training of veterinary students in examination of the canine fundus. Forty students who had undertaken a practical class on canine fundoscopy involving both use of artificial model eyes and live dogs were asked to complete a short questionnaire using a Likert scale to gauge their opinion on whether the use of live dogs and artificial eyes was very valuable (scoring 2, valuable (1, a neutral response (0, not particularly valuable (-1 or not at all valuable (-2 and to write a free text response on their views of the educational value and welfare implications of using artificial model eyes or live dogs in training for ophthalmic examination of the canine ocular fundus. Likert responses were 1.84±0.37 for using live greyhounds and 0.58±0.79 for using simulator eyes (p<0.0001. Thematic analysis of the written responses showed that while the artificial eyes were considered somewhat valuable in initial training, the live dogs were significantly preferred for their realism and the opportunity to examine the eye while handling a live animal. In conclusion, while model eyes are valuable initial training in use of the ophthalmoscope for funduscopic examination, students consider that examining the eye in the live dog is significantly more valuable and that the welfare of dogs thus used is not in their view unduly compromised.

  10. In the Blink of an Eye: Relating Positive-Feedback Sensitivity to Striatal Dopamine D2-Like Receptors through Blink Rate

    Science.gov (United States)

    Groman, Stephanie M.; James, Alex S.; Seu, Emanuele; Tran, Steven; Clark, Taylor A.; Harpster, Sandra N.; Crawford, Maverick; Burtner, Joanna Lee; Feiler, Karen; Roth, Robert H.; Elsworth, John D.; London, Edythe D.

    2014-01-01

    For >30 years, positron emission tomography (PET) has proven to be a powerful approach for measuring aspects of dopaminergic transmission in the living human brain; this technique has revealed important relationships between dopamine D2-like receptors and dimensions of normal behavior, such as human impulsivity, and psychopathology, particularly behavioral addictions. Nevertheless, PET is an indirect estimate that lacks cellular and functional resolution and, in some cases, is not entirely pharmacologically specific. To identify the relationships between PET estimates of D2-like receptor availability and direct in vitro measures of receptor number, affinity, and function, we conducted neuroimaging and behavioral and molecular pharmacological assessments in a group of adult male vervet monkeys. Data gathered from these studies indicate that variation in D2-like receptor PET measurements is related to reversal-learning performance and sensitivity to positive feedback and is associated with in vitro estimates of the density of functional dopamine D2-like receptors. Furthermore, we report that a simple behavioral measure, eyeblink rate, reveals novel and crucial links between neuroimaging assessments and in vitro measures of dopamine D2 receptors. PMID:25339755

  11. In the blink of an eye: relating positive-feedback sensitivity to striatal dopamine D2-like receptors through blink rate.

    Science.gov (United States)

    Groman, Stephanie M; James, Alex S; Seu, Emanuele; Tran, Steven; Clark, Taylor A; Harpster, Sandra N; Crawford, Maverick; Burtner, Joanna Lee; Feiler, Karen; Roth, Robert H; Elsworth, John D; London, Edythe D; Jentsch, James David

    2014-10-22

    For >30 years, positron emission tomography (PET) has proven to be a powerful approach for measuring aspects of dopaminergic transmission in the living human brain; this technique has revealed important relationships between dopamine D2-like receptors and dimensions of normal behavior, such as human impulsivity, and psychopathology, particularly behavioral addictions. Nevertheless, PET is an indirect estimate that lacks cellular and functional resolution and, in some cases, is not entirely pharmacologically specific. To identify the relationships between PET estimates of D2-like receptor availability and direct in vitro measures of receptor number, affinity, and function, we conducted neuroimaging and behavioral and molecular pharmacological assessments in a group of adult male vervet monkeys. Data gathered from these studies indicate that variation in D2-like receptor PET measurements is related to reversal-learning performance and sensitivity to positive feedback and is associated with in vitro estimates of the density of functional dopamine D2-like receptors. Furthermore, we report that a simple behavioral measure, eyeblink rate, reveals novel and crucial links between neuroimaging assessments and in vitro measures of dopamine D2 receptors.

  12. Preferential access to emotion under attentional blink: evidence for threshold phenomenon

    Directory of Open Access Journals (Sweden)

    Szczepanowski Remigiusz

    2015-03-01

    Full Text Available The present study provides evidence that the activation strength produced by emotional stimuli must pass a threshold level in order to be consciously perceived, contrary to the assumption of continuous quality of representation. An analysis of receiver operating characteristics (ROC for attentional blink performance was used to distinguish between two (continuous vs. threshold models of emotion perception by inspecting two different ROC’s shapes. Across all conditions, the results showed that performance in the attentional blink task was better described by the two-limbs ROC predicted by the Krantz threshold model than by the curvilinear ROC implied by the signal-detection theory.

  13. Observation and control of blinking nitrogen-vacancy centres in discrete nanodiamonds.

    Science.gov (United States)

    Bradac, C; Gaebel, T; Naidoo, N; Sellars, M J; Twamley, J; Brown, L J; Barnard, A S; Plakhotnik, T; Zvyagin, A V; Rabeau, J R

    2010-05-01

    Nitrogen-vacancy colour centres in diamond can undergo strong, spin-sensitive optical transitions under ambient conditions, which makes them attractive for applications in quantum optics, nanoscale magnetometry and biolabelling. Although nitrogen-vacancy centres have been observed in aggregated detonation nanodiamonds and milled nanodiamonds, they have not been observed in very small isolated nanodiamonds. Here, we report the first direct observation of nitrogen-vacancy centres in discrete 5-nm nanodiamonds at room temperature, including evidence for intermittency in the luminescence (blinking) from the nanodiamonds. We also show that it is possible to control this blinking by modifying the surface of the nanodiamonds.

  14. Combining EEG and eye tracking: Identification, characterization and correction of eye movement artifacts in electroencephalographic data

    Directory of Open Access Journals (Sweden)

    Michael ePlöchl

    2012-10-01

    Full Text Available Eye movements introduce large artifacts to electroencephalographic recordings (EEG and thus render data analysis difficult or even impossible. Trials contaminated by eye movement and blink artifacts have to be discarded, hence in standard EEG-paradigms subjects are required to fixate on the screen. To overcome this restriction, several correction methods including regression and blind source separation have been proposed. Yet, there is no automated standard procedure established. By simultaneously recording eye movements and 64-channel-EEG during a guided eye movement paradigm, we show that eye movement artifacts consist of several components, which arise from different sources. These include corneo-retinal dipole changes, saccadic spike potentials and eyelid movements. Moreover, we demonstrate that depending on electrode site, gaze direction and choice of reference these components contribute differently to the measured signal. Therefore they cannot be removed by regression-based correction methods, as these inevitably over- or under-correct individual artifact components. Finally we propose a correction procedure based on Independent Component Analysis (ICA. This procedure uses eye tracker information to reliably and objectively identify eye-artifact related ICA-components in an automated manner. We demonstrate that this approach allows removing or substantially reducing ocular artifacts including microsaccades without affecting the signal originating from brain sources. In conclusion the proposed method does not only provide a tool for detecting and correcting eye artifacts in standard EEG-paradigms but it also permits to study EEG-activity during eye tracking experiments and thus to investigate neural mechanisms of eye movement control and visual attention under natural conditions.

  15. Real-time eye motion compensation for OCT imaging with tracking SLO

    Science.gov (United States)

    Vienola, Kari V.; Braaf, Boy; Sheehy, Christy K.; Yang, Qiang; Tiruveedhula, Pavan; Arathorn, David W.; de Boer, Johannes F.; Roorda, Austin

    2012-01-01

    Fixational eye movements remain a major cause of artifacts in optical coherence tomography (OCT) images despite the increases in acquisition speeds. One approach to eliminate the eye motion is to stabilize the ophthalmic imaging system in real-time. This paper describes and quantifies the performance of a tracking OCT system, which combines a phase-stabilized optical frequency domain imaging (OFDI) system and an eye tracking scanning laser ophthalmoscope (TSLO). We show that active eye tracking minimizes artifacts caused by eye drift and micro saccades. The remaining tracking lock failures caused by blinks and large saccades generate a trigger signal which signals the OCT system to rescan corrupted B-scans. Residual motion artifacts in the OCT B-scans are reduced to 0.32 minutes of arc (~1.6 µm) in an in vivo human eye enabling acquisition of high quality images from the optic nerve head and lamina cribrosa pore structure. PMID:23162731

  16. Emotional modulation of attention: fear increases but disgust reduces the attentional blink.

    Directory of Open Access Journals (Sweden)

    Nicolas Vermeulen

    Full Text Available BACKGROUND: It is well known that facial expressions represent important social cues. In humans expressing facial emotion, fear may be configured to maximize sensory exposure (e.g., increases visual input whereas disgust can reduce sensory exposure (e.g., decreases visual input. To investigate whether such effects also extend to the attentional system, we used the "attentional blink" (AB paradigm. Many studies have documented that the second target (T2 of a pair is typically missed when presented within a time window of about 200-500 ms from the first to-be-detected target (T1; i.e., the AB effect. It has recently been proposed that the AB effect depends on the efficiency of a gating system which facilitates the entrance of relevant input into working memory, while inhibiting irrelevant input. Following the inhibitory response on post T1 distractors, prolonged inhibition of the subsequent T2 is observed. In the present study, we hypothesized that processing facial expressions of emotion would influence this attentional gating. Fearful faces would increase but disgust faces would decrease inhibition of the second target. METHODOLOGY/PRINCIPAL FINDINGS: We showed that processing fearful versus disgust faces has different effects on these attentional processes. We found that processing fear faces impaired the detection of T2 to a greater extent than did the processing disgust faces. This finding implies emotion-specific modulation of attention. CONCLUSIONS/SIGNIFICANCE: Based on the recent literature on attention, our finding suggests that processing fear-related stimuli exerts greater inhibitory responses on distractors relative to processing disgust-related stimuli. This finding is of particular interest for researchers examining the influence of emotional processing on attention and memory in both clinical and normal populations. For example, future research could extend upon the current study to examine whether inhibitory processes invoked by

  17. Diabetes eye exams

    Science.gov (United States)

    Diabetic retinopathy - eye exams; Diabetes - eye exams; Glaucoma - diabetic eye exam; Macular edema - diabetic eye exam ... if the doctor who takes care of your diabetes checks your eyes, you need an eye exam ...

  18. What Is Dry Eye?

    Medline Plus

    Full Text Available ... Causes of Dry Eye Dry Eye Treatment What Is Dry Eye? Written By: Kierstan Boyd Reviewed By: ... your eyes do not produce enough tears, it is called dry eye. Dry eye is also when ...

  19. Facts About Pink Eye

    Science.gov (United States)

    ... Information > Pink Eye (Conjunctivitis) > Facts About Pink Eye Facts About Pink Eye Pink eye is one of ... for preventing eye infections. Last Reviewed: November 2015 Fact Sheet Blurb The National Eye Institute (NEI) is ...

  20. Dilating Eye Drops

    Science.gov (United States)

    ... Corneal Abrasions Dilating Eye Drops Lazy eye (defined) Pink eye (defined) Retinopathy of Prematurity Strabismus Stye (defined) Vision ... Corneal Abrasions Dilating Eye Drops Lazy eye (defined) Pink eye (defined) Retinopathy of Prematurity Strabismus Stye (defined) Vision ...

  1. Blinking effect and the use of quantum dots in single molecule spectroscopy.

    Science.gov (United States)

    Rombach-Riegraf, Verena; Oswald, Peter; Bienert, Roland; Petersen, Jan; Domingo, M P; Pardo, Julian; Gräber, P; Galvez, E M

    2013-01-01

    Luminescent semiconductor nanocrystals (quantum dots, QD) have unique photo-physical properties: high photostability, brightness and narrow size-tunable fluorescence spectra. Due to their unique properties, QD-based single molecule studies have become increasingly more popular during the last years. However QDs show a strong blinking effect (random and intermittent light emission), which may limit their use in single molecule fluorescence studies. QD blinking has been widely studied and some hypotheses have been done to explain this effect. Here we summarise what is known about the blinking effect in QDs, how this phenomenon may affect single molecule studies and, on the other hand, how the "on"/"off" states can be exploited in diverse experimental settings. In addition, we present results showing that site-directed binding of QD to cysteine residues of proteins reduces the blinking effect. This option opens a new possibility of using QDs to study protein-protein interactions and dynamics by single molecule fluorescence without modifying the chemical composition of the solution or the QD surface.

  2. Individual Differences in the Attentional Blink : The Temporal Profile of Blinkers and Non-Blinkers

    NARCIS (Netherlands)

    Willems, Charlotte; Wierda, Stefan M.; van Viegen, Eva; Martens, Sander

    2013-01-01

    Background: When two targets are presented in close temporal succession, the majority of people frequently fail to report the second target. This phenomenon, known as the 'attentional blink' (AB), has been a major topic in attention research for the past twenty years because it is informative about

  3. The temporal locus of the interaction between working memory consolidation and the attentional blink

    NARCIS (Netherlands)

    Akyürek, E.G.; Leszczyński, Marcin; Schubö, Anna

    2010-01-01

    An increase in concurrent working memory load has been shown to amplify the attentional blink. The present study investigated the temporal locus of this phenomenon, by using a dual rapid serial visual presentation paradigm that enabled the measurement of lateralized event-related potentials. The P3

  4. Testing models of the attentional blink : Does masking increase processing duration in RSVP?

    NARCIS (Netherlands)

    Wyble, Brad; Sense, Florian; Nieuwenstein, Mark

    2012-01-01

    Theories of the attentional blink (AB) – an impairment in perceiving the second of two targets shown within less than 500 ms of each other – generally assume that this effect reflects the time required to consolidate the first target in memory. In this view, the fact that the AB is strongly increase

  5. Control over experience? Magnitude of the attentional blink depends on meditative state

    NARCIS (Netherlands)

    Van Vugt, Marieke K.; Slagter, Heleen A.

    2014-01-01

    The information processing capacity of the human mind is limited, as is evidenced by the so-called 'attentional-blink' deficit. This deficit is believed to result from competition between stimuli for limited attentional resources. We examined to what extent advanced meditators can manipulate their a

  6. Under which conditions does T1 difficulty affect T2 performance in the attentional blink?

    DEFF Research Database (Denmark)

    Nielsen, Simon; Petersen, Anders; Andersen, Tobias Søren

    When two visual targets (T1 & T2) are presented in rapid succession, performance of T2 suffers up to 900 ms. One theory of this attentional blink (Raymond, Shapiro, & Arnell, 1992) propose that T1 and T2 compete for limited processing resources (Chun & Potter, 1995), and predict that prolonging...

  7. Priming T2 in a Visual and Auditory Attentional Blink Task

    NARCIS (Netherlands)

    Burg, E. van der; Olivers, C.N.L.; Bronkhorst, A.W.; Theeuwes, J.

    2008-01-01

    Participants performed an attentional blink (AB) task including digits as targets and letters as distractors within the visual and auditory domains. Prior to the rapid serial visual presentation, a visual or auditory prime was presented in the form of a digit that was identical to the second target

  8. Computer and Modernization%Concurrency Control Algorithms with Balanced Blink-tree Database Index

    Institute of Scientific and Technical Information of China (English)

    包斌; 李亚岗

    2016-01-01

    针对B链树作为多版本数据库索引的并发控制机制,提出一种新的B链树结构修改并发控制算法。该算法将B链树结构修改操作划分为几个更小的原子修改操作,这些修改操作可以并发运行并且不会死锁。实验表明,新算法提高了并发度与事务的吞吐量,并保持B链树结构的一致性和平衡性。%Concerning the concurrency control mechanism for multiversion database index based on Blink-tree, a new Blink-tree concurrency control modification algorithm was proposed. The algorithm divides Blink-tree structure modification into several smal-ler atomic modifications which run concurrently and deadlock-free. The experimental results show that the new algorithm improves concurrency and transaction throughput, and retains consistency and balance of Blink-tree structure.

  9. Time to see the bigger picture : Individual differences in the attentional blink

    NARCIS (Netherlands)

    Willems, Charlotte; Martens, Sander

    2016-01-01

    If two to-be-identified targets are presented in close temporal succession, identification for the second target is typically impaired. This attentional blink (AB) phenomenon has long been considered as a robust, universal cognitive limitation. However, more recent studies have demonstrated that AB

  10. Under which conditions does T1 difficulty affect T2 performance in the attentional blink?

    DEFF Research Database (Denmark)

    Nielsen, Simon; Petersen, Anders; Andersen, Tobias Søren

    ) found that increasing the contrast of T1 decreased the attentional blink but Chua (2005) found the opposite effect. In the current study, we varied the perceptual difficulty of T1 in the two-target paradigm (Duncan, Ward, & Shapiro, 1994) both by changing the contrast and by changing the exposure...

  11. Is the Nociceptive Blink Reflex Associated with Psychological Factors in Healthy Participants?

    DEFF Research Database (Denmark)

    Costa, Yuri; Baad-Hansen, Lene; Bonjardim, Leonardo Rigoldi;

    2016-01-01

    AIMS: To evaluate the possible association between the nociceptive blink reflex (nBR) and various pain-related psychological measures: the Anxiety Sensitivity Index-3 (ASI-3), the Fear of Pain Questionnaire III (FPQ-III), the Pain Vigilance and Awareness Questionnaire (PVAQ), the Somatosensory...

  12. Resting EEG in Alpha and Beta Bands Predicts Individual Differences in Attentional Blink Magnitude

    Science.gov (United States)

    MacLean, Mary H.; Arnell, Karen M.; Cote, Kimberly A.

    2012-01-01

    Accuracy for a second target (T2) is reduced when it is presented within 500 ms of a first target (T1) in a rapid serial visual presentation (RSVP)--an attentional blink (AB). There are reliable individual differences in the magnitude of the AB. Recent evidence has shown that the attentional approach that an individual typically adopts during a…

  13. Distractor inhibition predicts individual differences in recovery from the attentional blink

    NARCIS (Netherlands)

    Slagter, H.A.; Georgopoulou, K.

    2013-01-01

    Background: The attentional blink (AB) refers to an impairment in detecting the second of two target stimuli presented in close succession in a rapid stream of distractors. Recent studies indicate that the AB results, in part, from distractor suppression mechanisms, that may be mediated by striatal

  14. Negative attentional set in the attentional blink : control is not lost

    NARCIS (Netherlands)

    Zhang, Dexuan; Zhou, Xiaolin; Martens, Sander

    2011-01-01

    The attentional blink (AB) refers to the finding that performance on the second of two targets (T1 and T2) in a rapidly presented stimulus stream is impaired when the targets are presented within 200-500 ms. This study investigates whether a negative attentional set, a form of top-down control, has

  15. Word Frequency and the Attentional Blink : The Effects of Target Difficulty on Retrieval and Consolidation Processes

    NARCIS (Netherlands)

    Wierda, Stefan M.; Taatgen, Niels A.; van Rijn, Hedderik; Martens, Sander

    2013-01-01

    Background: When a second target (T2) is presented in close succession of a first target (T1) within a stream of non-targets, people often fail to detect T2-a deficit known as the attentional blink (AB). Two types of theories can be distinguished that have tried to account for this phenomenon. Where

  16. Individual Differences in the Attentional Blink : The Temporal Profile of Blinkers and Non-Blinkers

    NARCIS (Netherlands)

    Willems, Charlotte; Wierda, Stefan M.; van Viegen, Eva; Martens, Sander

    2013-01-01

    Background: When two targets are presented in close temporal succession, the majority of people frequently fail to report the second target. This phenomenon, known as the 'attentional blink' (AB), has been a major topic in attention research for the past twenty years because it is informative about

  17. Photoluminescence blinking and carrier dynamics in giant nanocrystals with different electron confinement

    Science.gov (United States)

    Sampat, Sid; Guo, Yijun; Vela, Javier; Malko, Anton

    2012-02-01

    Quantum dots have shown great promise as high quantum yield photon sources for applications in bioimaging, LEDs, lasers, etc. However, their photoluminescence (PL) intermittency (blinking) often complicates practical implementations. Recently, a new breed of giant nanocrystal quantum dots (gNQDs) with a large number of shell monolayers (ML) has been developed that show strongly suppressed blinkingootnotetextY. Chen et al., JACS 130, 5026 (2008) and existence of multiexcitons.ootnotetextY.S. Park et al., Phys. Rev. Lett. 106, 187401 (2011)^,ootnotetextA. V. Malko et al., Nano Lett., accepted (2011) So far, their PL emission has been limited to around 630nm. In this work, we broadened this approach and extended gNQD emission to shorter wavelength in the visible spectrum. We investigated photostable CdSe/CdS gNQDs with small (480nm emission) core and compared them to large (625nm emission) core non-blinking gNQDs with similar shell thickness (14-17 ML). The small core dots show increased blinking behavior and shorter PL decay times in comparison to large core dots. The observed difference in blinking behavior is suggestive of different carrier confinement regimes leading to enhanced electron trapping at the dot's surface as well as modifications to non-radiative Auger recombination rates.

  18. Short-term memory and the attentional blink : Capacity versus content

    NARCIS (Netherlands)

    Akyürek, Elkan G; Hommel, Bernhard

    When people monitor the rapid serial visual presentation (RSVP) of stimuli for two targets (T1 and T2), they often miss T2 if it falls into a time window of about half a second after T1 onset, a phenomenon known as the attentional blink (AB). We found that overall performance in an RSVP task was

  19. Working memory capacity, intelligence, and the magnitude of the attentional blink revisited

    NARCIS (Netherlands)

    Martens, Sander; Johnson, Addie

    The attentional blink (AB) is a well-established phenomenon in the study of attention. This deficit in reporting the second of two targets presented in rapid serial visual presentation when it occurs 200-500 ms after the first is considered to reflect a fundamental limitation in attentional

  20. Attentional and Perceptual Factors Affecting the Attentional Blink for Faces and Objects

    Science.gov (United States)

    Landau, Ayelet N.; Bentin, Shlomo

    2008-01-01

    When 2 different visual targets presented among different distracters in a rapid serial visual presentation (RSVP) are separated by 400 ms or less, detection and identification of the 2nd targets are reduced relative to longer time intervals. This phenomenon, termed the "attentional blink" (AB), is attributed to the temporary engagement…

  1. Working memory capacity, intelligence, and the magnitude of the attentional blink revisited

    NARCIS (Netherlands)

    Martens, Sander; Johnson, Addie

    2009-01-01

    The attentional blink (AB) is a well-established phenomenon in the study of attention. This deficit in reporting the second of two targets presented in rapid serial visual presentation when it occurs 200-500 ms after the first is considered to reflect a fundamental limitation in attentional processi

  2. Delayed exciton emission and its relation to blinking in CdSe quantum dots

    NARCIS (Netherlands)

    Rabouw, F.T.; Kamp, M.; van Dijk-Moes, R.J.A.; Gamelin, D.R.; Koenderink, A.F.; Meijerink, A.; Vanmaekelbergh, D.

    2015-01-01

    The efficiency and stability of emission from semiconductor nanocrystal quantum dots (QDs) is negatively affected by "blinking" on the single-nanocrystal level, that is, random alternation of bright and dark periods. The time scales of these fluctuations can be as long as many seconds, orders of mag

  3. Distractor Devaluation Effect in the Attentional Blink: Direct Evidence for Distractor Inhibition

    Science.gov (United States)

    Kihara, Ken; Yagi, Yoshihiko; Takeda, Yuji; Kawahara, Jun I.

    2011-01-01

    When two targets (T1 and T2) are embedded in rapid serial visual presentation (RSVP), T2 is often missed (attentional blink, AB) if T2 follows T1 by less than 500 ms. Some have proposed that inhibition of a distractor following T1 contributes to the AB, but no direct evidence supports this proposal. This study examined distractor inhibition by…

  4. Resolving Single-Molecule Assembled Patterns with Superresolution Blink-Microscopy

    NARCIS (Netherlands)

    Cordes, Thorben; Strackharn, Mathias; Stahl, Stefan W.; Summerer, Wolfram; Steinhauer, Christian; Forthmann, Carsten; Puchner, Elias M.; Vogelsang, Jan; Gaub, Hermann E.; Tinnefeld, Philip

    2010-01-01

    In this paper we experimentally combine a recently developed AFM-based molecule-by-molecule assembly (single-molecule cut-and-paste, SMCP) with subdiffraction resolution fluorescence imaging. Using “Blink-Microscopy”, which exploits the fluctuating emission of single molecules for the reconstruction

  5. Your Eyes

    Science.gov (United States)

    ... eyes to see millions of colors. Helping You See It All Rods and cones process the light to give you the total picture. You're ... get cloudy, causing a cataract . A cataract prevents light from reaching the retina and makes it difficult to see. The eyes you have will be yours forever — ...

  6. Eyes - bulging

    Science.gov (United States)

    ... emotional support is important. When to Contact a Medical Professional Call your health care provider if: You have bulging eyes and the cause has not yet been diagnosed. Bulging eyes are accompanied by other symptoms. ... The provider will ask about your medical history and do a physical exam. Some questions ...

  7. Modern sports eye injuries.

    Science.gov (United States)

    Capão Filipe, J A; Rocha-Sousa, A; Falcão-Reis, F; Castro-Correia, J

    2003-11-01

    To determine the severity and long term sequelae of eye injuries caused by modern sports that could be responsible for significant ocular trauma in the future. Prospective observational study of 24 (25 eyes) athletes with sports related ocular injuries from health clubs, war games, adventure, radical and new types of soccer, presenting to an eye emergency department between 1992 and 2002 (10 years). Modern sports were responsible for 8.3% of the 288 total sports eye injuries reported. Squash (29.2%) was the most common cause, followed by paintball (20.8%) and motocross (16.6%). The most common diagnosis during the follow up period was retinal breaks (20%). 18 (75%) patients sustained a severe injury. The final visual acuity remained <20/100 in two paintball players. Ocular injuries resulting from modern sports are often severe. Adequate instruction of the participants in the games, proper use of eye protectors, and a routine complete ophthalmological examination after an eye trauma should be mandatory.

  8. Psychophysiological responsivity to script-driven imagery : an exploratory study of the effects of eye movements on public speaking flashforwards

    NARCIS (Netherlands)

    Kearns, M.; Engelhard, I.M.

    2015-01-01

    A principle characteristic of public speaking anxiety relates to intrusive mental images of potential future disasters. Previous research has found that the self-reported emotionality of such “flashforwards” can be reduced by a cognitively demanding, dual-task (e.g., making eye movements) performed

  9. Inhibition of Return in Response to Eye Gaze and Peripheral Cues in Young People with Asperger's Syndrome

    Science.gov (United States)

    Marotta, Andrea; Pasini, Augusto; Ruggiero, Sabrina; Maccari, Lisa; Rosa, Caterina; Lupianez, Juan; Casagrande, Maria

    2013-01-01

    Inhibition of return (IOR) reflects slower reaction times to stimuli presented in previously attended locations. In this study, we examined this inhibitory after-effect using two different cue types, eye-gaze and standard peripheral cues, in individuals with Asperger's syndrome and typically developing individuals. Typically developing…

  10. Response of the pearly eye melon fly Bactrocera cucurbitae(Coquillett)(Diptera:Tephritidae) mutant to host-associated visual cues

    Science.gov (United States)

    We report on a pearly eye mutant (PEM) line generated from a single male Bactrocera cucurbitae collected in Kapoho, Hawaii. Crossing experiments with colony wild-type flies indicate that the locus controlling this trait is autosomal and the mutant allele is recessive. Experiments with females to ass...

  11. Psychophysiological responsivity to script-driven imagery : an exploratory study of the effects of eye movements on public speaking flashforwards

    NARCIS (Netherlands)

    Kearns, M.; Engelhard, I.M.

    2015-01-01

    A principle characteristic of public speaking anxiety relates to intrusive mental images of potential future disasters. Previous research has found that the self-reported emotionality of such “flashforwards” can be reduced by a cognitively demanding, dual-task (e.g., making eye movements) performed

  12. Inhibition of Return in Response to Eye Gaze and Peripheral Cues in Young People with Asperger's Syndrome

    Science.gov (United States)

    Marotta, Andrea; Pasini, Augusto; Ruggiero, Sabrina; Maccari, Lisa; Rosa, Caterina; Lupianez, Juan; Casagrande, Maria

    2013-01-01

    Inhibition of return (IOR) reflects slower reaction times to stimuli presented in previously attended locations. In this study, we examined this inhibitory after-effect using two different cue types, eye-gaze and standard peripheral cues, in individuals with Asperger's syndrome and typically developing individuals. Typically developing…

  13. Prevalence and phenomenology of eye tics in Gilles de la Tourette syndrome.

    Science.gov (United States)

    Martino, Davide; Cavanna, Andrea E; Robertson, Mary M; Orth, Michael

    2012-10-01

    Eye tics seem to be common in Gilles de la Tourette syndrome (GTS). We analyzed the frequency and clinical characteristics of eye tics in 212 GTS patients. Of the 212 patients, 201 (94.8 %) reported eye tics in their life-time; 166 (78.3 %) reported eye movement tics (rolling eyes up/down, eyes looking sideways, staring), and 194 (91.5 %) eyelid/eyebrow movement tics (frowning, raising eyebrows, blinking or winking). Patients with eye movement tics were younger at age of GTS onset (7.1 ± 4 years) than those without (8.9 ± 6.8; p = 0.024). Tic severity positively correlated to lifetime history of eye and/or eyelid/eyebrow movement tics. Our data confirm that eye and eyelid/eyebrow movement tics are very common in GTS, and most patients have several types of eye tics over time. Eye tic phenomenology was similar in patients with or without co-morbidity. Eye tics are therefore likely to be a core feature of GTS and should be routinely evaluated in order to strengthen the clinician's confidence in diagnosing GTS.

  14. Effects of d-Amphetamine and Haloperidol on Modulation of the Human Acoustic Startle Response

    Directory of Open Access Journals (Sweden)

    Hossein Kaviani

    2006-04-01

    Full Text Available "nObjective:This study aimed to examine the effects of haloperidol and amphetamine on human startle response modulated by emotionally-toned film clips. "n "n Method:Sixty participants, in two groups (one receiving haloperidol and the other receiving amphetamine were tested using electromyography (EMG to measure eye-blink muscle (orbicular oculi while different emotions were induced by six 2-minute film clips. Results:An affective rating shows the negative and positive effects of the two drugs on emotional reactivity, neither amphetamine nor haloperidol had any impact on the modulation of the startle response. Conclusion: The methodological and theoretical aspects of the study and findings will be discussed.

  15. Intranasal oxytocin attenuates the human acoustic startle response independent of emotional modulation.

    Science.gov (United States)

    Ellenbogen, Mark A; Linnen, Anne-Marie; Cardoso, Christopher; Joober, Ridha

    2014-11-01

    Oxytocin promotes social affiliation in humans. However, the mechanisms underlying this phenomenon require further elucidation. The present study investigated the influence of intranasal oxytocin on basic emotional processing in men and women, using an emotion-modulated startle response paradigm. Eighty-four participants self-administered 24 IU of intranasal oxytocin or saline and completed an assessment of the acoustic startle reflex, using electromyography (EMG), with varying emotional foregrounds. Oxytocin had no impact on the affective modulation of the startle eye blink response, but significantly diminished the acoustic startle reflex irrespective of the emotional foreground. The results suggest that oxytocin facilitates prosocial behavior, in part, by attenuating basic physiological arousal. The dampening effect of oxytocin on EMG startle could possibly be used as an inexpensive marker of oxytocin's effect on limbic brain circuits.

  16. 临床综合分析及治疗儿童多瞬症%Clinical comprehensive analysis and treatment of children abnormal blinking

    Institute of Scientific and Technical Information of China (English)

    宿可昕; 王兴民; 马娟; 姜红; 魏秀华; 徐晶

    2015-01-01

    Objective To study the curative effect of integrated Chinese and Western medicines treatment by clinical practical observation, visual function training, drug therapy and psychological guidance in the treatment of children abnormal blinking.Methods Treatment was given according to pathogenesis of 168 children abnormal blinking cases by detailed inquiry, visual function examination and eye examination. Visual function training, drug therapy and psychological guidance were given as integrated Chinese and Western treatment.Results After receiving treatment, there were 126 cured cases in 1 course, accounting for 75.0% and 41 cured cases in 2 courses, accounting for 24.4%, while only 1 case with relieved symptoms (psychological factors).Conclusion Therapies of integrated Chinese and Western medicines can effectively treat children abnormal blinking by visual function training, lysine alkamine vitamin B12, Stulln, Gegenshumu decoction, and psychological guidance.%目的:探讨通过临床实践观察、视功能训练、药物及心理辅导等中西医结合方法治疗儿童多瞬症的疗效。方法通过详尽问诊、视功能检查及眼部检查了解明确168例儿童多瞬症发生的病因,按因施治,然后通过视功能训练、药物及心理辅导等中西医结合方法治疗儿童多瞬症。结果经治疗,1个疗程治愈者126例,占总人数的75.0%;2个疗程治愈者41例,占总人数的24.4%,只有1例患儿(心理因素)症状缓解。结论视功能训练、赖氨基醇维生素B12、施图伦、葛根舒目汤、心理辅导等中西医方法相结合可有效的治疗儿童多瞬症。

  17. What Is Dry Eye?

    Medline Plus

    Full Text Available ... Español Eye Health / Eye Health A-Z Dry Eye Sections What Is Dry Eye? Dry Eye Symptoms ... Dry Eye Dry Eye Treatment What Is Dry Eye? Written By: Kierstan Boyd Reviewed By: Brenda Pagan- ...

  18. What Is Dry Eye?

    Medline Plus

    Full Text Available ... Español Eye Health / Eye Health A-Z Dry Eye Sections What Is Dry Eye? Dry Eye Symptoms ... Dry Eye Dry Eye Treatment What Is Dry Eye? Leer en Español: ¿Qué Es el Ojo Seco? ...

  19. EEG and Eye Tracking Demonstrate Vigilance Enhancement with Challenge Integration

    Science.gov (United States)

    Bodala, Indu P.; Li, Junhua; Thakor, Nitish V.; Al-Nashash, Hasan

    2016-01-01

    Maintaining vigilance is possibly the first requirement for surveillance tasks where personnel are faced with monotonous yet intensive monitoring tasks. Decrement in vigilance in such situations could result in dangerous consequences such as accidents, loss of life and system failure. In this paper, we investigate the possibility to enhance vigilance or sustained attention using “challenge integration,” a strategy that integrates a primary task with challenging stimuli. A primary surveillance task (identifying an intruder in a simulated factory environment) and a challenge stimulus (periods of rain obscuring the surveillance scene) were employed to test the changes in vigilance levels. The effect of integrating challenging events (resulting from artificially simulated rain) into the task were compared to the initial monotonous phase. EEG and eye tracking data is collected and analyzed for n = 12 subjects. Frontal midline theta power and frontal theta to parietal alpha power ratio which are used as measures of engagement and attention allocation show an increase due to challenge integration (p EEG also shows statistically significant suppression on the frontoparietal and occipital cortices due to challenge integration (p EEG, we infer that saccade amplitude and saccade velocity decrease with vigilance decrement along with frontal midline theta and frontal theta to parietal alpha ratio. Conversely, blink rate and relative delta power increase with vigilance decrement. However, these measures exhibit a reverse trend when challenge stimulus appears in the task suggesting vigilance enhancement. Moreover, the mean reaction time is lower for the challenge integrated phase (RTmean = 3.65 ± 1.4s) compared to initial monotonous phase without challenge (RTmean = 4.6 ± 2.7s). Our work shows that vigilance level, as assessed by response of these vital signs, is enhanced by challenge integration. PMID:27375464

  20. Psychophysiological consideration of the blink reflex as a function of wavelength; Psychophysiologische Betrachtung des Lidschlussreflexes als Funktion der Wellenlaenge

    Energy Technology Data Exchange (ETDEWEB)

    Reidenbach, H.D. [Fachhochschule Koeln (Germany). Forschungsbereich Medizintechnik: Hochfrequenz- und Lasertechnik

    2004-07-01

    It has been shown in investigations of the blink reflex that the incidence depends on the wavelength of the applied laser radiation. The experimentally acquired correlation shows a remarkably weaker association to the V({lambda})-curve compared to the spectral visibility function. The present results might be described by a dependence which is known from the fundamental Weber-Fechner-law in psychophysics and might be given as a blink reflex function according to the Stevens power function. (orig.)

  1. What Is Dry Eye?

    Medline Plus

    Full Text Available ... Eye Symptoms Causes of Dry Eye Dry Eye Treatment What Is Dry Eye? Written By: Kierstan Boyd ... your vision. Privacy Policy Related New Dry Eye Treatment is a Tear-Jerker Jul 21, 2017 Three ...

  2. Diabetic Eye Disease

    Science.gov (United States)

    ... Other Dental Problems Diabetes & Sexual & Urologic Problems Diabetic Eye Disease What is diabetic eye disease? Diabetic eye disease is a group of ... loss can occur. How does diabetes affect my eyes? Diabetes affects your eyes when your blood glucose, ...

  3. Spontaneous Blinking Kinetics on Paralytic Lagophthalmos After Lid Load with Gold Weight or Autogenous Temporalis Fascia Sling.

    Science.gov (United States)

    Wambier, Sarah P F; Garcia, Denny M; Cruz, Antonio A V; Messias, Andre

    2016-04-01

    To assess the upper eyelid kinematics during spontaneous blinking in unilateral paralytic lagophthalmos before and after upper eyelid load with gold weight (GW) or autogenous temporalis fascia (TF) sling. Comparative case series. Patients with long-standing unresolved unilateral facial palsy who underwent surgical treatment with GW (n = 8) or upper lid cerclage with TF (n = 10). The contralateral eyelid served as the control for each patient (control group). Preoperative and postoperative measurements of spontaneous blink kinematics with magnetic search coil and clinical assessment of lid margin position, lagophthalmos and ocular surface exposure, and determine amplitude, maximum velocity and main sequence of spontaneous blinks; relative amplitude of blinks to the pupil center; ocular surface exposure scores; magnitude of lagophthalmos and mid-pupil lid distances. The mean (±SE) down-phase amplitude ratio between paralyzed and contralateral eyelids (blink gain) was 10.0% preoperatively for both groups and significantly increased to 29 ± 6% for the GW group (p lagophthalmos decreased postoperatively especially in the GW group. The beneficial effect of lid load surgeries result from a combination of a small increase on the spontaneous blink amplitude and a static effect due to the reduction of the distance between the lid margin and pupil center.

  4. Temporal dynamics of retinal and extraretinal signals in the FEFsem during smooth pursuit eye movements.

    Science.gov (United States)

    Bakst, Leah; Fleuriet, Jérome; Mustari, Michael J

    2017-05-01

    Neurons in the smooth eye movement subregion of the frontal eye field (FEFsem) are known to play an important role in voluntary smooth pursuit eye movements. Underlying this function are projections to parietal and prefrontal visual association areas and subcortical structures, all known to play vital but differing roles in the execution of smooth pursuit. Additionally, the FEFsem has been shown to carry a diverse array of signals (e.g., eye velocity, acceleration, gain control). We hypothesized that distinct subpopulations of FEFsem neurons subserve these diverse functions and projections, and that the relative weights of retinal and extraretinal signals could form the basis for categorization of units. To investigate this, we used a step-ramp tracking task with a target blink to determine the relative contributions of retinal and extraretinal signals in individual FEFsem neurons throughout pursuit. We found that the contributions of retinal and extraretinal signals to neuronal activity and behavior change throughout the time course of pursuit. A clustering algorithm revealed three distinct neuronal subpopulations: cluster 1 was defined by a higher sensitivity to eye velocity, acceleration, and retinal image motion; cluster 2 had greater activity during blinks; and cluster 3 had significantly greater eye position sensitivity. We also performed a comparison with a sample of medial superior temporal neurons to assess similarities and differences between the two areas. Our results indicate the utility of simple tests such as the target blink for parsing the complex and multifaceted roles of cortical areas in behavior.NEW & NOTEWORTHY The frontal eye field (FEF) is known to play a critical role in volitional smooth pursuit, carrying a variety of signals that are distributed throughout the brain. This study used a novel application of a target blink task during step ramp tracking to determine, in combination with a clustering algorithm, the relative contributions of

  5. Synthesis of Non-blinking Semiconductor Quantum Dots Emitting in the Near-Infrared

    Energy Technology Data Exchange (ETDEWEB)

    Dennis, Allison M. [Los Alamos National Laboratory; Mangum, Benjamin D. [Los Alamos National Laboratory; Piryatinski, Andrei [Los Alamos National Laboratory; Park, Young-Shin [Los Alamos National Laboratory; Htoon, Han [Los Alamos National Laboratory; Hollingsworth, Jennifer A. [Los Alamos National Laboratory

    2012-06-21

    Our previous work demonstrates that Quasi-Type II CdSe/CdS core-shell quantum dots with thick shells (3-5 nm) exhibit unique photophysical characteristics, including improved chemical robustness over typical thin-shelled core/shell systems and the elimination of blinking through suppression of nonradiative Auger recombination. Here we describe a new thick-shelled heterostructure, InP/CdS, which exhibits a Type II bandgap alignment producing near-infrared (NIR) emission. Samples with a range of shell thicknesses were synthesized, enabling shell-thickness-dependent study of the absorbance and emission spectra, fluorescence lifetimes, and quantum yields. InP/CdS/ZnS core/shell/shell structures were also synthesized to reduce cadmium exposure for applications in the biological environment. Single particle spectroscopy indicates reduced blinking and improved photostability with increasing shell thickness, resulting in thick-shelled dots that are appropriate for single-particle tracking measurements with NIR emission.

  6. The influence of stimulus sex and emotional expression on the attentional blink.

    Science.gov (United States)

    Stebbins, Hilary E; Vanous, Jesse B

    2015-08-01

    Past studies have demonstrated that angry faces used as the first target (T1) in an attentional blink paradigm interfere with processing of a second, neutral target (T2). However, despite research that suggests that the sex and emotional expression of a face are confounded, no study has investigated whether the sex of a stimulus might interact with emotional expression to influence the attentional blink. In the current study, both the sex and emotional expression of a T1 stimulus were manipulated to assess participants' ability to report the presences of a subsequent neutral target. Although the findings revealed limited evidence to support an interaction between sex and emotion, both the sex and emotional expression of the T1 stimulus were found to independently affect reporting of T2. These findings suggest that both emotional expression and stimulus sex are important in the temporal allocation of attentional resources to faces. (c) 2015 APA, all rights reserved).

  7. Active Bio-sensor System, Compatible with Arm Muscle Movement or Blinking Signals in BCI Application

    Directory of Open Access Journals (Sweden)

    Saeid Mehrkanoon

    2008-05-01

    Full Text Available This paper addresses a bionic active sensor system for the BCI application. Proposed system involves analog and digital parts. Two types of accurate sensors are used to pickup the blinking and muscle movement signals. A precision micro-power instrumentation amplifier with the adjustable gain, a sixth order low pass active filter with cutoff frequency 0.1 Hz, and a sixth order band pas filter with the bandwidth of 2-6 Hz are constructed to provide the clean blinking and arm muscle movement signals. TMS320C25 DSP processor is used for independent and unique command signals which are prepared for BCI application by a power amplifier and driver.

  8. Effects of monotherapy and polytherapy on the blink reflex in epileptic patients.

    Science.gov (United States)

    Lancman, M E; Cristiano, E; Golimstok, A; Granillo, R J

    1993-01-01

    We performed the blink reflex (BR) in 20 normal volunteers, 13 epileptic patients receiving antiepileptic drug (AED) monotherapy, and 13 epileptic patients receiving AED polytherapy. Comparison of R1, ipsilateral and contralateral R2 and VIIth nerve latencies in the three groups showed no statistically significant differences R1 and VIIth nerve latencies among the three groups. There were statistically significant differences between the polytherapy group and the monotherapy and control groups in comparisons of ipsilateral and contralateral R2. There were no significant differences between the monotherapy group and the control group for ipsilateral and contralateral R2. We hypothesized that AED polytherapy might interfere with synaptic transmission in the polysynaptic pathway of the blink reflex, prolonging the latency of R2. These results provide further evidence of the pathophysiologic effects associated with polytherapy in epileptic patients.

  9. Test-retest repeatability of the pupil light response to blue and red light stimuli in normal human eyes using a novel pupillometer

    DEFF Research Database (Denmark)

    Herbst, Kristina; Sander, Birgit; Milea, Dan;

    2011-01-01

    In this study, we evaluated the repeatability of pupil responses to colored light stimuli in healthy subjects using a prototype chromatic pupillometer. One eye of 10 healthy subjects was tested twice in the same day using monochromatic light exposure at two selected wavelengths (660 and 470 nm...... stimulation as the total area between a reference line representing baseline pupil size and the line representing actual pupil size over 20 s (area under the curve). There was no significant difference in the repeated measure compared to the first test for any of the pupil response parameters. In conclusion......, we have developed a novel prototype of color pupillometer which demonstrates good repeatability in evoking and recording the pupillary response to a bright blue and red light stimulus....

  10. Cortical source of blink-related delta oscillations and their correlation with levels of consciousness.

    Science.gov (United States)

    Bonfiglio, Luca; Olcese, Umberto; Rossi, Bruno; Frisoli, Antonio; Arrighi, Pieranna; Greco, Giovanni; Carozzo, Simone; Andre, Paolo; Bergamasco, Massimo; Carboncini, Maria Chiara

    2013-09-01

    Recently, blink-related delta oscillations (delta BROs) have been observed in healthy subjects during spontaneous blinking at rest. Delta BROs have been linked with continuous gathering of information from the surrounding environment, which is classically attributed to the precuneus. Furthermore, fMRI studies have shown that precuneal activity is reduced or missing when consciousness is low or absent. We therefore hypothesized that the source of delta BROs in healthy subjects could be located in the precuneus and that delta BROs could be absent or reduced in patients with disorders of consciousness (DOC). To test these hypotheses, electroencephalographic (EEG) activity at rest was recorded in 12 healthy controls and nine patients with DOC (four vegetative states, and five minimally conscious states). Three-second-lasting EEG epochs centred on each blink instance were analyzed in both time- (BROs) and frequency domains (event-related spectral perturbation or ERSP and intertrial coherence or ITC). Cortical sources of the maximum blink-related delta power, corresponding to the positive peak of the delta BROs, were estimated by standardized Low Resolution Electromagnetic Tomography. In control subjects, as expected, the source of delta BROs was located in the precuneus, whereas in DOC patients, delta BROs were not recognizable and no precuneal localization was possible. Furthermore, we observed a direct relationship between spectral indexes and levels of cognitive functioning in all subjects participating in the study. This reinforces the hypothesis that delta BROs reflect neural processes linked with awareness of the self and of the environment. Copyright © 2012 Wiley Periodicals, Inc., a Wiley company.

  11. Time to see the bigger picture: Individual differences in the attentional blink

    OpenAIRE

    Willems, Charlotte; Martens, Sander

    2015-01-01

    If two to-be-identified targets are presented in close temporal succession, identification for the second target is typically impaired. This attentional blink (AB) phenomenon has long been considered as a robust, universal cognitive limitation. However, more recent studies have demonstrated that AB task performance greatly differs between individuals, with some individuals even showing no AB in certain paradigms. Several studies have focused on these individual differences in an attempt to re...

  12. The Emotional Blink: Adult Age Differences in Visual Attention to Emotional Information

    OpenAIRE

    Langley, Linda K.; Rokke, Paul D.; Stark, Atiana C.; Saville, Alyson L.; Allen, Jaryn L.; Bagne, Angela G.

    2008-01-01

    To assess age differences in attention-emotion interactions, younger adults (ages 18–33 yrs) and older adults (ages 60–80 yrs) identified target words in a rapid serial visual presentation (RSVP) task. The second of two target words was neutral or emotional in content (positive in Experiment 1, negative in Experiment 2). In general, the ability to identify targets from a word stream declined with age. Age differences specific to the attentional blink were greatly reduced when baseline detecti...

  13. Painful faces-induced attentional blink modulated by top-down and bottom-up mechanisms

    OpenAIRE

    2015-01-01

    Pain-related stimuli can capture attention in an automatic (bottom-up) or intentional (top-down) fashion. Previous studies have examined attentional capture by pain-related information using spatial attention paradigms that involve mainly a bottom-up mechanism. In the current study, we investigated the pain information–induced attentional blink (AB) using a rapid serial visual presentation (RSVP) task, and compared the effects of task-irrelevant and task-relevant pain distractors. Relationshi...

  14. Painful faces-induced attentional blink modulated by top–down and bottom–up mechanisms

    OpenAIRE

    2015-01-01

    Pain-related stimuli can capture attention in an automatic (bottom–up) or intentional (top–down) fashion. Previous studies have examined attentional capture by pain-related information using spatial attention paradigms that involve mainly a bottom–up mechanism. In the current study, we investigated the pain information-induced attentional blink (AB) using a rapid serial visual presentation (RSVP) task, and compared the effects of task-irrelevant and task-relevant pain distractors. Relationshi...

  15. Effects of visual cortex activation on the nociceptive blink reflex in healthy subjects.

    Directory of Open Access Journals (Sweden)

    Simona L Sava

    Full Text Available Bright light can cause excessive visual discomfort, referred to as photophobia. The precise mechanisms linking luminance to the trigeminal nociceptive system supposed to mediate this discomfort are not known. To address this issue in healthy human subjects we modulated differentially visual cortex activity by repetitive transcranial magnetic stimulation (rTMS or flash light stimulation, and studied the effect on supraorbital pain thresholds and the nociceptive-specific blink reflex (nBR. Low frequency rTMS that inhibits the underlying cortex, significantly decreased pain thresholds, increased the 1st nBR block ipsi- and contralaterally and potentiated habituation contralaterally. After high frequency or sham rTMS over the visual cortex, and rMS over the right greater occipital nerve we found no significant change. By contrast, excitatory flash light stimulation increased pain thresholds, decreased the 1st nBR block of ipsi- and contralaterally and increased habituation contralaterally. Our data demonstrate in healthy subjects a functional relation between the visual cortex and the trigeminal nociceptive system, as assessed by the nociceptive blink reflex. The results argue in favour of a top-down inhibitory pathway from the visual areas to trigemino-cervical nociceptors. We postulate that in normal conditions this visuo-trigeminal inhibitory pathway may avoid disturbance of vision by too frequent blinking and that hypoactivity of the visual cortex for pathological reasons may promote headache and photophobia.

  16. Differential age-related changes in N170 responses to upright faces, inverted faces, and eyes in Japanese children

    Directory of Open Access Journals (Sweden)

    Kensaku eMiki

    2015-06-01

    Full Text Available The main objectives of this study were to investigate the development of face perception in Japanese children, focusing on the changes in face processing strategies (holistic and/or configural vs. feature-based that occur during childhood. To achieve this, we analyzed the face-related N170 component, evoked by upright face, inverted face, and eyes stimuli in 82 Japanese children aged between 8- and 13-years-old. During the experiment, the children were asked to perform a target detection task in which they were told to press a button when they saw images of faces or kettles with moustaches, glasses, and fake noses; i.e., an implicit face perception task. The N170 signals observed after the presentation of the upright face stimuli were longer in duration and/or had at least two peaks in the 8-11-year-old children, whereas those seen in the 12-13-year-old children were sharp and only had a single peak. N170 latency was significantly longer after the presentation of the eyes stimuli than after the presentation of the upright face stimuli in the 10- and 12-year-old children. In addition, significant differences in N170 latency were observed among all three stimulus types in the 13-year-old children. N170 amplitude was significantly greater after the presentation of the eyes stimuli than after the presentation of the upright face stimuli in the 8-10- and 12-year-old children. The results of the present study indicate that the upright face stimuli were processed using holistic and/or configural processing by the 13-year-old children.

  17. EALab (Eye Activity Lab): a MATLAB Toolbox for Variable Extraction, Multivariate Analysis and Classification of Eye-Movement Data.

    Science.gov (United States)

    Andreu-Perez, Javier; Solnais, Celine; Sriskandarajah, Kumuthan

    2016-01-01

    Recent advances in the reliability of the eye-tracking methodology as well as the increasing availability of affordable non-intrusive technology have opened the door to new research opportunities in a variety of areas and applications. This has raised increasing interest within disciplines such as medicine, business and education for analysing human perceptual and psychological processes based on eye-tracking data. However, most of the currently available software requires programming skills and focuses on the analysis of a limited set of eye-movement measures (e.g., saccades and fixations), thus excluding other measures of interest to the classification of a determined state or condition. This paper describes 'EALab', a MATLAB toolbox aimed at easing the extraction, multivariate analysis and classification stages of eye-activity data collected from commercial and independent eye trackers. The processing implemented in this toolbox enables to evaluate variables extracted from a wide range of measures including saccades, fixations, blinks, pupil diameter and glissades. Using EALab does not require any programming and the analysis can be performed through a user-friendly graphical user interface (GUI) consisting of three processing modules: 1) eye-activity measure extraction interface, 2) variable selection and analysis interface, and 3) classification interface.

  18. Disentangling the initiation from the response in joint attention: an eye-tracking study in toddlers with autism spectrum disorders.

    Science.gov (United States)

    Billeci, L; Narzisi, A; Campatelli, G; Crifaci, G; Calderoni, S; Gagliano, A; Calzone, C; Colombi, C; Pioggia, G; Muratori, F

    2016-05-17

    Joint attention (JA), whose deficit is an early risk marker for autism spectrum disorder (ASD), has two dimensions: (1) responding to JA and (2) initiating JA. Eye-tracking technology has largely been used to investigate responding JA, but rarely to study initiating JA especially in young children with ASD. The aim of this study was to describe the differences in the visual patterns of toddlers with ASD and those with typical development (TD) during both responding JA and initiating JA tasks. Eye-tracking technology was used to monitor the gaze of 17 children with ASD and 15 age-matched children with TD during the presentation of short video sequences involving one responding JA and two initiating JA tasks (initiating JA-1 and initiating JA-2). Gaze accuracy, transitions and fixations were analyzed. No differences were found in the responding JA task between children with ASD and those with TD, whereas, in the initiating JA tasks, different patterns of fixation and transitions were shown between the groups. These results suggest that children with ASD and those with TD show different visual patterns when they are expected to initiate joint attention but not when they respond to joint attention. We hypothesized that differences in transitions and fixations are linked to ASD impairments in visual disengagement from face, in global scanning of the scene and in the ability to anticipate object's action.

  19. Hypnotizability and Placebo Analgesia in Waking and Hypnosis as Modulators of Auditory Startle Responses in Healthy Women: An ERP Study

    Science.gov (United States)

    De Pascalis, Vilfredo; Scacchia, Paolo

    2016-01-01

    We evaluated the influence of hypnotizability, pain expectation, placebo analgesia in waking and hypnosis on tonic pain relief. We also investigated how placebo analgesia affects somatic responses (eye blink) and N100 and P200 waves of event-related potentials (ERPs) elicited by auditory startle probes. Although expectation plays an important role in placebo and hypnotic analgesia, the neural mechanisms underlying these treatments are still poorly understood. We used the cold cup test (CCT) to induce tonic pain in 53 healthy women. Placebo analgesia was initially produced by manipulation, in which the intensity of pain induced by the CCT was surreptitiously reduced after the administration of a sham analgesic cream. Participants were then tested in waking and hypnosis under three treatments: (1) resting (Baseline); (2) CCT-alone (Pain); and (3) CCT plus placebo cream for pain relief (Placebo). For each painful treatment, we assessed pain and distress ratings, eye blink responses, N100 and P200 amplitudes. We used LORETA analysis of N100 and P200 waves, as elicited by auditory startle, to identify cortical regions sensitive to pain reduction through placebo and hypnotic analgesia. Higher pain expectation was associated with higher pain reductions. In highly hypnotizable participants placebo treatment produced significant reductions of pain and distress perception in both waking and hypnosis condition. P200 wave, during placebo analgesia, was larger in the frontal left hemisphere while placebo analgesia, during hypnosis, involved the activity of the left hemisphere including the occipital region. These findings demonstrate that hypnosis and placebo analgesia are different processes of top-down regulation. Pain reduction was associated with larger EMG startle amplitudes, N100 and P200 responses, and enhanced activity within the frontal, parietal, and anterior and posterior cingulate gyres. LORETA results showed that placebo analgesia modulated pain-responsive areas

  20. Hypnotizability and Placebo Analgesia in Waking and Hypnosis as Modulators of Auditory Startle Responses in Healthy Women: An ERP Study.

    Science.gov (United States)

    De Pascalis, Vilfredo; Scacchia, Paolo

    2016-01-01

    We evaluated the influence of hypnotizability, pain expectation, placebo analgesia in waking and hypnosis on tonic pain relief. We also investigated how placebo analgesia affects somatic responses (eye blink) and N100 and P200 waves of event-related potentials (ERPs) elicited by auditory startle probes. Although expectation plays an important role in placebo and hypnotic analgesia, the neural mechanisms underlying these treatments are still poorly understood. We used the cold cup test (CCT) to induce tonic pain in 53 healthy women. Placebo analgesia was initially produced by manipulation, in which the intensity of pain induced by the CCT was surreptitiously reduced after the administration of a sham analgesic cream. Participants were then tested in waking and hypnosis under three treatments: (1) resting (Baseline); (2) CCT-alone (Pain); and (3) CCT plus placebo cream for pain relief (Placebo). For each painful treatment, we assessed pain and distress ratings, eye blink responses, N100 and P200 amplitudes. We used LORETA analysis of N100 and P200 waves, as elicited by auditory startle, to identify cortical regions sensitive to pain reduction through placebo and hypnotic analgesia. Higher pain expectation was associated with higher pain reductions. In highly hypnotizable participants placebo treatment produced significant reductions of pain and distress perception in both waking and hypnosis condition. P200 wave, during placebo analgesia, was larger in the frontal left hemisphere while placebo analgesia, during hypnosis, involved the activity of the left hemisphere including the occipital region. These findings demonstrate that hypnosis and placebo analgesia are different processes of top-down regulation. Pain reduction was associated with larger EMG startle amplitudes, N100 and P200 responses, and enhanced activity within the frontal, parietal, and anterior and posterior cingulate gyres. LORETA results showed that placebo analgesia modulated pain-responsive areas

  1. Prediction of risk and incidence of dry eye in critical patients1

    Science.gov (United States)

    de Araújo, Diego Dias; Almeida, Natália Gherardi; Silva, Priscila Marinho Aleixo; Ribeiro, Nayara Souza; Werli-Alvarenga, Andreza; Chianca, Tânia Couto Machado

    2016-01-01

    Objectives: to estimate the incidence of dry eye, to identify risk factors and to establish a risk prediction model for its development in adult patients admitted to the intensive care unit of a public hospital. Method: concurrent cohort, conducted between March and June, 2014, with 230 patients admitted to an intensive care unit. Data were analyzed by bivariate descriptive statistics, with multivariate survival analysis and Cox regression. Results: 53% out of 230 patients have developed dry eye, with onset mean time of 3.5 days. Independent variables that significantly and concurrently impacted the time for dry eye to occur were: O2 in room air, blinking more than five times per minute (lower risk factors) and presence of vascular disease (higher risk factor). Conclusion: dry eye is a common finding in patients admitted to adults intensive care units, and care for its prevention should be established. PMID:27192415

  2. Thermal analysis of dry eye subjects and the thermal impulse perturbation model of ocular surface.

    Science.gov (United States)

    Zhang, Aizhong; Maki, Kara L; Salahura, Gheorghe; Kottaiyan, Ranjini; Yoon, Geunyoung; Hindman, Holly B; Aquavella, James V; Zavislan, James M

    2015-03-01

    In this study, we explore the usage of ocular surface temperature (OST) decay patterns to distinguished between dry eye patients with aqueous deficient dry eye (ADDE) and meibomian gland dysfunction (MGD). The OST profiles of 20 dry eye subjects were measured by a long-wave infrared thermal camera in a standardized environment (24 °C, and relative humidity (RH) 40%). The subjects were instructed to blink every 5 s after 20 ∼ 25 min acclimation. Exponential decay curves were fit to the average temperature within a region of the central cornea. We find the MGD subjects have both a higher initial temperature (p thermal impulse perturbation (TIP) model. We conclude that long-wave-infrared thermal imaging is a plausible tool in assisting with the classification of dry eye patient.

  3. Your Eyes

    Science.gov (United States)

    ... people you know — like your grandparents — probably wear glasses. To the Brain! Think of the optic nerve as the great messenger in the back of your eye. The rods and cones of the retina change the colors and shapes you see into millions of nerve ...

  4. Values of blink reflex and electroneurography in diagnosis of facial paralysis

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    BACKGROUND:The electrophysiological test was mainly achieved by the reaction of nerve fiber to electrical stimulus,usually expressed by the amplitude and latency.Blink reflex and electroneurography (ENOG) are widely applied in facial paralysis,the amplitude would step down,and the latency would prolong when the facial nerve was injured.OBJECTIVE:To compare the value of blink reflex and ENOG in the diagnosis of facial paralysis (Bell's palsy).DESIGN:A controlled trial.SETTINGS:Affiliated Hospital,Chengdu University of Traditional Chinese Medicine;West China Hospital of Sichuan University;Mianyang Hospital of Traditional Chinese Medicine;Sichuan People's Hospital.PARTICIPANTS:The patients who had finished the tests of blink reflex (n=207) and ENOG (n=205) were selected from the Affiliated Hospital,Chengdu University of Traditional Chinese Medicine;West China Hospital of Sichuan University;Mianyang Hospital of Traditional Chinese Medicine;Sichuan People's Hospital from September 2001 to July 2003.After treatment for 4 weeks,the patients finished tests of blink reflex (n =207) and ENOG (n =205) were randomly divided into primary treatment group (n=68,69),acupuncture group (n =71,66) and comprehensive treatment group (n =68,70),respectively.Approval was obtained from the ethic committee of hospital.METHODS:Patients in the primary treatment group and acupuncture group were treated with western medicine,acupuncture and moxibustion alone respectively,and those in the comprehensive treatment group were treated with acupuncture and moxibustion based on western medicine.The whole period of treatment was 4 weeks.The tests of blink reflex and ENOG were carried out using Japanese light and electricity MEB-2200 electromyogram/induced potential instrument for once before and after treatment respectively.The normal value of the latency period of wave R1 was within 13 ms,and the difference was 1 - 1.2 ms between the left and right sides.MAIN OUTCOME MEASURES:The latency of wave Rl

  5. Response inhibition deficits in children with Fetal Alcohol Spectrum Disorder: Relationship between diffusion tensor imaging of the corpus callosum and eye movement control

    Directory of Open Access Journals (Sweden)

    Angelina Paolozza

    2014-01-01

    Full Text Available Response inhibition is the ability to suppress irrelevant impulses to enable goal-directed behavior. The underlying neural mechanisms of inhibition deficits are not clearly understood, but may be related to white matter connectivity, which can be assessed using diffusion tensor imaging (DTI. The goal of this study was to investigate the relationship between response inhibition during the performance of saccadic eye movement tasks and DTI measures of the corpus callosum in children with or without Fetal Alcohol Spectrum Disorder (FASD. Participants included 43 children with an FASD diagnosis (12.3 ± 3.1 years old and 35 typically developing children (12.5 ± 3.0 years old both aged 7–18, assessed at three sites across Canada. Response inhibition was measured by direction errors in an antisaccade task and timing errors in a delayed memory-guided saccade task. Manual deterministic tractography was used to delineate six regions of the corpus callosum and calculate fractional anisotropy (FA, mean diffusivity (MD, parallel diffusivity, and perpendicular diffusivity. Group differences in saccade measures were assessed using t-tests, followed by partial correlations between eye movement inhibition scores and corpus callosum FA and MD, controlling for age. Children with FASD made more saccade direction errors and more timing errors, which indicates a deficit in response inhibition. The only group difference in DTI metrics was significantly higher MD of the splenium in FASD compared to controls. Notably, direction errors in the antisaccade task were correlated negatively to FA and positively to MD of the splenium in the control, but not the FASD group, which suggests that alterations in connectivity between the two hemispheres of the brain may contribute to inhibition deficits in children with FASD.

  6. The attentional blink reveals serial working memory encoding: evidence from virtual and human event-related potentials.

    Science.gov (United States)

    Craston, Patrick; Wyble, Brad; Chennu, Srivas; Bowman, Howard

    2009-03-01

    Observers often miss a second target (T2) if it follows an identified first target item (T1) within half a second in rapid serial visual presentation (RSVP), a finding termed the attentional blink. If two targets are presented in immediate succession, however, accuracy is excellent (Lag 1 sparing). The resource sharing hypothesis proposes a dynamic distribution of resources over a time span of up to 600 msec during the attentional blink. In contrast, the ST(2) model argues that working memory encoding is serial during the attentional blink and that, due to joint consolidation, Lag 1 is the only case where resources are shared. Experiment 1 investigates the P3 ERP component evoked by targets in RSVP. The results suggest that, in this context, P3 amplitude is an indication of bottom-up strength rather than a measure of cognitive resource allocation. Experiment 2, employing a two-target paradigm, suggests that T1 consolidation is not affected by the presentation of T2 during the attentional blink. However, if targets are presented in immediate succession (Lag 1 sparing), they are jointly encoded into working memory. We use the ST(2) model's neural network implementation, which replicates a range of behavioral results related to the attentional blink, to generate "virtual ERPs" by summing across activation traces. We compare virtual to human ERPs and show how the results suggest a serial nature of working memory encoding as implied by the ST(2) model.

  7. Non-blinking (Zn)CuInS/ZnS Quantum Dots Prepared by In Situ Interfacial Alloying Approach

    Science.gov (United States)

    Zhang, Aidi; Dong, Chaoqing; Li, Liang; Yin, Jinjin; Liu, Heng; Huang, Xiangyi; Ren, Jicun

    2015-10-01

    Semiconductor quantum dots (QDs) are very important optical nanomaterials with a wide range of potential applications. However, blinking behavior of single QD is an intrinsic drawback for some biological and photoelectric applications based on single-particle emission. Herein we present a rational strategy for fabrication of non-blinking (Zn)CuInS/ZnS QDs in organic phase through in situ interfacial alloying approach. This new strategy includes three steps: synthesis of CuInS QDs, eliminating the interior traps of QDs by forming graded (Zn)CuInS alloyed QDs, modifying the surface traps of QDs by introducing ZnS shells onto (Zn)CuInS QDs using alkylthiols as sulfur source and surface ligands. The suppressed blinking mechanism was mainly attributed to modifying QDs traps from interior to exterior via a step-by-step modification. Non-blinking QDs show high quantum yield, symmetric emission spectra and excellent crystallinity, and will enable applications from biology to optoelectronics that were previously hindered by blinking behavior of traditional QDs.

  8. Why Do Eyes Water?

    Science.gov (United States)

    ... Lifesaver Kids Talk About: Coaches Why Do Eyes Water? KidsHealth > For Kids > Why Do Eyes Water? Print ... out of your nose. continue Why Do Eyes Water? Eyes water for lots of different reasons besides ...

  9. Eye muscle repair - discharge

    Science.gov (United States)

    ... Lazy eye repair - discharge; Strabismus repair - discharge; Extraocular muscle surgery - discharge ... You or your child had eye muscle repair surgery to correct eye muscle ... term for crossed eyes is strabismus. Children most often ...

  10. Why Do Eyes Water?

    Science.gov (United States)

    ... Happens in the Operating Room? Why Do Eyes Water? KidsHealth > For Kids > Why Do Eyes Water? A ... out of your nose. continue Why Do Eyes Water? Eyes water for lots of different reasons besides ...

  11. About the Eye

    Medline Plus

    Full Text Available ... eye behind the iris that helps to focus light on the retina. It allows the eye to ... of the eye. It regulates the amount of light entering the eye through the pupil. Pupil (PYOO- ...

  12. Recommended Sports Eye Protectors

    Science.gov (United States)

    ... Financial Assistance Information Vision Screening and Eye Exams Zika Virus and Vision Eye Problems Eye Problems Amblyopia ( ... Eye Health Report Reports and External Resources The Cost of Vision Problems The Future of Vision Vision ...

  13. Eye Safety at Home

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    ... Financial Assistance Information Vision Screening and Eye Exams Zika Virus and Vision Eye Problems Eye Problems Amblyopia ( ... Eye Health Report Reports and External Resources The Cost of Vision Problems The Future of Vision Vision ...

  14. Eye Safety at Work

    Science.gov (United States)

    ... Financial Assistance Information Vision Screening and Eye Exams Zika Virus and Vision Eye Problems Eye Problems Amblyopia ( ... Eye Health Report Reports and External Resources The Cost of Vision Problems The Future of Vision Vision ...

  15. Eye Movement Disorders

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    ... work properly. There are many kinds of eye movement disorders. Two common ones are Strabismus - a disorder in ... the eyes, sometimes called "dancing eyes" Some eye movement disorders are present at birth. Others develop over time ...

  16. About the Eye

    Medline Plus

    Full Text Available ... eye behind the iris that helps to focus light on the retina. It allows the eye to ... of the eye. It regulates the amount of light entering the eye through the pupil. Pupil (PYOO- ...

  17. Conjunctivitis (Pink Eye)

    Science.gov (United States)

    ... that can be embedded on web pages. Conjunctivitis (Pink Eye) One-Page Overview Pink, itchy eyes? Conjunctivitis – ... protect yourself from getting and spreading pink eye . Pink Eye: What To Do Discusses causes and treatment, ...

  18. Eye Disease Simulations

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    ... USAJobs Home > Eye Health Information > Eye Disease Simulations Eye Disease Simulations Age-Related Macular Degeneration Cataract Diabetic ... information page Back to top Diabetic Retinopathy Diabetic Eye Disease information page Back to top Glaucoma Glaucoma ...

  19. Eye Involvement in TSC

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    ... Privacy Policy Sitemap Learn Engage Donate About TSC Eyes Campbell (1905) first described the eye involvement in ... some form of eye involvement. Nonretinal and Retinal Eye Findings Facial angiofibromas may involve the eyelids of ...

  20. Eye Complications in IBD

    Science.gov (United States)

    ... Home > Resources > Eye Complications in IBD Go Back Eye Complications in IBD Email Print + Share Approximately 10% ... doctor’s attention sooner rather than later. TYPES OF EYE DISORDERS UVEITIS One of the most common eye ...

  1. Test-retest repeatability of the pupil light response to blue and red light stimuli in normal human eyes using a novel pupillometer

    Directory of Open Access Journals (Sweden)

    Kristina eHerbst

    2011-02-01

    Full Text Available In this study, we evaluated the repeatability of pupil responses to colored light stimuli in healthy subjects using a prototype chromatic pupillometer. One eye of 10 healthy subjects was tested twice in the same day using monochromatic light exposure at 2 selected wavelengths (660 nm and 470 nm, intensity 300 cd/m2 presented continuously for 20 seconds. Pupil responses were recorded in real time before, during and after light exposure. Maximal contraction amplitude and sustained contraction amplitude were calculated. In addition, we quantified the summed pupil response during continuous light stimulation as the total area between a reference line representing baseline pupil size and the line representing actual pupil size over 20 seconds (area under the curve. There was no significant difference in the repeated measure compared to the first test for any of the pupil response parameters. In conclusion, we have developed a novel prototype of color pupillometer which demonstrates good repeatability in evoking and recording the pupillary response to a bright blue and red light stimulus.

  2. Diagnosis of dry eye disease and emerging technologies

    Directory of Open Access Journals (Sweden)

    Zeev MSB

    2014-03-01

    Full Text Available Maya Salomon-Ben Zeev,1 Darby Douglas Miller,2,3 Robert Latkany1,21The Dry Eye Center at Physician Eyecare of New York, 2New York Eye and Ear Infirmary, 3Laser and Corneal Surgery Associates, New York, NY, USAAbstract: Dry eye is one of the most commonly encountered problems in ophthalmology. Signs can include punctate epithelial erosions, hyperemia, low tear lakes, rapid tear break-up time, and meibomian gland disease. Current methods of diagnosis include a slit-lamp examination with and without different stains, including fluorescein, rose bengal, and lissamine green. Other methods are the Schirmer test, tear function index, tear break-up time, and functional visual acuity. Emerging technologies include meniscometry, optical coherence tomography, tear film stability analysis, interferometry, tear osmolarity, the tear film normalization test, ocular surface thermography, and tear biomarkers. Patient-specific considerations involve relevant history of autoimmune disease, refractive surgery or use of oral medications, and allergies or rosacea. Other patient considerations include clinical examination for lid margin disease and presence of lagophthalmos or blink abnormalities. Given a complex presentation and a variety of signs and symptoms, it would be beneficial if there was an inexpensive, readily available, and reproducible diagnostic test for dry eye.Keywords: cornea, dry eye, tear film, stain

  3. Eye movement analysis for activity recognition using electrooculography.

    Science.gov (United States)

    Bulling, Andreas; Ward, Jamie A; Gellersen, Hans; Tröster, Gerhard

    2011-04-01

    In this work, we investigate eye movement analysis as a new sensing modality for activity recognition. Eye movement data were recorded using an electrooculography (EOG) system. We first describe and evaluate algorithms for detecting three eye movement characteristics from EOG signals-saccades, fixations, and blinks-and propose a method for assessing repetitive patterns of eye movements. We then devise 90 different features based on these characteristics and select a subset of them using minimum redundancy maximum relevance (mRMR) feature selection. We validate the method using an eight participant study in an office environment using an example set of five activity classes: copying a text, reading a printed paper, taking handwritten notes, watching a video, and browsing the Web. We also include periods with no specific activity (the NULL class). Using a support vector machine (SVM) classifier and person-independent (leave-one-person-out) training, we obtain an average precision of 76.1 percent and recall of 70.5 percent over all classes and participants. The work demonstrates the promise of eye-based activity recognition (EAR) and opens up discussion on the wider applicability of EAR to other activities that are difficult, or even impossible, to detect using common sensing modalities.

  4. Eye Contricks

    Directory of Open Access Journals (Sweden)

    Nicholas J Wade

    2011-06-01

    Full Text Available Pictorial images are icons as well as eye-cons: they provide distillations of objects or ideas into simpler shapes. They create the impression of representing that which cannot be presented. Even at the level of the photograph, the links between icon and object are tenuous. The dimensions of depth and motion are missing from icons, and these alone introduce all manner of potential ambiguities. The history of art can be considered as exploring the missing link between icon and object. Eye-cons can also be illusions—tricks of vision so that what is seen does not necessarily correspond to what is physically presented. Pictorial images can be spatialised or stylised; spatialised images generally share some of the projective characteristics of the object represented. Written words are also icons, but they do not resemble the objects they represent—they are stylised or conventional. Icons as stylised words and spatialised images were set in delightful opposition by René Magritte in a series of pipe paintings, and this theme is here alluded to. Most of visual science is now concerned with icons—two-dimensional displays on computer monitors. Is vision now the science of eye-cons?

  5. Somatosensory-evoked blink reflex in peripheral facial palsy

    Directory of Open Access Journals (Sweden)

    Sarah S El-Tawab

    2015-01-01

    Conclusion SBR occurs in patients with PFP and PFS and in healthy individuals. It has no relation with the clinical and electrophysiological changes occurring in PFP and PFS. Increased brainstem interneurons excitability is not essential to generate SBR. The hypothetical sensory-motor gating mechanism could be responsible for SBR generation.

  6. Feed Forward Neural Network Based Eye Localization and Recognition Using Hough Transform

    Directory of Open Access Journals (Sweden)

    Shylaja S S, K N Balasubramanya Murthy, S Natarajan Nischith, Muthuraj R, Ajay S

    2011-03-01

    Full Text Available Eye detection is a pre-requisite stage for many applications such as face recognition, iris recognition, eye tracking, fatigue detection based on eye-blink count and eye-directed instruction control. As the location of the eyes is a dominant feature of the face it can be used as an input to the face recognition engine. In this direction, the paper proposed here localizes eye positions using Hough Transformed (HT coefficients, which are found to be good at extracting geometrical components from any given object. The method proposed here uses circular and elliptical features of eyes in localizing them from a given face. Such geometrical features can be very efficiently extracted using the HT technique. The HT is based on a evidence gathering approach where the evidence is the ones cast in an accumulator array. The purpose of the technique is to find imperfect instances of objects within a certain class of shapes by a voting procedure. Feed forward neural network has been used for classification of eyes and non-eyes as the dimension of the data is large in nature. Experiments have been carried out on standard databases as well as on local DB consisting of gray scale images. The outcome of this technique has yielded very satisfactory results with an accuracy of 98.68%

  7. Both Trace and Delay Conditioning of Evaluative Responses Depend on Contingency Awareness

    Science.gov (United States)

    Kattner, Florian; Ellermeier, Wolfgang; Tavakoli, Paniz

    2012-01-01

    Whereas previous evaluative conditioning (EC) studies produced inconsistent results concerning the role of contingency knowledge, there are classical eye-blink conditioning studies suggesting that declarative processes are involved in trace conditioning but not in delay conditioning. In two EC experiments pairing neutral sounds (conditioned…

  8. Task demands modulate decision and eye movement responses in the chimeric face test: examining the right hemisphere processing account

    Directory of Open Access Journals (Sweden)

    Jason eCoronel

    2014-03-01

    Full Text Available A large and growing body of work, conducted in both brain-intact and brain-damaged populations, has used the free viewing chimeric face test as a measure of hemispheric dominance for the extraction of emotional information from faces. These studies generally show that normal right-handed individuals tend to perceive chimeric faces as more emotional if the emotional expression is presented on the half of the face to the viewer’s left (left hemiface. However, the mechanisms underlying this lateralized bias remain unclear. Here, we examine the extent to which this bias is driven by right hemisphere processing advantages versus default scanning biases in a unique way -- by changing task demands. In particular, we compare the original task with one in which right-hemisphere-biased processing cannot provide a decision advantage. Our behavioral and eye-movement data are inconsistent with the predictions of a default scanning bias account and support the idea that the left hemiface bias found in the chimeric face test is largely due to strategic use of right hemisphere processing mechanisms.

  9. Temporal correlation of blinking events in CdSe/ZnS and Si/SiO{sub 2} nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Bruhn, Benjamin, E-mail: b.bruhn@uva.nl [Materials and Nanophysics, KTH Royal Institute of Technology, 164 40 Kista (Sweden); Van der Waals-Zeeman Institute, University of Amsterdam, Science Park 904, 1098 XH Amsterdam (Netherlands); Qejvanaj, Fatjon [Materials and Nanophysics, KTH Royal Institute of Technology, 164 40 Kista (Sweden); Gregorkiewicz, Tom [Van der Waals-Zeeman Institute, University of Amsterdam, Science Park 904, 1098 XH Amsterdam (Netherlands); Linnros, Jan [Materials and Nanophysics, KTH Royal Institute of Technology, 164 40 Kista (Sweden)

    2014-11-15

    Well passivated single Si/SiO{sub 2} nanoparticles obey mono-exponential blinking statistics, whereas CdSe/ZnS quantum dots follow an apparent (truncated) power-law. Log-normal distributions are found to describe the interval length histograms at least as well as power-laws, while at the same time being more physically feasible and significantly easing the determination of the exponential cutoff in the ON-time distribution. The correlation of an ON- (OFF-)interval with its temporally displaced ON (OFF) neighbors, as well as that of intermixed intervals (ON with OFF and OFF with ON neighbors) has been studied. As expected from purely random processes, the correlation coefficients for events in silicon nanocrystals equal zero, whereas positive correlations between the pure and negative correlations between the mixed states in CdSe quantum dots hint at a switching process between two distinct blinking regimes that are slower than the blinking itself.

  10. As Far as the Eye Can See: Relationship between Psychopathic Traits and Pupil Response to Affective Stimuli.

    Science.gov (United States)

    Burley, Daniel T; Gray, Nicola S; Snowden, Robert J

    2017-01-01

    Psychopathic individuals show a range of affective processing deficits, typically associated with the interpersonal/affective component of psychopathy. However, previous research has been inconsistent as to whether psychopathy, within both offender and community populations, is associated with deficient autonomic responses to the simple presentation of affective stimuli. Changes in pupil diameter occur in response to emotionally arousing stimuli and can be used as an objective indicator of physiological reactivity to emotion. This study used pupillometry to explore whether psychopathic traits within a community sample were associated with hypo-responsivity to the affective content of stimuli. Pupil activity was recorded for 102 adult (52 female) community participants in response to affective (both negative and positive affect) and affectively neutral stimuli, that included images of scenes, static facial expressions, dynamic facial expressions and sound-clips. Psychopathic traits were measured using the Triarchic Psychopathy Measure. Pupil diameter was larger in response to negative stimuli, but comparable pupil size was demonstrated across pleasant and neutral stimuli. A linear relationship between subjective arousal and pupil diameter was found in response to sound-clips, but was not evident in response to scenes. Contrary to predictions, psychopathy was unrelated to emotional modulation of pupil diameter across all stimuli. The findings were the same when participant gender was considered. This suggests that psychopathy within a community sample is not associated with autonomic hypo-responsivity to affective stimuli, and this effect is discussed in relation to later defensive/appetitive mobilisation deficits.

  11. As Far as the Eye Can See: Relationship between Psychopathic Traits and Pupil Response to Affective Stimuli

    Science.gov (United States)

    Gray, Nicola S.; Snowden, Robert J.

    2017-01-01

    Psychopathic individuals show a range of affective processing deficits, typically associated with the interpersonal/affective component of psychopathy. However, previous research has been inconsistent as to whether psychopathy, within both offender and community populations, is associated with deficient autonomic responses to the simple presentation of affective stimuli. Changes in pupil diameter occur in response to emotionally arousing stimuli and can be used as an objective indicator of physiological reactivity to emotion. This study used pupillometry to explore whether psychopathic traits within a community sample were associated with hypo-responsivity to the affective content of stimuli. Pupil activity was recorded for 102 adult (52 female) community participants in response to affective (both negative and positive affect) and affectively neutral stimuli, that included images of scenes, static facial expressions, dynamic facial expressions and sound-clips. Psychopathic traits were measured using the Triarchic Psychopathy Measure. Pupil diameter was larger in response to negative stimuli, but comparable pupil size was demonstrated across pleasant and neutral stimuli. A linear relationship between subjective arousal and pupil diameter was found in response to sound-clips, but was not evident in response to scenes. Contrary to predictions, psychopathy was unrelated to emotional modulation of pupil diameter across all stimuli. The findings were the same when participant gender was considered. This suggests that psychopathy within a community sample is not associated with autonomic hypo-responsivity to affective stimuli, and this effect is discussed in relation to later defensive/appetitive mobilisation deficits. PMID:28118366

  12. Facial affect recognition in body dysmorphic disorder versus obsessive-compulsive disorder: An eye-tracking study.

    Science.gov (United States)

    Toh, Wei Lin; Castle, David J; Rossell, Susan L

    2015-10-01

    Body dysmorphic disorder (BDD) is characterised by repetitive behaviours and/or mental acts occurring in response to preoccupations with perceived defects or flaws in physical appearance (American Psychiatric Association, 2013). This study aimed to investigate facial affect recognition in BDD using an integrated eye-tracking paradigm. Participants were 21 BDD patients, 19 obsessive-compulsive disorder (OCD) patients and 21 healthy controls (HC), who were age-, sex-, and IQ-matched. Stimuli were from the Pictures of Facial Affect (Ekman & Friesen, 1975), and outcome measures were affect recognition accuracy as well as spatial and temporal scanpath parameters. Relative to OCD and HC groups, BDD patients demonstrated significantly poorer facial affect perception and an angry recognition bias. An atypical scanning strategy encompassing significantly more blinks, fewer fixations of extended mean durations, higher mean saccade amplitudes, and less visual attention devoted to salient facial features was found. Patients with BDD were substantially impaired in the scanning of faces, and unable to extract affect-related information, likely indicating deficits in basic perceptual operations. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Positive priming and intentional binding : Eye-blink rate predicts reward information effects on the sense of agency

    NARCIS (Netherlands)

    Aarts, Henk; Bijleveld, Erik; Custers, Ruud; Dogge, Myrthel; Deelder, Merel; Schutter, Dennis; van Haren, Neeltje E. M.

    2012-01-01

    Human society is strongly rooted in people's experiences of agency; that is, the pervasive feeling that one engages in voluntary behavior and causes one's own actions and resulting outcomes. Rewards and positive affect play an important role in the control of voluntary action. However, the role of p

  14. Positive priming and intentional binding: Eye-blink rate predicts reward information effects on the sense of agency

    NARCIS (Netherlands)

    Aarts, H.A.G.; Bijleveld, E.; Custers, R.; Dogge, M.; Deelder, M.; Schutter, D.J.L.G.; Haren, N.E.M. van

    2012-01-01

    Human society is strongly rooted in people's experiences of agency; that is, the pervasive feeling that one engages in voluntary behavior and causes one's own actions and resulting outcomes. Rewards and positive affect play an important role in the control of voluntary action. However, the role of p

  15. Eye Contricks

    Directory of Open Access Journals (Sweden)

    N Wade

    2011-04-01

    Full Text Available Icons are eye-cons: they provide a distillation of a complex object or idea into a simple pictorial shape. They create the impression of representing that which cannot be presented. Even at the level of the photograph, the links between icon and object are tenuous. The dimension of distance or depth is missing from the icon, and this alone introduces all manner of potential ambiguities. The history of art can be considered as an exploration of the missing link between icon and object. Eye-cons are more honest—they are tricks of vision so that what is seen does not necessarily correspond to what is presented. They are visual allusions rather than visual illusions, although they can display illusory effects. At its broadest, icon can be equated with image. The concept of image has thrived on its vagueness, and so attempts have been made to refine it. An icon corresponds to an optical image: it shares some of the projective characteristics of the object represented. Written words are also icons but they do not resemble the objects they represent—they are stylised or conventional rather than spatialised and projective. Words and images were set in delightful opposition by René Magritte (1898-1967 in a series of pipe paintings, and he also played on the theme of the arbitrariness of the verbal labels assigned to objects. What is surprising is that Magritte did not apply his painterly skills to transforming the word shapes he used. A similar reluctance to transform the typefaces pervades visual poetry. My interests are in the visual rather than the poetic dimension, and I will present a range of my own eye contricks which play with letter and word shapes in a variety of ways.

  16. Photonic mode density effects on single-molecule fluorescence blinking

    CERN Document Server

    Stefani, F D; Bocchio, N; Gaul, F; Pomozzi, A; Kreiter, M

    2006-01-01

    We investigated the influence of the photonic mode density (PMD) on the triplet dynamics of individual chromophores on a dielectric interface by comparing their response in the presence and absence of a nearby gold film. Lifetimes of the excited singlet state were evaluated in ordet to measure directly the PMD at the molecules position. Triplet state lifetimes were simultaneously determined by statistical analysis of the detection time of the fluorescence photons. The observed singlet decay rates are in agreement with the predicted PMD for molecules with different orientations. The triplet decay rate is modified in a fashion correlated to the singlet decay rate. These results show that PMD engineering can lead to an important suppression of the fluorescence, introducing a novel aspect of the physical mechanism to enhance fluorescence intensity in PMD-enhancing systems such as plasmonic devices.

  17. Blink restoration by the functional electrical stimulation in unilateral facial nerve palsy rabbits%功能性电刺激恢复周围性面神经麻痹兔眨眼功能的研究

    Institute of Scientific and Technical Information of China (English)

    薛玉斌; 冯国栋; 丁秀勇; 赵杨; 崔婷婷; 高志强

    2014-01-01

    兔的双侧同步眨眼.%Objective Tocompare the effects of different waveforms and parameters of electrical stimulation to elicit a blink,and construct a functional electrical stimulation (FES) system to restore synchronous blink in unilateral facial nerve palsy (FNP).Methods Firstly,twenty-four rabbits were surgically induced unilateral FNP and were divided into three groups,who received square,sine and triangle pulse wareforms,respectirely.Both the healthy and the paralysis eyelids of the rabbits received pulse train stimulation to produce a blink in both eyes.For each rabbit,twenty-seven combinations of frequencies (25 Hz,50 Hz and 100 Hz) and nine pulse widths (1-9 ms) were stimulated.The threshold amplitude and electric charge to elicit a blink was compared between different waveforms and different parameters.Secondly,a FES system was constructed to treat six surgically induced unilateral FNP rabbit chosen in the twenty-four rabbits,it consisted by an electromyogram (EMG) amplifier module which record the EMG of the healthy muscle,and a stimulator which received the EMG input and output a pulse train stimulation when triggered by the EMG.Results When the carrier frequency of the pulse train was 25 Hz,it was not able to induce a smooth blink.However,when the carrier frequencies were 50 Hz and 100 Hz,a smooth blink could be induced.The voltage required by 100 Hz was lower than 50 Hz,but it cost more electric charge.The amplitude that square waveforms required was far lower than sine and triangle,but the electric charge between the three waveforms was similar.Synchronous blink could be restored in the six unilateral FNP rabbits with the FES system.Conclusions To elicit a blink,square pulse train delivered in 50 Hz is a preferable option.The motion of the healthy eyelids as a source of information for stimulation of the paralyzed sides can restore the synchronous blink in unilateral FNP rabbits.

  18. TMS pulses on the frontal eye fields break coupling between visuospatial attention and eye movements

    NARCIS (Netherlands)

    Neggers, S.F.W.; Huijbers, W.; Vrijlandt, C.M.; Vlaskamp, B.N.S.; Schutter, D.J.L.G.; Kenemans, J.L.

    2007-01-01

    While preparing a saccadic eye movement, visual processing of the saccade goal is prioritized. Here, we provide evidence that the frontal eye fields (FEFs) are responsible for this coupling between eye movements and shifts of visuospatial attention. Functional magnetic resonance imaging ( fMRI)-guid

  19. Measurement of the hydrodynamic radius of quantum dots by fluorescence correlation spectroscopy excluding blinking.

    Science.gov (United States)

    de Thomaz, A A; Almeida, D B; Pelegati, V B; Carvalho, H F; Cesar, C L

    2015-03-19

    One of the most important properties of quantum dots (QDs) is their size. Their size will determine optical properties and in a colloidal medium their range of interaction. The most common techniques used to measure QD size are transmission electron microscopy (TEM) and X-ray diffraction. However, these techniques demand the sample to be dried and under a vacuum. This way any hydrodynamic information is excluded and the preparation process may alter even the size of the QDs. Fluorescence correlation spectroscopy (FCS) is an optical technique with single molecule sensitivity capable of extracting the hydrodynamic radius (HR) of the QDs. The main drawback of FCS is the blinking phenomenon that alters the correlation function implicating in a QD apparent size smaller than it really is. In this work, we developed a method to exclude blinking of the FCS and measured the HR of colloidal QDs. We compared our results with TEM images, and the HR obtained by FCS is higher than the radius measured by TEM. We attribute this difference to the cap layer of the QD that cannot be seen in the TEM images.

  20. Reaching back: the relative strength of the retroactive emotional attentional blink

    Science.gov (United States)

    Ní Choisdealbha, Áine; Piech, Richard M.; Fuller, John K.; Zald, David H.

    2017-01-01

    Visual stimuli with emotional content appearing in close temporal proximity either before or after a target stimulus can hinder conscious perceptual processing of the target via an emotional attentional blink (EAB). This occurs for targets that appear after the emotional stimulus (forward EAB) and for those appearing before the emotional stimulus (retroactive EAB). Additionally, the traditional attentional blink (AB) occurs because detection of any target hinders detection of a subsequent target. The present study investigated the relations between these different attentional processes. Rapid sequences of landscape images were presented to thirty-one male participants with occasional landscape targets (rotated images). For the forward EAB, emotional or neutral distractor images of people were presented before the target; for the retroactive EAB, such images were also targets and presented after the landscape target. In the latter case, this design allowed investigation of the AB as well. Erotic and gory images caused more EABs than neutral images, but there were no differential effects on the AB. This pattern is striking because while using different target categories (rotated landscapes, people) appears to have eliminated the AB, the retroactive EAB still occurred, offering additional evidence for the power of emotional stimuli over conscious attention. PMID:28255172

  1. Online Learners' Reading Ability Detection Based on Eye-Tracking Sensors.

    Science.gov (United States)

    Zhan, Zehui; Zhang, Lei; Mei, Hu; Fong, Patrick S W

    2016-09-10

    The detection of university online learners' reading ability is generally problematic and time-consuming. Thus the eye-tracking sensors have been employed in this study, to record temporal and spatial human eye movements. Learners' pupils, blinks, fixation, saccade, and regression are recognized as primary indicators for detecting reading abilities. A computational model is established according to the empirical eye-tracking data, and applying the multi-feature regularization machine learning mechanism based on a Low-rank Constraint. The model presents good generalization ability with an error of only 4.9% when randomly running 100 times. It has obvious advantages in saving time and improving precision, with only 20 min of testing required for prediction of an individual learner's reading ability.

  2. Online Learners’ Reading Ability Detection Based on Eye-Tracking Sensors

    Science.gov (United States)

    Zhan, Zehui; Zhang, Lei; Mei, Hu; Fong, Patrick S. W.

    2016-01-01

    The detection of university online learners’ reading ability is generally problematic and time-consuming. Thus the eye-tracking sensors have been employed in this study, to record temporal and spatial human eye movements. Learners’ pupils, blinks, fixation, saccade, and regression are recognized as primary indicators for detecting reading abilities. A computational model is established according to the empirical eye-tracking data, and applying the multi-feature regularization machine learning mechanism based on a Low-rank Constraint. The model presents good generalization ability with an error of only 4.9% when randomly running 100 times. It has obvious advantages in saving time and improving precision, with only 20 min of testing required for prediction of an individual learner’s reading ability. PMID:27626418

  3. The Social Responsibility of Retailers through the Eyes of Students of a Commerce Faculty – a Qualitative Approach

    Directory of Open Access Journals (Sweden)

    Gabriela Ţigu

    2014-02-01

    Full Text Available Retailers’ social responsibility is treated in the literature in association with such topics as trade justice, ethics, or fairness. The concept can be defined according to various dimensions, involving characteristics such as quality products, price fairness, honesty, and ethical interactions with consumers. This paper aims to evaluate students' attitude towards retailers’ social responsibility in implementing the strategic and tactical decisions about product, price, distribution and promotion. It is based on a qualitative research exploring the opinions of the students in business administration about this issue, both as consumers and prospective decision makers in the retail sector. The research was conducted in two focus groups, where the students played the roles of “consumers”, respectively “managers”. It was found out that there were differences in the responses of the two groups. The members of the “consumers” group were emotionally involved and they preferred a demand driven approach that focuses on finding solutions to their needs, while the members of the “managers” group have adopted a more detached attitude and they were concerned with the identification of gain as a consequence of social responsibility actions.

  4. 眼部动作实时识别系统设计%Design of Real-Time Blink Detection System

    Institute of Scientific and Technical Information of China (English)

    谢勤岚; 王西刚

    2011-01-01

    利用网络摄像机和图像处理单元设计了一种眼部动作实时识别系统.该系统首先用帧差法检测出眨眼的动作区域,将此区域设置成感兴趣区域,并用图像形态学算法对其进行处理;然后找出眼部轮廓,并以此区域创建模板,再利用此模板对每一帧图像进行模板匹配,找出匹配中的最小值,以得到识别的结果;最后通过实验验证了该算法的有效性.该系统有广泛的应用前景,如实现模拟鼠标的控制等.%A system based on network camera and image processing unit was designed to recognize eye movement real-time.Firstly,the region of blink,which is confirmed by difference in frame difference,is set as regions of interest(ROI),and then ROI is processed by morphological operation.Secondly,the eye contour is extracted to create a template region,which is used to mask image,and this template is used to match each frame in order to find the minimum to obtain recognition results.Finally,the validity of the algorithm was proved by experiment.The system has a wide range of applications such as control of the mouse,etc.

  5. Eye casualty services in London

    Science.gov (United States)

    Smith, H B; Daniel, C S; Verma, S

    2013-01-01

    The combined pressures of the European Working Time Directive, 4 h waiting time target, and growing rates of unplanned hospital attendances have forced a major consolidation of eye casualty departments across the country, with the remaining units seeing a rapid increase in demand. We examine the effect of these changes on the provision of emergency eye care in Central London, and see what wider lessons can be learned. We surveyed the managers responsible for each of London's 8 out-of-hours eye casualty services, analysed data on attendance numbers, and conducted detailed interviews with lead clinicians. At London's two largest units, Moorfields Eye Hospital and the Western Eye Hospital, annual attendance numbers have been rising at 7.9% per year (to 76 034 patients in 2010/11) and 9.6% per year (to 31 128 patients in 2010/11), respectively. Using Moorfields as a case study, we discuss methods to increase capacity and efficiency in response to this demand, and also examine some of the unintended consequences of service consolidation including patients travelling long distances to geographically inappropriate units, and confusion over responsibility for out-of-hours inpatient cover. We describe a novel ‘referral pathway' developed to minimise unnecessary travelling and delay for patients, and propose a forum for the strategic planning of London's eye casualty services in the future. PMID:23370420

  6. What Is Dry Eye?

    Medline Plus

    Full Text Available ... Tips & Prevention News Ask an Ophthalmologist Patient Stories Español Eye Health / Eye Health A-Z Dry Eye ... Eye Treatment What Is Dry Eye? Leer en Español: ¿Qué Es el Ojo Seco? Written By: Kierstan ...

  7. About the Eye

    Medline Plus

    Full Text Available ... Ask a Scientist Video Series Glossary The Visual System Your Eyes’ Natural Defenses Eye Health and Safety First Aid Tips Healthy Vision Tips Protective Eyewear Sports and Your Eyes Fun Stuff Cool Eye Tricks Links to More Information Optical Illusions Printables About the Eye Your eyes ...

  8. About the Eye

    Medline Plus

    Full Text Available ... Ask a Scientist Video Series Glossary The Visual System Your Eyes’ Natural Defenses Eye Health and Safety First Aid Tips Healthy Vision Tips Protective Eyewear Sports and Your Eyes Fun Stuff Cool Eye Tricks Links to More Information Optical Illusions Printables About the Eye Your eyes ...

  9. All eyes on the next generation of HIV vaccines: strategies for inducing a broadly neutralizing antibody response.

    Science.gov (United States)

    Ahlers, Jeffrey D

    2014-04-01

    HIV-1 broadly neutralizing antibodies (BNAbs) develop after several years of infection through a recursive process of memory B cell adaptation and maturation against co-evolving virus quasispecies. Advances in single-cell sorting and memory B cell antibody cloning methods have identified many new HIV BNAbs targeting conserved epitopes on the HIV envelope (env) protein. 3D crystal structures and biophysical analyses of BNAbs bound to invariant virus structures expressed on monomeric gp120, epitope scaffolds, core structures, and native trimers have helped us to visualize unique binding interactions and paratope orientations that have been instrumental in guiding vaccine design. A paradigm shift in the approach to structure-based design of HIV-1 envelope immunogens came recently after several laboratories discovered that native viral envelopes or "env-structures" reverse-engineered to bind with high affinity to a handful of broadly neutralizing antibodies did not in fact bind the predicted germline precursors of these broadly neutralizing antibodies. A major challenge for HIV-1 B cell vaccine development moving forward is the design of new envelope immunogens that can trigger the selection and expansion of germline precursor and intermediate memory B cells to recapitulate B cell ontogenies associated with the maturation of a broadly neutralizing antibody response. Equally important for vaccine development is the identification of delivery systems, prime-boost strategies, and synergistic adjuvant combinations that can induce the magnitude and quality of antigen-specific T follicular helper (TFH) cell responses needed to drive somatic hypermutation (SHM) and B cell maturation against heterologous primary virus envelopes. Finding the combination of multi-protein envelope immunogens and immunization strategies that can evolve a potent broadly neutralizing antibody response portends to require a complex vaccine regimen that might be difficult to implement on any scale

  10. Reanimation of the brow and eye in facial paralysis: Review of the literature and personal algorithmic approach.

    Science.gov (United States)

    Leckenby, J I; Ghali, S; Butler, D P; Grobbelaar, A O

    2015-05-01

    Facial palsy patients suffer an array of problems ranging from functional to psychological issues. With regard to the eye, lacrimation, lagophthalmos and the inability to spontaneously blink are the main symptoms and if left untreated can compromise the cornea and vision. There are a multitude of treatment modalities available and the surgeon has the challenging prospect of choosing the correct intervention to yield the best outcome for a patient. The accurate assessment of the eye in facial paralysis is described and by approaching the brow and the eye separately the treatment options and indications are discussed having been broken down into static and dynamic modalities. Based on our unit's experience of more than 35 years and 1000 cases of facial palsy, we have developed a detailed approach to help manage these patients optimally. The aim of this article is to provide the reader with a systematic algorithm that can be used when consulting a patient with eye problems associated with facial palsy.

  11. Under which conditions does T1 difficulty affect T2 performance in the attentional blink?

    DEFF Research Database (Denmark)

    Nielsen, Simon; Petersen, Anders; Andersen, Tobias

    When two visual targets (T1 & T2) are presented in rapid succession, performance of T2 suffers up to 900 ms. One theory of this attentional blink (Raymond, Shapiro, & Arnell, 1992) propose that T1 and T2 compete for limited processing resources (Chun & Potter, 1995), and predict that prolonging...

  12. Multi-level approach to anaesthetic effects produced by sevoflurane or propofol in humans : 1. BIS and blink reflex

    NARCIS (Netherlands)

    Mourisse, J.; Lerou, J.; Struys, M.; Zwarts, M.; Booij, L.

    2007-01-01

    Background. The relative roles of forebrain and brainstem in producing adequate anaesthesia are unclear. Methods. We simultaneously analysed the effects of sevoflurane (Group S; n = 18) or propofol (Group P; n = 29) on the bispectral index (BIS) and the first component of the blink reflex (RI). The

  13. Multi-level approach to anaesthetic effects produced by sevoflurane or propofol in humans: 1. BIS and blink reflex.

    NARCIS (Netherlands)

    Mourisse, J.M.J.; Lerou, J.G.C.; Struys, M.; Zwarts, M.J.; Booij, L.H.D.J.

    2007-01-01

    BACKGROUND: The relative roles of forebrain and brainstem in producing adequate anaesthesia are unclear. METHODS: We simultaneously analysed the effects of sevoflurane (Group S; n = 18) or propofol (Group P; n = 29) on the bispectral index (BIS) and the first component of the blink reflex (R1). The

  14. On the Labile Memory Buffer in the Attentional Blink: Masking the T2 Representation by Onset Transients Mediates the AB

    Science.gov (United States)

    Jannati, Ali; Spalek, Thomas M.; Di Lollo, Vincent

    2011-01-01

    Report of a second target (T2) is impaired when presented within 500 ms of the first (T1). This attentional blink (AB) is known to cause a delay in T2 processing during which T2 must be stored in a labile memory buffer. We explored the buffer's characteristics using different types of masks after T2. These characteristics were inferred by…

  15. On the Labile Memory Buffer in the Attentional Blink: Masking the T2 Representation by Onset Transients Mediates the AB

    Science.gov (United States)

    Jannati, Ali; Spalek, Thomas M.; Di Lollo, Vincent

    2011-01-01

    Report of a second target (T2) is impaired when presented within 500 ms of the first (T1). This attentional blink (AB) is known to cause a delay in T2 processing during which T2 must be stored in a labile memory buffer. We explored the buffer's characteristics using different types of masks after T2. These characteristics were inferred by…

  16. Lag-1 sparing in the attentional blink : Benefits and costs of integrating two events into a single episode

    NARCIS (Netherlands)

    Hommel, Bernhard; Akyürek, Elkan G

    2005-01-01

    When people monitor a visual stream of rapidly presented stimuli for two targets (T1 and T2), they often miss T2 if it falls into a time window of about half a second after T1 onset--the attentional blink. However, if T2 immediately follows T1, performance is often reported being as good as that at

  17. EyeGENE

    Data.gov (United States)

    U.S. Department of Health & Human Services — The eyeGENE® Biorepository and corresponding Database contain family history and clinical eye exam data from subjects enrolled in eyeGENE® Program coupled to...

  18. Eye Injuries in Sports

    Science.gov (United States)

    ... in Sports Which sports cause the most eye injuries?Sports cause more than 40,000 eye injuries each ... and racquet sports.When it comes to eye injuries, sports can be classified as low risk, high risk ...

  19. What Is Dry Eye?

    Medline Plus

    Full Text Available ... Member Services Advocacy Foundation About Subspecialties & More Eye Health Home Annual Meeting Clinical Education Practice Management Member ... Center Redmond Ethics Center Global Ophthalmology Guide Eye Health Find an Ophthalmologist Academy Store Eye Health A- ...

  20. What Is Dry Eye?

    Medline Plus

    Full Text Available ... Member Services Advocacy Foundation About Subspecialties & More Eye Health Home Annual Meeting Clinical Education Practice Management Member ... Center Redmond Ethics Center Global Ophthalmology Guide Eye Health Find an Ophthalmologist Academy Store Eye Health A- ...

  1. Eye muscle repair - slideshow

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/presentations/100062.htm Eye muscle repair - series—Normal anatomy To use the sharing ... the eyeball to the eye socket. The external muscles of the eye are found behind the conjunctiva. ...

  2. Pink Eye (Conjunctivitis)

    Science.gov (United States)

    ... you have allergic conjunctivitis. Preventing the spread of pink eye Practice good hygiene to control the spread ... can return to school or child care. Preventing pink eye in newborns Newborns' eyes are susceptible to ...

  3. About the Eye

    Medline Plus

    Full Text Available ... Glossary The Visual System Your Eyes’ Natural Defenses Eye Health and Safety First Aid Tips Healthy Vision ... to More Information Optical Illusions Printables About the Eye Your eyes are made up of many different ...

  4. About the Eye

    Science.gov (United States)

    ... Glossary The Visual System Your Eyes’ Natural Defenses Eye Health and Safety First Aid Tips Healthy Vision ... to More Information Optical Illusions Printables About the Eye Your eyes are made up of many different ...

  5. Eye Injuries (For Parents)

    Science.gov (United States)

    ... Habits for TV, Video Games, and the Internet Eye Injuries KidsHealth > For Parents > Eye Injuries Print A ... sand, dirt, and other foreign bodies on the eye surface) Wash your hands thoroughly before touching the ...

  6. Eye movement monitoring of memory.

    Science.gov (United States)

    Ryan, Jennifer D; Riggs, Lily; McQuiggan, Douglas A; McQuiggan, Doug

    2010-08-15

    Explicit (often verbal) reports are typically used to investigate memory (e.g. "Tell me what you remember about the person you saw at the bank yesterday."), however such reports can often be unreliable or sensitive to response bias, and may be unobtainable in some participant populations. Furthermore, explicit reports only reveal when information has reached consciousness and cannot comment on when memories were accessed during processing, regardless of whether the information is subsequently accessed in a conscious manner. Eye movement monitoring (eye tracking) provides a tool by which memory can be probed without asking participants to comment on the contents of their memories, and access of such memories can be revealed on-line. Video-based eye trackers (either head-mounted or remote) use a system of cameras and infrared markers to examine the pupil and corneal reflection in each eye as the participant views a display monitor. For head-mounted eye trackers, infrared markers are also used to determine head position to allow for head movement and more precise localization of eye position. Here, we demonstrate the use of a head-mounted eye tracking system to investigate memory performance in neurologically-intact and neurologically-impaired adults. Eye movement monitoring procedures begin with the placement of the eye tracker on the participant, and setup of the head and eye cameras. Calibration and validation procedures are conducted to ensure accuracy of eye position recording. Real-time recordings of X,Y-coordinate positions on the display monitor are then converted and used to describe periods of time in which the eye is static (i.e. fixations) versus in motion (i.e., saccades). Fixations and saccades are time-locked with respect to the onset/offset of a visual display or another external event (e.g. button press). Experimental manipulations are constructed to examine how and when patterns of fixations and saccades are altered through different types of prior

  7. I spy with my little eye: detection of temporal violations in event sequences and the pupillary response.

    Science.gov (United States)

    Raisig, Susanne; Welke, Tinka; Hagendorf, Herbert; van der Meer, Elke

    2010-04-01

    Scripts of familiar activities store the temporal order of events. This enables us to generate predictions about which event will follow another. When an event does not unfold in the chronological order, a mismatch arises between the predictions and the external sensory input which is perceived as a conflict. The detection of this mismatch is accomplished by a comparison mechanism (Zacks et al., 2007; Barsalou, 2009). We have applied pupillometry to investigate the nature of this comparison process. We further tested for individual differences in the efficiency of the mismatch detection. Participants were presented the title of an event sequence to trigger predictions about the order in which events would unfold. Subsequently, three script events were presented one at a time. The events either unfolded in the correct chronological order or included temporal violations at different points within the event triplet. Violations of the temporal order had to be detected. As soon as it was detected, the trial had to be terminated. We found that a temporal violation elicited a large pupillary response in all individuals indicating that the comparison between the predictions and the external sensory input was accomplished online and worked equally well for all individuals. However, not all individuals terminated the trial after having detected the violation. Results showed that efficient individuals who responded adequately had a greater pupillary response than inefficient individuals suggesting that they invested more cognitive resources. The results are discussed in light of theories of behavioral performance and conflict-monitoring.

  8. A novel EOG/EEG hybrid human-machine interface adopting eye movements and ERPs: application to robot control.

    Science.gov (United States)

    Ma, Jiaxin; Zhang, Yu; Cichocki, Andrzej; Matsuno, Fumitoshi

    2015-03-01

    This study presents a novel human-machine interface (HMI) based on both electrooculography (EOG) and electroencephalography (EEG). This hybrid interface works in two modes: an EOG mode recognizes eye movements such as blinks, and an EEG mode detects event related potentials (ERPs) like P300. While both eye movements and ERPs have been separately used for implementing assistive interfaces, which help patients with motor disabilities in performing daily tasks, the proposed hybrid interface integrates them together. In this way, both the eye movements and ERPs complement each other. Therefore, it can provide a better efficiency and a wider scope of application. In this study, we design a threshold algorithm that can recognize four kinds of eye movements including blink, wink, gaze, and frown. In addition, an oddball paradigm with stimuli of inverted faces is used to evoke multiple ERP components including P300, N170, and VPP. To verify the effectiveness of the proposed system, two different online experiments are carried out. One is to control a multifunctional humanoid robot, and the other is to control four mobile robots. In both experiments, the subjects can complete tasks effectively by using the proposed interface, whereas the best completion time is relatively short and very close to the one operated by hand.

  9. An autoimmune response to OBP1a is associated with dry eye in the Aire-deficient mouse

    Science.gov (United States)

    DeVoss, Jason J; LeClair, Norbert; Hou, Yafei; Grewal, Navdeep; Johannes, Kellsey; Lu, Wen; Yang, Ting; Meagher, Craig; Fong, Lawrence; Strauss, Erich C.; Anderson, Mark S.

    2010-01-01

    Sjögren’s Syndrome is a human autoimmune disease characterized by immune-mediated destruction of the lacrimal and salivary glands. Here, we show that the Aire-deficient mouse represents a new tool to investigate autoimmune dacryoadenitis and keratoconjunctivitis sicca, features of Sjögren’s Syndrome. Previous work in the Aire-deficient mouse suggested a role for alpha-fodrin, a ubiquitous antigen, in the disease process. Using an unbiased biochemical approach, however, we have identified a novel lacrimal gland autoantigen, odorant binding protein 1a, targeted by the autoimmune response. This novel autoantigen is expressed in the thymus in an Aire-dependent manner. The results from our study suggest that defects in central tolerance may contribute to Sjögren’s Syndrome and provide a new and clinically relevant model to investigate the pathogenic mechanisms in lacrimal gland autoimmunity and associated ocular surface sequelae. PMID:20237294

  10. Laser photocoagulation - eye

    Science.gov (United States)

    Laser coagulation; Laser eye surgery; Photocoagulation; Laser photocoagulation - diabetic eye disease; Laser photocoagulation - diabetic retinopathy; Focal photocoagulation; Scatter (or pan retinal) photocoagulation; Proliferative ...

  11. A vermal Purkinje cell simple spike population response encodes the changes in eye movement kinematics due to smooth pursuit adaptation.

    Directory of Open Access Journals (Sweden)

    Suryadeep eDash

    2013-03-01

    Full Text Available Smooth pursuit adaptation (SPA is an example of cerebellum-dependent motor learning that depends on the integrity of the oculomotor vermis (OMV. In an attempt to unveil the neuronal basis of the role of the OMV in SPA, we recorded Purkinje cells simple spikes (PC SS of trained monkeys. Individual PC SS exhibited specific changes of their discharge patterns during the course of SPA. However, these individual changes did not provide a reliable explanation of the behavioural changes. On the other hand, the population response of PC SS perfectly reflected the changes resulting from adaptation. Population vector was calculated using all cells recorded independent of their location. A population code conveying the behavioural changes is in full accordance with the anatomical convergence of PC axons on target neurons in the cerebellar nuclei. Its computational advantage is the ease with which it can be adjusted to the needs of the behavior by changing the contribution of individual PC SS based on error feedback.

  12. Diagnosing dry eye with dynamic-area high-speed videokeratoscopy

    Science.gov (United States)

    Alonso-Caneiro, David; Turuwhenua, Jason; Iskander, D. Robert; Collins, Michael J.

    2011-07-01

    Dry eye syndrome is one of the most commonly reported eye health conditions. Dynamic-area high-speed videokeratoscopy (DA-HSV) represents a promising alternative to the most invasive clinical methods for the assessment of the tear film surface quality (TFSQ), particularly as Placido-disk videokeratoscopy is both relatively inexpensive and widely used for corneal topography assessment. Hence, improving this technique to diagnose dry eye is of clinical significance and the aim of this work. First, a novel ray-tracing model is proposed that simulates the formation of a Placido image. This model shows the relationship between tear film topography changes and the obtained Placido image and serves as a benchmark for the assessment of indicators of the ring's regularity. Further, a novel block-feature TFSQ indicator is proposed for detecting dry eye from a series of DA-HSV measurements. The results of the new indicator evaluated on data from a retrospective clinical study, which contains 22 normal and 12 dry eyes, have shown a substantial improvement of the proposed technique to discriminate dry eye from normal tear film subjects. The best discrimination was obtained under suppressed blinking conditions. In conclusion, this work highlights the potential of the DA-HSV as a clinical tool to diagnose dry eye syndrome.

  13. Wartime open globe eye injuries.

    Science.gov (United States)

    Plestina-Borjan, Ivna; Medvidovic-Grubisic, Maria; Zuljan, Igor; Lakos, Venera; Miljak, Snjezana; Markovic, Irena; Ivanisevic, Milan

    2010-03-01

    Open globe injuries are the most serious eye injuries in war as in peace time. The purpose of this study is to analyze wartime open globe eye injuries in 72 patients treated at the Department of Ophthalmology, Clinical Hospital of Split from July 1991 to April 1993, during the intensive war in Croatia and Bosnia and Herzegovina, and to evaluate crucial factors responsible for the functional success of the treatment. Wartime open globe eye injuries were retrospectively analyzed in 72 patients (80 eyes) hospitalized at Clinical Hospital of Split, Department of Ophthalmology, between July 1991 and April 1993. The causes and ways of wounding, localization of wounds and presence, nature and localization of the foreign body, as well as admission time, microsurgical management and other factors contributing to poor visual outcome were studied. Standard international classification of ocular traumas (the Birmingham Eye Trauma Terminology and the International Ocular Trauma Classification) was used for the classified and graded injuries. Open globe eye injuries amounted to 52.65% of all war injuries to the eyes. Bilateral injuries were found in eight patients (11.11%). The most frequent cause of the injures were fragments of explosive devices (more than two-thirds). Most of the patients were admitted to the hospital within 24 hours of the injury. Using current microsurgical techniques, the attempt was made to achieve not only anatomical but also functional recovery already in the primary treatment. In 30 eyes (37.50%) final visual acuity amounted to more than 0.1, and in 22 eyes (27.50%) it reached 0.5. There was a statistically significant correlation between admission within the first 12 hours and postoperative improved visual acuity (chi(2) = 4.53; p = 0.033). Statistically significantly better visual acuity was found in patients with lesions limited to the anterior segment of the eye. Primary enucleation or evisceration was performed only exceptionally: one enucleation

  14. Noisy cooperative intermittent processes: From blinking quantum dots to human consciousness

    Energy Technology Data Exchange (ETDEWEB)

    Allegrini, Paolo; Paradisi, Paolo; Menicucci, Danilo; Bedini, Remo; Gemignani, Angelo [Istituto di Fisiologia Clinica (IFC-CNR), Via Moruzzi 1, 56124 Pisa (Italy); Fronzoni, Leone, E-mail: allegrini@ifc.cnr.it [Dipartimento di Fisica ' E. Fermi' -Universita di Pisa and INFM CRS-SOFT, Largo Pontecorvo 3, 56127 Pisa (Italy)

    2011-07-08

    We study the superposition of a non-Poisson renewal process with the presence of a superimposed Poisson noise. The non-Poisson renewals mark the passage between meta-stable states in system with self-organization. We propose methods to measure the amount of information due to the two independent processes independently, and we see that a superficial study based on the survival probabilities yield stretched-exponential relaxations. Our method is in fact able to unravel the inverse-power law relaxation of the isolated non-Poisson processes, even when noise is present. We provide examples of this behavior in system of diverse nature, from blinking nano-crystals to weak turbulence. Finally we focus our discussion on events extracted from human electroencephalograms, and we discuss their connection with emerging properties of integrated neural dynamics, i.e. consciousness.

  15. The temporal locus of the interaction between working memory consolidation and the attentional blink.

    Science.gov (United States)

    Akyürek, Elkan G; Leszczyński, Marcin; Schubö, Anna

    2010-11-01

    An increase in concurrent working memory load has been shown to amplify the attentional blink. The present study investigated the temporal locus of this phenomenon, by using a dual rapid serial visual presentation paradigm that enabled the measurement of lateralized event-related potentials. The P3 component was shown to be affected by both working memory load and the lag between the target stimuli, consistent with current models of temporal attention and a functional explanation of the P3 in terms of memory consolidation. P3 amplitude was reduced for short target lags and high memory loads. The P2 component was affected by lag only, and not memory load. Importantly, the N2pc component was modulated also by both lag and memory load. The results showed that early attentional processing (as marked by the N2pc) was suppressed by increased involvement of working memory, a phenomenon not well predicted by many current theories of temporal attention.

  16. The emotional blink: adult age differences in visual attention to emotional information.

    Science.gov (United States)

    Langley, Linda K; Rokke, Paul D; Stark, Atiana C; Saville, Alyson L; Allen, Jaryn L; Bagne, Angela G

    2008-12-01

    To assess age differences in attention-emotion interactions, the authors asked young adults (ages 18-33 years) and older adults (ages 60-80 years) to identify target words in a rapid serial visual presentation (RSVP) task. The second of two target words was neutral or emotional in content (positive in Experiment 1, negative in Experiment 2). In general, the ability to identify targets from a word stream declined with age. Age differences specific to the attentional blink were greatly reduced when baseline detection accuracy was equated between groups. With regard to emotion effects, older adults showed enhanced identification of both positive and negative words relative to neutral words, whereas young adults showed enhanced identification of positive words and reduced identification of negative words. Together these findings suggest that the nature of attention-emotion interactions changes with age, but there was little support for a motivational shift consistent with emotional regulation goals at an early stage of cognitive processing.

  17. The Attentional Blink Paradigm in Individuals with High and Low Levels of Depression and Anxiety

    Directory of Open Access Journals (Sweden)

    Hannah Kathleen Skinner

    2014-12-01

    Full Text Available The attentional biases of individuals with high and low levels of depression and anxiety were tested using the Attentional Blink paradigm. A rapid serial visual presentation (RSVP task was used to detect biases in identification of emotionally valenced target images. The independent variables were depression, anxiety, lag of target stimulus, and emotional valence of target images. The dependent variables were accuracy, reaction times, and pupil dilation. As predicted, attentional biases were found for symptoms of both depression and anxiety, independently and co-morbidly, for dependent variables. The data suggest that there are both differences and similarities in the effects of symptoms of anxiety and depression on attentional biases around emotional stimuli.

  18. Zolmitriptan reverses blink reflex changes induced during the migraine attack in humans.

    Science.gov (United States)

    de Tommaso, M; Guido, M; Libro, G; Sciruicchio, V; Puca, F

    2000-07-28

    The question about the 5-hydroxytryptamine (5-HT)(1B-1D) receptors agonists, if the clinical efficacy in migraine attacks is linked with the action at the central level or at the peripheral one, is still unresolved. We evaluated the effects of zolmitriptan and sumatriptan on blink reflex in thirty migraine without aura patients during the attacks in order to assess the central action on the trigeminal system. Both drugs were effective in reducing headache severity compared to placebo. In the migraine attack an increased area of the R3 component on the pain side was observed; it was suppressed by zolmitriptan, which confirmed its action on the central trigeminal circuits, though the clinical relevance of this effect could be questioned.

  19. Noisy cooperative intermittent processes: From blinking quantum dots to human consciousness

    Science.gov (United States)

    Allegrini, Paolo; Paradisi, Paolo; Menicucci, Danilo; Bedini, Remo; Gemignani, Angelo; Fronzoni, Leone

    2011-07-01

    We study the superposition of a non-Poisson renewal process with the presence of a superimposed Poisson noise. The non-Poisson renewals mark the passage between meta-stable states in system with self-organization. We propose methods to measure the amount of information due to the two independent processes independently, and we see that a superficial study based on the survival probabilities yield stretched-exponential relaxations. Our method is in fact able to unravel the inverse-power law relaxation of the isolated non-Poisson processes, even when noise is present. We provide examples of this behavior in system of diverse nature, from blinking nano-crystals to weak turbulence. Finally we focus our discussion on events extracted from human electroencephalograms, and we discuss their connection with emerging properties of integrated neural dynamics, i.e. consciousness.

  20. 儿童异常瞬目综合征的诊治%Etiologies and treatments of abnormal blinking in children

    Institute of Scientific and Technical Information of China (English)

    杜芬; 郭燕; 张金梅; 陶利娟

    2015-01-01

    corresponding treatments, according to the result of interrogation and examination of eyes were analyzed and the therapeutic effect was observed. ?RESULTS:Totally, 5 561 cases were collected into the study including 4 025 cases of male, 1536 cases of female, and the ratio was 2.6∶1;age range was 2 ~14 years old with average age was ( 6.9 ±0.6 ) years old.Etiologies were as follows: refractive ( hyperopia, myopia and astigmatism) 2054 cases ( 36.9%);allergic conjunctivitis 1670 cases (30.0%);children dry eyes 982 cases (17.7%);partial eclipse children with 605 cases ( 10.9%);lead pollution 590 care (10.6%);strabismus 156 cases (2.8%);trichiasis with 129 cases (2.3%);trace element deficiency ( calcium, iron, zinc, magnesium and copper) for a total of 102 cases (1.8%);chalazion 37 cases (0.7%);keratitis and corneal injury 24 cases (0.4%), palpebral dermatitis, allergic rhinitis, dermatitis, 37 cases (0.7%);conjunctival stone 8 cases (0.1%);tic disorders of 30 patients (0.5%), asthenopia of 6 cases (0.1%);lacrimal duct obstruction, dacryocystitis 9 cases (0.1%).The etiologies of children with abnormal blinking were not caused by single factors. After examination, its etiology in children was resulted by one kind or more of a combination of factors.All of them were carried out ear acupoint application therapy and psychological intervention therapy, and symptomatic treatment was given after finding the cause.Following all the cases 1~3mo, blinking can obviously relieve,in which 4 560 cases ( 81.9%) were cured, 5286 cares were improved, the recovery ( including cured ) was 95.1%;slightly improved ( including relapse cases ) 102 cases (1.8%);No significant changes in 173 cases (3.1%). ?CONCLUSION:A variety of causes that can lead to children's abnormal blinking, refractive error, allergic conjunctivitis and children's dry eyes as the main reason. According to different causes to carry on the comprehensive treatments can get better treatment effect.

  1. Distraction by emotion in early adolescence: affective facilitation and interference during the attentional blink

    Directory of Open Access Journals (Sweden)

    Sabine eHeim

    2013-09-01

    Full Text Available This study examined the extent to which early adolescents (aged 10 to 13 years differ from adults in their sensitivity to attention capture by affective stimuli during rapid processing. A rapid serial visual presentation paradigm (RSVP was implemented as a dual task, requiring the report of two green target stimuli embedded in a stream of distractors. Known as the attentional blink (AB, task performance is typically impaired when the first and second targets (T1 and T2, respectively are separated by at least one distractor and about 200 ms of time. Here we used written verbs of pleasant, neutral, and unpleasant content as T1 items, while affectively neutral exemplars served as T2 and distractor events. The temporal distance between T1 and T2 was manipulated to contain either one distractor (intertarget interval 232 ms or five distractors (intertarget interval 696 ms. Students reported pleasant T1 words more accurately, compared to neutral and unpleasant words, indicating facilitation of appetitive content on performance during RSVP. Emotional relevance of T1 was at the expense of T2 accuracy: At an intertarget interval of 232 ms (i.e., during the AB period, identification of (neutral T2 words was impaired when preceded by pleasant and unpleasant T1s. No interference across targets was observed, however, beyond the blink period, in which T1 and T2 were separated by 696 ms. Thus, emotionally relevant events capture and hold attentional resources, at the cost of attentive processing in subsequent episodes. Contrary to our findings in adults, these capture effects were most obvious when the available capacity was limited, i.e., during the critical interval of the AB. The findings are discussed in light of the use of alternative cognitive strategies as development proceeds beyond early adolescence into adulthood.

  2. Distractor detection and suppression have a beneficial effect on attentional blink.

    Directory of Open Access Journals (Sweden)

    Jing Zhao

    Full Text Available BACKGROUND: Attentional blink (AB is a phenomenon that describes the difficulty individuals have in reporting the second of two masked targets if the second target (T2 arrives 200-500 ms after the first target (T1. Recent studies explain the AB from cognitive resources limitation to distractors interference. For example, the temporary loss of control (TLC hypothesis suggests that the AB is conduced by distractors disrupting the input filter for target processing. The inhibition models suggest that the T1+1 distractor triggers a suppression mechanism which could be beneficial for T1 processing but would suppress T2 at short T1-T2 lags. These models consider that the AB is caused by the appearance of distractors. However, in the present study, two methods were taken to help individuals to detect the distractors more effectively. An attenuated AB deficit was found when the distractors could be excluded or suppressed in time. We consider that under an appropriate condition the distractors detection and suppression have a beneficial effect on attentional blink. METHODOLOGY/PRINCIPAL FINDINGS: Two methods were employed to help individuals to detect the distractors more effectively: enlarging the low-level-physical characteristic difference between targets and distractors (Experiment 1 and restricting the sets of distractors (Experiment 2. Attenuated AB deficits were found as using the above manipulations. CONCLUSIONS/SIGNIFICANCE: The present study found when the distractors are detected or identified quickly, they could be effectively suppressed, in order to reduce the interference from the targets and result in a smaller AB deficit. We suggest that the suppression mechanism for distractors have a beneficial effect on AB.

  3. Modulation of trigeminal reflex excitability in migraine: effects of attention and habituation on the blink reflex.

    Science.gov (United States)

    de Tommaso, Marina; Murasecco, Donatella; Libro, Giuseppe; Guido, Marco; Sciruicchio, Vittorio; Specchio, Luigi Maria; Gallai, Virgilio; Puca, Francomichele

    2002-06-01

    The modulation of trigeminal reflex excitability in migraine patients was evaluated during the asymptomatic phase by studying the effects of attention, habituation and preconditioning stimulus on the R2 and R3 components of the blink reflex (BR). Fifty patients suffering from migraine without aura, 20 affected by migraine with aura and 35 sex- and age-matched controls were selected. In subgroups of migraine with-aura and without-aura patients, and normal controls, the blink reflex was elicited during different cognitive situations: (a) spontaneous mental activity; (b) stimulus anticipation; (c) recognition of target numbers. In the remaining subjects, R2 and R3 habituation was evaluated by repetitive stimulation at 1, 5, 10, 15, 20, 25 and 30 s intervals. The R2 and R3 recovery curves were also computed. A reduced R3 threshold with a normal pain threshold was found in migraine with-aura and without-aura patients; the R3 component was not significantly correlated with the pain thresholds in patients and controls. The R2 and R3 components were less influenced by the warning of the stimulus in migraine without-aura and migraine with-aura patients, in comparison with the control group. A slight increase of both R2 and R3 recovery after preconditioning stimulus was also observed in migraine patients, probably caused by a phenomenon of trigeminal hyperexcitability persisting after the last attack. The abnormal BR modulation by alerting expresses in migraine a dysfunction of adaptation capacity to environmental conditions, probably predisposing to migraine.

  4. Eating for Your Eyes

    Science.gov (United States)

    Stastny, Sherri Nordstrom; Garden-Robinson, Julie

    2011-01-01

    An educational program targeting older adults was developed to increase knowledge regarding nutrition and eye health. With age, the chance for eye disease increases, so prevention is critical. The Eating for Your Eyes program has promoted behavior changes regarding eye health among the participants. This program is easily replicated and use is…

  5. Eye Injuries (For Parents)

    Science.gov (United States)

    ... the eye nausea or vomiting after an eye injury Think Prevention! Kids who play sports should wear protective goggles or unbreakable glasses as needed. Keep chemicals and other potentially dangerous objects out of the reach of children. Reviewed by: Steven Dowshen, ... (Conjunctivitis) Eyes Corneal Abrasions Styes Activity: Eyes ...

  6. The Human Eye Position Control System in a Rehabilitation Setting

    Directory of Open Access Journals (Sweden)

    Yvonne Nolan

    2005-01-01

    Full Text Available Our work at Ireland’s National Rehabilitation Hospital involves designing communication systems for people suffering from profound physical disabilities. One such system uses the electro-oculogram, which is an (x,y system of voltages picked up by pairs of electrodes placed, respectively, above and below and on either side of the eyes. The eyeball has a dc polarisation between cornea and back, arising from the photoreceptor rods and cones in the retina. As the eye rotates, the varying voltages projected onto the electrodes drive a cursor over a mimic keyboard on a computer screen. Symbols are selected with a switching action derived, for example, from a blink. Experience in using this mode of communication has given us limited facilities to study the eye position control system. We present here a resulting new feedback model for rotation in either the vertical or the horizontal plane, which involves the eyeball controlled by an agonist-antagonist muscle pair, modelled by a single equivalent bidirectional muscle with torque falling off linearly with angular velocity. We have incorporated muscle spindles and have tuned them by pole assignment associated with an optimum stability criterion.

  7. Brain-computer interface combining eye saccade two-electrode EEG signals and voice cues to improve the maneuverability of wheelchair.

    Science.gov (United States)

    Wang, Ker-Jiun; Zhang, Lan; Luan, Bo; Tung, Hsiao-Wei; Liu, Quanfeng; Wei, Jiacheng; Sun, Mingui; Mao, Zhi-Hong

    2017-07-01

    Brain-computer interfaces (BCIs) largely augment human capabilities by translating brain wave signals into feasible commands to operate external devices. However, many issues face the development of BCIs such as the low classification accuracy of brain signals and the tedious human-learning procedures. To solve these problems, we propose to use signals associated with eye saccades and blinks to control a BCI interface. By extracting existing physiological eye signals, the user does not need to adapt his/her brain waves to the device. Furthermore, using saccade signals to control an external device frees the limbs to perform other tasks. In this research, we use two electrodes placed on top of the left and right ears of thirteen participants. Then we use Independent Component Analysis (ICA) to extract meaningful EEG signals associated with eye movements. A sliding-window technique was implemented to collect relevant features. Finally, we classified the features as horizontal or blink eye movements using KNN and SVM. We were able to achieve a mean classification accuracy of about 97%. The two electrodes were then integrated with off-the-shelf earbuds to control a wheelchair. The earbuds can generate voice cues to indicate when to rotate the eyeballs to certain locations (i.e., left or right) or blink, so that the user can select directional commands to drive the wheelchair. In addition, through properly designing the contents of voice menus, we can generate as many commands as possible, even though we only have limited numbers of states of the identified eye saccade movements.

  8. Temporal constraints on visual perception: A psychophysical investigation of the relation between attention capture and the attentional blink

    DEFF Research Database (Denmark)

    Nielsen, Simon

    While the richness of our visual perceptions is nearly boundless, the rate with which we can perceive information is limited. For instance when we are required to perceive two consecutive target objects following briefly after each other, the accuracy with which we can report the second target...... be triggered by attention capture to the first object (Folk, Leber & Egeth, 2008) and that if making the first target easier to perceive increase its saliency this may increase the attentional blink (Chua, 2005). This thesis examines the attention capture hypothesis with focus on empirical investigations...... and a theoretical review. Specifically this work presents studies in which first target contrast is varied in two different attentional blink paradigms, while potential influences from bottleneck effects are controlled. Publication 1 describes findings using the two-target paradigm (Duncan, Ward & Shapiro, 1994...

  9. Associative stimulation of the supraorbital nerve fails to induce timing-specific plasticity in the human blink reflex

    DEFF Research Database (Denmark)

    Zeuner, Kirsten E; Knutzen, Arne; Al-Ali, Asmaa;

    2010-01-01

    Associative high-frequency electrical stimulation (HFS) of the supraorbital nerve in five healthy individuals induced long-term potentiation (LTP)-like or depression (LTD)-like changes in the human blink reflex circuit according to the rules of spike timing-dependent plasticity (Mao and Evinger...... the orbicularis oculi muscles, HFS(LTP) induced excessive LTP-like associative plasticity relative to healthy controls, which was normalized after botulinum toxin (BTX) injections (Quartarone et al, 2006)....

  10. Nearly Blinking-Free, High-Purity Single-Photon Emission by Colloidal InP/ZnSe Quantum Dots.

    Science.gov (United States)

    Chandrasekaran, Vigneshwaran; Tessier, Mickaël D; Dupont, Dorian; Geiregat, Pieter; Hens, Zeger; Brainis, Edouard

    2017-10-11

    Colloidal core/shell InP/ZnSe quantum dots (QDs), recently produced using an improved synthesis method, have a great potential in life-science applications as well as in integrated quantum photonics and quantum information processing as single-photon emitters. Single-particle spectroscopy of 10 nm QDs with 3.2 nm cores reveals strong photon antibunching attributed to fast (70 ps) Auger recombination of multiple excitons. The QDs exhibit very good photostability under strong optical excitation. We demonstrate that the antibunching is preserved when the QDs are excited above the saturation intensity of the fundamental-exciton transition. This result paves the way toward their usage as high-purity on-demand single-photon emitters at room temperature. Unconventionally, despite the strong Auger blockade mechanism, InP/ZnSe QDs also display very little luminescence intermittency ("blinking"), with a simple on/off blinking pattern. The analysis of single-particle luminescence statistics places these InP/ZnSe QDs in the class of nearly blinking-free QDs, with emission stability comparable to state-of-the-art thick-shell and alloyed-interface CdSe/CdS, but with improved single-photon purity.

  11. Biomechanical modeling of eye trauma for different orbit anthropometries.

    Science.gov (United States)

    Weaver, Ashley A; Loftis, Kathryn L; Duma, Stefan M; Stitzel, Joel D

    2011-04-29

    In military, automotive, and sporting safety, there is concern over eye protection and the effects of facial anthropometry differences on risk of eye injury. The objective of this study is to investigate differences in orbital geometry and analyze their effect on eye impact injury. Clinical measurements of the orbital aperture, brow protrusion angle, eye protrusion, and the eye location within the orbit were used to develop a matrix of simulations. A finite element (FE) model of the orbit was developed from a computed tomography (CT) scan of an average male and transformed to model 27 different anthropometries. Impacts were modeled using an eye model incorporating lagrangian-eulerian fluid flow for the eye, representing a full eye for evaluation of omnidirectional impact and interaction with the orbit. Computational simulations of a Little League (CD25) baseball impact at 30.1m/s were conducted to assess the effect of orbit anthropometry on eye injury metrics. Parameters measured include stress and strain in the corneoscleral shell, internal dynamic eye pressure, and contact forces between the orbit, eye, and baseball. The location of peak stresses and strains was also assessed. Main effects and interaction effects identified in the statistical analysis illustrate the complex relationship between the anthropometric variation and eye response. The results of the study showed that the eye is more protected from impact with smaller orbital apertures, more brow protrusion, and less eye protrusion, provided that the orbital aperture is large enough to deter contact of the eye with the orbit.

  12. Eye formation in rotating convection

    Science.gov (United States)

    Oruba, L.; Davidson, P. A.; Dormy, E.

    2017-02-01

    We consider rotating convection in a shallow, cylindrical domain. We examine the conditions under which the resulting vortex develops an eye at its core; that is, a region where the poloidal flow reverses and the angular momentum is low. For simplicity, we restrict ourselves to steady, axisymmetric flows in a Boussinesq fluid. Our numerical experiments show that, in such systems, an eye forms as a passive response to the development of a so-called eyewall, a conical annulus of intense, negative azimuthal vorticity that can form near the axis and separates the eye from the primary vortex. We also observe that the vorticity in the eyewall comes from the lower boundary layer, and relies on the fact the poloidal flow strips negative vorticity out of the boundary layer and carries it up into the fluid above as it turns upward near the axis. This process is effective only if the Reynolds number is sufficiently high for the advection of vorticity to dominate over diffusion. Finally we observe that, in the vicinity of the eye and the eyewall, the buoyancy and Coriolis forces are negligible, and so although these forces are crucial to driving and shaping the primary vortex, they play no direct role in eye formation in a Boussinesq fluid.

  13. Eye Drop Tips

    Science.gov (United States)

    ... Involved News About Us Donate In This Section Eye Drop Tips en Español email Send this article ... the reach of children. Steps For Putting In Eye Drops: Start by tilting your head backward while ...

  14. What Is Dry Eye?

    Medline Plus

    Full Text Available ... information about eye health and preserving your vision. Privacy Policy Related New Dry Eye Treatment is a ... the Academy Financial Relationships with Industry Medical Disclaimer Privacy Policy Terms of Service For Advertisers For Media ...

  15. What Is Dry Eye?

    Medline Plus

    Full Text Available ... tissue covering the white of your eye and inside your eyelids. Normally, our eyes constantly make tears ... Multimedia Public & Patients: Contact Us About the Academy Jobs at the Academy Financial Relationships with Industry Medical ...

  16. What Is Dry Eye?

    Medline Plus

    Full Text Available ... Pediatric Ophthalmology Education Center Oculofacial Plastic Surgery Center Laser Surgery Education Center Redmond Ethics Center Global Ophthalmology Guide Eye ... What Is Dry Eye? Leer en Español: ¿Qué ...

  17. TUBERCULOSIS AND THE EYE

    African Journals Online (AJOL)

    Key words: Mycobacteria; Tuberculosis; Eye ... of tuberculous eye disease or ocular tuberculosis has also been raised. Ocular ... patients with ocular complaints, compiled in an area ..... tuberculomas are usually solitary and may measure up.

  18. About the Eye

    Medline Plus

    Full Text Available ... you see. Check out the diagrams below to learn about each part of your eye and what ... the optic nerve to the brain. Watch now! Learn how the different parts of your eye work ...

  19. About the Eye

    Medline Plus

    Full Text Available ... The Visual System Your Eyes’ Natural Defenses Eye Health and Safety First Aid ... Your eyes are made up of many different parts that work together to help you see. Check out the ...

  20. What Is Dry Eye?

    Medline Plus

    Full Text Available ... about eye health and preserving your vision. Privacy Policy Related New Dry Eye Treatment is a Tear- ... Academy Financial Relationships with Industry Medical Disclaimer Privacy Policy Terms of Service For Advertisers For Media Ophthalmology ...

  1. Preventing eye injuries

    Directory of Open Access Journals (Sweden)

    Daksha Patel

    2016-01-01

    Full Text Available The main challenge in developing a strategy to prevent eye injuries is that there are so many different causes and situations that can lead to eye injuries, each requiring a different approach.

  2. Common Eye Disorders

    Science.gov (United States)

    ... www.cdc.gov/emailupdates/">What's this? Submit Button Common Eye Disorders Recommend on Facebook Tweet Share Compartir ... macular degeneration, cataract, diabetic retinopathy, and glaucoma. Other common eye disorders include amblyopia and strabismus. For a ...

  3. Opaque Contact Lens For Tracking Motion Of Eye

    Science.gov (United States)

    Zografos, James L., II; Gibson, Charles R.

    1993-01-01

    Opaque contact lens facilitates measurements of movements of eye; particularly, torsional movements. Lens, marked with pair of indices at diameter of 0.5 mm, provides stable, high-contrast reference for measurements of angular position and velocity of eye by use of video-image-analysis techniques. Intended for use in experiments on response of eye to vestibular balance mechanism.

  4. The all seeing eye?

    NARCIS (Netherlands)

    Koenderink, Jan J.

    2014-01-01

    The All Seeing Eye? Did you know that you are probably a believer in the All Seeing Eye? The odds are that I’m right—why? Well, the bulk of mainstream vision literature blindly relies on the All Seeing Eye. It is written all over papers, albeit between the lines. Understandably so, for scientists re

  5. About the Eye

    Medline Plus

    Full Text Available ... other programs with respect to blinding eye diseases, visual disorders, mechanisms of visual function, preservation of sight, and the special health ... Eye Ask a Scientist Video Series Glossary The Visual System Your Eyes’ Natural Defenses Eye Health and ...

  6. What Is Dry Eye?

    Medline Plus

    Full Text Available ... Tips & Prevention News Ask an Ophthalmologist Patient Stories Español Eye Health / Eye Health A-Z Dry Eye ... when I sleep? Feb 10, 2016 Leer en Español: ¿Qué Es el Ojo Seco? Find an Ophthalmologist ...

  7. About the Eye

    Medline Plus

    Full Text Available ... other programs with respect to blinding eye diseases, visual disorders, mechanisms of visual function, preservation of sight, and the special health ... Eye Ask a Scientist Video Series Glossary The Visual System Your Eyes’ Natural Defenses Eye Health and ...

  8. The all seeing eye?

    NARCIS (Netherlands)

    Koenderink, Jan J.|info:eu-repo/dai/nl/070864543

    2014-01-01

    The All Seeing Eye? Did you know that you are probably a believer in the All Seeing Eye? The odds are that I’m right—why? Well, the bulk of mainstream vision literature blindly relies on the All Seeing Eye. It is written all over papers, albeit between the lines. Understandably so, for scientists

  9. The interplay of attention and consciousness in visual search, attentional blink and working memory consolidation.

    Science.gov (United States)

    Raffone, Antonino; Srinivasan, Narayanan; van Leeuwen, Cees

    2014-05-05

    Despite the acknowledged relationship between consciousness and attention, theories of the two have mostly been developed separately. Moreover, these theories have independently attempted to explain phenomena in which both are likely to interact, such as the attentional blink (AB) and working memory (WM) consolidation. Here, we make an effort to bridge the gap between, on the one hand, a theory of consciousness based on the notion of global workspace (GW) and, on the other, a synthesis of theories of visual attention. We offer a theory of attention and consciousness (TAC) that provides a unified neurocognitive account of several phenomena associated with visual search, AB and WM consolidation. TAC assumes multiple processing stages between early visual representation and conscious access, and extends the dynamics of the global neuronal workspace model to a visual attentional workspace (VAW). The VAW is controlled by executive routers, higher-order representations of executive operations in the GW, without the need for explicit saliency or priority maps. TAC leads to newly proposed mechanisms for illusory conjunctions, AB, inattentional blindness and WM capacity, and suggests neural correlates of phenomenal consciousness. Finally, the theory reconciles the all-or-none and graded perspectives on conscious representation.

  10. Time to see the bigger picture: Individual differences in the attentional blink.

    Science.gov (United States)

    Willems, Charlotte; Martens, Sander

    2016-10-01

    If two to-be-identified targets are presented in close temporal succession, identification for the second target is typically impaired. This attentional blink (AB) phenomenon has long been considered as a robust, universal cognitive limitation. However, more recent studies have demonstrated that AB task performance greatly differs between individuals, with some individuals even showing no AB in certain paradigms. Several studies have focused on these individual differences in an attempt to reveal the mechanism underlying the AB, but an overview of this approach is currently missing. Here, by reviewing studies regarding individual differences in AB task performance, we investigate how individual differences have contributed to our understanding of the AB. We show that the individual differences AB literature provides reliable indications that the AB is a multifaceted phenomenon that presumably arises from a combination of factors; individuals with higher levels of executive working memory (WM) functioning and broad attentional focus perform better in the AB paradigm than individuals with lower executive functioning of WM and narrow attentional focus. As it turns out, seeing the bigger picture certainly seems helpful for AB task performance.

  11. Mo' money, mo' problems: Monetary motivation can exacerbate the attentional blink.

    Science.gov (United States)

    Biggs, Adam T; Adamo, Stephen H; Mitroff, Stephen R

    2015-01-01

    The attentional blink (AB) is a compelling psychological phenomenon wherein observers are less likely to identify a second target (T2) when it appears approximately 200 ms after a first target (T1) in a rapidly presented stream of items. The present investigation examined how monetary motivation could impact the AB when participants were differentially motivated to identify T1 versus T2. Participants completed one of three conditions where the only difference across conditions was a motivational manipulation: a standard AB task (control condition), a motivated condition with T1 worth double the points of T2, or a motivated condition with T1 worth half the points of T2 (points in the motivated conditions were linked to a possible monetary bonus). Motivation had an expected influence on overall performance as both motivated conditions had higher overall T1 accuracy relative to the control condition. More specific to the question at hand, the AB was exacerbated (ie T2 performance was worse shortly after T1) when T1 was worth more than T2. This finding suggests that participants overallocated attentional resources to T1 processing at the expense of T2 processing, and it supports current theories of the AB.

  12. The more your mind wanders, the smaller your attentional blink: an individual differences study.

    Science.gov (United States)

    Thomson, David R; Ralph, Brandon C W; Besner, Derek; Smilek, Daniel

    2015-01-01

    The present studies investigate the hypothesis that individuals who frequently report experiencing episodes of mind wandering do so because they under-invest attentional/executive resources in the external environment. Here we examined whether self-reported instances of mind wandering predict the magnitude of the "attentional blink" (AB) in a rapid serial visual presentation (RSVP) task, since a prominent view is that the AB derives from an over-investment of attention in the information stream. Study 1 demonstrates that subjective reports of mind wandering in a sustained attention task have a negative predictive relation with respect to the magnitude of the AB measured in a subsequent RSVP task. In addition, using the Spontaneous and Deliberate Mind Wandering Questionnaire in Study 2, we were again able to show that trait-level mind wandering in everyday life negatively predicts AB magnitude. We suggest that mind wandering may be the behavioural outcome of an adaptive cognitive style intended to maximize the efficient processing of dynamic and temporally unpredictable events.

  13. An investigation into the temporal dimension of the Mozart effect: evidence from the attentional blink task.

    Science.gov (United States)

    Ho, Cristy; Mason, Oliver; Spence, Charles

    2007-05-01

    In the present study, we examined whether the 'Mozart effect' would influence participants' temporal attention using a visual attentional blink (AB) task that provides a reliable measure of the temporal dynamics of visual attention. The 'Mozart effect' refers to the specific claim that listening to Mozart's Sonata for Two Pianos in D Major, K.448 can improve the performance in spatio-temporal tasks. Participants had to try and identify two target digits (in their correct order of presentation) presented amongst a stream of distractor letters in three different conditions (presented in separate blocks of trials): while listening to the Mozart sonata played normally, while listening to the same Mozart sonata played in reverse, and while in silence. The results showed that the participants were able to detect the second target (T2) significantly more accurately (given the correct detection of the first target, T1) in the AB stream when the Mozart sonata was played normally than in either of the other two conditions. Possible explanations for the differential effects of Mozart's music being played normally and in reverse and potential confounds in previous studies reporting a facilitatory 'Mozart effect' are discussed. Our results therefore provide the first empirical demonstration supporting the existence of a purely temporal component to the 'Mozart effect' using a non-spatial visual AB task.

  14. Drug release from liposome coated hydrogels for soft contact lenses: the blinking and temperature effect.

    Science.gov (United States)

    Paradiso, P; Colaço, R; Mata, J L G; Krastev, R; Saramago, B; Serro, A P

    2016-05-18

    In this article, liposome-based coatings aiming to control drug release from therapeutic soft contact lenses (SCLs) materials are analyzed. A PHEMA based hydrogel material loaded with levofloxacin is used as model system for this research. The coatings are formed by polyelectrolyte layers containing liposomes of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and DMPC + cholesterol (DMPC + CHOL). The effect of friction and temperature on the drug release is investigated. The aim of the friction tests is to simulate the blinking of the eyelid in order to verify if the SCLs materials coated with liposomes are able to keep their properties, in particular the drug release ability. It was observed that under the study conditions, friction did not affect significantly the drug release from the liposome coated PHEMA material. In contrast, increasing the temperature of release leads to an increase of the drug diffusion rate through the hydrogel. This phenomenon is recorded both in the control and in the coated samples. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2016.

  15. Medicare Benefits and Your Eyes

    Science.gov (United States)

    ... Subscribe to eNews Close Donate Medicare Benefits & Your Eyes Eye Health is Important! As you age, your risk ... that you need. Ask about eye exams! Routine Eye Exams Medicare does not generally cover the costs ...

  16. Prevent Eye Injuries from Fireworks

    Science.gov (United States)

    ... Financial Assistance Information Vision Screening and Eye Exams Zika Virus and Vision Eye Problems Eye Problems Amblyopia ( ... Eye Health Report Reports and External Resources The Cost of Vision Problems The Future of Vision Vision ...

  17. Differences of accommodative responses between two eyes under binocular viewing condition mediated by polarizing glasses%偏光镜介导的双眼注视状态下调节反应差异性研究

    Institute of Scientific and Technical Information of China (English)

    王瑞卿; 张妍; 胡娱新; 何宇茜; 纪冬梅; 王淑荣

    2016-01-01

    目的::探讨利用偏振效应构建的3种不同注视方式下双眼调节反应的差异。方法:前瞻性对照研究。选取15名正视眼志愿者入选本试验(年龄18~38岁,男6名,女9名)。利用偏光镜和液晶显示器的偏振特性,设置3种不同的注视方式:(1)右眼能看到屏幕显示的视标,左眼无法看到;(2)右眼无法看到屏幕视标,左眼能看到;(3)双眼均能看到屏幕视标。使用红外电脑验光仪分别测量注视距离为5、2、1、0.5、0.33m时的客观验光值(以等效球镜计算),计算所有受试者在以上3种注视方式下的调节反应量。采用重复测量的方差分析和t检验比较不同注视方式下双眼调节反应的差异。结果:采用注视方式(1)(2)时,双眼在各种调节刺激下产生的调节反应有明显差异,其中使用眼(能看到屏幕视标眼)的调节反应均比未使用眼(不能看到屏幕视标眼)大(P0.05)。结论:双眼开放状态下,经常被使用眼的睫状肌处于相对紧张状态,较少使用眼则处于相对放松状态。这种调节反应的不均衡性,很可能是促发近视发生的危险因素。%AlM: To study the differences of accommodative responses between the two eyes under 3 different polarized viewing conditions.METHODS:Fifteen volunteers with emmetrope were recruited into this study ( aged 18 ~ 38 ) , 6 males and 9 females. Three different viewing conditions were set up by using polarizing glasses and liquid crystal display:(1) right eye could see the visual target on the screen, but left eye cannot see it;( 2 ) left eye could see the visual target on the screen, but right eye cannot see it;(3)both eyes could see the target. Accommodative responses were measured by infrared auto-refractor when fixating at the target at 5, 2, 1, 0. 5 and 0. 33m under the above 3 viewing conditions. The differences of accommodative responses under different viewing conditions were compared by using

  18. Legibility difference between e-books and paper books by using an eye tracker.

    Science.gov (United States)

    Kim, Jung-Yong; Min, Seung-Nam; Subramaniyam, Murali; Cho, Young-Jin

    2014-01-01

    The aim of the study was to evaluate the difference in legibility between e-books and paper books by using an eye tracker. Eight male and eight female subjects free of eye disease participated in the experiment. The experiment was conducted using a 2 × 3 within-subject design. The book type (e-book, paper book) and font size (8 pt, 10 pt, 12 pt) were independent variables, and fixation duration time, saccade length, blink rate and subjective discomfort were dependent variables. In the results, all dependent variables showed that reading paper books provided a better experience than reading e-books did. These results indicate that the legibility of e-books needs further improvement, considering fixation duration time, saccade movement, eye fatigue, device and so on. This study evaluated the legibility difference between e-books and paper books from the viewpoint of readability, eye fatigue and subjective discomfort by using an eye tracker. The results showed that paper books provided a better experience than e-books. This indicates that the readability of e-books needs further improvement in relation to paper books.

  19. Application of eye-tracking in the testing of drivers: A review of research.

    Science.gov (United States)

    Kapitaniak, Bronisław; Walczak, Marta; Kosobudzki, Marcin; Jóźwiak, Zbigniew; Bortkiewicz, Alicja

    2015-01-01

    Recording and analyzing eye movements provide important elements for understanding the nature of the task of driving a vehicle. This article reviews the literature on eye movement strategies employed by drivers of vehicles (vehicle control, evaluation of the situation by analyzing essential visual elements, navigation). Special focus was placed on the phenomenon of conspicuity, the probability of perceiving an object in the visual field and the factors that determine it. The article reports the methods of oculographic examination, with special emphasis on the non-invasive technique using corneal reflections, and the criteria for optimal selection of the test apparatus for drivers in experimental conditions (on a driving simulator) and in real conditions. Particular attention was also paid to the helmet - or glass-type devices provided with 1 or 2 high definition (HD) camcorders recording the field of vision and the direction of gaze, and the non-contact devices comprising 2 or 3 cameras and an infrared source to record eye and head movements, pupil diameter, eye convergence distance, duration and frequency of eyelid blinking. A review of the studies conducted using driver eye-tracking procedure was presented. The results, in addition to their cognitive value, can be used with success to optimize the strategy of drivers training. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

  20. EYE GAZE TRACKING

    DEFF Research Database (Denmark)

    2017-01-01

    This invention relates to a method of performing eye gaze tracking of at least one eye of a user, by determining the position of the center of the eye, said method comprising the steps of: detecting the position of at least three reflections on said eye, transforming said positions to spanning...... a normalized coordinate system spanning a frame of reference, wherein said transformation is performed based on a bilinear transformation or a non linear transformation e.g. a möbius transformation or a homographic transformation, detecting the position of said center of the eye relative to the position...... of said reflections and transforming this position to said normalized coordinate system, tracking the eye gaze by tracking the movement of said eye in said normalized coordinate system. Thereby calibration of a camera, such as knowledge of the exact position and zoom level of the camera, is avoided...

  1. Diagnosis of dry eye disease and emerging technologies

    Science.gov (United States)

    Zeev, Maya Salomon-Ben; Miller, Darby Douglas; Latkany, Robert

    2014-01-01

    Dry eye is one of the most commonly encountered problems in ophthalmology. Signs can include punctate epithelial erosions, hyperemia, low tear lakes, rapid tear break-up time, and meibomian gland disease. Current methods of diagnosis include a slit-lamp examination with and without different stains, including fluorescein, rose bengal, and lissamine green. Other methods are the Schirmer test, tear function index, tear break-up time, and functional visual acuity. Emerging technologies include meniscometry, optical coherence tomography, tear film stability analysis, interferometry, tear osmolarity, the tear film normalization test, ocular surface thermography, and tear biomarkers. Patient-specific considerations involve relevant history of autoimmune disease, refractive surgery or use of oral medications, and allergies or rosacea. Other patient considerations include clinical examination for lid margin disease and presence of lagophthalmos or blink abnormalities. Given a complex presentation and a variety of signs and symptoms, it would be beneficial if there was an inexpensive, readily available, and reproducible diagnostic test for dry eye. PMID:24672224

  2. A case with a rare type of trigemino-oculomotor synkinesis: clinical and blink reflex study.

    Science.gov (United States)

    Balaban, H; Yildiz, O K; Eliaçik, S; Bolayir, E; Topaktaş, S

    2010-12-01

    Several abnormal synkinetic eye movements during jaw movements may often be seen after trauma or congenitally in the Marcus Gunn jaw winking phenomenon. The most frequent type consists of unilateral ptosis and retraction of the ptotic lid upon moving the jaw. The authors describe a case with isolated simultaneous adduction of the left eye upon jaw movement. This paper presents a rare case of Marcus Gunn jaw winking with trigemino-oculomotor synkinesis.

  3. 'Goats that stare at men'--revisited: do dwarf goats alter their behaviour in response to eye visibility and head direction of a human?

    Science.gov (United States)

    Nawroth, Christian; von Borell, Eberhard; Langbein, Jan

    2016-05-01

    Being able to recognise when one is being observed by someone else is thought to be adaptive during cooperative or competitive events. In particular for prey species, this ability should be of use in the context of predation. A previous study reported that goats (Capra aegagrus hircus) alter their behaviour according to the body and head orientation of a human experimenter. During a food anticipation task, an experimenter remained in a particular posture for 30 s before delivering a reward, and the goats' active anticipation and standing alert behaviour were analysed. To further evaluate the specific mechanisms at work, we here present two additional test conditions. In particular, we investigated the effects of the eye visibility and head orientation of a human experimenter on the behaviour of the goats (N = 7). We found that the level of the subjects' active anticipatory behaviour was highest in the conditions where the experimenter was directing his head and body towards the goat ('Control' and 'Eyes closed' conditions), but the anticipatory behaviour was significantly decreased when the body ('Head only') or the head and body of the experimenter were directed away from the subject ('Back' condition). For standing alert, we found no significant differences between the three conditions in which the experimenter was directing his head towards the subject ('Control', 'Eyes closed' and 'Head only'). This lack of differences in the expression of standing alert suggests that goats evaluate the direction of a human's head as an important cue in their anticipatory behaviour. However, goats did not respond to the visibility of the experimenter's eyes alone.

  4. Analyzing blinking effects in super resolution localization microscopy with single-photon SPAD imagers

    Science.gov (United States)

    Antolovic, Ivan Michel; Burri, Samuel; Bruschini, Claudio; Hoebe, Ron; Charbon, Edoardo

    2016-02-01

    For many scientific applications, electron multiplying charge coupled devices (EMCCDs) have been the sensor of choice because of their high quantum efficiency and built-in electron amplification. Lately, many researchers introduced scientific complementary metal-oxide semiconductor (sCMOS) imagers in their instrumentation, so as to take advantage of faster readout and the absence of excess noise. Alternatively, single-photon avalanche diode (SPAD) imagers can provide even faster frame rates and zero readout noise. SwissSPAD is a 1-bit 512×128 SPAD imager, one of the largest of its kind, featuring a frame duration of 6.4 μs. Additionally, a gating mechanism enables photosensitive windows as short as 5 ns with a skew better than 150 ps across the entire array. The SwissSPAD photon detection efficiency (PDE) uniformity is very high, thanks on one side to a photon-to-digital conversion and on the other to a reduced fraction of "hot pixels" or "screamers", which would pollute the image with noise. A low native fill factor was recovered to a large extent using a microlens array, leading to a maximum PDE increase of 12×. This enabled us to detect single fluorophores, as required by ground state depletion followed by individual molecule return imaging microscopy (GSDIM). We show the first super resolution results obtained with a SPAD imager, with an estimated localization uncertainty of 30 nm and resolution of 100 nm. The high time resolution of 6.4 μs can be utilized to explore the dye's photophysics or for dye optimization. We also present the methodology for the blinking analysis on experimental data.

  5. Magnetic tracking of eye position in freely behaving chickens

    Directory of Open Access Journals (Sweden)

    Jason S Schwarz

    2013-11-01

    Full Text Available Research on the visual system of non-primates, such as birds and rodents, is increasing. Evidence that neural responses can differ dramatically between head-immobilized and freely behaving animals underlines the importance of studying visual processing in ethologically relevant contexts. In order to systematically study visual responses in freely behaving animals, an unobtrusive system for monitoring eye-in-orbit position in real time is essential. We describe a novel system for monitoring eye position that utilizes a head-mounted magnetic displacement sensor coupled with an eye-implanted magnet. This system is small, lightweight, and offers high temporal and spatial resolution in real time. We use the system to demonstrate the stability of the eye and the stereotypy of eye position during two different behavioral tasks in chickens. This approach offers a viable alternative to search coil and optical eye tracking techniques for high resolution tracking of eye-in-orbit positions in behaving animals.

  6. Perceptual and not physical eye contact elicits pupillary dilation.

    Science.gov (United States)

    Honma, Motoyasu; Tanaka, Yasuto; Osada, Yoshihisa; Kuriyama, Kenichi

    2012-01-01

    Eye contact is important to share communication during social interactions. However, how accurately humans can perceive the gaze direction of others toward themselves and whether pupils dilate when humans consciously or unconsciously perceive own eyes are looked by others remain unclear. In this study, we examined the relationship between the explicit perception of looking into each other's eyes and the implicit physiological response of pupillary dilation by using an original face-to-face method. We found that humans do not correctly detect the gaze direction of others. Furthermore, one's pupils dilated when one gazed at others' eyes. Awareness of others' gaze on one's eyes, rather than the actual focusing of other's gaze on one's eyes, enhanced pupillary dilation. Therefore, physiological responses are caused not when people actually look into each other's gaze, but when the consciousness of other's gaze is activated, which suggests that eye contact often involves one-way communication.

  7. Magnetic tracking of eye position in freely behaving chickens

    Science.gov (United States)

    Schwarz, Jason S.; Sridharan, Devarajan; Knudsen, Eric I.

    2013-01-01

    Research on the visual system of non-primates, such as birds and rodents, is increasing. Evidence that neural responses can differ dramatically between head-immobilized and freely behaving animals underlines the importance of studying visual processing in ethologically relevant contexts. In order to systematically study visual responses in freely behaving animals, an unobtrusive system for monitoring eye-in-orbit position in real time is essential. We describe a novel system for monitoring eye position that utilizes a head-mounted magnetic displacement sensor coupled with an eye-implanted magnet. This system is small, lightweight, and offers high temporal and spatial resolution in real time. We use the system to demonstrate the stability of the eye and the stereotypy of eye position during two different behavioral tasks in chickens. This approach offers a viable alternative to search coil and optical eye tracking techniques for high resolution tracking of eye-in-orbit position in behaving animals. PMID:24312023

  8. Teamwork for eye care

    Directory of Open Access Journals (Sweden)

    M Babar Qureshi

    2014-04-01

    Full Text Available Human resource development (HRD – the development of the people who deliver health care – has been identified as one of the key pillars of eye health delivery. HRD is one of the essential building blocks of the World Health Organization (WHO Global Action Plan: ‘Towards universal eye health’. The importance of HRD is also recognised beyond eye care, as can be seen in the WHO Health Systems approach.

  9. Personal Identification by Eyes

    OpenAIRE

    Marinović, Dunja; Čoklo, Miran; Njirić, Sanja; Mužić, Vedrana

    2011-01-01

    Identification of persons through the eyes is in the field of biometrical science. Many security systems are based on biometric methods of personal identification, to determine whether a person is presenting itself truly. The human eye contains an extremely large number of individual characteristics that make it particularly suitable for the process of identifying a person. Today, the eye is considered to be one of the most reliable body parts for human identification. Systems usi...

  10. Infrared Eye: Prototype 2

    Science.gov (United States)

    2016-06-07

    within the wide field and slaved to the operator’s line of sight by means of an eye- tracking system. The images from both cameras are fused and shown...simultaneously on a high resolution CRT display unit, interfaced with the eye- tracking unit in order to optimize the human-machine interface. The IR Eye...system was flight tested using the Advanced system Research Aircraft (Bell 412 helicopter) from the Flight Research Laboratory of the National Research

  11. What Is Dry Eye?

    Medline Plus

    Full Text Available ... Academy Publications EyeNet Ophthalmology Ophthalmology Retina Information for: International Ophthalmologists Media Medical Students Patients and Public Technicians and Nurses Senior Ophthalmologists ...

  12. What Is Dry Eye?

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    Full Text Available ... Ophthalmology Education Center Oculofacial Plastic Surgery Center Laser Surgery Education Center Redmond Ethics ... Services Advocacy Foundation About Subspecialties & More Eye ...

  13. Two blinking mechanisms in highly confined AgInS2 and AgInS2/ZnS quantum dots evaluated by single particle spectroscopy

    Science.gov (United States)

    Cichy, B.; Rich, R.; Olejniczak, A.; Gryczynski, Z.; Strek, W.

    2016-02-01

    Ternary AgInS2 quantum dots (QDs) have been found as promising cadmium-free, red-shifted, and tunable luminescent bio-probes with efficient Stokes and anti-Stokes excitations and luminescence lifetimes (ca. 100 ns) convenient for time resolved techniques like fluorescence life-time imaging. Although the spectral properties of the AgInS2 QDs are encouraging, the complex recombination kinetics in the QDs being still far from understood, limits their full utility. In this paper we report on a model describing the recombination pathways responsible for large deviations from the first-order decay law observed commonly in the ternary chalcogenides. The presented results were evaluated by means of individual AgInS2 QD spectroscopy aided by first principles calculations including the electronic structure and structural reconstruction of the QDs. Special attention was devoted to study the impact of the surface charge state on the excited state relaxation and effect of its passivation by Zn2+ ion alloying. Two different blinking mechanisms related to defect-assisted charge imbalance in the QD responsible for fast non-radiative relaxation of the excited states as well as surface recharging of the QD were found as the major causes of deviations from the first-order decay law. Careful optimization of the AgInS2 QDs would help to fabricate new red-shifted and tunable fluorescent bio-probes characterized by low-toxicity, high quantum yield, long luminescence lifetime, and time stability, leading to many novel in vitro and in vivo applications based on fluorescence lifetime imaging (FLIM) and time-gated detection.Ternary AgInS2 quantum dots (QDs) have been found as promising cadmium-free, red-shifted, and tunable luminescent bio-probes with efficient Stokes and anti-Stokes excitations and luminescence lifetimes (ca. 100 ns) convenient for time resolved techniques like fluorescence life-time imaging. Although the spectral properties of the AgInS2 QDs are encouraging, the complex

  14. Eye lrritation caused by Formaldehyde as an Indoor AIr Pollution—A Controlled Human Exposure Experiment

    Institute of Scientific and Technical Information of China (English)

    YANGXU; ZHANGYUN-PING; 等

    2001-01-01

    The present study focuses on health assessment of wood based panels which are widely used in interior decoration practices over the recent years in China.Formaldehyde has been i-dentified as chemical indicator of (IAO) and an indoor air pollutant.To test its health effects experiment was undertaken.Method: A small environmental test chamber(60/L) was used as the genertor of emission gas from new panels,and was operating at a temperature of 22.7±0.6℃ and a humidity of 44.4±2.5% with an air exchange rate of 1.0±0.15h-1.On the three experimental days the values of product lodaing in chamber were 4,2 and 6m2/m3,respectively,Eight people were selected randomly from the students and employees of Wuhan Health and Anti-epidemic Station as subjects,with an average age of 21.9±5.9 years,and a gender ratio of 1:1,and two of them were smokders(one male and one female).The subjects' eyes were exposed to formaldehyde through a pair of googles.Each goggle had its flow inlet and outlet,and connected to chamber exhaust of emission gas and to an exhaust from the room.The exposure time was very short,just 5 minutes and the formaldehyde doses were at 1.65±0.01,2.99±0.07and 4.31±0.02ppm,A6-mm linear visual analogue rating scales was used to measure the intensity of sensory eye irritation and a video tape racorder was used to record eye blinking frequency.Results:the results demonstrated that tests of sensory eye irritation and eye blinking can be used for materials testing,and that a dose-effect as well as a time-variance of the effect can be measured.Conclusion:The tests showed that eye irritation was perceived at all of the three levels.±

  15. Eye proprioception may provide real time eye position information.

    Science.gov (United States)

    Wang, Jing; Pan, Yujun

    2013-03-01

    Because of the frequency of eye movements, online knowledge of eye position is crucial for the accurate spatial perception and behavioral navigation. Both the internal monitoring signal (corollary discharge) of eye movements and the eye proprioception signal are thought to contribute to the localization of the eye position in the orbit. However, the functional role of these two eye position signals in spatial cognition has been disputed for more than a century. The predominant view proposes that the online analysis of eye position is exclusively provided by the corollary discharge signal, while the eye proprioception signal only plays a role in the long-term calibration of the oculomotor system. However, increasing evidence from recent behavioral and physiological studies suggests that the eye proprioception signal may play a role in the online monitoring of eye position. The purpose of this review is to discuss the feasibility and possible function of the eye proprioceptive signal for online monitoring of eye position.

  16. Three-dimensional multimodal sub-diffraction imaging with spinning-disk confocal microscopy using blinking/ fluctuating probes

    Institute of Scientific and Technical Information of China (English)

    Xuanze Chen[2; Zhiping zeng[2; Hening Wang[1; Peng Xi[1

    2015-01-01

    Three-dimensional imaging cannot be achieved easily using previously developed localization super-resolution techniques. Here, we present a three-dimensional multimodal sub-diffraction imaging technique with spinning-disk (SD) confocal microscopy called 3D-MUSIC, which not only has all the advantages of SD confocal microscopy such as fast imaging speed, high signal-to-noise ratio, and optical-sectioning capability, but also extends its spatial resolution limit along all three dimensions. Both axial and lateral resolution can be improved simul- taneously by virtue of the blinking/fluctuating nature of modified fluorescent probes, exemplified with the quantum dots. Further, super-resolution images with dual modality can be obtained through super-resolution optical fluctuation imaging (SOFI) and bleaching/blinking-assisted localization microscopy (BALM). Therefore, fast super-resolution imaging can be achieved with SD-SOFI by capturing only 100 frames while SD-BaLM yields high-resolution imaging.

  17. Excessive blinking and ataxia in a child with occult neuroblastoma and voltage-gated potassium channel antibodies.

    LENUS (Irish Health Repository)

    Allen, Nicholas M

    2012-05-01

    A previously healthy 9-year-old girl presented with a 10-day history of slowly progressive unsteadiness, slurred speech, and behavior change. On examination there was cerebellar ataxia and dysarthria, excessive blinking, subtle perioral myoclonus, and labile mood. The finding of oligoclonal bands in the cerebrospinal fluid prompted paraneoplastic serological evaluation and search for an occult neural crest tumor. Antineuronal nuclear autoantibody type 1 (anti-Hu) and voltage-gated potassium channel complex antibodies were detected in serum. Metaiodobenzylguanidine scan and computed tomography scan of the abdomen showed a localized abdominal mass in the region of the porta hepatis. A diagnosis of occult neuroblastoma was made. Resection of the stage 1 neuroblastoma and treatment with pulsed corticosteroids resulted in resolution of all symptoms and signs. Excessive blinking has rarely been described with neuroblastoma, and, when it is not an isolated finding, it may be a useful clue to this paraneoplastic syndrome. Although voltage-gated potassium channel complex autoimmunity has not been described previously in the setting of neuroblastoma, it is associated with a spectrum of paraneoplastic neurologic manifestations in adults, including peripheral nerve hyperexcitability disorders.

  18. What Is Dry Eye?

    Medline Plus

    Full Text Available ... Registry Medicare Physician Payment Meetings and Deadlines Ophthalmology Job Center Our Sites EyeWiki International Society of Refractive ... Registry Medicare Physician Payment Meetings and Deadlines Ophthalmology Job Center Our Sites EyeWiki International Society of Refractive ...

  19. What Is Dry Eye?

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    Full Text Available ... Deadlines Ophthalmology Job Center Our Sites EyeWiki International Society of Refractive Surgery Museum of Vision Subspecialties Cataract/ ... Deadlines Ophthalmology Job Center Our Sites EyeWiki International Society of Refractive Surgery Museum of Vision Subspecialties Cataract/ ...

  20. About the Eye

    Medline Plus

    Full Text Available ... NIH), the National Eye Institute’s mission is to “conduct and support research, training, health information dissemination, and other programs with respect to blinding eye diseases, visual disorders, mechanisms of visual function, preservation of sight, and the ...

  1. What Is Dry Eye?

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    Full Text Available ... Emergency Relief EyeCare America Help IRIS Registry Medicare Physician Payment Meetings and Deadlines Ophthalmology Job Center Our ... Emergency Relief EyeCare America Help IRIS Registry Medicare Physician Payment Meetings and Deadlines Ophthalmology Job Center Our ...

  2. About the Eye

    Medline Plus

    Full Text Available ... Optical Illusions Printables About the Eye Your eyes are made up of many different parts that work ... Media Information in Spanish (Información en español) Website, ... Office of Science Communications, Public Liaison, and Education. Technical questions about ...

  3. Eye-Tracking

    Directory of Open Access Journals (Sweden)

    Gabriela GROSSECK

    2006-01-01

    Full Text Available Eye-tracking: one of the newest and most efficient methods of improving on-line marketing communication is called eye-tracking. Marketers have borrowed this technique, usually used in psychological and medical research, in order to study web users with the help of a video camera incorporated in the monitor.

  4. Perception of eye positions

    NARCIS (Netherlands)

    Lorteije, J.A.M.; Wezel, R.J.A. van; Lankheet, M.J.M.

    2002-01-01

    In a two-alternative forced-choice psychophysical test human subjects were tested for their ability to perceive their own viewing direction. A small red flash was presented at different horizontal positions left or right from the subjects' eye position on the screen. Eye positions were recorded with

  5. Understanding pink eye

    Science.gov (United States)

    Pink eye (PE) is a physiological tuber disorder that can result in serious processing complications and storage losses. The earliest external symptoms consist of an ephemeral pinkish discoloration around tuber eyes, predominately at the bud end of the tuber. These pinkish areas can then develop into...

  6. Photorefraction of the Eye

    Science.gov (United States)

    Colicchia, Giuseppe; Wiesner, Hartmut; Zollman, Dean

    2015-01-01

    Photorefraction is a method to easily estimate the refractive state of the eye. The principle of photorefraction involves projecting light into the eye during flash photography and then examining the paths of light that emerge from the pupil after scattering on the back portion of the interior of the eyeball (fundus). We will explain the optical…

  7. Eye tracking social preferences

    NARCIS (Netherlands)

    Jiang, Ting; Potters, Jan; Funaki, Yukihiko

    We hypothesize that if people are motivated by a particular social preference, then choosing in accordance with this preference will lead to an identifiable pattern of eye movements. We track eye movements while subjects make choices in simple three-person distribution experiments. We characterize

  8. BullsEye

    DEFF Research Database (Denmark)

    Klokmose, Clemens Nylandsted; Kristensen, Janus Bager; Bagge, Rolf

    2014-01-01

    implemented primarily in shaders on the GPU. The techniques are realized in the BullsEye computer vision software. We demonstrate experimentally that BullsEye provides sub-pixel accuracy down to a tenth of a pixel, which is a significant improvement compared to the commonly used reacTIVision software....

  9. Is performance on probed serial recall tasks in schizophrenia related to duration of Attentional Blink?

    Directory of Open Access Journals (Sweden)

    David P. McAllindon

    2017-03-01

    Full Text Available Schizophrenia is associated with a deficit in working memory, with the degree of working memory impairment related to the level of social and occupational functioning. This study tests the hypothesis that the working memory deficits in individuals with schizophrenia can be explained by slow processing of visual stimuli, as measured by the attentional blink (AB task. Individuals with schizophrenia (SC and controls (HC were recruited from an early intervention service for psychosis and the local community. Data from 16 SC (11M/5F, mean = 26.4 yo and 20 age-matched HC (11M/9F, mean = 25.8 yo were analyzed. Each subject performed an AB task to determine their AB duration, defined as the lag to reach their plateau performance (ltpp. As expected, mean AB duration in the SC group (575 ms was significantly slower than HC (460 ms; p = 0.007. Recall accuracy of the SC group on a working memory task, a 6-item probed serial recall task (PSR, was reduced compared to the HC group at a standard interstimulus interval (ISI (p = 0.002. When the individual's AB duration was then used to adjust the ISI on the PSR task to three relative ISI rates (Slow (2 × ltpp, Medium (ltpp and Fast (1/2 × ltpp, performance on the PSR task was affected by group, position and ISI and qualified by an ISI ∗ position (p = 0.001 and a trend to a triple interaction (p = 0.054. There was main effect of group at all ISIs, but group ∗ position interaction only at Slow ISI (p = 0.01. Our interpretation of the results is that absolute ISI, rather than ISI relative to AB duration, affected performance.

  10. Word frequency and the attentional blink: the effects of target difficulty on retrieval and consolidation processes.

    Directory of Open Access Journals (Sweden)

    Stefan M Wierda

    Full Text Available BACKGROUND: When a second target (T2 is presented in close succession of a first target (T1 within a stream of non-targets, people often fail to detect T2-a deficit known as the attentional blink (AB. Two types of theories can be distinguished that have tried to account for this phenomenon. Whereas attentional-control theories suggest that protection of consolidation processes induces the AB, limited-resource theories claim that the AB is caused by a lack of resources. According to the latter type of theories, increasing difficulty of one or both targets should increase the magnitude of the AB. Similarly, attentional-control theories predict that a difficult T1 increases the AB due to prolonged processing. However, the prediction for T2 is not as straightforward. Prolonged processing of T2 could cause conflicts and increase the AB. However, if consolidation of T2 is postponed without loss of identity, the AB might be attenuated. METHODOLOGY/PRINCIPAL FINDINGS: Participants performed an AB task that consisted of a stream of distractor non-words and two target words. Difficulty of T1 and T2 was manipulated by varying word-frequency. Overall performance for high-frequency words was better than for low-frequency words. When T1 was highly frequent, the AB was reduced. The opposite effect was found for T2. When T2 was highly frequent, performance during the AB period was relatively worse than for a low-frequency T2. A threaded-cognition model of the AB was presented that simulated the observed pattern of behavior by taking changes in the time-course of retrieval and consolidation processes into account. Our results were replicated in a subsequent ERP study. CONCLUSIONS/SIGNIFICANCE: The finding that a difficult low-frequency T2 reduces the magnitude of the AB is at odds with limited-resource accounts of the AB. However, it was successfully accounted for by the threaded-cognition model, thus providing an explanation in terms of attentional control.

  11. The Eyes as Windows Into Other Minds.

    Science.gov (United States)

    Grossmann, Tobias

    2017-01-01

    Eyes have been shown to play a key role during human social interactions. However, to date, no comprehensive cross-discipline model has provided a framework that can account for uniquely human responses to eye cues. In this review, I present a framework that brings together work on the phylogenetic, ontogenetic, and neural bases of perceiving and responding to eyes. Specifically, I argue for a two-process model: a first process that ensures privileged attention to information encoded in the eyes and is important for the detection of other minds and a second process that permits the decoding of information contained in the eyes concerning another person's emotional and mental states. To some degree, these processes are unique to humans, emerge during different times in infant development, can be mapped onto distinct but interconnected brain regions, and likely serve critical functions in facilitating cooperative interactions in humans. I also present evidence to show that oxytocin is a key modulator of sensitive responding to eye cues. Viewing eyes as windows into other minds can therefore be considered a hallmark feature of human social functioning deeply rooted in our biology.

  12. Herpes zoster eye complications: rates and trends.

    Science.gov (United States)

    Yawn, Barbara P; Wollan, Peter C; St Sauver, Jennifer L; Butterfield, Linda C

    2013-06-01

    To provide population-based data on the risk, types, and outcomes of eye involvement in herpes zoster (HZ). A cohort study based on review of the medical records of patients in whom HZ was diagnosed between January 1, 1980, and December 31, 2007, was performed. Herpes zoster was confirmed by the presence of the typical rash and symptoms or by laboratory testing, and eye involvement was confirmed by ophthalmologists' evaluation. Information was collected on all eye diagnoses and on HZ eye-related visits, treatments, procedures, and outcomes. Of the 7370 individuals with HZ in any dermatome, 184 (2.5%) had eye involvement. The mean age of the 184 was 62.6 years, and 5 cases occurred in patients younger than 21. Overall, 6.5% (12) were immunosuppressed at the time of the eye complications. The rate of increase in HZ eye involvement was 23% by decade from 1980 to 2007. Common eye complications were keratitis (n=144, 76.2%), uveitis/iritis (n=88, 46.6%), and conjunctivitis (n=67, 35.4%). Recurrent keratitis and recurrent iritis/uveitis occurred in 6.9% (13) and 7.4% (14), respectively. Outcomes included 6 patients (3.3%) with new vision decrements to 20/200 or worse. Two individuals had successful corneal transplants. Another 6 individuals (3.3%) had lid ptosis that affected vision, including 1 elderly woman with permanent unilateral tarsorrhaphy. Severe HZ eye pain was reported to be directly responsible for 1 unsuccessful suicide attempt. Acute retinal necrosis did not develop in any individual. A mean of 10.8 eye visits per patient with HZ and eye involvement was reported to continue for a mean of 308 days. Eye complications are common and result in considerable health care use and permanent vision decrement in about 6.6% (6) of individuals with HZ eye involvement. Most health care use and long-term adverse outcomes occurred in patients in whom prevention of HZ with the zoster vaccine would be possible. Copyright © 2013 Mayo Foundation for Medical Education and

  13. Eyes of Things

    Directory of Open Access Journals (Sweden)

    Oscar Deniz

    2017-05-01

    Full Text Available Embedded systems control and monitor a great deal of our reality. While some “classic” features are intrinsically necessary, such as low power consumption, rugged operating ranges, fast response and low cost, these systems have evolved in the last few years to emphasize connectivity functions, thus contributing to the Internet of Things paradigm. A myriad of sensing/computing devices are being attached to everyday objects, each able to send and receive data and to act as a unique node in the Internet. Apart from the obvious necessity to process at least some data at the edge (to increase security and reduce power consumption and latency, a major breakthrough will arguably come when such devices are endowed with some level of autonomous “intelligence”. Intelligent computing aims to solve problems for which no efficient exact algorithm can exist or for which we cannot conceive an exact algorithm. Central to such intelligence is Computer Vision (CV, i.e., extracting meaning from images and video. While not everything needs CV, visual information is the richest source of information about the real world: people, places and things. The possibilities of embedded CV are endless if we consider new applications and technologies, such as deep learning, drones, home robotics, intelligent surveillance, intelligent toys, wearable cameras, etc. This paper describes the Eyes of Things (EoT platform, a versatile computer vision platform tackling those challenges and opportunities.

  14. Personal identification by eyes.

    Science.gov (United States)

    Marinović, Dunja; Njirić, Sanja; Coklo, Miran; Muzić, Vedrana

    2011-09-01

    Identification of persons through the eyes is in the field of biometrical science. Many security systems are based on biometric methods of personal identification, to determine whether a person is presenting itself truly. The human eye contains an extremely large number of individual characteristics that make it particularly suitable for the process of identifying a person. Today, the eye is considered to be one of the most reliable body parts for human identification. Systems using iris recognition are among the most secure biometric systems.

  15. The chinchilla eye: morphologic observations, echobiometric findings and reference values for selected ophthalmic diagnostic tests.

    Science.gov (United States)

    Lima, Leandro; Montiani-Ferreira, Fabaino; Tramontin, Mariana; Leigue Dos Santos, Lucianne; Machado, Marcello; Ribas Lange, Rogério; Helena Abil Russ, Heloisa

    2010-09-01

    To carry out a descriptive investigation into the most relevant morphological features of the chinchilla eye and bony orbit, as well as to perform selected ophthalmic diagnostic tests with the aim of establishing normal anatomic and physiologic references for this species. A total of 57 healthy, chinchillas were used to test most of the parameters in this investigation. Besides morphologic observations of the globe and adnexa, selected ocular tests and parameters were investigated, including blink frequency, palpebral fissure length (PFL), Schirmer tear test (STT), esthesiometry, intraocular pressure (IOP), central corneal thickness (CCT), B-mode echobiometric measurements of the globe and culture of the normal conjunctival bacterial microbiota. Morphologic observations were made using six formalin-fixed globes and four macerated skulls. Normal parameters found for selected ocular diagnostic tests were: blink frequency: 2.6 ± 0.84 blinks per 10 min; STT: 1.07 ± 0.54 mm; esthesiometry: 1.24 ± 0.46 cm; IOP: 17.71 ± 4.17 mmHg; CCT: 0.34 ± 0.03 mm; PFL: 1.44 ± 0.11 cm; anterior chamber depth: 2.01 ± 0.2 mm; axial lens thickness: 5.49 ± 0.43 mm; vitreous chamber depth (internal): 3.69 ± 0.52 mm; axial globe length: 1.14 ± 0.07 cm. The most frequent bacteria isolated from the conjunctiva were Streptococcus sp. (27.45%), Staphylococcus aureus (23.52%) and coagulase-negative Staphylococcus (19.60%). No statistically significant differences between left or right eyes or genders were found for any of the results. Reference data and morphologic observations obtained in this investigation will help veterinary ophthalmologists to recognize unique morphological features and more accurately diagnose ocular diseases in the chinchilla, an animal already being used as a biological model for ophthalmic studies.

  16. 瞬目反射在急性面神经炎中的应用价值%The value of blink reflex in facial paralysis

    Institute of Scientific and Technical Information of China (English)

    战丽; 梁冰; 周阳

    2011-01-01

    [目的]探讨瞬目反射对面神经炎早期诊断和病变范围评估的价值.[方法]对60例面神经炎患者在发病1~7 d内进行瞬目反射检查并与神经电图检查作对照.[结果]瞬目反射异常率为100%(60/60),神经电图异常率为46.6%(28/60),差异有统计学意义.瞬目反射提示单纯面神经损害68.3%(41/60),面神经、脑干和三叉神经联合损害19例.[结论]瞬目反射是面神经炎早期诊断的敏感指标,对评估病变范围有助.%[Objective] To explore the value of blink reflex examination on the early diagnosis and extent of facial paralysis.[ Mothods] 60 cases of facial paralysis patients accepted blink reflexes examination and compared with nerve eleetronystagmography examination within 1 to 7 days. [ Results] The blink reflex abnormality rate was 100% (60/60), abnormal nerve diagram was 46.6% (28/60), the ditterenee was statistically significant. Blink reflex in facial nerve damage alone suggested a pure facial nerve damage 68.3%(41/60). Facial nerve, brainstem, and extensive damage to the trigeminal nerve were examined in 19 cases. [Conclusion] The facial blink reflex is a sensitive marker of early diagnosis on facial paralysis and is helpful for the assessment of the extent of the disease.

  17. Eye Formation in Rotating Convection

    CERN Document Server

    Oruba, L; Dormy, E

    2016-01-01

    We consider rotating convection in a shallow, cylindrical domain. We examine the conditions under which the resulting vortex develops an eye at its core; that is, a region where the poloidal flow reverses and the angular momentum is low. For simplicity, we restrict ourselves to steady, axisymmetric flows in a Boussinesq fluid. Our numerical experiments show that, in such systems, an eye forms as a passive response to the development of a so-called eyewall, a conical annulus of intense, negative azimuthal vorticity that can form near the axis and separates the eye from the primary vortex. We also observe that the vorticity in the eyewall comes from the lower boundary layer, and relies on the fact the poloidal flow strips negative vorticity out of the boundary layer and carries it up into the fluid above as it turns upward near the axis. This process is effective only if the Reynolds number is sufficiently high for the advection of vorticity to dominate over diffusion. Finally we observe that, in the vicinity o...

  18. Magnetic eye tracking in mice.

    Science.gov (United States)

    Payne, Hannah L; Raymond, Jennifer L

    2017-09-05

    Eye movements provide insights about a wide range of brain functions, from sensorimotor integration to cognition; hence, the measurement of eye movements is an important tool in neuroscience research. We describe a method, based on magnetic sensing, for measuring eye movements in head-fixed and freely moving mice. A small magnet was surgically implanted on the eye, and changes in the magnet angle as the eye rotated were detected by a magnetic field sensor. Systematic testing demonstrated high resolution measurements of eye position of eye tracking offers several advantages over the well-established eye coil and video-oculography methods. Most notably, it provides the first method for reliable, high-resolution measurement of eye movements in freely moving mice, revealing increased eye movements and altered binocular coordination compared to head-fixed mice. Overall, magnetic eye tracking provides a lightweight, inexpensive, easily implemented, and high-resolution method suitable for a wide range of applications.

  19. 超大视场红外鱼眼告警系统的成像响应特性分析%Imaging response characteristics analysis of ultra-wide field of view infrared fish-eye warning system

    Institute of Scientific and Technical Information of China (English)

    周玉龙; 王永仲

    2011-01-01

    超大视场红外鱼眼告警系统具有凝视半球空域,实时感知来自空中不同方向威胁的独特优点,在未来战争中必将有着广泛的应用.而对超大视场红外鱼眼告警系统的成像响应特性进行分析有助于解决其在应用中所出现的问题.对系统的温度响应特性、时间响应特性以及像面照度进行了分析,结果表明,在相同的环境温度下,系统的温度响应特性是线性的,且随着时间的推移系统的输出逐渐变大,在约70 min以后趋于稳定;当环境温度升高时,系统输出也相应变大,说明系统存在着能量漂移.通过对实验结果的进一步分析,结果表明,这种能量漂移是环境温度和系统的自热效应共同作用的结果.通过对同一目标不同位置处的灰度值进行分析,发现灰度值相对标准偏差仅为2.26%,说明不同位置处目标的灰度值几乎是相等的,从而表明系统的像面照度是均匀的,这与随后的理论分析相一致.对于超大视场红外鱼眼告警系统的算法设计方面具有重要的参考价值.%The ultra-wide field of view(UWFV)infrared fish-eye warning system has the ability of staring hemisphere space so that it can sense the threats from different directions at real time,which makes it be widely used in the future modern wars.It will be helpful in solving the problems in practical application to analyze the thermal imaging response characteristics of UWFV infrared fish-eye warning system.In this paper,the thermal imaging response characteristics including temperature response,time response and image illumination were analyzed respectively for UWFV infrared fish-eye warning system.It was found that under the same ambient temperature condition,the system temperature response was linear.With the process of time,the system output became bigger gradually,and it tended to be a fixed value after about 70 minutes.When the ambient temperature got higher,the system output was also

  20. What Is Dry Eye?

    Medline Plus

    Full Text Available ... vision in the morning? Jun 12, 2017 Can lupus affect my vision? May 27, 2017 Is stopping ... Answers Free Newsletter Get ophthalmologist-reviewed tips and information about eye health and preserving your vision. Privacy ...

  1. Anatomy of the Eye

    Science.gov (United States)

    ... Conditions Frequently Asked Questions Español Condiciones Chinese Conditions Anatomy of the Eye En Español Read in Chinese External (Extraocular) Anatomy Extraocular Muscles: There are six muscles that are ...

  2. Eye Disease and Development

    DEFF Research Database (Denmark)

    Andersen, Thomas Barnebeck; Dalgaard, Carl-Johan Lars; Selaya, Pablo

    This research advances the hypothesis that cross-country variation in the historical incidence of eye disease has influenced the current global distribution of per capita income. The theory is that pervasive eye disease diminished the incentive to accumulate skills, thereby delaying the fertility...... transition and the take-off to sustained economic growth. In order to estimate the influence from eye disease incidence empirically, we draw on an important fact from the field of epidemiology: Exposure to solar ultraviolet B radiation (UVB-R) is an underlying determinant of several forms of eye disease...... are robust to the inclusion of an extensive set of climate and geography controls. Moreover, using a global data set on economic activity for all terrestrial grid cells we show that the link between UVB-R and economic development survives the inclusion of country fixed effect....

  3. About the Eye

    Medline Plus

    Full Text Available ... The Visual System Your Eyes’ Natural Defenses Eye Health and Safety First Aid Tips Healthy Vision Tips ... addressed to the NEI Website Manager . Department of Health and Human Services | The National Institutes of Health | ...

  4. About the Eye

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    Full Text Available ... Units Division of Epidemiology and Clinical Applications eyeGENE Research Directors Office Office of the Scientific Director Sheldon S. Miller, Ph.D., Scientific Director David ...

  5. About the Eye

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    Full Text Available ... of visual function, preservation of sight, and the special health problems and requirements of the blind.” News & ... Emily Y. Chew, M.D., Deputy Clinical Director Education Programs National Eye Health Education Program (NEHEP) Diabetic ...

  6. Eyes, Bulging (Proptosis)

    Science.gov (United States)

    ... a disorder causing overactivity of the thyroid gland ( hyperthyroidism ). Bulging eyes are not the same as prominent ... or pain Whether the person has symptoms of hyperthyroidism, such as inability to tolerate heat, increased sweating, ...

  7. About the Eye

    Medline Plus

    Full Text Available ... The Visual System Your Eyes’ Natural Defenses Eye Health and Safety First Aid Tips Healthy Vision Tips ... addressed to the NEI Website Manager . Department of Health and Human Services | The National Institutes of Health | ...

  8. About the Eye

    Medline Plus

    Full Text Available ... about each part of your eye and what it does. Macula (MACK-yoo-luh) is the small, ... area of the retina needed for central vision. It contains the fovea. Lens is the clear part ...

  9. What Is Eye Cancer?

    Science.gov (United States)

    ... melanomas. Melanomas develop from pigment-making cells called melanocytes . When melanoma develops in the eye, it is ... cells make the same kind of pigment as melanocytes in the skin, so it’s not surprising that ...

  10. What Is Dry Eye?

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    Full Text Available ... Plastic Surgery Center Laser Surgery Education Center Redmond Ethics Center Global Ophthalmology Guide Academy Publications EyeNet Ophthalmology ... Plastic Surgery Center Laser Surgery Education Center Redmond Ethics Center Global Ophthalmology Guide Find an Ophthalmologist Advanced ...

  11. About the Eye

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    Full Text Available ... Units Division of Epidemiology and Clinical Applications eyeGENE Research Directors Office Office of the Scientific Director Sheldon S. ... Fellowships NEI Summer Intern Program Diversity In Vision Research & Ophthalmology (DIVRO) Student Training Programs To search for ...

  12. Sports and Your Eyes

    Science.gov (United States)

    ... may put you at high risk for eye injuries. Baseball Basketball Water Sports Boxing Hockey Paintball Racquetball Softball Squash Fencing Lacrosse Wrestling Football Golf Badminton Soccer Tennis Fishing Bicycling Gymnastics Track ...

  13. Diabetic Eye Problems

    Science.gov (United States)

    ... damage your eyes. The most common problem is diabetic retinopathy. It is a leading cause of blindness ... You need a healthy retina to see clearly. Diabetic retinopathy damages the tiny blood vessels inside your ...

  14. What Is Dry Eye?

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    Full Text Available ... Plastic Surgery Center Laser Surgery Education Center Redmond Ethics Center Global Ophthalmology Guide Academy Publications EyeNet Ophthalmology Information for: International Ophthalmologists Media Medical Students Patients and Public Technicians and Nurses ...

  15. About the Eye

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    Full Text Available ... NEI Women Scientists Advisory Committee (WSAC) Board of Scientific Counselors National Advisory Eye Council (NAEC) Donating to ... Grants and Funding Extramural Research Division of Extramural Science Programs Division of Extramural Activities Extramural Contacts NEI ...

  16. What Is Dry Eye?

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    Full Text Available ... Eye May 03, 2012 Follow The Academy Professionals: Education Guidelines News Multimedia Public & Patients: Contact Us About the Academy Jobs at the Academy Financial Relationships with Industry Medical ...

  17. The ageing eye

    African Journals Online (AJOL)

    2007-10-11

    Oct 11, 2007 ... With an increasing elderly population, age-related eye diseases are becoming the leading causes of ... and social health and overall quality of life. Enormous strides are ..... hip fractures, accidents and depression. Conclusion.

  18. Multimodal eye recognition

    Science.gov (United States)

    Zhou, Zhi; Du, Yingzi; Thomas, N. L.; Delp, Edward J., III

    2010-04-01

    Multimodal biometrics use more than one means of biometric identification to achieve higher recognition accuracy, since sometimes a unimodal biometric is not good enough used to do identification and classification. In this paper, we proposed a multimodal eye recognition system, which can obtain both iris and sclera patterns from one color eye image. Gabor filter and 1-D Log-Gabor filter algorithms have been applied as the iris recognition algorithms. In sclera recognition, we introduced automatic sclera segmentation, sclera pattern enhancement, sclera pattern template generation, and sclera pattern matching. We applied kernelbased matching score fusion to improve the performance of the eye recognition system. The experimental results show that the proposed eye recognition method can achieve better performance compared to unimodal biometric identification, and the accuracy of our proposed kernel-based matching score fusion method is higher than two classic linear matching score fusion methods: Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA).

  19. What Is Dry Eye?

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    Full Text Available ... Dry Eye Symptoms Related Ask an Ophthalmologist Answers Can a six-month dissolvable punctal plug be removed ... insert a permanent punctal plug? Sep 12, 2017 Can you explain why I have halos and blurry ...

  20. Eye Injuries in Construction

    Science.gov (United States)

    ... from a power tool (like a drill or wheel) , OR ! If your eye is cut or punctured : • ... CIO: CPWR, Suite 1000, 8484 Georgia Ave., Silver Spring, MD 20910. (Edward C. Sullivan is president of ...