scholarly journals Neural Site of the Redundant Target Effect: Electrophysiological Evidence

1998 ◽  
Vol 10 (2) ◽  
pp. 216-230 ◽  
Author(s):  
C. Miniussi ◽  
M. Girelli ◽  
C. A. Marzi
Keyword(s):  
Visual Processing ◽  
Event Related Potentials ◽  
Probability Summation ◽  
Redundant Target Effect ◽  
Early Visual Processing ◽  
Visual Hemifield ◽  
Related Potentials ◽  
Target Effect ◽  
Electrophysiological Correlate ◽  
Double Targets

The present study represents an attempt to find an electrophysiological correlate of the redundant targets effect, or RTE (i.e., the speeding up of reaction time, or RT, for redundant vs. single targets). Subjects made a speeded response either to one small checkerboard presented to the left or right of fixation or to a pair of identical checkerboards presented simultaneously to both hemifields. Both single and double targets could appear either in the upper or lower visual hemifield. The task required detection but not discrimination of the stimuli. During task performance, we recorded the event-related potentials (ERPs) elicited by the checkerboard targets. As in previous studies, we found that manual RTs to bilateral stimuli were faster than those to unilateral stimuli. This effect was more marked for lower-than for upper-field stimuli and could not be ascribed to probability summation. In addition, we found that the P1 and N1 components of the visual ERP had a shorter latency for bilateral than for summed unilateral stimuli presented to the two hemifields. In parallel with the behavioral findings, the latency values for the above components showed a larger RTE for lower-field stimuli. These findings indicate that the RTE occurs at the level of early visual processing, probably in the extrastriate visual cortex, rather than at late decisional or pre-motor stages.

scholarly journals Age-related differences in event-related potentials for early visual processing of emotional faces

2013 ◽  
Vol 9 (7) ◽  
pp. 969-976 ◽  
Author(s):  
Matthew R. Hilimire ◽  
Andrew Mienaltowski ◽  
Fredda Blanchard-Fields ◽  
Paul M. Corballis
Keyword(s):  
Visual Processing ◽  
Event Related Potentials ◽  
Emotional Faces ◽  
Early Visual Processing ◽  
Age Related ◽  
Related Potentials

scholarly journals Does Creativity Influence Visual Perception? - An Event-Related Potential Study With Younger and Older Adults

2021 ◽  
Vol 12 ◽  
Author(s):  
Petra Csizmadia ◽  
István Czigler ◽  
Boglárka Nagy ◽  
Zsófia Anna Gaál
Keyword(s):  
Visual Processing ◽  
Healthy Aging ◽  
Early Stage ◽  
Event Related Potentials ◽  
Event Related Potential ◽  
Oddball Paradigm ◽  
Top Down ◽  
Early Visual Processing ◽  
Related Potentials ◽  
Creative Group

We do not know enough about the cognitive background of creativity despite its significance. Using an active oddball paradigm with unambiguous and ambiguous portrait paintings as the standard stimuli, our aim was to examine whether: creativity in the figural domain influences the perception of visual stimuli; any stages of visual processing; or if healthy aging has an effect on these processes. We investigated event related potentials (ERPs) and applied ERP decoding analyses in four groups: younger less creative; younger creative; older less creative; and older creative adults. The early visual processing did not differ between creativity groups. In the later ERP stages the amplitude for the creative compared with the less creative groups was larger between 300 and 500 ms. The stimuli types were clearly distinguishable: within the 300–500 ms range the amplitude was larger for ambiguous rather than unambiguous paintings, but this difference in the traditional ERP analysis was only observable in the younger, not elderly groups, who also had this difference when using decoding analysis. Our results could not prove that visual creativity influences the early stage of perception, but showed creativity had an effect on stimulus processing in the 300–500 ms range, in indexing differences in top-down control, and having more flexible cognitive control in the younger creative group.

Movement-Related Potentials and Event-Related Potentials

2016 ◽  
pp. 693-699
Author(s):  
Rene L. Utianski ◽  
John N. Caviness
Keyword(s):  
Neurological Disease ◽  
Rare Event ◽  
Event Related Potentials ◽  
Cortical Activity ◽  
Auditory Stimulation ◽  
Related Potentials ◽  
The Subject ◽  
P Movement ◽  
Electrophysiological Correlate ◽  
Semantic Comprehension

Movement-related cortical potentials (MRCPs) are EEG potentials that occur with movement and are recorded using surface scalp electrodes. A technique termed “EEG-EMG back-averaging” is used to obtain MRCPs. The earliest recordable MRCP is the Bereitschaftspotential or readiness potential. Special EEG averaging techniques may also be used to study the cortical processes underlying cognition. Event-related potentials (ERPs) record the cortical activity evoked by a stimulus charged with cognitive significance. The P300 is the most commonly recorded ERP, elicited in an oddball technique of auditory stimulation; the subject is instructed to attend to a rare stimulus presented among a string of frequent stimuli. Only trials triggered by this rare event are averaged. The P300 may be the electrophysiological correlate of selected attention. The N400, another ERP, is assessed during semantic comprehension of language. The chapter discusses normal variants of MRCPs and ERPs, as well as disruptions secondary to neurological disease.

Inter- and Intra-hemispheric Processing of Visual Event-related Potentials in the Absence of the Corpus Callosum

2004 ◽  
Vol 16 (3) ◽  
pp. 401-414 ◽  
Author(s):  
Sophie Bayard ◽  
Nadia Gosselin ◽  
Manon Robert ◽  
Maryse Lassonde
Keyword(s):  
Corpus Callosum ◽  
Anterior Commissure ◽  
Event Related Potentials ◽  
Interhemispheric Transfer ◽  
P300 Amplitude ◽  
Oddball Paradigm ◽  
P300 Latency ◽  
Hemispheric Differences ◽  
Visual Hemifield ◽  
Related Potentials

Interhemispheric differences of the N100 latency in visual evoked potentials have been used to estimate interhemispheric transfer time (e.g., Saron & Davidson, 1989). Recent work has also suggested that the P300 component could reflect the efficacy of interhemispheric transmission (Polich & Hoffman, 1998). The purpose of the present study was to study the differential role of the corpus callosum (CC) and anterior commissure (AC) in the interhemispheric propagation of these two electrophysiological components. Thus, the amplitude and latency distribution of the N100 and P300 components were analyzed using high-density electrical mapping in a subject with agenesis of CC but preservation of AC, a subject with agenesis of both CC and AC, and 10 neurologically intact control subjects. The task consisted of a modified visual oddball paradigm comprising one frequent and two rare stimuli, one presented on the same and the other on the opposite side of the frequent stimulus. Interhemispheric differences in latency were found for the N100 component in controls. However, in the acallosal subjects, this component was not identifiable in the indirectly stimulated hemisphere. In controls, no interhemispheric differences were observed in the distribution of the P300 latency and amplitude to rare and frequent stimuli. The distribution of the P300 amplitude in the acallosal subject with an AC was identical to that of the controls, whereas in the acallosal subject lacking the AC, the amplitude was greater in the hemisphere receiving the frequent stimuli, regardless of the visual hemifield in which the rare stimuli were presented. In both acallosal subjects, hemispheric differences in the P300 latency were observed, the latencies being shorter in the hemisphere directly stimulated for all categories of stimuli. These results suggest that the interhemispheric transfer of both the N100 and P300 components relies on the integrity of cortical commissures. Possible P300 generator sources are discussed.

scholarly journals A P300 Brain-Computer Interface With a Reduced Visual Field

2020 ◽  
Vol 14 ◽  
Author(s):  
Luiza Kirasirova ◽  
Vladimir Bulanov ◽  
Alexei Ossadtchi ◽  
Alexander Kolsanov ◽  
Vasily Pyatin ◽  
...  
Keyword(s):  
Visual Field ◽  
Visual Processing ◽  
Classification Accuracy ◽  
Peripheral Vision ◽  
Brain Computer Interface ◽  
Event Related Potentials ◽  
Computer Interface ◽  
Central Visual Field ◽  
P300 Speller ◽  
Related Potentials

A P300 brain-computer interface (BCI) is a paradigm, where text characters are decoded from event-related potentials (ERPs). In a popular implementation, called P300 speller, a subject looks at a display where characters are flashing and selects one character by attending to it. The selection is recognized as the item with the strongest ERP. The speller performs well when cortical responses to target and non-target stimuli are sufficiently different. Although many strategies have been proposed for improving the BCI spelling, a relatively simple one received insufficient attention in the literature: reduction of the visual field to diminish the contribution from non-target stimuli. Previously, this idea was implemented in a single-stimulus switch that issued an urgent command like stopping a robot. To tackle this approach further, we ran a pilot experiment where ten subjects operated a traditional P300 speller or wore a binocular aperture that confined their sight to the central visual field. As intended, visual field restriction resulted in a replacement of non-target ERPs with EEG rhythms asynchronous to stimulus periodicity. Changes in target ERPs were found in half of the subjects and were individually variable. While classification accuracy was slightly better for the aperture condition (84.3 ± 2.9%, mean ± standard error) than the no-aperture condition (81.0 ± 2.6%), this difference was not statistically significant for the entire sample of subjects (N = 10). For both the aperture and no-aperture conditions, classification accuracy improved over 4 days of training, more so for the aperture condition (from 72.0 ± 6.3% to 87.0 ± 3.9% and from 72.0 ± 5.6% to 97.0 ± 2.2% for the no-aperture and aperture conditions, respectively). Although in this study BCI performance was not substantially altered, we suggest that with further refinement this approach could speed up BCI operations and reduce user fatigue. Additionally, instead of wearing an aperture, non-targets could be removed algorithmically or with a hybrid interface that utilizes an eye tracker. We further discuss how a P300 speller could be improved by taking advantage of the different physiological properties of the central and peripheral vision. Finally, we suggest that the proposed experimental approach could be used in basic research on the mechanisms of visual processing.

scholarly journals Event-Related Potential Evidence of Enhanced Visual Processing in Auditory-Associated Cortex in Adults with Hearing Loss

2020 ◽  
Vol 25 (5) ◽  
pp. 237-248
Author(s):  
Maojin Liang ◽  
Jiahao Liu ◽  
Yuexin Cai ◽  
Fei Zhao ◽  
Suijun Chen ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Visual Processing ◽  
Event Related Potentials ◽  
Event Related Potential ◽  
Occipital Area ◽  
Mapping Analysis ◽  
Related Potentials ◽  
The Difference ◽  
The Right ◽  
Frontotemporal Area

Objective: The present study investigated the characteristics of visual processing in the auditory-associated cortex in adults with hearing loss using event-related potentials. Methods: Ten subjects with bilateral postlingual hearing loss were recruited. Ten age- and sex-matched normal-hearing subjects were included as controls. Visual (“sound” and “non-sound” photos)-evoked potentials were performed. The P170 response in the occipital area as well as N1 and N2 responses in FC3 and FC4 were analyzed. Results: Adults with hearing loss had higher P170 amplitudes, significantly higher N2 amplitudes, and shorter N2 latency in response to “sound” and “non-sound” photo stimuli at both FC3 and FC4, with the exception of the N2 amplitude which responded to “sound” photo stimuli at FC3. Further topographic mapping analysis revealed that patients had a large difference in response to “sound” and “non-sound” photos in the right frontotemporal area, starting from approximately 200 to 400 ms. Localization of source showed the difference to be located in the middle frontal gyrus region (BA10) at around 266 ms. Conclusions: The significantly stronger responses to visual stimuli indicate enhanced visual processing in the auditory-associated cortex in adults with hearing loss, which may be attributed to cortical visual reorganization involving the right frontotemporal cortex.

scholarly journals Anorexia nervosa and body dysmorphic disorder are associated with abnormalities in processing visual information

2015 ◽  
Vol 45 (10) ◽  
pp. 2111-2122 ◽  
Author(s):  
W. Li ◽  
T. M. Lai ◽  
C. Bohon ◽  
S. K. Loo ◽  
D. McCurdy ◽  
...  
Keyword(s):  
Anorexia Nervosa ◽  
Spatial Frequency ◽  
Visual Processing ◽  
Visual Information ◽  
Body Dysmorphic Disorder ◽  
High Spatial Frequency ◽  
Event Related Potentials ◽  
Visual Stream ◽  
N170 Component ◽  
Related Potentials

BackgroundAnorexia nervosa (AN) and body dysmorphic disorder (BDD) are characterized by distorted body image and are frequently co-morbid with each other, although their relationship remains little studied. While there is evidence of abnormalities in visual and visuospatial processing in both disorders, no study has directly compared the two. We used two complementary modalities – event-related potentials (ERPs) and functional magnetic resonance imaging (fMRI) – to test for abnormal activity associated with early visual signaling.MethodWe acquired fMRI and ERP data in separate sessions from 15 unmedicated individuals in each of three groups (weight-restored AN, BDD, and healthy controls) while they viewed images of faces and houses of different spatial frequencies. We used joint independent component analyses to compare activity in visual systems.ResultsAN and BDD groups demonstrated similar hypoactivity in early secondary visual processing regions and the dorsal visual stream when viewing low spatial frequency faces, linked to the N170 component, as well as in early secondary visual processing regions when viewing low spatial frequency houses, linked to the P100 component. Additionally, the BDD group exhibited hyperactivity in fusiform cortex when viewing high spatial frequency houses, linked to the N170 component. Greater activity in this component was associated with lower attractiveness ratings of faces.ConclusionsResults provide preliminary evidence of similar abnormal spatiotemporal activation in AN and BDD for configural/holistic information for appearance- and non-appearance-related stimuli. This suggests a common phenotype of abnormal early visual system functioning, which may contribute to perceptual distortions.

scholarly journals Human posterior parietal cortex responds to visual stimuli as early as peristriate occipital cortex

2018 ◽  
Author(s):  
Tamar I. Regev ◽  
Jonathan Winawer ◽  
Edden M. Gerber ◽  
Robert T. Knight ◽  
Leon Y. Deouell
Keyword(s):  
Visual Processing ◽  
Posterior Parietal Cortex ◽  
Right Hemisphere ◽  
Intractable Epilepsy ◽  
Event Related Potentials ◽  
Visual Responses ◽  
Baseline Activity ◽  
Visual Areas ◽  
Related Potentials ◽  
Posterior Parietal

AbstractMuch of what is known about the timing of visual processing in the brain is inferred from intracranial studies in monkeys, with human data limited to mainly non-invasive methods with lower spatial resolution. Here, we estimated visual onset latencies from electrocorticographic (ECoG) recordings in a patient who was implanted with 112 sub-dural electrodes, distributed across the posterior cortex of the right hemisphere, for pre-surgical evaluation of intractable epilepsy. Functional MRI prior to surgery was used to determine boundaries of visual areas. The patient was presented with images of objects from several categories. Event Related Potentials (ERPs) were calculated across all categories excluding targets, and statistically reliable onset latencies were determined using a bootstrapping procedure over the single trial baseline activity in individual electrodes. The distribution of onset latencies broadly reflected the known hierarchy of visual areas, with the earliest cortical responses in primary visual cortex, and higher areas showing later responses. A clear exception to this pattern was robust, statistically reliable and spatially localized, very early responses on the bank of the posterior intra-parietal sulcus (IPS). The response in the IPS started nearly simultaneously with responses detected in peristriate visual areas, around 60 milliseconds post-stimulus onset. Our results support the notion of early visual processing in the posterior parietal lobe, not respecting traditional hierarchies, and give direct evidence for the upper limit of onset times of visual responses across the human cortex.

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