Event-related brain potentials (ERPs) provide high-resolution
 measures of the time course of neuronal activity patterns associated
 with perceptual and cognitive processes. New techniques for ERP source
 analysis and comparisons with data from blood-flow neuroimaging studies
 enable improved localization of cortical activity during visual
 selective attention. ERP modulations during spatial attention point
 toward a mechanism of gain control over information flow in
 extrastriate visual cortical pathways, starting about 80 ms after
 stimulus onset. Paying attention to nonspatial features such as color,
 motion, or shape is manifested by qualitatively different ERP patterns
 in multiple cortical areas that begin with latencies of 100–150 ms.
 The processing of nonspatial features seems to be contingent upon the
 prior selection of location, consistent with early selection theories
 of attention and with the hypothesis that spatial attention is
 “special.”

https://www.pnas.org/content/pnas/95/3/781.full.pdf

Event-related brain potentials in the study of visual selective attention

Both physiological and behavioral studies have suggested that stimulus-driven neural activity in the sensory pathways can be modulated in amplitude during selective attention. Recordings of event-related brain potentials indicate that such sensory gain control or amplification processes play an important role in visual-spatial attention. Combined event-related brain potential and neuroimaging experiments provide strong evidence that attentional gain control operates at an early stage of visual processing in extrastriate cortical areas. These data support early selection theories of attention and provide a basis for distinguishing between separate mechanisms of attentional suppression (of unattended inputs) and attentional facilitation (of attended inputs).

/pdf/sensory-gain-control-amplification-as-a-mechanism-of-1dmua2zg02.pdf

Sensory gain control (amplification) as a mechanism of selective attention: electrophysiological and neuroimaging evidence

This study aimed to characterize the neural generators of the early components of the visual evoked potential (VEP) to isoluminant checkerboard stimuli. Multichannel scalp recordings, retinotopic mapping and dipole modeling techniques were used to estimate the locations of the cortical sources giving rise to the early C1, P1, and N1 components. Dipole locations were matched to anatomical brain regions visualized in structural magnetic resonance imaging (MRI) and to functional MRI (fMRI) activations elicited by the same stimuli. These converging methods confirmed previous reports that the C1 component (onset latency 55 msec; peak latency 90-92 msec) was generated in the primary visual area (striate cortex; area 17). The early phase of the P1 component (onset latency 72-80 msec; peak latency 98-110 msec) was localized to sources in dorsal extrastriate cortex of the middle occipital gyrus, while the late phase of the P1 component (onset latency 110-120 msec; peak latency 136-146 msec) was localized to ventral extrastriate cortex of the fusiform gyrus. Among the N1 subcomponents, the posterior N150 could be accounted for by the same dipolar source as the early P1, while the anterior N155 was localized to a deep source in the parietal lobe. These findings clarify the anatomical origin of these VEP components, which have been studied extensively in relation to visual-perceptual processes.

/pdf/cortical-sources-of-the-early-components-of-the-visual-2fmbwh0uuy.pdf

Cortical sources of the early components of the visual evoked potential

https://www.cogsci.ucsd.edu/~coulson/cogs179/attention-tics.pdf

Event-related potential studies of attention

Here we used magnetoencephalography (MEG) to investigate stages of processing in face perception in humans. We found a face-selective MEG response occurring only 100 ms after stimulus onset (the 'M100'), 70 ms earlier than previously reported. Further, the amplitude of this M100 response was correlated with successful categorization of stimuli as faces, but not with successful recognition of individual faces, whereas the previously-described face-selective 'M170' response was correlated with both processes. These data suggest that face processing proceeds through two stages: an initial stage of face categorization, and a later stage at which the identity of the individual face is extracted.

Stages of processing in face perception: an MEG study.

In a study of the neural processes that mediate visual attention in humans, 32-channel recordings of event-related potentials were obtained from 14 normal subjects while they performed a spatial attention task. The generator locations of the early C1, P1, and Nl components of the visual evoked response were estimated by means of topographic maps of voltage and current source density in conjunction with dipole modelling. The topography of the C1 component (ca. 85 ms post-stimulus) was consistent with a generator in striate cortex, and this component was unaffected by attention. In contrast, the P1 and Nl components (ca. 95 and 170ms) exhibited current density foci at scalp sites overlying lateral extrastriate cortex and were larger for attended stimuli than for unattended stimuli. The voltage topographies in the 75–175 ms latency range were modeled with a 5-dipole configuration consisting of a single striate dipole and left-right pairs of dipoles located in lateral extrastriate and inferior occipito-temporal areas. This model was found to account for the voltage topographies produced by both attended and unattended stimuli with low residual variance. These results support the proposal that visual-spatial attention modulates neural activity in extrastriate visual cortex but does not affect the initial evoked response in striate cortex.

Sources of attention-sensitive visual event-related potentials.

Fronto–temporo–occipital activity changes with age during a visual working memory developmental study in children, adolescents and adults

The present study analyzes the development of the visual recognition processing of the relevant stimulus in a Delayed Match-To-Sample (DMS) task during the matching phase. To do so, Electroencephalograms of 170 subjects between 6 and 26 years old were recorded. Behavioral responses and Event Related Potentials (ERPs) induced by the stimuli were obtained. Reaction times and errors, mainly omissions, were inversely related to age. The ERPs analysis showed a parietal negativity in the P7 and P8 electrodes when the relevant stimulus was presented in the contralateral site. This negativity resulting from the recognition and selection of the relevant stimulus was present in all age groups. However, the youngest children showed an extended latency in the recognition process. The results suggest that children and adults use similar processes to recognize the item maintained in visual short-term memory (VSTM), but children need more time to successfully recognize the memorized item.

/pdf/electrophysiological-evidence-of-a-delay-in-the-visual-2mfwe70uct.pdf

Carlos M. Gómez González

Papers

Sources of attention-sensitive visual event-related potentials.

Fronto–temporo–occipital activity changes with age during a visual working memory developmental study in children, adolescents and adults

Electrophysiological Evidence of a Delay in the Visual Recognition Process in Young Children.