Christison-Lagay, K. | Search bioRxiv

bioRxiv2024

The Neural Basis of Attentional Blink as a Selective Control Mechanism in Conscious Perception

Conscious perception of visual stimuli involves large-scale brain networks with multiple activation-deactivation dynamics. Previous works have shown that early detection networks may be switched off about 200ms to 300ms after presentation of a visual stimulus. We hypothesize that these deactivations represent a selective control mechanism of the brain to conserve resources for post-perceptual processing. To this end, we used attentional blink as a behavioral measure for this mechanism. We showed that attentional blink is more likely to occur when a previous visual stimulus was consciously perceived. Using high-resolution eye-tracking, we found prolonged decrease in pupil diameter and transient decrease in blink probability associated with attentional blink. Using scalp EEG data, we further showed that attentional blink is associated with more pronounced event-related potentials related to visual processing and report. One sentence summaryattentional blink may represent a selective control mechanism of neural processing resources underlying conscious perception.

neuroscience↗

bioRxiv2021

Early neural activity changes associated with visual conscious perception

The neural mechanisms of visual conscious perception have been investigated for decades. However, the spatiotemporal dynamics associated with the earliest neural responses following consciously perceived stimuli are still poorly understood. Using a dataset of intracranial EEG recordings, the current study aims to investigate the neural activity changes associated with the earliest stages of visual conscious perception. Subjects (N=10, 1,693 grey matter electrode contacts) completed a continuous performance task in which individual letters were presented in series and subjects were asked to press a button when they saw a target letter. Broadband gamma power (40-115Hz) dynamics were analyzed in comparison to baseline prior to stimulus and contrasted for target trials with button presses and non-target trials without button presses. Regardless of event type, we observed early gamma power changes within 30-150 ms from stimulus onset in a network including increases in bilateral occipital, fusiform, frontal (including frontal eye fields), and medial temporal cortex, increases in left lateral parietal-temporal cortex, and decreases in the right anterior medial occipital cortex. No significant differences were observed between target and non-target stimuli until >150 ms post-stimulus, when we saw greater gamma power increases in left motor and premotor areas, suggesting a possible role of these later signals in perceptual decision making and/or motor responses with the right hand. The early gamma power findings suggest a broadly distributed cortical visual detection network that is engaged at early times tens of milliseconds after signal transduction from the retina.

neuroscience↗