Brain dynamics associated with perisaccadic time perception: an EEG / graph theory approach

Poster Session D - Monday, April 15, 2024, 8:00 – 10:00 am EDT, Sheraton Hall ABC

Amirhossein Ghaderi¹ (ghaderi@yorku.ca), Matthias Niemeier^1,2, John Douglas Crawford¹; ¹York University, ²University of Toronto

Numerous studies have shown that saccades influence time perception, but the associated neural mechanisms remain elusive. We explored the cortical dynamics of perisaccadic time perception through a combination psychophysics, EEG, sLORETA source localization, and graph theory analysis. 21 participants viewed a sequence of reference stimuli followed by a test stimulus, either just before saccades or sustained fixation. Following this, participants were asked to judge the duration of the test stimulus compared to the reference. In previous studies we found that stimulus repetition and saccades events interacted at the level of sensorimotor brain dynamics (Ghaderi et al. Cerebral Cortex 2023) and perceived stimulus duration (Ghaderi et al. Heliyon 2022). Here, we combined these two approaches to investigate brain dynamics related to perceived stimulus duration (underestimation vs. correct). Source localization revealed the temporal dynamics in cortical activation, predominantly starting from early visual and concluding in higher-level ‘cognitive’ areas (middle frontal and anterior cingulate cortices). The graph theory analysis highlighted the pivotal roles of three groups of brain regions: 1) visual, 2) temporal and parahippocampal, and 3) frontal and anterior cingulate cortices. Furthermore, the whole network analysis revealed significant differences in the topological and dynamical features of brain networks between underestimated trials and those with correct judgments. These findings suggest the involvement of multiple cortical regions, potentially linked to various cognitive functions such as sensory processing, memory, and higher-order cognition. Moreover, the results imply that time distortion might be associated with higher-level neural processing within functional brain networks. Supported by NSERC funding.

Topic Area: PERCEPTION & ACTION: Multisensory