Intracranial Neural Dynamics of Selective Attention in Rapid Visual Recognition

Poster Session A - Saturday, April 13, 2024, 2:30 – 4:30 pm EDT, Sheraton Hall ABC

Meredith McCarty^1,2 (meredith.j.mccarty@uth.tmc.edu), Oscar Woolnough^1,2, Elliot Murphy^1,2, Nitin Tandon^1,2,3; ¹Texas Institute for Restorative Neurotechnologies, The University of Texas Health Science Center at Houston, ²Vivian L. Smith Department of Neurosurgery, McGovern Medical School, ³Memorial Hermann Hospital, Texas Medical Center

Selective attention enables the flexible direction of neural resources towards behaviorally relevant stimuli. The neural substrate of attention is proposed to be oscillatory coupling between task-relevant brain regions, indexed by activity in distinct frequency bands. Rapid visual recognition involves activation in category-selective regions of the ventral occipitotemporal cortex (vOTC), however prior work has found vOTC activation to scale with task demands, suggesting a task-driven recruitment of amodal substrates. To probe these dynamics, we utilize intracranial electroencephalographic recordings in 25 patients (14 female) performing a task where visual attention is directly modulated. In this task, visual stimuli of different categories (Faces, Words, Scenes, or Animals) were presented. Across different trial blocks, patients tracked and responded to one specific feature: a color change of a central fixation point, repetition of a stimulus (i.e. a one-back task), or the category the stimulus belonged to (e.g., the category “fruit or vegetable words” for which an exemplar is “apple”). This task design enables the isolation of attentional dynamics when the same stimuli are presented, but task demands shift. Through implementing a d-prime selectivity analysis on broadband high gamma activity (70-150Hz), we identified electrodes that exhibit significant category-selectivity. We found significant sustained increase in BGA in frontal regions as task demand increased. We identified significant task-based modulation of bidirectional alpha-band Granger causality between vOTC and frontal cortex. Through quantifying information flow between these regions, we identify a potential mechanism by which the frontal cortex modulates vOTC activity based on selective attention.

Topic Area: ATTENTION: Nonspatial