Interacting cortical gradients of neural timescales and functional connectivity and their relationship to perceptual behavior

Abstract

Cognitive acts take place over a large range of temporal scales. Numerous corresponding gradients in neurodynamic timescales and long-range cortical interactions are believed to provide organizational constraints to the brain and influence neural populations roles in cognition. However, it is unclear if gradients in various types of neural timescales and functional connectivity arise from related or distinct neurophysiological processes and if they influence behavior. Here, intracranial recordings from 4,090 electrode contacts in 35 individuals were used to systematically map gradients of multiple aspects of neurodynamics, neural timescales, and functional connectivity, and assess their interactions along category-selective ventral temporal cortex. Opposing functional connectivity gradients, with decreasing connectivity to visually responsive regions and increasing connectivity to regions that were not visually responsive, were observed along the ventral visual hierarchy. Endogenous neural timescales were correlated with functional connectivity to visually responsive regions after removing the effects of shared anatomical gradients, suggesting that these properties influence one another. Different stimulus evoked and endogenous timescales exhibited gradients with longer dynamics along the ventral visual hierarchy, but none of these timescales were significantly correlated with one another. This suggests that local neural timescales depend on neural and cognitive context and different timescales may arise through distinct neurophysiological processes. Furthermore, activity from neural populations with faster endogenous timescales and stronger functional connectivity to visually responsive regions was more predictive of perceptual behavior during a visual repeat detection task. These results reveal interrelationships and key distinctions among neural timescale and functional connectivity gradients that together can influence behavior.