Saturating Nonlinearities of Contrast Response in Human Visual Cortex

• DOI: 10.1523/jneurosci.0106-21.2021
• Publication Date: 2021-12-17T18:50:52Z
• Authors: Louis N. Vinke; Ilona M. Bloem; Sam Ling
• Keywords: Stimulus (psychology); Human brain; Visual processing; Sensory cortex

Response nonlinearities are ubiquitous throughout the brain, especially within sensory cortices where changes in stimulus intensity typically produce compressed responses. Although this relationship is well established electrophysiological measurements, it remains controversial whether same hold for population-based measurements obtained with human fMRI. We propose that these purported disparities not contingent on measurement type and instead largely dependent visual system state at time of interrogation. show deploying a contrast adaptation paradigm permits reliable saturating sigmoidal response functions (10 participants, 7 female). When controlling state, our results coincide previous fMRI studies, yielding nonsaturating, linear These findings highlight important role manifesting measurable nonlinear responses cortex, reconciling discrepancies reported vision neuroscience, re-establishing qualitative between across different neural measures concerted study cortical gain control. SIGNIFICANCE STATEMENT Nonlinear stimulus–response relationships govern many essential brain functions, ranging from to cognitive level. Certain core properties previously shown be nonhuman electrophysiology recordings have yet reliably measured neuroimaging, prompting uncertainty reconsideration. The stand reconcile incongruencies neurosciences, demonstrating profound impact can activation early cortex. Moving forward, facilitate modulatory influences processing (i.e., arousal attention) help establish closer link animals hemodynamic fMRI, resuming effort understand operations mammalian