How does cognitive arousal modulate visuocortical contrast response functions?

• DOI: 10.1167/jov.23.9.5516
• Publication Date: 2023-08-29T18:44:08Z
• Authors: Sam Ling; Louis Vinke; Joseph McGuire; Jasmine Pan
• Keywords: Pupillometry; Numerosity adaptation effect

Although animal work suggests that arousal state has a profound impact on visual responses, the effects human vision remain less well understood. To better characterize mechanisms by which affects perception, in this study we assessed influence of task difficulty gain visuocortical contrast response functions (CRFs). do so, leveraged an adaptation paradigm homogenizes population allowing us to measure compressive, nonlinear CRFs with fMRI. After adapting cortex (adapter: 16% contrast), then measured BOLD responses early (V1-V3) while participants (n=14) viewed grating stimuli varying from trial (9 levels, 3% 96% contrast). While viewing stimuli, observers were instructed concurrently solve auditory arithmetic problems categorized as either Easy (low arousal) or Hard (high arousal). obtain activity, used deconvolution analysis voxel-wise level. Our results revealed surprisingly diverse pattern modulatory across individuals: some individuals displayed enhanced neural increased cognitive arousal, others opposite effect: decrease arousal. This diversity was not spurious: cross-validation analyses verified these patterns quite consistent within participants. Moreover, found individual’s modulation correlated arousal-driven changes their pupil size, such larger differences between two conditions corresponded decreases We speculate polarity modulates may relate individual effort expended conditions, falling different points Yerkes-Dodson curve.