Modulation of brain signal variability in visual cortex reflects aging, GABA, and behavior.

ABSTRACT: Moment-to-moment neural variability has been shown to scale positively with the complexity of stimulus input. However, the mechanisms underlying the ability to align variability to input complexity are unknown. Using a combination of behavioral methods, computational modeling, fMRI, MR spectroscopy, and pharmacological intervention, we investigated the role of aging and GABA in neural variability during visual processing. We replicated previous findings that participants expressed higher variability when viewing more complex visual stimuli. Additionally, we found that such variability modulation was associated with higher baseline visual GABA levels and was reduced in older adults. When pharmacologically increasing GABA activity, we found that participants with lower baseline GABA levels s

SUBMITTER: Lalwani P 

PROVIDER: S-EPMC12005714 | biostudies-literature | 2025 Apr

REPOSITORIES: biostudies-literature