RT Journal Article
SR Electronic
T1 Clarifying the role of higher-level cortices in resolving perceptual ambiguity using Ultra High Field fMRI
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2020.05.27.119677
DO 10.1101/2020.05.27.119677
A1 Logan Dowdle
A1 Geoffrey Ghose
A1 Kamil Ugurbil
A1 Essa Yacoub
A1 Luca Vizioli
YR 2020
UL http://biorxiv.org/content/early/2020/11/17/2020.05.27.119677.abstract
AB The brain is organized into distinct, flexible networks. Within these networks, cognitive variables such as attention can modulate sensory representations in accordance with moment-to-moment behavioral requirements. These modulations can be studied by varying task demands; however, the tasks employed are often incongruent with the postulated functions of a sensory system, limiting the characterization of the system in relation to natural behaviors. Here we combine domain-specific task manipulations and ultra-high field fMRI to study the nature of top-down modulations. We exploited faces, a visual category underpinned by a complex cortical network, and instructed participants to perform either a stimulus-relevant/domain-specific or a stimulus-irrelevant task in the scanner. We found that 1. perceptual ambiguity (i.e. difficulty of achieving a stable percept) is encoded in top-down modulations from higher-level cortices; 2. the right inferior-temporal lobe is active under challenging conditions and uniquely encodes trial-by-trial variability in face perception.Competing Interest StatementThe authors have declared no competing interest.