Clarifying the role of higher-level cortices in resolving perceptual ambiguity using ultra high field fMRI.
Neuroimage
; 227: 117654, 2021 02 15.
Article
in En
| MEDLINE
| ID: mdl-33333319
ABSTRACT
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.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Attention
/
Visual Perception
/
Brain Mapping
/
Magnetic Resonance Imaging
/
Cerebral Cortex
Limits:
Adolescent
/
Adult
/
Female
/
Humans
/
Male
Language:
En
Journal:
Neuroimage
Journal subject:
DIAGNOSTICO POR IMAGEM
Year:
2021
Document type:
Article