Visual representations are dominated by intrinsic fluctuations correlated between areas

Intrinsic cortical dynamics are thought to underlie trial-to-trial variability of visually evoked responses in animal models. Understanding their function in the context of sensory processing and representation is a major current challenge. Here we report that intrinsic cortical dynamics strongly af...

Full description

Saved in:
Bibliographic Details
Published in:NeuroImage (Orlando, Fla.) Fla.), 2015-07, Vol.114, p.275-286
Main Authors: Henriksson, Linda, Khaligh-Razavi, Seyed-Mahdi, Kay, Kendrick, Kriegeskorte, Nikolaus
Format: Article
Language:English
Subjects:
Brain Mapping - methods
Brain research
Functional MRI
Humans
Image Processing, Computer-Assisted
Intrinsic dynamics
Magnetic Resonance Imaging - methods
Natural images
NMR
Noise
Nuclear magnetic resonance
Pattern information
Photic Stimulation
Representational similarity
Studies
Visual cortex
Visual Cortex - physiology
Visual Perception - physiology
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Intrinsic cortical dynamics are thought to underlie trial-to-trial variability of visually evoked responses in animal models. Understanding their function in the context of sensory processing and representation is a major current challenge. Here we report that intrinsic cortical dynamics strongly affect the representational geometry of a brain region, as reflected in response-pattern dissimilarities, and exaggerate the similarity of representations between brain regions. We characterized the representations in several human visual areas by representational dissimilarity matrices (RDMs) constructed from fMRI response-patterns for natural image stimuli. The RDMs of different visual areas were highly similar when the response-patterns were estimated on the basis of the same trials (sharing intrinsic cortical dynamics), and quite distinct when patterns were estimated on the basis of separate trials (sharing only the stimulus-driven component). We show that the greater similarity of the representational geometries can be explained by coherent fluctuations of regional-mean activation within visual cortex, reflecting intrinsic dynamics. Using separate trials to study stimulus-driven representations revealed clearer distinctions between the representational geometries: a Gabor wavelet pyramid model explained representational geometry in visual areas V1–3 and a categorical animate–inanimate model in the object-responsive lateral occipital cortex.
ISSN:1053-8119
1095-9572
DOI:10.1016/j.neuroimage.2015.04.026