Spatial attention decorrelates intrinsic activity fluctuations in macaque area V4.

Full Abstract

Attention typically amplifies neuronal responses evoked by task-relevant stimuli while attenuating responses to task-irrelevant distracters. In this context, visual distracters constitute an external source of noise that is diminished to improve attended signal quality. Activity that is internal to the cortex itself, stimulus-independent ongoing correlated fluctuations in firing, might also act as task-irrelevant noise. To examine this, we recorded from area V4 of macaques performing an attention-demanding task. The firing of neurons to identically repeated stimuli was highly variable. Much of this variability originates from ongoing low-frequency (<5 Hz) fluctuations in rate correlated across the neuronal population. When attention is directed to a stimulus inside a neuron's receptive field, these correlated fluctuations in rate are reduced. This attention-dependent reduction of ongoing cortical activity improves the signal-to-noise ratio of pooled neural signals substantially more than attention-dependent increases in firing rate.

Author information

Author/s: Mitchell, Jude F (JF); Sundberg, Kristy A (KA); Reynolds, John H (JH);

Affiliation: Systems Neurobiology Lab, The Salk Institute, La Jolla, CA 92037-1099, USA.

Grants: EY016161 (Agency:NEI NIH HHS)

Journal and publication information

Publication Type: Journal Article; Research Support, N.I.H., Extramural; Research Support, U.S. Gov't, Non-P.H.S.

Journal: Neuron (Neuron), published in United States. (Language: eng)

Reference: 2009-Sep; vol 63 (issue 6) : pp 879-88

Dates: Created 2009/09/25; Completed 2009/10/09; Revised 2009/10/22;

PMID: 19778515, status: MEDLINE (last retrieval date: 10/23/2009, IMS Date: )

Sourced from the National Library of Medicine. Abstract text and other information may be subject to copyright.

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