Details

Autor(en) / Beteiligte

• Mitchell, Jude F.
• Sundberg, Kristy A.
• Reynolds, John H.

Titel

Spatial Attention Decorrelates Intrinsic Activity Fluctuations in Macaque Area V4

Ist Teil von

• Neuron (Cambridge, Mass.), 2009-09, Vol.63 (6), p.879-888

Ort / Verlag

United States: Elsevier Inc

Erscheinungsjahr

2009

Link zum Volltext

Quelle

Access via ScienceDirect (Elsevier)

Beschreibungen/Notizen

• 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.