PT  - JOURNAL ARTICLE
AU  - Connor, Charles E.
AU  - Preddie, Dean C.
AU  - Gallant, Jack L.
AU  - Van Essen, David C.
TI  - Spatial Attention Effects in Macaque Area V4
AID  - 10.1523/JNEUROSCI.17-09-03201.1997
DP  - 1997 May 01
TA  - The Journal of Neuroscience
PG  - 3201--3214
VI  - 17
IP  - 9
4099  - http://www.jneurosci.org/content/17/9/3201.short
4100  - http://www.jneurosci.org/content/17/9/3201.full
SO  - J. Neurosci.1997 May 01; 17
AB  - Focal visual attention typically produces enhanced perceptual processing at the psychological level and relatively stronger neural responses at the physiological level. A longstanding mechanistic question is whether these attentional effects pertain specifically to the attended (target) object or to the region of space it occupies. We show here that attentional response enhancement in macaque area V4 extends to behaviorally irrelevant objects in the vicinity of the target object, indicating that focal attention has a strong spatial component at the physiological level. In addition, we find that spatial attention effects typically show a striking directional asymmetry. The direction of the asymmetry varies between cells, so that some cells respond best when attention is directed to the left of the stimulus, some when attention is directed to the right, etc. Thus, attention involves not only enhanced responses to behavioral targets but also a complex modulation of responses to other stimuli in the surrounding visual space.