C. Constantinidis et Ma. Steinmetz, Neuronal responses in area 7a to multiple stimulus displays: II. Responsesare suppressed at the cued location, CEREB CORT, 11(7), 2001, pp. 592-597
Everyday visual scenes contain a variety of stimuli that vary in their sign
ificance. The companion paper demonstrates that neurons in the posterior pa
rietal cortex (PPC) are capable of encoding the spatial locations of the sa
lient stimulus in multiple stimulus scenes. The present experiment sought t
o address how neuronal responses to stimuli appearing in the receptive fiel
d ace modulated after attention has been drawn to one of multiple stimuli i
n a visual scene. We recorded from area 7a of the PPC in monkeys trained to
do a spatial version of a match-to-sample task. The results show that neur
onal responses are greatly suppressed when stimuli appear at previously att
ended locations. No reduction in responsiveness is observed for locations w
here stimuli had previously appeared but did not draw attention. These resu
lts support the hypothesis that area 7a has a role in redirecting attention
to stimuli appearing at novel, unattended locations.