MNEMONIC RESPONSES OF SINGLE UNITS RECORDED FROM MONKEY INFEROTEMPORAL CORTEX, ACCESSED VIA TRANSCOMMISSURAL VERSUS DIRECT PATHWAYS - A DISSOCIATION BETWEEN UNIT-ACTIVITY AND BEHAVIOR
S. Sobotka et Jl. Ringo, MNEMONIC RESPONSES OF SINGLE UNITS RECORDED FROM MONKEY INFEROTEMPORAL CORTEX, ACCESSED VIA TRANSCOMMISSURAL VERSUS DIRECT PATHWAYS - A DISSOCIATION BETWEEN UNIT-ACTIVITY AND BEHAVIOR, The Journal of neuroscience, 16(13), 1996, pp. 4222-4230
Three macaques were trained on a task in which a sequence of single vi
sual images was presented serially, and the monkeys signaled whether t
he image was a new or a repeated one. The optic chiasm and splenium of
the corpus callosum were transected, leaving the anterior commissure
as the only path for cortical interhemispheric transfer, Images were p
resented to only one eye at a time. Re-presentations of images to the
same eye were recognized correctly in >95% of trials. A robust stimulu
s-specific adaptation (i.e., a reduced response to a repeated image) w
as seen in the population of single units recorded from inferotemporal
cortex during these same trials. When an interhemispheric transfer wa
s demanded of the animals (i.e., the re-presentation was made to the o
ther eye), recognition performance was somewhat reduced, to 86% correc
t. Interestingly, in this situation the stimulus-specific adaptation d
isappeared completely, The disappearance occurred regardless of whethe
r the transfer direction was from the hemisphere ipsilateral to the re
cording site to the hemisphere contralateral to the recording site, or
vice versa. Thus, stimulus-specific adaptation in inferotemporal cort
ex units is not required for recognition.