[Inferotemporal neuron activities of monkey during Konorski's task (author's transl)]

In order to search inferotemporal (IT) neuron activities related to processes of visual discrimination and visual short-term memory, the monkeys were trained to do so called Konorski's task. In the task, the monkey was seated in a primate chair and a pair of color stimuli (red or green) was presented from the same two colored light-emitting-diode (LED) before and after a fixed delay interval of 1-5 sec. The monkey was rewarded for pressing one of two levers when two stimuli were the same in color, and the other side when two stimuli were different. A total of 101 neurons were recorded from the anterior IT (between A3-A15). About 80% of recorded neurons activated by LED and about 60% of them showed different discharge rates to different colors (color selectivity). About 80% of color selective neurons showed stronger responses to the second visual stimuli than the first stimuli. These color selective neurons were recorded from the posterior part of the anterior IT (between A3-A10). No color dependent activities were observed during delay period. The data suggested that the IT neurons were related to a process of visual discrimination so that a physically identical stimulus which had a different meaning in the behavioral context would be differentiated.