The effects of inferior temporal and dorsolateral frontal lesions on serial-order behavior and visual imagery in monkeys

Abstract

Four monkeys were trained preoperatively on a serial-order task to respond to a set of five visual stimuli in a fixed sequence independent of their location. They were then given a test of visual imagery in which only two of the five stimuli appeared at a time, and the animals were required to respond to them in the order in which they appeared in the original sequence. The monkeys then received bilateral lesions of either inferior temporal cortex or dorsolateral frontal cortex. Dorsolateral frontal lesions had no effect on either serial-order behavior or visual imagery. In contrast, inferior temporal lesions severely impaired serial-order behavior. Once the serial-order task was relearned, however, the inferior temporal animals were completely normal on the test of visual imagery.