Functional specialization within the dorsolateral frontal cortex for serial order memory.

Monkeys with lesions restricted to two anatomically distinct regions of the dorsolateral frontal cortex were tested on a novel task that was developed to assess memory for the order of occurrence of stimuli. Monkeys with bilateral lesions of the mid-dorsolateral frontal cortex (cytoarchitectonic areas 46 and 9) were severely impaired, whereas monkeys with lesions of the posterior region of the dorsolateral frontal cortex (area 8 and rostral area 6) performed as well as the normal control animals. These results show that the primate mid-dorsolateral frontal cortex is a critical component of a neural circuit underlying the monitoring of the serial order of stimuli.