The medial frontal cortex and temporal memory: tests using spontaneous exploratory behaviour in the rat.

Evidence from several sources indicates that the frontal cortex is involved in memory involving time, or temporal memory, and in behavioral sequencing. Rats were presented with two familiar objects and the amount of exploration directed at each was recorded. Subjects directed more exploration at the object encountered further ago in the past, even though the two objects differed by only 1 h. After bilateral medial frontal cortex lesion, animals did not differentiate between old and recent objects. Performance on an object recognition test (novel versus familiar objects) that also used exploration time did not change as a result of the medial frontal cortex lesions.