Effects of one-stage and serial ablations of the middle third of sulcus principalis on delayed alternation performance in monkeys.

Recovery of a spatial delayed alternation habit following partial frontal lesions was investigated in mature rhesus monkeys. All animals subjected to serial ablation of the middle third of sulcus principalis were found to be capable of reacquiring preoperative levels of performance on the task. However, one-stage removal of the mid-principalis region resulted in both more severe and more protracted impairments than were evident after serial surgery. These results in conjunction with previous findings suggest that recovery following serially induced neurological insult may be dependent upon the integrity of neural tissue adjacent to the locus of injury.