The primate frontal cortex: progress report 1975.

Studies of the functions of the cortex anterior to the motor regions of the brain have a venerable history. In non-human primates resections of this frontal eugranular cortex have been known for almost half a century to produce a very specific deficit in tasks characterized by the interposition of a delay between the occasion when a behavioral response is cued and when that response can be carried out. In man the procedure of frontal lobotomy or leukotomy and its various derivatives forms a chapter in the treatment of mental illness which has been variously evaluated as worthy of a Nobel prize and as morally degenerate. Further, the relationship between the results of the laboratory experiments on non-human primates and those obtained in the psychosurgical clinic has never become clear. These deficiencies in our understanding of the functions of the primate polar frontal cortex are not due to neglect. Professor Konorski's efforts are well known and much appreciated by investigators the world over who have diligently pursued the problem. The results of their work can be found in two recent publications: The Jablonna Symposium on the Frontal Granular Cortex edited by Konorski, Teuber and Zerniclti (1972) and The Psychophysiology of the Frontal Lobes, edited by Luria and myself (1973). Here, therefore, it is more fitting that an attempt be made to briefly review the highlights of the recent additions t o this vast body of research; to report some as yet unpublished work which has bearing on our understanding of the frontal lobe problem; and to attempt to formulate a useful hypothesis about frontal lobe function based on these data.