Table 1.

Trials and errors to criterion

	Learning		Relearning
	T	E	T	E
MDm-1	360	98	0	0
MDm-2	180	72	0	0
MDm-3	420	117	120	25
Mean	320.0	95.6	40.0	8.3
NA-1	240	87	0	0
NA-2	600	166	240	46
NA-3	480	166	0	0
NA-4	540	135	120	17
Mean	465.0	138.5	90.0	15.8
CON-1	360	116	0	0
CON-2	2160	489	420	73
CON-3	720	182	0	0
CON-4*	1980	585	480	75
Mean	1305.0	343.0	225.0	37.0

Trials (T) and errors (E) to acquire 60 visual object discrimination problems before surgery (learning) that completed a crossed surgical disconnection of the amygdala plus PFo with either the medial portion of the MDm or the NA and to relearn the same problems after the disconnection had been completed (relearning). Prior to the present study, all monkeys in the two experimental groups had sustained unilateral lesions of the amygdala and PFo in one hemisphere (left or right). MDm-1 to MDm-3: monkeys designated to receive crossed disconnection of the amygdala plus PFo × MDm; NA-1 to NA-4: monkeys designated to receive crossed disconnection of the amygdala plus PFo × NA; CON-1 to CON-3: unoperated controls; CON-4*: operated control with partial section of the corpus callosum.