Impairments on locomotor task involving spatial opposition between cue and reward in frontally ablated monkeys.

Abstract

In a previous experiment (St~pieli et al. 1966) dogs and cats were trained to respond to an auditory cue by walking to a food tray located in the direction opposite to thlat of the source of the cue or in a neutral place at a distance of 2 m from it. This habit became severely disturbed following bilateral ablation of medial precruciate cortex (which was originally regarded as a part of the premotor area) and the animals exhibited marked magneto-reactions during the early post-operative period which only declined gradually during post-operative training. The magneto reaction which was expressed by the subject's approach to the cue, standing in front of it during its activation and often touching it with the nose, could not be elicited by removal of other cortical areas of the frontal lobes, including the proreal areas. Since ablation of these structures have been found to result in severe impairments by dogs on tasks of delayed response (Eawicka et al. 1966) it (appears that two distinct patterns of behavioral impairments can be related to these two cortical areas in the dogs frontal lobes. In monkeys impairments on delayed response tasks are clearly elicited by ablation of dorsolateral prefrontal cortex, and especially the segment of sulcus principalis (Mishkin 1957). The aim of the present investigation is to further explore homologous organization of frontal cortex in dogs and monkeys by training of monkeys on locomotor tasks involving spatial opposition between location of