The effect of cortical lesions on emotional and regressive behavior in the rat. I. Emotional behavior.

Abstract

A. INTRODUCTIONPhysiological, clinical and pathological observations point to the diencephalon as that part of the central nervous system in which is located the neural organization for the expression of certain emotional reactions. The evidence likewise indicates that the cerebral cortex normally functions in such a manner as to dominate these expressions which are integrated at the lower levels. The cortex can function not only in a negative way by preventing the occurrence of the expressions of these emotional states, but it can also greatly increase the number of situations which are capable of acting as emotional stimuli.The theory of the inhibitory functioning of the cortex in relation to subcortically organized mechanisms, early advanced by Hughlings Jackson (25) and later elaborated by Head (22,23) gets most of its support in connection with emotional expression from a group of studies on sham rage. In the majority of these studies lesions have been produced at various levels in the nervous system of animals (cats and dogs) and a delimitation attempted of the area which must be present for the appearance of sham rage of maximal intensity.* Standard errors of coefficients are used throughout this study.

The cerebral cortex and locomotor activity in rats.

“…The temporary emotional changes of the first week were undoubtedly associated with general operative shock and healing of the wound. This absence of increased postoperative savageness confirms Beach's observations and also those of Beil and Kelley (3), that no emotional disturbances were found in animals subjected to removal of varying amounts and portions of the cerebral cortex.…”

Temperament: a survey of animal studies.

“…Similar correlations for three groups of rats have been found by Biel and O'Kelly (9). Group I consisted of rats with cortical lesions; Group II were operated upon, but no lesions were made; and Group III were normal rats.…”

“…In Stone's study (45) the following groups of rats were compared: (a) offspring of wild rats, (b) half-breeds (wild X albino), (c) quarter-breeds (half-breed X albino), (d) pure albinos, and (e) trapped wild rats which had been confined to cages and had been givensystematichandlingfor six months. 9 Stone madenoattempt to differentiate between wildness and savageness. He rated a rat on a scale from 0 to 3 for each of 11 reactions for 10 trials in three situations.…”

“…Hall (18) employed a circular field, seven feet in diameter, because it offers no corners into which the animal can retreat. As standardized by Hall and used in a number of studies (2,3,4,5,6,7,9,28,30), the field is well lighted by a light hanging directly over the center of the enclosure.6. Cage-Emergence.…”

A biological theory of reinforcement.

“…The effects of decortication on speciescharacteristic motor sequences are quite different. The elicitation and habituation of locomotor activity in a novel surround survives extensive cortical lesions (Biel & O'Kelly, 1940;Glickman, Sroges, & Hunt, 1964), as does hoarding behavior (Stamm, 1953), although cingulate invasion in particular has serious quantitative effects upon the latter (Stamm, 1954). The complex sequences involved in sexual behavior survive lesions of any part of the cortex in both male and female rats (Beach, 1940(Beach, , 1944a.…”