Walter Isaac

Effect of Illumination and D-Amphetamine on the Activity of the Rhesus Macaque

The activity of the Rhesus macaque was measured under three levels of ambient illumination and three dosages of d-amphetamine. Analysis of variance indicated that activity increases as a function of increasing level of illumination and decreases as a function of increasing dosages of amphetamine. The interaction effect was nonsignificant.

ROLE OF STIMULATION AND TIME IN THE EFFECTS OF SPACED OCCIPITAL ABLATIONS

42 albino rats were trained preoperatively to make an avoidance response to a change in illumination. The occipital lobes were serially ablated. The interval between ablations and the sensory stimulation conditions during the interoperative interval were varied. Following the second operation retention of the original response was measured. Performance was found to be related to both the length of the interoperative interval and the existing stimulus conditions during the interval.

Frontal lesions and illumination effects upon the activity of the albino rat

Abstract Cage activity under conditions of light and dark was studied in normal rats, rats with frontal cortical ablations, and rats with deep ablation of the frontal poles. The effects of the lesions were significant and the effects of illumination varied among the three groups of subjects.

Pharmacological modification of the effects of spaced occipital ablations

SummaryRetention of an avoidance response made to the onset of a change in illumination was measured following temporally spaced bilateral ablation of the occipital cortex of the rat. Twelve days were allowed to pass between the ablation of cortex of the two hemispheres. Post-operative retention was superior when the inter-operative interval was spent in the light and noise, except when paired with chronic administration of phenobarbital (30 mg/kg/day). Post-operative retention was minimized when the interoperative interval was spent in dark and quiet, except when paired with chronic administration of d-amphetamine (2 mg/kg/ day).

The influence of illumination upon the temporal patterning of responses in squirrel and owl monkeys

The temporal patterning of responses within a fixed-interval reinforcement situation was studied in the nocturnal Owl monkey and the diurnal Squirrel monkey. The response rates of both groups were found to vary, but in opposite directions, with illumination conditions, but no evidence of temporal patterning was observed in the Owl monkeys.

Occipital ablation and retention of a visual conditioned avoidance response in the rat

Retention of a cooperatively established light contingent avoidance response following bilateral occipital ablation was studied. The two variables of interest, level of preoperative training and duration of postoperative recovery period, had a significant effect upon postoperative retention.

EFFECTS OF SODIUM PENTOBARBITAL AND D-AMPHETAMINE ON LATENCY OF THE ESCAPE RESPONSE IN THE RAT

It has been demonstrated that the reticular formation of the brainstem is the principal site of action of certain drugs. Killam and Killam (1958) reported that 10 mg./kg. of sodium pentobarbital in cats blocked the cortical EEG arousal from electrical stimulation of the reticular formation and thalamus. It also depressed responses in the reticular formation to stimulation of the sciatic nerve and to intra-reticular stimulation. Bradley ( 1958) reported that the intravenous administration of 2 to 5 mg./kg. of dl-amphetamine to the conscious cat produced low amplitude, fast activity in the EEG, as well as behavioral alertness and hyperactivity. He also showed that the effects of this drug are susceptible to mid-brain transection in both cats and monkeys. Sodium pentobarbital and d-amphetamine seem to affect the brainstem reticular formation in opposite directions. Because of the implication that the activity of this system might have for the understanding of behavior the present study was designed to evaluate the effects of these drugs on the escape response in the rat.

A Reply to Dr. Leuba's Comments

The comments of Dr. Leuba seem directed at a portion of a sentence in the summary of my paper. I believe that it was made quite clear in the Introduction, as well as the first sentence of the Summary, that the statement to which he referred would be valid only to the extent that the stated criteria of a drive are adequate. While he did not refer to my criteria of a drive, he launched an attack against current drive states conceptualized at the level of a n intervening variable. H e argued that all drives should be firmly based on a biological tissue need. Thus, he would restrict drive to the conceptual level of a hypothetical construct. However, his concluding paragraph suggests a preference for the investigation of functional relationships without regard to concepts a t either the intervening variable or hypothetical construct level. Consequently, I am not certain of Dr. Leubas position and am not sure with which aspect of my paper he disagrees. The use of intervening variables in psychology has been adequately defended elsewhere. The notion of an optimal level of arousal which the animal will strive to maintain is not original with me, or my paper. It would seem that Dr. Leubas quarrel is with contemporary psychology in general, rather than my paper in particular.

Effects of Illumination and White Noise on the Rate of Electrical Self-Stimulation of the Brain in Rats

A consistency in the effects of food deprivation and amphetamine administration on both gross locomotor activity and electrical self-stimulation of the brain (ESSB) is noted. The effects of sensory conditions on ESSB were investigated. Rats were trained to press a bar for rewarding brain stimulation. When Ss had stabilized, they were tested in a complete factorial design composed of four levels of illumination and two levels of noise. It was found that Ss pressed more under the medium illumination condition than under any other level of illumination, while white noise had no significant effects. Since rats are more active in the dark than in the light, it is concluded that illumination has unlike effects on activity and rate of ESSB.