The Beneficial Effects of Meprobamate on Delayed Response Performance in the Frontal Monkey

Abstract

Previous studies of antagonistic treatments on delayed response performance by frontal monkeys suffer from a logical flaw in that the treatments may also improve the performance of normal monkeys. In a previous study (Gross and Weiskrantz, 1961) we have shown that meprobamate is without effect on delayed response in normal monkeys, but it does severely depress their discrimination performance. In the current study meprobamate is shown to produce a significant improvement in delayed response in each of three frontal monkeys. Nembutal is also effective. Various interpretations of the results are discussed, the view being favoured that the frontal monkey suffers from an excessive and inappropriately ordered intake of sensory information.

Activity changes following sulcal, but not medial, ablation of the prefrontal cortex of the guinea pig

“…In line with this argument are results showing higher percentages of correct responses in learning tasks in prefrontally lesioned animals when these animals are tested under barbiturates (Wade, 1947;Weiskrantz, Gross, & Baltzer, 1965) or when they participate in learning tasks, in which the animal's responses have been guided by particularly clear structuring of relevant task dimensions (Pohl, 1973;Pribram & Tubbs, 1967;Wagman, 1968).…”

Comparative analysis of prefrontal learning functions in rats, cats, and monkeys.

“…After Jacobsen, this series of investigations was continued by Harlow's group (Campbell & Harlow, 1945;French & Harlow, 1962;Harlow, Davis, Settlage, & Meyer, 1952;Harlow & Settlage, 1948;Leary, Harlow, Settlage, & Greenwood, 1952;Meyer, Harlow, & Settlage, 1951;Warren, Leary, Harlow, & French, 1957) and by Pribram's group (Mishkin & Pribram, 1955Pribram, 1950Pribram, , 1954Pribram, , 1955Pribram, , 1958Pribram, , 1960Pribram, Lim, Poppen, & Bagshaw, 1966;Pribram, Mishkin, Rosvold, & Kaplan, 1952), as well as by others (Blum, 1952;Brush, Mishkin, & Rosvold, 1961;Chow, Blum, & Blum, 1951;Finan, 1939Finan, , 1940Finan, , 1942Malmo, 1942;Orbach, 1956;Orbach & Fischer, 1959;Wade, 1947Wade, , 1952. Individual investigations focused on the effects of variables such as changing the monkey's environment during task performance (Malmo, 1942), long test experience (Campbell & Harlow, 1945), a predelay period (Finan, 1939(Finan, , 1940(Finan, , 1942, and sedatives (Wade, 1947;Weiskrantz, Gross, & Baltzer, 1965). Efforts have also been made to identify subregions that are critical for the deficit (Blum, 1952), to test the relative effects of lobotomy versus lobectomy …”

Differential effects of amphetamine and scopolamine on matching performance of monkeys with lateral frontal lesions.

“…The rationale has been to infer the source of the frontal deficit from the known action of a drug. However, rarely has the effect of a drug on the test performance of normal animals been compared to the drug's effect on frontal animals (Weiskrantz et al, 1965). .…”