No abstract

Four groups, Young Males, Young Females, Aged Males and Aged Females, were run in a discrimination conditioning paradigm with a variety of autonomic and central measures. This paper deals primarily with Electro-Dermal Responses. The findings indicate that in all measures the Young Males and Young Females show the best discriminated conditioning, followed by Aged Females and AgedMales.In the GSP there are hints that the negative wave of the response might be related to the orienting phenomena whereas the positive wave is what becomes discriminately conditioned in the experiment.

No abstract

The effects of melanocyte-stimulating hormone (MSH) on attention and memory in the rat were examined under conditions of constant darkness and constant illumination. After acquiring a brightness discrimination problem, half of the rats were given a reversal task and half a memory task. Rats treated with MSH and those tested in the dark performed the reversal task significantly faster than rats tested under constant illumination. Differences in memory were detected among the groups, however, not to a statistically significant extent. The results were interpreted to suggest that increased MSH levels lead to increased awareness of the environment in the rat and that functionally equivalent behavior among other species may derive from similar neuroendocrine substrates.