The compensatory role of food-motivation in the maze learning performance of lactationally undernourished rats.

To test the hypothesis that the motivational effects of neonatal undernutrition might conceal the detrimental effects on learning, we tested previously undernourished and normally nourished Sprague-Dawley rats on learning of a novel maze pattern under either latent learning (nonappetitive) or food-motivated conditions. Under the nonappetitive conditions, the previously undernourished rats learned significantly less than the normal controls, but when motivated for food, the undernourished rats performed as well as the controls. When learning performance measures are sensitive to motivation, differential motivation between undernourished and normal subjects must be controlled or eliminated.