Effects of early undernutrition on motivation and discrimination learning in rats.

Offspring were either adequately nourished or undernourished during the suckling period. They had free access to food from weaning, and were given 2 behavioral tests between 13 and 19 weeks of age. Motivation for water was tested on a variable interval (VI) schedule at 3 levels of deprivation and a test of light-dark discrimination made at 23.5 hr of water deprivation. The results indicated (1) no clear difference in VI response rate, but (2) significant differences in discrimination performance between the 2 groups. A learning ability or certain relevant abilities rather than motivation for water appeared responsible for the difference in discrimination learning.