Operant Level and Light-Contingent Bar Presses as a Function of Age and Deprivation

Abstract

Young and senescent male albino rats ( Ns = 40) were run in operant level and light-contingent bar-press tests. Food deprived rats made more presses than nondeprived rats and the increase was similar at each age level for all tests. During light-contingent bar-press tests the bar which produced a 3-sec. burst of light was preferred by all groups. Senescent rats made fewer bar presses than young rats during all tests. In the evaluation of extinction data, young rats would be expected to make more responses than senescent rats due to the higher base operant level of young rats, although differential age effects for secondary reward can be evaluated directly by comparisons of bar preferences in a 2-bar Skinner box.