Effects of Drive Level on the Type and Degree of Cue Control in Rats

Abstract

58 hooded rats were presented with a discrimination task involving redundant, relevant cues of orientation (vertical vs horizontal) and brightness (black vs white). Two experiments systematically evaluated the range and degree of cue control as a function of drive level (high or low), dimensional saliency, or the interaction of the two. Contrary to past research and prominent discrimination learning models: (1) low drive did not favor multiple-cue control, (2) the most salient cue did not reduce the control of the least salient cue, and (3) no interaction between motivational level and type of cue control was found. Compared with low-drive, high-drive subjects consistently showed more cue control in spite of faster acquisition and fewer errors to criterion. Differences between these results and those which did report drive level and/or dimensional saliency effects were attributed to important procedural variations or the choice of experimental subjects.