Can Rats Acquire an Olfactory Learning Set?

Experimental rats were trained on multiple two-odor discrimination tasks while controls were given repeated sessions on task one and then tested on a novel two-odor task. Experimental rats showed strong positive transfer across problems and approached errorless or near errorless learning. Control rats maintained near-perfect performance on task one, but performed at chance on initial trials when tested with novel odors. Thus, the near errorless terminal performance of experimental rats was a function their having been trained on multiple problems and was not simply the result of eliminating ‘disruptive response tendencies’ (Reid and Morris, 1992). These results support the view that when rats are trained on a series of two-odor discrimination tasks they acquire a strategy or rule that allows them to solve new problems with few or no errors.