Stimulus-classification and stimulus-action associations: Effects of repetition learning and durability.

It has been shown that acquired stimulus-response bindings result from at least two types of associations from the stimulus to the task (stimulus-task or stimulus-classification; S-C) and from the stimulus to the motor response (stimulus-response or stimulus-action; S-A). These types of associations have been shown to independently affect behaviour. This finding suggests that they are processed in different pathways or different parts of a pathway at the neural level. Here we test a hypothesis that such associations may be differentially affected by repetition learning and that such effects may be detected by measuring their durability against overwriting. We show that both S-C and S-A associations are in fact strengthened when learning is boosted by increasing repetitions of the primes. However, the results further suggest that associations between stimuli and actions have less durable effects on behaviour and that the durability of S-C and S-A associations is independent of repetition learning. This is an important finding for the understanding of the underlying mechanisms of associative learning and particularly raises the question of which processes may affect flexibility of learning.