Implicit learning

As we practice tasks, even simple ones, our performance becomes more fluent and less effortful.  Understanding how performing a task changes the underlying operations so that it is performed more efficiently on subsequent attempts is essential to developing theories of human behavior.  We have examined learning processes using a variety of tasks, including the serial reaction time task and the chord learning task.  In the latter, participants are presented with multiple, simultaneously appearing stimuli, which indicate that they should produce multiple, simultaneous responses.  Critically, combinations of responses that have been practiced are performed more quickly and accurately than novel combinations, even when the individual stimuli and responses, considered separately, have been performed the same number of times.  Because this practice benefit is sensitive to manipulations of both the stimuli and responses, the task appears to tap associate learning involving central representations that incorporate input and output information.  Moreover, the conceptual representation of responses can affect the ability to form associations between them.  If responses are seen as conceptually-related, that is, they are performed in the service of a common goal, then they will be more readily associated than responses that are conceptualized as unrelated. 

We have also investigated the roles that positive and negative feedback play in the formation of these associations.  Our findings indicate that participants can benefit from reward even when awareness of which combinations are rewarded remained low. Thus, the benefit of reward does not appear to relate to changes in motivation.  The benefit is observed even when multiple rewarded and unrewarded combinations shared a single response. We conclude that incidental learning processes are affected by reward in such a way to allow for the specific strengthening of rewarded associations.

Representative Papers