Incidental sequence learning in a motion coherence discrimination task: How response learning affects perception.

The serial reaction time task (SRTT) is a standard task used to investigate incidental sequence learning. Whereas incidental learning of motor sequences is well-established, few and disputed results support learning of perceptual sequences. Here we adapt a motion coherence discrimination task (Newsome & Paré, 1988) to the sequence learning paradigm. The new task has 2 advantages: (a) the stimulus is presented at fixation, thereby obviating overt eye movements, and (b) by varying coherence a perceptual threshold measure is available in addition to the performance measure of RT. Results from 3 experiments show that action relevance of the sequence is necessary for sequence learning to occur, that the amount of sequence knowledge varies with the ease of encoding the motor sequence, and that sequence knowledge, once acquired, has the ability to modify perceptual thresholds.