Abstract
Visual long-term memory is known to play important role in visuo-motor learning. In a classical visuo-motor learning task, the serial reaction time (SRT) task, the participants first learn a fixed visuo-motor sequence via repetitions for multiple blocks, and then was suddenly interrupted by a block of random sequence, followed by a last block of re-appearance of the learned sequence. A typical finding is that response time becomes faster as sequence has been learned, slows down when the random sequence interrupted the learning, and speeds back up as the learned sequence re-appears. However, whether this response pattern reflects motor priming or the guidance of visual long-term memory on attention remains unclear. To examine how visual long-term memory and motor priming affect various learning effects in SRT, we measured pre-stimulus eye fixation patterns to determine whether subjects made an anticipatory eye movement towards the target location. We found that subjects increasingly made a correct anticipatory fixation as they learned the sequence and that this was highly correlated to decreasing response times. Moreover, when the random sequence was presented after these repetitions, the cost of switching to a new sequence template was highly correlated between the increased errors in eye anticipation and the slow-down of motor response time. Lastly, the recovery of long-term memory pattern when the old sequence reappeared was similar in eye and motor patterns, in that participant who regained better eye anticipation of the old sequence also showed a shorter response time in this last block. Collectively, our study suggested that visual long-term memory guides both overt attentional selection and motor priming that together produce performance benefits in the SRT task.