Role of haptic cues in motor learning

We introduced haptic cues to the serial reaction time (SRT) task alongside the standard visual cues to explore the relative contributions of haptic and visual cues to motor memory and perceptual memory. Motor learning is a complex process that likely depends on the availability of haptic sensory feedback. Motor learning is also often an implicit process, wherein the learner is not even aware that learning is taking place. The SRT task was devised to study implicit learning. Reaction times (RTs) are reduced with practice even in the absence of explicit learning about a sequence embedded in a train of cues. We adopted an SRT protocol developed by Willingham in 1999 to determine whether haptic cues contribute differently than visual cues to the balance of motor and perceptual learning. Experimental results involving 32 participants showed that sequence learning occurs implicitly with haptic stimuli to much the same extent as visual stimuli. Also, it was revealed that the dependence on motor memory (as opposed to perceptual memory) was greater in the group responding to haptic cues than the group responding to visual cues. Comparing the dependence on motor versus perceptual memory, the haptic group reached marginal significance (p=.09), whereas the visual group difference was not significant (p=.23).