Abstract
Although our mental functions can only be expressed in the world through our actions, historically, there is little work linking cognitive and motor processes. Previous studies have demonstrated that visual mental rotation and visuomotor rotation have similar processing rates and brain regions involved in (Pellizzer & Georgopoulos, 1993; Georgopoulos et al., 1989). However, as correlational studies, these cannot fully determine whether a common mechanism drives motor and mental rotation. To address this question more directly, we investigated whether training in visuomotor rotation can improve performance in visual mental rotation and vice versa. In the visuomotor rotation task, participants were required to reach to a target, while the cursor feedback was rotated 45º to force movement adaptation. In the visual mental rotation task, participants were asked to decide whether a letter (e.g., R) in different rotation angles was normal or mirror-reversed. We found that after the visuomotor rotation training session, participants became faster in visual mental rotation compared to before. In turn, we also observed that the learning rate of visuomotor adaptation was improved after a mental rotation training session. We also conducted control experiments in which participants were trained on a motor task without requiring rotational adaptation (i.e., a direct reach and a sequential reaction time task) and a letter color discrimination task without requiring the rotation judgment. Training on these tasks resulted in a significantly weaker transfer to their counterparts. Thus, we ruled out that some simple motor and perceptual transfer led the observed reciprocal improvement. What is remarkable about this reciprocal plasticity is that these two tasks are very different in terms of perceptual input and motor response. Nevertheless, transfer occurred. Could this mean that the operation of “rotation” itself is a primitive for perception and action that has yet to be fully identified or understood?