Effect of task complexity on ipsilateral motor response programming to physically presented and imagined stimuli

It is unclear whether task representation generated in imagery simulates performance demands in reacting to stimuli. This study investigated whether perceptual and motor control processes used to react to unpredictable stimuli and initiate an ipsilateral movement were replicated during imagery. Fifty-nine undergraduate students ( Mage = 27.01 years, SD = 8.30) completed 30 simple, two-choice congruent and two-choice incongruent ipsilateral finger–foot movement trials in response to a physically presented or imagined stimulus. The results appear to indicate that participants were reacting to imagined and actual stimuli, as the ipsilateral finger–foot programming rule was maintained and reaction time initially slowed as task difficulty increased. These findings support theoretical similarities between imagery and physical performance of reaction tasks, with imagers generating and reacting to unpredictable stimuli. Slower imagery performance than physical performance on the two-choice incongruent task may indicate that task complexity is limited during imagery. Variation in results between the imagery and physical conditions potentially supports that imagers were able to react to the imagined stimulus. However, exploratory processes used to react to stimuli were not replicated during imagery. The present findings have potentially significant implications for the functional and applied use of imagery for skill acquisition.