In the visuomotor mental rotation (VMR) task, participants point to a location that deviates from a visual target by a predetermined angle. A seminal investigation of the VMR task reported a linear increase in reaction time (RT) as a function of increasing angle, for 5°, 10°, 15°, 35°, 70°, 105°, and 140° (Georgopoulos and Massey, 1987). This finding led to the development of the mental rotation model (MRM) and the assertion that response preparation is mediated via the imagined rotation of a movement vector. To determine if the MRM can be extrapolated to perceptually familiar angles (e.g.; 90° and 180°) within a range of equally spaced angles, we evaluated two independent sets of angles: 5°, 10°, 15°, 35°, 70°, 105°, and 140° (experiment one) and 30°, 60°, 90°, 120°, 150°, 180°, and 210° (experiment two). Consistent with the MRM, experiment one revealed a linear increase in RT as a function of increasing angle; however, a non-linear relation was revealed for experiment two. RTs were fastest for 180°, followed by 30°, 90°, 60°, 150°, 210°, and 120°. Such results demonstrate that response preparation was not uniquely mediated via a mental rotation process. Instead, the present work provides evidence of a temporally demanding and cognitively mediated response substitution process, wherein the computational demands of response preparation are determined by the complexity of the sensorimotor transformations mediating the response.
All Science Journal Classification (ASJC) codes
- Molecular Biology
- Clinical Neurology
- Developmental Biology