ABSTRACT
I have vivid memories of reading, many, many years ago, two quirky little studies that piqued my interest then, and have repeatedly bubbled up into consciousness in such contexts as children’s parties, and while looking at myself for some reason or other, in the mirror. The experiments were trivial, downright silly, you may say, but the theoretical implications may be profound. I have also often thought of them as possible research projects for students. One of the studies asked why, as many party-going children know, we cannot simultaneously tap our heads with the flat of one hand while with the other performing circular, rotary motions on the stomach, a different movement in another plane. I won’t waste much more time on this study, except to say that decades later I devised a complex, computerised system to measure our ability to rotate the two hands, in or out of phase with each other, and in two modes, mirror symmetrical (perhaps left hand clockwise, right hand anticlockwise) or congruent (that is both in the same direction). Importantly, we found theoretically and clinically interesting differences in the abilities of various patient groups with damage to the motor systems of their brains.
