Published online by Cambridge University Press: 01 February 2004
Understanding neural anatomy and physiology depends on first understanding the behaviour being mediated. Glover, in his review of earlier work suggesting various dichotomies in visual processing, shows how there is a tendency to oversimplification if this approach is ignored. His own new proposals demonstrate the advantages of allowing function to drive anatomical analysis. Nevertheless, the new planning–control dichotomy he proposes, though a valuable advance, is itself an oversimplification of what must be a multi-channel system.
1. It is perhaps worth noting that it seems unlikely that nonhuman primates do not have some element of planning in their motor control and that neural mechanisms in the frontal lobes, particularly the frontal eyefields, have been suggested in this context (Collin et al. 1982; Latto 1986).
2. The first usage of this useful term that I can find is Mesulam (1985; 1989).
3. The fact that English has a specific part of speech, the comparative inflection of the adjective, to identify a binary category (higher, lower, etc.) raises the possibility that the tendency to form binary subdivisions is a fundamental process in human thought. Maybe, as with some primitive counting systems (“one, two, many”), two subdivisions are as many specific categories as we can easily cope with.