Figure 1. Schematic representation of how frequencies are represented across the horizontal dimension of cortex. Similar to playing the keys sequentially on a piano, auditory cortex represents lower to higher frequencies in a precise order. Thus the auditory cortex is often referred to as being ‘tontotopically’ organized. The vertical dimension represents columns of cells devoted to the processing of a given frequency, thus the frequency representation changes in the horizontal, but not the vertical, dimension of cortex.

Figure 2. A lateral view of a macaque monkey brain and face indicating the region in the brain that would normally represent the hand and then deafferented, which is labelled the deafferented zone and indicated on the view of the brain. Over time the deafferented region comes to represent the portion of the lateral face and chin indicated as a grey area on the face. The face has been made transparent so that the underlying brain is visible. The view shown is for illustrative simplicity; in reality the left hemisphere of the brain would represent the right lateral.

Figure 3. Right lateral view of the head and face with the underlying brain shown. The grey area on the brain indicates the normal location of the hand representation which was deafferented. Interestingly, touch to the region of the head and face that is now represented in the grey area (cf. Figure 2) elicits sensation to the digits 1(thumb) to 5 (little finger) of the hand and palm. Other conventions are as in Figure 2.