Figure 8

Reorganization of the affected (left) hemisphere (A) and nonaffected (right) hemisphere (B) after stroke followed by therapy or no therapy. In each panel, histograms of the cells' preferred directions are shown (1) before stroke, (2) after stroke with 500 free choice trials, and (3) after 3,000 free choice trials or (4) after 1,000 forced used training trials and subsequent 2,000 free choice trials. The gray area in (A.2) shows the lesion site. Before the lesion, the left hemisphere contains more neurons with preferred directions in the right workspace, and the right hemisphere contains more neurons for the left workspace because of the bias for workspace preference. Just after lesion, the left hemisphere is affected. If no therapy follows, the size of the affected range increases, and the number of neurons for the fourth quadrant increases in the affected hemisphere (maladaptation) and in the first quadrant in the nonaffected hemispheres (A.3). On the contrary, the number of neurons for the first quadrant in the right hemisphere increases due to compensation. After therapy (1,000 forced use trials followed by 2,000 free choice trials), however, the distributions of directions are similar to the prelesion distribution in both hemispheres.