Figure 2.

(A) Computer printouts of the superimposed swimming trajectories of a control and of an irradiated rat, trained in light, to find a visible platform when started from any of the four cardinal points (north, east, south, west) at the perimeter of the pool. The position of the platform was shifted from southwest to northeast. On the first day, the control rats swam initially to southwest, spending a few seconds there before approaching the visible platform in northeast. On day 3, they swam straight to the platform from all starting points. The irradiated rats covered the entire surface of the pool, never achieving a more compact and efficient form. (B) Latency to find the visible platform in control (CO) and irradiated (IR) rats. The control group reached asymptote of 5 s on the second day. The irradiated rats had an average latency of 40 s on day 1, and this did not change during the next two days.