FIGURE 13-19 Neural Replay? Hippocampal cell activity suggests that rats dream about their experiences. Dots on the periphery of the circles represent the activity of 42 hippocampal cells recorded at the same time during (left) NREM sleep before a food-searching task, (center) the food-searching task, and (right) NREM sleep after the task. No strong correlations among cells emerged during the NREM sleep that preceded the food search, but correlations were strong among cells during the food search and during the subsequent slow-wave sleep.

Information from M. A. Wilson & B. L. McNaughton (1994). Reactivation of hippocampal ensemble memories during sleep. Science, 165, p. 678.