Figure 4.

Two other types of memory cells. (A1– 3) This cell is almost silent in the baseline condition (A1), as if it were not related to the task. As the monkey adapts to the force field, however, the cell increases its firing rate and acquires a directional tuning (A2). The cell maintains its tuning curve during washout (A3), when the force is turned off. The waveforms plotted in the top right quadrants show that the recordings were stable throughout the experimental session. Note, in particular, that the activity of the cell at baseline is low, but not equal to zero. (B1– 3) In this case, a cell initially tuned in the baseline condition (B1) loses its tuning as the monkey adapts to the force-field condition (B2). During washout (B3), the cell maintains this pattern.