Figure 7.

Histograms of single-neuron activity in the SG nucleus during presentations of the 400 ms tone conditioned stimulus in the unpaired pretraining session. Three examples are displayed for the groups trained on P17–P19 (top row), P24–P26 (middle row), or P31–P33 (bottom row). Stimulus-elicited activity is greater in the neurons recorded from the P17–P19 group relative to the neurons recorded from the older groups during the first 50 ms of the tone stimulus. Stimulus onset is depicted by the vertical gray line.