Fig. 5.

Individual spike rasters and peristimulus time histograms (top) for the response of a particular single unit in the HVc to the BOS, Syn,Rev, and Con stimuli (see Fig. 4). Oscillograms (waveform representations of the sound pressure) of the stimuli are shown below each histogram. Thed′ for this particular single unit was 1.5. As shown in Figure 4, ∼75% of the recording sites showed greater selectivity than did this particular neuron, and this neuron, despite its evident selectivity, is among the less selective members of the population that was used for the studies involving the synthetic stimuli (d′ > 1).