Figure 2.

The frequency range of an FM sweep dominates over its direction

(A) Top: Spectrograms of the stimulus set used in the task. The animals were trained to discriminate between the safe sound (blue-ringed), and the unsafe sound (red-ringed) that differed in frequency range and sweep direction. They were then tested on novel stimuli (the other six sounds). Bottom: Generalization gradients showing the average response to each stimulus during the generalization phase.

(B) Similar to (A) for mice trained to discriminate FM sweeps with partially overlapping frequency range.

(C) Similar to (A) for mice trained to discriminate FMs with frequency-dependent preferred direction. The sound duration used for a-c was 20 ms, and the rate of frequency modulation was 50 octave/sec.

(D) Similar to (C) for mice trained to discriminate FMs with a duration of 40 ms and frequency modulation at 25 octave/sec. Error bars throughout represent standard error.