Fig. 3.

Comparison of optimal prior and flat prior reconstruction in simulations and with physiological data. A: original spectrogram of a speech sample. B: optimal prior reconstruction of the speech spectrogram from simulated responses of 8 neurons that were spectrally narrowly tuned and widely spaced produced a reasonably complete spectrogram. C: flat prior reconstruction using the same neurons as in B results in a sparser spectrogram with gaps between the explicitly encoded frequency channels. D: comparison of the accuracy of optimal prior and flat prior reconstruction for 30 different sentences using physiological responses of auditory cortex (AI) 250 neurons. The distribution of the correlation coefficients for optimal prior reconstruction was consistently higher than that for the flat prior method. E: example of optimal prior reconstruction of 1 sentence from physiological data. F: flat prior reconstruction using the same data produces a less accurate match to the original spectrogram.