Phase sensitivity in electroreception.

The gymnotoid electric fish Hypopomus artedi discriminates between electric stimulus pulses with identical spectral amplitudes but different spectral phase functions. Behavioral results can be explained on the assumption that electroreception is based on a linear filter, approximately matched to the species' electric organ discharge. The impulse response of the appropriate matched filter, in fact, resembles the known impulse response of the electroreceptors involved.