Temporal discrimination in the goldfish

Abstract

The capacities of the goldfish to detect changes in sound burst repetition rate were studied using classical respiratory conditioning. In experiment II, the just detectable amount of an instantaneous random jitter of burst period was measured as a function of mean period. In experiment I, the just detectable amount of slow sinusoidal jitter of burst period was measured for 3 burst types having different spectral and waveform characteristics. In experiment III, sinusoidal jitter detection thresholds were measured in the presence of varying degrees of random jitter. Rms [root mean square] sinusoidal and random jitter in a periodic train of bursts were approximately equally detectable. Sinusoidal jitter detection depended on burst period duration and the short-term envelope definition and not on frequency-domain information. For a given burst period, stimulus jitter and an internal temporal noise added independently to determine period discriminability. Psychophysical estimates of internal temporal noise were 0.160 and 0.710 ms at periods of 5 and 10 ms, respectively. The burst period discrimination task is based on a measurement of the time interval (duration) between spikes in auditory neurons.