Auditory pattern recognition is fundamental to both speech and music. In humans, this ability is flexible across rates, indicating perception of the relative timing of temporal events over learning absolute interval durations. Several nonhuman vertebrate species have also demonstrated some degree of flexibility—following extensive training—in the perception of sound sequences that vary in relative timing. We evaluated the ability of a California sea lion with previous experience entraining body movements to rhythmic sounds to discriminate between isochronous and anisochronous stimuli presented in a go/no-go psychophysical paradigm. A small set of exemplar tempos (100, 140, and180 bpm) was used to establish the base procedure with stimuli differing in pattern but matched for number of pulses per interval. After training, enriching, and shuffling these problems, we tested the subject’s transfer performance on novel tempos from 96 to 184 bpm. This marine mammal subject rapidly and robustly categorized 40 unfamiliar patterned sound sequences as either isochronous or anisochronous without additional training. This work on rhythm perception, categorization, and generalization sits at the intersection of sensory biology and comparative cognition, and highlights the contributions of individual subjects to our understanding of auditory processing.
Jones et al. (Wed,) studied this question.