Preferred perceptual tempo for sound sequences: comparison of adults, children, and infants.

Previous motor and perceptual tasks have found optimal processing for sound sequences of a rate of around 600 msec. IOI (Interonset Interval). This zone of optimal processing (the rate at which discrimination is optimal) slows with age and is also found with infants. The current work investigated whether listeners "prefer" sequences at the rate for which they demonstrate optimal processing. In the present study, three experiments were done. Exp. 1 measured tempo preferences in adults who listened to pairs of isochronous sound sequences varying in tempo (from 100- to 1500-msec. IOI) and were required to indicate which they preferred. As expected, highest preferences were expressed for the intermediate tempi, supporting the hypothesis of a zone of preferred tempi comparable to the zone of optimal processing. Moreover, this preference for intermediate tempi was not affected by the temporal context (absence of differences between a fast, a slow, and a wide set of tempi). In Exp. 2, the same procedure was applied to 6- and 10-yr.-olds. Children in both groups had systematic preferences for the fastest tempi within a set, and the older children generally preferred slower sequences. Exp. 3 used a preference paradigm for sound sequences with 4-mo.-old infants, comparing sequences of 100- vs 300-msec. IOI, 300- vs 900-msec. IOI, and 100- vs 900-msec. IOI. No systematic tempo preferences were observed. We conclude that tempo discrimination and tempo preference may have some commonality (perhaps related to a zone of optimal processing), especially in adults, but that they also involve quite distinct processes which undergo different developmental sequences. Whereas adults prefer what they process the best, children prefer what is fastest (and therefore more attention-getting), and we have not been able to detect preferences in infants.