TEMPO DISCRIMINATION BY 4-MONTH-OLD BABIES

The present experiment tested the tempo discrimination abilities of four month-old infants, as a function of tempo range, to investigate whether a similar range of tempo sensitivity is found in infants as in adults. Isochronous auditory sequences were presented with a tempo of 100, 300 or 600 ms inter-onset interval (101). Infants were conditioned to associate the auditory sequence and a red light. In an habituation phase, sequences of equal 101 were presented successively, until an habituation criterion was reached. Then for the next three trials, 24 infants (mean age 4;7) heard a sequence with a 15 % faster 101, and the control group of 15 infants (mean age 4; 18) heard the unchanged standard IOI. A reaction to novelty, expressed by longer visual fixations to the light was expected in the experimental group if the two tempi were discriminated. The results show that infants are sensitive to a 15 % 101 increment for habituation IOI of 300 and 600 ms, but not for 100 ms IOI. Infants discriminate isochronous sequences on the basis of tempo variations, in the same tempo range as adults. These data support the hypothesis that regularity extractor mechanisms are functional at the age of 4 months.