INFANTS DISCRIMINATION OF BIMODAL EVENTS ON THE BASIS OF RHYTHM AND TEMPO

A habituation procedure was used to examine 7-month-old infants' discr imination of changes in the rhythm (Expt 1) or the tempo (Expt 2) of a n auditory-visual event. Events consisted of videos of a hammer striki ng a surface displaying a characteristic rhythm and tempo along with t he synchronized impact sounds. In Expt 1, 32 infants were habituated t o one rhythm presented at a constant tempo followed by test trials of a novel rhythm presented at the familiar tempo. Across subjects, four different stimulus rhythms were presented at each of four different co nstant tempos. Infants demonstrated significant visual recovery to a n ovel rhythm at all stimulus tempos. In Expr 2, 32 infants were habitua ted to events displaying one rhythm and tempo followed by test trials presenting a novel tempo and the familiar rhythm. Infants showed a sig nificant visual recovery to a novel tempo, which was apparent across f our different underlying rhythm contexts. More robust discrimination w as observed for more extreme tempo contrasts. These data suggest that 7-month-old infants are sensitive to the invariant rhythm and tempo of bimodal events.