Infants' and adults' use of duration and intensity cues in the segmentation of tone patterns

Adults and 8-month-olds were presented with sequences in which every third complex tone was either longer or more intense. Segmentation was measured b y comparing the detection of silent gaps inserted into three possible locat ions in each pattern: Silent gaps inserted at perceived segmentation bounda ries are harder to detect than gaps within perceived phrases or groups. A g o/no-go conditioned head-turn (hand-raising for adults) procedure was used. In Experiment 1, detection was worse for the gaps following the longer com plex tones than for the gaps at the other locations, suggesting that the lo nger tones marked the ends of perceived groups for both infants and adults. Experiment 2 showed that an increase in intensity did not result in any sy stematic grouping at either age.