Timing of experimentally elicited minimal responses as quantitative evidence for the use of intonation in projecting TRPs

In an RT experiment, subjects were asked to respond with minimal responses to prerecorded dialogs and a manipulated version of these dialogs that contained only intonation and pause information. Response delays and, especially, variances were higher to the impoverished, intonation only, stimuli than to the original recordings. It was also found that intonation only utterances ending in a mid-frequency pitch induced significantly longer response delays than utterances ending in a low pitch. These results are interpreted as evidence that just the intonation and pauses of a conversation already contain sufficient information to project end-of-utterance TRPs. However this information is measurably impoverished with respect to full speech to an extent that increases the “processing” time by 10%. Our subjects seemed to fall back to reacting to pauses when presented with intonation only utterances ending in a mid-frequency tone. This suggests that, in contrast to low or high end-tones, intonation contours that end in a mid-frequency tone might not contain any useful information for predicting end-of-utterance TRPs.