Rhythmic factors in the determination of perceived stress

Abstract

Previous work has shown that when subjects are required to comprehend sentences and press a button on hearing a word beginning with a particular sound, they react faster to targets on stressed words than on unstressed words. This experiment investigated the role of rhythm in determining perceived stress. Twenty‐four sentences were recorded in a strict rhythm (one stress every 500 msec). In each sentence, two monosyllabic words occurred together (e.g., “The children were frigthened when they saw a black dog in the garden”); the second of these was stressed. A silent interval of 250 msec (half a beat) was spliced into a copy of each sentence immediately before the first of the two monosyllables. The target could be the sound beginning either the first or the second monosyllable. Thus, each sentence occurred in four versions—twice, with, twice without silent interval, and twice with first, twice with second target. Each subject heard only one version of each sentence. If rhythm is sufficient to determine perceived stress, reaction time to the first target (/b/ above) should be faster when the silent interval is present than without it, since the interval will cause the next accent to be expected half a beat early; reaction time to the second target (/d/ above), however, should be faster when the silent interval is absent. Exactly this interaction was found.