Exploring the effects of restraining the use of gestures on narrative speech

Research on gesture production has emphasized the strong relationship between speech and gesture. Studies have explored whether the inability to gesture is detrimental to speech at different levels. However, findings are still inconclusive and research that focuses on a complete set of acoustic prosodic measures, including F0 and intensity are lacking. Also, studies have used very controlled tasks but evidence is lacking about spontaneous speech. The present study investigates the effects of restraining hand gestures on semi-spontaneous narrative speech. Twenty native Italian speakers described the content of short comic strips to a listener in two conditions: Non-Restraining gestures (N); Restraining gestures (R) (i.e., the speakers had to sit on their hands). The following speech variables were examined: speech length (number of words and speech length in seconds), disfluencies (filled pauses, self-corrections, repetitions, insertions, interruptions) and prosodic properties related to speech rate, F0 and intensity. Overall, the results showed that speakers’ inability to gesture does not significantly affect their narrative speech performance in terms of speech length, fluency and acoustic features. When repeating the analysis with the exclusion of the participants who gestured very little in the N condition, however, a slightly different pattern of results emerged; this leaves open the possibility that the inability to gesture may impact individuals differently, depending on the extent to which they rely on gesture when speaking. Further work is needed to shed more light on the role of gestures on the prosodic level of speech production which also takes into account individuals’ communicative and cognitive inclinations.