Restraining and encouraging the use of hand gestures: Effects on speech

Abstract

Previous studies have investigated the effects of the inability to make hand gestures on speakers' fluency; however, the question of whether encouraging speakers to gesture affects their fluency has received little attention. This study investigates the effect of restraining (Experiment 1) and encouraging (Experiment 2) hand gestures on the following correlates of speech: speech discourse length (number of words and discourse length in seconds), disfluencies (filled pauses, self-corrections, repetitions, insertions, interruptions, silent pauses), and acoustic properties (speech rate, measures of intensity and pitch). In two experiments, 10 native speakers of Italian took part in a narration task where they were asked to describe comic strips. Each experiment compared two conditions. In Experiment 1, subjects first received no instructions as to how to behave when narrating. Then they were told to sit on their hands while speaking. In Experiment 2, subjects first received no instructions and were then actively encouraged to use hand gestures. The results showed that restraining gestures leads to quieter and slower paced speech, while encouraging gestures triggers longer speech discourse, faster speech rate and more fluent and louder speech. Thus, both restraining and encouraging hand gestures seem to clearly affect prosodic properties of speech, particularly speech fluency.

Acoustic specification of upper limb movement in voicing: Exploratory data report and pre-registration

“…The current line of research yields tangible implications for the continuing study of gesture-speech prosody. If the current exploratory findings can be replicated, gesture acoustics (Cravotta et al, 2018;Pouw, Harrison, et al, 2018b) will be shown to have affordances for real interpersonal embodied couplings. Understanding the social communicative significance these couplings would be our next research question.…”

“…Namely, sudden increases in speech intensity and fundamental frequency are key properties that define the prosody of speech (Shattuck-Hufnagel & Ren, 2018;Wagner, Malisz, & Kopp, 2014), and spontaneous co-speech gestures are known to synchronize with such prosodic aspects of speech 6 (McClave, 1998;Rusiewicz & Esteve-Gibert, 2018). Scaling up to natural speech, other work has found that infants' babbling becomes more adult-like in voice quality when infants simultaneously and rhythmically move their arms (Ejiri & Masataka, 2001) and that encouraging gesture production during adults' speech production boosted maximum observed F0 and intensity of speech (Cravotta, Busà, & Prieto, 2018). Taken together, these findings are congruent with the idea that limb movement in itself is tied to changes in acoustic production, which provides a physical rudimentary basis for why gesture and speech tends to synchronize on the acoustic level.…”

Do gestures really facilitate speech production?

“…It appears that Rauscher et al (1996) did not, in fact, have any statistically significant results to support their influential claim that "speech with spatial content was less fluent when speakers could not gesture than when they could gesture" (ibid, p. 226). 1 Several studies in the last five decades, before and after Rauscher et al (1996), have also failed to find higher disfluency rates when speakers are prevented from gesturing than when they are allowed to gesture (Graham & Heywood, 1975;Rimé, Schiaratura, Hupet, & Ghysselinckx, 1984;Finlayson, Forrest, Lickley, & Beck, 2003;Hostetter, Alibali, & Kita, 2007;Hoetjes, Krahmer, & Swerts, 2014;Cravotta, Busà, & Prieto, 2018). Notably, none of the studies reporting null effects of gesture prevention distinguished between disfluencies during spatial and nonspatial speech; thus, arguably, these studies did not attempt to validate Rauscher et al's (1996) claim that gesture prevention selectively affects spatial speech.…”

Energy flows in gesture-speech physics: Exploratory findings and pre-registration of confirmatory analysis

“…Such effects were exaggerated when participants were standing as opposed to sitting, suggesting a role for anticipatory muscle activations as these are more reactive when postural stability is low (Cordo & Nashner, 1982). As mentioned, changes in F0 have in fact been associated with gesture in natural contexts as well (Cravotta, Grazia, & Prieto, 2018;McClave, 1998;Wagner et al, 2014). Thus, it seems that this particular type of gesture-speech F0 and intensity synchrony (excluding possibly other types), may arise naturally from gesture-speech physics.…”