Beat and metaphoric gestures are differentially associated with regional cerebellar and cortical volumes

Abstract

Gestures represent an integral aspect of interpersonal communication, and they are closely linked with language and thought. Brain regions for language processing overlap with those for gesture processing. Two types of gesticulation, beat gestures and metaphoric gestures are particularly important for understanding the taxonomy of co-speech gestures. Here, we investigated gesture production during taped interviews with respect to regional brain volume. First, we were interested in whether beat gesture production is associated with similar regions as metaphoric gesture. Second, we investigated whether cortical regions associated with metaphoric gesture processing are linked to gesture production based on correlations with brain volumes. We found that beat gestures are uniquely related to regional volume in cerebellar regions previously implicated in discrete motor timing. We suggest that these gestures may be an artifact of the timing processes of the cerebellum that are important for the timing of vocalizations. Second, our findings indicate that brain volumes in regions of the left hemisphere previously implicated in metaphoric gesture processing are positively correlated with metaphoric gesture production. Together, this novel work extends our understanding of left hemisphere regions associated with gesture to indicate their importance in gesture production, and also suggests that beat gestures may be especially unique. This provides important insight into the taxonomy of co-speech gestures, and also further insight into the general role of the cerebellum in language.

The relationship between co-speech gesture production and macrolinguistic discourse abilities in people with focal brain injury

“…The idea that gesture and speech are intimately connected is supported by neuroimaging evidence (Bernard et al, 2015; Green et al, 2009; Xu et al, 2009). Broca’s area, a core language processing area, is implicated in both production and comprehension of gesture (Gentilucci & Volta, 2008; Häberling, Corballis, & Corballis, 2016).…”

“…Gesture and speech also share overlapping neural substrates (e.g., Bernard, Millman, & Mittal, 2015; Gentilucci & Volta, 2008; Green et al, 2009; Willems & Hagoort, 2007; Xu et al, 2009). After focal brain injury, gesture might compensate for or facilitate speech in cases of verbal impairment (e.g., Ahlsén, 1991; Akhavan, Göksun, & Nozari, in press; Akhavan, Nozari, & Göksun, 2017; Cicone et al, 1979; Cocks, Hird, & Kirsner, 2007; Feyereisen, 1983; Glosser, Wiener, & Kaplan, 1986; Göksun, Lehet, Malykhina, & Chatterjee, 2015; Herrmann et al, 1988; Hogrefe, Ziegler, Weidinger, & Goldenberg, 2012; Lanyon & Rose, 2009; Pritchard, Dipper, Morgan, & Cocks, 2015; Scharp, Tompkins, & Iverson, 2007).…”

“…Only a few studies have investigated specific brain areas associated with spontaneous gesture production (e.g., Bernard et al, 2015; Göksun et al, 2013, 2015; Hogrefe et al, 2017). Gesture production after brain damage is frequently investigated in terms of comprehensibility or quality of gestures (Hogrefe et al, 2017) or for a specific linguistic category (e.g., spatial language gestures in Göksun et al, 2013, 2015).…”

“…However, co-speech gestures are different than emblems, pantomime gestures, or self-touch and grooming as co-speech gestures rely on the speech for their occurrence (McNeill, 1992). Besides, such artificial settings do not provide an ecologically valid context for studying spontaneous co-speech gesture production (for a discussion, see Bernard et al, 2015.…”

“…Yet, the literature on the neural substrates of gestures usually reports content-carrying gestures alone (Bernard et al, 2015; Leonard & Cummins, 2011). In that sense, including gesture subtypes that are less emphasized in the literature (e.g., beat gestures) in a naturalistic setting would extend our understanding of the relationship between spontaneous co-speech gestures and discourse-level competence, as well as its neural substrates.…”