Neural integration of speech and gesture in schizophrenia: Evidence for differential processing of metaphoric gestures

Abstract

Gestures are an important component of interpersonal communication. Especially, complex multimodal communication is assumed to be disrupted in patients with schizophrenia. In healthy subjects, differential neural integration processes for gestures in the context of concrete [iconic (IC) gestures] and abstract sentence contents [metaphoric (MP) gestures] had been demonstrated. With this study we wanted to investigate neural integration processes for both gesture types in patients with schizophrenia. During functional magnetic resonance imaging-data acquisition, 16 patients with schizophrenia (P) and a healthy control group (C) were shown videos of an actor performing IC and MP gestures and associated sentences. An isolated gesture (G) and isolated sentence condition (S) were included to separate unimodal from bimodal effects at the neural level. During IC conditions (IC > G ∩ IC > S) we found increased activity in the left posterior middle temporal gyrus (pMTG) in both groups. Whereas in the control group the left pMTG and the inferior frontal gyrus (IFG) were activated for the MP conditions (MP > G ∩ MP > S), no significant activation was found for the identical contrast in patients. The interaction of group (P/C) and gesture condition (MP/IC) revealed activation in the bilateral hippocampus, the left middle/superior temporal and IFG. Activation of the pMTG for the IC condition in both groups indicates intact neural integration of IC gestures in schizophrenia. However, failure to activate the left pMTG and IFG for MP co-verbal gestures suggests a disturbed integration of gestures embedded in an abstract sentence context. This study provides new insight into the neural integration of co-verbal gestures in patients with schizophrenia.

Gesture Performance in First- and Multiple-Episode Patients with Schizophrenia Spectrum Disorders

“…These neuropsychological deficits in gesture imitation in schizophrenia have been reported by others [9,45]. Furthermore, understanding of gestures in a specific context and underlying neuronal correlates was investigated in schizophrenia patients [46,47]. The authors noted specific difficulties in gesture understanding in an abstract sentence context (metaphoric gestures).…”

Functional Correlates of Increasing Gestural Articulatory Fluency Using a Miniature Second-Language Approach

“…Ten out of 12 participants reported decreasing reliance on English during gesture production from the first to the last session (1 reported no change, 1 did not answer the question). Interestingly, activation in the inferior frontal gyrus and middle temporal gyrus has consistently been reported during the observation of gestures (both iconic and metaphoric) [36,37]. It is interesting to note that gestures (i) appear to be strongly linked to speech [36,38,39,40,41,42] and (ii) have been shown to enhance sensorimotor representations of words.…”

“…Interestingly, activation in the inferior frontal gyrus and middle temporal gyrus has consistently been reported during the observation of gestures (both iconic and metaphoric) [36,37]. It is interesting to note that gestures (i) appear to be strongly linked to speech [36,38,39,40,41,42] and (ii) have been shown to enhance sensorimotor representations of words. When combined with traditional forms of word learning, gesture-based approaches have been shown to enhance second-language acquisition [11,43].…”

Mismatch and lexical retrieval gestures are associated with visual information processing, verbal production, and symptomatology in youth at high risk for psychosis

“…Investigations of gesture behavior have significantly improved our understanding of social and cognitive processes (McNeill, 1992; Goldin-Meadow et al, 1993; Streek, 1994; Alibali & DiRusso, 1999), and several studies have implicated abnormal gesture behavior in schizophrenia and spectrum groups (Trosi et al, 1998; Straube et al, 2013a,b; Walther et al, 2013a,b). However, to date our understanding of gesture behavior in the psychosis risk-period has been limited.…”

“…The field of psychosis research has prioritized the search for readily observable markers that can identify risk or elucidate pathogenic processes, leading researchers to examine gesture in patients with schizophrenia. Studies of individuals with psychosis have observed abnormal gesture activity (Troisi et al, 1998; Meilijson et al, 2004; Lavelle et al, 2013; Walther et al, 2013a;) with specific links to dysfunctional neural integration (Straube et al, 2013a), altered functional connectivity (Straube et al, 2013b), and both frontal cortex function and symptom severity (Walther et al, 2013b). Despite this growing body of evidence, and an earlier study observing gesture deficits in schizotypal personality disorder (SPD; Mittal et al, 2006), to date there have been no investigations of gesture in those at ultra high risk (UHR) for psychosis.…”