Social Motor Coordination in Unaffected Relatives of Schizophrenia Patients: A Potential Intermediate Phenotype

Abstract

Intermediate endophenotypes emerge as an important concept in the study of schizophrenia. Although research on phenotypes mainly investigated cognitive, metabolic or neurophysiological markers so far, some authors also examined the motor behavior anomalies as a potential trait-marker of the disease. However, no research has investigated social motor coordination despite the possible importance of its anomalies in schizophrenia. The aim of this study was thus to determine whether coordination modifications previously demonstrated in schizophrenia are trait-markers that might be associated with the risk for this pathology. Interpersonal motor coordination in 27 unaffected first-degree relatives of schizophrenia patients and 27 healthy controls was assessed using a hand-held pendulum task to examine the presence of interpersonal coordination impairments in individuals at risk for the disorder. Measures of neurologic soft signs, clinical variables and neurocognitive functions were collected to assess the cognitive and clinical correlates of social coordination impairments in at-risk relatives. After controlling for potential confounding variables, unaffected relatives of schizophrenia patients had impaired intentional interpersonal coordination compared to healthy controls while unintentional interpersonal coordination was preserved. More specifically, in intentional coordination, the unaffected relatives of schizophrenia patients exhibited coordination patterns that had greater variability and in which relatives did not lead the coordination. These results show that unaffected relatives of schizophrenia patients, like the patients themselves, also present deficits in intentional interpersonal coordination. For the first time, these results suggest that intentional interpersonal coordination impairments might be a potential motor intermediate endophenotype of schizophrenia opening new perspectives for early diagnosis.

Interpersonal Coordination: Methods, Achievements, and Challenges

“…Therefore, these devices enable an indirect measure of body movement. A potentiometer attached to a rigid pendulum that can only be moved back and forth in a single direction has been used to measure the spatial displacement of the hand that moves it in tasks that require coordination of movement between two people sitting side by side in chairs ( Marmelat and Delignières, 2012 ; Del-Monte et al, 2013 ; Varlet et al, 2014a ; Ouwehand and Peper, 2015 ; Benerink et al, 2016 ). As with most time series data, angular displacement data recorded by potentiometers require processing and analysis that include at least three components: first, the application of filters to reduce noise from movements, such as a bidirectional Butterworth filter; second, the estimation of the relative phase between angular displacements of participants’ pendulums, typically by using a Hilbert transform; third, the computation of coordination variability and phase shift to analyze synchronization stability and establish which participant followed or led coordination with his/her partner.…”

“…For example, Vicaria and Dickens (2016) presented an exhaustive meta-analysis of interpersonal coordination outcomes, and Rennung and Göritz (2016) did the same with the prosocial consequences of interpersonal synchrony. Other recent publications reviewed findings of interpersonal coordination in particular samples, such as patients with mental disorders ( Del-Monte et al, 2013 ), and specific contexts such as dance ( Torrents et al, 2016 ) and sports ( Araújo et al, 2016 ; Passos and Chow, 2016 ; Yamamoto et al, 2016 ; Seifert et al, 2017 ). Jakubowski et al (2017) compared the efficacy of three different computer vision techniques with motion capture systems to study interpersonal coordination in musical performances.…”

Nonverbal Synchrony in Social Interactions of Patients with Schizophrenia Indicates Socio-Communicative Deficits

“…A number of studies have evaluated more laboratory-based forms of intentional and unintentional motor-coordination using e.g. hand-held pendulums operated by schizophrenia patients or unaffected relatives and control participants [ 22 , 54 ].…”

Social priming enhances interpersonal synchronization and feeling of connectedness towards schizophrenia patients

“…The importance of this exploratory result was confirmed by a more recent study showing that unaffected first-degree relatives of schizophrenia patients presented similar deficits in intentional interpersonal coordination. Consequently, it has been proposed that intentional interpersonal coordination might be a potential motor intermediate endophenotype of schizophrenia 28 . However, the question whether the consequences of such impairments have an impact on everyday social interactions, such as the feeling of connectedness, remains unclear.…”