Interpersonal Motor Coordination Research Articles

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

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.

1283 – Social motor coordinations: a study with schizophrenia and social phobic patients

Introduction Social interactions dysfunctions make up core symptoms of many mental disorders and have been extensively studied through cognitive paradigms gathered under the concept of social cognition. Nevertheless, a growing body of literature have demonstrated that motor coordination is an important feature of these human social interactions but has been little studied in the context of mental diseases. Objective In this study, we propose to compare the processes of inter-agent coordination in healthy and socially impaired clinical populations (e.g. schizophrenia and social phobia patients). Method 20 schizophrenia and 20 social phobia patients were compared to 20 healthy subjects using an hand-held pendulum paradigm in intentional and unintentional interpersonal motor coordination, with different leadership conditions. All participants had psychopathological and neuropsychological evaluations. Results Our results demonstrated that each group of subject was characterised by specific signature concerning interpersonal motor coordination. More specifically, instability of the coordination and temporal delay between patient and controls revealed that schizophrenia impaired intentional coordination but not spontaneous non-intentional coordination whereas social phobia only affected leader conditions. Conclusion Taken altogether, these preliminary results give evidence that motor control through motor coordination behaviours is a fundamental part of social interactions deficits in schizophrenia and social phobia. These results lead us to examine if the evaluation of motor coordination during a social interactions could help to discriminate the deficits in social interactions and to propose specific therapy for their rehabilitation. Acknowledgements This research was supported by an Agence Nationale de la Recherche grant (Project SCAD # ANR-09- BLAN-0405-03).

Unintended interpersonal co-ordination: “can we march to the beat of our own drum?”

The main purpose of this article was to identify whether an interpersonal motor co-ordination emerges between two participants when they intentionally tried to not co-ordinate their movements between each other. To do this we conjointly examined both the emergence of the motor co-ordination (collective properties) between the two participants, and the maintenance of the individual intrinsic motor properties present in the interpersonal co-ordination. Six pairs of participants performed three situations where they freely moved their right forearm with no instructions (nor restrictions) on frequency or relative phase. The goal of the first two situations was for participants to intentionally co-ordinate ( P-on) or not co-ordinate ( P-off) their movements between each other. In order to determine his/her individual motor properties, each participant performed this task alone, in a third condition. The cross-wavelet transform (CWT) revealed in the P-off condition the emergence of an unintended co-ordination in the frequency domain. Moreover, random distribution of the relative phase appeared, in this condition, whereas in the P-on condition, we observed a collective organization especially at a relative phase around 0°. Conjointly, the wavelet transform (WT) showed the presence of individual intrinsic motor properties (motor signature) in the three conditions. These results indicate that, when there was information sharing, participants could not avoid (unintentionally) coordinating with someone. This study suggests that, in daily life, interactions with other people lead the individual motor behavior to adapt unintended motor co-ordination.