Automatic imitation in youngsters with Gilles de la Tourette syndrome: A behavioral study

ABSTRACT

It is widely known that humans have a tendency to imitate each other and that appropriate modulation of automatic imitative behaviors has a crucial function in social interactions. Gilles de la Tourette syndrome (GTS) is a childhood-onset neuropsychiatric disorder characterized by motor and phonic tics. Apart from tics, patients with GTS are often reported to show an abnormal tendency to automatically imitate others’ behaviors (i.e., echophenomena), which may be related to a failure in top-down inhibition of imitative response tendencies. The aim of the current study is to explore the top-down inhibitory mechanisms on automatic imitative behaviors in youngsters with GTS. Error rates and reaction times from 32 participants with GTS and 32 controls were collected in response to an automatic imitation task assessing the influence of observed movements displayed in the first-person perspective on congruent and incongruent motor responses. Results showed that participants with GTS had higher error rates than controls, and their responses were faster than those of controls in incompatible stimuli. Our findings provide novel evidence of a key difference between youngsters with GTS and typically developing participants in the ability to effectively control the production of own motor responses to sensory inputs deriving from observed actions.

KEYWORDS:

• Gilles de la Tourette syndrome
• echophenomena
• automatic imitation
• motor inhibition
• stimulus-response compatibility

Acknowledgments

The authors are grateful to all families who kindly agreed to participate in this study and to Monica Martignoni for assistance with testing and coding

Data availability statement

Materials and datasets generated and analysed during the current study are available in the Open Science Framework (OSF) repository, https://osf.io/z56mp/?view_only=8fc51ba604f4467cbf0f924eb08de343

Disclosure statement

The work presented in this manuscript has not been published and is not under consideration for publication elsewhere. We certify that all authors of the manuscript have agreed to the listing and have seen and approved the manuscript. We also certify that there are no affiliations with or involvement in any organization or entity with a direct financial interest in the subject matter or materials discussed in the manuscript (e.g., employment, consultancies, stock ownership, honoraria, and/or expert testimony).

Additional information

Funding

This work was supported by one research grant from the University of Milano-Bicocca to Ermanno Quadrelli.