Freezing as an Underlying Mechanism of Silence in Children with Selective Mutism

• Applicants: Dr. Mathias Reiser; Professorin Dr. Christina Schwenck
• Subject Area: Personality Psychology, Clinical and Medical Psychology, Methodology
• Term: since 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 512587462

The project wants to investigating potential mechanisms of the failure to speak in children with selective mutism (SM) in comparison to children with social anxiety disorder (SAD) and typical development (TD). Precisely, we aim at investigating a) tonic autonomic arousal, b) reactions to neutral and anxiety-evoking stimuli with respect to various indicators of the freezing response, and c) the prediction of active coping via the freeze reaction, addressing flexibility in coping mechanisms, in these groups. To maximize differentiation between groups, our experimental paradigms manipulate situations to include a speech demand or a social evaluation or to be neutral. In the project we follow a multimethod approach to asses freezing behavior in children with SM, SAD and TD by combining several physiological measurements including body sway, heart rate and visual exploration and assess these measures in different situational contexts. A perceived threat can lead to three different responses, fight, flight or freeze. Freezing is expressed in immobility, including vocal and motor inhibition, increased muscle tonus, heart rate deceleration, reduced visual exploration and reduced body sway. Usually, it serves initial orientation and shifts into active coping behaviors, such as fight or flight. There are several findings of an association between increased and prolonged freezing and high levels of anxiety, indicating that freezing might be maladaptive in anxious individuals. Notably, the core symptom of SM is a failure to speak in certain social situations while showing unimpaired speaking behavior in other situations. As vocal inhibition itself is defined as a freeze reaction, it is possible that the silence in children with SM might be due to a dysfunctional maintenance of an initial freeze response. However, as of now, no study investigated whether freezing might be an underlying mechanism of the silence in children with SM. Evidence of such a mechanism would include clinical implications that would be important for successful treatment of children with SM and a better understanding of the disorder itself.

• DFG Programme: Research Grants
• International Connection: Netherlands
• Cooperation Partner: Professorin Dr. Karin Roelofs