Video Modeling to Enhance Language Production in Identical Twins with Selective Mutism

Abstract

Background: Selective mutism (SM) is an anxiety-based communication disorder that significantly interferes with social, academic, and functional participation. Early intervention is critical to reduce long-term psychosocial risk. Objective: This case series examined the effects of a video modeling (VM) and video self-modeling (VSM) intervention on verbal output and lexical diversity in identical twins diagnosed with SM. Materials and Methods: A pre–post case series design was implemented in a university-based speech and hearing clinic. Outcome measures included Mean Length of Utterance (MLU), Type–Token Ratio (TTR), and Number of Spontaneous Utterances (NSU) derived from standardized conversational language samples. Results: Following intervention, NSU increased for both participants. However, MLU decreased for both, and TTR showed divergent patterns, increasing for Twin 2 but decreasing for Twin 1. Conclusion: VM may be effective in increasing verbal initiation and frequency in children with SM, though gains in linguistic complexity may require longer intervention durations.