Can you feel my rhythm? Interpersonal coordination between a child with deafblindness and their mentor

How can you develop language if you are born without proper sight and hearing? Children with congenital deafblindness face profound difficulties in acquiring language, largely due to a lack of access to language in their environment. Indeed, only a few people with congenital deafblindness acquire language beyond the level of naming a limited amount of things, using tactile signs. Language is extremely powerful in extending the boundaries of communication, and not acquiring language proficiency is detrimental for someone’s developmental opportunities throughout life. To enable more children with congenital deafblindness to become more proficient in language, we need to better understand their individual paths to language. Language does not appear and develop all of a sudden, regardless of the presence or absence of any sensory impairments. Instead, language emerges from and builds upon processes underlying interpersonal interaction, such as imitation, attunement, synchronization, and coordination. A detailed understanding of interpersonal interaction between children with deafblindness and significant others promises to yield vital understanding of opportunities to learn language. In this case-study, we investigated interpersonal interaction between a child with congenital deafblindness and their mentor in detail. For this study, we analyzed interpersonal interaction using a video that was previously recorded for an effect study (Huiskens, 2015). We manually coded the harmonicity of the interaction, using an earlier developed coding system (Janssen et al., 2003). In addition, we tracked the hand movements of the child and the mentor in the video. We confined the coding and motion tracking to episodes in the video in which the head and at least one of the hands of both the child and mentor was visible. The child sat at the lap of the mentor and both did not change their posture significantly (e.g. going from sitting to standing). This resulted in the further analyses of two episodes (~ 130 – 150 sec.): One episode with a predominantly harmonious interaction, and one episode with a predominantly disharmonious interaction. For both episodes, we investigated the attunement of velocity and acceleration of child’s and mentor’s hand movements. First, we visualized and described the velocity and acceleration of hand movements over time, across the episodes. Second, we applied Cross-Recurrence Quantification Analysis (CRQA) on the timeseries of the velocity and acceleration of child’s and mentor’s hand movements. CRQA informs about the stability, strength and dynamics of coordination between two coupled dynamical systems, in this case the child and their mentor. We found that the movement profiles in the disharmonious interaction were more capricious than in the harmonious interaction. Furthermore, we found a more evenly balanced leader-follower pattern and more attunement in the harmonious interaction, compared to the disharmonious interaction. Our results thus show that the way in which the child with congenital deafblindness and their mentor move their hands together from moment to moment is closely related to the global nature of their interpersonal interaction. Our study is the first to apply a combination of detailed motion tracking and coordination dynamics analysis with more qualitative methods to investigate the interpersonal interactions between children with deafblindness and significant others. Using these methods, we found that harmonicity of the interaction is evident from the coupling and attunement between the child and their environment over time. Similarly, opportunities for language development arise from coordination between the child and their environment – and in fact are intertwined with harmonicity itself. We therefore believe that more studies on coordination between children and their environment will lead to a better understanding of the many paths leading to language for children with deafblindness.