Time Series Analyses of the Responses to Sensory Stimuli of Children with Severe and Multiple Disabilities

Abstract

Severe and multiple disabilities (SMD) refers to the simultaneous occurrence of intellectual and physical problems. SMD in children is difficult to assess, as they often do not have the proper language or bodily responses to represent their feelings. In this study, we propose a methodology for evaluating reactions of children with SMD to sensory stimuli that does not rely on observations by humans, but rather is based on automatic detection of video-recorded data and quantification by time-series analyses. We present two case studies with typical participants: one with large body movements (P1) and another with subtle body movements (P2). For P1, it was observed that he showed larger bodily movements just before the onset of tactile stimuli, while he became silent for approximately 10 s after the onset, with the stimuli causing him to reduce self-stimulatory behavior and pay attention to his external environment. For P2, two quantitative methodologies – correlation coefficient and Granger causality – were adopted, to compare behavioral difference during the presentation of either sour or sweet taste stimuli. For the sweet conditions, the movement of the mouth was considered to be generated by some internal causes. Through these experiments, we confirmed the authenticity of assessments made by the participants’ caregivers, and also revealed otherwise unseen behavioral patterns and structures.