Arousal Modulation during Engagement in Stereotypical and Repetitive Behaviours (SRB's)

Background:

While SRBs are a defining aspect of autism, the occurrence and function of such behaviours is often neglected. One view is that SRBs are linked to arousal mechanisms, which can be traced back to the theories of Leuba (1955) and Hutt (1963). Furthermore, despite the lack of empirical evidence, Guess & Carr (1991) have included this concept in their three stage model of SRB’s.

Objectives:

To investigate the connection between engagement in SRB’s and arousal. Data from two empirical studies will be presented.

Methods:

Both studies recorded salient contextual and behavioural data over multiple observation sessions. In the first, the occurrence of spontaneous eye blink rate (SEBR) (Monster, Chan & O’Connor 1978) was recorded as an indirect non-intrusive measure of arousal.  In the second study, direct physiological and endocrine assessments were made of both sympathetic nervous system arousal (skin conductance response (SCR)), and HPA activity (salivary cortisol assaying). Participants in both studies were male aged 6-11yrs and attended a behavioural school, where the research was conducted.

Results:

Study 1: Analysis shows that while there was only limited variation in SEBR across task activity, arousal was shown to vary significantly during engagement in certain SRB’s. Arousal levels were noted to change prior to, during and after engagement. The magnitude of difference being more pronounced for physical type behaviours.

Study 2: The data supports the earlier findings of the SEBR study, suggesting that changes in arousal status corresponds with engagement in SRB’s.

Conclusions:

It is suggested therefore, that a sub-group of SRBs may provide a means of modulating psychological and physiological arousal. The results also suggest that arousal thresholds (minimal & maximal) may serve as antecedents for certain behaviours.