A study of the homeostatic level of stereotypy and other motor movements of persons with mental handicaps

Abstract

ABSTRACT. Stereotypy is one of the most common behaviours demonstrated by persons with mental handicaps. As such, it has generated a number of theories concerning its origin or maintenance. One of these theories, the homeostatic one, suggests that some persons engage in stereotypies and other motor behaviours in order to maintain a relatively constant level of responding. If this was indeed true, the fact would have important implications for treatment, i.e. those persons who varied rates of both stereotypy and other movements but retained an overall level of motoric responding would seem to be those for whom procedures like the differential reinforcement of incompatible behaviour would be highly appropriate. The purpose of this paper was to determine whether some people do engage in constant levels of responding, and it did so by collecting data on stereotypy and other motor movements of 12 persons with retardation. Collected throughout the sehool day for 5 consecutive days on micro‐computers, the data showed (1) that the stereotypic responding of four subjects was extraordinarily consistent, with the most deviant day's total being only 15 or 16% from the mean of the 5 days, (2) that other motor movements were inconsistent for all but one subject, but (3) that total movement (i.e. stereotypy plus other motor movements) was very high and was consistent for most subjects. The data were discussed in terms of assessing baselines for subjects for whom reinforcing adaptive motor movements would seem an appropriate means for reducing stereotypic responding.

Automated Detection of Stereotypical Motor Movements

“…These analyses could also guide and evaluate intervention efforts (Rapp and Vollmer 2005), including making predictions about which treatments would be most effective (Repp et al 1992). For instance, individuals with ASD who display high levels of stereotypical motor movements across all situations may be suitable candidates for pharmacological intervention , whereas individuals who display high levels of stereotypical motor movements only in some situations may be most suitable for behavioral interventions (Dib and Sturmey 2007;Lancioni et al 2009;Loftin et al 2008).…”

“…Such analyses could shed light on potential underlying mechanisms and environmental interactions that maintain these behaviors (Hall et al 2003). Invariant rates of stereotypical motor movements, regardless of environmental setting, would suggest a biological substrate while systematic fluctuations in movement rates across environments or in the presence of certain stimuli would suggest behavioral, homeostatic, or sensory substrates (Repp et al 1992).…”

“…Homeostatic theories assume there is an optimal level of stimulation for an individual (Leuba 1955) and that stereotypical motor movements serve a compensatory function to increase arousal in under-stimulating environments or reduce arousal in over-stimulating environments (Brett and Levine 1979;Hutt 1978;Hutt andHutt 1965, 1970;Kinsbourne 1980;Repp et al 1992). …”

“…1 Several stereotypical motor movements have been identified (Goldman et al 2009; Lewis and Bodfish 1998;Repp et al 1992), the most prevalent among them being body rocking, mouthing, and complex hand and finger movements (Goldman et al 2009;LaGrow and Repp 1984;Symons et al 2005). Stereotypical motor movements occur frequently in people with mental retardation, developmental disabilities, and genetic syndromes (Bishop et al 2006;Bodfish et al 2000;Campbell et al 1990; Lewis and Bodfish 1998;Militerni et al 2002;Moss et al 2009), and less frequently in typically developing children and adults (Rojahn et al 2000).…”

The use of functional analyses to test causes of self‐injurious behaviour: rationale, current status and future directions

“…If SIB is shown reliably to decrease when the client engages in other behaviour, then treatment might include reinforcing those other behaviours. The existence of such a relationship for some people who engage in stereotypy has been demonstrated (Repp et al, 1988b), and the possibility of its existence for some who engage in SIB would not seem unreasonable.…”