As recently as a few decades ago, autism was still regarded as a medical curiosity
to some degree, conjuring up visions of a child who walks on tip-toe, stares vacantly into
space, or rocks back and forth repetitively, but at the same time excel at the Embedded
Figures Task (Shah and Frith, 1983). The prevalence of autism around this time period
(1960's) was reported to range from 0.7 to 4.5/10,000 children, compared to a current
estimate of every 5-6 of 1000 children receiving the diagnosis today (Gupta, 2004).
The aim of the current study is to determine the efficacy of extinction as a treatment for
stimulus over-selectivity in children with ASD, through the use of a discriminationlearning
The first hypothesis was that extinction would decrease stimulus over-selectivity
for children with ASD across all functional levels. The second hypothesis was that
extinction would have a greater efficacy as an intervention for over-selectivity in high
functioning children with ASD than with either moderate or low functioning participants,
and finally it was hypothesised that extinction would have greater efficacy as an
intervention for over-selectivity in moderate functioning participants than for low
functioning participants. The research was conducted in the hope that this study will enhance knowledge of the issue of over-selection within both the area of autism but also any relevant setting, and will yield clinically useful information with regard to extinction as an intervention for this problem.