Effects of reward and response cost on response inhibition in AD/HD, disruptive, anxious, and normal children.
Author/s: Jaap Oosterlaan
Issue: June, 1998
Attention deficit/hyperactivity disorder (AD/HD) has been conceptualized as a disorder which arises from a deficit in the capability for response inhibition (e.g., Barkley, 1994, 1997; Douglas, 1989; Newman & Wallace, 1993; Pennington & Ozonoff, 1996; Quay, 1988a, 1988b, 1997; Wender, 1972). That is, a failure to suppress inappropriate responding has been postulated to underlie the inattentive, hyperactive, and impulsive behavior that characterizes AD/HD.
Recently, however, the primacy of the response inhibition deficit has been called into question (e.g., Sonuga-Barke, 1995). That is, the possibility exists that the impairment in response inhibition in fact is only one aspect of a more general dysfunction. For example, it has been suggested that poor response inhibition originates from a frontal lobe deficit (Barkley et al., 1992; Pennington & Ozonoff, 1996; Shue & Douglas, 1992) or a lag in the development of the cognitive functions (Barkley, 1997; Barkley et al., 1992; Shue & Douglas, 1992). In the present study, we examine the possibility that poor response inhibition in AD/HD children actually is one of the many manifestations of a disinclination to invest effort, or stated differently, reflects a motivational deficit.
Different lines of research seem to converge in indicating that AD/HD children do not have the same motivational set as normal children. One line of research, aimed at localizing possible deficits in the information processing system, suggests that AD/HD children do not expend the effort necessary to perform optimally (see for reviews, Sergeant & Van der Meere, 1990a, 1990b, 1994; Van der Meere, 1996).
A second line of research suggests that the performance of AD/HD children seems to rely more strongly on the presence of contingencies than the performance of normal children (e.g., Douglas, 1985, 1989; Haenlein & Caul, 1987; Newman & Wallace, 1993; Quay, 1988a, 1988b, 1997; Wender, 1972). Reward and Response Cost in ADHD