Central executive deficit and response to operant conditioning methods

Behaviour problems may exclude some patients with severe brain injury from rehabilitation. However, rehabilitation potential can be achieved when a behaviour modification approach is used. Not all patients respond favourably to the reinforcement, extinction and time-out interventions frequently cited in the literature. In this study neuropsychological factors are examined in an attempt to account for poor response. Tests of general intelligence, memory and frontal lobe functioning were poor at discriminating between brain injured ''responders'' and ''non-responders''. However, performance on a dual-task experiment did discriminate them. Controls and brain injured responders were able to allocate attentional resources appropriately when confronted with the need to monitor multiple events, while non-responders could not. Performance of the non-responders was taken as evidence of impairment of the central executive component of working memory. This inability to monitor two concurrent events results in functional difficulties that Baddeley (1986) has characterised the dysexecutive syndrome. Arguments are presented that suggest the presence of central executive deficit is responsible for aspects of behavioural dyscontrol after brain injury and why there is poor response to behaviour modification. Results suggest that while performance of all subjects improved with the provision of concurrent verbal feedback, this had special relevance in suggesting what should characterise operant procedures that will result in successful learning in patients who present with a severe dysexecutive syndrome.