The effects of traumatic brain injury on reporting and responding to causal relations: An investigation of sensitivity to reinforcement contingencies

Impairments in judging and responding to consequences that follow behaviour are often attributed to changes in various cognitive processes. An alternative conceptualization is that impairments may produce a reduction in sensitivity to reinforcement contingencies. The present investigation employed a methodology commonly used in research on judgements of causality to examine the effects of TBI on sensitivity to reinforcement contingencies. Participants were non-injured control subjects and adults with TBI. The experimental task required subjects to press a response key under a series of concurrent response-reinforcer contingencies that periodically delivered money for responding and not responding. Afterwards, subjects provided a judgement about each response-reinforcer contingency by reporting the amount of money earned for responding and for not responding. Results suggest that TBI reduced the sensitivity of judgements and responding under select contingencies. These results lend some support to the view that TBI may reduce sensitivity to reinforcement contingencies. Furthermore, the investigation highlights the potential benefits of employing methods commonly used in human and animal operant research for the study of TBI.