The influence of an experimental manipulation on cognitive assessment scores in adults with mild intellectual disabilities : implications for clinical practice

摘要

Cognitive assessment is required to help determine whether an individual has an Intellectual Disability (ID). However, motivational influences upon performance may have an impact upon individuals’ scores. Past research has shown that being told that one is failing on a task affects test performance on subsequent tasks, and that personality moderates such an effect. This suggests that intrinsic motivation can be suppressed by the experience of failure. Individuals with IDs as a group have fewer opportunities to experience success. It is therefore hypothesised that an accumulation of failure experiences may demotivate such individuals in cognitive assessment situations, and that their perceived competence on a task will affect subsequent task performance. Twenty-five adults with mild IDs participated in a within-subjects experimental design. Perceived competence was manipulated by altering the difficulty of a task given to participants prior to a subsequent cognitive task. Participants’ perceived competence on one task was found to affect their performance on a subsequent cognitive task. Significant differences were found between performance on assessment tasks that were preceded by an easy task compared to a difficult task. No relationship was found between personality-motivational constructs and the effect of the experimental manipulation. Cognitive test scores in adults with IDs are affected by perceptions of success and failure on previous cognitive tasks. Clinicians undertaking cognitive assessments with this population should take steps to foster positive engagement in the process, in order to obtain more accurate test results.