Self-ordered pointing performance following severe closed-head injury

This study investigated executive aspects of working memory in a severe closed-head injured (CHI) population. Thirty-four severe CHI participants (>1 year postinjury) and 34 controls completed an abstract design version of Petrides and Milner's (1982) self-ordered pointing task. CHI participants made more errors than controls on the 16-item trial, but not the 9-item trial. Both CHI and control participants were able to make use of strategic processing to improve SOPT performance. As anticipated, errors on the SOPT were associated with another measure of working memory (i.e., Reading Span Test) for the control group. In contrast, for the CHI participants, errors on the SOPT were associated with a measure of delayed visual memory (i.e., Wechsler Memory Scale - Revised Visual Reproduction II subtest). Our findings suggest that, as a group, the primary factor resulting in poorer SOPT performance by the CHI group was a memory deficit and not the ability to utilize executive aspects of working memory.