The Grooved Pegboard Test (GPT) is used primarily as a measure of motor functioning, but some research indicates that performance on this test my also reflect cognitive factors, particularly attention and executive functioning. The aim of this study was to examine rule violations as a possible quantifiable measure of executive functioning, particularly inhibitory control. In a sample of 82 veterans undergoing neuropsychological evaluation at a Virginia (VA) outpatient clinic, we recorded instances of two types of rule violations: using the incorrect hand during insertion and placing pegs out of sequence. Criterion measures included the Trail Making Test, the Tower of London, and the Stroop Color and Word Test. As hypothesized, total number of rule violations correlated moderately to strongly with the criterion measures. Notably, 60% of individuals committing two or more rule violations were impaired on at least two of the criterion measures, whereas only 17% of individuals without any rule violations were impaired on two criterion measures. Rule violations during the GPT provide valuable supplementary data for assessing executive dysfunction with no additional task demand or time cost. These data suggest that making two or more errors should raise suspicion of executive dysfunction.
Keywords: Executive functioning; Grooved Pegboard Test; neuropsychology; psychometrics.