Aging and response inhibition: Normative data for the Victoria Stroop Test

Increased difficulty with response inhibition occurs with age, although there is some controversy as to whether increased interference on Stroop tasks reflects difficulties with response inhibition or simply reflects generalized cognitive slowing. The Victoria Stroop Test (VST) is a brief, easily administered, psychometrically sound version of Stroop's original task. Performance on the VST by adults across a wide age span was examined to determine the association between age and various measures of interference. In addition, normative data for the VST were calculated. Participants were 272 healthy, community-dwelling adults age 18 to 94. Age and speed were negatively correlated on all trials of the VST. Importantly, however, interference scores that were corrected for baseline slowing remained highly correlated with age. Similarly, age and error scores on the interference trial were positively correlated, indicating decreased accuracy with age. These findings suggest that increased interference on Stroop tasks with age is not accounted for by simple cognitive slowing and more likely reflects other cognitive changes, such as decreased response inhibition. The VST has a number of administrative and psychometric strengths, and the provision of normative data should enhance its potential for clinical and research applications.