APA Dictionary of Psychology

a neuropsychological test measuring information-processing speed, working memory, and sustained and divided attention. Developed in New Zealand in the 1950s for experimental purposes by cognitive psychologist Hubert Sampson, the PASAT was first used clinically in the early 1970s by Sampson and clinical neuropsychologist Dorothy M. A. Gronwall to evaluate cognitive deficits in patients with mild head injury. It later became widely used for patients with multiple sclerosis and in recent years has been used to assess the cognitive effects of other neurological conditions. In the original version of the test, a random sequence of 61 digits is presented in audiotaped format, and the participant must add each digit to the immediately preceding digit. For example, a sequence of 1, 5, and 7 would result in the responses 6 (1 + 5) and 12 (5 + 7). Four trials are used, differing in the rate of digit presentation: 2.4, 2.0, 1.6, and 1.2 seconds, respectively. Mean numbers of correct responses for each of the four trials are compared. Several revisions of the original test exist, with variations in methodology and in technology (e.g., computerized digit presentation)