The Adjusting-Paced Serial Addition Test (Adjusting-PSAT): thresholds for speed of information processing as a function of stimulus modality and problem complexity

Arch Clin Neuropsychol. 2004 Jan;19(1):131-43.


A modified computer version of the PASAT (Adjusting-PSAT; ) is described that measures speed of information processing and working memory by means of a temporal threshold rather than number of correct responses. This is accomplished by making the duration of the interval between numbers depend on the correctness of responding-a correct response decreases the interval between digits and an incorrect response increases the interval. Modality of presentation (visual and auditory) was factorially combined with problem difficulty (answers between 2-10 or 2-18). Performance of 60 healthy student volunteers on the Adjusting-PSAT was compared to that obtained on several traditional neuropsychological measures (Digit Span, Trail Making Test, and Symbol Digit Modality Test) and on a test of basic addition skills. The visual version of the test produced a lower threshold than did the auditory version, but problem difficulty did not produce a significant effect. Of the neuropsychological tests, Trails-B (TMT-B) was most highly correlated with thresholds. However, regression analyses revealed that math ability accounted for more variance than did TMT-B. The clinical implications of these finding are discussed.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acoustic Stimulation
  • Adolescent
  • Adult
  • Diagnosis, Computer-Assisted
  • Humans
  • Mathematics
  • Mental Processes*
  • Neuropsychological Tests*
  • Photic Stimulation
  • Problem Solving
  • Reference Values
  • Time Factors