Suppressed working memory on the WMS-III as a marker for poor effort

Area of Science:

• Neuropsychology
• Forensic Psychology

Background:

• Assessing response bias is crucial in forensic evaluations.
• The Weschler Memory Scale-III (WMS-III) memory-WMI discrepancy scores are proposed indicators of poor effort.

Purpose of the Study:

• To evaluate the clinical utility of WMS-III memory-WMI discrepancy scores for identifying poor effort in personal injury litigants.
• To determine the effectiveness of these discrepancy scores in distinguishing between adequate and poor effort groups.

Main Methods:

• Utilized discriminant function analyses on WMS-III memory-WMI discrepancy scores from 145 personal injury litigants (19 poor effort, 126 adequate effort).
• Examined classification rates, sensitivity, specificity, and predictive power of the discrepancy scores.

Main Results:

• The poor effort group exhibited significantly lower WMS-III memory index scores and larger memory-WMI discrepancies.
• Overall classification rates were poor (60.0%–63.4%).
• High specificity and negative predictive power were observed for suppressed attention-concentration relative to memory, but sensitivity and positive predictive power were unacceptably low.

Conclusions:

• WMS-III memory-WMI discrepancy scores lack sufficient clinical utility for reliably detecting poor effort.
• These scores should be used with caution as indicators of response set in forensic evaluations.
• Further research may be needed to identify more robust measures of response bias.