A personal floor effect strategy to evaluate the validity of performance on memory tests

Area of Science:

• Forensic Psychology
• Neuropsychology
• Legal Psychology

Background:

• Assessing the validity of performance on cognitive tests is crucial in legal contexts, particularly during competency-to-stand-trial evaluations.
• Distinguishing genuine cognitive impairment from poor effort or malingering is a significant challenge in forensic assessments.

Purpose of the Study:

• To compare the effectiveness of four methods for assessing performance validity on a word recognition test.
• Specifically, to evaluate the utility of "normative" and "personal" floor effect strategies in identifying invalid performance among criminal defendants.

Main Methods:

• A sample of 609 criminal defendants undergoing competency-to-stand-trial evaluations were administered a word recognition test.
• Performance validity was assessed using four distinct methods, including "normative" and "personal" floor effect strategies.
• Convergent validity of the personal floor effect strategy was examined through four separate analyses.

Main Results:

• The "normative" floor effect strategy identified 16.9% of defendants as performing below the expected level for individuals with true memory impairment.
• The "personal" floor effect strategy identified 15.6% of defendants as performing below their own previously established level of intact ability.
• While identifying fewer instances of suspicious performance, the personal floor effect strategy showed potential for indicating poor effort or malingering.

Conclusions:

• The personal floor effect strategy offers a valid method for detecting suspect performance on memory tests in forensic populations.
• This strategy may be more indicative of deliberate poor effort or malingering than genuine memory deficits.
• Findings support the use of the personal floor effect strategy in competency evaluations to enhance the accuracy of cognitive assessments.