Cross validation of the b Test in a large known groups sample

Area of Science:

• Neuropsychology
• Cognitive Performance Assessment

Background:

• The b Test is a cognitive performance validity measure.
• Original validation involved non-credible participants and clinical comparison groups.

Purpose of the Study:

• Cross-validate the b Test using a known-groups sample.
• Evaluate the b Test's sensitivity and specificity with adjusted cut-offs.

Main Methods:

• Utilized a sample of 212 non-credible participants and 103 credible neuropsychological clinic patients.
• Analyzed the b Test's performance with original and revised E-score cut-offs.
• Examined sensitivity across subgroups, including feigned mild traumatic brain injury (mTBI) and psychiatric conditions.

Main Results:

• The original cut-off (≥155) showed high specificity (99%) but low sensitivity (41%).
• A lowered cut-off (≥82) maintained adequate specificity (≥90%) and increased sensitivity to 68%.
• Sensitivity was higher for feigned psychiatric symptoms (76% for depression, 67% for psychosis) than for feigned mTBI (58%).
• The b Test frequently identified cognitive dysfunction in somatoform disorders.

Conclusions:

• The b Test, with an adjusted cut-off, is valuable for detecting non-credible cognitive symptoms, particularly those linked to feigned psychiatric presentations.
• Fabricated deficits in processing speed and vigilance are more indicative of feigned psychiatric conditions than feigned mTBI.
• The b Test may also aid in identifying non-consciously created cognitive dysfunction in somatoform disorders.