Psycholegal Implications of Malingered Head Trauma

Preliminary Validation of a New Measure of Negative Response Bias: The Temporal Memory Sequence Test

The Temporal Memory Sequence Test (TMST) is a new measure of negative response bias (NRB) that was developed to enrich the forced-choice paradigm. The TMST does not resemble the common structure of forced-choice tests and is presented as a temporal recall memory test. The validation sample consisted of 81 participants: 21 healthy control participants, 20 coached simulators, and 40 patients with acquired brain injury (ABI). The TMST had high reliability and significantly high positive correlations with the Test of Memory Malingering and Word Memory Test effort scales. Moreover, the TMST effort scales exhibited high negative correlations with the Glasgow Coma Scale, thus validating the previously reported association between probable malingering and mild traumatic brain injury. A suggested cutoff score yielded acceptable classification rates in the ABI group as well as in the simulator and control groups. The TMST appears to be a promising measure of NRB detection, with respectable rates of reliability and construct and criterion validity.

Detection of Malingered Neurocognitive Dysfunction Among Patients with Acquired Brain Injuries

The Word Memory Test (WMT) is one of the most sensitive forced-choice tests available designed to evaluate negative response bias (NRB). Presently there is no valid verbal test designed to evaluate NRB for Hebrew-speaking patients. The aims of the present study were to validate the response bias measures of the WMT among Hebrew-speaking patients with acquired brain injuries and to reveal the malingering base rate among Israeli patients involved in compensation-seeking. Participants were 112 patients. The Test of Memory Malingering (TOMM) was used for convergent validity and injury related variables were used for concurrent validity. A translated version of the WMT had high split-half reliability. Regarding convergent validity, WMT effort measures had high positive correlations with the TOMM. Moreover, based on TOMM cutoff scores for classification, the WMT had reasonable classification rates. Regarding concurrent validity, multivariate logistic regression revealed that failure in the WMT was significantly predicted by normal brainscans and involvement in compensation-seeking behavior. The baserate of probable malingering was 34%. These findings emphasize the universality of the WMT in detecting NRB and establishing a malingered neurocognitive dysfunction baserate among Israeli patients involved in compensation-seeking.

Compensation and Malingering in Traumatic Brain Injury: A Dose-Response Relationship?

The purpose of this study was to determine if there is a dose-response relationship between potential monetary compensation and failure on psychological indicators of malingering in traumatic brain injury. 332 traumatic brain injury patients were divided into three groups based on incentive to perform poorly on neuropsychological testing: no incentive; limited incentive as provided by State law; high incentive as provided by Federal law. The rate of failure on five well-validated malingering indicators across these groups was examined. Cases handled under Federal workers compensation laws showed considerably higher rates of failure and diagnosable malingering than cases handled under State law. The findings indicate that monetary compensation associated with workers compensation claims is a major motive for exaggeration and malingering of problems attributed to work-related brain injuries. The clinician's index of suspicion regarding exaggeration and malingering of symptoms and deficits should be much higher in the context of Federal workers compensation claims, particularly in patients who have suffered only mild traumatic brain injury.