Detecting coached feigning using the Test of Memory Malingering (TOMM) and the Structured Inventory of Malingered Symptomatology (SIMS)

Undergraduate students were administered the Test of Memory Malingering (TOMM) and the Structured Inventory of the Malingered Symptomatology (SIMS) and asked to respond honestly, or instructed to feign cognitive dysfunction due to head injury. Before both instruments were administered, symptom-coached feigners were provided with some information about brain injury, while feigners who received a mix of symptom-coaching and test-coaching were given the same information plus advice on how to defeat symptom validity tests. Results show that, although the accuracy of both instruments appears to be somewhat reduced by a mix of symptom coaching and test coaching, the TOMM and SIMS are relatively resistant to different kinds of coaching.     

Performance of forensic and non-forensic adult psychiatric inpatients on the Test of Memory Malingering.

This study compared performance on the Test of Memory Malingering (TOMM [Tombaugh, T. N. (1996). Test of Memory Malingering (TOMM). New York: Multi Health Systems]) between a Forensic Psychiatric group and a Non-forensic Psychiatric group of 20 men each. It was hypothesized that the Forensic group would perform less well on the TOMM due to greater secondary gain for that population. The Forensic group (age, M=32.65 years; 16/20 were minorities) was composed of inpatients from a forensic psychiatric facility who had been referred for pre-trial evaluations. The Psychiatric group (age, M=41.00 years; 15/20 were Caucasian) were chosen from an inpatient psychiatric facility and had no pending legal involvement. As hypothesized, the Psychiatric group performed significantly better than the Forensic group on all TOMM trials. A TOMM score of below 45 on Trial 2 or the Retention Trial is consistent with probable response bias. Only one member of the Psychiatric group (the same individual) met this criterion, whereas seven members of the Forensic group met this criterion. The TOMM identified patients with pending legal charges as more likely to exert less effort than those with no obvious secondary gain.     

Deception strategies in children: Examination of forced choice recognition and verbal learning and memory techniques

Thirty-five children ages 6-12 years were asked to complete two alternate forms of the Hopkins Verbal Learning Test-Revised (HVLT-R), once with the instruction to feign cognitive impairment and once instructed to do their best. They were also asked to complete the Test of Memory Malingering (TOMM). Regardless of condition, children performed comparably to adult norms on the TOMM, obtaining a score of 45 or above on Trial 2. Regarding the HVLT-R, differences emerged only when children were initially told to "do their best," followed by a subsequent trial in which they were told feign impairment. Within this group of participants, children demonstrated significantly lower levels of learning across trials and fewer words recalled in comparison to when they were instructed to do their best. In contrast, no reliable differences on the HVLT-R were observed among children who were initially told to feign impairment and subsequently told to do their best. These results suggest that the elicitation of "feigned" impairment within this age group on the HVLT-R requires the initial provision of an opportunity for optimal performance.     

Depression and the Test of Memory Malingering

Research on the Test of Memory Malingering (TOMM) [Tombaugh, T. N., 1996. The Test of Memory Malingering. Toronto, Canada: Multi-Health Systems], has consistently shown that it is sensitive to exaggerated or deliberate faking of memory impairment, but it is relatively unaffected by a wide variety of neurological impairments causing genuine memory dysfunction. However, there is little research on the effects that affective disorders have on the TOMM. The current study examined how inpatients diagnosed with major depression performed on the TOMM. Results show that the TOMM is unaffected by affective state. These results, combined with those from previous research, provide converging evidence that performance on the TOMM below a cutoff score of 45 cannot be attributable to depression, neurological impairment, age or education.     

The Test of Memory Malingering (TOMM): normative data from cognitively intact, cognitively impaired, and elderly patients with dementia.

This research adds to the psychometric validation of the Test of Memory Malingering (TOMM) by providing data for samples of elderly patients who are cognitively intact, cognitively impaired (non-dementia), and with dementia. Subjects were 78 individuals referred for evaluation of memory complaints. Significant group differences emerged between the dementia group and the two other groups (normals and cognitively impaired), although the latter two did not differ from each other. One hundred percent of normals and 92.7% of the cognitively impaired group made fewer than five errors (the suggested cut-off) on Trial 2 or the Retention trial of the TOMM, yielding an overall correct classification rate of 94.7%. However, the rate of misclassification for persons with dementia was high whether using a cut-point score of five, eight, or ten errors. This investigation extends the validity and clinical utility of this instrument. Results suggest that the TOMM is an useful index for detecting the malingering of memory deficits, even in patients with cognitive impairment, but only when dementia can be ruled out.     

Financial incentive does not affect P300 (in response to certain episodic and semantic probe stimuli) in the Complex Trial Protocol (CTP) version of the Concealed Information Test (CIT) in detection of malingering

Previous research indicated that the skin conductance response of the autonomic nervous system in the Concealed Information Test (CIT) is typically increased in subjects who are financially and otherwise incentivized to defeat the CIT (the paradoxical “motivational impairment” effect). This is not the case for RT‐based CITs, nor P300 tests based on the three‐stimulus protocol for detection of cognitive malingering (although these are not the same as CITs). The present report is the first attempt to study the effect of financial motivation on the P300‐based Complex Trial Protocol using both episodic and semantic memory probe and irrelevant stimuli. The Test of Memory Malingering (TOMM) was used to validate behavioral differences between the two groups we created by offering one (paid) group but not another (unpaid) group a financial reward for beating our tests. Group behavioral differences on the TOMM did confirm group manipulations. Probe‐minus‐irrelevant P300 differences did not differ between groups, although as previously, semantic memory‐evoked P300s were larger than episodic memory‐evoked P300s.     

Test of Memory Malingering Performance is unaffected by laboratory-induced pain: implications for clinical use.

The Test of Memory Malingering (TOMM) is a well-validated and widely used forced-choice symptom validity test. However, little is known about how TOMM performance is affected by pain. The present study evaluated the sensitivity of the TOMM to pain induced in healthy participants via the cold-presser test. Participants (n=20 per group) were administered the TOMM under one of three conditions: (1) standard instructions; (2) instructions to simulate pain-related memory deficit in pursuit of personal injury litigation; (3) while experiencing cold-induced pain. Results indicate that TOMM performance was unaffected by laboratory-induced moderate to severe pain and support the TOMM's use in evaluating clinical patients with pain.     

Effects of severe depression on TOMM performance among disability-seeking outpatients.

The purpose of this study is to examine the effects of severe depression on the Test of Memory Malingering (TOMM). The present study examined whether 20 participants with high levels of depression, as measured by the Beck Depression Inventory 2nd Edition (BDI-II) and with current diagnoses of Major Depressive Disorder, would perform significantly worse on the TOMM than a control group. The results showed that the depressed and control groups did not have significant mean group differences on TOMM performance. Of the 20 depressed participants, only 2 on Trial 2 and 1 on the Retention Trial scored below the cutoff of 45, while none of the control participants performed in this range. The potential ameliorating effects of medications on the performance of the depressed group are discussed. The results indicate that the TOMM can be used with even severely depressed participants with only slight caution.     

Detecting feigned neuropsychological impairment with the Seashore Rhythm Test

Sixty undergraduate subjects were randomly assigned to one of three groups and completed the Seashore Rhythm Test (SRT) as part of an investigation regarding simulated neuropsychological impairment. A sophisticated simulator group was instructed to feign impairment and was provided information regarding traumatic brain injury (TBI) sequelae. A naive simulator group was instructed to feign impairment, but was given no such information. A control group was instructed to perform optimally. Additionally, SRT scores for 20 TBI subjects who completed neuropsychological evaluations were analyzed. Mean SRT scores for the sophisticated and naive simulators did not differ but were significantly lower when compared to control subjects and TBI subjects. A discriminate function analysis cutting score correctly classified 79% of subjects, while classification rates obtained with two previously investigated cutting scores were 64% and 72%. Implications of using these cutting scores are discussed. The findings indicate the SRT is a useful indicator of feigned neurological impairment. © 1998 John Wiley & Sons, Inc. J Clin Psychol 54: 431–438, 1998.     

Utility of TOMM Trial 1 as an indicator of effort in children and adolescents

Although measuring test compliance in a pediatric neuropsychological evaluation is important, increasing demands on clinicians' time and the need for efficiency during assessments may make it difficult to routinely include effort testing. This study investigated whether performance on Trial 1 of the Test of Memory Malingering (TOMM) is predictive of overall performance in children and adolescents with neurological disorders. Participants included 53 children and adolescents between six and 19 years (mean age = 12.4, SD = 4.1) who were followed through a neurology clinic at a tertiary care hospital. Several cutoff scores were examined, with the goal of maximizing positive predictive (accurate detection of failure on the TOMM) and negative predictive (accurate detection of passing the TOMM) values. Every participant who scored ≥36 on Trial 1 (n = 50) went on to pass the TOMM. This study is the first step in providing evidence that performance on Trial 1 might be used as a quick screening measure of overall performance on the TOMM in children and adolescents. Further research on this topic is warranted.     

Performance of mentally retarded forensic patients on the test of memory malingering

The utility of the Test of Memory Malingering (TOMM) with mentally retarded forensic patients was assessed. Twenty-one adjudicated forensic inpatients, who had been diagnosed with mental retardation, were administered the TOMM. The majority of these patients also suffered from an Axis I mental disorder. The participants attained a mean score of 48.7 on Trial 2, with only 1 participant scoring below the standard cutoff for malingering (i.e., 45). The participants attained a mean score of 49.4 on the Retention Trial, with no participants falling below the cutoff for malingering. The results clearly indicate that mildly retarded forensic patients can perform well on the TOMM. The findings provide evidence that the TOMM can be used in the assessment of mildly retarded criminal defendants with little fear of obtaining false indications of malingering.     

Detection of feigned recognition memory impairment using the old/new effect of the event-related potential.

Twenty-four undergraduate university students with no known neurological disorders completed the Recognition Memory Test (Warrington, A., 1984. Recognition Memory Test manual. Windsor, Berkshire: NFER-Nelson.) while event-related potentials (ERPs) were recorded. Twelve subjects were instructed to feign a recognition memory deficit (malingering group), while the remainder served as controls. The malingerers performed poorly on the test compared to the control group. The 'old/new effect', an ERP measure thought to reflect recognition memory processes, did not differ between the groups, indicating recognition of previously learned material in the malingering group despite poor test performance. The study also revealed a second, early, old/new effect, maximal at left frontal sites in the malingering relative to the control group, suggesting task-related processing differences between the two groups. These effects appear to be of potential value in the detection of malingering of cognitive impairment in the clinical situation.     

The effect of depression and anxiety on the TOMM in community-dwelling older adults.

Tests of possible malingering are in increasing demand among neuropsychologists. The Test of Memory Malingering (TOMM) is resistant to many neurological conditions, including traumatic brain injury, dementia, and aphasia. Less clear is the impact of psychological conditions on TOMM performance. This study examined a sample of community-based older adults (55-75) to determine whether scores on the TOMM are influenced by the presence of symptoms of depression or anxiety, as measured by the Beck Depression Inventory (BDI) and State-Trait Anxiety Inventory (STAI), respectively. The results indicate that, regardless of BDI or STAI scores, all subjects scored above 45 correct out of 50 on TOMM Trial 2. These findings demonstrate that depression and anxiety levels in an older community-dwelling sample do not negatively affect performance on the TOMM.     

Is poor performance on recognition memory effort measures indicative of generalized poor performance on neuropsychological tests?

The detection of suboptimal effort has become crucial in clinical neuropsychological practice in order to make accurate diagnoses, prognoses, and referrals. Symptom Validity Testing (SVT) has been the most commonly utilized model for assessing effort, and frequently includes recognition memory tasks. Some conflicting views on this model purport, however, that measures of effort gathered from a recognition memory paradigm do not necessarily extend to effort in other cognitive domains and other areas of performance. The present study sought to investigate whether performance on an SVT measure, which utilizes recognition memory, the TOMM, could predict performance on other measures that do not evaluate recognition memory or just memory per se in a group of mildly traumatic brain-injured litigants. Results indicated that poor performance on the TOMM was significantly correlated with poorer performance on the WAIS-R and the HRNB-A. Further, experimental exploration of these results indicated that the overall neuropsychological performance of litigants with suboptimal effort was poorer than what is generally expected from mild TBI individuals, and was also lower than the other mild TBI examinees in the study, who were not classified by the TOMM as exhibiting suboptimal effort. These findings support the proposition that poor effort as measured by recognition memory effort measures is not restricted to recognition and memory measures. In fact, in the present study it appears that a poor performance on the TOMM is predictive of a generalized poorer performance on standardized measures such as the WAIS-R and the HNRB-A.     

Symptom validity testing of feigned amnesia for a mock crime.

Perpetrators sometimes claim loss of memory for the crimes they have committed. For the neuropsychologist, the veracity of such crime-related amnesia is difficult to assess. The aim of the present study was to investigate whether Symptom Validity Testing (SVT) can be used to detect feigning of crime-related amnesia. Undergraduate students (N = 39) were instructed to commit a mock crime and asked to feign complete amnesia for the event. Subsequently, they were given 25 forced-choice items about the "crime" that were always followed by the correct answer and an equally plausible alternative. To counteract chance performance, test items were intermixed with 25 bogus questions that contained two equally plausible alternatives. Results show that a majority of participants (59%) scored below chance level on the critical items of the SVT. In addition, debriefing interviews showed that understanding the rationale behind the SVT was not related to chance performance. SVT procedures therefore might be helpful in identifying feigned crime-related amnesia.     

Effects of coaching on detecting feigned cognitive impairment with the Category test.

In a replication and extension of previous research (Tenhula & Sweet, 1996), the current study investigated the utility of the Category Test (CT) for detecting feigned cognitive impairment. Ninety-two undergraduate participants were randomly assigned to one of three groups and administered the CT. A Coached Simulator group was instructed to simulate cognitive impairment and was provided test-taking strategies to avoid detection. An Uncoached Simulator group was simply instructed to feign impairment. A control group was instructed to perform optimally. In addition, the CT results of 30 traumatic brain injury (TBI) patients were analyzed. The results largely supported the utility of five CT malingering indicators identified by Tenhula and Sweet: (a) number of errors on subtests I and II, (b) number of errors on subtest VII, (c) total CT errors, (d) number of errors on 19 "easy" items, and (e) number of criteria exceeded. Correct Classification rates of the five indicators for Uncoached Simulators and optimal performance controls ranged from 87% to 98%. Correct Classification rates for the TBI patients ranged from 70% to 100%. In addition, significantly more Coached Simulators were misclassified as nonsimulators on four of the CT malingering indicators, relative to their Uncoached counterparts. A decision rule of > 1 error on subtests I and II was consistently the most accurate malingering indicator, regardless of degree of coaching or presence of TBI. This indicator correctly classified 76% of all simulators and 100% of the optimal performance controls and TBI patients. Implications of providing persons with test-taking strategies and the utility of these CT malingering indicators for various populations are discussed.     

Classification accuracy of the Test of Memory Malingering in persons reporting exposure to environmental and industrial toxins: Results of a known-groups analysis.

This study used a known-groups design to examine the classification accuracy of the Test of Memory Malingering in detecting cognitive malingering in patients claiming cognitive deficits due to exposure to environmental and industrial toxins. Thirty-three patients who met Slick et al. criteria for Malingered Neurocognitive Dysfunction were compared to 17 toxic exposure patients negative for evidence of malingering, 14 TBI patients and 22 memory disorder patients, both groups without incentive. The original cutoffs (<45) for Trial 2 and Retention demonstrated perfect specificity (0% false positive error rate) and impressive sensitivity (>50%). These findings indicate the TOMM can be used with confidence as an indicator of negative response bias in cases of cognitive deficits attributed to exposure to alleged neurotoxic substances.     

The use of all three Test of Memory Malingering trials in establishing the level of effort

Assessment of the effort level is an essential step in establishing the internal validity of any neuropsychological evaluation. The use of response bias measures as part of a core battery, however, is less common outside of forensic evaluations. The amount of time needed to administer many of these tests is often cited as a likely explanation for their exclusion from routine neuropsychological evaluations. This study examined all three trials of the Test of Memory Malingering (TOMM) in a large sample (n = 213) of inpatients on an epilepsy monitoring unit with the goal of establishing cut scores for early termination. TOMM Trial 1 demonstrated impressive diagnostic accuracy for determining both adequate and suboptimal levels of effort; various cut scores and classification statistics are presented. The optional Retention trial from the TOMM also increased the hit rate 16% in the detection of poor effort. Clinical implications, limitations, and directions for further research are discussed.     

A Psychophysiological Investigation of Short-Term Memory

Palmar skin conductance (SC), heart rate (HR), blink rate (BR), and peripheral pulse amplitude (PA) were monitored during a short-term memory (STM) task. Twenty male subjects were given 9 trials in which they were required to recall noun triads after 15 sec of interference (counting backwards). For half of the subjects (Nonshift group) all nouns in the experiment were from the same conceptual class, while the remaining subjects (Shift group) experienced two shifts in the taxonomic categories of the nouns, one on Trial 5 and another on Trial 9. There was a general decrease in recall performance over trials, the exceptions being an improvement in performance exhibited by the Shift group on Trials 5 and 9. The improved performance of the Shift group on Trial 5 was associated with marked HR deceleration during presentation of the nouns. Withinsubject comparisons revealed that during the 15-sec interference period recall performance was associated with physiological responsivity, with larger increases in SC, HR, BR, and peripheral vasoconstriction occurring on the “best” recall trials than on the “worst” trials. The results were interpreted in terms of the role of attention and effort in mediating STM.     

Ongoing Pain as a Mental Workload Indexed by P300 Depression: Discrimination of Real and Feigned Pain Conditions

Two groups of subjects were formed. One, a real pain group, was subjected to aversive pressure on the fingernail surface during pain-only and pain-tracking conditions. The second group (feigned pain) was instructed to feign pain during corresponding runs in which fingernail pressure was applied at a just noticeable (not painful) level. Both groups also simultaneously performed an auditory oddball (.8/.2) task during their pain-only and pain-tracking conditions, as well as during an initial (baseline-1) and final (baseline-2) baseline condition in which only the oddball task was performed. Oddball-evoked P300 amplitudes were significantly different for the groups during the pain-tracking and baseline-2 conditions, with the amplitudes smaller in the real pain groups in both conditions. The pain-only and pain-tracking conditions in both groups caused significant P300 reductions in comparison with baseline-1 values. P300 latencies did not differ as a function of either groups or conditions. 100% of the real pain subjects and 67% of the feigned pain subjects could be correctly classified using P300 amplitude-derived indices.