Information/Orientation Subtest of the Wechsler Memory Scale-Revised as an Indicator of Suspicion of Insufficient Effort*

Transcription

1 The Clinical Neuropsychologist /00/ $ , Vol. 14, No. 1, pp Swets & Zeitlinger Information/Orientation Subtest of the Wechsler Memory Scale-Revised as an Indicator of Suspicion of Insufficient Effort* Yana Suchy 1 and Jerry J. Sweet 1, 2 1 Evanston Hospital and 2 Northwestern University Medical School ABSTRACT The utility of the Information/Orientation (IO) subtest of the Wechsler Memory Scale-Revised in identifying insufficient effort was examined. Performances of 50 benefit-seeking patients were compared to previously generated rms based on a clinical sample. Of the 50 benefit-seeking patients, 6 (12%) had IO scores that were outside the performance ranges of the entire clinical sample. An additional 6 of 50 (24%) had performances that were comparable to less than 2% of the rmative sample. These results are consistent with previously published estimates of insufficient effort base rates in benefit-seeking populations and demonstrate the utility of IO as an indicator of suspicion of insufficient effort. Assessment of effort and motivation to perform poorly or well (hereafter referred to as effort ) has become a standard component of neuropsychological evaluations, especially in situations in which poor performance will result in benefit or gain. When assessing effort, clinicians face a number of challenges. First, measures used for effort assessment often have low sensitivity. This is related to several factors, including the fact that most malingerers are t likely to perform below their true ability on all administered measures (Goebel, 1983), and that some may opt to generate long response latencies or exhibit psychological distress, rather than make errors (Beetar & Williams, 1995; Iverson, 1995; Tenhula & Sweet, 1996). Additionally, sensitivity is directly related to the stringency of utilized cutoffs, which in turn reflect whether loss in specificity is acceptable to a given clinician. Given that low specificity (i.e., misidentification of n-malingerers as malingerers) amounts to accusing patients with bona fide deficits of criminal acts (e.g., fraud, perjury), many clinicians prefer to decrease sensitivity in favor of increasing specificity (Sweet, 1999, p. 258). However, true sensitivity in the real world is virtually impossible to determine, as at least some true malingerers likely go undetected (Faust, Hart, & Guilmette, 1988; Heaton, Smith, Lehman, & Vogt, 1978). The second challenge in effort assessment is that, as neuropsychologists become more sophisticated at identifying insufficient effort or malingering, their clients, too, become increasingly sophisticated at feigning deficits in a more realistic fashion. In fact, in some cases clients may even be coached by their attorneys (Youngjohn, 1995). Finally, because clinicians need to consider multiple measures of effort and ability in their assessment, there is the additional challenge of performing the assessment within reasonable time limits. The challenges in effort assessment may best be addressed by identifying complex performance patterns within commonly used measures of ability, especially if such patterns defy (mis) * Address correspondence to: Yana Suchy, Neuropsychology Service, Department of Psychiatry, Evanston Northwestern Healthcare, 2650 Ridge Avenue, Evanston, IL USA. yana.suchy@prodigy.net. Accepted for publication: November 25, 1999.

2 INFORMATION/ORIENTATION AS AN INDICATOR OF SUSPICION 57 conceptions held by the general public about the effects of brain dysfunction on a particular cognitive domain (e.g., for common misconceptions about memory, see Wiggins & Brandt, 1988). Characterization of such patterns potentially affords development of multiple indices of effort within a given battery of ability measures, thereby reducing the need to administer additional time-consuming tasks. This approach may also provide a further safeguard against coaching, as evaluation of effort within actual ability measures can be based on complex rmative tables and contain multiple moderator variables, such as age and education. Examples of the use of performance patterns include characterization of differential performance on easy and difficult items of the Booklet Category Test (Bolter, Pica, & Zych, 1985; Tenhula & Sweet, 1996), or comparison of performances on Vocabulary and Digit Span subtests of the Wechsler Intelligence Scale-Revised (Millis & Ross, 1996; Mittenberg, Theroux-Richera, Zielinski, & Heilbronner, 1995). Within widely used memory measures, examples include characterization of profiles of four memory indices from the California Verbal Learning Test (e.g., Millis & Putnam, 1997; Millis, Putnam, Adams, & Ricker, 1995), or comparison of General Memory and Attention/Concentration indices from the Wechsler Memory Scale-Revised (WMS-R: Mittenberg, Azrin, Millsaps, & Heilbronner, 1993). The success of these approaches in separating neurologic profiles from insufficient effort served as a springboard for the present study. The purpose of the present study was to determine whether recently generated rmative tables for Information/Orientation (IO) scores from the Wechsler Memory Scale-Revised (WMS-R) (Sweet, Suchy, Leahy, Abramowitz, & Nowinski, in press) could be used for identification of infrequent performance patterns that may serve to raise suspicion regarding insufficient effort. The attractiveness of these tables for assessment of effort lies in the fact that they consider three moderator variables (age, and performances on the Visual Reproduction II and Logical Memory II subtests of the WMS-R). The inclusion of these moderator variables would likely make feigning of a realistically impaired performance difficult without access to the actual testing materials and rmative data. These rmative tables were based on a sample that was free of individuals seeking a benefit or compensation. The IO subtest of the WMS-R contains orientation questions, as well as questions about autobiographical information (e.g., age, date of birth). The possibility that some benefit-seeking individuals may choose to feign impairments on these items is suggested by prior research that has shown that individuals simulating brain dysfunction may fail autobiographical questions (Rosenfeld, Ellwanger, & Sweet, 1995; Wiggins & Brandt, 1988). Although many clinicians are w making the transition to the more recent third edition of the Wechsler Memory Scale, the WMS-III, the results of the present study can be generalized to this newer version, as the IO subtest has t changed at all and the memory variables are expressed as T scores, rather than raw scores, and remain virtually unchanged conceptually. Additionally, WMS-R may continue to be used by some clinicians for some time yet, in particular in legal settings when considerable expertise with any given instrument is required. In order to determine the effectiveness of IO performance in detecting insufficient effort, IO scores in a sample of individuals whose evaluations occurred within the context of possible benefit-seeking were compared to those in a rmative clinical sample. IO scores that were significantly below the scores observed in the rmative clinical sample were deemed to indicate a red flag for insufficient effort. As prior research has estimated that base rates of insufficient effort on neuropsychological testing among benefit-seeking populations range from 7.5% to 33% (Binder, 1993; Frederick, Sarfaty, Johnston, & Powel, 1994; Trueblood & Schmidt, 1993), it was hypothesized that unusually low performance on IO would be found in a comparable proportion of the present benefit-seeking sample.

3 58 YANA SUCHY AND JERRY J. SWEET METHOD Participants Participants consisted of 50 benefit-seeking patients (34 male and 16 female) referred to Evanston Hospital Neuropsychology Service for neuropsychological evaluations. Benefit-seeking was defined as any circumstance in which poor performance on neurocognitive measures could potentially lead to obtaining, or maintaining, a direct benefit, whether as a lump-sum, or in the form of a disability or social-security income. In the present sample, 44 patients were referred for neuropsychological evaluations for the purpose of providing an independent opinion pertaining to litigated claims of damages or disability claims, and 3 patients were referred for assessment of whether continuation of disability benefits was warranted. For the 3 remaining patients, the presence of benefit-seeking issues was indicated in the available records and in the database, although the exact circumstances of the referral could t be determined in retrospect. The patients ranged in age from 20 to 77 years (M = 43.28, SD = 13.62) and had between 9 and 20 years of education (M = 13.70, SD = 2.62). Forty patients had presumably suffered a traumatic brain injury (), 3 had suffered solvent exposures, 3 had suffered an axic event, 2 had had cerebrovascular accidents, 1 had suffered an electrical injury, and one presented with depression. As a validation of the presence of varying degrees of effort among the present sample, the frequency of participants performances that were below previously established cut-offs on available indices of insufficient effort are presented in Table 1. Specifically, the following performances were considered to represent positive evidence for insufficient effort if they were below empirically established cut-offs based on prior research: Multi Digit Memory Test (MDMT; Martin, Bolter, Todd, Gouvier, & Niccolls, 1993); California Verbal Learning Test (CVLT) recognition score, and trials 1 through 5 total (Millis et al., 1995; Sweet et al., in press); Booklet Category total errors, total errors from subtests I and II, number of errors from subtest VII, and number of errors on easy items (Tenhula & Sweet, 1996); and Rey Memory Fifteen Item Test (MFIT) number of correct rows (Arnett, Hammeke, & Schwarz, 1995). Note that the above indices were examined only for the 40 patients with traumatic brain injury because these measures have t been validated for other populations. As previously recommended (Ben-Porath, 1994), the specific cut-offs are t presented here in order to protect the findings of malingering research against coaching by n-psychologists. Procedure Raw IO scores in the present sample were compared to those obtained by a rmative clinical sample of 312 individuals (Sweet et al., in press). Demographic and diagstic characteristics of the rmative sample were comparable to those of the present sample. Specifically, the rmative sample consisted of 312 individuals (162 males and 150 females) referred to the Evanston Hospital Neuropsychology Service for clinical assessment. They Table 1. Frequency of Failed Insufficient Effort Indices among 40 Participants with Traumatic Brain Injury in the Present Benefit-Seeking Sample. Insufficient Effort Index Available protocols Percent failed MDMT total correct Rey MFIT rows CVLT five trial total recognition Booklet Category subtests I&IItotal subtest VII total errors easy item errors Bolter items errors Note. MDMT = Multi Digit Memory Test; CLVT = California Verbal Learning Test; MFIT = Memory for Fifteen Items Test.

4 INFORMATION/ORIENTATION AS AN INDICATOR OF SUSPICION 59 ranged in age from 17 to 92 years (M = 55.5, SD = 17.7) and had 8 to 23 years of education (M = 14.7, SD = 2.7). Diagses included cerebral vascular accident (n = 64), traumatic brain injury (50), probable Alzheimer s Disease (35), Parkinson s Disease (25), intracranial neoplasm (21), seizure disorder (12), multiple sclerosis (3), and other degenerative dementias (3). Additionally, 52 patients had multiple neurological conditions or had cognitive impairment as a result of less frequent conditions in our referral base, such as encephalitis, lupus erythematosus, and HIV. Ather 28 individuals had neurological disorders for which a specific etiological condition could t be identified. Of the remaining 19 patients, 14 met DSM criteria for major depression and 5 neurologically rmal individuals had n-psychotic psychological conditions for which more specific diagses could t be identified. The rmative tables that are based on this sample are organized by age and performances on the Visual Reproduction II (VRII) and Logical Memory II (LMII) subtests of the WMS-R. The actual ranges of scores obtained by participants in the rmative sample (hereafter referred to as Liberal Ranges ) are summarized in the flowchart in Figure 1, and are presented as values in dark gray rectangles on the right-hand side of the chart under the heading IO Raw Scores (values presented in white diamonds will be discussed later in this section). When following the flowchart, readers should start in the upper left-hand corner. The first row of the flowchart indicates that, for those rmative sample participants who had VRII or LMII T scores above 60, IO raw scores ranged from 13 to 14 (T scores were generated by a standard conversion from percentile values available in the WMS- R manual; Wechsler, 1987). It can also be gleaned from the first row of the chart that VRII or LMII T scores above 60 were present in 47 of the 312 rmative sample participants (this value is presented in parentheses in the dark gray rectangle). Following the flowchart further, it can be seen that age became an important moderator variable for those rmative sample participants whose VRII or LMII T scores were t above 60. For example, the second row of the flowchart shows that, for participants whose VRII or LMII T scores were t above 60 and whose ages were below 46, raw IO scores ranged from 10 to 14. Subsequent branches of the flowchart indicate IO performance ranges for the remainder of the rmative sample. Note that the Liberal Ranges characterize the entire clinical rmative sample. In other words, participants in the rmative sample had IO scores outside the Liberal Ranges, implying 100% specificity. The numbers of patients in each branch of the flowchart are presented in parentheses under each IO range. The correspondence of the flowchart with the rmative tables was evaluated by five graduate students who were otherwise t involved in this study. An examination of frequency distributions of scores in the rmative sample further revealed that certain rmative participants exhibited somewhat outlying IO scores. Specifically, among rmative sample participants whose memory T scores were t above 60 and whose ages were below 46 (see the second row of the flowchart), only 5 had an IO score below 12. Additionally, only 1 patient in the 49-to-69 age range with at least one average memory performance (i.e., T score between 40 and 60) had an IO score below (see the third row of the flowchart). These 6 participants represent only 1.9% (i.e., 6 of 312) of the rmative sample, and from that perspective their IO scores appear to be unusually low. For this reason, where appropriate, IO scores of individuals in the present benefit-seeking sample were also compared to Constricted Ranges (presented in Figure 1 as values in white diamonds, where appropriate). These ranges simply indicate that, among individuals below age 45, IO scores below 12 are highly unusual, and, among individuals between the ages 49 and 69 who have at least one average memory performance, IO scores below are also highly unusual. For both the Liberal Ranges and the Constricted Ranges, the incidence of unusual profiles (i.e., IO scores outside of the ranges indicated in Figure 1) among the benefit-seeking patients was calculated. The number of profiles outside of the Liberal Ranges and the Constricted Ranges were compared to each other to determine which set of ranges would have better diagstic utility. In order to investigate potential causes of unusual IO scores other than insufficient effort, available records of all participants with unusual IO scores were carefully examined. Particular attention was paid to the presence of factors that would affect clinical decision-making with respect to effort, such as time since injury, results of neuroimaging studies, and environmental factors during testing. Additionally, when available, other indices of effort were examined. Formal statistical evaluation of these results was t conducted because of variability among test batteries used in individual cases.

5 60 YANA SUCHY AND JERRY J. SWEET MEMORY T-SCORES AGE (in years) IO RAW SCORES START HERE VRII or LMII > to 14 (n=47) Age below to 14 (n=72) 12 to 14 (n=67) VRII or LMII to 60 Age 46 to 69 9 to 14 (n=79) to 14 (n=78) Age > 69 7 to 14 (n=43) VRII or LMII 30 to 39 Age 46 to 69 8 to 13 (n=25) Age > 69 4 to 14 (n=29) VRII and LMII < 30 3 to 14 (n=17) Fig. 1. Flowchart summarizing the expected ranges of IO scores associated with patients ages and Logical Memory II or Visual Reproduction II T scores, derived from a rmative sample of 312 clinical referrals.

6 INFORMATION/ORIENTATION AS AN INDICATOR OF SUSPICION 61 RESULTS Liberal Ranges In the present benefit-seeking sample, 6 (i.e., 12 %) out of 50 individuals had IO scores that were outside of the Liberal Ranges (i.e., outside of the entire rmative sample). Of these 6, 5 were in litigation and 1 was seeking benefit, the exact nature of which could t be determined in retrospect. Constricted Ranges An additional 6 of 50 (i.e., 12%) benefit-seeking participants had IO scores outside of the Constricted Ranges, which, combined with the frequency outside the Liberal Ranges, is a total of 24% of the benefit-seeking sample demonstrating unusually poor profiles. Of these additional 6 patients, 5 were in litigation and 1 was assessed to determine readiness to return to work following a period of disability. In contrast, only 6 of 312 (i.e., 1.9%) of the rmative sample had IO scores outside of the Constricted Ranges. Although true sensitivity of this approach cant be determined because the actual incidence of insufficient effort in this sample is t kwn, the present result is consistent with previously reported insufficient effort base rates among benefit-seeking populations (Binder, 1993; Frederick et al., 1994; Trueblood & Schmidt, 1993). Review of Normative Sample Records Available records for the 6 rmative sample cases who had unusual IO scores were also examined. This review revealed that 5 of the 6 patients had identifiable, legitimate, neurological explanations for their poor IO performances. Specifically, 2 of these cases were inpatients recovering from acute neurologic conditions (i.e., 2 weeks status post status epilepticus superimposed on multiple sclerosis exacerbation; and 3 weeks status post cerebrovascular accident superimposed on radiation necrosis and residual neoplasm); 1 was 6 weeks status post mild traumatic brain injury associated with seizure activity; 1 was a case of an early onset Alzheimer s Disease (meeting criteria established by the National Institute of Neurological and Communicative Disorders [NINCD] and the Alzheimer s Disease and Related Disorders Association; McKhann et al., 1984); and 1 was assessed following recovery from encephalitis with significant neurologic sequelae confirmed by abrmal CT, MRI, and EEG results. The sixth patient had recovered from viral encephalitis and, in addition to continued neurocognitive deficits, exhibited poor cooperation during testing, apparently due to personality characteristics, which may have resulted in less than optimal effort. Review of Benefit-Seeking Sample Records The characteristics of the 12 benefit-seeking patients whose IO scores were unusually low are summarized in Table 2. Of these 12 patients, 2 had histories suggesting that their performances may have been unusually low for reasons other than insufficient effort. In one case, an individual (#4 in Table 2) with frank memory limitations was brought by her attorney from ather state. This patient erroneously referred to the town in which testing took place as Chicago, when in fact she was in Evanston, a town in the Chicago area. Additionally, this patient did t kw the name of the hospital (Evanston Hospital). It is conceivable that these two errors would t have been committed had this patient been familiar with the geographical area in which testing took place, in which case her performance would have been within rmal limits. Additionally, a review of this patient s file did t indicate any other suspicious or unusually low performances. For these reasons, the suspicion regarding effort raised by low IO scores can be disregarded in this case. The second individual (#5 in Table 2) whose poor IO performance was deemed possibly legitimate had suffered a documented mild traumatic brain injury in a motor vehicle accident 5 weeks previously. Although some patients recover fully within such a time period, a more commonly used upper limit for resolution of symptoms of a mild head injury is 3 months (Levin et al., 1987). Because once again there were other indicators of insufficient effort within this patient s file, it was determined that the benefit of the doubt was in order in this case.

7 62 YANA SUCHY AND JERRY J. SWEET Table 2. Demographic and Psychometric Characteristics of Patients with Secondary Gain who Exhibited Unusually Poor Information-Orientation Profiles. Patient # Age Educ. VRII T LMII T IO Other FAILED Effort Indices Other PASSED Effort Indices Etiology * 6* 9* 10* * 12* CVLT total = 26 CVLT recognition = 12 MDMT = 39/72 MFIT rows = 0 CVLT total = 41 CVLT recognition = 12 ne ne t applicable ne ne CVLT total = 41 MDMT = 35/72 CVLT total = 31 Category total = 96 Category VII = 6 Category easy errors = 4 CVLT total = 41 CVLT recognition = 10 Category VII = 6 CVLT total = 34 None administered MFIT items, CLVT, Category Category MDMT, MFIT, CVLT, Category MDMT, MFIT, CVLT, Category t applicable CVLT, Category CVLT, Category MDMT, MFIT, CVLT recognition, Category CVLT recognition, MFIT Category, CVLT, MDMT, MFIT Category, CVLT, MDMT /Out of town /Five weeks post MVA axia Note. Educ. = years of education; VRII T= Visual Reproduction II T score; LMII T = Logical Memory II T score; MDMT= Multi Digit Memory Test; CLVT = California Verbal Learning Test; MFIT = Memory for Fifteen Items Test; = traumatic brain injury. * IO performances that were outside of the Liberal Ranges.

8 INFORMATION/ORIENTATION AS AN INDICATOR OF SUSPICION 63 Review of available records of the remaining 10 benefit-seeking patients whose IO performances were identified as unusually poor did t reveal any neurologic conditions or environmental variables that could explain their poor performances. Overall, of the 10 patients, 2 exhibited one other positive clinical indicator of insufficient effort, 3 exhibited two other positive clinical indicators of insufficient effort, 1 had three other indicators, and 1 patient had five other indicators. For 2 of these 10 patients, indicators of insufficient effort, other than unusual IO scores, were found in their profile. Finally, 1 patient (#6 in Table 2) had suffered axia, rather than, and for this reason effort indices were t applicable in this case. Taken together, these results demonstrate that the sensitivity of IO as a red flag for insufficient effort improves when Constricted Ranges are used, with practical loss of specificity. In other words, less than 2% of clinical referrals performed outside of these ranges, and these consisted primarily of patients with independently confirmed serious neurologic findings for whom assessment of poor effort due to benefitseeking is typically t an issue. DISCUSSION The present study demonstrates the utility of the IO subtest from the WMS-R as a potential indicator of insufficient effort or malingering among patients for whom benefit-seeking issues could be identified. Specifically, when IO performances among benefit-seeking patients were compared to those among the clinical rmative sample, 10 of 50 benefit-seeking patients (i.e., 20%) were identified as likely exhibiting some degree of insufficient effort. Suspicion was raised, but insufficient effort was ruled out regarding 2 of the 50 (i.e., 4%) patients. In contrast, suspicion was raised in only 6 of 312 (i.e., 1.9%) of the clinical patients, with insufficient effort able to be ruled out easily in 5 of the 6 due to neurologic conditions being present. The sixth patient exhibited poor cooperation during testing, and his effort was, in fact, questionable due to psychological/personality issues. These results support the use of an unusual IO performance as a red-flag regarding insufficient effort, which should then be further investigated. In order to evaluate the appropriateness of more versus less stringent cut-offs, the present study identified insufficient effort by comparing IO performances of the present sample to two sets of rmative ranges: (a) the Liberal Ranges, which reflect the range of performance of the entire rmative sample, and (b) the Constricted Ranges, which reflect the range of performance of 98.1% of the rmative sample. The results demonstrate that the use of Constricted Ranges yields better sensitivity, with real practical decrease in specificity. In other words, Constricted Ranges yielded better sensitivity by identifying twice as many suspicious profiles among benefit-seeking patients as did the Liberal Ranges. In addition, Constricted Ranges also identified one rmative sample patient who was t fully cooperative during testing due to personality issues. Although the use of Constricted Ranges also led to incorrect suspicion regarding 5 of the 312 clinical patients, specificity did t suffer because, as ted earlier, review of patient records revealed that these 5 patients had acute or severe neurological dysfunctions that were independently verifiable and capable of producing their performances. In other words, given their clinical circumstances, these patients would t be misclassified as exhibiting insufficient effort despite poor IO performances. Although the numbers of patients red-flagged by the present method is consistent with insufficient effort base-rate estimates reported in the literature (Binder, 1993; Frederick et al., 1994; Trueblood & Schmidt, 1993), the exact sensitivity is t possible to determine as true incidence of insufficient effort in this sample (or in any clinical sample) is t kwn. Additionally, as each individual patient who malingers or exhibits insufficient effort may use different strategies or rely on a different set of misconceptions about brain dysfunction, it is highly unlikely that all persons with insufficient effort would perform outside of rmal ranges on IO. In fact, an examination of red-flagged patients performances on other available indicators of insuffi-

9 64 YANA SUCHY AND JERRY J. SWEET cient effort confirms this interpretation. Of the 7 individuals who exhibited suspicious performances on other measures (see Table 2, column Other Failed Effort Indices for patients number 1, 2, 3, 9, 10,, & 12), 6 performed within rmal limits on a number of other insufficient effort indices (patient #1 did t have other indices available; see Table 2, column Other Passed Effort Indices ). Specifically, considering the performances of the 7 patients on MDMT, MFIT, two CLVT indices (total and recognition), and four Booklet Category indices (total errors, total errors on subtests I and II, total errors on subtest VII, and total easy item errors), these patients performed within previously established rmal limits on a total of 25 other indices (3.6 per patient on average). This observation suggests that one index of insufficient effort may be highly sensitive, and that a multitude of indices may need to be examined with any given patient. This high variability among patients performances can also be seen in Table 1, which shows frequencies with which individual effort indices were failed in the present sample. The need to use multiple strategies to identify insufficient effort and possible malingering has been stressed repeatedly in the relevant literature (Nies & Sweet, 1994; Sweet, 1999). A question remains as to whether the present method may have flagged some of the benefitseeking sample patients incorrectly as exhibiting insufficient effort. Because hard evidence of feigning, such as a less-than-chance performance on a forced choice test, is rarely available in most clinical situations (and did t occur in the present sample), answering this question can only be accomplished by inferential means. Specifically, in the present study, patients were inferred to exhibit insufficient effort or malingering if they met three criteria: (a) the absence of clinical circumstance that could account for unusually poor performance, (b) seeking of a reward that is contingent on a poor performance, and (c) performing more poorly on IO than patients t seeking rewards. It could, of course, be argued that causes other than insufficient effort may be responsible for poor performances under these circumstances. However, in the very least, confluence of the three criteria suggests that a relationship exists between poor performance and the reward contingency. In the present benefit-seeking sample, 10 of 50 participants (i.e., 20%) met these criteria. Of te is that 3 of the benefit-seeking patients who met all three of the above criteria otherwise performed within rmal limits on other available indicators of insufficient effort. Although this result may simply represent yet ather instantiation of the inconsistency and variability in performances among persons with insufficient effort, it also suggests that single unusual performances may be more likely to occur in the context of seeking compensation/benefit than in other clinical settings. The simple fact that these unusual performances occur within otherwise apparently valid profiles suggests that they may have occurred due to purposeless effort fluctuations, which may represent a symptom of as yet t fully understood psychological or psychiatric sequelae of undergoing litigation. The results of the present study have both clinical and theoretical implications. First on a clinical level, the results support the utility of the rmative tables generated by Sweet et al. (in press) for identification of unusual performances that may occur due to insufficient effort. The fact that these tables include three moderator variables (i.e., LMII, VRII, and age) represents an important advance and may lend new direction to future rmative studies. The present results further demonstrate that the presence of one, or even several, rmal performances on indices of insufficient effort does t adequately rule out an unusual, n-neurologic profile in a benefit-seeking patient. Rather, it may simply indicate that the test taker, if in fact feigning deficits, is sophisticated. In contrast, deficient performances on all indices may indicate an unsophisticated, naive malingerer. Future research may attempt to investigate whether a ratio of failed to n-failed measures of effort may help predict the proportion of common clinical measures of ability on which feigning of deficits occurred. Additionally, future research may investigate whether a relationship exists between the types of effort measures that are failed by a given patient and the types of measures of abil-

10 INFORMATION/ORIENTATION AS AN INDICATOR OF SUSPICION 65 ity on which feigning of deficits occurred. Finally, as caution needs to be exercised when generalizing these results to populations in other geographical regions or in different clinical settings, perhaps more extensive rms need to be developed. As mentioned above, one of the limitations of the present study is that the generalizability of the rmative sample to other populations is t clear at this time. Similarly, the generalizability of the results obtained from the present benefitseeking sample to other benefit-seeking populations is t clear, as the levels of sophistication among individuals who feign deficits is likely to vary. In addition, it needs to be ted that the utility of the present method seems to be limited to young and middle-aged patients, as clinical IO ranges among patients above the age of 70 are too broad for use in identifying poor effort. Finally, individuals who feign deficits in a consistent manner (i.e., feign very poor performance both on visual and auditory memory and on the IO subtest) would t be detected by the present method. REFERENCES Arnett, P., Hammeke, T., & Schwartz, L. (1995). Quantitative and qualitative performance on Rey s 15-items test in neurological patients and dissimulators. The Clinical Neuropsychologist, 9, Beetar,J., & Williams, J. (1995). Malingering response styles on the Memory Assessment Scales and symptom validity tests. Archives of Clinical Neuropsychology, 10, Ben-Porath, Y. (1994). The ethical dilemma of coached malingering research. Psychological Assessment, 6, Binder, L. (1993). Assessment of malingering after mild head trauma with the Portland Digit Recognition Test. Journal of Clinical and Experimental Neuropsychology, 15, Bolter, J.F., Pica, J.J., & Zych, K. (1985). Item error frequencies on the Halstead Category Test: An index of performance validity. Paper presented at the annual meeting of the National Academy of Neuropsychology, Philadelphia, PA. Faust, D., Hart, K., & Guilmette, T.J. (1988). Pediatric malingering: The capacity of children to fake believable deficits on neuropsychological testing. Journal of Consulting and Clinical Psychology, 56, Frederick, R., Sarfaty, S., Johnston, J.D., & Powel, J. (1994). Validation of a detector of response bias on a forced-choice test of nverbal ability. Neuropsychology, 8, Goebel, R. (1983). Detection of faking on the Halstead-Reitan Neuropsychological Test Battery. Journal of Clinical Psychology, 39, Heaton, R.K., Smith, H.H. Jr., Lehman, R.A.W., & Vogt, A.J. (1978). Prospects for faking believable deficits on neuropsychological testing. Journal of Consulting and Clinical Psychology, 46, Iverson, G. (1995). Qualitative aspects of malingered memory deficits. Brain Injury, 9, Levin, H.S., Mattis, S., Ruff, R., Eisenberg, H.M., Marshall, L.F., Tabaddor, K., High, W.M., & Frankowski, R.F. (1987). Neurobehavioral outcome following mir head injury: A three-center study. Journal of Neurosurgery, 66, Martin, R., Bolter, J., Todd, M., Gouvier, W.D., & Niccolls, R. (1993). Effects of sophistication and motivation on the detection of malingered memory performance using a computerized forced-choice task. Journal of Clinical and Experimental Neuropsychology, 15, McKhann, G., Drachman, D., Folstein, M., Katzman, R., Price, D., & Stadlan, E.M. (1984). Clinical diagsis of Alzheimer s disease: Report of the NINCDS-ADRDA Work group under the auspices of Department of Health and Human Services Task Force on Alzheimer s disease. Neurology, 34, Millis, S., Putnam, S., Adams, K., & Ricker, J. (1995). The California Verbal Learning Test in the detection of incomplete effort in neuropsychological evaluation. Psychological Assessment, 7, Millis, S., & Putnam, S. (1997). The California Verbal Learning Test in the assessment of financially compensable mild head injury: Further developments. Journal of the International Neuropsychological Society, 3, Millis, S., & Ross, S. (1996). Dissimulation indices of the Wechsler Adult Intelligence Scale-Revised: A replication and extension. Presented at the European Meeting of the International Neuropsychological Society, Veldhoven, Netherlands. Mittenberg, W., Azrin, R., Millsaps, & Heilbronner, R. (1993). Identification of malingered head injury on the Wechsler Memory Scale-Revised. Psychological Assessment, 5, Mittenberg, W., Theroux-Fichera, S., Zielinski, R., & Heilbronner, R. (1995). Identification of malingered head injury on the Halstead-Reitan Neuropsychological Battery. Archives of Clinical Neuropsychology,, Nies, K., & Sweet, J.J. (1994). Neuropsychological assessment and malingering: A critical review of past and present strategies. Archives of Clinical Neuropsychology, 9,

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