Validation of a New Technique to Detect Malingering of Cognitive Symptoms: The b Test

Archives of Clinical Neuropsychology, Vol. 15, No. 3, pp. 227–241, 2000 Copyright © 2000 National Academy of Neuropsychology Printed in the USA. All rights reserved 0887-6177/00 $–see front matter PII S0887-6177(99)00014-1 Validation of a New Technique to Detect Malingering of Cognitive Symptoms: The b Test Kyle Brauer Boone Harbor-UCLA Medical Center Po Lu Pepperdine University & Harbor-UCLA Medical Center Dale Sherman Harbor-UCLA Medical Center Barton Palmer Harbor-UCLA Medical Center Carla Back Harbor-UCLA Medical Center & California School of Professional Psychology Elias Shamieh California School of Professional Psychology Kimberly Warner-Chacon California School of Professional Psychology Nancy G. Berman Harbor-UCLA Medical Center We administered the b Test, a new measure to identify malingering requiring recognition of overlearned information, to 34 suspected malingerers and to 161 subjects in various clinical groups (moderate to severe head injury, elderly depressed, learning disability, schizophrenia, right and left CVA, and elderly normals). Comparisons of groups revealed more commission Address correspondence to: Kyle Boone, PhD, ABPP-ABCN, Box 495, Harbor-UCLA Medical Center, Department of Psychiatry, 1000 W. Carson Street, Bldg F-9, Torrance, CA, USA 90509-2910. 227 228 K. B. Boone et al. and omission errors in the suspected malingerers relative to all groups except the right stroke patients. In addition, suspected malingerers took longer to complete the task than all groups except right and left stroke patients and normal elderly. A cutoff of ⬎2 commission errors produced a sensitivity of 76.5% and specificity for all comparison groups combined of 82.6%. Lower sensitivity rates were documented for omissions (58.8 using cutoff of ⬎40) and time (57.6% using cutoff of ⬎12 minutes), but specificity remained high at 85.1% and 83.9%, respectively. Thus, the b Test shows considerable potential as a malingering detection tool. © 2000 National Academy of Neuropsychology. Published by Elsevier Science Ltd Within the past 10 years, numerous publications have emerged on the issue of the detection of malingered cognitive symptoms. This research has focused both on the identification of “malingering” patterns on standard cognitive measures, such as the Warrington Recognition Memory Test (Iverson & Franzen, 1994; Millis, 1992), Rey Auditory Verbal Learning Test (Barrash, Suhr, & Manzel, 1998; Bernard, Houston, & Natoli, 1993; Chouinard & Rouleau, 1997; Greiffenstein, Baker, & Gola, 1994; Suhr, Tranel, Wefel, & Barrash, 1997), Wechsler Memory Scale-Revised (Bernard, McGrath, & Houston, 1993; Iverson & Franzen, 1996; Martin, Franzen, & Orey, 1998; Mittenberg, Azrin, Millsaps, & Heilbronner, 1993), Wisconsin Card Sorting Test (Bernard, McGrath, & Houston, 1996), Stroop Test (Osimani, Alon, Berger, & Abarbanel, 1997), Digit Span (Binder & Willis, 1991; Greiffenstein, et al., 1994; Heaton, Smith, Lehman, & Vogt, 1978; Iverson & Franzen, 1994, 1996; Martin, Hayes, & Gouvier, 1996; Mittenberg, Theroux-Fichera, Zielinski, & Heilbronner, 1995; Suhr et al., 1997; Trueblood, 1994; Trueblood & Schmidt, 1993; Youngjohn, Burrows, & Erdal, 1995), Bender Gestalt (Schretlen, Wilkins, Van Gorp, & Bobholz, 1992), Ravens Standard Progressive Matrices (Gudjonsson & Schackleton, 1986), K-ABC hand movements (Bowen & Littell, 1997), Seashore Rhythm Test (Gfeller & Cradock, 1998), and finger tapping, grip strength, and grooved pegboard (Greiffenstein, Baker, & Gola, 1996), and also on development of tests specifically designed to detect faking, such as the Rey 15-item Memorization Test (Lezak, 1995), Rey Word Recognition Test (Lezak, 1983), Rey Dot Counting Test (Lezak, 1995), Portland Digit Recognition Test (PDRT; Binder, 1993), Hiscock Digit Memory Test (Hiscock & Hiscock, 1989), and Test of Memory Malingering (Rees, Tombaugh, Gansler, & Moczynski, 1998). These two approaches to the detection of malingering (Iverson & Franzen, 1996) have relied on the fact that the lay public as a group holds many inaccurate beliefs regarding the neuropsychological consequences of head injury (Gouvier, Prestholdt, & Warner, 1988; Willer, Johnson, Rempel, & Linn, 1993). In particular, the general population seems to assume that brain injury causes losses in recognition memory, basic attention span, overlearned information, and motor strength and dexterity, when in actuality, these domains are relatively preserved in all but the most severely brain injured patients (Baddeley & Warrington, 1970; Black, 1986; Heaton et al., 1978; Mittenberg, Rotholc, Russell, & Heilbronner, 1996; Rawling & Brooks, 1990; Rubinsky & Brandt, 1986; Wiggins & Brandt, 1988). This faulty knowledge base causes the malingerer to respond to tests measuring these skills in a manner at variance with that displayed by cooperative brain-injured patients; specifically, malingerers overplay deficits in these areas. The tests specifically designed to identify faking of cognitive symptoms have primarily focused on documenting feigned impairments in short term memory (e.g., PDRT, Hiscock Digit Memory Test, 15-item Memorization Test, Rey Word Recognition Test), although some tests have been developed to capture other feigned cognitive symptoms, such as malingered losses in mental speed/calculation ability (Dot Counting Test). One understudied area ripe for the development of malingering tests involves measurement Detection of Malingering with the b Test 229 of recognition of overlearned and highly familiar information. This type of knowledge is particularly resistant to brain injury as reflected by the fact that highly practiced skills, such as word reading, are relatively spared in acquired brain impairment, and in fact this is the rationale behind the use of word-reading tasks to assess premorbid level of function (Nelson & McKenna, 1975). Sparing of sight reading is also the mechanism on which the “Stroop effect” is based, namely, that in brain injury the patient has difficulty overriding this highly automatic behavior. The presence of relatively spared sight reading skills has been confirmed in patients with head injury (Crawford, Parker, & Besson, 1988), dementia (Crawford, Parker, & Besson, 1988; Nelson & McKenna, 1975), heterogenous cortical disease (Ruddle & Bradshaw, 1982), schizophrenia (Crawford, Besson, Bremner, Ebmeier, Cochrane, & Kirkwood, 1992), and depression (Crawford, Besson, Parker, Sutherland, & Keen, 1987). Thus, a malingering test constructed using this type of overlearned information should have a relatively low false positive rate in patients with actual cerebral dysfunction. At the same time, because the general public does not seem to be cognizant of the relative preservation of overlearned information in brain injury, the prospect of true positive identification of malingering is enhanced. Anecdotally, the first author has assessed several malingerers who have stated that they had become dyslexic ( (...truncated)