Zita Bouman1,2, Marc P H Hendriks1,2, Ben A Schmand3,4, Roy P C Kessels2,5, Albert P Aldenkamp1,6,7,8. 1. a Academic Centre for Epileptology , Kempenhaeghe , Heeze , the Netherlands. 2. b Donders Institute for Brain, Cognition and Behaviour, Radboud University , Nijmegen , the Netherlands. 3. c Department of Psychology , University of Amsterdam , Amsterdam , the Netherlands. 4. d Department of Medical Psychology , Academic Medical Center, University of Amsterdam , Amsterdam , the Netherlands. 5. e Department of Medical Psychology , Radboud University Medical Center , Nijmegen , the Netherlands. 6. f Department of Neurology , University Hospital Gent , Gent , Belgium. 7. g Signal Processing System Group, Faculty of Electrical Engineering , Technical University Eindhoven , Eindhoven , the Netherlands. 8. h Department of Neurology and School for Mental Health and Neuroscience , Maastricht University Medical Centre , Maastricht , the Netherlands.
Abstract
INTRODUCTION: Recognition and visual working memory tasks from the Wechsler Memory Scale-Fourth Edition (WMS-IV) have previously been documented as useful indicators for suboptimal performance. The present study examined the clinical utility of the Dutch version of the WMS-IV (WMS-IV-NL) for the identification of suboptimal performance using an analogue study design. METHOD: The patient group consisted of 59 mixed-etiology patients; the experimental malingerers were 50 healthy individuals who were asked to simulate cognitive impairment as a result of a traumatic brain injury; the last group consisted of 50 healthy controls who were instructed to put forth full effort. RESULTS: Experimental malingerers performed significantly lower on all WMS-IV-NL tasks than did the patients and healthy controls. A binary logistic regression analysis was performed on the experimental malingerers and the patients. The first model contained the visual working memory subtests (Spatial Addition and Symbol Span) and the recognition tasks of the following subtests: Logical Memory, Verbal Paired Associates, Designs, Visual Reproduction. The results showed an overall classification rate of 78.4%, and only Spatial Addition explained a significant amount of variation (p < .001). Subsequent logistic regression analysis and receiver operating characteristic (ROC) analysis supported the discriminatory power of the subtest Spatial Addition. A scaled score cutoff of <4 produced 93% specificity and 52% sensitivity for detection of suboptimal performance. CONCLUSION: The WMS-IV-NL Spatial Addition subtest may provide clinically useful information for the detection of suboptimal performance.
INTRODUCTION: Recognition and visual working memory tasks from the Wechsler Memory Scale-Fourth Edition (WMS-IV) have previously been documented as useful indicators for suboptimal performance. The present study examined the clinical utility of the Dutch version of the WMS-IV (WMS-IV-NL) for the identification of suboptimal performance using an analogue study design. METHOD: The patient group consisted of 59 mixed-etiology patients; the experimental malingerers were 50 healthy individuals who were asked to simulate cognitive impairment as a result of a traumatic brain injury; the last group consisted of 50 healthy controls who were instructed to put forth full effort. RESULTS: Experimental malingerers performed significantly lower on all WMS-IV-NL tasks than did the patients and healthy controls. A binary logistic regression analysis was performed on the experimental malingerers and the patients. The first model contained the visual working memory subtests (Spatial Addition and Symbol Span) and the recognition tasks of the following subtests: Logical Memory, Verbal Paired Associates, Designs, Visual Reproduction. The results showed an overall classification rate of 78.4%, and only Spatial Addition explained a significant amount of variation (p < .001). Subsequent logistic regression analysis and receiver operating characteristic (ROC) analysis supported the discriminatory power of the subtest Spatial Addition. A scaled score cutoff of <4 produced 93% specificity and 52% sensitivity for detection of suboptimal performance. CONCLUSION: The WMS-IV-NL Spatial Addition subtest may provide clinically useful information for the detection of suboptimal performance.