Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV) processing speed scores as measures of noncredible responding: The third generation of embedded performance validity indicators.

Abstract

Research suggests that select processing speed measures can also serve as embedded validity indicators (EVIs). The present study examined the diagnostic utility of Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV) subtests as EVIs in a mixed clinical sample of 205 patients medically referred for neuropsychological assessment (53.3% female, mean age = 45.1). Classification accuracy was calculated against 3 composite measures of performance validity as criterion variables. A PSI ≤79 produced a good combination of sensitivity (.23-.56) and specificity (.92-.98). A Coding scaled score ≤5 resulted in good specificity (.94-1.00), but low and variable sensitivity (.04-.28). A Symbol Search scaled score ≤6 achieved a good balance between sensitivity (.38-.64) and specificity (.88-.93). A Coding-Symbol Search scaled score difference ≥5 produced adequate specificity (.89-.91) but consistently low sensitivity (.08-.12). A 2-tailed cutoff on the Coding/Symbol Search raw score ratio (≤1.41 or ≥3.57) produced acceptable specificity (.87-.93), but low sensitivity (.15-.24). Failing ≥2 of these EVIs produced variable specificity (.81-.93) and sensitivity (.31-.59). Failing ≥3 of these EVIs stabilized specificity (.89-.94) at a small cost to sensitivity (.23-.53). Results suggest that processing speed based EVIs have the potential to provide a cost-effective and expedient method for evaluating the validity of cognitive data. Given their generally low and variable sensitivity, however, they should not be used in isolation to determine the credibility of a given response set. They also produced unacceptably high rates of false positive errors in patients with moderate-to-severe head injury. Combining evidence from multiple EVIs has the potential to improve overall classification accuracy. (PsycINFO Database Record

Single-neuronal predictions of others’ beliefs in humans

“…Prior to consideration, candidates for the study were evaluated by a multidisciplinary team of neurologists, neurosurgeons, and neuropsychologists 31 – 34 and decisions for surgery were unrelated to study participation. Prospective candidates who displayed cognitive scores that lay outside 1.5 standard deviations of their age-defined means (e.g., WAIS-IV, WCST, and WMS-IV) were excluded 35 , 36 . Consideration for inclusion in the study was only made after patients were scheduled for elective placement of deep brain stimulation.…”

Performance validity test failure in clinical populations—a systematic review

“…30 Erdodi et al reported high failure rates on validity indices derived from the Wechsler Adult Intelligence Scale (WAIS). 31 A study reporting validity test performance after stroke with initial aphasia found low failure rates on the (standard, pictorial) TOMM measures (7% (1/15 failing trial 2 and 0 failing the retention trial, but high failure rates on the Rey 15-item, RDS (<7) and reliable spatial span (60%, 73% and 40% respectively)). 32 One study described a single case of surgical removal of medial temporal lobe structures, and another described three cases of bilateral hippocampal atrophy after anoxic brain injury; none of these four individuals failed the WMT.…”

Validating Multi-Dimensional Outcome Assessment Using the Traumatic Brain Injury Common Data Elements: An Analysis of the TRACK-TBI Pilot Study Sample

“…WAIS-IV PSI aggregates the age-adjusted scores on the Symbol Search and Coding subtests 58 and is scaled with a M = 100 and SD = 15. The cut score used in the current project was £ 79, 69 which is just below the ninth percentile.…”