Showing papers by "Grant L. Iverson published in 2008"
TL;DR: There was an inverse relationship between intellectual abilities and prevalence of low memory scores, particularly with the age-adjusted WMS-III scores, and understanding the base rates of low scores can reduce the overinterpretation ofLow memory scores and minimize false-positive misclassification.
Abstract: The psychometric criterion of mild cognitive impairment (MCI) generally involves having an unusually low score on memory testing (i.e., −1.5 SDs). However, healthy older adults can obtain low scores, particularly when multiple memory measures are administered. In turn, there is a substantial risk of psychometrically misclassifying MCI in healthy older adults. This study examined the base rates of low memory scores in older adults (55–87 years; n = 550) from the Wechsler Memory Scale–Third Edition (WMS-III; Wechsler, 1997b) standardization sample. The WMS-III consists of four co-normed episodic memory tests (i.e., Logical Memory, Faces, Verbal Paired Associates, and Family Pictures) that yield eight age- and demographically-adjusted standard scores (Auditory Recognition and Working Memory tests not included). When the eight age-adjusted scores were examined simultaneously, 26% of older adults had one or more scores at or below the 5th percentile (i.e., −1.5 SDs). On the eight demographically- adjusted scores, 39% had at least one score at or below the 5th percentile. There was an inverse relationship between intellectual abilities and prevalence of low memory scores, particularly with the age-adjusted WMS-III scores. Understanding the base rates of low scores can reduce the overinterpretation of low memory scores and minimize false-positive misclassification.Drs. Brooks, Iverson, and Feldman have no known, perceived, or actual conflict of interest with this research. Dr. Holdnack is the Senior Research Director with The Psychological Corporation. (JINS, 2008, 14, 463–478.)
144 citations
TL;DR: An evaluation of neuropsychological abilities is necessary to determine the source of the difficulty as well as the areas of neurocognitive strength that can serve as a foundation for compensatory strategies and treatment options.
107 citations
TL;DR: Normative reference values stratified by age groups provide a frame of reference for interpreting BESS performance in civilians and military personnel who sustain traumatic brain injuries and adults with diverse neurological problems.
Abstract: Primary objective: Patients who sustain traumatic brain injuries can experience temporary or permanent deficits in static or dynamic balance. The Balance Error Scoring System (BESS) is a brief, eas...
71 citations
TL;DR: In contrast to the research literature, these results suggest that individuals who were intoxicated at the time of injury performed similarly, and in some cases, better than those who were sober at theTime of injury.
24 citations
TL;DR: Results show that patients with uncomplicated MTBIs could not be reliably differentiated from patients with substance abuse problems on these cognitive measures, of particular concern for clinicians evaluating the neuropsychological effects of MTBI in individuals with a comorbid history of substance abuse.
Abstract: The purpose of this study was to compare 104 patients with acute uncomplicated mild traumatic brain injury (MTBI) to a sample of 104 patients from an inpatient substance abuse program to determine whether these patients could be differentiated by their pattern of relative cognitive strengths and weaknesses. Patients were matched on age, education, and gender. Eight cognitive measures were used that included tests of attention, memory, and processing speed. There were no statistically significant differences between the two groups on any of the cognitive measures. Using a two-step cluster analysis procedure (i.e., hierarchical and k-means analyses), seven common profiles were identified. There was no significant difference in the proportions of patients from the MTBI or substance abuse group in each of the seven profiles. These results show that patients with uncomplicated MTBIs could not be reliably differentiated from patients with substance abuse problems on these cognitive measures. This is of particul...
18 citations
TL;DR: Investigation of judges' perceptions of credibility in litigated cases involving FM claims in the Canadian courts revealed that judges appear to perceive experts as more credible overall than plaintiffs, regardless of the expert's role in the case.
16 citations
01 Jan 2008
TL;DR: The most common causes of cognitive impairment following motor vehicle collisions are traumatic brain injury, depression, posttraumatic stress disorder, chronic pain, and chronic sleep disturbance, according to as mentioned in this paper.
Abstract: Publisher Summary This chapter describes the myriad of factors that influence an individual's report of neurocognitive impairment, provides information related to definitions and categories of cognitive impairment, and reviews assessment procedures used in diagnosing cognitive disorders. Motor vehicle collisions (MVC) involvement may result in a variety of distress reactions, the type and intensity of these distress reactions determined by parameters of the collision; the number and severity of physical injuries and impairments; the level of pain that accompanies injuries; and the level of compromise to various lifestyle domains and overall quality of life. Cognitive impairment can be transient, temporary, fulminating, or permanent. Some people involved in MVC can have long-term neurological, psychiatric, physical, or psychological problems. These problems, singly or in combination, can have an adverse impact on thinking skills. The complexity lies in accurately identifying problems with cognition, quantifying the deficits, estimating the impact on day-to-day functioning, and apportioning causation. All of these factors, singly or in combination, can have an adverse impact on cognition. Following an MVC, the most common causes of cognitive impairment are traumatic brain injury, depression, posttraumatic stress disorder, chronic pain, and chronic sleep disturbance.
9 citations
TL;DR: This paper evaluated the concurrent validity of estimated Wechsler Adult Intelligence Scales-Third Edition (WAIS-III) index scores using various one-and two-subtest combinations, using all possible one and two subtest combinations to generate an estimated Verbal Comprehension Index, an estimated Perceptual Organization Index (POI), and an estimated Working Memory Index (WMI).
Abstract: This study evaluated the concurrent validity of estimated Wechsler Adult Intelligence Scales—Third Edition (WAIS-III) index scores using various one- and two-subtest combinations. Participants were the Canadian WAIS-III standardization sample. Using all possible one- and two-subtest combinations, an estimated Verbal Comprehension Index (VCI), an estimated Perceptual Organization Index (POI), and an estimated Working Memory Index (WMI) were generated by prorating relevant subtest scores. As expected, two-subtest short forms were consistently more accurate than one-subtest short forms. Agreement between short-form and full-form index scores was high for two-subtest combinations (range = 88% to 96%) but only moderate with one subtest (range = 62% to 79%). Accuracy did not vary by age, ethnicity, gender, or education. However, accuracy was lowest for index scores in the high average to very superior range. These results suggest that although some two-subtest short forms are useful for estimating VCI, POI, and...
6 citations
01 Jan 2008
3 citations
01 Jan 2008
TL;DR: Iverson et al. as discussed by the authors used the CNS Vital Signs battery used in this study to evaluate the effectiveness of the treatment of depression in a clinical trial with a set of patients.
Abstract: Author Notes: The authors thank Drs. C. Thomas Gualtieri and Lynda G. Johnson for providing all the data used in this study. Drs. Gualtieri and Johnson are the two developers of the CNS Vital Signs battery used in this study. Please address correspondence to Grant Iverson, Ph.D., Department of Psychiatry, University of British Columbia, 2255 Wesbrook Mall, Vancouver, B.C., Canada V6T 2A1. Phone: (604) 822-7588; Fax: (604) 822-7756; Email: giverson@interchange.ubc.ca.