Comparison of the Wisconsin Card Sorting Test and the Halstead Category Test

Neurocognitive deficits in cocaine users: a quantitative review of the evidence

Studies on the neurocognitive effects of cocaine abuse are equivocal with respect to the specific types of deficits observed, although the vast majority of studies indicate that at least some deficits in certain broad functions such as attention, learning and memory, executive functions, and response speed exist. All of these studies based their results on null hypothesis statistical significance testing (NHSST). It is argued that effect size analysis, which provides information about the magnitude of difference, offers a more valid index of cognitive impairments in a population when compared to NHSST. Accordingly, the objective of the current study was to conduct an effect size analysis (or a meta-analysis in cases where the same test measure was utilized in more than one study) to determine the type and the magnitude of the specific cognitive deficits found as a result of cocaine use. Effect sizes were calculated for each test variable across 15 empirical studies that met inclusion criteria. The results from 481 cocaine users and 586 healthy normal controls revealed that cocaine use had the largest effect on several measures of attention (0.40 < d < 1.10). Moderate to large effect sizes (d > 0.50) were also obtained on tests of visual memory and working memory. Minimal effect sizes (d < 0.30) were obtained on tests of verbal fluency and other language functions and sensory-perceptual functions. Tests of executive functioning produced mixed findings and were interpreted in terms of degree rather than nature of impairment. The results are consistent with findings from neuroimaging and neurochemical studies that have found cocaine use to be associated with dysfunctions in the anterior cingulate gyrus and orbitofrontal cortex; these regions are highly implicated in the mediation of attentional and executive functions, respectively. Methodological limitations of the empirical studies included in the analysis are discussed.

Searching for the meaning of the Category Test and the Wisconsin Card Sort Test: a comparative analysis

The Category Test (CT) and the Wisconsin Card Sort Test (WCST) have long been the major instruments used for the assessment of "frontal lobe" brain damage. These tests have often been used interchangeably by clinicians. However, research to date has disagreed on the extent to which these tests can be interpreted in a similar manner. The current paper examined the interrelationships between the tests in 112 mixed brain injured clients. The results showed relatively small correlations between the tests in the range of .4 to .6 which were eliminated when age, education, premorbid IQ (Vocabulary) and spatial skills (Block Design) were used as covariates. Regression analyses showed clear differences in which WAIS-R tests predicted each test, while factor analysis revealed little overlap between the tests except for a small relationship between the number of WCST categories completed and CT errors. The CT appeared to reflect spatial and spatial analysis skills while the WCST reflected verbal analysis and sequential skills. The results clearly indicate that the tests are not interchangeable and do not reflect the same underlying cognitive skills nor can they be interpreted in the same manner for neuropsychological purposes.

Inhibitory function in nonretarded children with autism

This study examined inhibitory function in nonretarded children with autism (n = 13) and normally developing controls (n = 13) matched on age and IQ. Tasks measuring motor and cognitive components of inhibition were administered to both groups. On the Stop-Signal paradigm, children with autism were able to inhibit motor responses to neutral and prepotent stimuli as well as control subjects. On the Negative Priming task, the groups were equally capable of inhibiting processing of irrelevant distractor stimuli in a visual display. Results suggest that at least two components of inhibition are spared in individuals with autism, standing in contrast to flexibility and other executive deficits that have been found in previous studies. These findings may help distinguish children with autism from those with other neurodevelopmental conditions that involve executive dysfunction.

Effects of crack cocaine on neurocognitive function

Because crack cocaine appears to have a preferential effect on the metabolic and electrophysiological activity of the frontal and temporal regions of the brain (Pascual-Leone et al., 1991a, 1991b; Volkow, 1992), we hypothesized that cognitive measures of those regions would be impaired in crack cocaine users relative to measures in normal volunteers. We used logistic regression to determine the relationship of cocaine usage to neuropsychological test performance. We compared 38 patients with an average of 3.6 (SD = 2.5) years of crack cocaine use and 24.5 (SD = 28.1) days of abstinence to 54 normal volunteers on a battery of neuropsychological tests. Statistical adjustments were made for the effects of age, education, socioeconomic class, and level of depression. Our findings were mixed with regard to purported measures of executive/frontal functioning, with worse performance associated with cocaine usage on the Booklet Categories Test, but better performance associated on others (number of categories on the Wisconsin Card Sorting Test, Controlled Oral Word Association). Cocaine usage was associated with impairment on measures of spatial, but not verbal memory, confrontation naming, and Trail-making Test, Part B, a measure of perceptual-motor speed and cognitive flexibility. In summary, it appears that continuous crack cocaine use produces a dissociative pattern in neuropsychological test performance with improvement on some measures, but deterioration on others. The permanence of these effects remains to be determined with longitudinal studies.

Executive functions and developmental psychopathology

In this paper, we consider the domain of executive functions (EFs) and their possible role in developmental psychopathologies. We first consider general theoretical and measurement issues involved in studying EFs and then review studies of EFs in four developmental psychopathologies: attention deficit hyperactivity disorder (ADHD), conduct disorder (CD), autism, and Tourette syndrome (TS). Our review reveals that EF deficits are consistently found in both ADHD and autism but not in CD (without ADHD) or in TS. Moreover, both the severity and profile of EF deficits appears to differ across ADHD and autism. Molar EF deficits are more severe in the latter than the former. In the few studies of more specific EF tasks, there are impairments in motor inhibition in ADHD but not in autism, whereas there are impairments in verbal working memory in autism but not ADHD. We close with a discussion of implications for future research.

Differential aspects of conceptual processing in the Category Test and Wisconsin Card Sorting Test

Ninety-six veterans from neuropsychiatric wards were administered the Category Test (CT), Wisconsin Card Sorting Test (WCST), and a series of concept formation tests assessing attribute identification and rule learning. The CT and WCST shared only 30% common variance, and related to different facets of concept formation. The WCST was associated with attribute identification, which entails discrimination of relevant features, while the CT was more related to rule learning, which assesses the deduction of classification rules. The CT and WCST should not be regarded as similar measures of one construct such as "abstraction." Use of discrete scores from each test can help assess different aspects of concept formation.

Cognitive deficits among functionally psychotic patients: a rehabilitative perspective

Psychological and neuropsychological assessments of psychiatric patients are usually designed to contribute to or document psychiatric diagnoses. The present article suggests that reframing the task to focus on cognitive rehabilitation issues can contribute significantly to the treatment of the chronic patient. A test protocol is proposed and exemplary tests suggested.