Biomedical subjects

Charles W Mathias

Publications and source records attributed to Charles W Mathias.

10 recordsLinked to original sources

PubMed2003

Familial transmission of Continuous Performance Test behavior: attentional and impulsive response characteristics.

Continuous Performance Tests (CPTs) provide information on attentional processing and impulsive behavior. The results of previous research that used self-report measures have provided evidence for familial transmission (through genetic and/or environmental influences) of impulsive characteristics. The authors of the present study examined whether the impulsive behavioral parameters that are measured by the CPT also share familial relationships. The researchers asked 26 healthy parent-adolescent pairs to complete the Immediate and Delayed Memory Tasks (IMT/DMT; D. M. Dougherty, 1999; D. M. Dougherty, D. M. Marsh, & C. W. Mathias, 2002), a modified CPT (B. A. Cornblatt, N. J. Risch, G. Faris, D. Friedman, & L. Erlenmeyer-Kimling, 1988; H. E. Rosvold, A. Mirsky, I. Sarason, E. D. Breansome, Jr., & L. H. Beck, 1956), and the Barratt Impulsiveness Scale (BIS; J. H. Patton, M. S. Stanford, & E. S. Barratt, 1995), a self-report measure. The main findings can be summarized as follows: (a) commission errors (but not correct detections) on the IMT and DMT were correlated between parents and their adolescent children, (b) adolescents emitted a higher proportion of commission errors than did their parents, and (c) self-reported impulsivity (i.e., BIS) was correlated with commission errors for parents, but not for adolescents. The findings of this study support the use of an objective behavioral measure of impulsivity to assess familial relationships of impulsivity.

Adolescent↗

PubMed2003

Commission error rates on a continuous performance test are related to deficits measured by the Benton Visual Retention Test.

This study is one in a series investigating the relationship between impulsive behavior on a Continuous Performance Test (i.e., the Immediate and Delayed Memory Task) and other cognitive deficits measured by clinical instruments. Forty-two adolescents were selected for two groups, controls and hospitalized patients with disruptive behavior disorders. Each adolescent completed the Immediate and Delayed Memory Task and the Benton Visual Retention Test. Our main findings were that, even when controlling for IQ, the Immediate and Delayed Memory Task commission errors were associated with adverse Benton performance, but only in the patient group. These results may be explained by a shared association between processes of impulsivity and other deficits of executive control that may interfere with successful performance of the Benton.

Adolescent↗

PubMed2003

Characterizing aggressive behavior.

In the research literature, aggressive behavior has traditionally been classified into two distinct subtypes, impulsive or premeditated. Impulsive aggression is defined as a hair-trigger aggressive response to provocation with loss of behavioral control. Premeditated aggression is defined as a planned or conscious aggressive act, not spontaneous or related to an agitated state. The present study outlines the development of a clinically useful self-report instrument, the Impulsive/Premeditated Aggression Scales (IPAS), designed to characterize aggressive behavior as predominately impulsive or predominately premeditated in nature. The IPAS showed strong reliability and validity. Analysis of the IPASscores demonstrated thepresence of two types of aggressive behavior, impulsive and premeditated, in men referred for anger problems. The aggression of most individuals in the present sample was characterized as predominately impulsive in nature (90%).

Adult↗

PubMed2002

Increased impulsivity in cocaine dependent subjects independent of antisocial personality disorder and aggression.

Several previous studies show a relationship between impulsivity and substance abuse; however, it is unclear whether the increased impulsivity seen in substance dependent groups is specifically related to substance abuse, or if it is due to concomitant antisocial personality disorder (ASPD) or aggression. The issue of whether impulsivity is specifically related to substance abuse is important since it has a bearing on risk factors for development of substance abuse. To determine whether cocaine dependent subjects show increased impulsivity independent of ASPD, the Barratt impulsiveness scale (BIS-11), a delayed reward laboratory measure of impulsivity, and the life history of aggression scale were administered to 49 cocaine dependent subjects and 25 controls. Results showed that cocaine dependent subjects with ASPD were more impulsive and aggressive than controls, but cocaine dependent subjects without ASPD were also more impulsive compared to controls. Controlling for aggression history, cocaine dependent subjects without ASPD continued to have elevated impulsivity as measured by the BIS-11, but not the delayed reward task. This study supports the hypothesis that the increased impulsivity as measured by the BIS-11 in cocaine dependent individuals is not exclusively due to concomitant increases in aggression or ASPD.

Adult↗

PubMed2002

Detecting malingered performance with the Wisconsin card sorting test: a preliminary investigation in traumatic brain injury.

The present study examined the classification accuracy of four potential Wisconsin Card Sorting Test malingering indicators (Bernard and Suhr formulas and two types of Unique responses). Participants were 89 traumatic brain-injury (TBI) patients assigned to malingering and nonmalingering groups on the basis of the Slick, Sherman, and Iversion (1999) criteria. Individual Sensitivities were greater than .33 with acceptable Specificity. Combined Sensitivity for two of the indicators was greater than.60. Overall, this study demonstrated three distinct approaches to the WCST used by probable malingerers. The clinical relevance of these findings and directions for future research are discussed.

Adult↗

PubMed2002

Wisconsin Card Sorting Test in chronic severe traumatic brain injury: factor structure and performance subgroups.

OBJECTIVE: The present study further investigated the factor structure of the WCST in traumatic brain injury and investigated the construct validity and relationships among scores through the use of cluster analysis. DESIGN: Participants were 68 survivors of chronic severe TBI, living at a residential brain injury rehabilitation facility. METHODS AND PROCEDURES: Three sets of WCST scores were submitted to factor analysis; the regression factor scores based on the standard WCST were examined using cluster analysis. RESULTS: Factor analysis of the WCST raw scores replicated the three-factor solution which has been previously reported. When t-scores were analysed, two-to-four-factor solutions could be justified. The cluster analysis identified four groups representing: (1) impaired response maintenance; (2) problem-solving deficits; (3) intact WCST performance; and (4) deficits in set shifting. CONCLUSIONS: The results support previous research indicating that the WCST is sensitive to three distinct cognitive processes: cognitive flexibility, problem-solving, and response maintenance. However, unlike the cognitive processes underlying WCST performance, the WCST scores representing these processes are not independent. The potential clinical relevance of these results is discussed.

Adolescent↗

PubMed2002

Temporal stability of the Wisconsin Card Sorting Test in a chronic traumatic brain injury sample.

The aim of the present study was to investigate the temporal stability of the Wisconsin Card Sorting Test (WCST) in a clinical population with documented brain pathology, stable cognitive deficits, and for whom repeated testing is common: chronic severe traumatic brain injury (TBI). Participants were 34 patients at least 1 year post severe TBI living at a large residential rehabilitation facility. The WCST was administered in standard fashion with both the standard and 64-card versions scored. All derived scores with norms were examined. Results indicated acceptable temporal stability of most scores for both the standard and short WCST, although the stability of the WCST-64 was poorer than for the standard WCST. Three sets of significant change indices are provided for clinical use.

Adult↗

PubMed2002

Detecting malingered neurocognitive dysfunction using the reliable digit span in traumatic brain injury.

This study assessed the effectiveness of Greiffenstein's Reliable Digit Span (RDS) score for the detection of malingered neurocognitive dysfunction. Participants were 54 traumatic brain injury patients referred for neuropsychological evaluation. Twenty-four met the Slick, Sherman, and Iverson criteria for at least probable malingered neurocognitive dysfunction. The control group was composed of 30 patients without external incentive and who thus did not meet the Slick criteria. All patients completed the digit span test as part of either the WAIS-R or WAIS-III. The RDS scores were calculated, and sensitivity, specificity, and predictive power were examined for several cutoffs. Classification accuracy for the RDS was excellent. Issues related to the clinical application of this technique are discussed.

Adult↗

PubMed2002

Reliability estimates for the immediate and delayed memory tasks.

The Immediate and Delayed Memory Tasks are variations of the Continuous Performance Test. While previous research with the tasks has focused on group performance across multiple blocks and sessions, reliability estimates have not been established. We estimated reliability (1) between blocks of a single testing session (N=106), (2) across four sessions within a single testing day (N=20), and (3) across sessions on four consecutive testing days (N=20). Analyses indicated that the primary variable of interest, i.e., commission of errors, showed acceptable reliability within and across testing periods.

Adult↗

PubMed2002

Immediate and delayed memory tasks: a computerized behavioral measure of memory, attention, and impulsivity.

The Immediate and Delayed Memory Task (IMT/DMT), a variant of the Continuous Performance Test (CPT), is a new software package designed to be a flexible research tool for the study of attention, memory, and impulsivity. This package allows researchers to determine the design to be used during a testing session and to manipulate many of the parameters. It features two components: the IMT and the DMT, both of which present sequential 2- to 7-digit stimuli with variable presentation rates and intertrial intervals. Subjects respond to identically matched stimuli presented consecutively, spanning a brief period of time (IMT), or to stimuli spanning a greater period of time (during which intervening stimuli to be ignored appear; DMT). Task complexity can be adjusted to suit applications for both children and adults. Preliminary studies have demonstrated that these laboratory tasks are sensitive to group differences, produce stable baselines of performance, and are sensitive to drug-induced performance decrements.

Attention↗