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J A Crouch

Publications and source records attributed to J A Crouch.

12 recordsLinked to original sources
PubMed2001

Classification accuracy of the portland digit recognition test in traumatic brain injury.

This study examined the classification accuracy of the Portland Digit Recognition Test (PDRT) in traumatic brain injury (TBI). It differs from past studies in assigning patients to malingering and control groups on the basis of compensation-seeking status and the presence of external markers for malingering. Sensitivity and Specificity were.77 and 1.00, respectively. Past research comparing compensation-seekers to noncompensation-seekers reported Sensitivities of.33 or lower (Specificity is always high). This study demonstrates that past research has seriously underestimated the Sensitivity of the PDRT and raises questions about the true Sensitivity of other malingering techniques as well.

Adult↗
PubMed2001

Impact of childhood rape and aggravated assault on adult mental health.

Associations among childhood assault (rape, aggravated assault, or both) and indices of adult mental health (posttraumatic stress disorder, major depressive episode) were examined in a national probability sample of 4,008 (weighted) women. Relationships among assault characteristics and these adult mental health indices were also investigated. Findings suggested particularly deleterious effects for childhood aggravated assault and rapes that caused additional physical injury.

Adolescent↗
PubMed1997

Factorial structure of the Wisconsin Card Sorting Test.

This study examined the factorial structure of the Wisconsin Card Sorting Test (WCST) in normal university students (N = 135) and a mixed clinical sample (N = 139). Two highly stable orthogonal factors were observed accounting for 70 and 21 per cent of the variance, respectively. Factor I was interpreted as reflecting undifferentiated executive function while Factor II may measure cognitive abilities associated with attentional function. This work can serve as the basis for further examination of the construct validity of the WCST and has implications for its use.

Adult↗
PubMed1996

The California Card Sorting Test may dissociate verbal and non-verbal concept formation abilities.

Most neuropsychological measures of executive function provide only global indices of performance and are relatively insensitive to lateralized dysfunction. The present paper presents a right temporal lobectomy patient whose performance indicates that the California Card Sorting Test, a new measure of executive function, may dissociate verbal and non-verbal concept formation abilities. This case highlights the potential research and clinical value of this test compared to that of existing tests of executive function.

Adult↗
PubMed1995

A psychometric analysis of the California Card Sorting Test.

The purpose of this study is to begin to characterize performance on the California Card Sorting Test (CCST), a relatively new measure of executive function specifically designed to fractionate problem-solving ability into its cognitive components. Data describing the performance of 135 neurologically intact young adults on the CCST and four other common measures of executive function are presented. Factor analyses indicated that the CCST is a valid measure of concept formation and abstract ability and that the CCST taps abilities different from those measured by commonly used tests of executive function. While further work must be done, the CCST seems to hold promise as a neuropsychological assessment instrument.

Journal Article↗
PubMed1977

Humoral immunostimulation. VIII. Increased incorporation of phosphate and turnover of phosphatidylinositol in cells treated with antibody.

Uptake of phosphate (32P) in L cells was modulated by reaction with anti-L cell antibody. A biphasic response was noted with high, cytotoxic concentrations inhibiting 32P uptake and low, cytostimulatory concentrations stimulating 32P uptake. Stimulation of 32P uptake was dependent upon multivalent binding as immune IgG and F(ab')2 were effective, but univalent Fab' was ineffective in enhancing 32P uptake into cells. Antibody stimulation of 32P uptake appeared to be an energy independent process and to take place by activation of 32P membrane transport with an increased Vmax (19.3 pmoles/min to 25.3 pmoles/min), but the same Km (0.22 mM). Isolation and measurement of cellular (primarily membrane) phospholipids demonstrated a dramatic increase of (2-fold) specific radioactivity in phosphatidylinositol. Early turnover of phosphatidylinositol may be an important signal for tumor cells to grow at an enhanced rate when exposed to cytostimulatory concentrations of antibody.

Animals↗
PubMedDate not supplied

Selected cases of poor outcome following a minor brain trauma: comparing neuropsychological and positron emission tomography assessment.

Neuropsychological residua are common particularly in the early stages following a minor traumatic brain injury (TBI), however, a minority of individuals complain of persistent deficits following months or years post-accident. Nine such cases are presented with little or no evidence of brain damage demonstrated according to non-functional neuroimaging (for example CT, MRI), yet their neuropsychological examinations were positive. Since the introduction of positron emission tomography (PET), which captures a functional approach, the question arose as to what extent the two techniques (i.e. PET and neuropsychological examination) are interrelated. All nine minor TBI cases revealed a corroboration between the positive neuropsychological findings confirmed on the PET. The PET procedure documented neuropathology which frequently was pronounced in the frontal and anteriotemporo-frontal regions. Moreover, no significant differences were evident between those five cases with reported loss of consciousness vs. those four cases without.

Adult↗