Consideration of the several processes involved in sustained attention underscores the need for techniques designed to separate the components. This study_employed two parameters from signal detection theory, perceptual sensitivity [P(A)] and decision criterion cutoff scores [Z(S/M)]> in the analysis of vigilance performance of hyperactive (« = 30), hypoxic (n = 30), and normal (n = 47) children Signal detection analyses of three Continuous Performance Test conditions indicated that, with increasing age, children obtained significantly more hits, fewer false alarms, higher perceptual sensitivity, and responded with greater caution Overall deficits in signal discrimination (perceptual sensitivity level) were obtained for both the hyperactive and the hypoxic groups when compared to normal age mates Whereas the hypoxic group demonstrated additional decrements in sustaining attention (sensitivity decrement over time), the hyperactive children were impaired by lowresponse caution, reflecting difficulty inhibiting impulsive responses Possible differences in hyperactive sample characteristics across studies and time-related recovery factors following hypoxia are discussed

Although the long-term effects of acute anoxia have been studied, the effects of chronic hypoxia on the developing human brain have received little attention. We studied children with a cyanotic congenital heart defect to assess the impact of chronic hypoxia by eight measures: neurologic examination, visual evoked response, EEG, behavioral adjustment, cognitive, perceptual-motor, and attentional functioning, and school performance. On outcome evaluation, these children evidenced diverse neurophysiologic dysfunction. Chronic hypoxia was associated with impaired motor function, inability to sustain attention, and low academic achievement.

A model of risk potential for developmental outcome was created based on cardiac, medical, surgical, and family-stress factors in 31 children with transposition of the great arteries who had undergone reparative open heart surgery utilizing cardiopulmonary bypass during infancy. Impact of these potential risk factors was assessed by 4 current neurologic measures (neurologic anatomic abnormalities, functional impairment, electroencephalograph [EEG], and Pattern Visual Evoked Potential [PVEP]) and 4 psychologic measures (IQ, achievement, perceptual-motor function, and behavior). Results indicated that adverse developmental outcome was significantly associated with the following medical risk variables: failure of palliative surgery to alleviate hypoxia, prolonged hypoxia, growth failure, congestive heart failure, absence of ameliorating shunting heart defects, stroke, and CNS infection; and two psychosocial moderator variables: socioeconomic status and current life stress. Analysis of a "cumulative risk score" indicated significantly higher risk scores in children with abnormal EEGs, PVEPs, and neurologic examinations. The cumulative risk score highly correlated with composite neurologic outcome (r = .62), IQ (r = -.66), achievement (r = -.60), and perceptual-motor function (r = -.48). While overall outcome was favorable for children with TGA who experienced a single risk event, outcome was compromised if multiple risk factors occurred.

A model of risk potential for developmental outcome was created based on cardiac, medical, surgical, and family-stress factors in 31 children with transposition of the great arteries who had undergone reparative open heart surgery utilizing cardiopulmonary bypass during infancy. Impact of these potential risk factors was assessed by 4 current neurologic measures (neurologic anatomic abnormalities, functional impairment, electroencephalograph [EEG], and Pattern Visual Evoked Potential [PVEP]) and 4 psychologic measures (IQ, achievement, perceptual-motor function, and behavior). Results indicated that adverse developmental outcome was significantly associated with the following medical risk variables: failure of palliative surgery to alleviate hypoxia, prolonged hypoxia, growth failure, congestive heart failure, absence of ameliorating shunting heart defects, stroke, and CNS infection; and two psychosocial moderator variables: socioeconomic status and current life stress. Analysis of a "cumulative risk score" indicated significantly higher risk scores in children with abnormal EEGs, PVEPs, and neurologic examinations. The cumulative risk score highly correlated with composite neurologic outcome (r = .62), IQ (r = -.66), achievement (r = -.60), and perceptual-motor function (r = -.48). While overall outcome was favorable for children with TGA who experienced a single risk event, outcome was compromised if multiple risk factors occurred.

Twenty patients with type I Charcot-Marie-Tooth disease received dietary supplementation with the essential fatty acids (EFA), linoleic and gamma-linolenic acids, and vitamin E. A 3-month blinded trial of placebo (paraffin oil and vitamin E, 81.6 IU/d) was followed by 1 year of 3 grams daily of EFA and vitamin E. Serum fatty acid values doubled, but total esterified fatty acid proportions did not change. Arachidonic acid proportions correlated with the amount of prostaglandin-mediated lymphocyte suppression measured at the same times. Improvement demonstrated at the end of the placebo period by neuropsychological tests and neurologic examination was maintained during the 1 year of EFA supplementation. This effect may reflect a membrane stabilization benefit of vitamin E.

Cardiac responses to non‐signal stimuli and to signal stimuli in a vigilance task were examined in children born with congenital heart defects (CHD), and in normal and attention deficit disordered (ADD) subjects. Overall task performance was lower in subjects with heart defects and in the ADD group. Cardiac measures revealed that normal children displayed significantly larger heart rate deceleration to the target stimuli than did either of the clinical groups. Moreover, although no group differences were observed in the cardiac response to non‐signal auditory stimuli, exaggerated heart rate deceleration was observed to vibrotactile stimuli in both the clinical groups. Regression analyses revealed that the magnitude of the cardiac response to somatosensory stimuli was predictive of task performance (both within and between subject groups), with larger responses associated with higher error rates and lower perceptual sensitivity. Results were suggestive of a predictive relationship between somatosensory reactivity and neuropsychological maturation.

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