Hickey J E, Suess P E, Newlin D B, Spurgeon L, Porges S W
Intramural Research Program, National Institute on Drug Abuse, Baltimore, MD 21224, USA.
Addict Behav. 1995 Jan-Feb;20(1):43-59. doi: 10.1016/0306-4603(94)00044-y.
Attention and learning problems among children exposed to opiates in utero have been previously reported but are difficult to interpret due to imprecise measurement and inadequate control of postnatal factors. In this study, we used a behavior-based measure of attention (continuous-performance tasks) and a physiological index of sustained attention (cardiac vagal tone) to measure more precisely the process of sustained attention. Boys, aged 7 to 12, exposed to opiates in utero, were compared to boys whose mothers began using illicit substances after the child's birth (environmental controls), and boys whose mothers were non-drug users. This three-group design was intended to isolate in utero effects from postnatal environmental influences. Vagal tone, a measure of heart-rate variability sensitive to vagal influences on the heart, was measured pre- and postbaseline and during the three tasks of the Gordon Diagnostic System (Delay, Vigilance, and Distractibility). Vagal tone has been found to be sensitive to changes in environmental demand for sustained attention in infants, school-age children, and adults. Results indicated that when distractors were added to the vigilance task (Distractibility task), opiate-exposed boys failed to suppress vagal tone compared to both control groups. However, both the opiate-exposed boys and the environmental controls made fewer correct responses than non-drug-exposed controls on this task. These results indicate that normal physiological responses to increased attentional demand may be impaired in boys exposed in utero to opiates in this age range. However, the poor Distractibility scores of both the opiate-exposed and environmental controls suggests an important role of environmental influences on attentional performance.
先前已有报道称，子宫内接触阿片类药物的儿童存在注意力和学习问题，但由于测量不精确以及对产后因素控制不足，这些问题难以解释。在本研究中，我们使用基于行为的注意力测量方法（连续执行任务）和持续注意力的生理指标（心脏迷走神经张力）来更精确地测量持续注意力过程。将7至12岁子宫内接触阿片类药物的男孩与母亲在孩子出生后开始使用非法药物的男孩（环境对照组）以及母亲不使用药物的男孩进行比较。这种三组设计旨在将子宫内的影响与产后环境影响区分开来。迷走神经张力是一种对迷走神经对心脏的影响敏感的心率变异性测量指标，在基线前后以及戈登诊断系统的三项任务（延迟、警觉和分心）期间进行测量。已发现迷走神经张力对婴儿、学龄儿童和成人持续注意力的环境需求变化敏感。结果表明，在警觉任务（分心任务）中添加干扰因素时，与两个对照组相比，子宫内接触阿片类药物的男孩无法抑制迷走神经张力。然而，在这项任务中，子宫内接触阿片类药物的男孩和环境对照组的正确反应都比未接触药物的对照组少。这些结果表明，在这个年龄范围内，子宫内接触阿片类药物的男孩对注意力需求增加的正常生理反应可能受损。然而，子宫内接触阿片类药物的男孩和环境对照组的分心分数都很低，这表明环境影响对注意力表现起着重要作用。
