Levin E D, Bowman R E
Department of Psychology, University of California, Los Angeles 90024.
Neurotoxicol Teratol. 1988 Nov-Dec;10(6):505-10. doi: 10.1016/0892-0362(88)90085-2.
Two cohorts of monkeys chronically exposed to lead during the first year after birth and their controls were tested during adulthood for choice accuracy on a learning and memory task, delayed spatial alternation (DSA). Neither cohort showed significant lead-related deficits, as had been seen in a previous experiment with monkeys exposed to similar chronic levels of lead during the first year with an additional high pulse given five-six weeks after birth (18,19). On the contrary, the lead-exposed monkeys in the present experiment actually performed slightly better than controls. In the previous (pulse-chronic) study, the deficit occurred at short intertrial delays, suggesting an attentional rather than mnenomic deficit. A lead-induced decrease in attentiveness could also explain the present results. The lower level lead intoxication may have decreased attentiveness to a lesser degree, so that the monkeys were less susceptible to irrelevant stimuli and performed better.
两组在出生后第一年长期接触铅的猴子及其对照组，在成年期接受了一项学习和记忆任务——延迟空间交替（DSA）的选择准确性测试。与之前一项实验不同，在之前的实验中，猴子在出生后第一年接触类似慢性水平的铅，并在出生五到六周后额外给予一次高剂量脉冲，结果显示有明显的与铅相关的缺陷，而此次实验中两组猴子均未表现出显著的与铅相关的缺陷。相反，本实验中接触铅的猴子实际表现比对照组略好。在之前（脉冲 - 慢性）的研究中，缺陷出现在较短的试验间隔延迟时，这表明是注意力缺陷而非记忆缺陷。铅导致的注意力下降也可以解释目前的结果。较低水平的铅中毒可能在较小程度上降低了注意力，因此猴子对无关刺激的敏感度较低，表现更好。
