老年人和青年人注意网络的研究

Study of attentional networks in older and young people

目的探讨老年化对警觉、定向和执行控制等x注意网络加工的影响。方法运用注意网络测试(ANT)观察30名老年人和30名青年人正常被试的警觉、定向和执行控制等注意网络功能。结果与青年人被试者(执行网络为66.8±32.3ms;警觉网络为55.9±31.2ms;定向网络为46.1±20.6ms)相比,老年人被试者注意的执行控制网络功能效应时间明显延长(124.3±64.9ms,P<0.01)以及警觉网络功能效应时间明显缩短(31.7±36.6ms,P<0.05),显著受损;而定向网络功能无差异。结论脑的老年化改变显著影响注意网络的认知加工,老年化对注意的执行控制和警觉网络的影响,可能与年龄相关的额叶功能退化和神经递质系统的异常有关。

Objective Previous studies suggest that aging has been associated with impairmnt in attention. Posner and Petersen （1990） proposed that the sources of attention form a specific system of anatomical areas, which can be further broken down into three networks. These networks carry out the functions of alerting, orienting, and executive control. Reaction time measures can be used to quantify the processing efficiency within each of these three networks. However, it is not known whether this is a global attentional deficit or relates to a specific attentional network. The study was designed to estimate the influence of aging on the attention networks in Chinese older and younger adults. Methods This study used the attention network test to compare older with young adults on the efficiency of three anatomically defined attentional networks： alerting, orienting, and executive control. Results Older adults showed a highly significant deficit in the executive network and a smaller but significant deficit alerting networks. The data showed that the older group took longer to resolve conflict than the young （z =-3. 992, P 〈 0.01, Mann-Whitney U）. Older participants were significantly worse than the young people in maintaining the alert state tonically and the phasic response to a warning signal （t（58） = 2.77, P 〈 0.05）. The independent sample t test showed that the older group performed significantly slowly than the young group （t（58） = -9.61, P 〈0.01 ）. There was no deficit in the orienting network between the young and the older people. Conclusions Aging leads to deficits of the alerting and executive networks, but is irrelated to the orienting network. The executive attention has been shown in normal subjects to active the anterior cingnlate and lateral prefrontal areas. Age-related deterioration in the prefrontal lobe and the dopaminergic system may explain the age-related changes in executive and alerting attentional networks.