Individual capacity differences predict working memory performance and prefrontal activity following dopamine receptor stimulation
Individual capacity differences predict working memory performance and prefrontal activity following dopamine receptor stimulation
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DOI：
10.3758/cabn.5.2.212
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发表时间：
2005-06-01
影响因子：
2.9
通讯作者：
D'Esposito, M
中科院分区：
文献类型：
--
作者：
Gibbs, SEB;D'Esposito, M
前额叶皮质(PFC)中有丰富的多巴胺受体，这是参与工作记忆的关键区域。这项药理功能磁共振研究测试了多巴胺、PFC功能和工作记忆容量的个体差异之间的关系。受试者在服用多巴胺受体激动剂溴隐亭或安慰剂后，进行了言语延迟再认任务。溴隐亭治疗的行为效果取决于受试者的工作记忆广度，低工作记忆广度受试者的行为益处最大。溴隐亭作用后，PFC活性与任务探测期间的认知效率指标(RT斜率)呈正相关。记忆提取速度较慢的效率较低的受试者PFC活动较大，而效率较高的受试者的活动较少。服用安慰剂后，这些指标没有相关性。这些结果支持多巴胺在言语工作记忆中的作用，并表明多巴胺可能调节从工作记忆内容中提取项目的效率。因此，PFC多巴胺受体浓度的个体差异可能是多巴胺刺激对工作记忆功能的行为影响的基础。
Dopamine receptors are abundant in the prefrontal cortex (PFC), a critical region involved in working memory. This pharmacological fMRI study tested the relationships between dopamine, PFC function, and individual differences in working memory capacity. Subjects performed a verbal delayed-recognition task after taking either the dopamine receptor agonist bromocriptine or a placebo. Behavioral effects of bromocriptine treatment depended on subjects' working memory spans, with the greatest behavioral benefit for lower span subjects. After bromocriptine, PFC activity was positively correlated with a measure of cognitive efficiency (RT slope) during the probe period of the task. Less efficient subjects with slower memory retrieval rates had greater PFC activity, whereas more efficient subjects had less activity. After placebo, these measures were uncorrelated. These results support the role of dopamine in verbal working memory and suggest that dopamine may modulate the efficiency of retrieval of items from the contents of working memory. Individual differences in PFC dopamine receptor concentration may thus underlie the behavioral effects of dopamine stimulation on working memory function.