Social reward motivation increases working memory capacity

为了探讨视觉工作记忆（VWM）与奖励系统之间的动态关系，我们研究了在货币激励延迟反应任务中的脑电图（EEG）节律。14名受试者被要求在保留间隔内保留几个彩色磁盘（3或6）。如果答案正确，他们将在每次试验开始时获得价值（0,10或50日元）的金钱奖励。行为学结果表明，与低奖励和无奖励条件相比，高奖励条件下的VWM能力显著增加。脑电图结果显示，额叶θ (6Hz)和顶叶α (12Hz)振幅参与VWM的维持，因为活动在保持间隔期间增加，并且与VWM容量相关。额叶β延迟期幅值（24Hz）与高奖励条件到无奖励条件下VWM容量的增加显著相关。有趣的是，只有在高奖励条件下，奖励动机的额叶β活动和VWM存储的顶叶α活动才显著相关。这些发现表明，在高奖励条件下，额顶叶系统在β和α频域上的动态联系可能与VWM能力的增加有关。

To investigate the dynamic relationships between the visual working memory (VWM) and reward systems, we focused on the electroencephalograph (EEG) rhythms during a monetary incentive delayed-response task. 14 subjects were required to maintain several colored disks (3 or 6) during the retention interval. In case of the correct answer, they got the monetary reward which value (0, 10 or 50 Japanese yen) was presented at the beginning of each trial. Behavioral results showed that the VWM capacity for the high-reward condition was significantly increased as compared with the low- or no-reward conditions. EEG results showed that the frontal theta (6Hz) and the parietal alpha (12Hz) amplitudes are involved in the maintenance of the VWM since the activities increased during the retention interval and were correlated with the VWM capacity. The frontal beta delay-period amplitudes (24Hz) were significantly correlated with the increases of the VWM capacity from the high-reward to no-reward conditions. Interestingly, the frontal beta activity for reward motivation and the parietal alpha activity for VWM storage were significantly correlated under only the high-reward conditions. These findings suggest that the frontal-parietal system dynamically linked in beta and alpha frequency domains may implicate the increasing VWM capacity under high reward condition.