Social reward motivation increases working memory capacity

为了研究视觉工作记忆与奖赏系统之间的动态关系，我们研究了货币激励延迟反应任务中脑电图仪的脑电节律。14名受试者被要求在保持间隔期间保持几个彩色圆盘(3个或6个)。如果答案正确，他们将获得每次审判开始时提供的价值(0、10或50日元)的金钱奖励。行为学结果表明，高奖赏条件下的视觉工作记忆容量显著高于低奖赏和无奖赏条件下的VWM容量。脑电结果表明，额角(6 Hz)和顶叶α(12 Hz)波幅参与了VWM的维持，因为VWM的活动在保留间期增加，并与VWM的容量相关。从高奖赏状态到无奖赏状态，前额β延迟期波幅(24 Hz)与VWM容量的增加显著相关。有趣的是，只有在高奖励条件下，奖励动机的前额β活动和储存VWM的顶叶α活动显著相关。这些发现表明，在高奖赏条件下，额顶系统在β频域和α频域的动态连接可能与VWM容量的增加有关。

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.