Watanabe Masataka, Hikosaka Kazuo, Sakagami Masamichi, Shirakawa Shu-ichiro
Department of Psychology, Tokyo Metropolitan Institute for Neuroscience, Tokyo, Japan.
Cortex. 2007 Jan;43(1):53-64. doi: 10.1016/s0010-9452(08)70445-3.
Primate prefrontal delay neurons are involved in retaining task-relevant cognitive information in working memory (WM). Recent studies have also revealed primate prefrontal delay neurons that are related to reward/omission-of-reward expectancy. Such reward-related delay activities might constitute "affective WM" (Davidson, 2002). "Affective" and "cognitive" WM are both concerned with representing not what is currently being presented, but rather what was presented previously or might be presented in the future. However, according to the original and widely accepted definition, WM is the "temporary storage and manipulation of information for complex cognitive tasks". Reward/omission-of-reward expectancy-related neuronal activity is neither prerequisite nor essential for accurate task performance; thus, such activity is not considered to comprise the neural substrates of WM. Also, "affective WM" might not be an appropriate usage of the term "WM". We propose that WM- and reward/omission-of-reward expectancy-related neuronal activity are concerned with representing which response should be performed in order to attain a goal (reward) and the goal of the response, respectively. We further suggest that the prefrontal cortex (PFC) plays a crucial role in the integration of cognitive (for example, WM-related) and motivational (for example, reward expectancy-related) operations for goal-directed behaviour. The PFC could then send this integrated information to other brain areas to control the behaviour.
灵长类动物前额叶延迟神经元参与在工作记忆（WM）中保留与任务相关的认知信息。最近的研究还揭示了与奖励/奖励缺失预期相关的灵长类动物前额叶延迟神经元。这种与奖励相关的延迟活动可能构成“情感工作记忆”（戴维森，2002年）。“情感”和“认知”工作记忆都关注表征的不是当前呈现的内容，而是先前呈现的内容或未来可能呈现的内容。然而，根据最初广泛接受的定义，工作记忆是“为复杂认知任务临时存储和处理信息”。与奖励/奖励缺失预期相关的神经元活动对于准确的任务表现既不是先决条件也不是必不可少的；因此，这种活动不被认为构成工作记忆的神经基础。此外，“情感工作记忆”可能不是“工作记忆”一词的恰当用法。我们提出，与工作记忆和奖励/奖励缺失预期相关的神经元活动分别关注表征为了实现一个目标（奖励）应该执行哪种反应以及该反应的目标。我们进一步表明，前额叶皮质（PFC）在整合用于目标导向行为的认知（例如，与工作记忆相关的）和动机（例如，与奖励预期相关的）操作中起着关键作用。然后，前额叶皮质可以将这种整合信息发送到其他脑区以控制行为。
