Saccade-related activity in the prefrontal cortex: its role in eye movement control and cognitive functions.
Saccade-related activity in the prefrontal cortex: its role in eye movement control and cognitive functions.
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DOI：
10.3389/fnint.2014.00054
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发表时间：
2014
影响因子：
3.5
通讯作者：
Funahashi S
中科院分区：
文献类型：
--
作者：
Funahashi S
前额叶神经元表现出与眼跳相关的活动，而与眼跳前记忆相关的活动通常编码即将到来的眼动的方向，这与前额叶对灵活控制自愿眼动的贡献是一致的。然而，许多前额叶神经元表现出跳视后的活动，这种活动是在眼球运动开始之后很久才开始的。虽然在前部眼场观察到了扫视后的活动，但这种活动被认为是眼球运动中心的必然放电，因为这种活动没有显示出方向性调节，而且无论是否有目标，每当猴子进行眼球运动时都会观察到这种活动。然而，前额后扫视活动表现出与前眼跳活动类似的方向性调节，并表现出上下文依赖性，因此只有当猴子进行目标定向眼跳时才能观察到后眼跳活动。前额叶后扫视活动的上下文依赖性表明，这种活动不是来自眼球运动中心的必然信号的结果，而是与前额叶皮质的其他功能有关。其中一个功能可能是在行为反应完成后终止与记忆相关的活动。在前额叶活动的人群分析中，记忆相关活动的终止与眼跳后活动的启动相吻合，这一观察结果支持了这一观点。在试验结束时终止与记忆有关的活动，确保受试者能够准备接收新的和更新的信息。另一个功能可能是监控行为表现，因为眼跳后活动对记忆相关活动的终止可能与告知反应的正确性和试验的终止有关。然而，还需要进一步研究前额叶皮质眼跳相关活动的特点，以及它们在眼动控制和各种认知功能中的功能。
Prefrontal neurons exhibit saccade-related activity and pre-saccadic memory-related activity often encodes the directions of forthcoming eye movements, in line with demonstrated prefrontal contribution to flexible control of voluntary eye movements. However, many prefrontal neurons exhibit post-saccadic activity that is initiated well after the initiation of eye movement. Although post-saccadic activity has been observed in the frontal eye field, this activity is thought to be a corollary discharge from oculomotor centers, because this activity shows no directional tuning and is observed whenever the monkeys perform eye movements regardless of goal-directed or not. However, prefrontal post-saccadic activities exhibit directional tunings similar as pre-saccadic activities and show context dependency, such that post-saccadic activity is observed only when monkeys perform goal-directed saccades. Context-dependency of prefrontal post-saccadic activity suggests that this activity is not a result of corollary signals from oculomotor centers, but contributes to other functions of the prefrontal cortex. One function might be the termination of memory-related activity after a behavioral response is done. This is supported by the observation that the termination of memory-related activity coincides with the initiation of post-saccadic activity in population analyses of prefrontal activities. The termination of memory-related activity at the end of the trial ensures that the subjects can prepare to receive new and updated information. Another function might be the monitoring of behavioral performance, since the termination of memory-related activity by post-saccadic activity could be associated with informing the correctness of the response and the termination of the trial. However, further studies are needed to examine the characteristics of saccade-related activities in the prefrontal cortex and their functions in eye movement control and a variety of cognitive functions.