Retrospective and prospective information coding by different neurons in the prefrontal cortex.
Retrospective and prospective information coding by different neurons in the prefrontal cortex.
复制标题
前额皮质不同神经元的回顾性和前瞻性信息编码。
DOI：
10.1097/wnr.0b013e32835c8d66
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
Matsushima A and Tanaka M
中科院分区：
文献类型：
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作者：
Youngwoo Kim;Hiroki Murao;Haruhiko Akiyama.;et al.;Matsushima A and Tanaka M
在维持视觉记忆的过程中，外侧前额叶皮层的神经元表现出持续的活动。先前的研究也表明，前额叶神经元在预期即将到来的视觉刺激时表现出预测活动。由于这些视觉刺激的回顾性和前瞻性编码已经在单独的实验中进行了研究，因此这些过程如何在单个神经元中相互作用仍然是未知的。为了验证这一点，我们记录了单个前额叶神经元，而猴子执行两个行为任务。在一项任务中，动物在固定过程中被动地观看移动物体，而在另一项任务中，它们记住了随后扫视的简要视觉提示的位置。我们发现，许多神经元是反应性的，只有在视觉刺激出现在它们的感受野之后才有反应，而有些神经元是预测性的，甚至在运动刺激进入感受野之前就增加了它们的活性。在记忆引导的扫视实验中，反应神经元在延迟期表现出持续的活动，而预测神经元则没有。对移动刺激的视觉反应延迟与对静止刺激的视觉潜伏期无关。相反，它与记忆引导扫视任务中延迟期间持续活动的幅度相关。我们的数据表明，视觉信息的回顾性和前瞻性编码由不同的神经元群体表示，并且它们的时间偏好在不同的任务条件下是稳定的。反应性信号可能反映短期记忆中的时间整合量，而预测性信号可能仅代表未来事件，与过去信息的维持无关。
Neurons in the lateral prefrontal cortex show sustained activity during the maintenance of visual memory. Previous studies have also indicated that prefrontal neurons show predictive activity in anticipation of upcoming visual stimuli. Because these retrospective and prospective coding of visual stimuli have been examined in separate experiments, how these processes interact in individual neurons remains unknown. To examine this, we recorded from single prefrontal neurons while monkeys performed two behavioural tasks. In one task, the animals passively viewed a moving object during fixation, whereas in the other, they remembered the location of a briefly presented visual cue for subsequent saccades. We found that many neurons were reactive and responded only after the visual stimulus appeared in their receptive field, while some neurons were predictive and increased their activity even before the moving stimulus entered the receptive field. In the memory-guided saccade trials, the reactive neurons exhibited sustained activity during the delay period, whereas the predictive neurons did not. Delays of visual response to a moving stimulus did not correlate with visual latency for a stationary stimulus. Instead, it correlated with the magnitude of sustained activity during the delay period in the memory-guided saccade task. Our data show that retrospective and prospective coding of visual information are represented by distinct neuronal populations, and that their temporal preferences are stable across different task conditions. Reactive signals may reflect the amount of temporal integration in short-term memory, whereas predictive signals may solely represent future events in isolation from the maintenance of past information.