Laboratory for Sensorimotor Research, National Eye Institute, National Institutes of Health, Bethesda, Maryland 20892
Department of Neurobiology, Harvard Medical School, Howard Hughes Medical Institute, Boston, Massachusetts 02115.
J Neurosci. 2020 May 6;40(19):3751-3767. doi: 10.1523/JNEUROSCI.2587-19.2020. Epub 2020 Apr 9.
Behavior can be guided by neuronal activity in visual, auditory, or somatosensory cerebral cortex, depending on task requirements. In contrast to this flexible access of cortical signals, several observations suggest that behaviors depend more on neurons in later areas of visual cortex than those in earlier areas, although neurons in earlier areas would provide more reliable signals for many tasks. We recorded from neurons in different levels of visual cortex of 2 male rhesus monkeys while the animals did a visual discrimination task and examined trial-to-trial correlations between neuronal and behavioral responses. These correlations became stronger in primary visual cortex as neuronal signals in that area became more reliable relative to the other areas. The results suggest that the mechanisms that read signals from cortex might access any cortical area depending on the relative value of those signals for the task at hand. Information is encoded by the action potentials of neurons in various cortical areas in a hierarchical manner such that increasingly complex stimulus features are encoded in successive stages. The brain must extract information from the response of appropriate neurons to drive optimal behavior. A widely held view of this decoding process is that the brain relies on the output of later cortical areas to make decisions, although neurons in earlier areas can provide more reliable signals. We examined correlations between perceptual decisions and the responses of neurons in different levels of monkey visual cortex. The results suggest that the brain may access signals in any cortical area depending on the relative value of those signals for the task at hand.
行为可以通过视觉、听觉或躯体感觉大脑皮层中的神经元活动来指导，具体取决于任务要求。与皮质信号的这种灵活访问方式形成对比的是，有几个观察结果表明，行为更多地依赖于视觉皮层后期区域的神经元，而不是早期区域的神经元，尽管早期区域的神经元会为许多任务提供更可靠的信号。当两只雄性恒河猴进行视觉辨别任务时，我们记录了它们不同层次的视觉皮层中的神经元，并检查了神经元和行为反应之间的逐次试验相关性。当该区域的神经元信号相对于其他区域变得更可靠时，初级视觉皮层中的这些相关性变得更强。结果表明，读取皮质信号的机制可能会根据手头任务中这些信号的相对价值访问任何皮质区域。信息以分层的方式由各个皮质区域的神经元动作电位进行编码，使得越来越复杂的刺激特征被编码在连续的阶段中。大脑必须从适当神经元的反应中提取信息以驱动最佳行为。对该解码过程的一种广泛观点是，大脑依赖于较晚的皮质区域的输出做出决策，尽管早期区域的神经元可以提供更可靠的信号。我们检查了猴子视觉皮层不同层次的神经元的反应与感知决策之间的相关性。结果表明，大脑可能会根据手头任务中这些信号的相对价值访问任何皮质区域的信号。
