Department of Physiology and Pharmacology.
PhD program in Behavioral Neuroscience, Sapienza University of Rome, 00185 Rome, Italy, and.
J Neurosci. 2020 Apr 8;40(15):3025-3034. doi: 10.1523/JNEUROSCI.1969-19.2020. Epub 2020 Feb 25.
We can adapt flexibly to environment changes and search for the most appropriate rule to a context. The orbital prefrontal cortex (PFo) has been associated with decision making, rule generation and maintenance, and more generally has been considered important for behavioral flexibility. To better understand the neural mechanisms underlying the flexible behavior, we studied the ability to generate a switching signal in monkey PFo when a strategy is changed. In the strategy task, we used a visual cue to instruct two male rhesus monkeys either to repeat their most recent choice (i.e., stay strategy) or to change it (i.e., shift strategy). To identify the strategy switching-related signal, we compared nonswitch and switch trials, which cued the same or a different strategy from the previous trial, respectively. We found that the switching-related signal emerged during the cue presentation and it was combined with the strategy signal in a subpopulation of cells. Moreover, the error analysis showed that the activity of the switch-related cells reflected whether the monkeys erroneously switched or not the strategy, rather than what was required for that trial. The function of the switching signal could be to prompt the use of different strategies when older strategies are no longer appropriate, conferring the ability to adapt flexibly to environmental changes. In our task, the switching signal might contribute to the implementation of the strategy cued, overcoming potential interference effects from the strategy previously cued. Our results support the idea that ascribes to PFo an important role for behavioral flexibility. We can flexibly adapt our behavior to a changing environment. One of the prefrontal areas traditionally associated with the ability to adapt to new contingencies is the orbital prefrontal cortex (PFo). We analyzed the switching related activity using a strategy task in which two rhesus monkeys were instructed by a visual cue either to repeat or change their most recent choice, respectively using a stay or a shift strategy. We found that PFo neurons were modulated by the strategy switching signal, pointing to the importance of PFo in behavioral flexibility by generating control over the switching of strategies.
我们可以灵活适应环境变化，并寻找最适合上下文的规则。眶额前皮质 (PFo) 与决策、规则生成和维持有关，更普遍地被认为对行为灵活性很重要。为了更好地理解灵活行为的神经机制，我们研究了猴子 PFo 在改变策略时生成切换信号的能力。在策略任务中，我们使用视觉提示指示两只雄性猕猴要么重复他们最近的选择（即保持策略），要么改变它（即转换策略）。为了识别与策略转换相关的信号，我们比较了提示相同或不同策略的非转换和转换试验，分别提示前一次试验。我们发现，转换相关信号在提示呈现期间出现，并且它与策略信号在细胞的亚群中结合。此外，错误分析表明，与转换相关的细胞的活动反映了猴子是否错误地转换了策略，而不是该试验所需的策略。转换信号的功能可能是在旧策略不再适用时提示使用不同的策略，从而赋予灵活适应环境变化的能力。在我们的任务中，转换信号可能有助于实施提示的策略，克服先前提示策略的潜在干扰效应。我们的结果支持了 PFo 对行为灵活性具有重要作用的观点。我们可以灵活地适应不断变化的环境。传统上与适应新环境相关的前额区域之一是眶额前皮质 (PFo)。我们使用策略任务分析了与转换相关的活动，在该任务中，两只猕猴通过视觉提示指示他们分别使用保持或转换策略重复或改变最近的选择。我们发现 PFo 神经元受到策略转换信号的调制，通过生成对策略转换的控制，指出 PFo 在行为灵活性中的重要性。
