Neurochemical control of patch-leaving decisions via modulation of network dynamics

我应该花大量的时间、精力和金钱搬到另一个城市去找一份新工作吗？还是我应该继续做现在的工作？在行为生态学中，这种停留-切换决策通常被称为斑块离开（觅食决策的一个子类），是我们日常生活中经常面临的一个重要决策问题。由于补丁离开的顺序性质，任何决定的后果都将持续到当前的试验之后——在搬到另一个栖息地之后，一个人不能简单地搬回以前的位置而不必再次支付费用。这使得补丁离开与标准的奖励导向选择不同，在标准的奖励导向选择中不存在这种战略顺序组件。对人类觅食的研究是一个相当新的领域，但已经有研究表明，这种决定依赖于神经回路，这与支持简单的奖励导向选择的神经回路不同（尽管重叠）。虽然迄今为止的证据表明，以前扣带皮层（ACC）为中心的大脑区域网络起着至关重要的作用，但人们对留下补丁的决定背后的神经活动的时间动态知之甚少。迄今为止的研究提示，觅食的关键决策变量（DV）可能表现在ACC皮层的θ和γ范围的振荡活动中。同样，一些研究和理论建议表明神经调节系统在相关计算中起着关键作用。目前的项目将测试一些新的假设。使用MEG和并发的EEG-fMRI，将研究如何在一些候选皮质区域（最重要的是ACC）的皮层振荡活动中表示斑块离开的关键DV。此外，神经化学活性将要么用磁共振光谱测量，要么用药理学挑战来操纵。这将阐明神经化学系统如何通过控制神经活动的时间动态来控制补丁离开的决定。如果对神经化学系统的干扰会扰乱振荡表征和相关行为，这些研究也将提供证据，证明这些模式在多大程度上与斑块离开有因果关系。

Should I spend a lot of time, effort and money to move to a different city for a new job? Or should I stay where I am and stick with my current job? This kind of stay-switch decision, in behavioural ecology often termed patch-leaving (a subclass of foraging decisions), is an important decision problem that we often face in everyday life. Because of the sequential nature of patch-leaving, any decision has consequences that last beyond the current trial - after having moved to a different habitat, one cannot simply move back to the previous location without having to pay a cost again. This makes patch-leaving different from standard reward-guided choice, in which this strategic sequential component is not present. Research on human foraging is a rather new field, but it has already been shown that this kind of decision relies on neural circuitry that is distinct from (albeit overlapping) that supporting simple reward-guided choice. While the evidence so far suggests a crucial role for a network of brain regions centred on the anterior cingulate cortex (ACC), little is known about the temporal dynamics of neural activity underlying patch-leaving decisions. The studies conducted so far hint at the possibility that the key decision variable (DV) for foraging may be represented in cortical oscillatory activity in ACC in the theta and gamma range. Likewise, a few studies and theoretical proposal suggest a key role for neuromodulatory systems in the relevant computations. The present project will test a number of novel hypotheses. Using MEG and concurrent EEG-fMRI, it will be investigated how the key DV for patch-leaving is represented in cortical oscillatory activity in a number of candidate cortical regions, most importantly in the ACC. Furthermore, neurochemical activity will either be measured with MR spectroscopy or manipulated with pharmacological challenges. This will elucidate how neurochemical systems govern patch-leaving decisions by controlling the temporal dynamics of neural activity. If interference with neurochemical systems should perturb both oscillatory representations and associated behaviour, these studies would also provide evidence to what extent these patterns are causally relevant for patch-leaving.