School of Psychology, UNSW, Sydney, 2052, Australia.
Neurosci Biobehav Rev. 2021 Jun;125:193-207. doi: 10.1016/j.neubiorev.2021.02.021. Epub 2021 Feb 17.
Although significant progress has been made in understanding the behavioral and brain mechanisms for motivational systems, much less is known about competition between motivational states or motivational conflict (e.g., approach - avoidance conflict). Despite being produced under diverse conditions, behavior during motivational competition has two signatures: bistability and metastability. These signatures reveal the operation of positive feedback mechanisms in behavioral selection. Different neuronal architectures can instantiate this selection to achieve bistability and metastability in behavior, but each relies on circuit-level inhibition to achieve rapid and stable selection between competing tendencies. Paraventricular thalamus (PVT) is identified as critical to this circuit level inhibition, resolving motivational competition via its extensive projections to local inhibitory networks in the ventral striatum and extended amygdala, enabling adaptive responding under motivational conflict.
尽管在理解动机系统的行为和大脑机制方面已经取得了重大进展，但对于动机状态之间的竞争或动机冲突（例如，趋近-回避冲突）知之甚少。尽管是在不同的条件下产生的，但动机竞争期间的行为具有两个特征：双稳定性和亚稳定性。这些特征揭示了行为选择中正反馈机制的运作。不同的神经元结构可以实例化这种选择，从而在行为中实现双稳定性和亚稳定性，但每种结构都依赖于电路级抑制来实现竞争趋势之间的快速和稳定选择。室旁丘脑（PVT）被确定为这种电路级抑制的关键，通过其对腹侧纹状体和扩展杏仁核中局部抑制网络的广泛投射来解决动机竞争，从而在动机冲突下实现适应性反应。
