Neural substrates underlying human delay and trace eyeblink conditioning
Neural substrates underlying human delay and trace eyeblink conditioning
复制标题
DOI：
10.1073/pnas.0800374105
复制
发表时间：
2008-06-10
影响因子：
11.1
通讯作者：
Desmond, John E.
中科院分区：
文献类型：
--
作者：
Cheng, Dominic T.;Disterhoft, John F.;Desmond, John E.
经典的条件反射范式，例如踪迹条件反射，其中条件刺激（CS）的偏移和非条件刺激（US）的传递之间经过一段静默期，以及延迟条件反射，其中CS和US同时终止，被广泛用于研究联想学习的神经基础。然而，我们对人类调节背后的神经系统的了解还存在重大差距。例如，来自动物和人类患者研究的证据表明，海马体在微量眨眼条件反射过程中发挥着关键作用，但迄今为止，没有证据表明人类海马体在微量眨眼条件反射过程中处于活跃状态，或者对延迟和微量范例有不同的反应。目前的工作通过使用功能性 MRI 来直接比较人类延迟和微量眨眼条件反射的神经相关性。行为结果表明，人类可以并行学习延迟和痕迹调节。在小脑中测量到了类似的延迟和微量激活，而与延迟条件反射相比，微量调节期间检测到了更大的海马活动。这些发现进一步支持了以下观点：小脑参与延迟和微量眨眼调节，而海马体对于微量眨眼调节至关重要。这些结果还表明，人类和实验动物支持延迟和微量眨眼经典条件反射的神经回路可能在功能上相似。
Classical conditioning paradigms, such as trace conditioning, in which a silent period elapses between the offset of the conditioned stimulus (CS) and the delivery of the unconditioned stimulus (US), and delay conditioning, in which the CS and US coterminate, are widely used to study the neural substrates of associative learning. However, there are significant gaps in our knowledge of the neural systems underlying conditioning in humans. For example, evidence from animal and human patient research suggests that the hippocampus plays a critical role during trace eyeblink conditioning, but there is no evidence to date in humans that the hippocampus is active during trace eyeblink conditioning or is differentially responsive to delay and trace paradigms. The present work provides a direct comparison of the neural correlates of human delay and trace eyeblink conditioning by using functional MRI. Behavioral results showed that humans can learn both delay and trace conditioning in parallel. Comparable delay and trace activation was measured in the cerebellum, whereas greater hippocampal activity was detected during trace compared with delay conditioning. These findings further support the position that the cerebellum is involved in both delay and trace eyeblink conditioning whereas the hippocampus is critical for trace eyeblink conditioning. These results-also suggest that the neural circuitry supporting delay and trace eyeblink classical conditioning in humans and laboratory animals may be functionally similar.