Department of Epileptology, University of Bonn, 53105 Bonn, Germany.
Neuron. 2010 Feb 25;65(4):541-9. doi: 10.1016/j.neuron.2010.02.006.
The human brain is adept at anticipating upcoming events, but in a rapidly changing world, it is essential to detect and encode events that violate these expectancies. Unexpected events are more likely to be remembered than predictable events, but the underlying neural mechanisms for these effects remain unclear. We report intracranial EEG recordings from the hippocampus of epilepsy patients, and from the nucleus accumbens of depression patients. We found that unexpected stimuli enhance an early (187 ms) and a late (482 ms) hippocampal potential, and that the late potential is associated with successful memory encoding for these stimuli. Recordings from the nucleus accumbens revealed a late potential (peak at 475 ms), which increases in magnitude during unexpected items, but no subsequent memory effect and no early component. These results are consistent with the hypothesis that activity in a loop involving the hippocampus and the nucleus accumbens promotes encoding of unexpected events.
人类大脑善于预测即将发生的事件，但在瞬息万变的世界中，检测和编码违反这些预期的事件至关重要。出乎意料的事件比可预测的事件更容易被记住，但这些影响的潜在神经机制仍不清楚。我们报告了来自癫痫患者海马体和抑郁患者伏隔核的颅内 EEG 记录。我们发现，意外刺激增强了早期（187 毫秒）和晚期（482 毫秒）海马电位，并且晚期电位与这些刺激的成功记忆编码有关。来自伏隔核的记录显示出一个晚期电位（在 475 毫秒处达到峰值），在意外项目期间其幅度增加，但没有随后的记忆效应，也没有早期成分。这些结果与以下假设一致，即涉及海马体和伏隔核的循环活动促进了意外事件的编码。
