Neurobionics Research Group, Hungarian Academy of Sciences-Pázmány Péter Catholic University, Budapest, Hungary.
J Neurophysiol. 2010 Mar;103(3):1425-30. doi: 10.1152/jn.00868.2009. Epub 2010 Jan 13.
Humans can efficiently store fine-detailed facial emotional information in visual short-term memory for several seconds. However, an unresolved question is whether the same neural mechanisms underlie high-fidelity short-term memory for emotional expressions at different retention intervals. Here we show that retention interval affects the neural processes of short-term memory encoding using a delayed facial emotion discrimination task. The early sensory P100 component of the event-related potentials (ERP) was larger in the 1-s interstimulus interval (ISI) condition than in the 6-s ISI condition, whereas the face-specific N170 component was larger in the longer ISI condition. Furthermore, the memory-related late P3b component of the ERP responses was also modulated by retention interval: it was reduced in the 1-s ISI as compared with the 6-s condition. The present findings cannot be explained based on differences in sensory processing demands or overall task difficulty because there was no difference in the stimulus information and subjects' performance between the two different ISI conditions. These results reveal that encoding processes underlying high-precision short-term memory for facial emotional expressions are modulated depending on whether information has to be stored for one or for several seconds.
人类可以在视觉短期记忆中高效地存储几秒钟的精细面部情绪信息。然而，一个悬而未决的问题是，在不同的保持间隔下，是否存在相同的神经机制来支持情绪表达的高保真短期记忆。在这里，我们使用延迟的面部情绪辨别任务表明，保持间隔会影响短期记忆编码的神经过程。事件相关电位（ERP）的早期感觉 P100 成分在 1 秒刺激间隔（ISI）条件下比在 6 秒 ISI 条件下更大，而在较长的 ISI 条件下，面孔特异性 N170 成分更大。此外，ERP 反应的与记忆相关的晚期 P3b 成分也受到保持间隔的调制：与 6 秒条件相比，在 1 秒 ISI 条件下 P3b 成分减小。这些发现不能用不同的感觉处理需求或整体任务难度来解释，因为在两种不同的 ISI 条件下，刺激信息和被试的表现没有差异。这些结果表明，基于面部情绪表达的高精度短期记忆的编码过程取决于信息是否需要存储一秒或几秒钟。
