Brenner Colleen A, Rumak Samuel P, Burns Amy M N, Kieffaber Paul D
University of British Columbia, Department of Psychology 2136 West Mall, Vancouver, British Columbia V6T 1Z4, Canada.
College of William & Mary, Department of Psychology, P.O. Box 8795, Williamsburg, VA 23187-8795, USA.
Int J Psychophysiol. 2014 Sep;93(3):398-410. doi: 10.1016/j.ijpsycho.2014.06.006. Epub 2014 Jun 17.
Facial expressions are encoded via sensory mechanisms, but meaning extraction and salience of these expressions involve cognitive functions. We investigated the time course of sensory encoding and subsequent maintenance in memory via EEG. Twenty-nine healthy participants completed a facial emotion delayed match-to-sample task. P100, N170 and N250 ERPs were measured in response to the first stimulus, and evoked theta power (4-7Hz) was measured during the delay interval. Negative facial expressions produced larger N170 amplitudes and greater theta power early in the delay. N170 amplitude correlated with theta power, however larger N170 amplitude coupled with greater theta power only predicted behavioural performance for one emotion condition (very happy) out of six tested (see Supplemental Data). These findings indicate that the N170 ERP may be sensitive to emotional facial expressions when task demands require encoding and retention of this information. Furthermore, sustained theta activity may represent continued attentional processing that supports short-term memory, especially of negative facial stimuli. Further study is needed to investigate the potential influence of these measures, and their interaction, on behavioural performance.
面部表情通过感觉机制进行编码，但这些表情的意义提取和显著性涉及认知功能。我们通过脑电图研究了感觉编码的时间进程以及随后在记忆中的维持情况。29名健康参与者完成了一项面部情绪延迟匹配样本任务。在对第一个刺激做出反应时测量了P100、N170和N250事件相关电位，并在延迟间隔期间测量了诱发的θ波功率（4-7Hz）。负面面部表情在延迟早期产生了更大的N170振幅和更大的θ波功率。N170振幅与θ波功率相关，然而，更大的N170振幅加上更大的θ波功率仅预测了六种测试情绪条件（非常高兴）中的一种情绪条件下的行为表现（见补充数据）。这些发现表明，当任务要求对这些信息进行编码和保留时，N170事件相关电位可能对面部情绪表情敏感。此外，持续的θ波活动可能代表支持短期记忆，尤其是负面面部刺激的短期记忆的持续注意力加工。需要进一步研究来调查这些测量及其相互作用对行为表现的潜在影响。
