Pichon Swann, Guex Raphael, Vuilleumier Patrik
Laboratory for Behavioral Neurology and Imaging of Cognition, Department of Neuroscience, Medical School, and Swiss Center for Affective Sciences, University of Geneva, Geneva, Switzerland.
Faculty of Psychology and Educational Sciences, University of Geneva, Geneva, Switzerland.
PLoS One. 2016 Oct 20;11(10):e0164613. doi: 10.1371/journal.pone.0164613. eCollection 2016.
Unconscious processes are often assumed immune from attention influence. Recent behavioral studies suggest however that the processing of subliminal information can be influenced by temporal attention. To examine the neural mechanisms underlying these effects, we used a stringent masking paradigm together with fMRI to investigate how temporal attention modulates the processing of unseen (masked) faces. Participants performed a gender decision task on a visible neutral target face, preceded by a masked prime face that could vary in gender (same or different than target) and emotion expression (neutral or fearful). We manipulated temporal attention by instructing participants to expect targets to appear either early or late during the stimulus sequence. Orienting temporal attention to subliminal primes influenced response priming by masked faces, even when gender was incongruent. In addition, gender-congruent primes facilitated responses regardless of attention while gender-incongruent primes reduced accuracy when attended. Emotion produced no differential effects. At the neural level, incongruent and temporally unexpected primes increased brain response in regions of the fronto-parietal attention network, reflecting greater recruitment of executive control and reorienting processes. Congruent and expected primes produced higher activations in fusiform cortex, presumably reflecting facilitation of perceptual processing. These results indicate that temporal attention can influence subliminal processing of face features, and thus facilitate information integration according to task-relevance regardless of conscious awareness. They also suggest that task-congruent information between prime and target may facilitate response priming even when temporal attention is not selectively oriented to the prime onset time.
无意识过程通常被认为不受注意力影响。然而，最近的行为研究表明，阈下信息的处理会受到时间注意力的影响。为了探究这些效应背后的神经机制，我们使用了严格的掩蔽范式并结合功能磁共振成像来研究时间注意力如何调节不可见（被掩蔽）面孔的处理。参与者对一个可见的中性目标面孔执行性别判断任务，在此之前会呈现一个被掩蔽的启动面孔，其性别（与目标相同或不同）和表情（中性或恐惧）可能会有所变化。我们通过指示参与者预期目标会在刺激序列的早期或晚期出现来操纵时间注意力。将时间注意力导向阈下启动刺激会影响被掩蔽面孔的反应启动，即使性别不一致时也是如此。此外，性别一致的启动刺激无论注意力情况如何都会促进反应，而性别不一致的启动刺激在被注意时会降低准确性。情绪没有产生差异效应。在神经层面，不一致且时间上意外的启动刺激会增加额顶叶注意力网络区域的大脑反应，这反映出执行控制和重新定向过程的更多参与。一致且预期的启动刺激在梭状回皮层产生更高的激活，大概反映了知觉处理的促进作用。这些结果表明，时间注意力可以影响面孔特征的阈下处理，从而促进根据任务相关性进行信息整合，而无需意识觉知。它们还表明，即使时间注意力没有选择性地导向启动刺激的起始时间，启动刺激和目标之间的任务一致信息也可能促进反应启动。
