Laboratory of Psychophysiology, Department of Neurophysiology, Nencki Institute of Experimental Biology, 3 Pasteur St., 02-093, Warsaw, Poland.
Wroclaw Faculty of Psychology, SWPS University of Social Sciences and Humanities, 30b Ostrowskiego St., 53-238, Wroclaw, Poland.
Sci Rep. 2017 Nov 27;7(1):16438. doi: 10.1038/s41598-017-16679-6.
The self-face has a prioritized status in the processing of incoming visual inputs. As the self-face changes over the lifespan, this stimulus seems to be well-suited for investigation of the self across time. Here, steady-state visual evoked potentials (SSVEP, oscillatory responses to periodic stimulation with a frequency that mirrors the frequency of stimulation) were used to investigate this topic. Different types of faces (present self, past self, close-other's, unknown, scrambled) flickered four times per second in two types of stimulation ('identical', with the same image of a given type of face; 'different', with different images of the same type of face). Each of the 10 stimulation sessions lasted 90 seconds and was repeated three times. EEG data were recorded and analyzed in 20 participants. In general, faces evoked higher SSVEP than scrambled faces. The impact of identical and different stimulation was similar for faces and scrambled faces: SSVEP to different stimuli (faces, scrambled faces) was enhanced in comparison to identical ones. Present self-faces evoked higher SSVEP responses than past self-faces in the different stimulation condition only. Thus, our results showed that the physical aspects of the present and past selves are differentiated on the neural level in the absence of an overt behavior.
自我面孔在处理传入的视觉输入时有优先地位。随着个体生命历程中自我面孔的变化，这种刺激似乎非常适合跨时间研究自我。在这里，我们使用稳态视觉诱发电位（SSVEP，对以与刺激频率相同的频率周期性刺激的振荡反应）来研究这个问题。不同类型的面孔（现在的自我、过去的自我、亲近的他人、未知的、打乱的）以每秒四次的速度在两种刺激类型（“相同”，即给定类型的面孔的相同图像；“不同”，即同一类型的面孔的不同图像）中闪烁。每个刺激阶段持续 90 秒，重复三次。在 20 名参与者中记录和分析 EEG 数据。总的来说，面孔比打乱的面孔诱发更高的 SSVEP。相同和不同刺激的影响对于面孔和打乱的面孔是相似的：与相同刺激相比，不同刺激（面孔、打乱的面孔）的 SSVEP 增强。只有在不同刺激条件下，现在的自我面孔比过去的自我面孔诱发更高的 SSVEP 反应。因此，我们的结果表明，在没有明显行为的情况下，现在和过去的自我的物理方面在神经水平上是有区别的。
