Department of Psychology, General and Experimental Psychology Unit, Ludwig-Maximilians University, D-80802, Munich, Germany.
Sci Rep. 2017 Nov 28;7(1):16525. doi: 10.1038/s41598-017-16595-9.
Interoception refers to the signaling of internal bodily commands. Here, we explore repetition suppression of intero- and exteroceptive neural markers to test whether the perception and predictability of exteroceptive stimulus material affects their expression. Participants completed a repetition suppression paradigm in which angry or neutral facial expressions repeated or alternated. Participants received either an implicit (experiment 1) or explicit (experiment 2) cue enabling the formation of expectations regarding the upcoming facial expression. We measured the heartbeat-evoked potential (HEP) indexing cardiac processing and visual evoked potentials (VEP) in response to viewing the second (repeated or alternated) face. Repeating angry facial expressions produced repetition suppression of both HEP and VEP amplitude while repeating neutral expressions led to repetition enhancement of HEP amplitude. This effect was magnified when participants were explicitly aware of predictive cues. Furthermore, repetition suppression of HEP amplitude correlated with neural attenuation of VEP activity. Results highlight repetition effects for interoceptive as well as exteroceptive neural markers and support top-down, expectation-based accounts of the phenomenon. Furthermore, results demonstrate that the perception of exteroceptive stimulus information has an effect on the processing of interoceptive signals and suggest a direct neural connection between the processing of external and internal sensory information.
内感受是指对内部身体指令的信号传递。在这里，我们探索了内感受和外感受神经标记的重复抑制，以测试对外感受刺激材料的感知和可预测性是否会影响它们的表达。参与者完成了一个重复抑制范式，在该范式中，愤怒或中性的面部表情重复或交替出现。参与者接受了隐含（实验 1）或明确（实验 2）的线索，从而形成了对即将出现的面部表情的预期。我们测量了心跳诱发电位（HEP），以索引心脏处理，以及观看第二张（重复或交替）面孔时的视觉诱发电位（VEP）。重复呈现愤怒的面部表情会导致 HEP 和 VEP 幅度的重复抑制，而重复呈现中性表情会导致 HEP 幅度的重复增强。当参与者明确意识到预测线索时，这种效应会放大。此外，HEP 幅度的重复抑制与 VEP 活动的神经衰减相关。结果突出了内感受和外感受神经标记的重复效应，并支持了基于预期的自上而下的现象解释。此外，结果表明，对外感受刺激信息的感知对外感受信号的处理有影响，并暗示了外部和内部感觉信息处理之间的直接神经联系。
