Abstract：
The systolic and diastolic phases of the cardiac cycle are known to affect perception and cognition differently. Higher order processing tends to be facilitated at systole, whereas sensory processing of external stimuli tends to be impaired at systole compared to diastole. The current study aims to examine whether the cardiac cycle affects auditory deviance detection, as reflected in the mismatch negativity (MMN) of the event-related brain potential (ERP). We recorded the intensity deviance response to deviant tones (70 dB) presented among standard tones (60 or 80 dB, depending on blocks) and calculated the MMN by subtracting standard ERP waveforms from deviant ERP waveforms. We also assessed intensity-dependent N1 and P2 amplitude changes by subtracting ERPs elicited by soft standard tones (60 dB) from ERPs elicited by loud standard tones (80 dB). These subtraction methods were used to eliminate phase-locked cardiac-related electric artifacts that overlap auditory ERPs. The endogenous MMN was expected to be larger at systole, reflecting the facilitation of memory-based auditory deviance detection, whereas the exogenous N1 and P2 would be smaller at systole, reflecting impaired exteroceptive sensory processing. However, after the elimination of cardiac-related artifacts, there were no significant differences between systole and diastole in any ERP components. The intensity-dependent N1 and P2 amplitude changes were not obvious in either cardiac phase, probably because of the short interstimulus intervals. The lack of a cardiac phase effect on MMN amplitude suggests that preattentive auditory processing may not be affected by bodily signals from the heart.
摘要：
已知心动周期的收缩期和舒张期不同地影响感知和认知。高阶处理往往在收缩期得到促进，而与舒张期相比，收缩期外部刺激的感觉处理往往会受损。当前的研究旨在检查心动周期是否会影响听觉偏差检测，如事件相关脑电位（ERP）的失配负性（MMN）所反映。我们记录了对标准音调（60或80dB，取决于块），并通过从偏离的ERP波形中减去标准的ERP波形来计算MMN。我们还通过从响亮的标准音调（80dB）引起的ERP中减去柔和的标准音调（60dB）引起的ERP来评估强度依赖性N1和P2幅度的变化。这些减法方法用于消除与听觉ERP重叠的锁相心脏相关的电伪影。内源性MMN预计在收缩期较大，反映了基于记忆的听觉偏差检测的促进，而外源性N1和P2在收缩期较小，反映受损的外在感觉加工。然而,在消除心脏相关的伪影之后，任何ERP成分的收缩期和舒张期之间均无显著差异.强度依赖性N1和P2振幅变化在任一心脏阶段均不明显，可能是因为刺激间隔很短。缺乏对MMN振幅的心脏相位影响表明，注意力集中的听觉处理可能不会受到来自心脏的身体信号的影响。
