非配對誘發負電位或非配對誘發磁場是一種大腦電生理訊號，在規律的背景環境中出現罕見的刺激便會誘發此神經活動。由於不須專注力或個體行為的高度配合，非配對誘發電生理訊號被廣泛應用來評估聽覺（或視覺、軀體感覺）之感覺記憶完整性以及對於外界環境改變偵測之能力。過去腦造影研究歸納出此訊號主要源自於大腦的聽覺皮質（尤其是上顳迴∕上顳溝）—負責感覺記憶的維持，及額葉皮質區（尤其是下額迴）—負責非自主性注意力轉移。本文將詳細介紹非配對誘發電生理訊號之神經生理功能運作，以及在老化、神經科、精神科及發展障礙疾患之研究發現。在臨床應用層面上，此電生理訊號具有潛力可作為認知腦造影指標，用以評估腦傷疾病嚴重程度、預後追蹤及接受復健介入後之復原情形。

Mismatch negativity (MMN) or its magnetic counterpart (MMNm) is a cerebral response to any discriminable change among repetitive stimulation, and is generated in the absence of attention and behavioral tasks. It has been a useful electrophysiological marker to evaluate the integrity of auditory (somatosensory and visual) sensory memory and automatic change detection. Over the past decades, it has been proposed that the mismatch responses are generated by temporal (particularly superior temporal gyri/sulci) and frontal cortices (particularly inferior frontal gyri). The temporal MMN/MMNm is associated with the formation of auditory sensory memory, while the functional significance of frontal MMN/MMNm reflects the involuntary switching of attention to sound changes. This review will demonstrate how MMN/MMNm could be an index of cognitive decline in the neurological, neuropsychiatric, neurodevelopmental diseases and in normal aging. Furthermore, the strength of MMN/MMNm in terms of assessing illness severity, disease progression and functional recovery after receiving rehabilitation in patients with brain injury will be discussed.