正常老年人與阿茲海默病及其臨床前期病人對臉部情緒辨認之同年齡效應研究

Abstract

背景：同年齡效應之探討於近年逐漸獲得重視，然而，因方法學上的限制，過去研究同年齡效應是否存在於臉部情緒辨認能力之結果並不一致。除健康年長者，阿茲海默型失智症之病人具臉孔情緒辨認能力之受損，然尚未有研究探討同年齡效應是否存在於病人之臉孔情緒辨識能力。故本研究先解決過去文獻於方法學上之限制，再探討同年齡效應是否存在於健康年長者及阿茲海默型失智症病 人。方法：本研究共納入138位受試者。實驗一納入27位健康老年受試者及31位健康年輕受試者;於實驗二納入27位健康老年受試者及80位記憶抱怨受試者 (分為主觀認知衰退組、記憶型輕度認知障礙組及阿茲海默型失智症組)。每位受試者接受臉孔情緒辨認作業以測得其臉部情緒辨認能力。結果：實驗一，除年輕人組在看年輕臉孔之中性表情，在健康老年人組、健康年輕人組未呈現顯著之同年齡效應。除生氣之情緒辨認，本研究未發現顯著組間差異。不同年紀之臉孔依不同情緒具不同影響結果：在難過、悲傷之情緒辨認上，年輕人臉孔比老年人臉孔好辨認，而在快樂的情緒辨認上相反。實驗二，僅記憶型輕度認知障礙組、阿茲海默型失智症組於難過情緒辨認時呈同年齡效應之傾向，並易將年輕人的難過 情緒誤認為生氣、將老年人的難過情緒誤認為中性。結論：僅在記憶型輕度認知障礙組、阿茲海默型失智症組發現同年齡效應之傾向，反映因病程進展而導致臉部情緒辨認能力之受損。本研究之低強度情緒—難過之臉部情緒辨認作業，可視為偵測早期阿茲海默症之指標。

Background: The own-age effect, which may affect the accuracy of facial emotion recognition (FER), has been investigated over the last decade. However, due to methodologic limitations and differences, the results were inconsistent. Patients with Alzheimer’s disease (AD) have been reported to show deficits in FER even in early phases. Nevertheless, no study has examined the own-age effect in AD patients. The present study, minimizing prior methodologic drawbacks, thus was to examine this issue in normal adults, and patients with subjective cognitive decline (SCD), amnestic mild cognitive impairment (aMCI) and very mild AD. Methods: The total of 138 participants was recruited in the present study. In experiment 1, 27 healthy older adults and 31 healthy young adults were recruited. In experiment 2, 27 healthy control (HC) and 80 patients with memory complaints, among 3 groups, SCD, MCI, and AD, were recruited. The facial emotion recognition function of all participants was evaluated through our Facial Emotion Recognition Task (FER Task) with Taiwanese facial emotion stimuli. Results: In experiment 1, the own-age effect was not observed in the older adults, but was found in younger adults when decoding neutral photos. No group difference in performing the FER Task was found, except for anger. The photo age effect of the FER on distinct emotions was significant. Younger faces are more accurate than older faces to decode difficult emotions in both younger and older adults. In experiment 2, a tendency of the own-age effect occurred in MCI and AD groups, who showed significant deficits when decoding sadness, and tended to mislabel sadness as anger in younger-face photos, neutral in older-face photos. Conclusions: A tendency of the own-age effect occurred only in MCI and AD groups, but not in normal individuals and SCD groups can reflect the FER deficits in the progression of AD. The results displayed that our FER Task, especially for those items of low-intensity emotion (i.e., sadness), can be a sensitive index for early detection of early dementia.