隨著社群媒體日益普及，其對青年族群心理健康之影響已成為重要研究議題。過去研究多指出社群媒體使用與憂鬱、焦慮等負向心理結果具有關聯，並認為社會比較是其中的重要心理機制。然而，既有研究多聚焦於單一社會比較方向或一般性忌妒，較少同時區分向上與向下社會比較，以及良性與惡性忌妒，亦較少整合個體前置心理因素與神經生理反應進行探討。因此，本研究以社會比較理論為基礎，整合情境性自尊、基本心理需求、社會比較傾向、忌妒及負向情緒，並導入腦電圖（Electroencephalography， EEG）作為客觀生理量測工具，以建構社群媒體使用情境下之完整心理歷程模型。本研究共包含三項研究。首先，以偏最小平方法結構方程模型（Partial Least Squares Structural Equation Modeling， PLS-SEM）建立整體心理歷程模型，探討情境性自尊、基本心理需求、向上與向下社會比較傾向、良性與惡性忌妒，以及憂鬱、焦慮與社交焦慮之間的影響關係。其次，透過社群媒體實驗情境設計，將受試者區分為向上比較／良性忌妒、向上比較／惡性忌妒、向下比較／良性忌妒及向下比較／惡性忌妒四組，比較不同社會比較方向與忌妒類型之心理作用機制與負向情緒差異，並進一步比較學生與社會新鮮人之群體差異。最後，導入 EEG 腦波量測，分析受試者於前測、觀看社群媒體刺激及實驗後測三個階段之腦波表現，並比較不同實驗情境、社會比較方向、忌妒類型及身分別群體之腦波變化。 研究結果顯示，整體模型驗證了情境性自尊、基本心理需求、社會比較傾向、忌妒與負向情緒之間的部分影響關係，支持社群媒體使用情境下之心理歷程模型。研究一結果發現，不同社群媒體比較情境下，部分心理變項間之作用關係具有顯著差異，顯示社會比較方向與忌妒類型可能影響個體心理歷程。研究二結果顯示，學生與社會新鮮人在負向情緒及部分心理構面上呈現顯著差異。研究三結果顯示，受試者於觀看社群媒體刺激期間，高頻腦波活動普遍上升，刺激結束後則逐漸下降；腦波變化量分析亦發現，不同社會比較方向與忌妒類型於部分低頻腦波呈現顯著或邊際顯著差異，反映不同社群媒體情境可能伴隨不同的神經生理反應。 整體而言，本研究透過自陳式問卷與 EEG 腦波量測相互驗證，不僅建構社群媒體使用情境下較完整之心理歷程模型，亦補充過去研究較少同時整合社會比較方向、忌妒類型、青年身分別及神經生理反應之不足。研究結果可作為社群媒體心理健康研究、青年心理健康促進、心理諮商實務及社群媒體平台數位福祉設計之參考依據。;With the widespread use of social media， its impact on the mental health of young adults has become an important research issue. Previous studies have suggested that social media use is associated with negative psychological outcomes， such as depression and anxiety， and have identified social comparison as one of the primary psychological mechanisms underlying these relationships. However， existing research has mainly focused on a single direction of social comparison or general envy， with limited attention to distinguishing both upward and downward social comparison as well as benign and malicious envy. Furthermore， few studies have integrated antecedent psychological factors with neurophysiological responses. Therefore， based on Social Comparison Theory， this study developed a comprehensive psychological process model by integrating state self-esteem， basic psychological needs， social comparison tendencies， envy， and negative emotions. Electroencephalography (EEG) was further incorporated as an objective physiological measurement to examine neurophysiological responses under social media use scenarios. This study consisted of three sub-studies. First， Partial Least Squares Structural Equation Modeling (PLS-SEM) was employed to establish an overall psychological process model examining the relationships among state self-esteem， basic psychological needs， upward and downward social comparison tendencies， benign and malicious envy， and negative emotions， including depression， anxiety， and social anxiety. Second， an experimental social media design was conducted in which participants were randomly assigned to one of four groups: upward social comparison/benign envy， upward social comparison/malicious envy， downward social comparison/benign envy， and downward social comparison/malicious envy. Differences in psychological mechanisms and negative emotional responses across social comparison directions and envy types were examined， followed by comparisons between students and early-career employees. Third， EEG was employed to measure participants′ brainwave activity during three experimental stages (pre-test， exposure to social media stimuli， and post-test)， and brainwave responses were compared across experimental conditions， social comparison directions， envy types， and participant groups. The results indicated that the overall model partially supported the proposed relationships among state self-esteem， basic psychological needs， social comparison tendencies， envy， and negative emotions， thereby supporting the proposed psychological process model under social media use scenarios. The findings of Study 1 revealed significant differences in several psychological pathways across different social media comparison conditions， suggesting that the direction of social comparison and the type of envy may influence individuals′ psychological processes. Study 2 demonstrated significant differences between students and early-career employees in negative emotions and several psychological constructs. The EEG findings in Study 3 showed that high-frequency brainwave activity generally increased during exposure to social media stimuli and gradually declined after the stimulation ended. In addition， analyses of EEG change scores revealed significant or marginally significant differences in several low-frequency brainwave bands across different social comparison directions and envy types， indicating that different social media contexts may be associated with distinct neurophysiological responses. Overall， by integrating self-report questionnaires with EEG measurements， this study not only established a more comprehensive psychological process model for social media use but also addressed the research gap regarding the integration of social comparison directions， envy types， youth identity groups， and neurophysiological responses. The findings provide valuable implications for research on social media and mental health， youth mental health promotion， psychological counseling， and the development of digital well-being strategies for social media platforms.
