題目：Using functional magnetic resonance imaging to explore the flashed face distortion effect

講者：龔俊嘉 博士( 國立成功大學 助理教授)

時間：103年11月20日(週四) 15:30-17:20

地點：教育館225會議室

講者簡介：

        龔俊嘉老師畢業於政大心理系，中正心理所，布朗大學認知科學 博士，與普林斯頓大學心理系與神經科學中心作博士後研究。目前為成 功大學心理系助理教授與成大ＭＲＩ中心成員。龔老師的研究領域主要為臉孔與物體辨識、核磁共振造影實驗法、基礎視覺議題等。以心理物理實驗與功能性磁振造影 (fMRI) 為主要的研究工具。近年來，亦逐漸增加與其他領域 (如神經經濟學，神經社會科學) 的合作，以深耕並拓展在南台灣的腦造影研究為目標。

演講摘要：

         The flashed face distortion (FFD) effect was coined by Tangen, Murphy, and Thompson (2011) in their second-place winner of the 2012 Best Illusion of the Year Contest. The FFD arises when people view various eye-aligned faces that are sequentially flashed in the visual periphery, and gradually the faces appear to be deformed and grotesque. In this functional magnetic resonance imaging (fMRI) study, participants were presented with four conditions: (a) one face pair changing only its illumination; (b) two and (c) three alternating face pairs; and (d) nonrepeated face pairs. Participants rated the magnitude of each illusion immediately after each block. Results showed that the receptive region of the early visual cortex (V1–V4), and category-selective areas such as the fusiform face area (FFA) and occipital face area (OFA), responded proportionally to the participants' rated FFD strength. A random-effects voxelwise analysis further revealed positively correlated areas (including the medial and superolateral frontal areas) and negatively correlated areas (including the precuneus, postcentral gyrus, right insula, and bilateral middle frontal gyri) with respect to participants' ratings. Time series correlations among these nine ROIs (four positive and five negative) indicated that most participants showed a clustering of the two separate ROI types. Exploratory factor analysis (EFA) also demonstrated the segregation of the positive and negative ROIs; additionally, two subsystems were identified within the negative ROIs. These results suggest that the FFD is mediated by at least two networks: one that is likely responsible for perception and another that is likely responsible for subjective feelings and engagement.