DataSheet_3_A Neglected Topic in Neuroscience: Replicability of fMRI Results With Specific Reference to ANOREXIA NERVOSA.pdf

Functional magnetic resonance imaging (fMRI) studies report impaired functional correlates of cognition and emotion in mental disorders. The validity of preexisting studies needs to be confirmed through replication studies, which there is a lack of. So far, most replication studies have been conducted on non-patients (NP) and primarily investigated cognitive and motor tasks. To fill this gap, we conducted the first fMRI replication study to investigate brain function using disease-related food stimuli in patients with anorexia nervosa (AN). Using fMRI, we investigated 31 AN patients and 27 NP for increased amygdala and reduced midcingulate activation when viewing food and non-food stimuli, as reported by the original study (11AN, 11NP; Joos et al., 2011). Similar to the previous study, we observed in the within group comparisons (food>non-food) a frontoinsular activation for both groups. Although in AN the recorded activation clustered more prominently and extended into the cingulate cortex. In the between-group comparisons, the increased amygdala and reduced midcingulate activation could not be replicated. Instead, AN showed a higher activation of the cingulate cortices, the pre-/postcentral gyrus and the inferior parietal lobe. Unlike in the initial study, no significant differences between NP>AN could be observed. The inconsistency of results and the non-replication of the study could have several reasons, such as high inter-individual variance of functional correlates of emotion processing, as well as intra-individual variances and the smaller group size of the initial study. These results underline the importance of replication for assessing the reliability and validity of results from fMRI research.

功能磁共振成像（functional magnetic resonance imaging, fMRI）研究显示，精神障碍患者的认知与情感功能关联存在受损情况。现有相关研究的有效性亟需通过重复研究加以验证，但目前此类重复研究仍较为匮乏。截至目前，绝大多数重复研究均以非被试者（non-patients, NP）为对象，且主要围绕认知与运动任务展开。为填补这一研究空白，本团队开展了首项针对神经性厌食症（anorexia nervosa, AN）患者的fMRI重复研究，采用疾病相关食物刺激探究其脑功能变化。

本研究借助fMRI技术，对31名AN患者与27名NP进行扫描，旨在验证初始研究（11名AN患者、11名NP；Joos等，2011）中提出的：观看食物与非食物刺激时，杏仁核（amygdala）激活增强、扣带回中部激活减弱这一结论。与既往研究一致，组内比较（食物>非食物）结果显示，两组受试者均出现额岛叶激活；但AN组的激活簇更为显著，且延伸至扣带回皮层（cingulate cortex）。

组间比较中，本研究未能重复出初始研究中杏仁核激活增强、扣带回中部激活减弱的结果。与之相反，AN组的扣带回皮层、中央前/后回（pre-/postcentral gyrus）以及顶下小叶（inferior parietal lobe）激活程度更高。与初始研究不同的是，本研究未观察到NP组相较于AN组存在显著激活差异。

研究结果不一致且未能实现重复，可能存在多方面原因，例如情感加工功能关联的个体间差异较大，同时存在个体内差异，且初始研究的样本量较小。上述结果凸显了重复研究对于验证fMRI研究结果的可靠性与有效性的重要意义。