Department of Child and Adolescent Mental Health,University of Erlangen-Nuremberg,Erlangen,Germany.
Department of Psychosomatic Medicine and Psychotherapy,University of Erlangen-Nuremberg,Erlangen,Germany.
Psychol Med. 2018 Feb;48(3):508-518. doi: 10.1017/S0033291717001994. Epub 2017 Jul 24.
Aberrant reward mechanisms with regard to slim body shapes are discussed in patients with anorexia nervosa (AN). The aim of the present study was to examine of cue reactivity toward body shapes in AN via the late positive potential (LPP), an event-related electroencephalography (EEG) component. By including adolescents and adults, aspects of development and chronification could be studied (2 × 2 design).
Thirty-two female AN patients (19 adolescents and 13 adults) and 37 control participants (16 adolescents and 21 adults) were included. Standardized photographic stimuli showing women's bodies in underwear from five body mass index (BMI) categories (extremely underweight to extremely overweight) were presented. During picture evaluation, EEG activity was recorded (10-20 system). The LPP was measured in two time windows characterized by different topographies (450-700 ms: posterior; 1000-1300 ms: central).
Regarding the posterior component, LPP amplitudes were clearly reduced in adult but not in adolescent patients; for both time windows the LPP showed differential patterns over BMI categories for patients and controls. Regarding the central component, a highly significant linear decrease from extremely underweight to extremely overweight body shapes was revealed in patients and no significant modulation in control participants.
Adolescent and adult patients show increased sustained attention toward extremely underweight bodies. In chronically ill patients, this bias appears to be accompanied by generally reduced automatic attention. The LPP findings provide a differentiated picture of aberrant cue reactivity which could be interpreted as motivated attention toward body shapes in AN.
厌食症（AN）患者的身体形状存在异常的奖励机制。本研究旨在通过事件相关脑电图（EEG）成分晚期正电位（LPP）来检测 AN 患者对身体形状的线索反应性。通过纳入青少年和成年人，可以研究发展和慢性化的各个方面（2×2 设计）。
共纳入 32 名女性 AN 患者（19 名青少年和 13 名成年人）和 37 名对照参与者（16 名青少年和 21 名成年人）。使用五个身体质量指数（BMI）类别（极度消瘦至极度超重）的女性内衣照片标准刺激物来呈现身体。在图片评估期间，记录 EEG 活动（10-20 系统）。测量了两个时间窗口的 LPP，这两个时间窗口的特征是不同的地形图（450-700ms：后部；1000-1300ms：中央）。
关于后部成分，仅在成年患者中，LPP 幅度明显降低；对于两个时间窗口，患者和对照组的 LPP 在 BMI 类别上均显示出不同的模式。对于中央成分，在患者中发现从极度消瘦到极度超重的身体形状呈现出高度显著的线性下降，而在对照参与者中则没有明显的调节。
青少年和成年患者对极度消瘦的身体表现出增加的持续注意力。在慢性疾病患者中，这种偏差似乎伴随着普遍降低的自动注意力。LPP 研究结果提供了对异常线索反应性的不同描述，这可以解释为 AN 中对身体形状的动机注意力。
