Babiloni Claudio, Del Percio Claudio, Valenzano Anna, Marzano Nicola, De Rosas Mario, Petito Annamaria, Bellomo Antonello, Rossi Giuseppe, Lecce Brunello, Mundi Ciro, Lizio Roberta, Eusebi Fabrizio, Cibelli Giuseppe
Department of Biomedical Sciences, Bioagromed, University of Foggia, Foggia, Italy.
Clin Neurophysiol. 2009 Aug;120(8):1441-8. doi: 10.1016/j.clinph.2009.06.012. Epub 2009 Jul 18.
Are obese subjects characterized by a reduction of attentional cortical responses to the enlargement of food or body images?
Electroencephalographic data were recorded in 19 obese and 15 normal-weight adults during an "oddball" paradigm. The subjects were given frequent (70%) and rare (30%) stimuli depicting faces (FACE), food (FOOD), and landscapes (CONTROL), and clicked the mouse after the rare stimuli. These stimuli depicted the same frequent stimuli graphically dilated by 25% along the horizontal axis. Bioelectrical impedance indexed subjects' body fat percentage. Cortical attentional responses were probed by the difference between positive event-related potentials peaking around 400-500ms post-stimulus for the rare minus frequent stimuli (P300). Low resolution electromagnetic source tomography (LORETA) estimated P300 sources.
In the FOOD condition, the amplitude of medial prefrontal P300 sources (Brodmann area 9) was lower in the obese than normal-weight subjects, and there was a negative correlation between the body fat percentage and the amplitude of these sources in all subjects as a single group.
These results disclose that prefrontal attentional processes to food size are abnormal in obese subjects.
The present study motivates future research evaluating the effects of cognitive rehabilitation in obese subjects.
肥胖个体是否具有对食物或身体图像放大的注意力皮层反应降低的特征？
在一个“oddball”范式中，对19名肥胖成年人和15名正常体重成年人记录脑电图数据。给受试者呈现频繁（70%）和罕见（30%）的刺激，包括面部（FACE）、食物（FOOD）和风景（CONTROL），并要求他们在罕见刺激出现后点击鼠标。这些刺激描绘的是相同的频繁刺激在水平轴上图形放大25%后的图像。生物电阻抗测量受试者的体脂百分比。通过刺激后400 - 500毫秒左右出现的罕见刺激减去频繁刺激的正性事件相关电位（P300）之间的差异来探测皮层注意力反应。低分辨率电磁源断层扫描（LORETA）估计P300源。
在食物条件下，肥胖受试者内侧前额叶P300源（布罗德曼区9）的波幅低于正常体重受试者，并且作为一个整体组，所有受试者的体脂百分比与这些源的波幅之间存在负相关。
这些结果表明肥胖受试者对食物大小的前额叶注意力过程异常。
本研究促使未来开展评估认知康复对肥胖受试者影响的研究。
