MEG-Center, University of Tübingen, Tübingen, Germany.
Neuroimage. 2010 Oct 1;52(4):1584-91. doi: 10.1016/j.neuroimage.2010.04.278. Epub 2010 May 7.
The importance of food stimuli for all living organisms is defined by their relevance for survival. Therefore, visual processing of food stimuli is influenced by many factors, such as cultural and societal background. In this magnetoencephalography (MEG) study, we examined the categorization and memorization of visual food and non-food stimuli in lean subjects, using a one-back working memory task. We found an increase in neural activity in several different regions of the brain elicited by food stimuli in comparison to non-food stimuli. The first observed significant difference was found in low-level visual areas as early as 120 ms after stimulus onset. The stimulus category of the previous picture did not influence this effect. However, preceding stimuli modulated behavioral measures (reaction time and accuracy of responses) and later components of the evoked responses around 350 ms. The evoked magnetic field of this late component showed a significant increase inactivity in the temporal cortex for food versus non-food objects. This late component exhibited a significant correlation with the reaction time. The difference of category-specific effects in the early components and the behavioral modulation of late components could be useful for further investigations of the cortical activity in response to food stimuli, e.g. in subjects with eating disorders or obesity.
所有生物对食物刺激的重视程度取决于它们对生存的重要性。因此，视觉对食物刺激的处理受到许多因素的影响，如文化和社会背景。在这项磁共振脑磁图（MEG）研究中，我们使用了一种一背工作记忆任务，检查了瘦素受试者对视觉食物和非食物刺激的分类和记忆。与非食物刺激相比，我们发现食物刺激引起了大脑中几个不同区域的神经活动增加。早在刺激开始后 120 毫秒，就观察到了第一个明显的差异，发生在低水平视觉区域。前一张图片的刺激类别并不影响这种效应。然而，前刺激调节了行为测量（反应时间和反应准确性）和诱发反应的稍后组成部分，大约在 350 毫秒。这个晚成分的诱发磁场显示出食物与非食物物体在颞叶皮层的活动显著增加。这个晚成分与反应时间有显著的相关性。早期成分中特定类别的影响差异和晚期成分的行为调节对于进一步研究皮质活动对食物刺激的反应可能是有用的，例如在饮食失调或肥胖的受试者中。
