Research Report Processing of food pictures: Influence of hunger, gender and calorie content Sabine Frank a,b, ⁎ ,1 , Naima Laharnar a,1 , Stephanie Kullmann a,b , Ralf Veit a,b , Carlos Canova a , Yiwen Li Hegner a,b , Andreas Fritsche c , Hubert Preissl a,c,d a MEG-Center, University of Tübingen, Tübingen, Germany b Institute of Medical Psychology and Behavioral Neurobiology, University of Tübingen, Tübingen, Germany c Division of Endocrinology, Diabetology, Angiology, Nephrology, and Clinical Chemistry, Department of Internal Medicine, University Hospital of Tübingen, Tübingen, Germany d Department of Obstetrics and Gynaecology, University of Arkansas for Medical Sciences, Little Rock, USA ARTICLE INFO ABSTRACT Article history: Accepted 14 April 2010 Available online 25 April 2010 In most cases obesity, a major risk factor for diabetes mellitus type 2 and other associated chronic diseases, is generated by excessive eating. For a better understanding of eating behavior, it is necessary to determine how it is modulated by factors such as the calorie content of food, satiety and gender. Twelve healthy normal weighted participants (six female) were investigated in a functional magnetic resonance imaging (fMRI) study. In order to prevent the influence of social acceptability, an implicit one-back task was chosen for stimulus presentation. We presented food (high- and low-caloric) and non-food pictures in a block design and subjects had to indicate by button press whether two consecutive pictures were the same or not. Each subject performed the task in a hungry and satiated state on two different days. High-caloric pictures compared to low-caloric pictures led to increased activity in food processing and reward related areas, like the orbitofrontal and the insular cortex. In addition, we found activation differences in visual areas (occipital lobe), despite the fact that the stimuli were matched for their physical features. Detailed investigation also revealed gender specific effects in the fusiform gyrus. Women showed higher activation in the fusiform gyrus while viewing high-caloric pictures in the hungry state. This study shows that the calorie content of food pictures modulates the activation of brain areas related to reward processing and even early visual areas. In addition, satiation seems to influence the processing of food pictures differently in men and women. Even though an implicit task was used, activation differences could also be observed in the orbitofrontal cortex, known to be activated during explicit stimulation with food related stimuli. © 2010 Elsevier B.V. All rights reserved. Keywords: fMRI Obesity Gender Food reward 1. Introduction Obesity is generated by an energy imbalance and associated with excessive food intake. Eating behavior itself is modulated by physiological, psychological and cognitive factors, e.g. motivational salience of the stimuli, satiety and gender. This clearly indicates that a basal brain control circuit like the hypothalamus, the major homeostatic control center, alone is BRAIN RESEARCH 1350 (2010) 159 – 166 ⁎ Corresponding author. MEG-Center, University of Tübingen, Otfried Müller Strasse 47, 72076 Tübingen, Germany. Fax: + 49 7071 295706. E-mail address: sabine.frank@med.uni-tuebingen.de (S. Frank). 1 These authors contributed equally to this work. 0006-8993/$ – see front matter © 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.brainres.2010.04.030 available at www.sciencedirect.com www.elsevier.com/locate/brainres