Cerebral processing of food-related stimuli: effects of fasting and gender.

To maintain nutritional homeostasis, external food-related stimuli have to be evaluated in relation to the internal states of hunger or satiety. To examine the neural circuitry responsible for integration of internal and external determinants of human eating behaviour, brain responses to visual and complex gustatory food-related stimuli were measured using functional magnetic resonance imaging in 18 healthy non-smokers (10 women, 8 men). Each individual was studied on two occasions, the order of which was counterbalanced; after eating as usual and after 24 h fasting.

Differential neural responses to overt and covert presentations of facial expressions of fear and disgust.

There is debate in cognitive neuroscience whether conscious versus unconscious processing represents a categorical or a quantitative distinction. The purpose of the study was to explore this matter using functional magnetic resonance imaging (fMRI). We first established objective thresholds of the critical temporal parameters for overt and covert presentations of fear and disgust.