Emotional processing of food-related pictures was studied in a series of experiments, comparing participants that revealed unhealthy attitudes toward food, dieting and body shape, with a control group. All subjects were female, and responses to pictures of caloric and healthy food were compared to responses to other emotional stimuli. A subliminal presentation, using a backward masking procedure in order to investigate automatic, non-conscious processing, was also used. Verbal ratings of the pictures and psychophysiological responses (skin conductance and heart rate) were recorded.
The results showed that, in general, food pictures were processed in the same way as other emotional material, both verbally and phychophysiologically. Verbal ratings showed that food pictures can be considered, in general, pleasant stimuli and are not especially arousing. However, some tendencies to a differentiation on processing between groups indicate that participants, selected for being more worried about food, can be more reactive to food cues. Specifically, increased skin conductance responses to food slides could be observed in this group. Concerning the masked presentation, the general pattern was an absence of subliminal effects, however, there were some weak effects that showed that heart rate changes could be modulated by the participant attitudes toward food and body shape, i.e., increased heart rate was observed in the “worried” group to food pictures.