Can't take my eyes off you - How task irrelevant pictures of food influence attentional selection

摘要

By means of event-related potentials (ERPs), the present study intended to extend previous findings on how the different processing stages of attentional selection are altered by the participants' motivational state depending on their saturation level. Forty-four normal-weight (mean BMI: 21.34, SD = 1.54), healthy participants aged between 19 and 34 years were assigned to a condition of hunger or satiety. While participants performed a central oddball task, task-irrelevant pictures (food vs. neutral) were presented unilaterally (either left or right from fixation) or bilaterally. Additionally, participants' eating and nutrition behaviour as well as their current level of hunger were assessed by self-reports. The results showed that while on the behavioural level groups did not show any differences in RTs and accuracy, ERPs of hungry participants show an enhanced early parieto-occipital activity 100-200 ms after stimulus onset (N1pc) for food pictures, particularly for high-calorie food. Furthermore, amplitudes of the N1pc co-varied significantly with the participants' subjective feeling of hunger. 200-300 ms after stimulus onset, P2pc in hungry participants reveal a lack of differential processing of the food and neutral stimuli. Between 300 and 400 ms, food pictures were associated with an enlarged centro-parietal positivity (P3) in hungry compared to satiated participants, again especially for high-calorie food stimuli. From the perspective of motivated attention, the results of the present study suggest, that hunger may induce a state of heightened attention for food stimuli, although they were completely irrelevant for the current task. By that, salient food stimuli had an influence on early automatic attentional selection as well as on later and rather intention-driven processes of attentional "de-selection" and stimulus maintenance in normal-weight participants.