Automatic attentional capture by food items in a visuospatial attention task – A study with event-related brain potentials

The incentive sensitization theory suggests that repeated exposure to rewarding substances or food shapes neural circuits to create an attentional bias towards these stimuli. There is ongoing debate about whether attentional capture by such stimuli is an early automatic process or a later stage in the processing cascade. Event-related brain potentials (ERPs) provide a means to pinpoint the timing and location of attentional capture. ERPs were recorded from 28 normal weight healthy women as they attended to the left or right hemifield of a visual display while fixating a central point. Stimuli comprised bars presented left and right of the fixation point simultaneously with the task being to respond to slightly smaller bars on the attended side by button press. The bars appeared superimposed on task-irrelevant distractor stimuli (either food pictures or pictures of non-food objects). The bilateral stimuli elicited a positivity that was largest as posterior sites contralateral to the attended hemifield between 75 and 250 ms. Critically, this contralateral attention effect was enhanced by food distractors on the attended side and diminished by food distractors on the unattended side, demonstrating signs of attention capture by food stimuli as early as 80 ms poststimulus.