Dispensing apparatus for use in a cued food delivery task

Neurobiological models of obesity postulate that obese individuals have difficulty regulating food intake partly because they attribute excessive salience to stimuli signaling food availability. Typically, human studies that investigate the relationship between brain responses to food-related stimuli and obesity present food cues without subsequent delivery of food. However, in order to identify the brain correlates of cue reactivity, we must record brain responses to food-related cues signaling food availability. Therefore, we have developed a dispensing apparatus for use in a cued-food delivery task in which event-related potentials (ERPs) to food-related images predicting food delivery and images not predicting food delivery can be recorded. Here, we describe a method where:
• The experimental apparatus dispenses an edible item (i.e., a chocolate candy) which may or may not be eaten, or a non-edible control item (e.g., a plastic bead).
• Deposit boxes are available to store uneaten candies and the non-edible control items.
• The dispensing mechanism is capable of recording the exact timestamp when each delivery event occurs (e.g., release from the dispenser, arrival in the receptacle, storage in the deposit box).

Representative diagram of the experimental setup. The laboratory control computer (A) triggers the dispensing device (B) to dispense either a food (candy) or non-food control item in the delivery receptacle (C). The participant may either eat the candy, or deposit the candy or non-food control item in the appropriate deposit box (D). The display of the master laboratory computer (A) is mirrored in the participant laboratory room (E), and displays pictorial stimuli predicting either the food reward or non-food control item. During the experiment, the electroencephalogram (EEG) is being recorded and is displayed on a computer (F) in the laboratory control room. The master computer (A) sends triggers to the EEG computer (F) to allow subsequent time-locking of events. Blue arrows represent information flow from the participant laboratory room to the laboratory control room. Black arrows represent information flow from the laboratory control room to the participant laboratory room.Figure optionsDownload as PowerPoint slide