Neurons in the brain region associated with fear react to junk food
Neuroscientist Daeyeol Lee of Yale University registered activity of single neurons in the human volunteers’ brain (amygdala) while images of junk food were presented. About 31 % of all registered neurons were increasing their activity in a predictable way as the individual value of a food increased though there were other neurons in the same region, which activity declined as the value of a food increased (J Neuroscience, January 5 , 2011).
Interestingly, the amygdala is a region that is traditionally associated with memory of emotions, mostly fear and aversive reactions including immobility, tachycardia, increased respiration, and stress-hormone release (“Cytoarchitectonic mapping of the human amygdala, hippocampal region and entorhinal cortex: intersubject variability and probability maps”. Anat Embryol (2005) 210 (5-6): 343–52). However, it’s been shown to participate in the process of Pavlovian conditioning with food as a positive reinforcement (Nature 2005, 439 (7078): 865–870)