The Brain Functional Networks Associated to Human and Animal Suffering Differ among Omnivores, Vegetarians, and Vegans

Based on MRI of 20 omnivores, 19 vegetarians, and 21 vegans, researchers found differences in brain responses among these groups when exposed to photographs depicting conditions of human and/or animal suffering. Specific observations include the following:

• During human negative valence scenes, vegetarians and vegans had increased activity in the anterior cingulate cortex and inferior frontal gyrus, compared with omnivores.
  
• During animal negative valence scenes, vegetarians and vegans had decreased amygdala activation and increased activity in the lingual gyri, left cuneus, posterior cingulate cortex and other areas in the frontal lobes.
  
• There were different responses between vegetarians and vegans as well. During human negative scenes vegetarians showed "selective recruitment of the right inferior parietal lobule and prevailing activation of the ACC" while vegans showed increased activation of the inferior prefrontal cortex.