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A group of neuroscientists was interested in differences that would occur when vegans, vegetarians, and omnivores would have to watch two different things. The observed results give us some interesting insights about vegetarian and vegan brain activity.Vegetarians, vegans, and omnivores were assigned to do two different tasks.

  • They had to watch neutral, silent videos of people, monkeys, and pigs biting
  • They had to watch neutral, silent videos of monkeys and pigs opening their mouths, or in the case of humans, talking.

This study is a continuation of the first one, which was examining the brain activation when presented with animal suffering.

In a series of different comparisons, here are some of the more interesting findings that were noted:

There was an increase in the right amygdala activity when vegetarians and vegans were watching scenes of people talking, compared to biting. The amygdala, apart from being involved in memory and emotions, is also connected to the analysis of movement in our surroundings. This is due to its connections to other brain areas. Therefore, it can add an emotional charge to information related to activity which we receive and process in our brain.


How is this important?

This could suggest that vegetarians and vegans analyze the actions and intentions of other people in a different way than omnivores, by adding an emotional connotation, which can be pleasant or unpleasant, to things that they see in their social environment.

Vegetarians also had the highest level of brain activity in an area  (right posterior insula)  that gets activated by emotion, by perception, and interoception – how sensitive we are to stimuli that come from the inside of our bodies. This part of the brain also has a regulatory role when it comes to the connectivity of different brain areas. It is involved in social mirroring (when someone copies someone else with movement, gestures etc.) and the ability to empathize with others.

Vegans, however, had higher brain activity in parts of the brain that are included in the  mirror neuron system. This system is a conceptual network of neurons in the brain. It enables us to empathize with others and has also been noted as defunct in people with autism.

Both of the two groups had a higher level of activity in different parts of the brain that are related to empathy. These networks also have a role in the regulation of social interactions with other people. This goes hand in hand with the first study, where they observed that these vegetarians and vegans were more empathetic than omnivores. The results thus show that people, who have a more compassionate response when it comes to animals, probably also have a higher capacity for empathy and related prosocial behaviors in general.


The most interesting parts

Pigs opening their mouths

  • Vegetarians: There was a higher activation in an area (anterior cingulum) related to a strong empathetic response or enhanced attention.
  • Vegans: There was a higher activation in an area (parrahippocampal gyrus) related to emotion-driven learning through its various connections.

These results suggest that vegetarians had the strongest empathetic response, or that they were just the group that exhibited the highest level of interest when pigs were opening their mouth, and that vegans can probably remember information about animals better , as they had the highest activation of a brain area which is related to emotion-driven learning.

And finally:

Trying to speak to animals? Monkeys opening their mouths

  • Vegetarians and vegans had an increased activation in brain areas (bilateral cuneus and left MTG) that have been associated to decoding language and lip reading in a lot of other studies; could this mean that they were trying to decode what the monkeys were saying?
  • Only vegetarians had an increased activation in a particular area (left pars opercularis of the IFG) which could suggest that they were trying to copy the monkeys in opening their mouths.
  • Only vegans had an increased activation in a larger network (associative temporooccipital area) that gets activated when we try to understand what others say – this could suggest that they were trying to understand the monkeys when they were opening their mouths.
  • The same pattern was found when they were watching pigs, however, it was less noticeable.


What does this tell us?

Collectively, these results suggest that vegetarians, vegans, and omnivores show different brain responses when they see animals and humans suffer. They also show a different, and interesting, pattern of activity, where the former two show a pattern of activity related to the idea of increased equality with other animals. At least if we interpret their brain activity in the sense that they were trying to understand what the monkeys and pigs were saying, as well as mimicking their behavior.

So how do you feel about these findings?

The ‘‘vegetarian brain’’: chatting with monkeys and pigs? (2013), Brain Structure and Function

One more thing, before you click away.

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