That squirrel over there has a funny looking mouth because she is stuffing too many acorns into her cheeks. It’s not a knee-slapper but it makes you want to smile. And when your neighbor takes the garbage out and smiles at you, I bet you smile back. A smile is critical in communication. A lack of smiling can be symptomatic of autism, depression, and schizophrenia. My experiment investigated the difference between brain activity while a person smiles in an interaction with another person and the brain activity while a person smiles from a non-human stimulus. Brain activity of pairs of subjects was recorded with functional near-infrared spectroscopy(fNIRS) while a facial classification device measured the strengths of their smiles. Participants alternated between viewing cute animal videos and the face of their partner sitting across from them. Results showed even though both subjects smiled, smiling from watching a partner smile exhibited brain activity in social brain areas like Wernicke’s and Broca’s areas, and the temporal gyrus. Smiling from watching videos displayed brain activity in brain areas responsible for movement. These findings indicate that social smiles activate a separate system of brain activity that of smiles engendered by non-human stimuli … My claim from using functional near-infrared spectroscopy (fNIRS) brain scanning is that those two smiles are neurologically different. The smile you give your neighbor after she gives one to you, the smile contagion known as the social smile, activates the Broca and Wernicke areas of the brain, as well as temporal gyrus all of which are all associated with communication and social cues. Conversely smiling because of a funny looking squirrel activates areas of the brain such as the motor and parietal cortex, which are responsible for movements and sensations. But why might it be important that there is a distinction between a social contagion smile and just a smile from a cute scene?

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