Scientists have unraveled the process of human brain of interpreting emotions by turning feelings into codes.
Cornell University neuro-scientist Adam Anderson, the senior author of the study, discovered that fine-grained patterns of neural activity within the orbitofrontal cortex (OFC), an area of the brain associated with emotional processing, act as a neural code which captures an individual's subjective feeling.
Anderson explained that it appeared that the human brain generates a special code for the entire valence spectrum of pleasant-to-unpleasant, good-to-bad feelings, which can be read like a 'neural valence meter' in which the leaning of a population of neurons in one direction equals positive feeling and the leaning in the other direction equals negative feeling.
For the study, the researchers presented participants with a series of pictures and tastes during functional neuroimaging, and then analyzed participants' ratings of their subjective experiences along with their brain activation patterns.
Anderson's team found that valence was represented as sensory-specific patterns or codes in areas of the brain associated with vision and taste, as well as sensory-independent codes in the orbitofrontal cortices (OFC), suggesting that representation of our internal subjective experience was not confined to specialized emotional centers, but may be central to perception of sensory experience.
They also discovered that similar subjective feelings resulted in a similar pattern of activity in the OFC, suggesting the brain contains an emotion code common across distinct experiences of pleasure. Furthermore, these OFC activity patterns of positive and negative experiences were partly shared across people.
Anderson concluded that despite how personal the feelings were, the evidence suggests that brains use a standard code to speak the same emotional language.
The study is published online in Nature Neuroscience.