Although feelings are personal and
subjective1, the human brain turns them into a standard code that objectively represents emotions across different senses, situations and even people, reports a new study by Cornell University neuroscientist Adam Anderson. "We discovered that fine-grained patterns of
neural2 activity within the orbitofrontal cortex, an area of the brain associated with emotional processing, act as a neural code which captures an individual's subjective feeling," says Anderson, associate professor of human development in Cornell's College of Human Ecology and senior author of the study. "Population coding of affect across
stimuli3, modalities and individuals," published online in Nature Neuroscience.
Their findings provide insight into how the brain represents our innermost feelings – what Anderson calls the last frontier of neuroscience – and upend the long-held view that emotion is represented in the brain simply by
activation4 in
specialized5 regions for positive or negative feelings, he says.
"If you and I
derive6 similar pleasure from
sipping7 a fine wine or watching the sun set, our results suggest it is because we share similar fine-grained patterns of activity in the
orbitofrontal(眶额的) cortex," Anderson says.
"It appears that the human brain generates a special code for the entire valence
spectrum8 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," Anderson explains.
For the study, the researchers presented participants with a series of pictures and tastes during
functional9 neuroimaging, then
analyzed10 participants' ratings of their subjective experiences along with their brain activation patterns.
Anderson's team found that
valence(原子价) was represented as
sensory11-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, the authors say, that representation of our internal subjective experience is not confined to specialized emotional centers, but may be central to perception of sensory experience.
They also discovered that similar subjective feelings – whether
evoked12 from the eye or tongue – resulted in a similar pattern of activity in the OFC, suggesting the brain contains an emotion code common across distinct experiences of pleasure (or displeasure), they say. Furthermore, these OFC activity patterns of positive and negative experiences were partly shared across people.
"Despite how personal our feelings feel, the evidence suggests our brains use a standard code to speak the same emotional language," Anderson concludes.