In a recent study, researchers highlighted the activity of neurotransmitters in the human brain while processing the emotional aspects of language, shedding light on how individuals discern the meaning of words.
In a groundbreaking study published in the journal Cell Reports, scientists have demonstrated that neurotransmitters in the human brain are activated when processing the emotional content of language, offering fresh insights into how we interpret the significance of words.
This research, led by scientists from Virginia Tech in collaboration with an international team, enhances our understanding of the impact language has on human decisions and mental well-being.
The study was led by Read Montague, a computational neuroscientist and professor at the Fralin Biomedical Research Institute at Virginia Tech, who also directs the Center for Human Neuroscience Research. This groundbreaking exploration examines how neurotransmitters deal with the emotional facets of language—something uniquely human.
This discovery, now available online and featured in the January 28 issue of Cell Reports, merges biological processes with symbolic meaning, associating neural mechanisms that have evolved for survival across many species with the depth of human emotion and communication.
“People generally think of brain chemicals like dopamine and serotonin as signaling positive or negative experiences,” Montague stated, who is both a co-corresponding and co-senior author of the study. “However, our findings indicate that these chemicals are released in specific brain areas when we engage with the emotional meaning of words. Broadly speaking, this research suggests that brain systems evolved to help us respond to favorable or adverse environmental cues might also influence our interpretation of language, which is crucial for our survival.”
The research team was the first to measure the simultaneous release of dopamine, serotonin, and norepinephrine in humans, examining the complex brain dynamics involved in interpreting and responding to language.
Neurochemical levels were recorded from patients undergoing deep brain stimulation surgery for conditions like essential tremor or for implanting leads to monitor seizures in epilepsy patients. These procedures target different brain regions: the thalamus and the anterior cingulate cortex, respectively.
While participants saw emotionally charged words displayed on a screen, carbon fiber electrodes were used to record activity in the thalamus, while standard platinum-iridium electrodes collected data in the anterior cingulate cortex.
The researchers found that words—whether positive, negative, or neutral—affect neurotransmitter release. By observing the rapid dynamics of these releases, they noted distinct patterns related to emotional tone, specific anatomical regions, and the brain hemisphere involved.
“The most surprising finding was from the thalamus,” remarked William “Matt” Howe, an assistant professor in the Virginia Tech School of Neuroscience. “This region wasn’t previously considered significant for processing language or emotional content, yet changes in neurotransmitter levels occurred in response to emotional words. This implies that areas not traditionally connected to emotional or language processing may still process such information, suggesting that brain regions involved in movement might also benefit from emotionally charged information to guide actions.”
While the main insights were derived from human subjects, experiments on animal models further supported the findings.
Alec Hartle, a co-first author and doctoral student in Howe’s lab at the School of Neuroscience, utilized optogenetics in rodent models to validate the observed patterns in humans. This approach employed light to manipulate genetically altered cells, enabling researchers to investigate specific neuron functions and their circuits.
The new discoveries build on earlier research published in Nature Human Behavior, where this research group examined the roles of dopamine and serotonin in social behavior.
Though still in its early stages, the study is significant in its foundational contributions and the questions it raises for future inquiries.
The words analyzed in the study came from the Affective Norms for English Words (ANEW) database, which categorizes words by their emotional valence—positive, negative, or neutral.
