Before you read today’s excerpt, there’s something you should know. Reading affects the left side of your brain. With that in mind, enjoy your reading.
For the study, the researchers worked with 52 individuals between the ages of 57 and 60 who were recruited from the Wisconsin Longitudinal Study – a long-term study of more than 10,000 people who graduated from Wisconsin high schools in 1957. Specifically, the scientists wanted to know if people who showed more activity in the left side of the prefrontal cortex – a part of the brain associated with positive emotional responses – also showed greater immunity to the influenza virus after vaccination.
To answer this question, the researchers vaccinated all the subjects against the flu virus. Before vaccination, they measured the study participants’ brain activity, both at a baseline state and during emotion eliciting memory tasks. During these tasks, the participants were asked to recall two events – one that made them feel intensely happy and another that left them feeling intensely sad, fearful or angry. As the respondents focused on the emotion experienced for one minute, the researchers measured the electrical activity in both the right and left sides of the prefrontal cortex.
Previous studies, notes Davidson, have shown that individuals with greater activity on the right side of this brain region tend to have a more negative affective style, which can cause these individuals to respond inappropriately to emotional events.
The researchers collected these prefrontal cortex activity levels again after the subjects spent five minutes writing about the particular events. At this time, they also measured the participants’ eyeblink reflex in response to sudden noises. This measure, explains Davidson, provides a convenient and objective way to measure how negatively or positively a person reacts to a stimulus.
Three times in the six months following vaccination, the researchers collected serum samples from each subject to track the number of flu-fighting antibodies in the blood, which can determine immune function.
Six months after being vaccinated against the flu virus, the subjects who had greater activity in the left side of the prefrontal cortex, instead of the right side, also had a greater rise in the number of antibodies for influenza, says Davidson.
“This study establishes that people with a pattern of brain activity that has been associated with a positive affective style are also the ones to show the best response to the flu vaccine,” says the Wisconsin researcher. “It begins to suggest a mechanism for why subjects with a more positive emotional disposition may be healthier.”
Source: “Study Shows Brain Activity Influences Immune Function.” By University Of Wisconsin-Madison. http://www.sciencedaily.com