About this Article, “Rightward dominance in temporal high-frequency electrical asymmetry corresponds to higher resting heart rate and lower baroreflex sensitivity in a heterogeneous population”
This article by Professor Charles Tegeler and colleagues (Brain and Behavior, Vol. 5, No. 6), is one among many publications from the Department of Neurology at Wake Forest School of Medicine, investigating relationships between stress and health, and the results of health care intervention based on noninvasive neurotechnology.*
Scientific Background: The human stress response system includes both “fight or flight” and “rest, digest, or freeze” tendencies. The “fight or flight” response is typically activated when people experience an arousing stressor, and it may be associated with faster heart rate as well as changes in attention, emotion, behavior, digestion, immunity, and other systems. In contrast, the “freeze” response, or a “shutdown” state, may be activated when a threat is prolonged or overwhelming, and it may manifest as depressed heart rate, low energy, emotional numbing, and related changes. Previous research had shown that these response tendencies are associated with different sides of the brain, with the right side being the primary manager for “fight or flight” responses, and the left side for “freeze” responses. However, these findings had been largely confined to studies in surgical patients, studies of patients with brain damage, animal experiments, or other very specific contexts.
What This Study Adds: This study compared brain electrical asymmetry scores based on recordings from the left and right temporal lobes, with measures of heart rate and blood pressure, from 131 individuals with a wide range of health conditions. When subjects with rightward versus leftward asymmetry in temporal lobe high frequency rhythms were compared to one another, those with rightward dominance had higher resting heart rate, suggesting that their stress response was oriented toward “fight or flight.” Rightward dominant subjects also showed smaller changes in their heart rate response to changes in blood pressure, suggesting less flexibility of the heart to adapt to changing circumstances. The authors concluded that it appears possible to use brief recordings from the left and right sides of the brain as a way to identify the tendency for a “fight or flight” response.
Why This Study is Meaningful: Maladaptive stress response patterns contribute to a large burden of suffering in mental and emotional health, physical disorders, and behaviors and social relations. This study supports the idea that upstream brain sources for stress responses may be evaluated through a rapid and noninvasive approach. Furthermore, effective interaction with these brain regions could represent a path to advanced intervention on the stress response system. A figure from this article, that illustrates rightward dominance in temporal lobe high frequency activity, was chosen to be the cover image for the issue of Brain and Behavior in which it was published.
*More information about the HIRREM Research Program at Wake Forest School of Medicine, PI Professor Charles Tegeler, M.D., is available at www.wakehealth.edu/hirrem. The Program has received nearly $3.5 million in independent funding since 2011, from the Susanne Marcus Collins Foundation, Inc., the United States Office of the Secretary of Defense through a contract with US Special Operations Command (USSOCOM), the United States Army Research Office, and others.