Heart Rate: A Window to the Brain?

Jim Ha, PhD, CAAB

I recently attended a conference of companion animal behavior practitioners and researchers, held in New Orleans this past March (see earlier blog entry). One of the most interesting, and most important, presentations at the three-day meeting was titled, “Assessing Behavior and Training Methods Using Physiological Measures.” This was a summary, and a very interesting demonstration, of the work by Nancy Williams, Peter Borchelt, Alice Moon-Fanelli, and Megan Bulloch that has suggested that heart rate, a relatively easy measurement in awake (ie, behaving!) animals, can provide insight into the activity of the brain.

The logic comes from some similar work in humans, and goes like this: good, healthy behavior is flexible behavior, that is, behavior which exhibits an appropriate selection of responses to stimuli, and that shifts as appropriate. This sort of behavior suggests that if a brain function known as inhibition is working properly: the dog or cat can turn behavior on and off.

The area of brain that is responsible for inhibition is connected to the heart via the vagal nerve, where it helps to control heart function. Heart rate variability (HRV) is the increase and decrease of heart rate in reaction to the changing environment, and HRV reflects the degree of inhibition that has developed in the brain. Thus, high HRV (a very responsive heart/brain) is good. Low HRV in humans is associated with increased mortality, and the likelihood of diabetes, depression and suicide, epilepsy, alcohol abuse, stress, panic disorders, and Generalized Anxiety Disorder. Thus, the brain is important in behavior and HRV is a way to monitor brain (inhibitory) functioning. Neat idea, huh?

So what are the findings: how is HRV and behavior associated in dogs? The work is only in its very earliest stages, but Dr. Williams and her colleagues have found that low HRV is associated with both aggressive and stress behaviors in dogs. She feels that by recording HRV in client dogs, we might gain a much stronger insight into the causes of problem behaviors, and ultimately, the effectiveness of our behavior modification tools. And with the advent of new tools for recording heart rate data, adapted from the sports and fitness business, like the $370 Polar Watch, we can record this kind of data in active animals under natural conditions. Don’t be surprised in the near future if we ask you for permission to fit your dog with a strap-on Polar Watch while we observe their behavior or expose them to behavior modification procedures!