Your heart and brain, connected

Recently found this amazing Article, which demonstrates how our memory for words can change depending on how our heart is beating.

This article is a fantastic piece on how seemingly impossible details in our physiology can impact cognition.

Here’s how it works: your heart has a very well understood beating pattern, called the “QRS” complex:


Each letter in the above wave form represents a different “event” in the heart beat rhythm.  The diagram above shows a typical heart beat measured using electrocardiogram, which is the electrical charge sent through your heart to manage its beating needs.   The QRS complex, as it unfolds, is a product of the organism’s needs for blood pressure, which is of course governed by the ongoing feeling states of the organism.  What this means is that, the QRS is going to have an impact on how we perceive things happening.

In this study, the authors timed the presentation of words to be memorized with the points in the graph labelled R (cardiac diastole) or to the T (cardiac systole, which is a result of blood pressure sensitive baroreceptor function).  Words presented during systole were less well remembered than the words presented during diastole (point R), indicating that the impulse sent from the blood pressure regulators was actually impacting the ability to hold something in memory.

This finding indicates something amazing to me.  Our cognition is inherently tied to the constantly changing feeling state moving through our bodies.  The finding demonstrates the massive interconnectedness of the nervous system, and the level of detail at which these connections play out.  So while this study doesn’t really tell us about our day to day function, it’s a vivid reminder of how our whole body works together.