The human heart has always been a symbol of love and romance. In reality, however, it is an organ that pumps blood around our bodies.
So where has this emotional connection to love come from?
No other organ in the human body has this connection with an emotion, so could there be something behind the literature and poetry, and if so, could science provide an explanation?
There are some researchers that believe this connection is possible because the human heart has a mind of its own. And these connections are not based on theories, but actual scientific experiments.
But in order to have a mind we have to be able to think, and for that we need neurons. It was once thought that the only organ in the human body to have neurons was the brain, but now we know this is not true.
One researcher to explore this juxtaposition of the human heart as an organ and a symbol of love science documentary filmmaker David Malone. His film “Of Hearts and Minds” examines several experiments, and the results might surprise you.
There are neurons in your heart
We assume that the brain is controlling our emotions, but Professor David Paterson, Ph.D. at Oxford University, disputes this. He says that the brain is not the only organ that produces emotions. This is because the heart actually contains neurons similar to those in the brain, and these fire in conjunction with the brain. The heart and the brain are therefore connected:
When your heart receives signals from the brain via the sympathetic nerves, it pumps faster. And when it receives signals through the parasympathetic nerves, it slows down,
Neurons are associated with thought processes in the brain, but highly specialized ones have been found situated on the right ventricle surface. It begs the question, what are thought process neurons doing in an organ that pushes blood around our body?
These heart neurons can think for themselves
In an experiment, a piece of right ventricle from a rabbit, where these specialized neurons have been found, is placed in a tank with oxygen and nutrients. The piece of heart manages to beat on its own, despite being unattached, suspended and having no blood flowing through it. When Professor Paterson shocks the heart tissue it immediately slows down this beating. Professor Paterson believes that is a direct decision made by the neurons as they respond to the impulse.
The human heart reacts strongly to negative emotions
Health studies have proved that intense anger has an adverse effect on the heart, increasing the risk of a heart attack by five times. Intense grief is also extremely unhealthy. You are 21 more times more likely to have a heart attack the day immediately after you have lost a loved one. Studies have shown that people who have suffered prolonged stressful situations, such as soldiers, combat veterans, doctors, all have higher rates of heart problems than the rest of the population.
On an ECG readout, if we are under stress, our heartbeat shows up in a series of jagged and erratic lines. This is called an incoherent heart rhythm pattern. This means that our autonomic nervous system (ANS) is out of sync with each other. Scientists liken this to driving a car and having one foot on the gas (the sympathetic nervous system) and the other on the brake (the parasympathetic nervous system) simultaneously.
But it also reacts strongly to positive emotions
By contrast, when we experience pleasure, joy or contentment, our heart rhythms become very orderly and look like a smooth wave. Scientists call this a coherent heart rhythm pattern where the two branches of the ANS are completely in sync and working together.
Positive emotions, therefore, have some bearing on our hearts and can actually have healing properties. Studies have shown that in cases of people who had an increased risk of early-onset coronary artery disease, those that showed a happy outlook and cheerful persona had their risk of a heart attack reduced by one-third.
Mind over matter you might think but which mind and where?
The heart also affects your mind
In a final test in the film, Malone looks at images, some neutral and some frightened. Some are synced in time to his heartbeat, and others are not. The results revealed that when he saw the frightened images in sync with his heartbeat he perceived them as being ‘more intensely frightened’ than when he saw them out of sync.
This would suggest that his heartbeat is affecting his mind, and processed a greater reaction in connection with the images and the heartbeat. During the test, researchers mapped the exact area of the brain that was affected by the heart, which was the amygdala.
The amygdala is known as the fight or flight brain structure and processes fear reactions, alongside signals from the heart. In this experiment, however, it is the human heart that is affecting the brain in the first instance.
Malone argues that:
It is our heart working in tandem with our brain that allows us to feel for others… It is ultimately what makes us human… Compassion is the heart’s gift to the rational mind.
Is this just wishful, poetic thinking?
However, there are still some scientists that argue having neurons in the heart does not make it a thinking organ. There are also neurons in the spinal cord and the nervous system, but they do not have minds either.
Some scientists believe the reason for neurons in the heart is that it is a highly specialized organ that requires neurons to regulate and process the extreme demands of the cardiovascular system.
The neurons in the brain are not the same as the neurons on the heart, and having neurons present does not indicate consciousness. The brain consists of an intricate pattern of neurons, organized in a specialized way that allows us to produce cognitive thought.