Can your heart think?

A number of years ago, Claire Silvia from Boston, USA, had a heart transplant. Pretty soon she started to experience strange things. “It was like a whole new rhythm, a whole new feeling,” she explains. And when a journalist asked her, soon after the transplant, what she now wanted most in the world, the words “I’d die for a beer right now!” suddenly popped out of her mouth, much to her embarrassment and surprise – she didn’t previously even like beer! “Little by little,” she says, “other things started happening until I was convinced I was living with the presence of another within me.” Claire not only noticed changes in her tastes, her preferences for foods and drinks, but even in her handwriting. All she knew of the person who had donated her heart was that he was a young man who died in a motorcycle accident, strict confidentiality rules mean that organ recipients aren’t allowed to know the details of their donor. Then one night she dreamed of her donor, and the name ‘Tim L’ popped into her mind. The next day she rang her transplant co-ordinator and told her about the changes she had experienced, and asked her if her donor’s name was in fact Tim L. There was silence on the other end of the phone, and then the co-ordinator said “Please don’t pursue this.”

It turned out that her donor’s name was in fact Tim Lamarand.

Throughout most of Human history people didn’t locate their thoughts and emotions within the brain. For example, the ancient Egyptians didn’t even see fit to preserve the brains of their kings and queen’s in the same way that they did with other organs when mummifying them. But while it wasn’t until recently that the brain was identified as the seat of our thoughts, emotions or soul, then where did the ancients believe was the centre of these things? The answer is the heart.

Today we laugh at the notion that our hearts could be intelligent, we see them as basic pumps. A pump doesn’t have thoughts, emotions and memories. But perhaps we don’t know as much as we think we do. For example, our modern association of thought and emotion with the brain may have gone a bit too far.

One association with the heart that we have still kept, to some extent, is that its something to do with our emotions, particularly with love – the heart remains a popular visual symbol of love. Also it’s often used as a symbol for our intuition and morals. We often use phrases like “listen to your heart.” Or “follow what your heart tells you is right.” Admittedly, most people when using these phrases are not always literally asking you to stop and try and sense how your heart feels, they are using the word ‘heart’ as a metaphor for your intuition. But could that metaphor for locating feelings and emotions in the heart actually have some reality to it?

Well, at the most basic level, we know that emotional stress can harm the heath of our hears, putting them under strain, and perhaps leading – in extreme cases – to people suffering heart attacks, as the end product of years of chronic stress. Also, the heart regulates the blood flow, and blood contains hormones and neuro-peptides which transmit emotional information. But could there be a stronger connection than this?

Amazingly, Dr Andrew Armour, a neurologist from Montreal, Canada, discovered a small but complex network of neurons in the heart, which he has dubbed ‘the little brain in the heart’. These neurons seem to be capable of both short and long term memory. Why should the heart even have neurons and the ability to remember? Well, for one thing, there is a lot of muscle co-ordination that goes on in the heart in order to allow it to function properly. The fact that hearts can even be transplanted shows that there is a long-term memory stored in the heart for its rhythms. When a heart is removed, it is cooled and can stay alive for up to four hours. Once the heart is connected into its new recipient, as blood enters it, it begins to beat again. It is almost certainly the ‘little brain in the heart’ that is enabling the heart to remember how to beat.

Furthermore, there is a lot of communication that occurs between the heart and the brain. There are 40,000 neurons in the heart which communicate with the brain. Hormones from the heart travel in our bloodstream. Every time the heart beats, it creates both pulse waves of pressure, and of electromagnetic energy which travel through the body and to the brain. Amazingly, the heart generates a magnetic field 5000 times more powerful than that of the brain. It can be measured six feet away from the body. It almost certainly extends further, but this is the limit of our current sensing equipment.

We all too often forget that the brain is just the most complex end of a whole nervous system which extends throughout our body. For example, the nerves in our hands are in almost constant communication with our brains, a fact that leads some to believe that the ancient art of palm-reading may have some validity: if the nerves on our hands are constantly communicating back and forth with our brains, then its not an unreasonable stretch of the imagination to wonder if our personalities could imprint themselves on the lines of the skin of our palms. Similarly, our hearts are also in constant communication with our brains. Could a similar effect be occurring with the heart? Could the 10-15% of heart donation recipients who – like Claire Silvia – experience changes in their tastes, personalities and memories be picking up on information on the heart’s original owner that was stored in the heart itself?

Gary Schwartz, a professor of psychology and psychiatry at Yale university believes so. He has developed a theory that could explain how the heart learns and remembers. Schwartz points out that all that is required for a system to be able to learn is that it has dynamic feedback: the outputs feed back to the inputs. Any such system that has feedback can learn. As the brain and the heart have feedback – both through neurons and through the bloodstream – the heart can in theory learn. Schwartz, in collaboration with Professor Paul Pearsall, a cardioneurologist from the University of Honalulu (and author of ‘The heart’s code’), collected a number of case studies of heart donation recipients who have experienced these unusual changes. Among them is the case of a 47 year old white man who received the heart of a young black man. Whilst the 47 year old was not racist, he did have a number of underlying assumptions about what kinds of tastes a young black man would have. He joked that if his tastes had changed, perhaps he would now start to like rap music! But what actually happened was the man became obsessed with classical music, and would listen to it over and over. It turned out that the young black man had in fact been a classical violin player. Another heart recipient suddenly became obsessed with competitive cycling and swimming, and began training for, and eventually winning competitions at these sports. One year later he discovered his donor had been an athletic Hollywood stuntman.

Whilst there are a number of scientists and doctors who are now convinced that these types of stories could point to the reality of ‘heart memories’, there are many who also remain sceptical. They argue that there are alternative explanations.

One explanation that’s been put forward for these strange experiences is that the drugs that the person has to take so that their immune system doesn’t reject their new transplanted heart (immunosuppressants) are causing some kind of psychological effect that makes a person believe they are accessing memories from the organ, particularly as even having a deceased person’s heart in your body might play on your imagination. However, while this explanation would account for having some kind of psychological effect, it doesn’t account for the accuracy of the information that such heart recipients have come out with. This accuracy is all the more impressive considering that hospitals maintain a policy of not telling the recipient or their family any of the personal details of who their donor was.

Another theory is that the patient manages to pick up enough information from the medical staff around them to piece together – perhaps even subconsciously – some basic details of their donor. It may even be that conversations that doctors and nurses have while the patient is anesthetized are somehow being absorbed by their mind, below the level of conscious awareness. This is certainly plausible, yet in most of the documented cases it’s been confirmed that the surgical team had not discussed patient details whilst performing the operation, and indeed it would be highly unusual for such a discussion to take place.

There may be many orders of magnitude far fewer neurons in the heart than the brain, but many simple animals such as insects can display intelligent behaviour and memory with a relatively small number of neurons. So perhaps this is also true of our hearts? Ironically, the kind of feedback that Dr Swartz says is present between the heart and brain and is responsible for heart-memories is the very thing that’s currently lacking in the scientific world on this issue, and is holding back our understanding of it. We need feedback from all heart donor cases, we need much more study on this area in order to finally understand whether hearts can remember. Simply ignoring this possibility will block us from ever understanding it.

And if it turns out that our hearts can remember, I think many more people would find comfort in knowing that a part of their dead relative’s personality was living on in the recipient. Some may even chose to meet the recipient and place their hand on their chest to once again feel the heart-beat of the person they loved. It may also encourage more people to carry a heart donor card.