The word "heart" is one of the most important in religious lan-
guage. In liturgies, we are invited to lift up our hearts, and
often to examine our hearts. It occurs hundreds of times in the
Bible. Spiritual writers refer to the heart as the seat of
religious imagination and contemplation, emotion and knowledge.
Yet modern science sees the heart as merely a mechanical pump.
It is an impressive, highly evolved pump; but still a pump. Hence,
when the word "heart" is used in religious and everyday language,
it is now regarded as mere metaphor. It is no more the most
spiritual member of the body, as the medieval world insisted, any
more than the liver is the most irritable.
This modern view originates with the mechanistic philosophy of
Descartes, which informs contemporary science deeply. The heart
became subject to the same understanding of animate flesh which led
Descartes to believe that the dogs he dissected alive did not feel
pain. They were merely engaged in exaggerated muscular spasms.
But this reductionism could be on the brink of being overturned.
It may be that there is, after all, physiological sense to be made
of the language that links the heart to wisdom and insight,
conscience and courage. A growing body of research suggests that
there may be more than mere metaphor at play in the associations
between the heart and the spiritual, after all.
WE TALK about being "heavy-hearted" or "downhearted", and, in
fact, depression has long been correlated with an increased risk of
heart disease. This is a result of many complex factors, including
the effects of stress hormones and the suppression of the immune
system by depression. But a new link is being made between
heart-rate variability and low moods.
New research, pioneered by Professor Stephen Porges at the
University of Illinois, in Chicago, suggests that heartbeat
responsiveness is a good predictor of emotional health. The child
who has a heart that can react dynamically to, say, a father's
mocking, or a mother's criticism, is likely to be more emotionally
resilient as an adult. In other words, a heavy heart - if by
"heavy" is meant the felt sense of being emotionally unresponsive -
has literally to do with depression.
This much is perhaps not so surprising. We all know that our
heart races when we are shocked or excited. Taking a deep breath
calms us down because it calms the heart. But consider the work of
Professor Hugo Critchley and Dr Sarah Garfinkel at the University
of Sussex. They have shown that individuals are better at
recognising scary-looking faces flashing before them when their
hearts are in the systole or contracting phase of beating.
Other research suggests that the heart helps to mediate the
fine-tuning of various emotional ca- pacities, such as empathy.
Such findings resonate with the notion of "embodied cognition" -
the evidence that our bodies as well as our brains are engaged in
the generation and processing of thoughts and feelings (Comment, 1
February).
There is also an area of research being conducted by Professor
David Paterson of Oxford University, among others. He studies what
is coming to be known as the "heart's brain" - the network of
neurons that surround parts of the heart. It seems that these
neurons have autonomous processing power. They do not merely pass
on signals from the brain. The implication is that the brain and
the heart work in tandem, not as master and slave.
THESE new insights are emerging because the technology now
exists to study more than just the musculature of the heart. It
seems, at the very least, that the heart can recall and compute
responses to its immediate surroundings, as well as cater for the
needs of other parts of the body, such as the limbs.
When you remember that the human body is constantly awash with
sensorimotor patterns and pulses - the heart itself, breathing,
digestion in the gut, physical gesticulations, and locomotion - it
starts to look plausible to think of the heart as the centre of a
dyna-mic, interactive system that helps to make sense of things. If
this embraces our emotional lives, then it includes our
intellectual and spiritual lives, too, since these elements of
understanding cannot easily be separated from one another.
The heart works in tandem with the brain. It has also been shown
that the heart is far more connected to the right hemisphere of the
brain than the left. The right hemisphere is, in turn, more closely
associated with our ability to make intuitive connections; to feel
rather than calculate a way forward; to stay open to the
unknown.
In short, the capacities of the right hemisphere could be said
to be crucial to feeling at home with matters of the spirit. The
implication is that the heart plays a vital part in this, too.
St Ignatius of Loyola writes about God's speaking directly to us
in our hearts. St Augustine speaks of the "piercing glance of the
heart". It now seems that something more than the metaphorical was
being intuited. Next time that you are invited to lift up your
heart, you might remember the most spiritual organ of the body.
That pump seems crucial to enabling you to respond richly.
Mark Vernon is the author of Love: All that matters
(Hodder Education, 2013).