The Heart, Mind and Spirit
The concept of mind is of central importance for psychiatrists and psychologists. However, little attention has been paid in most formal textbooks to this important issue, which is usually studied under the section of ‘Philosophical aspects of psychiatry/psychology’. The practicing psychiatrist should have some working model of the mind to help him understanding his patient’s problems (Salem, 2004). This review discusses some aspects of the components of mind, which is only one step on a long road.
In many cultures throughout history, the heart has been considered the source of emotions, passion and wisdom. Also, people used to feel that they experienced the feeling or sensation of love and other emotional states in the area of the heart. However, in the past, scientists emphasized the role of the brain in the head as being responsible for such experiences. Interestingly, recent studies have explored physiological mechanisms by which the heart communicates with the brain, thereby influencing information processing, perceptions, emotions and health. These studies provided the scientific basis to explain how and why the heart affects mental clarity, creativity and emotional balance. In this review, I shall try to summarize and integrate the interesting findings in this area.
Heart and emotions
It is long known that changes in emotions are accompanied by predictable changes in the heart rate, blood pressure, respiration and digestion. So, when we are aroused, the sympathetic division of the autonomic nervous system energizes us for fight or flight, and in more quiet times, the parasympathetic component cools us down. In this view, it was assumed that the autonomic nervous system and the physiological responses moved in concert with the brain’s response to a given stimulus (Rein, Atkinson, et al, 1995).
The heart and brain
However, following several years of research, it was observed that, the heart communicates with the brain in ways that significantly affect how we perceive and react to the world. It was found that, the heart seemed to have its own peculiar logic that frequently diverged from the direction of the autonomic nervous system. The heart appeared to be sending meaningful messages to the brain that it not only understood, but also obeyed (Lacey and Lacey, 1978). Later, neurophysiologists discovered a neural pathway and mechanism whereby input from the heart to the brain could inhibit or facilitate the brain’s electrical activity (McCraty, 2002)
The brain in the heart:
After extensive research, Armour (1994) introduced the concept of functional ‘heart brain’. His work revealed that the heart has a complex intrinsic nervous system that is sufficiently sophisticated to qualify as a ‘little brain’ in its own right. The heart’s brain is an intricate network of several types of neurons, neurotransmitters, proteins and support cells similar to those found in the brain proper. Its elaborate circuitry enables it to act independently of the cranial brain – to learn, remember, and even feel and sense. The heart’s nervous system contains around 40,000 neurons, called sensory neurites (Armour, 1991). Information from the heart - including feeling sensations - is sent to the brain through several afferents. These afferent nerve pathways enter the brain at the area of the medulla, and cascade up into the higher centres of the brain, where they may influence perception, decision making and other cognitive processes (Armour, 2004).
Thus, it was revealed that the heart has its own intrinsic nervous system that operates and processes information independently of the brain or nervous system. This is what allows a heart transplant to work. Normally, the heart communicates with the brain via nerve fibres running through the vagus nerve and the spinal column. In a heart transplant, these nerve connections do not reconnect for an extended period of time; in the meantime, the transplanted heart is able to function in its new host only through the capacity of its intact, intrinsic nervous system (Murphy, et al, 2000)
The heart’s magnetic field:
Research has also revealed that the heart communicates information to the brain and throughout the body via electromagnetic field interactions. The heart generates the body’s most powerful and most extensive rhythmic electromagnetic field. The heart’s magnetic component is about 500 times stronger than the brain’s magnetic field and can be detected several feet away from the body. It was proposed that, this heart field acts as a carrier wave for information that provides a global synchronizing signal for the entire body (McCraty, Bradley & Tomasino, 2004)