http://www.heartmath.org/research/science-of-the-heart/soh_5.html
under normal physiological conditions, the heart’s intrinsic nervous system plays an important role in much of the routine control of cardiac function, independent of the central nervous system…
It is our experience that the degree of coherence between the mind and emotions can vary considerably. When they are out-of-phase, overall awareness is reduced. Conversely, when they are in-phase, awareness is expanded. This interaction affects us on a number of levels: Vision, listening abilities, reaction times, mental clarity, feeling states and sensitivities are all influenced by the degree of mental and emotional coherence experienced at any given moment.
The results of research studies summarized in this overview, taken together, support the intriguing view that individuals can gain more conscious control over the process of creating increased coherence within and between the mental and emotional systems than might be commonly believed.
Familiar input patterns from the external environment and from within the body are ultimately written into neural circuitry and form a stable backdrop, or reference pattern, against which new information or experiences are compared. According to this model, when an external or internal input is sufficiently different from the familiar reference pattern, this “mismatch” or departure from the familiar underlies the generation of feelings and emotions.
In our internal environment many different organs and systems contribute to the patterns that ultimately determine our emotional experience. However, research has illuminated that the heart plays a particularly important role.
The heart is the most powerful generator of rhythmic information patterns in the human body. As we saw earlier, it functions as sophisticated information encoding and processing center, and possesses a far more developed communication system with the brain than do most of the body’s major organs. With every beat, the heart not only pumps blood, but also transmits complex patterns of neurological, hormonal, pressure and electromagnetic information to the brain and through-out the body. As a critical nodal point in many of the body’s interacting systems, the heart is uniquely positioned as a powerful entry point into the communication network that connects body, mind, emotions and spirit.
Numerous experiments have now demonstrated that the messages the heart sends the brain affect our perceptions, mental processes, feeling states and performance in profound ways. Our research suggests that the heart communicates information relative to emotional state (as reflected by patterns in heart rate variability) to the cardiac center of the brain stem (medulla), which in turn feeds into the intralaminar nuclei of the thalamus and the amygdala. These areas are directly connected to the base of the frontal lobes, which are critical for decision making and the integration of reason and feeling. The intralaminar nuclei send signals to the rest of the cortex to help synchronize cortical activity, thus providing a pathway and mechanism to explain how the heart’s rhythms can alter brainwave patterns and thereby modify brain function.
Our data indicate that when heart rhythm patterns are coherent, the neural information sent to the brain facilitates cortical function. This effect is often experienced as heightened mental clarity, improved decision making and increased creativity. Additionally, coherent input from the heart tends to facilitate the experience of positive feeling states. This may explain why most people associate love and other positive feelings with the heart and why many people actually “feel” or “sense” these emotions in the area of the heart. In this way, as will be explored further in the studies presented in this Overview, the heart is intimately involved in the generation of psychophysiological coherence.
Research has shown that the heart’s afferent neurological signals directly affect activity in the amygdala and associated nuclei, an important emotional processing center in the brain. The amygdala is the key brain center that coordinates behavioral, immunological and neuroendocrine responses to environmental threats. It also serves as the store-house of emotional memory within the brain. In assessing the environment, the amygdala compares incoming emotional signals with stored emotional memories. In this way, the amygdala makes instantaneous decisions about the threat level of incoming sensory information, and due to its extensive connections to the hypothalamus and other autonomic nervous system centers, is able to “hijack” the neural pathways activating the autonomic nervous system and emotional response before the higher brain centers receive the sensory information.”
