Study shows way for a second feel your heartbeat

A new study suggests that the deeper meaning of our cardiovascular conditions, our "interoceptive awareness" of the beating heart, is based on two independent channels, contrary to what had been claimed by prominent researchers. The University of Iowa study published online this week in the journal Nature Neuroscience by investigators at the Department of Neurology at the J. Roy and Lucille A. Carver College of Medicine and graduate programs in neuroscience and psychology.

Researchers have found that there is only one way to the insular cortex of the brain - the target of recent research on interoception - an added sense way to contribute to their own heart beat. The second path leads from fibers in the skin of most of the somatosensory cortex, part of the brain involved in mapping out the body and sense of attitude.

The team of UI has also confirmed the widespread belief by researchers that the insula and anterior cingulate (CSF) of brain regions are important, but not necessarily to feel for a person of his own heartbeat . The insula contributes higher order functions such as self-consciousness, while the ACC is believed to regulate the heartbeat.

"What is shown in this study, there may be two ways to participate in the practice of making such representation of these sensations," David Rudrauf, Ph.D., assistant professor of neurology and radiology and director Laboratory of brain imaging and cognitive neuroscience. Rudrauf is the author of the study with Sahib Khalsa, MD, PhD, Doctor of Medicine and received from the user interface and is currently working on his psychiatry at UCLA.

Daniel Tranel, Ph.D., professor of neurology and psychology and director of the residency program post-doctoral fellowship in clinical neuropsychology, and Justin Feinstein, a graduate student in clinical neuropsychology, are co-authors of the study " Paths of interoceptive awareness.

Researchers examined the UI an extremely rare neurological illness called "Roger", the almost complete bilateral insula and ACC damage, but that the primary somatosensory cortex bilaterally intact. They also studied 11 healthy participants matched male portal.

Roger has been studied in the laboratory of the UI for 15 years. His brain damage incurred in 1980 after an episode of herpes simplex encephalitis. With Roger, Rudrauf and his colleagues wanted to see if it is absent from regions of the brain are really need to feel your own heartbeat.

The researchers injected the participants with a synthetic form of adrenaline arrive to take their heart to 25 beats per minute. Subsequently, participants had their turn of a dial on its length moment by moment, experience the intensity of the sensations of his heart beating.

It turned out that Roger was his own pulse, and the healthy participants in a dose-response.

"It was a delayed reaction, but still feel," said Feinstein.

These developments suggested that the insula and ACC are not necessary, strictly speaking, sensations of interoceptive awareness of heartbeats.

The researchers hypothesized that Roger felt his heart because his brain was in a different way, with reference to the effects of heart on the chest wall and pulsations in the blood vessels of the skin stretching. And she applied a topical anesthetic lidocaine on the situation on the skin, where participants said they felt a sensation of maximum heart rate.

She repeated the procedure of injecting the heart of each of the participants has increased. Roger again showed increases in heart rate similar to the comparison of healthy participants. However, under anesthesia, he said it was more his heartbeat. Conversely, participants' ability to compare health, his heart not feel affected by anesthesia.

"There are two ways. One provides the signal for heartbeat of the surface of the chest wall and pulsating blood vessels under the skin, the somatosensory cortex, so that whenever you have your heart rate it stimulates this process, "said Feinstein." Roger is able to feel her heart, because this area of his brain - the somatosensory cortex - is still there. If you get rid of this feeling of anesthesia of the skin, you need areas such as the insular cortex, to feel the heartbeat deep inside. That is lacking in Roger and that is where the healthy person is capable of meaning ".

As noted Rudrauf is, interoceptive awareness, including awareness of our cardiovascular States, is the key emotion, feeling and sense of self. The roads through this study we found may all be involved from the beating heart in a state of panic, feeling "broken heart" in a state of mourning.