Does it take a consciousness to feel?

UZH News

There are people who feel their own heartbeat particularly well. This ability to perceive varies from person to person and is a facet of interoception, our sixth sense, so to speak, about the processes and conditions in the body. Sensory cells continuously generate information distributed over the organism about the movements of the organs, the pressure on the vessels, the orientation in space and the heartbeat. Millions of impulses continuously reach the brain and generate a feeling for the body of which we are only partially aware.

An increasing number of scientists are now of the opinion that these internal body signals are the prerequisite for the development of the sense of self and the self-confidence that characterizes people. “The way we experience our consciousness depends to a large extent on the sensory body signals,” says Bigna Lenggenhager, Professor of Cognitive Neuropsychology at UZH, who researches the physical self and the development of self-perception.

Descartes' mistake

The American neuroscientist Antonio Damasio is a pioneer in this field of embodiment of consciousness. In the 1990s, with his book "Descartes’ Error ", he derived an evolutionary biological theory of ego-consciousness that contradicts the theses of the 16th century philosopher and mathematician René Descartes. He had viewed the body and the soul as different entities, with the pineal gland - a small organ in the middle of the brain - mediating between the two.

Damasio no longer needs this dualism between body and soul. He explained how the information about the biochemical and physical body functions became more and more integrated in the course of the development of the organisms. They eventually formed the brain stem, where an unconscious and rudimentary proto-self was generated. In the following millions of years, higher cognitive functions developed in our genus Homo in the cortex above the brain stem, with which we reflect and influence behavior. I-consciousness emerged, along with language and memory. These abilities are located in different, networked brain regions, and the body's sensory inputs are projected onto them. “The integration of the signals leads to a coherent sense of self,” says Lenggenhager.

Influence of altered body awareness

In her research, the neuropsychologist focuses on how changed body perceptions affect the experience of the ego. On the one hand, the researcher would like to understand the self-awareness better, on the other hand, it will open up new ways of treating people with body schema disorders in the future. With these diseases, those affected perceive parts of their body as distorted or distorted; an extreme form is xenomelia, in which limbs are experienced as foreign and not accepted.

The body and states of consciousness are apparently much more closely related than was assumed just a few years ago. External influences such as the social environment and family development naturally remain important. Psychoactive substances such as drugs can also change the biochemical communication between brain cells and areas and disrupt self-perception.

Heartbeat and sense of self

As an object of perception, however, the body provides new explanations and theories for long-cherished puzzles. For example, for the feeling of continuity of personal identity that concerns consciousness researchers. We wake up every day and feel that we are the same person throughout our lives. It is speculated that uninterrupted organ signals such as the heartbeat could be the basis of the sense of self. The heart would then not only be the body's engine that pumps oxygen into the blood vessels, but also the refuge of our lifelong, conscious identity.