New Study Reveals How the Brain Prioritizes Bodily Signals in Conscious Awareness
A new study shows that visual and tactile impressions that are related to our own body are prioritized for reaching conscious awareness. This helps us understand how we develop the feeling that the body is our own – through the brain’s integration of what we see and what we feel.
“We found that the brain gives bodily self-signals priority in conscious processing,” says Henrik Ehrsson, professor at the Department of Neuroscience, Karolinska Institutet, and principal investigator of the study. “This helps explain why our sense of having a body feels so immediate and ever-present.”
The researchers used the well-known rubber hand illusion to investigate how the brain integrates visual and tactile input to create a sense of bodily self. Through advanced computational modelling, they demonstrated that the brain automatically prioritizes signals related to the body, making them more likely to reach conscious awareness.
“The sense of owning our body is crucial for creating and maintaining self-awareness, which in turn is essential for distinguishing between ourselves and the outside world. The question of how the brain creates and maintains this feeling in our conscious experience is relevant not only to neuroscience, psychology, and psychiatry, but also to the philosophy of mind,” says Renzo Lanfranco, lead author of the study and Principal Researcher at the Department of clinical Neuroscience.
The results are also important because they provide insight into a fundamental aspect of human experience – the feeling that the body is our own. This could lead to improved understanding and treatment options for conditions in which bodily identity or self-perception is altered, such as depersonalization, schizophrenia, and body dysmorphic disorder.
The next step in the research is to map out exactly how the brain connects integrated visual and tactile signals to conscious awareness at the neuronal level, and which regions support their emergence into subjective experience. The researchers also aim to investigate what happens when these processes break down.
The study was funded by the Swedish Research Council, the Strategic Research Area Neuroscience, the Göran Gustafsson Foundation, and the EU Horizon 2020 program.
Publication
"Conscious awareness, sensory integration, and evidence accumulation in bodily self-perception", Renzo Lanfranco, Sucharit Katyal, August Hägerdal, Xiaole Luan, Victoria Nos, & H. Henrik Ehrsson, Proceedings of the National Academy of Sciences (PNAS), accepted for publication. [www.pnas.org/doi/10.1073/pnas.2503629122]