Heart and brain asymmetry: linked?

The human brain is one of the most complex organs in the world, and eating food consumes a lot of the energy people take in (about 20% of daily calorie intake). To increase energy efficiency, the brain has what is called asymmetry in the brain. Brain asymmetry is essentially a division of labor between two halves of the brain. For example, language is processed by most people on the left side of the brain, and processing face and space Note It is performed in most people by the right hemisphere.

By specializing in performing certain tasks, you need a brain that requires less energy to do these things than if both half are performing them at the same time. The broad form of brain asymmetry is the dominant hand. Approximately 90% of people are right-handed, indicating control of the motor cortex in the left half of the brain (the left half of the brain controls the right side of the body and vice versa). A major unresolved question in psychological research on brain asymmetry is how they developed.

New research into brain asymmetry in patients with organ placement switching

One theory of how brain asymmetry develops is that they are influenced by the same developmental factors ( gene) It also determines the asymmetry within the body. Some organs show asymmetry in placement in our bodies. Most notably, the heart is on the left side in almost everyone, and the liver is on the right side, but there are even more subtle asymmetry. Interestingly, not all people have a heart on the left side, and no liver on the right side. There is a very rare condition called Situs inversus totalis, where the asymmetry of all organ placement is switched. Therefore, a person with Situs Inversus totalis has a heart on the right side and the liver has a liver on the left side.

New research in the journal of neuroscience Brain structure and function It focuses on comparing the brain asymmetry of a person in Situs Inversus totalis with a control volunteer person with normal organ positions (Carlson and colleagues, 2025). Research into Swedish Neuroscientist Emma M. Carlson and her research team used advanced neuroimaging techniques to scan 21 brains, featuring Situs Inversus Totalis and 21 control volunteers. Specifically, we used a technique called Fixel-based analysis of magnetic resonance image diffusion data.

What did the scientists find?

Using this technique, scientists were able to assess various asymmetry in the white matter of the brain. Along with the gray matter (the cell bodies of neurons), the white matter constitutes most of the brain’s mass. It consists of connections between different brain regions. Both groups showed many prominent asymmetry in the white matter, some to the left and some to the right. For example, some of the arcuate bundles, an important connection in the language system, showed strong left asymmetry, reflecting the fact that in most people language is processed by the left half of the brain.

Interestingly, there was no difference between the groups at all. People with Situs Inversus totalis almost rivaled the brain asymmetry to those of control volunteers. This means that the developmental processes associated with the development of organ placement asymmetry do not control brain asymmetry. Instead, it appears that two different types of processes control the asymmetry of these two forms. This is an important insight from this study.