At first glance, the human body looks symmetrical: two arms, two legs, two eyes, two ears, even the nose and mouth appear to be mirrored on an imaginary axis dividing the faces of most people. And finally, the brain: it is divided into two halves that are roughly the same size, and the furrows and bulges also follow a similar pattern.

But the first impression is deceptive: the different brain regions have subtle yet functionally relevant differences between the left and right sides. The two hemispheres are specialized for different functions. Spatial attention, for example, is predominantly processed in the right hemisphere in most people, while language is largely processed in the left. This way, work can be distributed more effectively to both halves and thus the range of tasks is expanded overall.

But this so-called lateralization, the tendency for brain regions to process certain functions more in the left or right hemisphere, varies from person to person. And not only in the minority whose brains are specialized mirror-inverted compared to the majority. Even people with classically arranged brains differ in how pronounced their asymmetry is.

A team of scientists is using the tools offered by the HBP’s digital research infrastructure EBRAINS to address one of the oldest enigmas in neuroscience: the dichotomy of brain structure and function.

Every human brain is different. But even with structural differences, individual brains function in a similar way. In other words, there are functional brains based on completely different configurations. At the same time, a structural change may cause loss of function in one brain, but have no consequences in another individual. Or a drug cocktail may be efficient for one patient, and have no effects for another.