Understanding brain hemisphere organization by leveraging individual differences

Many human-defining mental capacities recruit an extensive network of brain regions in both hemispheres, yet are dominantly controlled by one side.

For example, language activates both halves of the brain, but language impairments are more severe, likely and longer-lasting when that function’s dominant hemisphere is damaged.

In spite of being such an important feature of the human brain, hemisphere organization is commonly studied in a fragmented way.

Theories about the benefits of hemisphere organization are incomplete, either focusing solely on the dominant side or non-dominant side.

Another issue hindering progress on understanding hemisphere organization is that individual differences in hemisphere specialization are ignored, despite being massive.

Combined, this led to opposing philosophies for promoting cognitive recovery after one-sided brain damage and one-size-fits-all therapies.

HEMIVAR will help resolve these issues through an original integration of advanced neuroscience techniques (MRI and TMS) and sophisticated network-analysis frameworks, that will allow to study hemisphere organization in the intact and disrupted brain holistically. A major conceptual and methodological innovation is the attention to individual variability in hemisphere organization.

My project will deliver a novel empirically-validated theory that jointly explains the biological roles of the dominant and non-dominant hemisphere (Objective 1) and will clarify how individual hemisphere dominance interacts with between-hemisphere connectivity (Objective 2).

The project's results will constitute a significant advancement of our understanding of the human brain and will generate widely-applicable methodological recommendations for future studies.

On top of that, they will serve as a stepping stone for clinical research on integrating hemisphere specialization into (patient-tailored) brain rehabilitation, in line with the EU research policy aim to promote personalized medicine.