Brain Mysteries

Brain picture

In new research that’s been published in Proceedings of the National Academy of Sciences (PNAS), a team of scientists from the Hebrew University Hadassah Medical School unraveled a longstanding mystery of a fundamental property of the brain.  For a long time now, it’s been known that the brain uses topographic organization, or that parts of the brain that make similar types of computations are situated close to each other.  Yet in the case of pathology, these topographies may undergo reorganization.  Researchers have now shown that the continuity of these brain maps is being disturbed, and this continuity can be quantified, which allows them to be used as a biomarker for detecting neuropsychiatric disease.

To understand this relationship, the researchers investigated the role of topographic organizational continuity.  With functional MRI, they studied two types of unique populations: patients with injury to one side of the spinal cord that enabled comparison of disturbed and non-disturbed body sides, and patients going through surgical repair.  Such an approach enabled direct comparison in human patients with respect to their own self or before and after surgical intervention.  Instead of inducing lesions in animals, the team was able to repair the human patients and check them both before and after.  Unlike animals, patients were able to report their subjective experience, which is crucial for understanding high cognitive functions and neuropsychiatry.

The researchers have developed an algorithm that quantifies continuity of the patients’ brain maps.  Their results showed that in each individual patient, pathological processing was reflected by a discontinuity of topographic maps, as opposed to signal reduction.  Such findings have suggested that continuity is a primary principle in brain computation, although in pathological states, the brain could give up on this principle to retrieve as much information as possible, helping this serve as a biomarker for neurological pathologies.  The researchers are now trying to fine-tune their findings in neurosurgical patients in an effort to enable a better, patient-tailored diagnosis and follow-up.  They’ve also been extending their findings to other parts of brain processing, including vision, hearing, number processing and memory.  If you’d like to learn more about what they’ve been doing, feel free to click here!