Scientists have found the region of the brain responsible for a person’s ability to deal with new problems while studying patients with brain damage.
Researchers, led by experts from the National Hospital for Neurology and Neurosurgery in London, “mapped” the brains of 247 patients who had damage from strokes or tumours and compared them to 81 people who had no brain damage.
Experts from the UCL Queen Square Institute of Neurology and Department of Neuropsychology at the hospital, which is part of University College London Hospitals, said their study has identified the key brain regions that are essential for logical thinking and problem-solving.
Researchers then developed new tests to assess a person’s reasoning skills – their ability to comprehend, draw conclusions, and deal with new and novel problems.
The tests include a verbal analogical reasoning task – a type of puzzle where people are asked to find relationships between words to solve problems – and a deductive reasoning task – where people use pictures, shapes or numbers to figure out logical patterns and solve problems.
Performance in these tests was linked to “lesion-deficit mapping” – a tool used to identify brain areas which, when damaged, are associated with a specific deficit.
People with damage to the right frontal lobe had a much harder time on both tests compared with those with damage in other areas, making around 15 per cent more mistakes than the other patients and healthy individuals.
Lead author Dr Joseph Mole, from the UCL Queen Square Institute of Neurology and Department of Neuropsychology at University College London Hospitals, said: “Our study explores how the front right part of the brain helps people think and solve new problems.
“It also shows that our two new tests can help detect reasoning problems in individuals with brain damage, improving diagnosis and treatment.”
Senior author Professor Lisa Cipolotti said: “By combining a detailed cognitive investigation in a large sample of brain-damaged patients with advanced lesion mapping techniques, we have deepened our understanding of the complex and, so far, poorly understood neural structures underlying human reasoning.
“Our findings show a close connection between the right frontal brain network involved in reasoning and the right frontal brain network essential for fluid intelligence – our ability to solve problems without prior experience.
“This suggests that a common area of the brain plays a critical role in both reasoning and fluid intelligence.”
Writing in the journal Brain, the authors said their study found that the right frontal network of the brain is “critical” for “aspects” of analogical reasoning and deductive reasoning.
The researchers said the two new tests can help identify cognitive impairments which would otherwise go undetected.
“To date, only a very small number of clinical tests have been shown capable of detecting right frontal lobe dysfunction,” they wrote.
After further validation, the tests could be made available on the NHS, which the experts say will address unmet need for tools designed to test for right frontal lobe dysfunction.
