Brainy scientists identify parts of brain that remembers words

By Stephen Beech

The parts of the brain needed to remember words have been identified.

Those areas are affected by a common form of epilepsy, say scientists.

A team of neurologists and neurosurgeons at University College London (UCL) made the breakthrough.

Their findings, published in the journal Brain Communications, show that shrinkage in the front and side of the brain - prefrontal, temporal and cingulate cortices, and the hippocampus - is linked to difficulty remembering words.

They say the new discovery highlights how the network that is involved in creating and storing word memories is dispersed throughout the brain.

Corresponding author Professor John Duncan said that is particularly crucial for helping to understand conditions such as epilepsy, in which patients may have difficulty with remembering words.

The research team hopes their findings will help guide neurosurgical treatment for patients with epilepsy by helping surgeons to avoid parts of the brain important for language and memory, that may otherwise be affected when conducting operations.

Duncan, of UCL's Queen Square Institute of Neurology, said: “Being able to remember and recall words is important for day-to-day memory to work well.

“Detailed MRI brain scans are used to find out the causes of epilepsy and can show if any parts of the brain are shrunken.

"By measuring the parts of the brain that are shrunken and how well a person can remember words, we can work out which parts of the brain are used for making and storing memories.

“In addition, if medication has not stopped seizures occurring, this helps us to guide neurosurgical treatment for a person’s epilepsy, to avoid damaging the parts of the brain that are needed for memory to work well.”

In the first study of its kind, the UCL team examined 84 people with temporal lobe epilepsy - epilepsy arising from the temporal lobe at the sides of the head - and hippocampal sclerosis, a condition in which part of the brain is scarred, and memory is affected, and 43 healthy people.

The patients were divided into those with left-sided and right-sided hippocampal sclerosis.

High-resolution MRI scans were used to measure the size and shape of different parts of the brain, including the cerebral cortex - the outer layer of the brain responsible for thinking, memory, attention, perception, awareness, and language - and specific areas within the hippocampus, the part of the brain that helps with learning, memory, and spatial navigation.

All the participants underwent tests to assess their verbal memory. The tests were part of the Adult Memory and Information Processing Battery, which measures how well people can remember and recall words.

The research team then compared the memory test scores to the sizes of different brain areas, to see if smaller brain parts were linked to worse memory.

They found that smaller sizes in certain brain areas - such as the prefrontal, temporal and cingulate cortices, and parts of the hippocampus - were linked to worse memory for words in people with epilepsy arising in their temporal lobes.

The research team says their findings are also important for understanding how the brain organizes and remembers words.

Lead author, Dr. Giorgio Fiore added: “This research is important as it helps us to understand how memory may fail and may help guide the designing of neurosurgical operations for epilepsy that will not make memory worse.”