Can Memorable Words Test for Alzheimer's?

[alice]

Tuesday, June 30
Can Memorable Words Test for Alzheimer's?


A new computer-model reveals fascinating insights into why we remember some words more easily than others. Can NIH researchers further develop it into memory tests for Alzheimer’s and other dementias?



Thousands of words, big and small, are crammed inside our memory banks just waiting to be swiftly withdrawn and strung into sentences. In a recent study of epilepsy patients and healthy volunteers, National Institutes of Health researchers found that our brains may withdraw some common words, like “pig,” “tank,” and “door,” much more often than others, including “cat,” “street,” and “stair.”

By combining memory tests, brain wave recordings, and surveys of billions of words published in books, news articles and internet encyclopedia pages, the researchers not only showed how our brains may recall words but also memories of our past experiences.
Our brains search for memories
“We found that some words are much more memorable than others. Our results support the idea that our memories are wired into neural networks and that our brains search for these memories, just the way search engines track down information on the internet,” said Weizhen (Zane) Xie, Ph.D., a cognitive psychologist and post-doctoral fellow at the NIH’s National Institute of Neurological Disorders and Stroke (NINDS), who led the study published in Nature Human Behaviour. “We hope that these results can be used as a road map to evaluate the health of a person’s memory and brain.”

Dr. Xie and his colleagues first spotted these words when they re-analyzed the results of memory tests taken by 30 epilepsy patients who were part of a clinical trial led by Kareem Zaghloul, M.D., Ph.D., a neurosurgeon and senior investigator at NINDS. Dr. Zaghloul’s team tries to help patients whose seizures cannot be controlled by drugs, otherwise known as intractable epilepsy. During the observation period, patients spend several days at the NIH Clinical Center with surgically implanted electrodes designed to detect changes in brain activity.

“Our goal is to find and eliminate the source of these harmful and debilitating seizures,” said Dr. Zaghloul. “The monitoring period also provides a rare opportunity to record the neural activity that controls other parts of our lives. With the help of these patient volunteers we have been able to uncover some of the blueprints behind our memories.”
The test results
The memory tests were originally designed to assess episodic memories, or the associations – the who, what, where and how details - we make with our past experiences. Alzheimer’s disease and other forms of dementia often destroys the brain’s capacity to make these memories.

Patients were shown pairs of words, such as “hand” and “apple,” from a list of 300 common nouns. A few seconds later they were shown one of the words, for instance “hand,” and asked to remember its pair, “apple.” Dr. Zaghloul’s team had used these tests to study how neural circuits in the brain store and replay memories.

When Dr. Xie and his colleagues re-examined the test results, they found that patients successfully recalled some words more often than others, regardless of the way the words were paired. In fact, of the 300 words used, the top five were on average about seven times more likely to be successfully recalled than the bottom five.