Report: Alcohol, drugs hurt memory

With final exams just around the corner, work by some Duke researchers on memory and cognition may help students improve their academic performance and understand the science of learning.

Experts say some common student behaviors, like drinking and pulling all-nighters, decrease the ability of some students to learn and recall information. Researchers are also exploring the genetics of memory to understand why some people may have an easier time recalling information than others.

Researchers specializing in brain function stressed the importance of sleep in retaining information learned during the day, and many said alcohol, marijuana and Attention Deficit Hyperactivity Disorder drugs sometimes used as study aids can affect sleep and negatively impact academic performance.

"It is clear that sleep is very important for consolidating what you've learned during the day, both mentally and with motor-based skills such as playing the piano," said Dr. Michael Ehlers, associate professor of neurobiology at the Duke Medical Center.

Binge drinking is known to cause blackouts, or lapses in memory, but excessive alcohol consumption can also disrupt sleep patterns and prevent students from reaching their full academic potential.

"Alcohol is a superb sleep disrupter," said Bill Wilson, associate medical research professor in the Department of Pharmacology and Cancer Biology. Wilson explained that as alcohol levels in the brain decline following a binge, the sedative effect wears off. The brain then becomes hyperexcitable, causing many people to wake up earlier than they normally would.

Although alcohol can impair cognition and memory for a few days following exposure, marijuana has a more prolonged effect, Wilson said.

Alcohol is broken down into inactive molecules that are expelled within a day, but tetrahydrocannabinol, the psychoactive compound found in marijuana smoke, decomposes into active molecules that are stored in fat and continue to influence the smoker days later, he said.

"[ADHD drugs] do promote focus and attention, whether the user has ADHD or not," Wilson said, adding that pilots have used them to stay awake on intercontinental flights.

But Ehlers said that although such drugs offer short-term improvements in attention and recall, they also carry the risk of addiction and can become less effective with repeated use.

Although the molecular basis of learning is not fully understood, some Duke researchers are currently exploring whether genes can cause normal variations in memory among individuals.

"We are targeting a number of cognitive processes like learning, memory and reading comprehension," said Deborah Attix, associate professor of medical psychiatry and director of the clinical neuropsychology service. "If we can identify genes that affect memory performance, we can target pharmacotherapies toward those findings."

Rochelle Schwartz-Bloom, director of undergraduate studies in pharmacology, has advised several students on ways to enhance their ability to learn and recall new information.

"Students learn more from the testing process than they do by studying for the test," she said. "Verbally explaining the answer to someone else helps you articulate it and increases your understanding."

One of the best strategies is for students to get together and test each other on the material prior to an exam, she added.

Schwartz-Bloom also said studies have tended to show higher scores for students taking an exam in the same area where they learned the material than for those who take the exam in other locations. She added that getting an early start on studying is critical to improving performance.

In addition, anxiety, lack of sleep and skipping breakfast prior to an exam have all been shown to decrease scores, Schwartz-Bloom said.