It’s noon on a sunny day in San Francisco, and I’m trying to down a double vodka cranberry as fast as I can. Despite reporters’ reputation, drinking is not my typical lunchtime activity. Today I’m visiting neuroscientist Alan Gevins, who has spent the past 40 years developing better ways to analyze the electrical signals emanating from our brains and, in turn, to study how our ability to remember and pay attention changes with different drugs, with the neural glitches of disease, and with the decay of age. In 20 minutes or so, when the alcohol has brought my brain to its peak boozy state, Gevins’s team will measure how it has impacted my neurons as they struggle through a series of memory tests.
Electroencephalography (EEG) is a decades-old technology used to measure electrical activity produced by the brain via electrodes placed on the scalp. In recent years, enhanced computing power and increasingly sophisticated software have allowed scientists to more precisely record and analyze these signals, giving a much greater insight into the meaning behind the brain’s electrical storms. Currently, EEG is used both clinically–to identify the source of seizures in epilepsy patients, for example–and for research, such as to characterize the brain’s rhythmic activity during sleep, relaxation, and concentration.
Gevins, founder of SAM Technology and the San Francisco Brain Research Institute, has developed a system that combines EEG with cognitive testing–computer tests that assess a person’s memory or ability to multitask–to get a more direct measure of the brain’s ability to remember and pay attention. He is now aiming to commercialize the technology, with the eventual goal of using it to more precisely assess cognitive decline and tailor drug prescriptions to minimize cognitive side effects. The technology incorporates both new hardware, to measure electrical activity, and new software, to process those signals.
Previous research by the group suggests that drinking may be more detrimental to our ability to function than previously thought. The brain effects of alcohol remain two to three hours after the behavioral effects have disappeared, even when blood alcohol level is as low as 0.02 percent, about a quarter of the legal limit for driving in most states. “You might be able to summon short bursts of attention and perform well on a short test, but the brain is still abnormal,” says Aaron Ilan, principal neuroscientist at SAM Technology. “You won’t be able to fully focus on a task like driving for several hours.”
The team is now finishing a large study looking at the effects of alcohol, marijuana, caffeine, and diphenhydramine, the active ingredient in Benadryl, on simulated driving, as well as on attention, working memory, and the ability to multitask. The findings should shed light on the cognitive effects of these drugs. While alcohol’s effect on driving is well studied, the same is not true for most prescription drugs.
After I gulp down the last of my vodka, I head back to the testing room at SAM Technology. Earlier that morning, I was fitted with a specially designed black cap dotted with pockets for sensors that detect electrical activity at different spots on the head. The headset is plugged into a small amplifier, which sends its signals wirelessly via Bluetooth to a computer in the testing room. The device captures and processes my brain waves as I play a series of computer games both sober and somewhat drunk. The games are designed to assess working memory–my ability to hold information in my mind for a short time–and my ability to multitask.
An hour later, Gevins and Ilan show me the results of my testing. Their software analyzes a combination of rhythmic brain activity–different frequency rhythms are linked to different cognitive states, such as relaxation or attention–and evoked potentials, electrical signals linked to specific events in the world, like the appearance of a target in a video game. “You were tense; the alcohol relaxed you a lot,” says Gevins, perusing plots of my brain activity on the computer screen.
After drinking, my performance on the games actually improved, probably because I had more practice playing the game. But the EEG data revealed the true impact on my brain function: my brain had to work harder on the more complicated tasks after drinking. And it was slower to react to the targets on the computer screen. (My reaction time was actually faster, probably because my motor system had more practice hitting the mouse. So without the EEG, it would have been impossible to see the effect on the brain.)
Gevins says that one of the most promising venues for the technology will be in guiding prescribing decisions. For example, children with attention deficit hyperactivity disorder (ADHD) are often given stimulant drugs to boost attention, but doctors typically rely on reports from parents and teachers to determine the effectiveness of the medication. “They rarely undergo testing to determine how well the medication is working,” says Gevins. A pilot study from Gevins’s group on children with ADHD suggests that EEG can quickly reveal which children will benefit from Ritalin, a commonly prescribed drug, and when they have reached the optimal dose. He now hopes to partner with a larger company to run clinical trials of the device to determine if it can truly help children with ADHD.
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