Former Grateful Dead Drummer's Brain Activity Recorded While He Plays Mickey Hart gets his head examined as he plays the drums.

Sept. 10, 2013 -- When Mickey Hart played drums for the Grateful Dead, he said he became intimately familiar with several mind-altering substances.

Now, as he approaches his 70th birthday, he's still preoccupied with his mind but has put it in the hands of neuroscientist Adam Gazzaley at the University of California, San Francisco.

Gazzaley was first introduced to Hart when he was preparing a talk for an AARP conference on why older people should care about brain rhythms. "Recently, [neuroscientists] have grown an appreciation for these rhythms, since they're associated with different aspects of perception, cognition and attention," Gazzaley told ABC News.

Hart also became interested with the brain's rhythms, especially after his grandmother was diagnosed with advanced Alzheimer's disease.

"She hadn't spoken in over a year. I played a drum for her, and she spoke my name," said Hart, speaking with ABC News' reporter Jonathan Bloom in San Francisco. "She started to become connected again -- to become verbal."

The rhythm of Hart's drum isn't the same as the rhythm of his brain, but there is a connection between the two. Gazzaley explained that different sections of the brain activate and deactivate at the same time, resulting in a rhythmic pulse of activity throughout a brain region.

But when we age, that rhythm starts to shift. "The rhythmic connection between different brain areas can change, or the frequency of the rhythm itself could change."

Using a customized electroencephalogram, or EEG, cap, Gazzaley can measure the rhythm of Hart's brain as he plays the drums. The duo's debut at last year's AARP conference shows some of Hart's brain rhythms. Some creative liberties were taken in presenting the data to the audience.

"We made some artistic decisions on how best to present Mickey's brain rhythms," said Gazzaley. "But the brain is so vastly complicated that it would be chaos if we tried to display everything at once."

"I played a drum for her and she spoke my name."

Gazzaley and Hart have chosen not to focus on music but have developed an iPad game to help players better understand and manipulate rhythm. While some of the initial claims about how music can improve brain function were later discredited (Baby Mozart, anyone?), Robert Zatorre, a professor of neuroscience at the Montreal Neurological Institute, said that music did offer some tangible brain benefits.

"Training in music results in a brain that is much more precise at recognizing small differences in time," he said. "It also enhances the ability to both perceive and produce movements sensitive to timing, like speech."

Zatorre is one of a handful of researchers around the world that study how music (melody and all) influences the brain. He cautions casual readers not to take this particular collaboration as gospel, although he said that Gazzaley was a great scientist and that his work was exciting.

"It's conceivable that enhancing someone's sense of timing might have good repercussions for lots of different aspects of cognition," he said. "But does that mean we found a cure for Alzheimer's? I don't think so."

Gazzaley agreed that people should not blow his AARP presentation out of proportion. "That was as much an artistic expression as anything else," he said. But the core concepts are there, he said, and he planned to expand on them. "We're working with nVidia to improve real time EEG and use it as a research tool."

While Gazzaley is looking on how to rescue an aging brain from memory loss and inattentiveness, Ron Petersen, the director of the Mayo Clinic's Alzheimer's Research Center, sees rhythm and music as a tool for patients when reversing the brain's wear and tear isn't possible.

"If you show 20-, 30- even 40-year old photographs to people with Alzheimer's disease, they can have a fluent conversation about those memories," he said. "Music could be employed in the same fashion and put their minds at ease."

In addition, he said that the mechanisms behind tapping old memories and creating new ones were inherently different, though exactly how is still a subject for research.

"The cap might shed some light on what regions are brought into play," said Petersen. "Different areas will light up in Mickey if he's done a song a million times, or if he's just jamming."