When asked about her childhood in the film Alive Inside, a 90-year-old woman with dementia replies, “I’ve forgotten so much, I’m very sorry.” Filmmaker Michael Rossato-Bennett then plays music from her past for her. “That’s Louis Armstrong,” she says, “He’s singing ‘When the Saints Go Marching By’ and it takes me back to my school days.” She then proceeds to recall precise details from her life: that her mother told her not to listen to Louis Armstrong, the date of her birthday, that she worked at Fort Jackson during wartime, and much more.
Alive Inside documents the uncanny power of music to reawaken emotions and lost memories in people with dementia. Rossato-Bennett shadows Dan Cohen, a social worker and founder of the nonprofit Music & Memory, as he brings personalized music on iPods into nursing homes across the country. The transformation in emotion, awareness and memory shown in these elderly patients may leave viewers incredulous, wondering “How is this possible?” A number of researchers have studied this topic, however, and they have some ideas about how music affects the brain—specifically, music that is deeply meaningful to the person.
Music tends to accompany events that arouse emotions or otherwise make strong impressions on us—such as weddings, graduations and even spending good times with friends as a teenager. These kinds of experiences form strong memories, and the music and memories likely become intertwined in our neural networks, according to Julene Johnson, a professor at the University of California, San Francisco’s Institute for Health and Aging. Movements, such as dancing, also often pair with our experience of music, which can facilitate memory formation. Even many years later, hearing the music can evoke memories of these long-past events.  
As Alive Inside shows, music retains this power even for many people with dementia. Researchers note that the brain areas that process and remember music are typically less damaged by dementia than other regions, and they speculate that this sparing may explain the phenomenon.
Another contributing factor might be that elderly people with dementia, especially those in nursing homes, often live in an unfamiliar environment. “It’s possible those long-term memories are still there,” Johnson says, “but people just have a harder time accessing them because there’s not a lot of context in which someone could pull out those memories.” It seems that familiar music might be a good tool to provide context and reconnect with lost memories.
Johnson also notes that music will not have a strong effect on all people with dementia. “This isn’t universal,” she says. “There are some dementias where the recognition of music is impaired.”
In addition to reawakening memories, research and anecdotes have shown that music can soothe agitated patients and thus may avoid the need for antipsychotic drugs to help them calm down.
Despite music’s apparent benefits, few studies have explored its influence on memory recall in people with dementia. “It’s really an untapped area,” Johnson says. Petr Janata, a cognitive neuroscientist in the Center for Mind and Brain at the University of California, Davis, is one researcher investigating the topic of music and memory. He says that although scientists still do not have the answers for why and how music reawakens memories in people with dementia, there is tremendous anecdotal evidence that suggests it does work. “I don’t think we’re there yet with a bulletproof explanation for why this happens,” Janata says, “but I do think this phenomenon is real and it’s just a matter of time before it’s fully borne out by scientific research.”
In the meantime, though, Dan Cohen continues his mission of using music to help patients and their families and caregivers cope with dementia. “We need to use music to engage with people,” Cohen says, “to allow them to express themselves, enjoy themselves and live again.” And he is determined to make this happen all over the country—he has already brought iPods into 640 nursing homes and 45 states, and he aims to establish personalized music as a standard of care in all 50,000 care facilities in the U.S.

Alive Inside is in theaters starting July 18.

Credit: Michael Rossato-Bennett; posted on YouTube by Mahmoud Abdul-Rauf