What is it about music that makes it stick with us? That we remember songs and the experiences associated with those songs so vividly...even years later?

Music therapists who work with clients living with Alzheimer's have countless stories all with the same plot. In these stories, there's a client who is suffering from Alzheimer's. This client is in the later stages of the disease process--perhaps she can't talk anymore or even recognize her spouse of 50-odd years. But once that music therapist starts singing a song she loved as a teenager? That client starts singing right along (and, in other variations, dances with that spouse à la James Garner and Gena Rowlands in the movie "The Notebook").

Last year a study came out that outlined where in our brain that connection happens. What structure is responsible for this powerful music-memory association?

The answer: The medial prefrontal cortex (MPFC).

The MPFC lies right behind our forehead and is thought to be responsible for self-referential processes, including our ability to integrate sensory information--such as music--with autobiographical information.

In his study, published in 2009 in Cerebral Cortex, Petr Janata, a researcher at the University of California-Davis, had college-age students, while hooked up to an fMRI machine, listen to 30 second snippets of songs popular when they were 8-18 years old. After listening to each excerpt, the participant answered questions about the song (e.g. was it familiar to you? what it enjoyable?) as well as questions about the content and vividness of memories that were associated with that song.

By comparing their answers with their brain activity while listening to the excerpt, Janata found that the dorsal regions of the MPFC seemed to be the area responsible for associating music and memories, especially when those memories were emotionally-salient.

So why, then, does this reaction happen when one's brain has been ravaged by Alzheimer's disease? According to Janata, this part of the brain is one of the last regions to atrophy. This is why autobiographical information can remain so strong in a person...and music provides an easy way to access that information.

So what does this mean if you have a loved one who has dementia? Your best option is to connect with a board-certified music therapist, see if s/he can work with your loved one.