2004-2008

The University of Maryland describes Gemstone as a "unique multidisciplinary four-year research program for selected undergraduate honors students of all majors." Press release jargon aside, this describes the Gemstone program quite well. Gemstone students come together at the end of their freshman years to form research teams, garner mentors and librarians, and hit the books.^*

In short, our team set out to investigate how humans perceive emotion in music. Our mentor, Dr. Shihab Shamma and one of his lab's doctoral candidates, Nima Mesgarani, graciously allowed us to use some of their research into the brain's recognition of sound (specifically speech) as a basis for our own research. By the end of 2007, we had produced a biological-algorithmic model of the mammalian cochlea and auditory cortex. This algorithm was used to produce a computer program that simulates the brain's reaction to the emotional content of music.

Literature suggests five main categories of emotions illicited by music: happiness, sadness, anger, tenderness, and fear. We chose to use happiness, sadness, and anger for our preliminary run. Our research is extensible to more emotions, though, given more time with which to run surveys.

Below is a representative set of results from one of our classification runs.

We administered a total of 194 surveys, allowing us to apply a happy/sad/angry label to each of our test songs. The chart above, aptly titled a Confusion Matrix, shows that our classify correctly classified 78.5% of the happy songs as happy, 63.5% of the angry songs as angry, and 75% of the sad songs as sad. Most of our runs produced similar numbers -- some higher, some lower. Since randomly applying a label would yield a 33.3% chance of matching, we feel that this 70-75% rate of correctness is relevant.

Here are some appropriate links: our team webpage, UMD's Gemstone page, and a link to our thesis.

^*: Since the groups aren't formed until the last few weeks of the freshman year, "hitting the books" that first summer consists of team building exercises, contemplation of the research question, and solidification of mentor commitments -- really anything but actually hitting the books.