UC Genetics of Absolute Pitch Study

What is absolute pitch?

Absolute pitch, commonly referred to as perfect pitch, is an intriguing cognitive trait involved in music perception and is defined as the ability to identify the pitch of a musical tone without an external reference pitch. To be considered an absolute pitch possessor, an individual must have the ability to identify pitches accurately and instantaneously.

Main objective

The primary goal of this study is to discover the genes that are involved in the development of absolute pitch (perfect pitch). This investigation will allow us to better understand the interplay of genetics and musical training in the development of this cognitive trait. These findings may also be applicable to other traits, such as language ability, and, more broadly, to neurodevelopment.

The goals of this website are to inform the public about the University of California Genetics of Absolute Pitch Study and to recruit individuals to take part in this study. This study is being conducted by the laboratories of Dr. Jane Gitschier at the University of California, San Francisco and Dr. Nelson Freimer at the University of California, Los Angeles. The study has been approved by the UCSF Committee on Human Research. All information collected on individual participants will be kept confidential.

How to participate in the UC Genetics of Absolute Pitch Study

It is easy to participate in our study by filling in a brief survey and taking our pitch-naming test online. Since we are attempting to unravel many factors that could contribute to the development of absolute pitch, both absolute pitch possessors and non-possessors are needed for the study. Everyone's contribution is valuable.

If you indicate in the survey that you are willing to participate in the study, we will need an e-mail address to contact you for follow-up. Some participants may be recontacted for further information about their family history of absolute pitch. We may follow up on the answers to other survey questions as well. Some participants might also be invited to participate further by contributing a DNA sample for our genetic study. This level of participation is, of course, optional.

After filling in the survey, you will be linked to a page informing you how to take the pitch-naming test for absolute pitch. We use this auditory test to objectively assess the pitch naming abilities of our study participants. Our auditory tone test consists of two parts, one test of 40 "pure" tones and one test of 40 piano tones. Since some computer speakers have trouble reproducing a few of the tones, we recommend the use of headphones during the test if you have any.

In each trial, a tone plays for 1 second, followed by a silent interval of 2 seconds. Participants record their guesses within the brief intervals by clicking on a screen keyboard. Tones are given in blocks of ten, allowing participants to rest between blocks if needed. When you are finished, you will be informed of your score and if it exceeds a certain threshold, you meet our study's criteria for being an absolute pitch possessor.

Filling in the survey and taking the pitch-naming test should take less than 20 minutes. Click here to begin.

Our findings to date

Nature vs. nurture

Based the absolute pitch survey and auditory test data we have collected to date, we learned that the majority of individuals with absolute pitch began formal musical training before age 7. This finding supports the hypothesis that early musical training may be necessary for the development of absolute pitch. However, early musical training alone is not sufficient for development of absolute pitch, because many individuals with musical training initiated before age 7 do not possess absolute pitch.

We also observed that absolute pitch aggregates in families, indicating a role for genetic components in its development. Indeed we found that a sibling (with early musical training) of an absolute pitch possessor is about 15 times more likely to possess absolute pitch than is another individual with early musical training but with no family history of absolute pitch.

Together, these observations implicate a genetic predisposition to the development of absolute pitch, which, when coupled with an environmental stimulus such as early musical training, can give rise to the perceptual trait. The development of our pitch-naming test and these initial results were reported in two papers in the American Journal of Human Genetics (1998 and 2000).

These findings encouraged us to develop the project further and to establish an efficient mechanism for recruiting additional subjects and their families into a genetic study. We have now employed our website to recruit thousands of individuals, both absolute pitch and non-absolute pitch possessors, into our study.

Absolute pitch perception as a distinct trait

Based on the results from 2213 subjects who completed our web-based survey and pitch-naming test within a 3-year time span, we learned that absolute pitch (perfect pitch) ability is a discrete perceptual trait, not simply the one end of a continuous "normal" distribution of pitch ability.

The figure below shows a "scatterplot" of the distribution of scores from both the piano tone test (Y-axis) and pure tone test (X-axis) for these subjects. Each dot represents the pair of scores from at least one individual. The area of the dot is proportional to the number of people who scored identically at those piano and pure tone scores.

The scores cluster into two groups. One group is centered at the low range of scores. These scores lie within a box that defines the range of scores expected by random guessing. The other group clusters at the opposite end of the figure, near or at the maximum score of 36 for both the pure and piano tone tests. (Although each test involves 40 tones, we do not score 4 tones, in either test, that lie at the extreme ends of the frequency range.) The vertical line shows the cut-off point for designation of "AP1" in our study. The probability of scoring above this cut-off by chance alone is about one in a trillion!

(Reproduced with permission from Athos et al. 2007. Click to view full article.)

This finding shows that for the population who has entered our study, most people score either very high or very low. A fewer number of subjects score in between these two ranges, and they generally score better on the piano tone test than the pure tone test. We suspect that these individuals have learned to identify some pitches and employ relative pitch to make calculated guesses in pitch-naming.

Changes in pitch perception with age

Absolute pitch possessors sometimes indicate a frustration with their pitch perception as they get older. They sometimes tell us that it goes "off".

The study data corroborate these anecdotal experiences. None of our subjects past the age of 51 identified all of the tones perfectly, unlike their younger counterparts. We discovered that pitch perception tends to go sharp as subjects age. Some subjects name notes consistently a semi-tone sharp by middle-age, while others name tones a full tone sharp as they enter their 60's. We suspect that there is some property in the ear that changes as people age to cause this perceptual shift. Age-related changes are common, such as the need for reading glasses and hearing loss. It is interesting that this change can be observed and quantified only in people who have absolute pitch!

Distortion in pitch perception

By analyzing the vast archive of perceptual data accumulated over the Web, we found something unexpected: absolute pitch possessors tend to err on G# far more than any other tone, an error that occurs only on pure tones. Most often, G# pure tones are misidentified as "A" tones. We hypothesize that this phenomenon reflects the use of A as the universal tuning pitch in Western music. Since the actual frequency of A used in tuning varies widely, from A415 in early music to A446 in some orchestras, we suspect that absolute pitch possessors accommodate a wide range of frequencies in their naming of A. We further speculate that this accommodation is not used in piano tones, since pianos are generally tuned to A440. This phenomenon is reminiscent of a property referred to as "perceptual magnet" in language acquisition.

The above findings on pitch perception have been published in the Proceedings of the National Academies of Science - click here for the article.

Ongoing research

To find genes responsible for the predisposition for developing absolute pitch (perfect pitch), we are dependent on the generous involvement of our subjects. The participation of all of our subjects is voluntary and completely confidential.

First, we are actively recruiting families that have 2 or more members with absolute pitch, as documented by our pitch-naming test. Such families are rare and crucial for ultimately identifying the genetic components responsible for this ability. Upon identification of such families, we invite those individuals and a few of their family members to participate further by donating a small quantity of DNA for our genetic analyses. The molecular analysis of these DNA samples should allow us to identify regions of the human genome that harbor genes for absolute pitch. We have collected DNA in this manner from over 60 families so far, but it is our goal to reach at least 100 families in the next couple of years so that our analysis will be more powerful.

Second, we hypothesize that people from different populations may have different genetic underpinnings for absolute pitch (perfect pitch). This phenomenon is known as "locus heterogeneity". For example, it may be possible that people of Chinese descent have changes in a gene that gives rise to absolute pitch, yet is different from the gene that gives rise to absolute pitch in the Ashkenazi Jewish population. To dissect these population differences, we are now asking about each subject's ethnic origins in our updated survey. (Disclosing this type of ethnicity data is optional for our participants.) We are actively recruiting individuals with absolute pitch from particular populations as a way of dissecting these genetic differences.

Finally, we are recruiting individuals who have had early musical training but do not possess absolute pitch to serve as "controls" for our study. These individuals will enter the study in the same way and may be invited to provide a DNA sample for analysis. The subjects will be matched for ethnicity, age of onset of musical training, and gender with the subjects with absolute pitch. We are looking for DNA features that are consistently different between matched sets of control and absolute pitch-possessing subjects.

In short, there are many ways to participate in our study, both now and in the future. Keep in mind that participation in all stages of our study is optional and kept confidential. To start your journey with us, click below.

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