Absolute pitch, or perfect pitch, is the ability to immediately identify or sing a musical tone without a reference pitch. Such an ability is relatively rare in the general population, but is more common among professional musicians; Beethoven, Mozart and Nat King Cole were rumored to have perfect pitch. But what happens in the brain that causes some people to possess this amazing talent? A new study by researchers from the University of Zurich in Switzerland may shed light.
The research team, led by Prof. Lutz Jäncke of the Department of Neuropsychology, discovered that absolute pitch may result from a functional connection between two brain regions: the auditory cortex and the dorsal frontal lobe.
They publish their findings in The Journal of Neuroscience.
Prof. Jäncke and his team say past research has presented two theories as to why some people have absolute pitch.
Firstly, there is the idea that such individuals categorize each musical note during the early stages of sound processing. This means that they are able to process tones in the same way as they process speech sounds and allocate them to specific categories. Under this theory, it is believed that among people with perfect pitch, musical tones are pre-processed in the primary and secondary cortex of their brain.
Other research suggests that individuals with absolute pitch process musical tones later in life, subconsciously associating each musical tone with a memory. This process, according to Prof. Jäncke and his team, is believed to occur mainly in the upper frontal lobe of brain's dorsal frontal cortex.
"Therefore, both theories make completely different statements regarding the moment and the anatomical location of the special processing and there is evidence to support both theories," says Jäncke.
With this in mind, the team set out to gain a better understanding of the neurological mechanisms underlying absolute pitch.
Close working connections found between perception- and memory-related brain regions
The researchers used electroencephalography (EEG) to analyze the brain activity among a sample of musicians, some of whom had absolute pitch.
In particular, they assessed the resting-state connectivity between the left auditory-related cortex (ARC), responsible for perception functions, and the left dorsolateral prefrontal cortex (DLPFC), responsible for late memory functions.
The team found there was a strong synchronization between these two brain regions among participants with absolute pitch, indicating a close working connection during a dormant state. No such connection was found among participants without absolute pitch.
"This coupling enables an especially efficient exchange of information between the auditory cortex and the dorsal frontal cortex in people with absolute pitch, which means that the perception and memory information can be exchanged quickly and efficiently," explains first author Stefan Elmer, adding:
"Our study shows how two brain regions, namely the auditory cortex and the dorsal frontal lobe, work together for absolute pitch. In the process, we combine two essentially conflicting explanatory approaches for the phenomenon."
The team says their findings provide a better understanding of both absolute pitch and efficient auditory processing.
"Auditory perception doesn't only depend on the integrity of the auditory cortex," says Prof. Jäncke, "but also especially on the linking of the auditory cortex with superordinate brain structures that process memory information."
Last month, Medical News Today reported on a study suggesting that learning to play a musical instrument as a child may boost brain development.