Musical memory deficits start in auditory cortex

May 1, 2013, CNRS

Congenital amusia is a disorder characterized by impaired musical skills, which can extend to an inability to recognize very familiar tunes. The neural bases of this deficit are now being deciphered. According to a study conducted by researchers from CNRS and Inserm at the Centre de Recherche en Neurosciences de Lyon, amusics exhibit altered processing of musical information in two regions of the brain: the auditory cortex and the frontal cortex, particularly in the right cerebral hemisphere. These alterations seem to be linked to anatomical anomalies in these same cortices. This work, published in May in the journal Brain, adds invaluable information to our understanding of amusia and, more generally, of the "musical brain", in other words the cerebral networks involved in the processing of music.

Congenital amusia, which affects between 2 and 4% of the population, can manifest itself in various ways: by difficulty in hearing a "wrong note", by singing "out of tune" and sometimes by an aversion to music. For some of these individuals, music is like a foreign language or a simple noise. Amusia is not due to any auditory or psychological problem and does not seem to be linked to other neurological disorders. Research on the neural bases of this impairment only began a decade ago with the work of the Canadian Isabelle Peretz.

Two teams from the Centre de Recherche en Neurosciences de Lyon (CNRS / Inserm / Université Claude Bernard Lyon 1) have studied the encoding of musical information and the short-term memorization of notes. According to previous work, amusical individuals experience particular difficulty in hearing the pitch of notes (low or high) and, although they remember sequences of words normally, they have difficulty in memorizing sequences of notes.

In a bid to determine the regions of the brain concerned with these memorization difficulties, the researchers conducted magneto-encephalographs (a technique that allows very weak magnetic fields produced by neural activity to be measured at the surface of the head) on a group of amusics while they were performing a musical task. The task consisted in listening to two tunes separated by a two-second gap. The volunteers were asked to determine whether the tunes were identical or different.

The scientists observed that, when hearing and memorizing notes, amusics exhibited altered sound processing in two regions of the brain: the auditory cortex and the frontal cortex, essentially in the right hemisphere. Compared to non-amusics, their neural activity was delayed and impaired in these specific areas when encoding musical notes. These anomalies occurred 100 milliseconds after the start of a note.

These results agree with an anatomical observation that the researchers have confirmed using MRI: amusical individuals have an excess of grey matter in the inferior frontal cortex, accompanied by a deficit in white matter, one of whose essential constituents is myelin. This surrounds and protects the axons of the neurons, helping nerve signals to propagate rapidly. The researchers also observed anatomical anomalies in the auditory cortex. This data lends weight to the hypothesis according to which amusia could be due to insufficient communication between the and the .

Amusia thus stems from impaired neural processing from the very first steps of sound processing in the auditory nervous system. This work makes it possible to envisage a program to remedy these musical difficulties, by targeting the early steps of the processing of sounds and their .

Explore further: Musical aptitude relates to reading ability

More information: Albouy, P. et al. Impaired pitch perception and memory in congenital amusia: The deficit starts in the auditory cortex, Brain, Volume 136, Issue 5. May 2013. doi:10.1093/brain/awt082

Related Stories

Musical aptitude relates to reading ability

October 17, 2011
Auditory working memory and attention, for example the ability to hear and then remember instructions while completing a task, are a necessary part of musical ability. But musical ability is also related to verbal memory ...

Rewired visual input to sound-processing part of the brain leads to compromised hearing

August 22, 2012
Scientists at Georgia State University have found that the ability to hear is lessened when, as a result of injury, a region of the brain responsible for processing sounds receives both visual and auditory inputs.

Listen up: Abnormality in auditory processing underlies dyslexia

December 21, 2011
People with dyslexia often struggle with the ability to accurately decode and identify what they read. Although disrupted processing of speech sounds has been implicated in the underlying pathology of dyslexia, the basis ...

Recommended for you

New neuron-like cells allow investigation into synthesis of vital cellular components

January 22, 2018
Neuron-like cells created from a readily available cell line have allowed researchers to investigate how the human brain makes a metabolic building block essential for the survival of all living organisms. A team led by researchers ...

Finding unravels nature of cognitive inflexibility in fragile X syndrome

January 22, 2018
Mice with the genetic defect that causes fragile X syndrome (FXS) learn and remember normally, but show an inability to learn new information that contradicts what they initially learned, shows a new study by a team of neuroscientists. ...

Epilepsy linked to brain volume and thickness differences

January 22, 2018
Epilepsy is associated with thickness and volume differences in the grey matter of several brain regions, according to new research led by UCL and the Keck School of Medicine of USC.

Research reveals atomic-level changes in ALS-linked protein

January 18, 2018
For the first time, researchers have described atom-by-atom changes in a family of proteins linked to amyotrophic lateral sclerosis (ALS), a group of brain disorders known as frontotemporal dementia and degenerative diseases ...

Fragile X finding shows normal neurons that interact poorly

January 18, 2018
Neurons in mice afflicted with the genetic defect that causes Fragile X syndrome (FXS) appear similar to those in healthy mice, but these neurons fail to interact normally, resulting in the long-known cognitive impairments, ...

How your brain remembers what you had for dinner last night

January 17, 2018
Confirming earlier computational models, researchers at University of California San Diego and UC San Diego School of Medicine, with colleagues in Arizona and Louisiana, report that episodic memories are encoded in the hippocampus ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.