Apr. 30, 2013 ? 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 (CNRS / Inserm / Universit? Claude Bernard Lyon 1), 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 neuropsychologist Isabelle Peretz.
Two teams from the Centre de Recherche en Neurosciences de Lyon (CNRS / Inserm / Universit? 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 auditory cortex and the frontal cortex.
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 memorization.
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The above story is reprinted from materials provided by Centre national de la recherche scientifique (CNRS).
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Journal Reference:
- P. Albouy, J. Mattout, R. Bouet, E. Maby, G. Sanchez, P.-E. Aguera, S. Daligault, C. Delpuech, O. Bertrand, A. Caclin, B. Tillmann. Impaired pitch perception and memory in congenital amusia: the deficit starts in the auditory cortex. Brain, 2013; 136 (5): 1639 DOI: 10.1093/brain/awt082
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Source: http://feeds.sciencedaily.com/~r/sciencedaily/strange_science/~3/gIAYfMbGmWs/130430131346.htm
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Uber CEO Travis Kalanick said that he hasn’t spoken to investors in a year and half about raising capital, denying reports that the company is raising funding at a $1 billion valuation. Reuters reported that story earlier today, citing one source. We had heard similar rumors over the past few weeks but they weren’t substantiated enough to report. That said, just because Kalanick isn’t speaking to investors about raising money, doesn’t mean that VCs or private equity firms aren’t courting him to take their money. The company, which pioneered on-demand taxi and black cab rides directly from your mobile phone, has raised nearly $50 million to date. The most recent $37 million round was led by Menlo Ventures, which aggressively outbid other competitors on valuation to win the deal. Bill Gurley, a general partner at Benchmark Capital, which came in on Uber’s Series A round, said the company is growing faster than eBay. Uber now lists about 30 different geographic locations around the world where it operates. The company started out with black cabs, then went into environmentally friendly vehicles and then regular cabs. But now it’s making its headway into ride-sharing to compete head-to-head with startups like Zimride’s Lyft and Sidecar, which don’t have the same overhead costs and fees as Uber does. With its original black cab model, Uber partnered with third-party limo and taxi services to provide rides, while Sidecar and Lyft hire regular people with cars who want to earn extra income by driving passengers around. All of these companies, along with Hailo in the U.K. and Europe, and even Chinese taxi apps like DiDi, tie into a global wave of disruption around urban transportation. .@uber hasn’t spoken to a single investor about raising $ since Nov ’11. Any reports to the contrary (i.e. Reuters) are completely false ? travis kalanick (@travisk) April 30, 2013