[autismo-biologia] [Autism] research: mirror neuron system functions normally in ASD (fwd)

Pier Luigi Fortini fortini a fe.infn.it
Gio 20 Maggio 2010 15:00:44 CEST


vi allego un lavoro da cui sembra che i mirrors, se pure esistono, non 
abbiano effetto alcuno sull' autismo.

Pierluigi Fortini

---------- Forwarded message ----------
Date: Wed, 19 May 2010 07:35:40 -0400
From: "Gail Schrimmer, PhD" <drgs a comcast.net>
Reply-To: International general autism support and information.
     <autism a lists.apana.org>
To: International general autism support and information.
     <autism a lists.apana.org>
Subject: [Autism] research: mirror neuron system functions normally in ASD

Title:  Researchers find mirror neuron system functions normally in
individuals with autism

This news release can be found at this web address < http://bit.ly/bwQ3fs >

A team of neuroscientists has found that the mirror neuron system, which is
thought to play a central role in social communications, responds normally
in individuals with autism. Their findings, reported in the journal Neuron,
counter theories suggesting that a mirror system dysfunction causes the
social difficulties exhibited by individuals with autism.

The mirror neuron system, the focal point of the Neuron study, is composed
of two brain areas, which have a unique characteristic—they are active both
when we execute movements (e.g. grasping a cup of coffee) and when we
passively observe other people executing those same movements. It has been
known for many years that these brain areas are important for proper motor
control because trauma to these areas causes movement deficits. Yet it has
only recently been discovered that these brain areas respond when passively
observing others. It has been proposed that this activity represents a
process of “movement simulation” that enables us to understand the meanings
and the goals of movements we observe.

For the simulation process to work properly, it is imperative that we
simulate the exact same movement we are observing. This means that neurons
within our mirror system must recognize movements and respond with a unique,
movement-selective, response to each (or else we’ll confuse different
movements and attribute improper goals to the person we’re observing).

Because individuals with autism have difficulty communicating socially and
understanding the emotions and intentions of others, it has been
hypothesized that they may have a dysfunction in their mirror neuron system.
This hypothesis has received a tremendous amount of attention in both the
popular and scientific literatures following a number of studies that
reported weak mirror neuron system responses in individuals with autism. The
issue of movement-selectivity, however, had not been addressed in these
studies.

To further test this influential theory, the researchers asked individuals
with autism and a control group to observe and execute different hand
movements while being scanned with functional magnetic resonance imaging
(fMRI). The fMRI measurements allowed the researchers to infer the strength
of neural responses in mirror system areas of each group during movement
observation and execution. Their results showed that mirror system areas of
individuals with autism not only responded strongly during movement
observation, but did so in a movement-selective manner such that different
movements exhibited unique neural responses. The mirror system responses of
individuals with autism were, therefore, equivalent to those commonly
reported (and observed here) for controls.

These results, they conclude, argue strongly against the “dysfunctional
mirror system hypothesis of autism” because they show that mirror system
areas respond normally in individuals with autism. The authors, therefore,
suggest that it may be more productive to re-focus autism research in more
promising directions.

The study’s co-authors are: Ilan Dinstein, a former graduate student at New
York University and now a postdoctoral fellow at the Weizmann Institute in
Israel; Cibu Thomas, Kate Humphreys, and Marlene Behrmann from Carnegie
Mellon University; Nancy Minshew from the University of Pittsburgh; and
David Heeger from New York University.

The study was supported by grants from the National Institutes of Health,
Cure Autism Now, and the Pennsylvania Department of Health.


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