By LIDIA WASOWICZ
SAN FRANCISCO, Jan. 15 (UPI) -- In prying beneath the brain surface of autistic patients, researchers have discovered "cracks" in a system of nerve cells called mirror neurons, which under normal circumstances permit people to see a clear reflection of the actions of others and respond appropriately to them.
Electroencephalograph, or EEG, recordings of 10 individuals with autism revealed that their mirror neurons -- also dubbed "monkey-see, monkey-do" cells -- responded only to their own doings, not to those of others, scientists said.
First identified in the early 1990s in macaque monkeys (hence their nickname), these nerve cells in the premotor cortex -- a movement-controlling brain region -- fire up both when a monkey performs an action and when it sees others imitating it.
Scientists are unable to directly study the counterpart of these nerve cells in people because they cannot be implanted with electrodes for experimental purposes. However, researchers have deduced the presence of a mirror neuron system through indirect brain-imaging measures, such as the EEG.
It now appears these cells have a greater role than previously thought.
A study in the Jan. 6 issue of Nature Neuroscience journal indicates they are involved not only in the execution and observation of movement, but also in higher cognitive processes. These include speaking, imitating and learning from the action of others, by deciphering their intentions and empathizing with their pain.
Because all these abilities come up short in most individuals with autism, scientists have suspected there may be a glitch.
New findings lend substantial support to that theory, providing evidence of a dysfunctional mirror neuron system that may contribute to many impairments, particularly those involving comprehending and responding to the behavior of others, said lead author Mirella Dapretto, assistant professor in residence of psychiatry and biobehavioral sciences at the Semel Institute for Neuroscience and Human Behavior and the David Geffen School of Medicine at the University of California-Los Angeles.
The study sheds new light on the neural basis of autism and may pave the way to early diagnosis and potential therapies, such as biofeedback, the authors said.
The investigators have already experimented with several brain-computer interface techniques that, for example, teach participants in four to six hours how to move a paddle in a computer game simply by imagining the action.
Another possibility might be to use mirrors to "trick" autistic brains into perceiving their own body's reflected movements -- to which they already respond -- as those of another being, scientists said.
Researchers have had some success in using this strategy to treat amputees who feel pain or paralysis in their missing leg or arm. Using a mirror to reflect the healthy limb, they were able to make the brain believe it was the "phantom" appendage fully restored.
It appears a breakdown in this neural network can hinder a child's ability to see and react to not only the movements but also the feelings of others, a skill crucial for social interactions.
This "crack" in the neuron mirror system may be at the root of such hallmarks of autism as difficulty in communicating, interacting, imitating and empathizing, scientists speculate.
"Together with other recent data, our results provide strong support for a mirror neuron theory of autism," Dapretto said. "This is exciting because we finally have an account that can explain ... all core deficits seen in this disorder, including impairments in social communication/interaction, 'theory of mind,' empathy, imitation and even stereotyped/repetitive behaviors."
Using a cutting-edge screening tool called functional magnetic resonance imaging, which gives researchers a front-row view of the brain's inner workings, Dapretto and her team measured the cerebral activity of 10 children with autism and 10 without the disorder. The study participants looked at 80 photographs of faces depicting anger, fear, sadness, happiness or neutrality.
The scientists found a striking contrast between the two groups, even though both were in the same age and IQ range.
Although the autistic children were able to watch and imitate the facial gestures, the pars opercularis of their inferior frontal gyrus -- a brain region near the temple that houses the mirror neurons -- failed to fire up as it was supposed to during the exercise.
In fact, the researchers said they found an inverse relationship: the less the cerebral activity, the greater the child's impairment.
In addition, all was abnormally still in the brain's emotional centers that are involved in understanding others' states of mind, which should have been humming with activity, the scientists said.
The results add validity to the hypothesis that the mirroring mechanism underlies the understanding of and response to the feelings of others -- and that its breakdown can derail an autistic child's capabilities to interact socially, the authors said.
While the investigators worked with high-functioning children on the less-impaired end of the autism spectrum, Dapretto believes the findings can apply to the entire continuum.
As is typical of scientific ventures into the unknown, the study leaves off at a critical juncture that will require further exploration.
"The question of why this system would be impaired is the billion-dollar question," Dapretto said. "If we knew this, we would be in a much better place in terms of developing successful intervention strategies or even a cure for this disorder."
Her best guess puts the blame on both nature and nurture.
"My hunch is that this is very likely to happen ... in development," she said in an e-mail message.
While nobody has any clear-cut evidence of mirror neuron functioning in neonates, the imitation seen in newborn babies can certainly suggest that this system is functional at birth, at least for some type of actions, such as mouth and facial movements that babies had a chance to practice in the womb, she said.
(Note: In this multi-part installment, based on dozens of reports, conferences and interviews, Ped Med is keeping an eye on autism, taking a backward glance at its history and surrounding controversies, facing facts revealed by research and looking forward to treatment enhancements and expansions. Wasowicz is the author of the new book, "Suffer the Child: How the Healthcare System Is Failing Our Future," published by Capital Books.)
Next: Autism at the nature-nurture nexus
--
UPI Consumer Health welcomes comments on this column. E-mail: lwasowicz@upi.com
Copyright 2007 by United Press International. All Rights Reserved.
SAN FRANCISCO, Jan. 15 (UPI) -- In prying beneath the brain surface of autistic patients, researchers have discovered "cracks" in a system of nerve cells called mirror neurons, which under normal circumstances permit people to see a clear reflection of the actions of others and respond appropriately to them.
Electroencephalograph, or EEG, recordings of 10 individuals with autism revealed that their mirror neurons -- also dubbed "monkey-see, monkey-do" cells -- responded only to their own doings, not to those of others, scientists said.
First identified in the early 1990s in macaque monkeys (hence their nickname), these nerve cells in the premotor cortex -- a movement-controlling brain region -- fire up both when a monkey performs an action and when it sees others imitating it.
Scientists are unable to directly study the counterpart of these nerve cells in people because they cannot be implanted with electrodes for experimental purposes. However, researchers have deduced the presence of a mirror neuron system through indirect brain-imaging measures, such as the EEG.
It now appears these cells have a greater role than previously thought.
A study in the Jan. 6 issue of Nature Neuroscience journal indicates they are involved not only in the execution and observation of movement, but also in higher cognitive processes. These include speaking, imitating and learning from the action of others, by deciphering their intentions and empathizing with their pain.
Because all these abilities come up short in most individuals with autism, scientists have suspected there may be a glitch.
New findings lend substantial support to that theory, providing evidence of a dysfunctional mirror neuron system that may contribute to many impairments, particularly those involving comprehending and responding to the behavior of others, said lead author Mirella Dapretto, assistant professor in residence of psychiatry and biobehavioral sciences at the Semel Institute for Neuroscience and Human Behavior and the David Geffen School of Medicine at the University of California-Los Angeles.
The study sheds new light on the neural basis of autism and may pave the way to early diagnosis and potential therapies, such as biofeedback, the authors said.
The investigators have already experimented with several brain-computer interface techniques that, for example, teach participants in four to six hours how to move a paddle in a computer game simply by imagining the action.
Another possibility might be to use mirrors to "trick" autistic brains into perceiving their own body's reflected movements -- to which they already respond -- as those of another being, scientists said.
Researchers have had some success in using this strategy to treat amputees who feel pain or paralysis in their missing leg or arm. Using a mirror to reflect the healthy limb, they were able to make the brain believe it was the "phantom" appendage fully restored.
It appears a breakdown in this neural network can hinder a child's ability to see and react to not only the movements but also the feelings of others, a skill crucial for social interactions.
This "crack" in the neuron mirror system may be at the root of such hallmarks of autism as difficulty in communicating, interacting, imitating and empathizing, scientists speculate.
"Together with other recent data, our results provide strong support for a mirror neuron theory of autism," Dapretto said. "This is exciting because we finally have an account that can explain ... all core deficits seen in this disorder, including impairments in social communication/interaction, 'theory of mind,' empathy, imitation and even stereotyped/repetitive behaviors."
Using a cutting-edge screening tool called functional magnetic resonance imaging, which gives researchers a front-row view of the brain's inner workings, Dapretto and her team measured the cerebral activity of 10 children with autism and 10 without the disorder. The study participants looked at 80 photographs of faces depicting anger, fear, sadness, happiness or neutrality.
The scientists found a striking contrast between the two groups, even though both were in the same age and IQ range.
Although the autistic children were able to watch and imitate the facial gestures, the pars opercularis of their inferior frontal gyrus -- a brain region near the temple that houses the mirror neurons -- failed to fire up as it was supposed to during the exercise.
In fact, the researchers said they found an inverse relationship: the less the cerebral activity, the greater the child's impairment.
In addition, all was abnormally still in the brain's emotional centers that are involved in understanding others' states of mind, which should have been humming with activity, the scientists said.
The results add validity to the hypothesis that the mirroring mechanism underlies the understanding of and response to the feelings of others -- and that its breakdown can derail an autistic child's capabilities to interact socially, the authors said.
While the investigators worked with high-functioning children on the less-impaired end of the autism spectrum, Dapretto believes the findings can apply to the entire continuum.
As is typical of scientific ventures into the unknown, the study leaves off at a critical juncture that will require further exploration.
"The question of why this system would be impaired is the billion-dollar question," Dapretto said. "If we knew this, we would be in a much better place in terms of developing successful intervention strategies or even a cure for this disorder."
Her best guess puts the blame on both nature and nurture.
"My hunch is that this is very likely to happen ... in development," she said in an e-mail message.
While nobody has any clear-cut evidence of mirror neuron functioning in neonates, the imitation seen in newborn babies can certainly suggest that this system is functional at birth, at least for some type of actions, such as mouth and facial movements that babies had a chance to practice in the womb, she said.
(Note: In this multi-part installment, based on dozens of reports, conferences and interviews, Ped Med is keeping an eye on autism, taking a backward glance at its history and surrounding controversies, facing facts revealed by research and looking forward to treatment enhancements and expansions. Wasowicz is the author of the new book, "Suffer the Child: How the Healthcare System Is Failing Our Future," published by Capital Books.)
Next: Autism at the nature-nurture nexus
--
UPI Consumer Health welcomes comments on this column. E-mail: lwasowicz@upi.com
Copyright 2007 by United Press International. All Rights Reserved.
