Of Mirror Neurons, Fever, and Autonomic Storms
October 16, 2006 by Kristina Chew, PhD
Filed under Health
The November 2006 issue of Scientific American contains an article on mirror neurons, a newly discovered class of brain cells, and autism—-and the article goes beyond a discussion of these to consider autistic children’s difficulty understanding metaphors, what happens when an autistic child gets a fever, and why self-stimulatory behaviors such as repetitive motion and head-banging might occur. According to the article by Vilayanur S. Ramachandran and Lindsay M. Oberman of the Center for Brain and Cognition at the University of California, San Diego in their article Broken Mirrors: A Theory of Autism:
Because these neurons appeared to be involved in abilities such as empathy and the perception of another individual’s intentions, it seemed logical to hypothesize that a dysfunction of the mirror neuron system could result in some of the symptoms of autism. …
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If the mirror neuron system is indeed involved in the interpretation of complex intentions, then a breakdown of this neural circuitry could explain the most striking deficit in people with autism, their lack of social skills. The other cardinal signs of the disorder–absence of empathy, language deficits, poor imitation, and so on–are also the kinds of things you would expect to see if mirror neurons were dysfunctional.
Dr. Ramachandran’s research team looked at the EEGs of autistic children (first in those termed “high-functioning,” that is, “without severe cognitive impairments”). They focused on one component of the EEG, the mu-wave, which “is blocked anytime a person makes a voluntary muscle movement, such as opening and closing one’s hands. Interestingly, this component is also blocked when a person watches someone else perform the same action.”
The EEG showed that the child had an observable mu wave that was suppressed when he made a simple, voluntary movement, just as in normal children. But when the child watched someone else perform the action, the suppression did not occur. We concluded that the child’s motor command system was intact but that his mirror neuron system was deficient.
The EEG’s of ten more “high-functioning” autistic children and ten non-autistic children of the samge age were studied, with similar results.
What I find especially interesting about Dr. Ramachandran’s research are some points concerning autistic persons’ understanding of language and also about certain behaviors such as head-banging made in the latter part of the Scientific American article. In particular, the article notes that a part of the brain called the angular gyrus—”which sits at the crossroads of the brain’s vision, hearing and touch centers”—is involved in “cross-domain mapping,” which enables a person to extract abstract properties from concrete shapes and sounds—-and, further, that nerve cells with properties like those of mirror neurons have been identified in this part of the brain.
- Regarding the difficulty that autistic children have to interpret metaphors and figurative language, the researchers noted that “cross-domain mapping may have originally developed to aid primates in complex motor tasks such as grasping tree branches (which requires the rapid assimilation of visual, auditory and touch information) but eventually evolved into an ability to create metaphors. Mirror neurons allowed humans to reach for the stars, instead of mere peanuts.”
Not all “symptoms” of autism can be explained by the mirror neuron hypothesis, though, including sensory needs such as rocking and hypersensitivity. The article notes that Dr. Ramachandran’s researchers have developed the “salience landscape theory” (in conjunction with, among others, Portia Iversen of CAN).
Our group decided to explore the possibility that children with autism have a distorted salience landscape, perhaps because of altered connections between the cortical areas that process sensory input and the amygdala or between the limbic structures and the frontal lobes that regulate the resulting behavior. As a result of these abnormal connections, any trivial event or object could set off an extreme emotional response–an autonomic storm [my emphasis]–in the child’s mind…..
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Investigators have found that nearly one third of children with autism have had temporal lobe epilepsy in infancy, and the proportion may be much higher given that many epileptic seizures go undetected. Caused by repeated random volleys of nerve impulses traversing the limbic system, these seizures could eventually scramble the connections between the visual cortex and the amygdala, indiscriminately enhancing some links and diminishing others.
Repetive motions, head-banging, and other self-stimulatory behaviors might (the researches hypothesize) “damp the child’s autonomic storms.” That is, an autistic child engages in such repetitive motions such as flapping or rapid pacing in the midst of an “autonomic storm” in which nerve impulses are occurring in unpredictable confusion in their systems. The researchers also note, somewhat parenthetically:
Our findings on autonomic responses may help explain the old clinical observation that high fever sometimes temporarily alleviates the symptoms of autism. The autonomic nervous system is involved in controlling body temperature; because fever and the emotional upheavals of autism appear to be regulated by the same neural pathways, perhaps the former can mitigate the latter.
Charlie’s speech has sometimes been shockingly clear when he has had a fever. Over the past year, we have tried hard to understand why he head-banged (or used to, as he has not been doing this as much) and have been learning that it is sometimes for attention and communication, and sometimes for self-stimulatory reasons. Charlie often paces–running up and down the driveway of our house or up and down a room before jumping on the bed—-and he often seems to do this before becoming calmer, or to “work off” something more than energy.
The Scientific American article notes that it is making “conjectures” regarding mirror neurons and the “salience landscape theory.” I hope that this research can continue to provide important clues to understand the different wiring of Charlie’s brain—-and to learn from it.
This is interesting. One of the physiological changes that accompanies fever is an increase in NO levels through expression of inducible nitric oxide synthase.
http://erj.ersjournals.com/cgi/content/full/21/4/594
Interesting that fever sometimes reduces symptoms of ASDs.
We are independent researchers studying mirror neurons and have recently come to conclusion that the results of the experiments conducted by Iacoboni et al (2005) do not support the notion that mirror neurons code intention. If you are interested, we would like send you work entitled “The Link Between Mirror Neurons and Intention (Iacoboni et al 2005) Is Subject To Further Investigation.” Abstract attached.
Sincerely,
Ludmila Vucolova, USA
vucolova@gmail.com
Peter Boroditch, Russia
magelan55@mail.ru
ABSTRACT
This work will analyze the findings of Iacoboni et al., 2005 wherein is stated “the human mirror neuron system does not simply provide an action recognition mechanism, but also constitutes a neural system for coding the intentions of others” and will suggest that the findings are not supported by the results of the experiments.
The analysis of Iacoboni’s findings demonstrates that the alleged greater activity in mirror neuron areas in the inferior frontal cortex in the Intention cleaning condition did not show sufficient additional activity to support the principal finding.
The analysis demonstrates that alleged greater activity in mirror neuron areas in the inferior frontal cortex in the Intention drinking condition is not valid since the comparison between Action, Intention drinking and Intention cleaning conditions was not based on the premises of the hypothetical model (identical grasping actions), thus, leading to an improper reading of the data and interpretation of the findings.
The high response in the Intention drinking condition versus Action and Intention cleaning is attributed instead to differences in the types of grasping actions, implemented by Iacoboni and observed by participants. These differences affect the level of mirror neuron response. The high level reported in the Intention drinking is due to the instantaneous recognition of two actions, “grasping” and “bringing to the mouth.” These are found to be two consecutive and adjoining links within the drinking action. The lack of additional response in Intention cleaning is due to the recognition of only the grasping action by viewing the Intention cleaning clip. Consequently, the need to resort to the understanding of intention to account for the high response (in the Intention drinking condition) can be eliminated.
my son has been diagnosed with autonomic storms . he is 15 years old and has cerebal palsey . i would like to know of a neuroligest that knows of this . it seems when he has b.m is when he gets really bad and when he doesnt have a b.m he is relaxed we are trying chlonidine right now but doesnt seem to be working hopefully are neurologist is on the right track my son needs all the help he can get he has a baclofyn pump and he has a shunt for hydrocefolis if anyone has a idea what to do please let me know we are kind of desperate