I have just read the recent study done on neurofeedback of mu rhythms in autistic children by UCSD scientist Jaime Pineda. The preceding link is a .pdf file that I uploaded to my stories webpage in case anyone is interested in reading the study in its entirety.
Mu rhythms are a brain wave that is an electrical signal indicative of activity of certain areas of the brain. These areas are located in the frontal lobe and some parts of the parietal lobe. Of interest these brain rhythms are thought to be associated with mirror neuron function. Mirror neurons are a really hot topic in autism brain research right now. One area in which mirror neurons have been found in monkeys is equivalent to Broca's area in humans, which is the area of the brain responsible for expressive speech. It is quite possible that a dysfunction in the mirror neurons in this area could be responsible for the speech delays associated with autism. I have written about this previously
Mirror neurons are a group of neurons that fire, not only when movements are being made but when movements are being observed. In experiments done with monkeys, these brain cells fired both when movement was being done and when movement was being observed by an experimenter, e.g. both when the monkey grasped a peanut and when the monkey observed the experimenter grasping a peanut. In experiments done with autistic children blood would flow to areas of the brain associated with mirror neurons when they were doing movements but not when they were observing movements made. This was not the case in normal controls whose blood flowed to the brain areas both while executing movements and watching movements. Lindsay Oberman (Who at one time was a graduate student in Pineda's lab) did an experiment showing that mu rhythms were suppressed in typical children both when they made hand motions and when they observed the hand motions of others. Autistic children's mu waves were suppressed when making motions but not when watching others' motions.
If it were possible to train an autistic child through feedback, e.g. a tone or a picture that presented itself in a certain way, to suppress the mu rhythms, this could affect the functioning of mirror neurons and thus improve behavior and enable the child to function better. This paper deals with this question.
In this paper, there were actually two different studies done. There were autistic children that were put in both experimental groups and a placebo control group. The experimental subjects were able to learn how to suppress their mu rhythms and the placebo group received a sham training protocol. Prior to this there had been studies of neurofeedback done on autistics but in one the controls were not considered adequate as they lacked a placebo treatment and were aware of test conditions. Other studies have just shown improvement with single subjects and had no controls. This study may be the first randomized group study using experimental groups and control groups to assess the efficacy of neurofeedback in autism. The autistic experimental subjects were able to learn how to suppress their mu rhythms. This was associated with improvement on an autism treatment scale as opposed to the control group as well as greater attention. The ATEC test( autism treatment scale) measured speech language, sociability, sensory cognitive awareness. The experimental group did far better than the placebo group who did not learn how to control their mu rhythms. Imitation behavior was also tested. Slight improvements were seen in both the experimental and control groups but there was no significant difference between the two. So apparently the mu wave suppression training does not affect imitative behaviors which are sometimes a problem with those who have autism.
I believe that this may actually be a promising treatment for at least some autistic people, though probably a lot more experimental work has to be done. One of the problems, as is the case with many autism studies, is that the subjects were for the most part high functioning with overall IQs above 80. In the first study, they were all male subjects. However, in the second study there were 19 subjects, 16 males and 3 females which is fairly close (albeit on the high side)to what the ratio of persons with ASD's is in the general population of autistic persons. In fact, it may actually be lower than the ratio of fairly high functioning autistics, which has been reported to be as high as 10 to 1. Another problem with this study was that there is no way of knowing whether the improvements were due to learning how to suppress the mu rhythms or whether or not some compensatory mechanism was developed. In Mirella Depratto's fMRI mirror neuron study involving autistics, she found that autistic subjects were able to equally imitate facial expressions as well as the typical controls. However, when testing for blood flow to the inferior frontal gyrus the controls would have a high flow of blood oxygen to the inferior frontal gyrus while imitating the facial expressions but the autistics did not have blood flow to these areas. This suggested not only dysfunctions in the inferior frontal gyrus area but that at least some autistics can develop compensatory brain mechanisms in order to imitate facial expressions. Of course, from what I have read, there are some autistics, who have an impaired ability to imitate. The hypothesis for this, of course is that mirror neuron function is impaired. It is not known how long these effects last and Dr. Pineda is continuing research into this line.
I am also interested in TMS as a promising treatment but have not yet done enough research in it to write about it. It is very possible that these could be promising avenues of treatment in at least some persons with ASD's At some point maybe I will write a post about TMS stay tuned!