Neurofeedback is a popular albeit controversial intervention used in the
treatment of ADHD. Scientists have long known that different types of brainwave
activity in the brain are associated with either a focused and attentive
state or a drowsy/day-dreaming state. In neurofeedback treatment, a
person is able to view these brainwaves on a computer screen as they occur.
By teaching a person to produce brainwave patterns associated with an alert
and focused state, and having them practice this skill for many hours of
training, neurofeedback practitioners contend that individuals with ADHD
can learn to maintain this state. As a result, the symptoms of ADHD
will diminish. Many scientists do not believe that such claims have been
sufficiently documented, however.
A typical clinical session of neurofeedback training for a child with ADHD
involves pasting electrodes (sensors that pick up the electrical activity
of the brain) to the head with conductive gel. Wires from these electrodes
are connected to a device that amplifies the small signal obtained from the
electrodes. The child sits in a comfortable chair and watches a computer monitor.
The monitor displays a picture such as a moving graph that indicates the
degree to which the child is producing the desired pattern of brainwave activity.
The goal is for the child to learn to produce the type of brainwave activity
that is associated with a focused and attentive state.
Over the course of numerous training sessions it may gradually become easier
for the child to achieve this state and to maintain it for longer periods
of time. Proponents of neurofeedback often describe this training as an exercise
program for the brain, and training continues until the client demonstrates
the ability to consistently achieve and maintain a pattern of EEG activity
indicative of a relaxed and attentive state. This typically requires 40-60
By the conclusion of treatment, neurofeedback advocates believe that increases
in attention and reductions in impulsivity that are evident during training
will transfer to important areas of the child's life - e.g. home and school
- and there are several published studies (see below) that are consistent
with this position. Critics of neurofeedback, however, do not believe
there is credible evidence to indicate that such transfer occurs.
Prior Neurofeedback Research Reviewed in Attention Research Update
In prior issues of Attention Research Update I have reviewed several neurofeedback
studies that highlight the promise of this approach for helping individuals
with ADHD. In the first study (Monastra
et al., 2001), 101 children and adolescents with AD/HD received multimodal
treatment that included stimulant medication, behavioral therapy, and school
consultation services. Fifty-one of these participants also received neurofeedback
because their parent(s) decided to include it in their child's overall treatment
plan. Participants in each group (i.e. multimodal treatment vs. multimodal
treatment + neurofeedback) did not differ in the severity of symptoms before
treatment began, and the treatment provided differed only by whether it included
Twelve months later, participants whose treatment included neurofeedback
showed greater improvement according to parent and teacher behavior ratings,
and no longer demonstrated the brainwave patterns that are indicative of ADHD.
These gains remained evident a week after medication was discontinued and
suggest that adding neurofeedback to a multimodal treatment program was associated
with important benefits. You can find a comprehensive review of this
study at http://www.helpforadd.com/2003/january.htm
In a second study
(Fuchs et al., 2003), parents of 34 children with AD/HD between the ages
of 8 and 12 chose either stimulant medication or neurofeedback treatment for
their child. The majority - the parents of 22 children -- opted for
neurofeedback treatment. After 3 months, children in both groups showed
significant and comparable reductions in ADHD symptoms according to parents
and teachers. Laboratory tests of attention also showed equivalent improvement.
A comprehensive review of this study is available at http://www.helpforadd.com/2003/april.htm
Clearly, children in both studies who received neurofeedback appeared to
benefit from this treatment. Critics of these studies would correctly point
out, however, that neither employed random assignment. The absence of
random assignment makes it impossible to rule out other factors the groups
may have differed on - besides whether they received neurofeedback - as an
explanation for the results obtained. This limitation is found in virtually
all studies of neurofeedback.
Another limitation is the failure to control for the substantial extra
therapist attention provided to children who received neurofeedback treatment.
It is possible that this extra attention - and not neurofeedback training
per se - is what accounts for children's improvement. Although
this seems unlikely given the intractability of ADHD symptoms to adult attention
and support alone, it cannot be conclusively ruled out.
New Study of Neurofeedback for Treating
A recently published study addresses one of these important concerns, i.e.,
the absence of random assignment, and also provides direct evidence of changes
in brain activity for children receiving neurofeedback (Levesque, J., Beauregard,
M., & Mensour, B. 2006. Effect of neurofeedback training on the neural
substrates of selective attention in children with AD/HD: A functional magnetic
resonance imaging study. Neuroscience Letters, 394, 216-221.)
Participants were 20 8-12-year-old children (4 girls and 16 boys) meeting
DSM-IV criteria for ADHD; children who were also diagnosed with learning disabilities
or a psychiatric diagnosis in addition to ADHD were excluded. Fifteen
children were randomly assigned to receive 40 hour-long sessions of neurofeedback
training conducted over a 13-week period. More children were assigned
to the treatment group so that a greater number of treated subjects could
participate in the fMRI procedure described below.
Consistent with what is known about EEG (i.e., brainwave) activity in individuals
with ADHD, training focused on reducing the production of lower frequency
theta waves and increasing the production of higher frequency beta waves
that are associated with a more focused and attentive state. Control
children received no active intervention, nor did they receive comparable
amounts of adult attention. Although children in both groups had received
stimulant medication treatment prior to the study, no child received medication
during the study.
Both before and after neurofeedback training, the following measures were
collected on participants in the treatment and control groups:
1) Parent ratings of ADHD symptoms;
2) Digit Span - This test requires children to repeat in correct order
strings of digits that are read to them. The strings get increasingly
longer until the child fails 2 trials in succession. After failing
2 successive trials, the test is repeated with children required to repeat
the digits back in reverse order. Performance on this test depends
on both attention and working memory skills.
3) Continuous Performance Test - This is a computerized test of sustained
attention and the ability to inhibit impulsive responding. In this test,
the child is presented with a series of auditory and visual stimuli via computer
and must either respond or inhibit responding by pressing particular keys
according to the stimulus that is presented. To perfom well on this
task, children need to maintain careful attention to the computer monitor
and refrain from pressing keys impulsively when the wrong stimulus is presented.
This measure is widely used in the evaluation of attention difficulties.
4) Counting Stroop Task - This is a complex experimental task that involves
both selective attention and the ability to inhibit a well-learned response.
In this task, children are told that they will see sets of 1-4 identical words
appear on the computer screen. Their job is to indicate how many words
were presented by pressing a button the appropriate number of times.
On some trials, the words consisted of names of common animals, e.g., dog,
cat, bird, etc. For example, the word "cat" would appear 3 times and
the child would need to press the button 3 times. If the word appeared
only once, the child would press the button once. During these "neutral"
trials, the task was thus relatively easy.
On other trials, however, referred to as "interference" trials, number
words, e.g., "one", "two", "three", appeared on the screen. For example,
the word "one" might be written 3 times, requiring the child to button press
3 times. This is a more difficult task because the content of the word
- the number one - conflicts with the number of button presses the child must
make. Prior research has demonstrated that different brain areas are
activated during these different types of trials. (Note - This is a
variant of the more familiar color Stroop task, in which it is harder to
name the color that words are printed in when the ink color is different from
the word itself, e.g., when color words are written in green ink, it takes
longer to say the ink is gren when the word written is "red" than when the
word written is "green". You can try this for youself at http://faculty.washington.edu/chudler/words.html
All children completed the Counting Stroop Task before and after those
in the experimental group received neurofeedback treatment. A total
of 120 "neutral" and "interference" trials were conducted during each testing
session and children's score was the number of trials they answered correctly.
An especially important feature of this study is that children received
fMRI scans as while completing the Counting Stroop Task. fMRI is a technique
for determining which parts of the brain are activated as individuals perform
certain tasks by "imaging" the increased blood flow to the activated areas
of the brain.
The inclusion of fMRI scans during the Counting Stroop Task enabled the
researchers to examine results on this task in 2 ways. First, they
could determine whether treated children performed better after treatment
compared to the control group. And, second, they could determine via
fMRI data whether patterns of brain activation during the task changed in
neurofeedback-treated children. Because neurofeedback is intended to
change the underlying pattern of brain activity, demonstrating such a change
is an important step in documenting the efficacy of this approach.
Results indicated clear improvements for children receiving neurofeedback
treatment. Specifically, the authors reported the following:
1) For treated children, parent ratings of inattentive ADHD symptoms declined
significantly - into the normal range - while those of control children remained
2) For treated children, parent ratings of hyperactive/impulsive ADHD symptoms
declined significantly - although not quite into the normal range - while
those of control children showed a modest increase.
3) On the Digit Span test, scores for treated children increased significantly
from time 1 to time 2; for control children, no significant increase was found.
4) On the Continuous Performance Test, scores for treated children increased
significantly from time 1 to time 2; for control children, no significant
increase was found.
5) On the Counting Stroop Task, treated children performed significantly
better on both neutral and interference trials at time 2 compared to time
1; for control children, no increase in the accuracy of their performance
6) fMRI results showed no difference in patterns of brain activation between
treated and control children at time 1. At time 2, however, treated
children showed a different pattern of brain activation during the interference
trials, i.e., those that required more complex cognitive processing.
The brain regions showing increased activation were those believed to play
important roles in selective attention and the suppression of inappropriate
SUMMARY and IMPLICATIONS
This study provides important new evidence to support the use of neurofeedback
as a treatment for ADHD. Advantages over several previously published
neurofeedback studies are that participants were randomly assigned to the
treatment vs. control conditions and the inclusion of fMRI scans to document
that neurofeedback treatment was associated with actual changes in brain activity
during a complex cogntive task.
As with previously published studies, treatment was associated with a significant
reduction in parent ratings of their child's ADHD symptoms. Because
parents were not blind to condition, however, one can argue that this finding
is confounded by parents' knowledge of whether their child received treatment.
In other words, parents may have reported their child symptoms improved simply
because they expected this would happen and not because objective changes
Improvements for treated children in Digit Span and the Continuous Performance
test - both considered to be objective assessments of attention and other
cognitive skills - are not subject to this same criticsm, however, and thus
provide a stronger basis for suggesting the neurofeedback treatment was helpful.
Most compelling of all, however, is the finding that neurofeedback treatment
was associated with changes in brain activation detected by fMRI scans during
the Counting Stoop Task. Proponents of neurofeedback treatment have
long suggested that it produces enduring changes in brain functioning, and
that it is these changes that cause ADHD symptoms to diminish. Results from
this study provide important initial evidence consistent with this hypothesis,
although the absence of any long-term follow up makes it impossible to know
whether the changes detected were transient or enduring.
While these results are encouraging, a balanced review of any study requires
a discussion of it's limitations, and there are several to note. First,
the sample size is relatively small and replicating the findings with a larger
sample would be important.
Another limitation of the sample is that children with learning disabilities
and diagnoses in addition to ADHD were excluded. Because many children
with ADHD have one or more co-occurring conditions which can complicate treatment,
it is not clear whether the results obtained would generalize to a broader
and more representative sample of children with ADHD.
Third, the only behavior measure obtained was from parents who were not
blind to treatment condition. Because improving children's behavioral
and academic functioning in school is an especially important goal of ADHD
treatment, the absence of such information from teachers is problematic;
it should not be assumed that such changes in the classroom would also be
Finally, as the authors note, the control participants did not receive
any attention training intervention whatsoever. Thus, although it is
tempting to conclude that specific training in changing brainwave activity
was responsible for the treatment effects - including changes that were found
in the fMRI scans - this conclusion cannot be made with certainty.
For example, training a different pattern of EEG activity using neurofeedback,
or an attention training intervention in which no direct feedback on EEG activity
was provided, may have yielded similar results. One could even argue
that the greater contact with researchers received by children in the treatment
group - 40 hours vs. 0 for those in the control group - is what accounted
for the treatment gains and that neurofeedback itself had nothing to do with
Although I do not find this to be a likely explanation, the study design
does not enable this possibility to conclusively ruled out. In an ideal
design, control children would go through a neurofeedback procedure that appeared
identical to what treated children received, only the training would provide
"sham" feedback that was not linked to their actual EEG activity. If
group differences were found with this procedure it would be a clear indication
that the specific EEG training received by experimental subjects, rather than
any type of "placebo" effect, is what caused the improvements.
While these limitations are important to be aware of, the overall pattern
of findings reported add to the increasing evidence base for neurofeedback
as a treatment for ADHD. While many experts would argue that additional
studies are required to clearly demonstrate that this is an effective intervention
- and I personally agree with this statement - it is also important to recognize
that a number of studies provide converging evidence for the potential value
of this approach.
I will continue to publish summaries of new studies in this interesting
area in Attention Research Update as they become available.
Information presented in Attention Research Update is for informational
purposes only, and is not a substitute for professional medical advice.
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