Below is an abstract which I found. They are basically saying that the anterior regions of the corpus callosum are frequently abnormal in people who have adhd.

Intertestingly enbough, abnormalities in the posterior of the corpus callosum are found in autism and asperger's syndrome. But, the the case of Asperger's disorder, white matter abnormalities are sometimes gross and widespread, wheras in ADHD, TS and dyslexia, white matter abnormalities seem to be focused around the frontal lobes, and cortex areas. (I really had to DIG on the internet to figure that one out.)

Now I understand why some claim ADHD and Aspergers to be related. They really are different disorders, but they do share some of the same underpinnings in terms of brain structure abnormalities.

Me :D


Quantitative morphology of the corpus callosum in attention deficit hyperactivity disorder

JN Giedd, FX Castellanos, BJ Casey, P Kozuch, AC King, SD Hamburger and JL Rapoport
Child Psychiatry Branch, NIMH, Bethesda, MD 20892.

OBJECTIVE: By means of quantitative neuroanatomic imaging the authors assessed the hypothesis that there are structural brain abnormalities relevant to frontal lobe circuitry in children with attention deficit hyperactivity disorder (ADHD). METHOD: The midsagittal cross-sectional area of the corpus callosum, divided into seven sections, was measured from magnetic resonance images of 18 boys with ADHD and 18 carefully matched normal boys. RESULTS: Two anterior regions, the rostrum and the rostral body, were found to have significantly smaller areas in the ADHD group. These areas correlated in the expected direction with teacher and parent ratings of hyperactivity/impulsivity. CONCLUSIONS: This finding supports theories of abnormal frontal lobe development and function in ADHD.

Interesting -- thanks for sharing this Speedo!:)

Here is a link on the autism facts which I cited ...

http://ajp.psychiatryonline.org/cgi/reprint/154/8/1051.pdf

http://spnl.stanford.edu/publications/pdfs/Lotspeich_AutMRI_AGP04.pdf

and one for TS

http://cat.inist.fr/?aModele=afficheN&cpsidt=13425943


and one for dyslexia

http://news-service.stanford.edu/news/2000/march1/dyslexia-31.html


and more on ADHD

http://www.medscape.com/viewarticle/495640_2

Me :D

Wrong or right, here is my take on this info: If you are going to have adhd, ts, dyslexia, pdd, autism, or nvld, you can have it in one of two ways... Either too much white matter or not enough white matter in various regions of the brain.

The big difference between these disorders is the degree and extent of the white matter abnormalities.

In the case of adhd, ts, and dyslexia, the white matter abnormalities are more or less localized to specific areas of the brain.

In the case of nvld, pdd, and autism, the abnormalities are more global, and the difference between these disorders is more of a matter of degree.

Me :D

Speedo, could you please post the location and citation info on the article? I'd like to read the whole thing.

Thanks

thank you speedo inlighting artcal thanks again dormy

All I have is a link to the original publisher: http://ajp.psychiatryonline.org/cgi/content/abstract/151/5/665

The rest is a synthesis of that information and the remaining information which I mentioned.
ME :D

Speedo, could you please post the location and citation info on the article? I'd like to read the whole thing.

Thanks

There have been similar findings in trauma research in kids brains. (eg lateralization and communication from side to side does not work properly.)

I recall reading a comment from a neurologist once. It said something like the CC is good for two things: spreading of seizures (the signals travel), and holding the sides of the brain together. <G>

We can technically live w/o a CC. Kim Peeks ("rainman") has no CC (as well as an overdeveloped cortex, which likely explains the areas of high intelligence that he does have).


There have been "normies" who have no CC, apparently (eg 'split brain studies'); however having no CC does seem to be linked to the inability to use the brain (frontal lobe?) for higher-thinking processes.

I notice one article (wikipedia) where some suspected Aspergers cases may in fact be agenesis ('non-development') of the CC.

It seems like an interesting little gizmo.

It is interesting how new research is always coming out. I recall that it used to be taught that the Cerebellum was irrelevant, except MAYBE to some motor coordination. It turns out that it's becoming increasingly recognised in its contributions to OTHER brain functions.

I ran into a few studies on agenesis of the corpus callosum on the internet. There was one remarkable parer on a 12 year old boy with no CC who appeared to be normal, but complained of headaches. There are also a number of studies of agenesis of the cc in autistics... it seems it is rather common in autism.

The sense that I get is that in AS there is a tendency to have more whitematter but not uniformly so, and some areas of the brain may be underdeveloped for white matter. In the case of autism the reverse seems to be common... less white matter, but again, nonuniform, and some areas may be "normal" and others defecient.

This insconsistency in white matter is why I tend toward thinking that it is not either just absence or surplus of white mtter... it is the act that white matter is in an abnormal abundancy... either plus or minus... and you end up either with ADHD, Ts, dyslexia, or into some for of autism, depending on how it all stacks up.

It kind of fits into the fact that some famileis will have a few ADHD siblings and one (or more) autistic members.
I guess it is all about genetics...

That is an interesting note about the rainman. He is a remarkable fellow, and quite lucky, cosidering how difficult his condition has been for him.

I hate to get stuck on it, but the comparison between AS and ADHD in the CC is remarkable. I think I chose the wrong career, neurobiology is SO fascinating.

Me :D

Forgive my ignorance here.... I may have heard of white matter before, but I obviously didn't consider it important enough to remember it. :) Does this pretty much cover it?

Wikipedia says:
Generally, white matter can be understood as the parts of the brain and spinal cord responsible for information transmission (axons); whereas, grey matter is mainly responsible for information processing (neuron bodies).The corpus callosum is a structure in the mammalian (http://en.wikipedia.org/wiki/Mammal) brain that connects the left and right cerebral hemispheres (http://en.wikipedia.org/wiki/Cerebral_hemisphere). It is the largest white matter (http://en.wikipedia.org/wiki/White_matter) structure in the brain, consisting of 200-250 million contralateral (http://en.wikipedia.org/wiki/Contralateral) axon (http://en.wikipedia.org/wiki/Axon) projections. It appears as a wide, flat region just ventral (http://en.wikipedia.org/wiki/Ventral) to (below) the cortex (http://en.wikipedia.org/wiki/Cerebral_cortex). Most (but certainly not all) communication between regions in different halves of the brain are carried over the corpus callosum.Also interesting to me is the following comment (also fr wikipedia): Newsweek (http://en.wikipedia.org/wiki/Newsweek) stated in 1992 (http://en.wikipedia.org/wiki/1992) that the corpus callosum was "Often wider in the brains of women than in those of men, it may allow for greater cross talk between the hemispheres—possibly the basis for woman’s "intuition (http://en.wikipedia.org/wiki/Intuition_%28knowledge%29)". It has also been used, for example, as the explanation of an increased single-task orientation of male, relative to female, learners; a smaller male organ is said to make it harder for the left and right sides of the brain to work together and to explain a feminine ability to multitask.
White matter irregularities would explain a lot, seems like....the extract said that the anterior sections of the cc are involved in frontal lobe circuitry. Anyone have a simple way to explain that?

Yes. IT can be explained in plain english.

White matter in the brain is basically nerve fibers. The corpus callosum is a very densly packed bundle of nerve fibers that acts like the "wiring" for much of the brain. It interconnects the hemispheres, and the various regions of the brain and interfaces to the cortex (the inner brain).

If the corpus callosum is abnormal, you can expect to have problems with connectivity to various parts of the brain, depending on where the abnormality is, and how great the abnormality is.

In the case of adhd it is the front part (called the rostrum) of the corpus callosum which is often abnormal, which leads to problems with connectivity to the frontal lobes.

This can also explain the tendency for some people to overload due to inadequate (or too much) connectivity between regions of the brain.

ME :D

I've been wondering lately whether ADHD could be considered part of the autistic spectrum. I have one son with ASD/ADHD and the other who is just ADHD, and it's really interesting to compare them. They both have sensory processing disorder to different degrees, and the incidence of families with ADHD who also have ASD seems quite high. I've been thinking that where Aspergers and HFA are considered the 'higher' end of the autism spectrum, perhaps they should be looking at ADHD as being the higher end of the spectrum. I find the brain and how it works fascinating.

The researchers point out that adhd and autism are distinctly different disorders. I thikn I agree with that Idea... but there are some people who argue that ADHD is in the autism spcrtum.

ME :D

The researchers point out that adhd and autism are distinctly different disorders. I thikn I agree with that Idea... but there are some people who argue that ADHD is in the autism spcrtum.

ME :DHave you seen the book The ADHD-Autism Connection by Diane Kennedy? She's a mother with kids in both camps -- she has some interesting insights on the subject -- both citing both research and mom's observations.

Scattered

The rapidity with which google picked up this thread is amazing.

A google search for the keywords;

white matter adhd corpus callosum

Turns up several links to this thread on the first page.

Me :D

... an image to assist ...

http://www.nature.com/npp/journal/v30/n3/fig_tab/1300617f1.html?url=/npp/journal/v30/n3/full/1300617a.html#figure-title

[J]Neuropsychopharmacology
[T]Reduced Anterior Corpus Callosum White Matter Integrity is Related to Increased Impulsivity and Reduced Discriminability in Cocaine-Dependent Subjects: Diffusion Tensor Imaging
[A]Frederick Gerard Moeller ->- Ponnada A Narayana

Corpus Callosum in red

http://www.nature.com/npp/journal/v30/n3/images/1300617f1.jpg

some one has to disagree. I guess it is my turn today.

referencing this source, which I normally respect. Heck I subscribe to thier publication and participate in their forums occasionally. I guess no one agrees with every one 100% of the time.

medscape (http://www.medscape.com/viewarticle/495640_2)

Neuropsychologic studies on children with ADHD have revealed a pattern of cognitive deficits consistent with prefrontal executive function deficits: inattention, difficulty with self-regulation, response inhibition deficits (impulsivity), restlessness or hyperactivity, or apathy in some cases.[34] However, depending on a number of methodologic variables, including subject and control group selection and the presence of certain comorbid disorders, the results have been somewhat variable

Results have been some what variable like duh?

Outside of the dyslexic spelling here exactly what is proven by inconsistent “variables”?. They make some pretty bold statements for folks who can’t seem to make up their minds .



This suggests the intriguing possibility that the essential dysfunction in ADHD involves inattention and disorganization rather than hyperactivity or impulsivity, as has been believed, and that hyperactivity or impulsivity might result from some other factor.

They also seemed to have forgotten that it was the hyperactive ADD varieties that were the "original" ADDers in the first place. Geez. . .. .to think I am accused of having a working memory deficit, but the above forgetfulness is considered "normal"! Boy was I born on the wrong planet.




Studies on normal individuals have shown that the caudate decreases in size as the child matures (a manifestation of the normal "pruning" of neurons seen in many parts of the brain during development). Children with ADHD start out with smaller caudate nuclei than controls, and with maturation, there is a further decrease in size. As a result, any difference in size between children with ADHD and controls becomes less apparent with increasing age.

Huh? Okay being born with less means we loose less.. . . . . . ."controls become less apparent with age". . . . . it all comes out in the wash?




. Given the important role that the right hemisphere plays in regulating attention and the deficits seen in ADHD, it would not be surprising to observe reduction in right frontal lobe volume. This was not a consistent finding, but it was noted in a number of studies.

It wasn’t a consistent finding but we are going to pretend that is was. . . . .




This asymmetry was not necessarily observed in all studies, but they generally involved many fewer children and were not longitudinal.

So this observation of asymmetry could not possibly be limited to a sub-group of individuals who have similar characterstics that resemble ADD. . . .or perhaps this applies to only a percentage of the ADD population. . . . . the other study results don't jive with this point of view therefore "they" must be the ones who are wrong?




A number of studies reported a reduction in the area of the anterior[42,44,62-64] or posterior corpus callosum.[65] However, in the large National Institute of Mental Health study, this was not confirmed

i.e. they didn’t find the same thing. . . . . .:faint:




Although this study was not without methodologic problems (it involved a small number of subjects, the "controls" were siblings of the ADHD subjects, and the findings were significant only when computed without adjustments for multiple statistical comparisons), it still suggests that the dopaminergic system is dysfunctional in persons with ADHD.

~Underlining mine~

The presumptions made on studies with inconsistent measurements, inconsistent findings but interpretations are strangely consistent with main stream conclusions . . . . .couldn't have thing one to do with those "methodological problems"?




A control task was also employed. Adults with ADHD did not activate the prefrontal cortex during the decision-making process to the same extent as did the controls and did not activate the anterior cingulate and hippocampus, which are involved in emotional arousal and memory. However, the subjects with ADHD activated the posterior right anterior cingulate more than the controls.[77]

I little research into previously mentioned brain parts obtained from a source not involved in ADD research,(thus neutral) we find:

The posterior cingulated is believed to be involved with visuospatial behaviors, postsaccadiac neuronal responses and spatial memory.

The anterior cingulated is believed to be involved in motivation, attention, memory, involuntary responses for motor and autonomic reactivity.


This is saying that people with ADD activated a different area of the brain. Different doesn’t mean dysfunctional unless we apply the contextual to this equation. . . . . . .



. However, diagnostic accuracy is not much better than the clinical assessment and requires specialized equipment and technical expertise. Given the possibility that there can be different EEG patterns seen in children with ADHD, this technique appears to have limited application at this time; however, it might be useful in determining the response to medication[82] and possibly will be more meaningful once ADHD genetics are unraveled.

In summary, electrophysiologic studies of children with ADHD reveal atypical brain wave patterns, which suggest dysregulation of arousal and attention.

~Bold and underlining mine~

Major wtf??? Okay first using the EEG wasn’t any more accurate than an psychological exam(trained observation), that due to the different EEG patterns seen in children with ADD (ie it is defiantly different but we don’t know how) so "use of this method has limited application at this time" (we’re hoping the guys in genetics come up with some thing better because this is a bust) but EEG studies suggest a dysregulation!!! How??? If the dysregulation is so obvious then use of EEG shouldn’t be so limited! :rolleyes:

That is all I have right now, thanks for reading and thanks for sharing this article.My disagreement doesn't decrease my appreciation of the effort put forth in this presentation.

SB you must have posted when I tried the first time. . . .got the circle round and round!

So... is there any evidence of actual brain difference between children that were diagnosed and medicated early vs. those who weren't? As in, does medication ever actually improve the structure of the growing brain, or is it strictly a matter of helping the synapses work more effectively?

I've read that withe matter associated with the frontal lobes increases in children who are treated for ADHD. The stimulants actually cause the brain to create more white matter.


ME :D

White matter in the brain is basically nerve fibers.

I've read that withe matter associated with the frontal lobes increases in children who are treated for ADHD.
The stimulants actually cause the brain to create more white matter.
The number of power lines increase.
Not the ALU - the chubby bits in the middle of the lines.
This idea'd maybe be a bit counter-intuitive when first considered.

A better mind - conditional on better interconnectivity between cortical space and the more ancient realms - but->->->- (and I need to mention that I haven't read any of the studies describing Speedo's observation - immediately above) - but
->->->-
-A better mind on account of
...a closer juxtaposition between higher and lower realms
...of greater patterns of interonnectivity
and
...on more and better power lines.

So - the above three may be representative (respectively) - of the following observations made on ADDF ...
-a-balancing reality ->- the physiological purpose of depression
-b-the metamodel web representing a more efficient store of logical information within the same physical space
-c-that the brain is a data-driven engine - with sole 'desire' to fire - neurotransmission.

So -a- ... not sure - maybe balancing reality would be an entirely higher affair ... will think on ...
-b- ... again - not sure - the logical structure - I guess would only be represented in cortical space - we briefly visited the idea of the more complex structure permeating into autonomous control regions of the brain - but that plain just wouldn't work - or rather we wouldn't work ...
-c- ... now this is the bomb.

Pretty sure that laying down more data lines would be just what the brain's prime directive would order.

Imagine - a happy brain - is an electric brain.
Sizzle sizzle.
Incidentally - pleasantly electric - and not frazzled to a cinder.

... So Speedo - no more xtreme-over_uber_overclocking :-) ...

So - I guess - the natural next question then might be - so what gives?
... more corpus callosum and less ...?...?...?...

... So Speedo - no more xtreme-over_uber_overclocking :-) ...http://www.addforums.com/forums/showpost.php?p=354223&postcount=17
I can also multitask like crazy but I run a risk of overloading suddenly... sometimes with rather dramatic consequences...
...:-)...

My comments are largely syntehsis of the bulk of what I"ve been rading. It's an observation, fodder for discusssion more than a declaratoin of fact.

Yes, I hae the brakes on full, but they don't work so well.

Me :D

Here is another abstract on the topic of adhd and corpus callosum abnormalities.

The authors basically said that they studied 7 adhd kids and found that they had smaller corpus callosum than most people, and that ADHD probably is more complicated than cc abnormalities alone.

ME :D

http://eric.ed.gov/ERICWebPortal/Home.portal?_nfpb=true&_pageLabel=RecordDetails&ERICExtSearch_SearchValue_0=EJ427044&ERICExtSearch_SearchType_0=eric_accno&objectId=0900000b8002cf19

... how about this for an idea?
The brain is switching from from grey into white matter - switching from a discernible structure [cell bodies clearly visible between axons and dendrites] {and these connected to one another)
->- to a structure which is more akin to a tremendous mass of spaghetti
... that is (for the most part) - the neuronal cell without any apparent structure - giving way to a new form which is (for the most part) - simply a myelinated axon with connections (junctions (nodes)).

Strikes me - that if the drive towards increased complexity is realised by a complex physical structure supporting the ever more complicated logical structure of mind - that the components of brain - will have to change to provide the capacity for mind to move forwards -
- and I think it kinda' figures that this is the mechanism for achieving complexity which biology is likely to choose - given past precedent ... ... ... {at least} ... ... ...

Do you see the pattern in (http://www.addforums.com/forums/showpost.php?p=336690&postcount=3)?
http://www.addforums.com/forums/showpost.php?p=336690&postcount=3
uni ->- bi ->- multi ->- pyramidal

... the chubby bit's dieting itself outta' existence ...

Okay, lets have some fun with this. :)


Using a computer as an analogy;

the brain is a massively parallel computing machine.
many small cpu's.
individual cpu's rely on interconnecting network to share information.

if individual cpu's are slow in computing solutions, their data is dropped from the queue of information. (ADD attention problems, etc)

grey matter==processing areas
white mater==network circuittry interconnecting processing areas

too little white matter -->> overloaded connecting network -->> processing difficulties, low bandwidth I/O -->> slow processing speeds.

too much white matter -->> overloaded processing areas -->> processing difficulties, out of cpu time -->> slow processing speeds.

too many cpu's dropping data results in a greater degree of disorder.

two different problems yielding the same results.

ME :D

The number of power lines increase.
Not the ALU - the chubby bits in the middle of the lines.
This idea'd maybe be a bit counter-intuitive when first considered.

A better mind - conditional on better interconnectivity between cortical space and the more ancient realms - but->->->- (and I need to mention that I haven't read any of the studies describing Speedo's observation - immediately above) - but
->->->-
-A better mind on account of
...a closer juxtaposition between higher and lower realms
...of greater patterns of interonnectivity
and
...on more and better power lines.

So - the above three may be representative (respectively) - of the following observations made on ADDF ...
-a-balancing reality ->- the physiological purpose of depression
-b-the metamodel web representing a more efficient store of logical information within the same physical space
-c-that the brain is a data-driven engine - with sole 'desire' to fire - neurotransmission.

So -a- ... not sure - maybe balancing reality would be an entirely higher affair ... will think on ...
-b- ... again - not sure - the logical structure - I guess would only be represented in cortical space - we briefly visited the idea of the more complex structure permeating into autonomous control regions of the brain - but that plain just wouldn't work - or rather we wouldn't work ...
-c- ... now this is the bomb.

Pretty sure that laying down more data lines would be just what the brain's prime directive would order.

Imagine - a happy brain - is an electric brain.
Sizzle sizzle.
Incidentally - pleasantly electric - and not frazzled to a cinder.

... So Speedo - no more xtreme-over_uber_overclocking :-) ...

So - I guess - the natural next question then might be - so what gives?
... more corpus callosum and less ...?...?...?...

can we add a little connectionism into your model :-) ?
http://www.addforums.com/forums/showpost.php?p=356601&postcount=19

... noting that we're really after a kinda' massively parallel processor whose only real function is to pattern match.

see image =>= afferent input
pattern match = your dog
tickle dog =>= efferent output

pattern matching + connectionism

Yes, and the network topologies of the various processing areas is a fractal pattern with a dendritic habit not unlike a tree. In terms of man-made computing machines it would suggest that the topology of the interconnecting network lends itself to efficient processing of data using a reentrant style, where the input data of one processor is taken from the output of the one further up the tree. This style of computer program tree traversal is referred to as "depth first" , where the processor traverses to the very top of the tree and works it's way back, thus exploring one branch at a time... starting at the leaf at the very end of that branch. It's also possible that multiple processors could span different branches of the tree concurrently, thus providing a speedup... But one has to consider that not all processes can be executed in a parallel fashion, so the brain MUST do some things in a serial fashion , and others in a parallel fashion...

In terms of what goes wrong... if the ability of the network to transport information is impaired by a lack of connectivity, many processors are either unavailable , or become very slow due to the loss in bandwidth. In a parallel processing environment, the entire process is no faster than the slowest individual component, no matter how many processors are allocated to the task.

To make matters more interesting, it seems likely that individual processors have access to each oteher via the network tree. This assures that reentrant processing is truly possible by mearely adding more processors to the task as-needed, while processing is occuring. This kind of on-the-fly resource allocation is a dream for high performance computing fans, but the human brain seems to do this kind of thing routinely. It assures redundancy in case individual processors fail or error, and it allows for "fuzzy logic" to be applied to arrive at solutions that must be "guessed at". Furthermore, it also allows a dyamic allocation of resources so that unused processors are freed up right away.

To the mind it is all transparent just as the internal clockwork of a pocket watch is not obvious to it's owner. The watch merely tells time as far as the user can see... If the regulator inside the watch malfunctions, all the end user can perceive is that the watch no longer keeps accurate time.

Likewise, a defecit in a tree-like array of small processors would likely result in a significant slowdown of processing, with no apparent locus of cause for the slowness because the problem is in the network, not the processing.

Me :D

In a nutshell, what I'm trying to say is that the mind does not reside in the structure of the brain. The mind exists because of the properties of the "hardware", much like the operating system of a computer merly runs on the comuter hardware, but is not the hardware itself and is thus an abstraction of the computer's capabilities, not the computer itself.


This means that when something goes wrong, we experience a change in the character of the abstraction, and our mind percieves some difficulty in some aspect of our day-to-day functioning.

In any case. I have wandered perilously off-topic.
How does this relate to connectivity theories and adhd, autism, etc ?

What we need is more information about white matter abnormalities in adhd, autism, etc... so that we can compare and contrast, and maybe get a better understanding of why people have adhd, ts, ASD, etc...

ME :D

Oh... I recently had a conversation with an MD about white matter abnormalities and ADHD. He agreed with my notion that ADHD is a "wiring error" in the brain, but was skeptical of the reports of white matter abnormalities that are based on mri results. He seemed to feel that statistical analyses of MRI is an inadequate tool for interpreting ADHD, and was nothing more than an educated guess.

ME :D

ooo heck!
... back in an ADDer minute :-) ...

In a nutshell, what I'm trying to say is that the mind does not reside in the structure of the brain. The mind exists because of the properties of the "hardware", much like the operating system of a computer merly runs on the comuter hardware, but is not the hardware itself and is thus an abstraction of the computer's capabilities, not the computer itself.... perfect :-)

off-topic?

it's all connected.

:-)

... the entire process is no faster than the slowest individual component, no matter how many processors are allocated to the task.... ...

can this idea be incorporated?

http://portal.acm.org/citation.cfm?id=847234
from
http://www.addforums.com/forums/showpost.php?p=236090&postcount=10

Let me take you down,
Concentric Hyperspaces and Disk Allocation,
for Fast Parallel Range Searching,
cause I'm going to strawberry fields,
Abstract Data partitioning and declustering
have been extensively used in the past
to parallelize I/O for range queries.
Nothing is real,
Several index structures are proposed for
efficient range, partial match, and
similarity searching traditional databases.
and nothing to get hung about,
If the data space is divided into two parts,
in each dimension, referred to as balanced
binary partitioning -- 13 dimensions, range
query with sides of length 0.5, volume
10\Gamma 4 of the whole data space,
Strawberry fields for ever................
Decreasing the length of the sides of range
query will result in low selectivities.

This problem becomes more acute in higher dimensions.

StrawBerry fields for ever................

and

how does CMAC compare to your pattern matching scheme?