The journal article found at the link below says that ADDers are more likely to have macrocephaly than autistics, but less so than those with asperger's syndrome.

why ?

http://journals.cambridge.org/article_S0012162201002110

me :D

Speedo are you "in a mood" to make me do research? My dish pan hands are killing me, my brain apparently will soon follow. . . . .

:-) whoa Tammy :-)

...Wikipedia drives us back to corpus callosum...
http://en.wikipedia.org/wiki/Macrocephaly (http://en.wikipedia.org/wiki/Macrocephaly)


Notable people with macrocephaly



Kim Peek (http://en.wikipedia.org/wiki/Kim_Peek)
Albert Einstein (http://en.wikipedia.org/wiki/Albert_Einstein)

Apparently Cambridge is currently witnessing a significant increase in head size at birth (from med. friends).
Funny that.

... so - weaving these various ideas together - we have a well-developed cortex sitting above the corpus callosum - almost as though it's [CC] a relay between that separate subsystem [cortical higher centres] and the more ancient parts of the brain below.
The reward circuitry occupies a position close to the centre of the brain - within an 'ancient region' ... if you like.

The most ancient parts [btw] of the brain are the anatomical regions around the stem.

We have the need to store information within the brain - we live in an information rich age - and so in an environment of access to such large amounts of information - we can increase the size of our hard drive - or increase the efficiency with which we lay down information (compression).

Efficiency might initially (a little bizarrely - but not really) - present as a decrease in brain size [remember the stories about ADDers having small brains - they're referenced on ADDF quite some - I'll dig a couple out if you like] - though one would expect that under the demands of ever increasing information upload - that the transient decrease in size (transience on the scale of human evolution (though better - evolution on the sale of evolution of modern man)) - would be *reversed* - and the new efficient structure would extend its logical struture into an increased size of physical structure - a larger brain.

And thereafter - in a triumph of neuroplasticity - into physical spaces which're just not as useful to its prime directive.
:-)
Hold onto the thought that the brain's prime directive is to fire.
Neurotransmission.
Also that this idea is represented within the concept of the 'selfish logical model' - I believe the 'meme' ... (I think).

->-returning->-

Noting that there're biological limitations on brain size.
The switch to a more efficient encoding of reality - would likely occur in a graded manner - a kinda' spectrum - I guess one could say.

why?

Genetic card shuffling and trait dealing. We have a half deck of cards from each parent they get shuffled and thraits dealt out. ADD is more than some EF deficient thing, in my opinion.

Sorry for the slow response. . . . .
I read the article about 30 minutes ago but have been distracted several times by partner trying to figure out new server navigation (some thing I have learned to eliminate completely).

One research study posted says ADDers have smaller brains, now we are talking larger. . . . . . .more scientific fickle findings to boggle me brain. . . . . .


ADD is a part of our make up as much as our gender, hair color, and height. We are different it is in the contrast of social expectations that causes dysfunction / disorder. Before clocks existed was running ten minutes late really as much of a problem as it is today. In human social history before vocalized language would not the first ballad have been considered dysfunctional, the first poem spoken aloud a behavior problem. . . .Our genetics gives of ranges of traits, characteristics however it is those genetic interactions with our environment that effluences expression. A man can be genetically predisposition ed to grow 6 foot 2 however if malnourished while in the growing stages it is a safe bet he will not reach that height. . . . .genetics and environment are two separate things and that are inseparable thus my point.

Time for meaad823 to introduce her body to the bed, work day tomorrow will give me a break from the reverse packing. Good nite all.

Iv'e recently read that the earlier claims of brain mass loss in adders was mistaken. It turns out that grey matter does decrease in the frotal lobes, but white matter increases in the frontal lobes so the total brain volume stays the same. Apparently the frontal lobe in some adders is smaller than normal (which would explain why they have ADHD in the first place!).

Now, to make things more confusing.. consider the posts on the corpus callosum thread... researchers are saying that ADDers have white matter loss in the corpus callosum...which has the white matter fibers that connect to the frontal lobes in the first place.... What is with this ?

How does all of this syntesize into the big picture ?

As far as I can figure out it possibly means that we lose white matter in some places and gain it in other places when we have ADHD.....

So why do ADDers have greater head size ? If one belives that study it occurs a little more often in ADDers than in autistics...

I don't think that greater brain size means anything. Indeeed, some of my recent searches turned up info (a study on aspies) that suggests that IQ is closely tied to the ratio of white matter to grey matter, and that brain size is not much of a factor in determining IQ. It seems that more white matter equates to more IQ.

So if it is not some kind of adaptive genetic trait, why do ADDers have a bigger head size than non-adders ?

Has anyone read anything about ADD brains having white matter fibers packed too densely (an indication of crowding inside the brain case). I know that some autistics have this, and that some autistics have a great excess of grey matter as compared to white matter.... which would explain the need for a larger skull.

ME :D

Maybe ADDers have a larger head size just because ADDers have a larger head size ????
:eek: :p :)

ME :D