“Different” Brain Connectivity Linked to Social Impairments
Using functional magnetic resonance imaging, researchers affiliated with the University of Washington’s Autism Center have found an “abnormal pattern of connectivity” in the brains of autistic adults; this different neurological “wiring” may be responsible for social impairments that are one feature of autism. The study, which is published in the journal Brain, focused on the brain regions that process faces, the fusiform face area. From today’s Science Daily:
The research team led by Elizabeth Aylward, a UW professor of radiology, examined connectivity in the limbic system, or the network of brain regions that are involved with processing social and emotional information. Participants in the study included 19 high-functioning adults with autism who had IQs of at least 85. They ranged in age from 18 to 44 and were compared with an age- and intelligence-matched sample of 21 typically developed adults. The group with autism spectrum disorder included eight individuals diagnosed with autism, nine with Asperger’s syndrome and two diagnosed with pervasive developmental disorder not otherwise specified. The level of social impairment for each autistic participant was drawn from records of clinical observations and diagnoses that confirmed that each had autism.
Each participant had his or her brain scanned while looking at pictures of faces or houses. Participants were shown four series of 12 pictures of faces and a similar number of series showing houses. Each individual picture was seen for three seconds. Occasionally the same face or house picture was repeated, and participants were told to press a button when this occurred.
The two groups’ performance in these tasks did not differ significantly, but the groups exhibited different patterns of brain activity.
Compared to the participants with autism, the typically developing adults showed significantly more connectivity between the fusiform face area and two other brain regions, the left amygdala and the posterior cingulate. In addition, autistic participants who had the largest social impairment showed the lowest level of connectivity between the right fusiform face area and the left amygdala and increased connectivity between the right fusiform face area and the right inferior frontal gyrus.
The brains of autistic people, according to the study, do not work as “cohesively” as the brains of those without autism.
My son has a great memory for people —- certainly for every teacher and therapist who has worked with him and close relatives —- though I wonder if it’s not their faces that he might remember, so much as their voices, how they hold their bodies, and other features. He’s attuned to something else besides just their faces—while autistic individuals may process facial information differently, perhaps this enables them to see other things and notice what gets missed?
Tags: asd, asperger, autism, autism blog, brain, brain blog, mri, Neuroscience, parents, pdd-nosRelated Stories
POSTED IN: Neuroscience
15 opinions for “Different” Brain Connectivity Linked to Social Impairments
Matt
Jun 12, 2008 at 7:18 pm
I have to ask, “witing”? I’m figuring that this is either a new word to me, a mispelling of “writing”, or, Elmer Fudd is the PI of the study!
That bit of silliness aside–I would wonder about the simultaneity of the signals reaching different parts of the brain. My recollection is that U Pitt (?) researchers last year showed that certain areas of the brain fire at different times in autistic people and at the same time in NT people.
Very cool stuff, the UW research. I don’t expect this UW project to be brought up by the Petitioners in the Omnibus like they relied on the Burbacher study though.
Melody
Jun 12, 2008 at 7:28 pm
Cool! Yeah, while I have poor eyesight and facial recognition, I can often recognize one of my parents when they’re quite far away if they’re walking, or if I can hear their footsteps when they’re in another part of the building. Similarly for my sisters and friends.
Also the voice is what I usually recognize first. One of my friends recently was in a performance singing opera and I hadn’t recognized her onstage at all until she started singing an aria, at which point I knew it was her immediately.
Cliff
Jun 12, 2008 at 7:59 pm
Don’t take this the wrong way, as to make me sound like I’m criticizing the study as to make it invaluable per se (because I’m not; I actually find in it some very interesting information indeed).
But I’ve always wondered how much people are asserting into a chicken-and-egg question with the framing of these studies. I mean, if someone, for whatever reason, isn’t being stimulated by some message, wouldn’t it be expected that there be less brain activity in certain areas? And then, because of that lack in certain areas, perhaps more in others as per being focused on something else? As opposed to that lack of activity being the reason for the social deficits? It’s not a criticism, just a question, really.
Cliff
M
Jun 12, 2008 at 8:21 pm
“perhaps this enables them to see other things and notice what gets missed?”
Doorknobs. I have a vibrant memory for doorknobs. I loose sleep over them. Actually, it’s the texture of doorknobs. I don’t know. I may just need a hobby. A less knobby hobby.
daedalus2u
Jun 12, 2008 at 9:08 pm
I think it is exactly correct that a brain optimized to be good at one thing isn’t going to be good at something else. The size of the brain at birth is limited by the mother’s pelvis. What that brain is optimized to be good at is what it will be good at. Better to be good at something than crappy at everything.
M
Jun 12, 2008 at 9:09 pm
(i adoor them.)
Ms. Clark
Jun 12, 2008 at 9:32 pm
M, One thing about door knobs, they’re a-door-bell. :-)
M
Jun 12, 2008 at 9:37 pm
Hee. You win points.
Kristina Chew, PhD
Jun 12, 2008 at 10:10 pm
“witing” could be–
1) whiting?
2) writing?
3) wit thing
4) wiring…
5) wot hapns wen ur son hs waitd long enuf 2 go 2 the pool.
Kristina Chew, PhD
Jun 12, 2008 at 10:12 pm
Need to look up that study you cite, Matt.
I also wonder, why is it so often “facial identification” that gets tested? As noted in this thread, there are plenty of other ways to recognize people.
Xeno
Jun 12, 2008 at 10:39 pm
(Matt asked: “‘witing?’ I’m figuring that this is either a new word to me, a mispelling of ‘writing’…”)
It’s “wiring” of course. Not sure if you were joking…
Since they used functional MRI, they must have been measuring “functional connectivity”, which is the tendency for brain areas to be activated at the same time, just as you described. The assumption is that functional connectivity reflects the way two areas are physically “wired” (the more correlated the activity, the more efficient or numerous the “wires.”)
I’m not sure this assumption is warranted, and I’m very skeptical of fMRI in general. There’s even less justification for assuming that any difference in activity is a defect. (The actual title was “‘Faulty’ Brain Connections May Be Responsible For Social Impairments In Autism.”)
Kristina Chew, PhD
Jun 12, 2008 at 10:42 pm
I noted the “faulty”—-I was rushing because Charlie had been waiting too long to go swimming. Checked the html but obviously not the spelling.
Or maybe it’s my faulty wiring in action.
daedalus2u
Jun 13, 2008 at 7:15 am
There is a gigantic difference between “actual” connectivity and “functional” connectivity.
Each neuron has ~10,000 connections (or more). Those are the actual connections.
When a neuron fires, on average only one downstream neuron fires in response. If more than one fired (on average), the number of neurons firing would increase exponentially until they were all firing (a massive seizure). That doesn’t happen, so we know the average is 1. Those are the functional connections.
The actual connections control what it is possible for that brain to do, the functional connections are what that brain is actually doing.
Actual connections are extremely difficult to determine even on postmortum. Functional connections are too, but with fMRI patterns of activity can be mapped in the brain and when activity in one area follows from activity in another area, the inference is that the first activity caused the second and so there is functional connectivity between them.
The mapping that fMRI does is no where close to the single cell level. The volumes seen to be activated contain many cells, at least hundreds of thousands. The details of what is going on with each of those cells is completley smeared out in the averaging that goes on during the measurement.
Marcie
Jun 13, 2008 at 9:01 am
This study actually sounds a lot like what I keep saying about the connection with frontal lobe syndrome (disconnection of emotion and intellect) and autism. The connection of emotions and intellect is where social intuition comes from. Antonio Damasio describes frontal lobe syndrome (though not autism) in “Descartes’ Error”.
Patrick
Jun 13, 2008 at 2:48 pm
This kind of reporting has been going on for at least 2 years that I know of, volume calculations, fmris, etc, linked to processing functional areas. I hope something useful comes of it all.
@daedulus2u, isn’t that pelvis statement a bit shallow considering pelvic expansion and c-sections?
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