I guess you haven’t read Ms. Hewitson’s response to the critique Steven Novella submitted to the journal?

Factually incorrect. I focus on the poor study. Ironically, you are doing excatly what you blame me of—attacking the person rather than the message.

you appear to be doing a cut and paste from a blog post which linked to mine.

“Having a conflict of interest doesn’t invalidate the study.”

Please educate those who throw out any study funded by or performed by the CDC or drug companies.

“Although it’s a just a pilot study, the fact that there was a statistically significant connection between the exposed group and autism shouldn’t be overlooked.”

First—statistically significant and connection are different things. A statistically significant correlation could suggest a connection but it is not a connection.

Second—I don’t think the data above are good enough to claim a statistically significant result. Based on the data that are out on amygdala sizes in growing macaques, the noise is too high. There are a lot of scatter in the measurements and the authors above are not taking that into account.

“We purposefully assigned a larger number of animals to the exposed group in order to optimize the chances of observing what we anticipated to be an uncommon or idiosyncratic effect.”

Too bad for them. They purposely made it difficult to get statistical significance. Much more to the point, too bad for the laboratory animals whose lives were wasted.

“The study is listed as a pilot project and indicates a causal relationship between the vaccine schedule and autism spectrum disorders. If people were really interested, they would follow up on this study:”

If the people promoting Ms. Hewitson’s research really cared, they’d know that Gene Sacket is doing a followup on the study.

The study does not attempt to explain anything. The authors “attempt” to do a great deal. They are, unfortunately, limited by the very poor design and execution of this study.

Having a conflict of interest doesn’t invalidate the study. There were 4 other authors involved in the study yet you completely focus on Dr. Hewitson as if discrediting her is going to discredit the entire study. This shows an obvious bias.

The study in question does attempt to explain the decrease in brain functioning (and therefore volume):
“Maturational changes seen in the experimental setting may be relevant to
the observed decline in [11C]DPN-binding in the unexposed animals over time. In rats, [MET5]-enkephalin, ?-endorphin, and opioid-receptor levels in the cerebellum reached their highest level in the first few weeks post-partum, and subsequently declined to low levels (Tsang et al. 1982, Zagon and McLaughlin 2004). Others have demonstrated a significant 2- to 4-fold
decrease in the concentration of opiate receptors in human fetal brain tissue during the last trimester of pregnancy (Kinney et al. 1990). This may be attributable to a normal process of programmed neuronal apoptosis that can extend into infancy, and is consistent with the enlarged amygdala volume and [11C]DPN-binding in exposed animals over time that was observed here.”

The study is listed as a pilot project and indicates a causal relationship between the vaccine schedule and autism spectrum disorders. If people were really interested, they would follow up on this study:
“the results of this pilot study warrant additional research into the potential impact of an interaction between the MMR and thimerosal-containing vaccines on brain structure and function.”

The authors address the small sample size here: “While, as a pilot study, the size of the study groups limits the strength of the conclusions that can be drawn, the use of statistical modeling and repeated measures contributed to the study’s power and increased the accuracy of the estimates.” and here:
“We purposefully assigned a larger number of animals to the exposed group in order to optimize the chances of observing what we anticipated to be an uncommon or idiosyncratic effect.”

Although it’s a just a pilot study, the fact that there was a statistically significant connection between the exposed group and autism shouldn’t be overlooked.

– pD

Something I learned just after I posted this: Apparently there are at least some reports that shrinking of the amygdala, among other parts of the brain, is reported in AUTISTIC children. So, if Hewitson’s observations are accurate, and reveal anything of potential interest related to autism, it is that at least one UNvaccinated monkey developed autism-like features.

I was struck by that too. It immediately made me think of a hematoma, though I don’t know if it would look like this. After looking into it a little further, I think it’s simply a space between the hind brain and a low-hanging piece of the frontal lobes. Something it helped me to remember: These MRI scans are, effectively, two-dimensional representations of a three-dimensional object, and as such all kinds of weirdness is possible merely from misleading appearances.
I hope to get the essay up in the next 24 hours or so.

I don’t understand why Mark Blaxill and Lyn Redwood are promoting this failed study, since the sloppy work, its promotion by SafeMinds and Age of Autism, and the vigorous suppression of the truth at Age of Autism provides additional conclusive proof to those who accuse SafeMinds and Age of Autism of ignorance, bias, and of being anti-science. That’s just wacky.

Even if Hewitson et al. hadn’t shot themselves in the foot (or head) by using a ridiculously tiny control group, it happens that these studies are actually technically difficult, as “obtaining volumetric measures in infants is … difficult, as structures are less well defined and largely unmyelinated, making segmentation challenging. Moreover, it is still unclear whether individual anatomic variation across development, in healthy, normally developing infants, is reflected in the configuration and function of the mature brain.” [“Neuroimage. 2010 Feb 1;49(3):2791-9. Epub 2009 Oct 19]

Of course, it’s actually a bit odd to focus on amygdala development in macaques who, like these animals, were removed from their mothers as neonates, since that in and of itself affects the amygdala.

This is just as comical as SafeMind’s support for the laughable Uhlmann (and Wakefield) study despite what may be the most thorough takedown of a paper in the history of molecular biology. I don’t know why Blaxill chose to have “LOSER” tatooed across his forehead, but it is remarkable that he can’t read the the word when he looks in the mirror—everything’s backwards for him, I suppose.

I’m wrapping up a response to this study. My major conclusion: Hewitson was only willing to claim “statistically significant” shrinking in the LEFT amygdala, which could be explained by NORMAL asymmetry in the brain. As for the horror show MRI images, I think a sufficient explanation is that they simply cross-sectioned a lower part of the unexposed brain where development was particularly lopsided.

David,

what concerns me is the big block of missing tissue at about 4-O’Clock on the MRI scan of the control subject. What is up with that?!?