On Thu, 22 Nov 2007 23:02:19 -0700, Shearon, Tim wrote:
> Mike- It is hard to tell but I think Moulton and Kosslyn are 
> a bit tongue in cheek here. 

Given the costs involved in doing this kind of research, either
M&K have a very expensive sense of humor or the local fMRI
has too much unscheduled time on its hands.  Then again, someone
might thought that this was a good idea.

>Stephen is usually pretty knowledgeable in the vagaries of 
>science- clearly this study affirms a null hypothesis. 

For psychologists, this might be a problem but not for the
more broadly experienced in statistical matters.  The concept
of "bioequivalence testing" is used to show that two drugs have
the same properties.  The FDA requires this in order to show
that a generic preparation is equivalent to a brand name drug
prep.  A starting point for this topic is provided by wikipedia:
http://en.wikipedia.org/wiki/Bioequivalence
A search of pubmed will provide more technical articles.
Alternatively, one can use the "nil hypothesis" approach,
that is, the difference between two treatments is so small
that it is negligible for high levels of statistical power.

To tell the truth, though, I haven't gone through the article
systematically to determine if they were using a bioequivalence
strategy or if they had a very high level of statistical power.

>But, those who wish to believe will see nothing here 
>as clearly Psi was there but a) wasn't apparent due 
>to the presence of non-believers, b) was apparent to 
>all but the non-believing researchers, c) is too subtle 
>to be measured by fMRI (probably resonates as some 
>other frequency). Sigh. 

First, I think, one needs to ask the question of whether the
believers in Psi believe in science.  This will divide this group
into two:  (a)  Psi believers who do not believe in science
and (b) Psi believers who believe in science or at least
pay lip service to it (this is comparable to the folks who
promote intelligent design:  some simply believe in the truth
of the Bible and don't care about science while others
realize that a scientific facade has to be maintained in order
to achieve certain goals such as teaching ID in the public
schools).

Scientific evidence against Psi, I believe, will be ignored by
those in (a) above while those in (b) might attempt to counter
the scientific evidence in the terms you've specified above.
The real question is what effect these findings will have on
people who are on the fence, neither believers or skeptics.
How will they tip?

>Dis-proving is not a scientific endeavor (and I'm sure the 
>authors know that). 

Not impossible but certainly difficult.  The general strategy is to
show that the probability of the event is exceedingly small.
Evidence like that presented by M&K shows an absence of a
difference, suggesting that at least the expected brain processes
do not support the assertion of existence of Psi.  As this type
of negative evidence increases, the likelihood of the assertion
that Psi exist is reduced.  If there is no replicable evidence of Psi,
then.....

>On the other hand, I think it equally likely they know that 
>you have about the same chance of dissuading a believer.  
>Makes me wonder a little what they were really up to. :)

Some possibilities are:

(1) Regardless of who listens/reads, it's necessary to get the result
on the record.  I believe that Kurt Vonnegut had some words on
the importance of doing this in his novel "Player Piano" in the context
of the "Ghost Shirt" rebellion.

(2) It's another line on the vita.  

(3)  Maybe a news service will pick it up and will give some fraction
of that 15 minutes of fame.

(4)  If they were having problems filling up the time slots for the fMRI
use, at least this research made use of it and it got published.  One 
wonders how many studies using fMRI don't published. :-)

-Mike Palij
New York University
[EMAIL PROTECTED]




---

Reply via email to