From: Damien Broderick (d.broderick@english.unimelb.edu.au)
Date: Wed Nov 03 1999 - 04:56:02 MST
At 11:39 PM 2/11/99 -0000, Bryan Moss wrote:
>> subjects make a
>> detectable GSR `presponse' to visual targets not shown to
>> them until a couple of seconds later. This is a
>> statistical effect, as usual, found in concatenated
>> results
>This is how I'm interpreting the experiment (please correct
>me if I'm wrong): When they saw activity that they
>considered a 'presponse' they put a little tick in the
>'presponse' box, and if they saw no such ativity they put a
>little tick in the 'no presponse' box, and then added them
>all up in the end.
Sorry, I meant `consolidated' not `concatenated' - that is, they combined
the curves gathered over many trials and screened out the random variations
and noise. The composite curves then showed this apparent prodromal effect.
>the only way I can see the data being
>pure is to show only one image to each person, otherwise
>each 'presponse' can be attributed to the previous response.
The details can be found in Radin's paper, which might be accessible at his
web site.
The method, roughly, is to show a series of bland images, to accustom the S
to the task and establish a baseline, then to flash the test image
somewhere randomly between the fourth and tenth images, say. And of course,
there are many Ss, and their runs are consolidated. The aggregated GSR
scores for the test items show a small bur significant surge in advance of
presentation, compared with the background scores for non-target images (I
simplify). Yes, there can then be `Gambler's Fallacy' expectation effects
with confounding consequences, but the experimenters have allowed for this
in their statistical analysis. Obviously, though, this will be the point at
which skepticism will bear down hardest (unless it is assumed from the
outset that the entire endeavour must be bogus - which is why it is
interesting to examine existing data from earlier, non-parapsychological
experiments open to retrospective analysis of such effects.. as is being
done even as we speak).
Damien Broderick
This archive was generated by hypermail 2.1.5 : Fri Nov 01 2002 - 15:05:41 MST