If you have got this far, you should have looked at a display of an
English sentence which you have
probably encountered previously.
The display should have been shut before you came here, so that you can no longer see the words.
If you saw something wrong when you first looked at the display, you
are not a suitable subject for
the experiment.
However, a significant subset of those who look at the display see
nothing wrong with it, even if asked
to check carefully, and even if they know that other people looking
at the display do see something wrong.
Some of those who thought there was nothing wrong change their mind
if later given one of these two
tasks with the display out of sight:
If you saw the superfluous word when you first looked, or if you
failed to see it
when looking at the display, and continued not to be aware of
anything wrong
even when you considered the two questions, then the experiment has
failed for you.
It works for between 1/3 and 2/3 of the people I have tried
it on, e.g. when presenting a seminar
on vision.
I have not attempted to find any other differences linked to
this capability.
If you did not see anything wrong with the display, please look back
at it now, to see
what you did not notice previously: here.
Added: 30 Apr 2012
The following presentation on the functions of vision
is relevant:
http://www.cs.bham.ac.uk/research/projects/cogaff/talks/#gibson
What's vision for, and how does it work?
From Marr (and earlier) to Gibson and Beyond
Maintained by
Aaron Sloman
School of Computer Science
The University of Birmingham