Teller et al (1986)
some researchers have argued that we need to move away from this type
of measure of acuity and consider 'hyper' or 'Vernier' acuity
requiring, they argue, slightly higher cognitive ability. Even so
there are other problems with the use of FP.
For the Technically
Minded: In the early days of using FP, researchers would often
follow an operant conditioning paradigm. Psychologists have spent
many years perfecting techniques of operant conditioning. When
incorporated within clinical settings using operant procedures, FP
often produced peculiar results. For instance, one of the authors
once witnessed the following scene. An infant was brought into a lab
and confronted with a large apparatus. Gratings versus grey squares
were presented and if the child looked to the correct stimulus, a
rabbit popped up, played a dance and beat a drum. Meanwhile the
experimenter lurked behind the apparatus, occasionally popping up
when he should have stayed down. The result was the child's
conditioning took place, but not to the 'gratings then rabbit'.
Instead it took place to the "grey square then laughing
experimenter'. The child was diagnosed as blind, which only goes to
prove that there are none so blind as those who will not see!