The model of classical conditioning introduced by Balkenius is anaylzed with varying.
They show that the learning converges under stable stimulus.
sequences and further investigate how the asymptotic CR amptitude depends on CS and US .
magnitude and timing the basis for the model is the view that the goal of classical conditioning.
is to establishi a temporal gradient that represents the distance to the goal event.
Mower's two process theory of phobic aquistion and maintenance seemed to deal with.
the inadquancies of the original contiguity- based classical conditioning model. This proposed.
that the phobia is aquired in the same way as the original model but it is maintained by a process.
of instrumental conditioning, in which the instrumental response, avoidance is negatively .
reinforced by the cessation of anxiety, thus accounting for the phenomenon of incubation. Still .
though, there remains a number of criticisms applicable to Mower's model and the original .
classical conditioning model firstly, not everyone with phobia reports an aversive conditioning .
experience that brought the phobia on. A second criticism concerns the issue of the lack of.
equipotentiality of phobic stimuli. In other words, why is it that animal, height and water phobia.
are so very common when phobias of guns, knives and electrical outlets are unknown, even .
though the second group is the most likely to produce a traumatic outcome. This was explained.
as the phenomenon as being due to "biological preparedness." This is a theory which states.
that humans are genetically predisposed to learn to fear objects and situations that have .
threatened the survival of the species throughout it's evolutionary history. This theory neatly .
explains the wide occurence of spider and snake phobias, since throughout the history of man.
their bites have proved to be fatally dangerous and their avoidance would therefore be advan-.
tageous and explainable in terms of the evolutionary process of natural selection.
