| dc.description.abstract | After the direct training of baseline conditional relations, the emergence of derived relations that have the properties of reflexivity, symmetry and transitivity documents the formation of
equivalence classes. Studies on the formation of these equivalence classes have shown that the
probability of class formation is influenced by a wide array of variables. The meaningfulness of
the stimuli used has been found to be one of such important variables. The formation of
equivalence classes that include meaningless or abstract stimuli only has been found to be less
probable. However, the inclusion of a meaningful stimulus, such as a familiar picture in a set of
other meaningless stimuli can help to convert that set of stimuli into an equivalence class. In five
studies with college students, this thesis has explored the properties of meaningful stimuli that
account for the class enhancement they produce. Study 1 explored how a simple discriminative
function acquired by an abstract stimulus through simultaneous and/or successive discrimination
training enhanced the formation of an equivalence class of which that stimulus was a member. In
two experiments, Study 2 investigated how the order of training, familiar pictures, and abstract
stimuli that acquired discriminative functions influenced equivalence class formation. In yet
another two experiments, Study 3 studied the effect of the use of a meaningful stimulus as a class
member on equivalence class formation. Two parallel groups were trained to form three 3-node
5-member equivalence classes (A B C D E) under the simultaneous protocol in both
experiments. The baseline relations AB, BC, CD, and DE were trained in a serialized manner in
Experiment 1 while Experiment 2 involved the concurrent training of baseline relations. Study 4
investigated whether the acquisition of an identity conditional discriminative function by a
meaningless stimulus using simultaneous or delayed matching procedures would influence the
likelihood of formation of an equivalence class of which it is a member along with other
meaningless stimuli. In a replication to Study 4, Study 5 investigated how equivalence class
formation was enhanced by the inclusion of one abstract stimulus that had acquired an identity or
arbitrary conditional discriminative function on a simultaneous or delayed basis, prior to the
establishment of the classes. In addition to their traditional connotative and denotative properties,
these studies extend our knowledge on the class enhancing properties of meaningful stimuli to
include acquired discriminative functions and delayed relational (identity and arbitrary)
functions. The studies also strengthen existing findings that the inclusion of a meaningful
stimulus in a set of other meaningless class enhances the formation of equivalence classes.
However, its inclusion alone is shown to be insufficient to generate the class enhancement and
that, the order of introduction in the serial training of the baseline relations for a class, the
structural location of the meaningful stimulus in the training structure as well as its behavioral
functions interact with the meaningful stimulus to account for their class enhancement. Finally,
there was a strong concordance between two trial formats: matching to sample trials during class
formation and sorting during post class formation sorting test in terms of participants’
performances indicative of equivalence class formation. | en_US |
