| |
Abstract:
In previous investigations, we have shown category-specific
effects in an episodic learning task that are quantitatively and
qualitatively similar to those observed in patients with
category-specific agnosia.. In the present study, using a similar
learning paradigm, we examined the relationship between the visual
similarity of objects (defined in terms of their overlap along
specific perceptual dimensions) and their conceptual similarity. We
first trained participants to associate conceptual labels to novel
forms. Labels were either semantically related or unrelated, and
stimuli were either visually similar or dissimilar. Participants
were trained so that they were equally adept at recalling the
labels for all conditions. We then utilized a color-training
paradigm in which colored objects were presented pair-wise for a
limited duration, followed immediately by the previously learned
label of one of the objects. Participants were required to report
the color of the cued object as quickly as possible, via the
acquired label for that object. Unknown to participants, objects
were consistently colored in this phase. After several
color-training blocks, participants were given a surprise recall
test requiring them to report the color of each object. Since each
object was associated with a meaningful concept, recall of color
would include both perceptual and semantic diagnostic features. We
report the effect of category structure and perceptual overlap from
the observed color confusion matrix.
|
