title: Learning mode and exemplar sequencing in unsupervised category learning.
abstract: Exemplar sequencing effects in incidental and intentional unsupervised category learning were investigated to illuminate how people form categories without an external teacher. Stimuli were perfectly separable into 2 categories based on 1 of 2 dimensions of variation. Sequencing of the first 20 training stimuli was manipulated. In the blocked condition, 10 Category A stimuli were followed by 10 Category B stimuli. In the intermixed condition, these 20 stimuli were ordered randomly. Experiment 1 revealed an interaction between learning mode and sequence, with better intentional learning for intermixed sequences but better incidental learning for blocked sequences. Experiment 2 showed that manipulating trial-to-trial variability along each dimension can impact intentional learning. Training sequences that emphasized variation along the category-relevant dimension resulted in better performance than sequences that emphasized variation along the category-irrelevant dimension. The results suggest that unsupervised category learning is influenced by the mode of learning and the order and nature of encountered exemplars.
authors.affiliation: Department of Psychology, University of Texas.
authors.forename: Dagmar
authors.initials: D
authors.lastname: Zeithamova
authors.affiliation: Department of Psychology, University of Texas.
authors.forename: W Todd
authors.initials: WT
authors.lastname: Maddox
mesh_terms: D001245:Association Learning; D001288:Attention; D003210:Concept Formation; D004193:Discrimination Learning; D005246:Feedback; D006801:Humans; D033182:Intention; D011939:Mental Recall; D009949:Orientation; D010364:Pattern Recognition, Visual; D011340:Problem Solving; D011930:Reaction Time