title: More complex brains are not always better: rats outperform humans in implicit category-based generalization by implementing a similarity-based strategy.
abstract: Generalization from previous experiences to new situations is a hallmark of intelligent behavior and a prerequisite for category learning. It has been proposed that category learning in humans relies on multiple brain systems that compete with each other, including an explicit, rule-based system and an implicit system. Given that humans are biased to follow rule-based strategies, a counterintuitive prediction of this model is that other animals, in which this rule-based system is less developed, might generalize better to new stimuli in implicit category-learning tasks that are not rule-based. To test this prediction, rats and humans were trained in rule-based and information-integration category-learning tasks with visual stimuli. The generalization performance of rats and humans was equal in rule-based categorization, but rats outperformed humans on generalization in the information-integration task. The performance of rats was consistent with a nondimensional, similarity-based categorization strategy. These findings illustrate through a comparative approach that the bias toward rule-based strategies can impede humans' performance on generalization tasks.
authors.affiliation: Laboratory of Biological Psychology, University of Leuven (KU Leuven), Tiensestraat 102, B3000, Leuven, Belgium, ben.vermaercke@ppw.kuleuven.be.
authors.forename: Ben
authors.initials: B
authors.lastname: Vermaercke
authors.forename: Elsy
authors.initials: E
authors.lastname: Cop
authors.forename: Sam
authors.initials: S
authors.lastname: Willems
authors.forename: Rudi
authors.initials: R
authors.lastname: D'Hooge
authors.forename: Hans P
authors.initials: HP
authors.lastname: Op de Beeck
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D005793:Generalization, Psychological / Q000502:physiology*; D006801:Humans; D018782:Maze Learning / Q000502:physiology; D011597:Psychomotor Performance / Q000502:physiology*; D051381:Rats; D014796:Visual Perception / Q000502:physiology; D055815:Young Adult