Implicit and explicit categorization: A tale of four species

TitleImplicit and explicit categorization: A tale of four species
Publication TypeJournal Article
Year of Publication2012
AuthorsJ Smith, D., Berg M. E., Cook R. G., Murphy M. S., Crossley M. J., Boomer J., Spiering B., Beran M. J., Church B. A., F Ashby G., & Grace R. C.
JournalNeuroscience and Biobehavioral Reviews
Date Published2012 Nov
KeywordsAnimals, Cognition, Concept Formation, Discrimination Learning, Humans, Judgment, Visual Perception

Categorization is essential for survival, and it is a widely studied cognitive adaptation in humans and animals. An influential neuroscience perspective differentiates in humans an explicit, rule-based categorization system from an implicit system that slowly associates response outputs to different regions of perceptual space. This perspective is being extended to study categorization in other vertebrate species, using category tasks that have a one-dimensional, rule-based solution or a two-dimensional, information-integration solution. Humans, macaques, and capuchin monkeys strongly dimensionalize perceptual stimuli and learn rule-based tasks more quickly. In sharp contrast, pigeons learn these two tasks equally quickly. Pigeons represent a cognitive system in which the commitment to dimensional analysis and category rules was not strongly made. Their results may reveal the character of the ancestral vertebrate categorization system from which that of primates emerged. The primate results establish continuity with human cognition, suggesting that nonhuman primates share aspects of humans' capacity for explicit cognition. The emergence of dimensional analysis and rule learning could have been an important step in primates' cognitive evolution.

Alternate JournalNeurosci Biobehav Rev
PubMed ID22981878
PubMed Central IDPMC3777558
Grant ListP01 HD038051 / HD / NICHD NIH HHS / United States
R01 EY022655 / EY / NEI NIH HHS / United States
P01 NS044393 / NS / NINDS NIH HHS / United States
HD-060563 / HD / NICHD NIH HHS / United States
3P01HD038051-10S1 / HD / NICHD NIH HHS / United States
P01 HD060563 / HD / NICHD NIH HHS / United States