Implicit and explicit category learning by macaques (Macaca mulatta) and humans (Homo sapiens)

TitleImplicit and explicit category learning by macaques (Macaca mulatta) and humans (Homo sapiens)
Publication TypeJournal Article
Year of Publication2010
AuthorsJ Smith, D., Beran M. J., Crossley M. J., Boomer J., & F Ashby G.
JournalJournal of Experimental Psychology: Animal Behavior Processes
Date Published2010 Jan
KeywordsAdolescent, Animals, Association Learning, Discrimination Learning, Female, Humans, Macaca mulatta, Male, Models, Psychological, Orientation, Pattern Recognition, Visual, Photic Stimulation, Reaction Time, Task Performance and Analysis, Young Adult

An influential theoretical perspective differentiates in humans an explicit, rule-based system of category learning from an implicit system that slowly associates different regions of perceptual space with different response outputs. This perspective was extended for the 1st time to the category learning of nonhuman primates. Humans (Homo sapiens) and macaques (Macaca mulatta) learned categories composed of sine-wave gratings that varied across trials in bar width and bar orientation. The categories had either a single-dimensional, rule-based solution or a two-dimensional, information-integration solution. Humans strongly dimensionalized the stimuli and learned the rule-based task far more quickly. Six macaques showed the same performance advantage in the rule-based task. In humans, rule-based category learning is linked to explicit cognition, consciousness, and declarative reports about the contents of cognition. These results demonstrate an empirical continuity between human and nonhuman primate cognition, suggesting that nonhuman primates may have some structural components of humans' capacity for explicit cognition.

Alternate JournalJ Exp Psychol Anim Behav Process
PubMed ID20141317
PubMed Central IDPMC2841782
Grant ListP01 HD038051 / HD / NICHD NIH HHS / United States
P01 HD038051-060006 / HD / NICHD NIH HHS / United States
HD-38051 / HD / NICHD NIH HHS / United States
R01 MH3760-2 / MH / NIMH NIH HHS / United States