Functional Neuroanatomy of Criterion Attribute and Family Resemblance Category Learning

Abstract:
Subsystems of category learning have been identified on the basis of general domains of content (e.g., tools, faces). The present study examined categories from the standpoint of internal structure and determined brain topography associated with acquiring two fundamentally different category structures (criterion attribute, CA, and family resemblance, FR). CA category learning involves processing stimuli by isolated features and classifying by properties held by all members. FR learning involves processing stimuli by integral wholes and classifying on overall similarity among members without sharing identical features. fMRI BOLD response to CA and FR categorization was measured with pseudowords as stimuli. Category knowledge for both tasks was mastered prior to brain imaging. Areas of activation emerged unique to the structure of each category that followed from the nature of the rule abstraction procedure. Data indicated anterior temporal structures help attune visual processing procedures to high frequency components and the discrimination of features to support criterial, predictive rules. Extrastriate cortex is used when low frequency, multi-featural information is crucial to rule abstraction. Categorization based upon differently structured information does produce distinct brain representations even when it emerges from the same class of stimulus material.