Summary: Anticipatory Eye Movements Reveal
Infants' Auditory and Visual Categories
Bob McMurray and Richard N. Aslin
Department of Brain and Cognitive Sciences
University of Rochester
We introduce a new paradigm for the assessment of auditory and visual categories in
6-month-old infants using a 2-alternative anticipatory eye-movement response. In-
fants were trained by 2 different methods to anticipate the location of a visual rein-
forcer at 1 of 2 spatial locations (right or left) based on the identity of 2 cuing stimuli.
After a training phase, infants were presented with a series of generalization trials in
which novel (untrained) stimuli served as the cue to the anticipatory eye movement.
Four experiments illustrated that infants can learn the 2-choice discriminative re-
sponse during training. Infants also showed anticipatory eye movements to novel
stimuli, indicating sensitivity to variations along a variety of stimulus dimensions
(e.g., color, shape, orientation, spatial frequency, pitch, and duration). In addition, the
paradigm can be used to assess categorization in individual infants, thereby revealing
the stimulus dimensions to which infants naturally attend.
One of the most important cognitive skills acquired during infancy is categoriza-
tion, the ability to group together on some basis (e.g., perceptual or functional) a
set of exemplars that are easily discriminated from each other. The study of infants'