Linguistic labels, dynamic visual features, and attention in infant category learning

Abstract

How do words affect categorization? According to some accounts, even early in development words are category markers and are different from other features. According to other accounts, early in development words are part of the input and are akin to other features. The current study addressed this issue by examining the role of words and dynamic visual features in category learning in 8- to 12-month-old infants. Infants were familiarized with exemplars from one category in a label-defined or motion-defined condition and then tested with prototypes from the studied category and from a novel contrast category. Eye-tracking results indicated that infants exhibited better category learning in the motion-defined condition than in the label-defined condition, and their attention was more distributed among different features when there was a dynamic visual feature compared with the label-defined condition. These results provide little evidence for the idea that linguistic labels are category markers that facilitate category learning.

Keywords: Attention; Category learning; Cognitive development; Dynamic visual cues; Eye-tracking; Infancy; Labeling.

Figure 1

Example Stimuli. A. Prototypes of stimuli from Categories A and B; B. Procedures used in this study. C. Areas of interest (AOIs) shown as gray ellipses.

Figure 2

Average looking time on the first-three and last-three familiarization trials in the label-defined and motion-defined conditions.

Figure 3

Novelty preference scores on first two test trials and second two test trials in the label-defined and motion-defined conditions.

Figure 4

Individual novelty preference scores in the label-defined and motion-defined conditions in Blocks 1–2 (A) and in blocks 3–4 (B).

Figure 5

Proportion of accumulated looking time to each feature averaged across 4 blocks at test in the label-defined and motion-defined conditions.

Figure 6

Proportion of accumulated looking time to each feature averaged across 4 blocks at familiarization in the label-defined and motion-defined conditions.

Figure 7

Average number of valid fixation shifts within each block during familiarization in the label-defined and motion-defined conditions.

Figure 8

Average number of valid fixation shifts averaged across four blocks at each time point within familiarization trials in the label-defined and motion-defined conditions. Each time point represents a 1000 ms time window.

Figure 9

Proportion of accumulated looking time to each feature averaged across 4 blocks at familiarization (A) and test (B) in Experiment 2.