Labels for the categories have been found to facilitate learning by boosting accuracy. According to the label-feedback hypothesis, this facilitation is due to a mechanism selectively sensitising perceptual dimensions. To further investigate the label-facilitation phenomenon, one group of participants in our study learned both named and hard-to-name artificial categories, in a novel, within-subjects design. Another group of participants was administered a-highly similar-paired-associate task purportedly not involving sensitization of dimensions. Results showed that labels boosted accuracy during learning, but only when learning to categorise-not when learning to associate. The label-feedback hypothesis posits that labels exert an influence also after new categories have been learned. To test for sustained effects of labels, we administered a post-learning visual discrimination task while monitoring participants' eye movements and analysing dwell time on the trained shapes. There was some indication of sustained effects of labels for newly-learned categories, but there was no effect following learning to associate. Our results suggest that labels for newly learned categories have immediate effects during learning and that the effects of labels may also be sustained during post-learning processing.
Keywords: Verbal labels; category learning; eye tracking; visual attention.