The cat among the pigeons: categorical pop-out in infant visual attention.

In order to assess whether infant attention would be directed towards a visual stimulus that was categorically at odds with surrounding stimuli, 16 infants (mean age = 39 weeks) were presented with 5 displays, each comprising a pair of categorically related items (2 birds) and a pair of unrelated items (bird and cat). The infants displayed earlier and longer fixation to the latter pair, with primary response to the discrepant item in this pair (the cat). Three preliminary experiments with 30 infants (mean age = 38 weeks) discounted a priori preferences for the cat as an explanation of these results, and confirmed that infants were able to discern the categorical similarity amongst the bird items, while also being able to discriminate these items