Heads you win, tails you lose: evidence for young infants categorizing mammals by head and facial attributes

Abstract

Four experiments were conducted with infant and adult subjects in an effort to determine the perceptual cues that are used to categorically differentiate between two common animal species, cats and dogs. The stimuli were photographic exemplars of cats, dogs and cat–dog hybrids (i.e. cat head attached to dog body and dog head attached to cat body). Experiments 1 and 2 utilized the familiarization/novelty‐preference procedure and showed that 4‐month‐old infants relied on head/face information to categorically differentiate between cats and dogs under conditions of short exposure duration. Experiments 3 and 4 showed that adult subjects also focus on head/face information in typicality ratings and forced‐choice identifications of category membership. However, results from reaction times with adults suggest that the type of information that becomes dominant may change with both development and task demands. ©1997 John Wiley & Sons, Ltd.

Perceptual Categorization of Cat and Dog Silhouettes by 3- to 4-Month-Old Infants

“…In sum, there was evidence for categorization of the silhouettes of cats and dogs into separate representations, even though the stimuli lacked internal facial features, which are sufficient cues for categorization (Quinn & Eimas, 1996a;Spencer et al, 1997), and the animals' typical variation in coloring. Despite this result, to conclude that categorization has occurred is premature.…”

“…The importance of the face and head region was corroborated in a study in which infants familiarized with cats or dogs preferred a hybrid animal consisting of a novel category head and familiar category body over a hybrid animal consisting of a novel category body and familiar category head (Spencer et al, 1997). Also consistent with the empirical findings indicating that the head and face region is critical for young infants' categorical differentiation of cats and dogs are simulation results from simple neural networks that failed to learn individuated representations for cats and dogs when provided with inputs reflecting only the bodily attributes (and not the head and face features) of the animal stimuli .…”

“…The findings parallel evidence obtained with young infants performing with the actual head and body photographs of the cat and dog stimuli (Quinn & Eimas, 1996a;Spencer et al, 1997). It is interesting to comment on the possible processing systems that could accommodate these data.…”

Reconceptualizing inhibition of return as

“…This characterization is consistent with the way in which the developmental literature has exploited habituation to examine infant categorization (Cohen, 2004). Developmental studies of infant categorization often habituate infants by repeatedly presenting objects from a category of stimuli, such as cats (Spencer, Quinn, Johnson, & Karmiloff-Smith, 1997) or animate objects (Legerstee, 1992), using exemplars that vary tremendously in their physical representations. In these experiments, habituation is based on the repetition of a concept or category, rather than on the perceptual attributes of the stimuli.…”

Four-Month-Old Infants’ Categorization of Animals: Does Any Body Part Hold Privileged Status?

“…For example, length of trials has been found to influence infants' use of body information (Spencer, Quinn, Johnson, & Karmiloff-Smith, 1997) in categorization. We speculate that when given little time to process an object, the part of the object that most defines the category may be the part to which one first directs attention.…”