The Effect of Labels on Visual Attention: An Eye Tracking Study

The Effect of Labels on Visual Attention: An Eye Tracking Study Catherine A. Best (best.140@osu.edu) Center for Cognitive Science, The Ohio State University 208G Ohio Stadium East, 1961 Tuttle Park Place, Columbus, OH 43210, USA Christopher W. Robinson (robinson.777@osu.edu) Center for Cognitive Science, The Ohio State University 208F Ohio Stadium East, 1961 Tuttle Park Place, Columbus, OH 43210, USA Vladimir M. Sloutsky (sloutsky.1@osu.edu) Center for Cognitive Science, The Ohio State University 208D Ohio Stadium East, 1961 Tuttle Park Place, Columbus, OH 43210, USA Abstract The effects of language on categorization are well documented; however, underlying mechanisms are under debate. According to one account, words facilitate categorization by highlighting commonalities among labeled objects. Although there is some behavioral evidence consistent with this claim, research remains limited for whether labels can direct infants’ attention to corresponding visual features. In the current study, adults and infants were presented with 10 different exemplars that were either associated with 10 different labels, the same label, or presented in silence. An eye tracker recorded visual fixations to common and unique features throughout familiarization. Experiments 1 and 2 provide evidence that unique labels can direct infants’ and adults’ attention to unique features (compared to a silent condition); however, the effect of hearing the same label associated with different objects was less robust in both age groups. Keywords: Attention; Language; Categorization Introduction Beginning at birth, infants must learn to make sense of the world, and the ability to form categories is an important part of this learning. Although very young infants can quickly learn visual categories (Bomba & Siqueland, 1983; Eimas & Quinn, 1994), there is some evidence that words and other types of sounds influence this process. For example, young infants are often better at learning visual categories when category members are associated with the same word than when the same visual stimuli are paired with a nonlinguistic sound (Balaban & Waxman, 1997; Fulkerson & Waxman, 2007; Robinson & Sloutsky, 2007). Exposure to words may also help infants individuate objects. Research demonstrates that infants who hear two different words (but not two sounds) expect two objects to be hidden by an occluder (Xu, 2002). Labels also influence what category structure infants learn. For instance, while looking at the same visual images, infants who heard one word associated with all exemplars learned one category; whereas, infants who heard two words learned two categories (Plunkett, Hu & Cohen, 2008). Finally, although words and sounds often have different effects on categorization and individuation, only a few studies have directly compared infants’ performance in label and sound conditions to a silent baseline. These comparisons illustrate that compared to a silent condition, words and sounds can interfere with categorization of visual input, often with greater interference from sounds than from words (Robinson & Sloutsky, 2007; 2008). To account for the effect of labels on category learning, several mechanisms have been put forth. First, Waxman and colleagues argue that infants understand the conceptual importance of words and that words (but not sounds) facilitate categorization by highlighting the commonalities among labeled entities (Fulkerson & Waxman, 2007; Waxman, 2003). Given the findings reported by Plunkett et al. (2008) and Xu (2002), it is also possible that unique words may also facilitate the formation of multiple categories by highlighting unique features among labeled entities. In contrast, Sloutsky and colleagues argue that infants and young children have difficulty processing multimodal information, with words and sounds often attenuating visual processing (Robinson & Sloutsky, 2004; Sloutsky & Napolitano, 2003). Differential effects of words and sounds stem from sounds interfering with visual tasks more than words (as opposed to words facilitating categorization above a silent control). Thus, according to Waxman and colleagues, hearing common and unique words should increase attention to common and unique features in the early stages of development. In contrast, according to Sloutsky and colleagues, early in development words should have no facilitative effect above a silent condition and may even interfere with visual processing. The aim of the current set of studies was to explore how words might affect visual attention by utilizing eye-tracking technology. Measuring eye movements during experimental tasks provides an online measure of attention. By tracking the gaze of infants and adults during a simple familiarization task, we can investigate whether patterns of visual attention during learning differ with respect to varying language cues. Overview of Current Studies To investigate the effect of labels on visual attention, gaze data were collected from both infants and adults while viewing novel stimuli paired with novel labels. Half the features on each stimulus were shared among the