The Role of Linguistic Labels in Infants' Categorization: An Eye Tracking Study

The Role of Linguistic Labels in Infants' Categorization: An Eye Tracking Study Wei (Sophia) Deng (deng.69@osu.edu) Department of Psychology and Center for Cognitive Science The Ohio State University 209C Ohio Stadium East, 1961 Tuttle Park Place Columbus, OH 43210 USA Vladimir M. Sloutsky (sloutsky.1@osu.edu) Department of Psychology and Center for Cognitive Science The Ohio State University 208C Ohio Stadium East, 1961 Tuttle Park Place Columbus, OH 43210 USA Abstract denote categories and “infants embark on the task of word learning equipped with a broad, universally shared expectation, linking words to commonalities among objects” (Waxman, 2003). According to this view, linguistic labels refer to category information and facilitate infants’ category learning. There is much evidence consistent with this view. First, some researchers have demonstrated that labels may facilitate infants’ categorization above and beyond other kinds of auditory input (Balaban & Waxman, 1997; Fulkerson & Haaf, 2003; Fulkerson et al., 2006; Ferry, Hespos, & Waxman, 2010). Second, facilitative effects of linguistic labels were demonstrated for basic-level as well as superordinate or global categories (Balaban & Waxman, 1997; Waxman & Markow, 1995; Waxman & Booth, 2003). Finally, effects of labels have been shown to affect infants’ performance on a variety of cognitive tasks, such as inductive inference (Graham, Kilbreath, Welder, 2004; Welder & Graham, 2001) and object individuation (Xu, 2002; Xu, Cote, & Baker, 2005). There are challenges, however, to the idea that linguistic labels are category markers that facilitate categorization early in development. There are theoretical proposals arguing that, at least early in development, labels are features of items (similar to color or shape) rather than category markers (Sloutsky & Lo, 1999; Sloutsky & Fisher, 2004; Sloutsky, Lo, & Fisher, 2001) and the contribution of linguistic labels is driven by attentional rather than conceptual factors (Napolitano & Sloutsky, 2004; Sloutsky & Napolitano 2003). There is also evidence that auditory input overshadows (or attenuates processing of) corresponding visual input (Lewkowicz, 1988a, 1988b; Napolitano & Sloutsky, 2004; Robinson et al., 2005; Robinson & Sloutsky, 2004a, 2004b; Sloutsky & Napolitano, 2003). Furthermore, many of the studies examining the effects of labels on infants’ category learning compared the effects of labels with those of unfamiliar sounds, but not with a silent condition. When a salient baseline was introduced (e.g., Robinson & Sloutsky, 2007), labels did not facilitate infants’ category learning above the How do words affect categorization? According to one theoretical account, even early in development, labels are category markers and are different from other features. According to another theory, early in development, labels are part of the input and are no more than other features. The current study addressed this issue by examining the effects of labels on category learning in 8- to 12- month infants. Infants were familiarized with exemplars from one category in either label-defined or motion-defined condition and then tested with prototypes from learned category and novel category. Eye tracking results indicated that infants exhibited better category learning in the motion-defined than in the label- defined condition. These results provide little evidence for the idea that labels are category markers that facilitate category learning. Keywords: Cognitive Development, Categorization, Attention, Label, Psychology, Human Experimentation. Introduction The ability to form categories is an important component of human cognition (see Murphy, 2002, for a review). It has been well established that this ability appears early in development, with young infants capable of forming categories at an early age (Eimas & Quinn, 1994; Oakes, Madole, & Cohen, 1991), and a substantial body of experimental evidence suggest that linguistic labels affect this process (Balaban & Waxman, 1997; Waxman & Markow, 1995; Fulkerson, Waxman, & Seymour, 2006; Waxman & Booth 2003; Robinson & Sloutsky, 2007). However, the mechanisms underlying the role of labels remain unclear, which has generated considerable debate. Some have argued that words denoting categories have the special status of category markers and, as such, they facilitate category learning at the earliest stages of word learning. At the same time, others have argued that early in development words are akin to other features, but they may become category markers in the course of development. According to the former theory, early in development, young infants have general assumptions that words but not other kinds of auditory inputs are category markers which