Linguistic cued attention in children: Words organize attention to shape in a visual search task

Linguistic cued attention in children: Words organize attention to shape in a visual search task Catarina Vales (cvales@indiana.edu) Department of Psychological and Brain Sciences, 1101 E 10 th St Bloomington, IN 47405 USA Linda B. Smith (smith4@indiana.edu) Department of Psychological and Brain Sciences, 1101 E 10 th St Bloomington, IN 47405 USA Abstract By one account of early word learning, children become proficient word learners as a result of environmental regularities: Learning words tunes the child to the regularities offered by the language being learned, orienting attention to those regularities. We test one core claim of this account, that count nouns should cue attention to the shape of the objects. Using a visual search task we present evidence that hearing the name of the object narrows children’s attention to the objects in the array that have the same shape. Future steps and the implications of these results are discussed. Keywords: attention; language and cognition; visual search; word learning. Introduction Using past experience to select what to attend to is a powerful feature of human cognition. If exposed to environmental regularities, infants (Kirkham, Slemmer and Johnson, 2002; Saffran, Aslin & Newport, 1996) and adults (Chun & Jiang, 1998; Zhao, Ngo, McKendrick, & Turk- Browne, 2011) readily attend to the current events that better match the underlying structure of their previous experience. This ability to selectively attend to the most reliable sources of information as a result of past experience has been proposed as a mechanism underlying early word learning. Not only do children learn a large amount of words in the first years of life, but they also seem to do so in very smart ways. For example, by 2.5 years children use shape to generalize new noun categories – if given a novel named object, children will selectively attend to shape over color or texture when extending the novel name to new exemplars (the shape bias; Booth & Waxman, 2002; Jones & Smith, 2002). Because in English many count nouns map to object categories well organized by within-category shape similarity, learning individual word-object mappings could create a top-down process that would organize future learning. According to the attentional learning account of the shape bias, it is the co-occurrence of nouns and shapes that creates an attentional bias to shape over other features when generalizing a new object category. Although there is evidence supporting the attentional account (Gershkoff- Stowe & Smith, 2004; Jones, 2003; Smith, Jones, Landau, Gershkoff-Stowe, & Samuelson, 2002), the specific mechanisms through which nouns cue object shape have not been directly tested. In the traditional shape bias task, children are asked to generalize a new object category in an untimed forced-choice procedure. The fact that children tend to select the shape match could be do to attentional processes or to much later decision processes. Indeed, competing theories of the attentional learning account have suggested that the shape bias reflects more conceptual theories about how words refer to objects (Waxman & Gelman, 2009). The purpose of this paper is to empirically test a core claim of the selective attention account: That words cue children’s attention to the shape of the objects. To this end, we use a visual search task – a well-documented attentional task in which participants are asked to find a particular object (the target) amidst distractor objects. In the visual search literature with adults (Treisman & Gelade, 1980) and children (Gerhardstein & Rovee-Collier, 2002), when the target and the distractors differ by just one feature, search is almost effortless and does not depend on the number of distractors. When the target and the distractors have overlapping features, finding the target becomes a serial search – and response times depend on the number of distractors. The intercept and the slope of the search function are also indicators of the attentional processes involved. While the slope reflects the per item search time (i.e. how long it takes per item to decide if it is the target), the intercept is thought to reflect pre-search processes, including the representation of the search target in working memory (Vickery, King & Jiang, 2005; Woodman, Vogel and & Luck, 2001). To investigate the role of labels in visual attention we use a visual search task to compare children’s performance when they were cued with both the spoken name and a picture of the target versus then they were cued with just a picture of the target. Experiment 1: Do labels cue attention to shape? Finding a target requires keeping a representation of the target in working memory. Research with adults has suggested that more robust working memory representations of the target result in overall decrease in search times (i.e. intercept changes). Because visual attention is biased