Auditory Dominance: Overshadowing or Response Competition?

Auditory Dominance: Overshadowing or Response Competition? 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 208C Ohio Stadium East, 1961 Tuttle Park Place Columbus, OH 43210, USA 2004; Robinson & Sloutsky, 2004; in press-a; in press-b; Sloutsky & Napolitano, 2003). Second, there is an auditory dominance effect: While the presence of an auditory stimulus often hinders visual discrimination, the presence of a visual stimulus often has little or no effect on auditory discrimination (Sloutsky & Robinson, in press). Third, auditory dominance decreases in the course of development (Robinson & Sloutsky, 2004; Sloutsky & Napolitano, 2003). Fourth, auditory dominance can be reversed or attenuated by manipulating the familiarity of the auditory and visual stimuli (Napolitano & Sloutsky, 2004; Robinson & Sloutsky, in press-a; Sloutsky & Robinson, in press). Finally, while unfamiliar sounds and words often have different effects on visual tasks, familiar sounds and words often have comparable effects on visual tasks (Robinson & Sloutsky, in press-a; Sloutsky & Robinson, in press). Although auditory dominance is well documented, the mechanism(s) underlying these effects need further examination. For example, one mechanism that can result in auditory dominance is overshadowing. According to this account, poor visual discrimination in bimodal conditions stems from the auditory stimulus pulling attention away from the visual stimulus and, thus, attenuating the encoding of visual input. However, it is also possible that some of these effects stem from response competition. According to this account, children encode both modalities, however, the auditory input interferes with or is preferred when making a decision or response. The primary goal of the current research is to distinguish between these two possible mechanisms that may underlie auditory dominance. The current study employed a variation of the immediate recognition task recently used by Napolitano and Sloutsky (2004). Children were first presented with a target stimulus, which was followed by a test stimulus. Children were instructed to say Abstract The ability to process simultaneously presented auditory and visual information is a necessary component underlying many cognitive tasks. While this ability is often taken for granted, previous research has demonstrated that there are many occasions where infants and young children are better at discriminating a visual stimulus when it is presented in isolation than when paired with an auditory stimulus. The current study expands on this research by examining whether this attenuated discrimination stems from overshadowing (auditory stimulus disrupts encoding of visual stimulus) or from response competition (auditory input interferes with visual processing during the decision or response phase). While attenuated discrimination in the current study stemmed from response competition, we argue that both overshadowing and response competition underlie auditory dominance effects. Keywords: Cognitive Development, Attention, Language Acquisition, Psychology, Human Experimentation. Introduction The ability to process simultaneously presented auditory and visual information is a necessary component underlying many cognitive tasks. For example, word learning and effects of linguistic labels on categorization, induction and object individuation all hinge on the ability to encode and store arbitrary, auditory-visual pairings (Balaban & Waxman, 1997; Sloutsky & Fisher, 2004; Sloutsky, Lo, & Fisher, 2001; Welder & Graham, 2001; Xu, 2002). The current research can shed light on many different aspects of cognitive development by examining how children process simultaneously presented auditory and visual stimuli more generally. The research that has examined infants’ and young children’s processing of arbitrary auditory-visual pairings has documented several important findings. First, infants and young children are often better at discriminating a visual stimulus when it is presented in isolation than when paired with an auditory stimulus (Napolitano & Sloutsky,