DePaolis, R. 1 & Keren-Portnoy, T. 2
1 James Madison Univesity
2 University of York
Typically, in a single auditory headturn preference paradigm (AHPP) study either a familiarity or a novelty response at the group level is taken to suggest that the infants have noticed some aspect of the auditory signal. In this presentation we argue that a mix of familiarity and novelty responses can be interpreted together in a single experiment as a coherent group response (see also Aslin, 2000; Dawson & Kidd, 2010). We used the AHPP to record looking times (LT) either to words likely to be familiar to the infants (e.g. baby or nappy) or to words unlikely to be known by any of the infants (e.g. berber or netter). This word form recognition task elicited both familiarity and novelty responses, as well as responses of no-preference, in 59 ten-month-old infants. Independent indices of lexical (CDI) and phonetic (repeated consonant production) advance were also collected. The infants who exhibited an extreme response, whether familiarity or novelty, were more advanced on these indices than the infants who showed no preference (p = .051 for lexical, p = .029 for production indices). Importantly, the groups do not differ on either of two measures that are proxies for general precocity (mean age; speed of processing, as measured by mean total LT). In a trial-by-trial analysis (with infants from the extreme group divided into extreme-novelty and extreme-familiarity), the groups exhibited different trajectories of looking preferences (see Figure 1). An ANOVA revealed an interaction of Time (the six trial pairs) and Group (extreme-novelty, moderate and extreme-familiarity): F[2,56] = 6.392, p < .001, ?2 = .275, supporting the assertion that the groups differ in their responses. We discuss these findings within the framework of the Hunter and Ames (1988) model, which suggests that a familiarity preference is succeded by a novelty preference over time.