Are the Products of Statistical Learning Abstract or Stimulus-Specific?

Learners can segment potential lexical units from syllable streams when statistically variable transitional probabilities between adjacent syllables are the only cues to word boundaries. Here we examine the nature of the representations that result from statistical learning by assessing learners’ ability to generalize across acoustically different stimuli. In three experiments, we compare two possibilities: that the products of statistical segmentation processes are abstract and generalizable representations, or, alternatively, that products of statistical learning are stimulus-bound and restricted to perceptually similar instances. In Experiment 1, learners segmented units from statistically predictable streams, and recognized these units when they were acoustically transformed by temporal reversals. In Experiment 2, learners were able to segment units from temporally reversed syllable streams, but were only able to generalize in conditions of mild acoustic transformation. In Experiment 3, learners were able to recognize statistically segmented units after a voice change but were unable to do so when the novel voice was mildly distorted. Together these results suggest that representations that result from statistical learning can be abstracted to some degree, but not in all listening conditions

Preschool children's interpretation of others' history of accuracy

Over the past 25 years, there has been tremendous interest in the development of children’s ability to reason about others’ mental states, or “theory of mind”. Much research has explored children's understanding of situational cues that lead to knowledge, but only recently has research begun to assess children's understanding of person-specific differences in knowledge. A number of studies (Birch, Vauthier & Bloom, 2008; Jaswal & Neely, 2006; Koenig, Clément & Harris, 2004) have recently demonstrated that at least by age 3 children pay attention to others' history of accuracy and use it as a cue when deciding from whom to learn. However, the nature and scope of children's interpretations of other's prior accuracy remains unclear. Experiment 1 assessed whether 4- and 5-year-olds interpret prior accuracy as indicative of knowledge, as opposed to two other accounts that do not involve epistemic attributions. This experiment revealed that preschool children can revise their tendency to prefer to learn from a previously accurate informant over an inaccurate one when presented with evidence regarding each informant's current knowledge state. Experiment 2 investigated how broadly a person's history of accuracy influences children's subsequent inferences, and showed that 5-year-olds (but not 4-year-olds) use information about an individual's past accuracy to predict her knowledge in other related domains as well as her propensity for prosocial or antisocial behaviour. Overall, children's performance in these experiments suggests that both 4- and 5-year-olds interpret others' history of accuracy as indicative of knowledge; however, 4-year-olds make a more restricted attribution of knowledge while 5-year-olds make a more stable, trait-like attribution. These findings are discussed in terms of their implications for research on theory of mind and more broadly on children's social and cognitive development.Arts, Faculty ofPsychology, Department ofGraduat

Variations in children's use of individuals' past accuracy

Young children learn an abundance of information about the world from other people. Yet, people sometimes provide inaccurate or questionable information. Hence, when learning from others, it is advantageous to be selective and evaluate the likely accuracy of the information and its source. Previous research has shown that preschool-age children can attend to a variety of cues indicative of others’ knowledge and use those cues to guide their learning. Yet, just because children can use knowledge cues to guide their selective learning does not mean that they do so, or even should do so, in all circumstances. The present research assessed children's understanding of whether these cues predict a person’s future knowledge of different types of information by examining variations in children’s use of an individual's past accuracy depending on the type of information being learned. Experiments 1 to 3 demonstrated that 4-year-olds generalized past accuracy in a savvy way, using it to moderate their learning across different types of objective information but abstaining from generalizing to situations involving subjective information. In contrast, 3-year-olds (Experiments 1-2) used past accuracy narrowly, failing to generalize an individual’s past accuracy in one area of knowledge to situations that involved learning in another area of knowledge. Experiments 4 and 5 investigated whether children ages 4 to 7 understand that past accuracy demonstrated with generalizable, or category-level, information is a useful predictor of other generalizable knowledge but not of idiosyncratic, or instance-specific, knowledge. Children used an individual’s past accuracy to decide whether or not to learn generalizable information from that individual or from a different source, but wisely disregarded past accuracy when learning idiosyncratic information. Experiments 6 and 7 further demonstrated that 4- and 5-year-olds are more likely to use past accuracy when learning generalizable than idiosyncratic information and appropriately use others’ information access to predict their idiosyncratic knowledge. Overall, this research demonstrates that preschool- and early-school-age children possess a nuanced understanding of the predictive value of knowledge cues for different types of knowledge. The implications of these results for children’s developing understanding of the mind and other aspects of social cognition are discussed.Arts, Faculty ofPsychology, Department ofGraduat

Should we always log-transform looking time data in infancy research?

Researchers often measure infants looking time (LT) as a dependent variable to measure how infants pay attention to certainstimuli. Using a large repository of data from their lab and the literature, Csibra and colleagues (2016) reported that thedistribution of LT is positively skewed and thus proposed that researchers should log-transform LT before running anyparametric analysis. In this study, we investigated whether log-transformation of LT will make the distribution normallydistributed by using data from a large-scale replication infancy study (ManyBabies Consortium (MB1), in press). Further,we simulated positively skewed LT data to examine whether log-transformation of LT would improve power. We foundthat log-transformation of the MB1 LT data did not make the LT data normally distributed. Also, we found that log-transformation of LT only slightly increased power. Implications and benefits of log-transformation of LT data will bediscussed

You seem certain but you were wrong before: Developmental change in preschoolers’ relative trust in accurate versus confident speakers

<p>Dataset for Brosseau-Liard, Cassels and Birch, "You seem certain but you were wrong before: Developmental change in preschoolers’ relative trust in accurate versus confident speakers" (PLoS ONE)</p

Simple slopes for predicted propensity to side with the confident individual by age.

<p>Simple slopes for predicted propensity to side with the confident individual by age.</p