title: A methodological investigation of the Intermodal Preferential Looking paradigm: Methods of analyses, picture selection and data rejection criteria.
abstract: The Intermodal Preferential Looking paradigm provides a sensitive measure of a child's online word comprehension. To complement existing recommendations (Fernald, Zangl, Portillo, & Marchman, 2008), the present study evaluates the impact of experimental noise generated by two aspects of the visual stimuli on the robustness of familiar word recognition with and without mispronunciations: the presence of a central fixation point and the level of visual noise in the pictures (as measured by luminance saliency). Twenty-month-old infants were presented with a classic word recognition IPL procedure in 3 conditions: without a fixation stimulus (No Fixation - noisiest condition), with a fixation stimulus before trial onset (Fixation, intermediate), and with a fixation stimulus, a neutral background and equally salient images (Fixation Plus - least noisy). Data were systematically analyzed considering a range of data selection criteria and dependent variables (proportion of looking time towards the target, longest look, and time-course analysis). Critically, the expected pronunciation and naming interaction was only found in the Fixation Plus condition. We discuss the impact of data selection criteria and the dependent variable choice on the modulation of these effects across the different conditions.
authors.affiliation: Department of Languages and Linguistics, University of Essex, United Kingdom. Electronic address: chdell@essex.ac.uk.
authors.forename: Claire
authors.initials: C
authors.lastname: Delle Luche
authors.affiliation: University of Liverpool, United Kingdom.
authors.forename: Samantha
authors.initials: S
authors.lastname: Durrant
authors.affiliation: Université Paris Descartes, Sorbonne Paris Cité, Paris, France; CNRS, Laboratoire Psychologie de la Perception, UMR 8158, Paris, France.
authors.forename: Silvana
authors.initials: S
authors.lastname: Poltrock
authors.affiliation: Plymouth University, United Kingdom.
authors.forename: Caroline
authors.initials: C
authors.lastname: Floccia
mesh_terms: D000161:Acoustic Stimulation; D032882:Comprehension; D005260:Female; D005403:Fixation, Ocular; D006801:Humans; D007223:Infant; D018730:Infant Behavior / Q000523:psychology*; D007802:Language; D008297:Male; D009622:Noise; D010775:Photic Stimulation; D021641:Recognition, Psychology; D015203:Reproducibility of Results; D012107:Research Design
keywords: Intermodal Preferential Looking; Methodology; Time course analysis; Word recognition