Results – effects of having a target named Comparing known & unknown targets (“name” condition)

1. What are they looking at? Techniques in Preferential Looking Katie Alcock and Sarah Watts Department of Psychology, Lancaster University and Department of Psychology, City University, London k.j.alcock@lancaster.ac.uk • Parent manipulation • Blind/deaf condition • Parents wear sleep mask and hear music over headphones • See/hear condition • Parents can see and hear • Participants • 22 children aged 17-19 months, 9F, 13M • Recruited through nurseries in North London • Results - baseline - looking before sound file ends • Main effect of side • (F 6.68, p = .017, 2 = .24) • No other main effects or interactions • Results - looking time after sound: main effects • Children look more at known words • (F1,21 =17.56, p <.001, η2 =.46) • Children look more at target words • (F1,21 = 35.10, p <.001, η2 =.63) • Children look more to the right • (F1,21 = 4.81, p =.040, η2 =.19) • Results - looking time after sound: interactions • Interaction between parent condition, known, and target: • (F1,21 = 5.30, p =.032, η2 =.20) • When parent can see/hear • classic pattern of more looking at target for both known & unknown targets • When parent can’t see/hear • in unknown target condition no difference between target (unknown) and non-target (known) Effect of parent looking/speaking/pointing? • 10 parents: parent behaviour videoed and scored • Parents all did something • either looked, pointed, or spoke at some point during testing • Group really too small for analysis • But some interactions • Assumptions in preferential looking • Parent interference affects results vs • No response from parent will disturb child • Children will look at target if they can distinguish it from non-target • Scoring issues? - which looks to score • Novel-name nameless-category principle (Golinkoff) • But Schafer, Plunkett & Harris (1999) • Standard preferential looking • Did not name words • More looking at pictures referring to words the child knew • ?Looking depends on knowledge, not on use of input as referent/instruction • Study 1 - Parental looking • Basic preferential looking paradigm • Two pictures • “Look! Look at the X” • Children’s knowledge of a 75-item word list assessed • Balanced known/unknown words within and across children • Scored start and finish of each look • Total looking after end of sound file • Latency of first look after end of sound file • Number of items • 10-20 depending on children’s vocabulary • “Known target” condition (child knows “apple”) • “Unknown target” (child does not know “bear”) Study 1 - Discussion • Parent interaction is affecting children’s performance • May help to explain N3C principle findings in some studies Study 2 - Naming targets • Same paradigm • Two pictures • Look! Look at the X! (“name” condition) • Look! Look at that! (“look” condition) • Words chosen in same way as study 1 • “Name” condition as Study 1 • Balanced order again • “Look” condition (child knows one of two words) • Participants • 20 children aged 17-19 months, recruited as above (2 children did not complete testing so N = 18) • Results - effects of knowing a word • Collapsing targets/non-targets in “name” condition • In other words comparing: • Known with unknown (regardless of whether they are named or not) • by “name” condition vs “look” condition • Looking time after sound ends: • known (F1,17 = 4.647, p =.046, 2 = .22) • more looking at pictures representing known words • condition (F1,17 = 4.316, p = .053, 2 = .20) • Slightly more looking overall in “name” condition • No effect on latency • No effect on looking before the picture is named • Results – effects of having a target named • Comparing known & unknown targets (“name” condition) • with known & unknown pictures (“look” condition) • In other words comparing • “Default” looking words (targets in “name” condition, known in “look” condition) • by “name” vs “look” • Test of Schafer et al. • Looking after sound • whether word was known (F1,17 = 13.09, p = .002, 2 = .44) • No other effects • including no effect of condition i.e. of hearing the name of the word • (Only effects on latency or looking during sound are of side) • Study 2 - Discussion • Naming of items increases looking time overall • But does not increase looking time to targets • no more than knowing a word increases looking time to its picture, in the absence of a name • Naming increase probably general attentional phenomenon • More variable input! • Conclusions • Children may look at target-known pictures more than non-target or unknown pictures • But may not be because of N3C principle • Simply knowing a word increases looking • N3C seems to apply preferentially when parent is “helping” • Any effect of child’s vocabulary? • References • Golinkoff, R. M., Mervis, C. B., & Hirsh-Pasek, K. (1994). Early object labels: The case for a developmental lexical principles framework. Journal of Child Language, 21(1), 125-155. • Schafer, G., Plunkett, K., & Harris, P. L. (1999). What's in a name? Lexical knowledge drives infants' visual preferences in the absence of referential input. Developmental Science, 2(2), 187.