What are they looking at Techniques in Preferential

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 Assumptions in preferential looking n n Parent interference affects results vs No response from parent will disturb child Children will look at target if they can distinguish it from nontarget Scoring issues? - which looks to score n n Participants n n Novel-nameless-category principle (Golinkoff) n But Schafer, Plunkett & Harris (1999) n Standard preferential looking n Did not name words n More looking at pictures referring to words the child knew n ? Looking depends on knowledge, not on use of input as referent/instruction n n Total looking after end of sound file Latency of first look after end of sound file n n 10 -20 depending on children’s vocabulary “Known target” condition (child knows “apple”) n Study 2 - Naming targets Same paradigm Two pictures n Look! Look at the X! (“name” condition) n Look! Look at that! (“look” condition) Words chosen in same way as study 1 “Name” condition as Study 1 Balanced order again n n Main effect of side n (F 6. 68, p =. 017, 2 =. 24) No other main effects or interactions n n n “Look” condition (child knows one of two words) Children look more at known words n (F 1, 21 =17. 56, p <. 001, η 2 =. 46) Children look more at target words n (F 1, 21 = 35. 10, p <. 001, η 2 =. 63) Children look more to the right n (F 1, 21 = 4. 81, p =. 040, η 2 =. 19) 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) n by “name” vs “look” n Test of Schafer et al. n Looking after sound whether word was known (F 1, 17 = 13. 09, p =. 002, 2 =. 44) No other effects n including no effect of condition i. e. of hearing the name of the word n (Only effects on latency or looking during sound are of side) Participants 20 children aged 17 -19 months, recruited as above (2 children did not complete testing so N = 18) n Results - looking time after sound: interactions n Number of items n Parent interaction is affecting children’s performance May help to explain N 3 C principle findings in some studies n Results – effects of having a target named Results - looking time after sound: main effects Study 1 - Parental looking Basic preferential looking paradigm n Two pictures n “Look! Look at the X” n Children’s knowledge of a 75 -item word list assessed n Balanced known/unknown words within and across children n Scored start and finish of each look 22 children aged 17 -19 months, 9 F, 13 M Recruited through nurseries in North London Results - baseline - looking before sound file ends n n Blind/deaf condition n Parents wear sleep mask and hear music over headphones See/hear condition n Parents can see and hear Study 1 - Discussion n n Interaction between parent condition, known, and target: n (F 1, 21 = 5. 30, p =. 032, η 2 =. 20) When parent can see/hear n classic pattern of more looking at target for both known & unknown targets When parent can’t see/hear n in unknown target condition no difference between target (unknown) and non-target (known) Results - effects of knowing a word n n n Collapsing targets/non-targets in “name” condition In other words comparing: n Known with unknown (regardless of whether they are named or not) n by “name” condition vs “look” condition Looking time after sound ends: n known (F 1, 17 = 4. 647, p =. 046, 2 =. 22) n n n n Slightly more looking overall in “name” condition No effect on latency No effect on looking before the picture is named Naming of items increases looking time overall But does not increase looking time to targets n no more than knowing a word increases looking time to its picture, in the absence of a name Naming increase probably general attentional phenomenon n More variable input! Conclusions more looking at pictures representing known words condition (F 1, 17 = 4. 316, p =. 053, 2 =. 20) n Study 2 - Discussion Children may look at target-known pictures more than nontarget or unknown pictures n But may not be because of N 3 C principle n Simply knowing a word increases looking n N 3 C seems to apply preferentially when parent is “helping” n Any effect of child’s vocabulary? n References “Unknown target” (child does not know “bear”) Effect of parent looking/speaking/pointing? n n n 10 parents: parent behaviour videoed and scored Parents all did something n either looked, pointed, or spoke at some point during testing Group really too small for analysis n But some interactions 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.