What are symbols? Something that stands for something else Not necessarily similar to their referent Not natural – Created Use of symbols ~ 18 months Words, gestures, pictures?
By 18 months… Words are interpreted referentially (Xu, et al. 2005) Paradigm: Two-word trial, One-word trial Surprised when # of kinds didn’t match # of labels At chance for emotional expressions Works at 10 months Iconic gestures are recognized (Tomasello et al., 1999) Children take a hammering motion as referring to hammers, e.g.
Pictures as Symbols Why are we interested in pictures? Different from other symbols? On one theory, pictures are more salient as objects than words or gestures, and hence harder to see as symbols Pictures present a puzzle: Innate ability to perceive content of pictures (Hochberg and Brookes 1969) Yet apparent difficulty understanding that they refer to the world ‘Pygmalion’ errors (DeLoache, et al. 1998) Dollhouse task failure until 30 months (DeLoache, 1991, 2000)
Pictures as Symbols To review: At first, mistake for actual referents Somehow eventually, like adults, children recognize symbols as representations Dual representation At what point recognize symbolic significance?
Role of Language Language plays role? Attract attention Mediates reference Evidence of its importance Callaghan (2000) Match picture with object Only success when lexical labels could individuate them Only when familiar Winkler-Rhoades No label, designate map for placing doll, not targets Unfamiliar, need labels (?)
ISU - Questions How do we learn that pictures can refer to things? That they can inform us about how the world is? Does language play a role in helping children figure out representational status of pictures?
Xu and Baker (2005) Modified manual search procedure To understand how infants use property or kind info for object individuation
Xu and Baker (2005) Results Infants looked longer on switch trials Labels did not matter Familiarity did not matter For us, important to establish that they would be surprised at switch trials
ISU – Pilot Method 18 month olds 11 in familiar label, 7 in novel label, 7 in novel no label Very similar to Xu and Baker (2005) Box and novel objects Switch trials and non-switch trials Familiar, unfamiliar Labeled, unlabeled Who wants to be a baby?
ISU - Pilot Alternatives/Logic Longer reaching time on Switch than No Switch Expect the same object to be present, confused No difference in reaching time between Switch and No Switch (at chance) No expectations on what object should be present Perhaps just interest in reaching, or not reaching
Labels/Familiar Alternatives Labels Increased recognition of symbolic significance At chance Familiarity Increased recognition of symbolic significance At chance
ISU - Method Same general procedure Use pictures instead of first object remove/replace Still Switch/No Switch trials Still novel objects Familiar/Unfamiliar Label/No label
ISU – Alternatives/Logic Could use picture as symbol On Switch trials, longer reaching time Use picture to signify one object inside Confusion on why other object Could NOT use picture as symbol No difference in reaching times between Switch and No Switch Doesn’t use picture as information at all No expectations At chance
Further Directions Specific/generic? Older/younger? Within same kind? Any ideas from you?