1 convergence and divergence in representational systems - place learning and language in young...
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Convergence and divergencein representational systems -
place learningand language in young children
Frances Balcomb
Temple University
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• Emergent place learning in the Morris water maze • Early expressive language
– What does early place learning look like?– How does PL relate to other types of spatial navigation?– How does PL relate to other types of cognitive
development?
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Funding provided by
Spatial Intelligence and Learning Center
National Science Foundation Science of Learning
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Space and Language
• Complementary representational systems• Undergo rapid development from about 16-24
months– Vocabulary explosion, 2-word combinations– Shift from ego to allocentric, place learning
• When you put space and language together, you merge two very powerful representational systems and level up
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Spatial Representation
• Allows for representation in non-linear, non-linguistic domains
• Is evident in – Gesture– Drawings– Language
• “looking forward to it”
• “In the back of my mind”
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Space and Language
• Complementary representational systems• Undergo rapid development from about 16-24
months– Vocabulary explosion, 2-word combinations– Shift from ego to allocentric, place learning
• When you put space and language together, you merge two very powerful representational systems and level up
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Space and Language - Dissociations
• Working Memory – Baddeley: phonological loop & visuospatial sketchpad
• Standard Intelligence– WAIS - perceptual-organization and verbal composites– Woodcock-Johnson - visuo-spatial and phonemic awareness
clusters• Brain areas
– Language: Broca’s & Wernicke’s– Space: hippocampus et al
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Space and Language - Connections
• Specificity Hypothesis (Gopnik & Meltzoff 1986, 1987)• Evidence from children with Williams Syndrome
– Landau & Zukowski, 2003 - path terms (prepositions)
– Phillips, Jarrold, Baddeley, Grant, & Karmiloff-Smith (2004)
• In, on, above, below, in front, behind, shorter/smaller, longer/bigger
• Brain areas may overlap– Temporal lobe, parahippocampus, dorsal and
ventral streams
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Summary
• In some aspects space and language are able to function independently and can be accessed separately
• If you look in the right places, they appear to be inter-linked
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Place Learning
• Navigational techniques– Egocentric
• Retrace your steps
– Allocentric• Landmarks• Place learning
• dg
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What is known about early navigation?
• Ordered progression of skill development– ego-centric, beacon/landmark, place learning
• Dynamic use of spatial skills, even early in development– Familiarity, cue salience, task demands
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Acredolo & Evans, 1980
• 6-, 9-, & 11-month-olds• Modified version of the plus-maze• No feature, plain feature, salient feature, salient indirect
feature
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Results
Cue Type
age None Non Salient
Salient Direct
Salient Indirect
6 months Ego Ego Mixed Ego
9 months Ego Ego (mixed)
Allo Ego (mixed)
11 months Ego Ego & Allo (mixed)
Allo Mixed (allo)
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How does this compare to adults and non-humans?
• After few trials - place response• After many trials - shift to egocentric• Individual variability exists
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Brain - behavior issues
• Strategy types related to – caudate/striatum (egocentric/response learning– hippocampus (place)– May be competitive (Compton et al, 2004)
• HC learning vs Caudate– HC fast, not dependent on feedback– Caudate - slower, dependent on error signal
• In development the picture is not so clear
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What is known about early navigation?
• Place emerges rapidly between 18-24 months– Children begin to use external cues to improve
search accuracy • Newcombe, Huttenlocher, & Drummey, & Wiley (1998)
– Children begin to use relational searches• Sluzenski, Newcombe & Satlow (2004)
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Research Questions
• Are there individual differences in early place learning abilities?
• Do language and spatial representations develop independently?
• What is the relationship between the developing brain and emergent behavior?
• Relationship between place learning and other navigation types
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Because this task has been well researched in adults and non-human animals we know
• Hippocampal dependent• Good performance looks different from poor
performance• There are gender differences in adults• Aging adults differ from younger adults
Morris Water Maze
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Methods
• Subjects– Children aged 16-24 months,
(m=20.6) – N=32
• Tasks – Parents - language measure– Children - place learning
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Expressive Language
• MacArthur Communicative Inventory for Toddlers• Parent report• 226 word checklist - expressive language only
– 100 Nouns, 100 verbs, 26 prepositions
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Place Learning
• Materials– 10’ diameter carpeted circle divided into squares, off
center– Battery operated puzzle
• Tasks – Locate puzzle hidden under carpet– Remember puzzle location
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Procedures
• Familiarization• Learning
– 4 trials to learn the puzzle’s location– Different points of entry
• Test– Same as learning trials– No puzzle
• Control– Control for motivation & walking speed– Puzzle clearly visible
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Predictions
• Place Learning – Older children > younger (goal-finding)
• Language– Older children > younger (more expressive vocabulary)
• Place learning & language– No correlation between overall language and PL– Correlation between prepositions & PL
• Often in development it’s very hard to find correlations with language
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Results
• Age correlates with– # times goal found: r(26)=.63, p<.001– Expressive language: r(26)=.7, p<.001
• Partial out age– No correlation between # times goal found and
expressive language r(25)=.19, p=.35
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0%
20%
40%
60%
80%
100%
16-18 19-21 22-24
Age in months
Percentage achieved
goal found/5
Expressivevocab/226
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More detailed analyses
• Search types– Spatial (perimeter, correct quad)– Non spatial (under self, other, unrelated)
• Language– Nouns, verbs, preps, total lang, relational lang (verbs +
prepositions)
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Non-spatial searches
• Under self (child lifts tile under him/herself)• Under other (child approaches experimenter & lifts tile
under her)• Unrelated - none of the above
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searches, age, and goal finding
Measure Age Spatial Non-spatial # times goal found
Age -- .45* -.62* .63*
Spatial -- .-73* .46 *
Non-spatial -- -.48 *
Intercorrelations between search type, age and goal finding
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Type of search and goal finding by age
0%
20%
40%
60%
80%
100%
16 17 18 19 20 21 22 23 24
Age in months
goal found/5
spatial
non-spatial
0%
20%
40%
60%
80%
100%
16 17 18 19 20 21 22 23 24
Age in months
goal found/5
spatial
non-spatial
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Types of Spatial Searches with Age
0%
20%
40%
60%
80%
100%
16 17 18 19 20 21 22 23 24
Age in months
spatial
adj
periph
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Space and Language
Measure Nouns Verbs Preps # times goal found # searches under “other”
Nouns -- .83 .67 .21 (.30) .33 (.09)
Verbs -- .79 .11 (.59) .38 (.05)
Preps -- .39 (.05) .23 (.25)
# times goal found
-- -.34 (.08)
Intercorrelations between language and spatial searches
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prepositions and place learning
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0.16
0.18
0.2
0 1 2 3 4 5 6
# times goal found
proportion of preps/total vocab
60
0
1
2
3
4
5
6
0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2
proportion preps/total language
found/5
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Summary
• Place learning and expressive language develop independently with age in 16-24 month old children– Evidence of spatial searching 1-2 months before reliable
goal finding – Rapid change at around 20-21 months
• Acquisition of prepositions and place learning correlate– Convergent evidence comes from research with children
who have Williams Syndrome• Acquisition of other language marginally correlates with
searching under a person (social?)– Interestingly, though, in this task it’s misleading
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Representations that rely on understanding spatial relationships between objects emerge behaviorally (successful goal searches) and linguistically (prepositions) on a developmentally related timescale