Frances Balcomb Temple University Convergence and divergence in representational systems - place learning and language in young children Frances Balcomb Temple University 1

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? 2

Funding provided by Spatial Intelligence and Learning Center National Science Foundation Science of Learning 3

Why study space… 4

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 5

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” 6

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 7

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 8

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 9

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 10

Foundational Processes Language is well - studied Space is less well-studied 11

Place Learning Navigational techniques Egocentric Allocentric dg Retrace your steps Allocentric Landmarks Place learning dg 12

What is known about early navigation? 13

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 14

Acredolo & Evans, 1980 6-, 9-, & 11-month-olds Modified version of the plus-maze No feature, plain feature, salient feature, salient indirect feature 15

“tone” 16

“tone” 17

“tone” egocentric allocentric 18

No Cue “tone” 19

Non-Salient Cue “tone” 20

Salient Direct Cue “tone” 21

Salient Indirect Cue “tone” 22

Results Cue Type age None Non Salient Salient Direct Salient Indirect 6 months Ego Mixed 9 months Ego (mixed) Allo 11 months Ego & Allo (mixed) Mixed (allo) 23

How does this compare to adults and non-humans? After few trials - place response After many trials - shift to egocentric Individual variability exists 24

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 25

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) 26

Newcombe et al 1998 X X 27

Newcombe et al 1998 Feature3 Feature1 X Feature2 28

Newcombe et al, 1998 Newcombe, Huttenlocher, Drummey & Wiley (1998), Cognitive Development 29 29

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 30

Morris Water Maze 31

Morris Water Maze Room Cue 3 Room Cue 1 Room Cue 2 32

Morris Water Maze 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 33

Morris water maze for kids 34

Methods Subjects Children aged 16-24 months, (m=20.6) N=32 Tasks Parents - language measure Children - place learning 35

Expressive Language MacArthur Communicative Inventory for Toddlers Parent report 226 word checklist - expressive language only 100 Nouns, 100 verbs, 26 prepositions 36

Place Learning Materials 10’ diameter carpeted circle divided into squares, off center Battery operated puzzle Tasks Locate puzzle hidden under carpet Remember puzzle location 37

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cueA cueC cueD cueB X X 39

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 40

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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 42

Results 43

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 44

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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) 49

Peripheral Searches (proximal cue use) cueA cueC cueD cueB X 50

X Correct Quadrant Search (distal cue use = place learning) cueA cueC cueD cueB X 51

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 52

Unrelated Searches cueA cueC cueD cueB X 53

searches, age, and goal finding Intercorrelations between search type, age and goal finding Measure Age Spatial Non-spatial # times goal found -- .45* -.62* .63* .-73* .46 * -.48 * 54

Type of search and goal finding by age 55

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Types of Spatial Searches with Age 57

Space and Language Intercorrelations between language and spatial searches Measure Nouns Verbs Preps # times goal found # searches under “other” -- .83 .67 .21 (.30) .33 (.09) .79 .11 (.59) .38 (.05) .39 (.05) .23 (.25) -.34 (.08) 58

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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 61

Representations that rely on understanding spatial relationships between objects emerge behaviorally (successful goal searches) and linguistically (prepositions) on a developmentally related timescale 62

Future Directions Modified plus maze What affects differential weighting Caudate - HC competition? Episodic-like/context-dependent memory Get a job 63