Bilingualism and Cognitive Development: Evidence for Changes in Attentional Control

Ellen BialystokYork University

Language Representation in Bilinguals

L1

L1

L1

L1

L1

L1

L1

L1

L2

L2

L2

L2

L2

L2 L2

L2

L2

L2

L2

L2

L2

L2

L2

L2

L1

L1

L1

L1

L1

L1

L1

L1Attend

IgnoreAttend

Ignore

Switch

ExecutiveControl

ExecutiveControlAdvantages

Development of Executive Processes

• Last area of brain (frontal lobes) to mature• Last cognitive skills to develop in

childhood, first to decline with aging• Children typically develop control over

attention and inhibition at about 5 years• Experience in managing two languages

may promote this development

1. Perceptual Organization and Meaning

• Embedded Figures Test is test of field-dependence/field-independence and a measure of intelligence

• Compare to misleading context of ambiguous figures

• Participants – 5 ½ years olds27 Monolinguals26 Bilinguals

Children’s Embedded Figures Test

• Perceptual analysis of complex figure to find simple component

• Requires inhibition of overall perceptual configuration and interpretation of parts

• Items divided into tent (triangle) and house shapes

• Score is total of two sections

Embedded Figures Test: Tent

Embedded Figures Test: House

Embedded Figures TaskBialystok & Shapero, 2005

0

2

4

6

8

10

12

14

Tent House

Item Type

Mea

n N

umbe

r C

orre

ct

MonolingualBilingual

Ambiguous Figure Reversals

• Ability to see an alternative interpretation of an ambiguous figure develops at around 6 years

• Need to assign new interpretation to perceptual stimulus inhibit previous interpretation?

• Create a graduated scale for degree of ability

Ambiguous Images

Content Figure-Ground

Scoring System

• 5: Spontaneous identification• 4: Identify one feature• 3: Identify second feature• 2: Name alternative image• 1: Disambiguated image of

alternative • 0: No idea!

Criterion: Child indicates two features of alternative image

Points

Disambiguated Images (1 point)

“man” “rat”

Reversibility ScoresBialystok & Shapero, 2005

00.5

11.5

22.5

33.5

44.5

5

rat/man duck/rabbit vase/face sax/woman

Mea

n Sc

ore

MonolingualBilingual

** *

ContentFigure-Ground

Embedded Figures vs Reversible Figures

• EFT requires pattern analysis to find the hidden component. There is no conflict.

• Ambiguous figures requires re-assigning a meaning that conflicts with the current interpretation. It must stop being “a duck” for the image to reverse.

• Effect of bilingualism is in processing conflict

2. Dimension Change Card Sort Task

• Bidimensional stimuli sorted by one dimension, then other

• Young children fail to switch second time

• Perceptual: colour-shape• Conceptual: function-

location

Shape-Colour

Bialystok, 1999: N=60, 4 ½ yrsBialystok & Martin, 2004: Study 1 N=67,6 yrs; Study 3 N=51, 5 ½ yrs

Function-Location

Post-Switch Scores in DCCSBialystok, 1999; Bialystok & Martin, 2004

Perceptual Stimuli:Colour-Shape

0123456789

10

B&M,2004,1 B&M,2004,3

Monolingual Bilingual

Conceptual Stimuli:Function-Location

0123456789

10

B,1999 B&M,2004

Monolingual Bilingual

* *

Perceptual vs. Conceptual Stimuli

• Perceptual feature salient – represented “round one”; Re-represent “yellow one”

• Conflict between representations (cf. Ambiguous Figures)

• Function-location stimuli have no perceptual conflict – stimulus interpreted individually (cf. Embedded Figures)

• Bilingual advantage for resolving perceptual conflict

3. Simon Effect

• Prepotent response to position cues• Stimuli contain target and (irrelevant)

position cuesPosition consistent with R congruentPosition conflicts with R incongruent

• Simon effect (SE) is RT cost for incongruent trials

• Conflict resolution should be easier for bilinguals, so smaller SE

Rule: red square left green square right

RL

Simon EffectRule: red square left green square right

Congruent

Incongruent

SE = Incongruent - Congruent

RL

Simon Task by Language for ChildrenMartin & Bialystok, submitted

200

400

600

800

1000

1200

1400

1600

1800

Congruent Incongruent Simon Effect

Mea

n R

T m

s

MonolingualBilingual

N=344 ½ year olds

* *

*

Adults and Aging: Simon TaskBialystok, Craik, Klein, & Viswanathan, 2004

• 94 participants between 30 and 80 years• Half bilingual matched by age• Background measures of working memory,

language proficiency, intelligence (Cattell)

ControlRule: red square left green square right

RL

Mean RT for Control by Decade

0150300450600750900

1050120013501500

30-39 40-49 50-59 60-69 70-79

Age

Mea

n R

T (m

s)

Monolingual Bilingual

Simon EffectRule: red square left green square right

RL

Mean Simon Effect by Decade

0100200300400500600700800900

1000

30-39 40-49 50-59 60-69 70-79

Age

RT

Diff

eren

ce (m

s)

Monolingual Bilingual

4. Stroop Task

• Prototypical task for frontal executive processing

• Bilingual Stroop effect: SE across languages = SE within languages

• (Almost) no research examining SE within a language comparing conflict resolution for monolinguals and bilinguals

• Bilinguals should resolve conflict more easily and show a smaller SE

Sample

• 96 participants: 24 young monolinguals, 21 years24 young bilinguals, 20 years24 older monolinguals, 67 years24 older bilinguals, 68 years

• Bilinguals fully balanced lifelong bilinguals• Variety of language pairs

Stroop Task

XXX

RED BLUE

RED

Experimental

Congruent

Incongruent

ControlStroop Effect

Colour

Word

Correct answer: “Red”

Stroop Control Conditions

XXX

RED

Control

Colour200

300

400

500

600

700

800

Colour

Young:Mono Young:BiOld:Mono Old:Bi

Age: n.s.Lang: F < 1

200

300

400

500

600

700

800

Word

Young:Mono Young:BiOld:Mono Old:Bi

Age: n.s.Lang: F < 1Word

Stroop Effect by Group

100

150

200

250

300

350

Stroop Effect

Mea

n D

iff R

T (In

cong

- C

ong)

Young MonoYoung BilingOld MonoOld Biling

Language Representation in Bilinguals

L1

L1

L1

L1

L1

L1

L1

L1

L2

L2

L2

L2

L2

L2 L2

L2

L2

L2

L2

L2

L2

L2

L2

L2

L1

L1

L1

L1

L1

L1

L1

L1Attend

IgnoreExecutiveControl

Switch

Lexical Conflict

Lexical Retrieval Deficits

ExecutiveControlAdvantages

Bilingualism and Lexical Access

• Control advantages and EF processing differences come from linguistic conflict

• Need to resolve linguistic conflict beneficial to these processes

• But the problem of linguistic conflict remains

• Are there group differences in lexical access?

Receptive Vocabulary

• PPVT scores as rough vocabulary size

• Frequent reports of bilingual deficits

• Combined data: N=5285 yrs: N=976 yrs: N=3417 yrs: N=568 yrs: N=34 80

859095

100105110115120

5 6 7 8

Monolingual Bilingual

* * *

Lexical Retrieval

0102030

40506070

Boston Fluency

Young:Mono Young:BiOld:Mono Old:Bi

* ** *

• Younger & older adults (from Stroop), N=96

• Boston Picture Naming

• Letter and category fluency“F” “A” “S” “Animals”

Bilingual Effects on Cognition

L1

L1

L1

L1

L1

L1

L1L1

L2

L2

L2

L2

L2

L2 L2

L2

L2

L2

L2

L2

L2

L2

L2

L2

L1

L1

L1

L1

L1

L1

L1

L1

Lexical Conflict

CognitiveControlAdvantages

Lexical Retrieval Deficits

Summary of Bilingual EffectsAdvantages to executive function• Control of attention

Simon task, Stroop task• Switching

Embedded figures, DCCSDisadvantages to lexical retrieval• Vocabulary

PPVT• Fluency

Fluency and Boston Naming

Credits

• Fergus Craik• Ray Klein• Gigi Luk• Michelle Martin• Jeni Pathman• Dana Shapero• Mythili Viswanathan

Funding