Cultural evolution and communication yield structured languages in - - PowerPoint PPT Presentation

▶

Jul 28, 2023 226 likes •728 views

Cultural evolution and communication yield structured languages in an open-ended world Jon W. Carr, Kenny Smith, Hannah Cornish, Simon Kirby Carr, J. W., Smith, K., Cornish, H., & Kirby, S. (2016). The cultural evolution of structured

SLIDE 1

Jon W. Carr, Kenny Smith, Hannah Cornish, Simon Kirby

Cultural evolution and communication yield structured languages in an open-ended world

Carr, J. W., Smith, K., Cornish, H., & Kirby, S. (2016). The cultural evolution of structured languages in an open-ended, continuous

world. Cognitive Science. doi:10.1111/cogs.12371

SLIDE 2

What shapes language?

Language

SLIDE 3

What shapes language?

Language

Expressivity

SLIDE 4

What shapes language?

Language

Learnability

Kirby, Tamariz, Cornish, & Smith, 2015, Cognition

Expressivity

SLIDE 5

What shapes language?

Kemp & Regier, 2012, Science

Language

Kirby, Tamariz, Cornish, & Smith, 2015, Cognition

Informativeness Simplicity

SLIDE 6

What shapes language?

Kemp & Regier, 2012, Science

Language

Kirby, Tamariz, Cornish, & Smith, 2015, Cognition

Bequemlichkeitsstreben Deutlichkeitsstreben

SLIDE 7

Iterated learning

Emergence of compositional structure in the signals Emergence of categorical structure  in the meanings

Kirby, Cornish, & Smith, 2008, PNAS Xu, Dowman, & Griffiths, 2013, Proc R Soc B

SLIDE 8

Can we see the emergence

f compositional structure

under a continuous, open- ended meaning space?

SLIDE 9

Experiments

Experiment 1 Pressure to be learnable from cultural transmission No pressure to be expressive Result: Categories emerge in the meaning space Experiment 2 Pressure to be learnable from cultural transmission Pressure to be expressive from communication Result: “Compositional” structure emerges in the signals

SLIDE 10

Experiment 1

SLIDE 11

Stimuli

SLIDE 12

Vast in magnitude  6 × 1015 possible triangle stimuli Complex dimensions  Many possible dimensions to the space Continuous  On each dimension, the triangle stimuli vary over a continuous scale

SLIDE 13

DYNAMIC SET 1 STATIC SET DYNAMIC SET 2 STATIC SET DYNAMIC SET 0

Generation 1 Generation 2 Generation 3

Training input Test

utput

Training input Test

utput

Training input Test

utput etc…

etc…

Experimental design

SLIDE 14

Training phase

×144

SLIDE 15

Test phase

×96

SLIDE 16

Expressivity

1 2 3 4 5 6 7 8 9 10

Generation number

10 20 30 40 50

Number of unique strings

1 2 3 4 5 6 7 8 9 10

Generation number

0.0 0.2 0.4 0.6 0.8 1.0

Transmission error Chain A Chain B Chain C Chain D

Learnability

SLIDE 17

SLIDE 18

SLIDE 19

SLIDE 20

SLIDE 21

SLIDE 22

fama

SLIDE 23

fama

SLIDE 24

fama p a m a

SLIDE 25

fama p a m a fod

SLIDE 26

fama p a m a fod muaki

SLIDE 27

fama p a m a fod muaki kazizui

kazizizui k a z i z i z u

SLIDE 28

Generation

10

Generation

9

Generation

8

Generation

7

Generation

6

Generation

5

Generation

4

Generation

3

Generation

2

Generation

1

Generation

SLIDE 29

Generation

10

Generation

9

Generation

8

Generation

7

Generation

6

Generation

5

Generation

4

Generation

3

Generation

2

Generation

1

SLIDE 30

Generation

10

Generation

9

Generation

8

Generation

7

Generation

6

Generation

5

Generation

4

Generation

3

Generation

2

SLIDE 31

Generation

10

Generation

9

Generation

8

Generation

7

Generation

6

Generation

5

Generation

4

Generation

3

SLIDE 32

Generation

10

Generation

9

Generation

8

Generation

7

Generation

6

Generation

5

Generation

4

SLIDE 33

Generation

10

Generation

9

Generation

8

Generation

7

Generation

6

Generation

5

SLIDE 34

Generation

10

Generation

9

Generation

8

Generation

7

Generation

6

SLIDE 35

Generation

10

Generation

9

Generation

8

Generation

7

SLIDE 36

Generation

10

Generation

9

Generation

8

SLIDE 37

Generation

10

Generation

9

SLIDE 38

Generation

10

pika mamo

SLIDE 39

Experiment 2

SLIDE 40

DYNAMIC SET 1 STATIC SET DYNAMIC SET 2 STATIC SET DYNAMIC SET 0

Generation 1 Generation 2 Generation 3

Training input Communicative

utput

Training input Communicative

utput

Training input Communicative

utput

etc… etc…

Experimental design

SLIDE 41

! " ×96

SLIDE 42

Expressivity

1 2 3 4 5 6 7 8 9 10

Generation number

10 20 30 40 50

Number of unique strings

1 2 3 4 5 6 7 8 9 10

Generation number

0.0 0.2 0.4 0.6 0.8 1.0

Transmission error Chain I Chain J Chain K Chain L

Learnability

SLIDE 43

1 2 3 4 5 6 7 8 9 10 −2 2 4 6 8 10 12 14

Structure

1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10

Generation number

−2 2 4 6 8 10 12 14

Sublexical structure

1 2 3 4 5 6 7 8 9 10

Generation number Chain A Chain C Chain B Chain D Chain I Chain K Chain J Chain L

Experiment 1 Experiment 2

Structure in the languages

SLIDE 44

SLIDE 45

SLIDE 46

SLIDE 47

SLIDE 48

SLIDE 49

The experimental design avoids several of the simplifications of previous experiments:

Continuous
Unstructured by the experimenter
Vast in magnitude
Different stimuli across generations

Experiment 1 showed that cultural evolution can deliver languages that categorize the meaning space under pressure from learnability. Experiment 2 combined a pressure for learnability with a pressure for expressivity derived from a genuine communicative task. This gave rise to languages that use both categorization and string-internal structure to be both learnable and expressive. However, unlike previous work, this emergent structure was sublexical rather than morphosyntactic, and as such bears similarities to certain aspects of natural lexicons.

Conclusions