protolanguage: between holophrastic and atomic meanings

37
Protolanguage: Between Holophrastic and Atomic Meanings Mike Dowman University of Tokyo January 23, 2007

Upload: akeem-powell

Post on 03-Jan-2016

29 views

Category:

Documents


2 download

DESCRIPTION

Protolanguage: Between Holophrastic and Atomic Meanings. Mike Dowman University of Tokyo January 23, 2007. Protolanguage. At some time in the past humans didn’t have language. What did the first human languages look like? Were there simple languages before complex ones?. Starting Small. - PowerPoint PPT Presentation

TRANSCRIPT

Page 1: Protolanguage:  Between Holophrastic and Atomic Meanings

Protolanguage: Between Holophrastic and

Atomic Meanings

Mike Dowman

University of Tokyo

January 23, 2007

Page 2: Protolanguage:  Between Holophrastic and Atomic Meanings

Protolanguage

• At some time in the past humans didn’t have language.

• What did the first human languages look like?

• Were there simple languages before complex ones?

Page 3: Protolanguage:  Between Holophrastic and Atomic Meanings

Starting Small

• The first humans could only articulate and/or perceive a limited number of distinct words

No phonologyLittle or no syntax They only tried to convey a limited num

ber of simple meanings

Page 4: Protolanguage:  Between Holophrastic and Atomic Meanings

Bickerton (1990, 1996)

• Words in the first languages were like modern words

• Labeled preexisting concepts and entities

• Words used in short stringsNo fixed word orderWords can be omitted

Page 5: Protolanguage:  Between Holophrastic and Atomic Meanings

Modern Day Examples of Protolanguage

• Children under two• Speakers of pidgins• Adults deprived of language in childhood• Trained apes:Nim eat Nim eat

Tickle me Nim play

Me banana you banana me you give

Banana me me me eat

Page 6: Protolanguage:  Between Holophrastic and Atomic Meanings

Wray (1998)

• The First Words in Protolanguages were Holophrastic

Each word conveyed a whole complex meaning (e.g. Give me the meat)

• Chimpanzee vocal noises and gestures are holistic

Inform about location of food, threaten, get another chimpanzee to do something

Page 7: Protolanguage:  Between Holophrastic and Atomic Meanings

Syntactic Abilities

• Word categories• Permissible and ungrammatical sequenc

es• Mapping from structures to meanings• Breaking meanings into bitsMaking sure all the bits are expressed on

ceNo bits are expressed more than once

Page 8: Protolanguage:  Between Holophrastic and Atomic Meanings

The Agents have none of these Syntactic Abilities

Can only associate words and meaningsCan’t associate part of a meaning with part

of an utteranceWhen speaking just choose the word(s) th

at seem to be most appropriate given the whole proposition to be expressed

The model is therefore of protolanguage onlyNot the transition to syntax

Page 9: Protolanguage:  Between Holophrastic and Atomic Meanings

The Iterated Learning Model

• One agent per generation

• Each agent sees meanings and hears words produced by the agent in the previous generation

• Agents’ knowledge of language is just a list of meanings they’ve heard each word used to express

Page 10: Protolanguage:  Between Holophrastic and Atomic Meanings

Nature of Utterances

• Each utterance consisted of only a single word

• Agents could use only a small number of words (limited communicative capacity)

• Available words fixed throughout each simulation

Page 11: Protolanguage:  Between Holophrastic and Atomic Meanings

Meaning Representations

• Small number of semantic primitives (limited conceptual capacity)

• Each utterance would try to express a complex meaning represented by a group of three different primitives

hunt, pig, forest means ‘Hunt pigs in the forest’

dog, pig, sleep means ‘Dogs and pigs are sleeping’

Page 12: Protolanguage:  Between Holophrastic and Atomic Meanings

Agents’ Choice of Words

• Agents use the word whose past uses have been most similar to the current meaning

• If current meaning is: eat, house, pig• Previously heard used to express:eat, house, doghunt, forest, pig Match = 4/9hunt, forest, pig

Page 13: Protolanguage:  Between Holophrastic and Atomic Meanings

Agents’ Choice of Words

• If degree of match is one, agent will always use that word

• Otherwise will use any available unused word (and the word-meaning pair remembered)

• Otherwise pick highest degree of match (choosing at random in the event of a tie)

Page 14: Protolanguage:  Between Holophrastic and Atomic Meanings

Simulations

• Each meaning contained 3 elements from a set of 10 (so 120 distinct complex meanings)

• Each agent produced 1000 utterances for the agent in the next generation (each expressing a randomly chosen meaning)

• Simulations were run for ten generations• The number of available words was varied

Page 15: Protolanguage:  Between Holophrastic and Atomic Meanings

Emergence of Words with Atomic Meanings

• In the first simulation the agents could only use 10 distinct words

• All the agents made use of all 10 available words

• Most words were used only when one particular semantic element was present

Their meanings appear to correspond to those elements

Page 16: Protolanguage:  Between Holophrastic and Atomic Meanings

Example Atomic Type Words

Meanings Expressed by Word (frequency in brackets)

Description of Word Meaning

forest, pig, eat (12)

eat, dog, gather (10)

forest, gather, eat (11)

hunt, eat, pig (11)

fight, pig, eat (6)

gather, eat, pig (7)

house, eat, gather (9)

dog, fight, eat (7)

eat, hunt, fight (11)

gather, eat, fight (10)

gather, eat, sleep (13)

dog, eat, pig (4)

gather, hunt, eat (4)

Word denotes eat

Meanings Expressed by Word (frequency in brackets)

Description of Word Meaning

dog, river, forest (7) pig, forest, dog (10) river, dog, pig (17) eat, dog, forest (10)

dog, forest, gather (5) dog, pig, fight (7)

forest, dog, fight (6) fight, river, dog (10) forest, sleep, dog (5) sleep, dog, river (5)

Word denotes dog

The words are like modern nouns or verbs

Page 17: Protolanguage:  Between Holophrastic and Atomic Meanings

Emergence of Holophrastic Words

• In the next simulation the agents could use 150 distinct words

• All agents used 120 of these words

• Each word expresses a single complex meaning

These words are all holophrastic

Page 18: Protolanguage:  Between Holophrastic and Atomic Meanings

Example Holophrastic Words

Meanings Expressed by Word

(frequency in brackets)

Description of Word Meaning

sleep, pig, hunt (5) Word denotes events or objects

containing all the elements sleep,

pig and hunt

pig, house, fight (9) Word denotes events or objects

containing all the elements pig,

house and fight

forest, fight, hunt (10) Word denotes events or objects

containing all the elements forest,

fight and hunt

Page 19: Protolanguage:  Between Holophrastic and Atomic Meanings

Emergence of Intermediate Types of Language

• What happens when the number of available words is in between the number of semantic elements and the number of complex meanings?

• Do we get a mixture of atomic and holophrastic words?

A new simulation with 50 available words tested this

All agents used all the available words

Page 20: Protolanguage:  Between Holophrastic and Atomic Meanings

Language contains words with varying degrees of holophrasticity

It’s intermediate between a protolanguage with atomic words and a holophrastic one

Meanings Expressed by Word

(frequency in brackets)

Description of Word Meaning

sleep, forest, gather (7) Word denotes events or objects

containing all the elements sleep,

forest and gather

forest, river, house (5)

house, river, fight (8)

forest, river, fight (6)

Word denotes river, but only in

relation to forest, house or fight

sleep, hunt, eat (13)

sleep, eat, river (11)

pig, eat, sleep (8)

eat, gather, sleep (11)

sleep, fight, eat (6)

sleep, dog, eat (9)

forest, sleep, eat (6)

Word denotes events or objects

containing both of the elements

sleep and eat

gather, sleep, pig (10)

pig, dog, sleep (10)

pig, sleep, house (5)

Word denotes events or objects

containing both of the elements

sleep and pig, but only in relation

to gather, dog or house

dog, hunt, house (5)

hunt, eat, dog (6)

eat, dog, house (12)

house, hunt, eat (5)

Denotes meanings containing

three of the elements dog, hunt,

house and eat

Page 21: Protolanguage:  Between Holophrastic and Atomic Meanings

Varying Degrees of Holophrasticity

• The frequency of each type of word depended on the number of distinct words available

• With 50 words there were:10 holophrastic words, 35 words containing two fixed s

emantic elements, 4 words containing one fixed element, and 1word containing no fixed elements at all

With a smaller number of distinct words, the languages become less holophrastic

With more available words they became more holophrastic

Page 22: Protolanguage:  Between Holophrastic and Atomic Meanings

Fewer Words than Semantic Elements

• What if the agents could not even produce one distinct word for each semantic element?

• (Or alternatively what if they knew so many semantic elements they could use more than there were words?)

• A new simulation was conducted with only 5 distinct words available

Page 23: Protolanguage:  Between Holophrastic and Atomic Meanings

Emergent Words

• Three words had one fixed semantic element

• One word used any three of the other seven semantic elements

• The final word contains at least two of the elements eat, gather and pig

This is a new type of word, and is partly holophrastic

Page 24: Protolanguage:  Between Holophrastic and Atomic Meanings

Co-evolution of Agents and Protolanguages

• What happens as agents communicative and conceptual capacities evolve phylogenetically?

• We would expect the agents’ protolanguages to rapidly adapt to the agents new capacities

• How will the degree of holophrasticity change over time?

Page 25: Protolanguage:  Between Holophrastic and Atomic Meanings

Increasing Communicative Capacity

• The first agents could use only a single word

• After every 10 generations the number of words they could use was increased by 1

• Number of semantic elements fixed at 10

• 1300 generations simulated

Page 26: Protolanguage:  Between Holophrastic and Atomic Meanings
Page 27: Protolanguage:  Between Holophrastic and Atomic Meanings

Increasing Conceptual Complexity

• In this simulation there were always 120 words available

• Initially there were 10 semantic elements• After every 10 generations the number of avai

lable semantic elements was increased by 1• This simulation was also run over 1300 gener

ations (so there were 447,580 different complex meanings at the end of the simulation)

Page 28: Protolanguage:  Between Holophrastic and Atomic Meanings
Page 29: Protolanguage:  Between Holophrastic and Atomic Meanings

Transitions between Atomic and Holophrastic Words

• The first simulation showed a progression from atomic words to holophrasis

• The second from holophrasis to atomic words

So depending on the relative rates of monotonic evolution of communicative and conceptual capacity we could see multiple swings between each type of protolanguage

Page 30: Protolanguage:  Between Holophrastic and Atomic Meanings

Multiple Word Utterances

Did the first protolanguage utterances contain single or multiple words?

protolanguage

gorillas humans chimps

multi-word proto-languages

Page 31: Protolanguage:  Between Holophrastic and Atomic Meanings

Multiple Word Utterances

• Maximum length of utterances was fixed at 3 words• If agents knew a word whose past uses exactly matched

the current meaning they used it (and nothing else)• Otherwise if a new word was available they used that (a

nd remembered it)• Finally, if none of the above apply, the agents chose the

3 closest matches to the current meaning.

Each of these words was then paired with the current meaning by the hearing agent

Page 32: Protolanguage:  Between Holophrastic and Atomic Meanings

• With 10 words, some express all or most meaning elements equally

• Many fewer fully holophrastic words• More words with 2 common meanings than distinct 2

element combinations (45)

Number of Words

Common Elements

10 50 90 150

0 3 3 6

1 7 9 8

2 38 71

3 5 120

Page 33: Protolanguage:  Between Holophrastic and Atomic Meanings

E-Language and I-Language

• If we look at agents’ internal linguistic representations (I-Language) we only see an unanalyzed list of the past uses of a word

• However, if we could only observe the agents’ speech (E-Language) and the meanings they tried to express we would (in some cases) be able to identify the words with specific semantic elements

So a categorization ability is not necessary for a language with categorical words to emerge

Page 34: Protolanguage:  Between Holophrastic and Atomic Meanings

Are there Atomic Pre-Linguistic Concepts?

• Isn’t boy a holophrase for young male human?

• And eat a holophrase for ingest solid stuff?

Isn’t it arbitrary what we consider to be atomic?

Also some proposed holophrases contain far more concepts than others

• So is there a clear idea of what makes a holophrase either?

Page 35: Protolanguage:  Between Holophrastic and Atomic Meanings

3 Elements Per Meaning is Arbitrary

New simulations:

• 4 elements per meaning

• out of a total of 20 meaning elements

• 3 words per utterance

• 10,000 word bottleneck

(4845 possible distinct meanings)

Page 36: Protolanguage:  Between Holophrastic and Atomic Meanings

Number of Words

Common Elements

10 20 200 1000 5000

0 8 4 77 11

1 2 16 23 32

2 100 164

3 793

4 4229

Types of Words Emerging

Page 37: Protolanguage:  Between Holophrastic and Atomic Meanings

Conclusions

• Atomic words or holophrases are not the only possibilities for protolanguages.

• If agents try to express a limited number of meanings (relative to their communicative abilities) holophrasis will results.

• With more meanings or fewer words forms, words become less holophrastic and more like atomic words.

The atomic word vs. holophrasis debate is not as clear cut as it might at first seem