language part iii language in animals language and thought

Language Part III

Language in AnimalsLanguage and Thought

Overview

• Language in nonhumans– Border collie– Alex the parrot– Kanzi / Nim chimpsky

• Language and thought– Whorfian hypothesis

Do animals have language?

• Answer to question depends on what we mean by language.

• If language means ability to communicate, do animals have language?

– yes

– no

• If language means ability to form complex linguistic representations such as syntax, do animals have language?

– yes

– no

Chaser the border collie

• Prof. John Piley spent 3 years 4-5 hrs a day teaching Chaser names for 1000+ new objects such as– 800 stuffed animals– 116 balls– 26 “frisbees”

• Also understands verbs “find”, “nose”, “paw”

• Is able to apply principle of mutual exclusivity

Video : Chaser the border collie (1:30 min.)

http://www.youtube.com/watch?v=_6479QAJuz8&feature=related

Alex the Parrot

• Alex was an African Grey Parrot that was taught an extensive vocabulary of color terms, number terms, shape terms, etc.

• He demonstrated the ability to use those terms to answer complex questions about the world.

Irene Pepperberg with Alex

Video: Alex the Parrot (2 min.)

http://www.youtube.com/watch?v=R6KvPN_Wt8IOr http://www.youtube.com/watch?v=7yGOgs_UlEc

Non-human primates

vicki

sarah & co. washoe washoe & louslis

Koko nim chimsky lana & co. kanzi & co.

Kanzi the bonobo

• Kanzi is the first bonobo (related to chimpanzees) that appears to use some elements of language

• A special keyboard was used to teach language: the lexigram: allows the teaching of spoken English words and the symbols for the words. This way, Kanzi could learn to hear and “speak”

• Kanzi can distinguish 256 words and can learn through observation

Video: Kanzi and the lexigram (2.5 min.)

http://www.youtube.com/watch?v=wRM7vTrIIis&feature=relmfu

Kanzi and syntax

• There is even some evidence that Kanzi knows some word-order constraints

• Kanzi can distinguish between these two sentences:– Make the doggie bite the snake– Make the snake bite the doggie

Video: Kanzi and novel sentences (2 min.)

http://www.youtube.com/watch?v=2Dhc2zePJFE&feature=related

Limitations of Bonobos and Chimps

• Their language productions are quite limited

• Top 6 sentences produced by Nim Chimpsky (a chimpanzee):– Eat drink, eat drink– Eat Nim eat Nim– Banana Nim Banana Nim– Drink Nim Drink Nim– Banana eat me Nim– Banana me eat banana

Animal Communication: Summary

While animal communication systems may share some properties of human language, none currently seem to be as complex as human language (syntax, reference, vocabulary size).

When other animals try to learn human language, they are much slower and do not achieve a level of competency that a human child does.

This suggests that there is something special about human language. Some ideas about why suggest that there are aspects that are unique to human biology which make this possible.

Language and Thought

Sapir Whorf Hypothesis

• The structure of one’s language influences the manner in which one perceives and understands the world. Therefore, speakers of different languages will perceive the world differently

• Two versions of Whorfian hypothesis

– Strong version: language determines our thinking; without a word to describe an experience, you cannot think about it

– Weak version: Language biases our thinking

Some questions

• Does our vocabulary of color words influence our perception of color?

• Does our language for spatial position and direction influence our spatial memory?

Range of Color: Maunsell color chips

hue

brig

htne

ss

How English speakers tend to divide these up

English

Berinmo

(Davidoff 2001)

How members from the Berinmo tribe (New Guinea) divide the colors

Language Influencing Perception in Color?

• Berinmo divides the color space differently than English. Do Berinmo speakers perceive color differently?

• If categorical effects are restricted to linguistic boundaries, the 2 populations should show markedly different responses across the 2 category boundaries (green-blue and nol-wor)

• If categorical effects are determined by the universal properties of the visual system, then both populations should show the same response patterns.

English

Berinmo

(Davidoff 2001)

Within category

Within category

Across category

Across category

Recognition Memory Task

• Subjects were given a specific munsell color chip to remember. After a 30 second delay, they were given two target chips (the old one and a new one) and had to recognize the original chip.

Test

Study

30 seconddelay

“wor” “nol”“nol” “nol”

Roberson & Davidoff (2000)

Results on Recognition Memory Task

• English speakers showed better performance for targets from across-category pairs than for those from within-category pairs for the green-blue boundary, but not for the nol-wor boundary. Berinmo speakers had the opposite pattern.

• This appears to support the Whorf hypothesis…

Roberson & Davidoff (2000)

But is this an effect on perception?

• But maybe this is a result of people naming the colors in order to make their decision. So the effect of language is not on perception of color but on strategy for encoding color

• Subjects could just remember stimulus by repeating color names to themselves (“nol,nol,nol….”).

Roberson & Davidoff (2000)

A control condition

• Eliminate effect of verbal encoding

• Verbal interference condition: subjects had to read color words during retention interval

• Visual interference condition: subjects looked at a multicolored dot pattern

For more details, see:http://www.gold.ac.uk/media/davidoff-language-perceptual-categorisation.pdf Roberson & Davidoff (2000)

Verbal interference only affects across-category identification. This suggests that subjects are using language to help them make decisions about colors that fall into different linguistic categories.

Results

Red squares = Between category identification

Blue diamonds = Within category identification

Roberson & Davidoff (2000)

Categorical Color Perception?

• Conclusion: While language has an effect on the way humans remember colors, it does not seem to alter their perception of the physical stimulus.

Spatial Frames of Reference

Languages vary in which aspects of spatial location must be obligatorily encoded

Ex: English vs. Korean/Japanese

English: Ball above tableKor/Jap: Ball table top-of [floating]

English: Ball on tableKor/Jap: Ball table top-of [be on/sticking]

Munnich, Landau & Dosher (2001)

• Munnich, Landau & Dosher (2001): Does the difference in obligatory encoding of ‘contact’ in spatial prepositions in English vs. Korean/Japanese influence nonlinguistic memory of spatial relations between objects?

Munnich, Landau & Dosher (2001)

25 positionsMemory Task

Whorfian prediction: English speakers notice the difference more if it’s a touching position vs. a not-touching position since they linguistically encode this difference. Korean speakers will show no difference.

View 500 msec visual mask (500msec)

View 500msec

Same or different?

Munnich, Landau & Dosher (2001)

• Japanese/Korean speakers no worse than English speakers at noticing the difference.

• Whorfian prediction not upheld - language for spatial terms does not influence spatial memory.

Language and Thought

• No compelling evidence for the strong version of the Whorfian hypothesis – we can perceive the world independently of the language we use to describe the world

• But… language can sometimes influence some aspects of cognition (e.g. memory)