Language Part III

Language in Animals Language and Thought

Overview • Language in nonhumans

– Border collie – Alex the parrot – Kanzi / Nim chimpsky

• Language and thought

– Does language shape our perception? – 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”

• Chaser cam also recognize categories (“fetch a frisbee”)

• 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 (over 30

years) an extensive vocabulary of 50 words including color, number and shape terms, as well as relative concepts such as “bigger”, “smaller”

• 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_Wt8I Or 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

For an example of the lexigram: http://www.youtube.com/watch?v=wRM7vTrIIis&feature=relmfu

Video: Kanzi and novel sentences (2 min.)

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

Kanzi and Syntax / Reference • Some limited ability to understand novel sentences

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

• Does Kanzi have reference?

– “Banana” = “I want a banana to eat”, “Here is a picture of a banana”, “there is a picture of a banana”

Limitations of Bonobos and Chimps • Their language productions are quite limited

• Top 6 sentences produced by Nim Chimpsky (a chimpanzee) using

sign language: – Eat drink, eat drink – Eat Nim eat Nim – Banana Nim Banana Nim – Drink Nim Drink Nim – Banana eat me Nim – Banana me eat banana

• Longest utterance: “give orange me give eat orange me eat orange give

me eat orange give me you”

• Yang (2012): Nim’s productions not compatible with a combinatorial system

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 influences 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?

Experiment: participants place colored chips into specific categories

hue

brig

htne

ss

How English speakers tend to divide these up

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

English

Berinmo

(Davidoff 2001)

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 second delay

“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 table Kor/Jap: Ball table top-of [floating]

English: Ball on table Kor/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 positions Memory Task

Whorfian prediction: English speakers should notice the difference more if it’s a touching position vs. a not-touching position since they linguistically encode this difference. Korean speakers should 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)