Language Part III
Language in Animals
Language 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_Wt8I
Or http://www.youtube.com/watch?v=7yGOgs_UlEc
Non-human primates
sarah & co.
washoe
washoe & louslis
vicki
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?
brightness
Range of Color: Maunsell color chips
hue
How English speakers tend to divide these up
How members from the Berinmo tribe (New Guinea) divide the colors
Berinmo
English
(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
Within category
Across category
Across category
Within category
(Davidoff 2001)
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.
Study
30 second
delay
Test
“nol”
“nol”
“wor”
“nol”
Roberson & Davidoff (2000)
Results on Recognition Memory Task
• English speakers showed better performance for targets
from across-category pairs than for those from withincategory 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)
Results
Red squares = Between
category identification
Blue diamonds = Within
category identification
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.
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
Same or
different?
View 500 msec
visual mask
(500msec)
View 500msec
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.
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)