Religions > Atheism > 'Uniquely human' component of language found in gregarious birds
| Topic: |
Religions > Atheism |
| User: |
"johac" |
| Date: |
28 Apr 2006 01:59:54 AM |
| Object: |
'Uniquely human' component of language found in gregarious birds |
"Yo! Who you callin' birdbrain?"
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University of Chicago Medical Center
'Uniquely human' component of language found in gregarious birds
Although linguists have argued that certain patterns of language
organization are the exclusive province of humans -- perhaps the only
uniquely human component of language -- researchers from the University
of Chicago and the University of California San Diego have discovered
the same capacity to recognize such patterns and distinguish between
them in Sturnus vulgaris, the common European starling.
In the April 27, 2006, issue of Nature, the researchers show that these
starlings long known as virtuoso songbirds and expert mimics can be
trained to reliably discriminate between two different patterns of
organizing the sounds they use to communicate.
"Our research is a refutation of the canonical position that what makes
human language unique is a singular ability to comprehend these kinds of
patterns," said Timothy Gentner, assistant professor of psychology at
UCSD and lead author of the study. "If birds can learn these patterning
rules, then their use does not explain the uniqueness of human language."
The researchers focused on recursion, or center-embedding, a
characteristic, found in all human languages. Recursion is one way of
creating of new and grammatically correct meanings by inserting words
and clauses within sentences -- theoretically, without limit. So, for
example, "The bird sang," can become "The bird the cat chased sang."
Following the lead of language theorist Noam Chomsky, linguists have
held that this recursive center-embedding is a universal feature of
human language and, moreover, that the ability to process it forms a
unique computational ability important for human language.
"Linguists have developed a mathematically rigorous set of definitions,
a hierarchy of syntactical complexity, that governs the process of how
humans create and understand utterances," said Daniel Margoliash,
professor of anatomy and organismal biology at the University of Chicago
and co-author of the study. "These rules govern how to properly express
yourself how to structure your phrases and sentences.
Language experts have used properties of these rules, whose complexity
is described by the Chomsky hierarchy, "to define the boundaries between
humans and other creatures," said Margoliash. "Now we find that we have
been joined on this side of that boundary by the starling. It should no
longer be considered an insult to be called a bird brain."
Although they are not known for the lilting beauty of their songs,
starlings produce an amazing array of complex sounds, combining chirps,
warbles, trills and whistles with rattling sounds.
They also have a talent for mimicry. One starling famously copied an
unpublished tune that Mozart whistled in a pet store; the composer
purchased the bird and kept it as a pet. The starling is mentioned only
once in all of Shakespeare, but in that passage an angry warrior,
forbidden by the King to speak of a rival, Mortimer, decides he will
"have a starling shall be taught to speak nothing but 'Mortimer,' and
give it him to keep his anger still in motion." (Because of this
passage, 100 European starlings were first introduced to New York City's
Central Park in the 1890s. They flourished. North America now has an
estimated 200 million starlings.)
One previous study, however, suggested that even non-human primates are
incapable of recognizing anything beyond the simplest syntax. A paper
published in Science in 2004 by scientists at Harvard and MIT found that
cotton-top tamarin monkeys were not able to master higher-level grammar
patterns. "The acquisition of hierarchical processing ability," the
authors of that paper conclude, "may have represented a critical
juncture in the evolution of the human language faculty." They also
noted that vocal learners, such as songbirds, might have produced
different results.
"When I saw that study I was not convinced of the significance of the
failure of the monkeys," said Howard Nusbaum, chairman and professor of
psychology at the University of Chicago and senior author of the Nature
study. "There are many ways for an experiment to fail and most failures
are not scientifically interesting. I immediately thought: we could do
that in starlings."
Nusbaum, Margoliash and psychologist Kimberly Fenn had previously
collaborated on studies of the role of sleep in speech perceptual
learning. Gentner, a neuropsychologist, expert on starlings and, at the
time, a postdoctoral fellow at the University of Chicago, was an
essential addition.
To assess the birds' syntactical skills, the research team exploited the
diverse sounds in starling songs. They recorded eight different
'rattles' and eight 'warbles' from a single male starling and combined
them to construct a total of 16 artificial songs. These songs followed
two different grammars, or patterning rules.
Eight songs followed the "finite-state" rule, the simplest sort, thought
to account for all non-human communication. A finite-state grammar
allows for sounds to be appended only at the beginning or end of a
string. These songs were built up from a rattle-warble base by adding
rattle-warble pairs at the end. The simplest song (ab) was one rattle
followed by one warble. The next simplest a rattle, then a warble,
followed by a different Rattle and Warble (abAB).
The other eight songs followed the "context-free" rule, which allows for
sounds to be inserted in the middle of an acoustic string, the simplest
form of recursive center-embedding. So a context-free sequence also
began with rattle-warble base (ab) but built up by inserting new sounds
in the middle, such as rattle-Rattle-Warble-warble (aABb).
Eleven adult birds were given lessons on distinguishing between these
two sets of songs using classic reinforcement techniques. The birds were
rewarded with food when they heard a song from the context-free set and
for refraining when they heard one from the finite-state set.
After 10,000 to 50,000 trials over several months, 9 of 11 tested
starlings learned to distinguish the patterns. The birds were not simply
memorizing particular sequences of rattles and warbles they could
distinguish between different patterns even when presented with entirely
new sequences of rattles and warbles. They were applying rules to solve
the task.
The researchers also checked to see how the birds responded to
"ungrammatical" strings, songs that violated the established rules. The
starlings treated these differently, as expected if they had learned the
patterns.
The experimenters then asked if the birds were capable of a key feature
of human grammars. Could the starlings extrapolate these patterning
rules to distinguish among longer strings? Remarkably, after learning
the patterns with shorter songs made up of two pairs of rattles and
warbles, the birds were able to recognize strings containing 6-to-8 song
elements (abababab vs aaaabbbb).
The finding that starlings can grasp these grammatical rules shows that
other animals share basic levels of pattern recognition with humans.
"There might be no single property or processing capacity," the authors
write, "that marks the many ways in which the complexity and detail of
human language differs from non-human communication systems."
"It may be more useful," they add, "to consider species differences as
quantitative rather than qualitative distinctions in cognitive
mechanisms."
"The more closely we understand what non-human animals are capable of,"
Gentner said, "the richer our world becomes. Fifty years ago, it was
taboo to even talk about animal cognition. Now, no one doubts that
animals have complex and vibrant mental lives."
"When I describe our results to linguists and psycholinguists, they are
amazed," Nusbaum said. "When I mention them to people who study animal
behavior," Margoliash countered, "they are not surprised. They are well
aware of the cognitive abilities of many animals."
"These birds are a lot smarter than you might think," Margoliash said.
"They have innate abilities. They solve interesting problems and learn
difficult tasks. Any number of times during the experiments I said 'they
can't possibly do that,' and they did."
"There has long been a temptation," writes cognitive neuroscientist Gary
Marcus of New York University in a commentary, "to sum up the
differences between human and other species in a neat turn of phrase
but most posited differences turn out to have been overstated."
But these iridescent six-inch, three-ounce singing black birds have
known this all their lives. They were only waiting for this moment to
arise.
---
http://www.eurekalert.org/pub_releases/2006-04/uocm-hc042406.php
--
John Hachmann aa #1782
"Those who can make you believe absurdities can make you commit atrocities"
-Voltaire
Contact - Throw a .net over the .com
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| User: "stoney" |
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| Title: Re: 'Uniquely human' component of language found in gregarious birds |
01 May 2006 05:45:10 PM |
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On Thu, 27 Apr 2006 23:59:54 -0700, johac <jhachmann@sbcglobal.com>
wrote in alt.atheism
"Yo! Who you callin' birdbrain?"
---
University of Chicago Medical Center
'Uniquely human' component of language found in gregarious birds
Cool!
[]
--
Fundies and trolls are cordially invited to
shove a wooden cross up their arses and rotate
at a high rate of speed. I trust you'll
be 'blessed' with a plethora of splinters.
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