- Ever thought Fido knows something you don't? Could he
even be laughing at you behind your back? It sounds like a joke, but the
joke could be on you. Recent studies appear to have isolated the noise
dogs make when they are amused or at play a sound which some researchers
say mirrors the human laugh.
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- Nevada researcher Patricia Simonet of Sierra Nevada College
in Lake Tahoe believes dogs make a specific noise during play that is distinctive
from other sounds made during passive or aggressive confrontation. Simonet
describes the sound as a breathy exhalation that sounds to a human ear
like a dog's regular panting. However, when the frequency of the "laugh"
was analysed, it was found to have a far broader range of frequencies than
a regular pant.
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- As part of the investigation, Simonet noted the behaviour
patterns of fifteen young dogs in an observation room. She broadcast recordings
of the "laugh-pant" that she had taken earlier, and found the
dogs reacted with excitement, often picking up a toy or approaching a presumed
playmate, if another dog or human was in the room. Even Simonet's own
attempts at emulating the sound prompted favourable reactions in the dogs,
causing them to move towards her in a playful way, looking for a romp.
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- Laughing at play
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- Simonet is not the first researcher to theorise on the
existence of animal laughter. Brian Knutson of the National Institutes
of Health in Maryland has recorded sounds made by laboratory rats as they
wrestle with one another. Apparently, the rats emit a distinct chirping
noise when wrestling in a playful manner, a sound that they repeat before
receiving morphine or having sex. Knutson suggests the sound is an expression
of pleasure - one the rats make when they know they are to be rewarded.
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- Knutson's rat studies have significant implications for
neuroscientists wanting to track the rodents' brains' reward circuitry.
But he believes there is still some way to go before scientists can accurately
measure how the rats' chirps compare to a guffaw or chuckle from a human.
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- Another analyst of rat chirps, Jaak Panskepp of Bowling
Green University, Ohio, goes one step further to suggest laughter, at least
in response to a direct physical stimulus such as tickling, may be a common
trait shared by all mammals. In order to record the sounds rats made sounds
of exceptionally high frequency Professor Panskepp placed a recording
device in the cage with the rats in his study, and proceeded to tickle
them gently around the nape of their necks. The rats soon began to emit
their high-pitched squeak even at the sight of the recording device, as
if in anticipation of being tickled. Panskepp noted, "the older animals
do not chirp as much as the younger ones but they still like it a lot and
they,ll follow your hand around and get all excited. This emotional response
that they,re showing is quite a primitive form of laughter that maybe all
mammals share."
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- Rats: Ticklish
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- Professor Robert R Provine also notes instances of perceived
laughter in chimpanzees in his book Laughter: A Scientific Investigation.
While studying the origins of the human laugh, Provine spent time tickling
and playing with young chimpanzees at the Yerkes Regional Primate Center
in Atlanta, Georgia. Provine discovered chimpanzees responded to pleasurable
stimulus in the same way as dogs by emitting a breathy, panting sound.
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- The studies have many implications for scientists wanting
to know more about how laughter is used as a form of communication, not
only in animals, but ultimately in humans. The initial research notes
that dogs usually restrict making their "laugh-pant" noise to
when they are around other dogs. This would indicate the sound is a communication
tool, allowing other dogs to pick up the mood of dogs around them. Like
humans, animal laughter appears to be infectious, with all dogs seeming
to respond to an initial burst of "dog laughter" with a mirrored
sound of their own.
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- So the next time you're making a joke about Fido's canine
antics, watch him closely. He could be having the last laugh.
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