Showing posts with label primate. Show all posts
Showing posts with label primate. Show all posts

Thursday, February 20, 2014

Monkey Mind Control

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Monkey Mind Control

The brain activity of one monkey dictated movements of a second, sedated animal, a study shows.
By  | February 19, 2014
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Rhesus monkeyFLICKR, SHANKAR S.Researchers have used two rhesus monkeys in an intriguing proof-of-principle experiment testing the ability to control a paralyzed body or limb. They used a machine to covert the brain activity of one monkey, called the master, into electrical impulses applied to the spinal cord of a sedated animal, called an avatar, which moved in response to the stimulation.
The results, published this week (February 17) inNature Communications, could provide insight for how thoughts might be translated into movement of paralyzed patients.
“This work in primates shows how this disconnection between brain and controlled movement could be overcome using brain machine interfaces that have the ability to identify the user’s intention or desire to perform a specific movement and, once identified, how this intended action can be translated through neural stimulation into the muscle activations that achieve the final goal of the movement,” biomedical engineer Bernard Conway of the University of Strathclyde said in a statement. “The work is a key step forward that demonstrates the potential of brain machine interfaces to be used in restoring purposeful movement to people affected by paralysis.”
The scientists, who hailed from Harvard Medical School, implanted a brain chip capable of monitoring 100 neurons into the master monkey, recorded the cells’ electrical activity during training, and then matched the patterns of neural activity with the physical actions of the monkey. The researchers also implanted 36 electrodes in the spinal cord of the avatar monkey, then tested how the activation of the electrodes could elicit different movements from the animal.
Finally, the team connected the two monkeys to each other, such that the activity being recorded from the master’s brain controlled the movements of the avatar in real time. The master was to control the movement of a cursor using a joystick held by the avatar, and, 98 percent of the time, it succeeded.
“The goal is to take people with brain stem or spinal cord paralysis and bypass the injury,” Ziv Williams, told BBC News. “The hope is ultimately to get completely natural movement, I think it’s theoretically possible, but it will require an exponential additional effort to get to that point.”
“Whilst the control of limbs is sophisticated, it is still rather crude overall,” Christopher James of the University of Warwick agreed in a statement. Additionally, increased muscle rigidity following paralysis, as well as changes in blood pressure, pose challenges for restoring precise control.
Nevertheless, James said that the implications of the new research were profound, “especially for controlling limbs in spinal cord injury, or controlling prosthetic limbs with limb amputees.”

Wednesday, November 13, 2013

Monkeys 'understand' rules underlying language musicality

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13-Nov-2013
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Contact: Andrea Ravignani
andrea.ravignani@univie.ac.at
43-142-777-6101
University of Vienna 

Monkeys 'understand' rules underlying language musicality

This news release is available in German.
 IMAGE: This is Andrea Ravignani, Ph.D. candidate at the Department of Cognitive Biology at the University of Vienna.
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Many of us have mixed feelings when remembering painful lessons in German or Latin grammar in school. Languages feature a large number of complex rules and patterns: using them correctly makes the difference between something which "sounds good", and something which does not. However, cognitive biologists at the University of Vienna have shown that sensitivity to very simple structural and melodic patterns does not require much learning, or even being human: South American squirrel monkeys can do it, too.
Language and music are structured systems, featuring particular relationships between syllables, words and musical notes. For instance, implicit knowledge of the musical and grammatical patterns of our language makes us notice right away whether a speaker is native or not. Similarly, the perceived musicality of some languages results from dependency relations between vowels within a word. In Turkish, for example, the last syllable in words like "kaplanlar" or "güller" must "harmonize" with the previous vowels. (Try it yourself: "güllar" requires more movement and does not sound as good as "güller".)
Similar "dependencies" between words, syllables or musical notes can be found in languages and musical cultures around the world. The biological question is whether the ability to process dependencies evolved in human cognition along with human language, or is rather a more general skill, also present in other animal species who lack language.
 IMAGE: This is a Squirrel monkey/Saimiri sciureus.
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Andrea Ravignani, a PhD candidate at the Department of Cognitive Biology at the University of Vienna, and his colleagues looked for this "dependency detection" ability in squirrel monkeys, small arboreal primates living in Central and South America. Inspired by the monkeys' natural calls and hearing predispositions, the researchers designed a sort of "musical system" for monkeys. These "musical patterns" had overall acoustic features similar to monkeys' calls, while their structural features mimicked syntactic or phonological patterns like those found in Turkish and many human languages.
Monkeys were first presented with "phrases" containing structural dependencies, and later tested using stimuli either with or without dependencies. Their reactions were measured using the "violation of expectations" paradigm. "Show up at work in your pyjamas, people will turn around and stare at you, while at a slumber party nobody will notice", explains Ravignani: In other words, one looks longer at something that breaks the "standard" pattern. "This is not about absolute perception, rather how something is categorized and contrasted within a broader system." Using this paradigm, the scientists found that monkeys reacted more to the "ungrammatical" patterns, demonstrating perception of dependencies. "This kind of experiment is usually done by presenting monkeys with human speech: Designing species-specific, music-like stimuli may have helped the squirrel monkeys' perception", argues primatologist and co-author Ruth Sonnweber.
"Our ancestors may have already acquired this simple dependency-detection ability some 30 million years ago, and modern humans would thus share it with many other living primates. Mastering basic phonological patterns and syntactic rules is not an issue for squirrel monkeys: the bar for human uniqueness has to be raised", says Ravignani: "This is only a tiny step: we will keep working hard to unveil the evolutionary origins and potential connections between language and music".
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The research was funded by an ERC Advanced Grant, SOMACCA, to Prof. Tecumseh Fitch, which is exploring the broad biological basis for music, language, and visual art.
Publication in "Biology Letters":


Ravignani A, Sonnweber R-S, Stobbe N, Fitch WT. 2013 Action at a distance: dependency sensitivity in a New World primate. Biol Lett 20130852.http://dx.doi.org/10.1098/rsbl.2013.0852




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