Thursday, May 16, 2013
Motor control for speech versus non-speech vocal tract gestures
Here is a pretty cool demo from the 1960s showing the dissociability of motor control during speech versus non-speech tongue movements. Check it out! Thanks to Ron Nutsell for pointing this out.
Thursday, May 9, 2013
Flying Pigs on National Public Radio: Promoting the wrong theory of language and understanding
NPR aired an interview recently with Benjamin Bergen, UCSD cognitive scientist, discussing an embodied view of word meaning. The basic idea is nothing new by now: we understand words by "simulating" our physical experiences that have become associated with those words. Here's a quote taken from the NPR transcript of the interview:
This is standard embodied cognition speak. I haven't read his book, but this view seems to be the central topic of Bergen's monograph, Louder than words: the new science of how the brain makes meaning. I'm sure his book is much more careful and articulated than the interview, but the interview is what more people will hear and so deserves a response, particularly because the interview discussion goes beyond word meanings, claiming to reset our understanding of language itself:
He then goes to explain how we understand language via simulation, as in the baseball example. This generalization to language is troubling, reckless even. There are so many problems with the claim, it's hard to know where to start, but I'll try:
1. A theory of word meaning is not a theory of language, it's a theory of word meaning. Let's translate the argument to the visual domain to reveal how ridiculous this generalization is. "Just a few decades ago, many visual scientists used to think that the human brain has evolved special modules for vision, like systems for wavelength frequency detection, motion detection, and analysis of object form. But in the 1990s MRI technology let them watch the brain respond to visual scenes. And what they saw didn't look like a module, but involved activation all over the brain." Do we conclude that decades of research on vision got it all wrong just because lot's of brain tissues lights up when we look at things? Of course not! Bergen's comment is nothing more than a misguided interpretation of functional MRI and its relation to computational systems in the brain.
2. To push the point, it's not even clear to me that Bergen's theory has anything to do with language. It is a theory of conceptual representation, not a theory of how the brain takes an acoustic signal and extracts and transforms the relevant bits to make contact with that conceptual system. The latter issue is what occupies most linguists' time and theoretical focus. Does Bergen claim that his theory explains cochlear filtering of the acoustic signal. No. Does he claim that his theory explains how that signal is elaborated in the frequency and time domains to yield a spectro-temporal representation of the signal? No. Does he claim that the theory explains how that spectro-temporal signal makes contact with representations of word forms in the listener? No. Does visual simulation of the events described in the sentence explain the word order in the sentence? Or the position and use of words like the and to in that sentence? No, those are the kinds of things that perceptual scientists and linguists worry about: the transformation of the acoustic signal into some format that will allow contact with meaning and Bergen's simulation theory has nothing to say about it, which means that it has nothing to say about the "module for language" that many linguists used to believe in. Moral: don't claim to have solved puzzle A when you are fiddling with the pieces of puzzle B.
3. Simulation theories of conceptual representation don't solve any problems. Let's consider Bergen's theory: we understand the sentence "the shortstop threw the ball to first base" by simulating what it would be like to see the action and by simulating what it would be like to do the action. And, he argues elsewhere, we understand things we have never seen or done by combining or generalizing from things we have seen and done. So "flying pig" is understood by combining the experienced concepts of FLY (as seen with birds) with that of PIG. The result is the visual activation of the image of a pig with wings, which is the neural basis of our understanding. But wait, Bergen said that the way we understand action (flying is an action) is by simulating it in our visual system and by doing it with our motor system. It's not clear how we can simulate FLYING PIG in our motor system, so the motor part must not be critical in this case, which makes us question whether it is critical in the shortstop throwing a ball case. (Good thing we have a reason to question the motor part, because then we have an explanation for why quadraplegic individuals can enjoy baseball as much as the rest of us.) So, we must conclude, simulation of the perceptual bit is where our understanding of "flying pig" comes from. But now I'm confused. How do we know which perceptual experience to simulate? Do I combine my experience with pigs and birds and give the hybrid creature wings? Or do I combine pig with superman and give it a cape (a possibility noted in the interview)? Or maybe I combine pig with my experience flying on 737s and imagine a pig sitting in coach ordering a Diet Coke. Or should I combine pig with my baseball experiences and picture a mini pig being used as a baseball and getting smacked out to center field. Maybe, an embodied theorist might claim, that's the cool part: depending on which experiences I combine, I get a different meaning. Fine, but let's flip it around. How do I know that a pig with wings, a pig in coach, and a ball-shaped pig, one flapping, one sitting and sipping, and one hurtling through space are all examples of flying pigs? What is telling me that each of those simulations are linked? You might say that they are linked due to similarity of experience. By what metric? My perceptual experiences with each of these kinds of FLYING are wildly different. How does the brain know to associate them? Something must be telling the system that those instances are "similar" in the relevant respects. Now we need a theory of that! Here's the point: simulating a specific experience of say FLY can't be enough because it doesn't capture our ability to generalize the meaning to birds, planes, and baseballs. We have to be "simulating" something more abstract such that it captures those generalizations; and if we are "simulating" an abstract something, we might as well call it an abstract representation just like in "classical" theories. Saying that we understand by "simulation" just relabels the problem, it doesn't solve anything.
I'm sure we could go on but I think I'll just conclude instead: Bergen's theory is not about language so whatever claims that are made on that front are just hyperbole. And in the domain that the theory actually applies, it doesn't improve our understanding.
If someone read a sentence like, "the shortstop threw the ball to first base," parts of the brain dedicated to vision and movement would light up, Bergen says. "The question was, why?" he says. "They're just listening to language. Why would they be preparing to act? Why would they be thinking that they were seeing something?"
The answer that emerged from this research is that when you encounter words describing a particular action, your brain simulates the experience, Bergen says.
"The way that you understand an action is by recreating in your vision system what it would look like to perceive that event and recreating in your motor system what it would be like to be that shortstop, to have the ball in your hand and release it," Bergen says.
Just a few decades ago, many linguists thought the human brain had evolved special module for language. It seemed plausible that our brains have some unique structure or system. After all, no animal can use language the way people can.
But in the 1990s, scientists began testing the language-module theory using "functional" MRI technology that let them watch the brain respond to words. And what they saw didn't look like a module, says Benjamin Bergen.
They found something totally surprising," Bergen says. "It's not just certain specific little regions in the brain, regions dedicated to language, that were lighting up. It was kind of a whole-brain type of process.
He then goes to explain how we understand language via simulation, as in the baseball example. This generalization to language is troubling, reckless even. There are so many problems with the claim, it's hard to know where to start, but I'll try:
1. A theory of word meaning is not a theory of language, it's a theory of word meaning. Let's translate the argument to the visual domain to reveal how ridiculous this generalization is. "Just a few decades ago, many visual scientists used to think that the human brain has evolved special modules for vision, like systems for wavelength frequency detection, motion detection, and analysis of object form. But in the 1990s MRI technology let them watch the brain respond to visual scenes. And what they saw didn't look like a module, but involved activation all over the brain." Do we conclude that decades of research on vision got it all wrong just because lot's of brain tissues lights up when we look at things? Of course not! Bergen's comment is nothing more than a misguided interpretation of functional MRI and its relation to computational systems in the brain.
2. To push the point, it's not even clear to me that Bergen's theory has anything to do with language. It is a theory of conceptual representation, not a theory of how the brain takes an acoustic signal and extracts and transforms the relevant bits to make contact with that conceptual system. The latter issue is what occupies most linguists' time and theoretical focus. Does Bergen claim that his theory explains cochlear filtering of the acoustic signal. No. Does he claim that his theory explains how that signal is elaborated in the frequency and time domains to yield a spectro-temporal representation of the signal? No. Does he claim that the theory explains how that spectro-temporal signal makes contact with representations of word forms in the listener? No. Does visual simulation of the events described in the sentence explain the word order in the sentence? Or the position and use of words like the and to in that sentence? No, those are the kinds of things that perceptual scientists and linguists worry about: the transformation of the acoustic signal into some format that will allow contact with meaning and Bergen's simulation theory has nothing to say about it, which means that it has nothing to say about the "module for language" that many linguists used to believe in. Moral: don't claim to have solved puzzle A when you are fiddling with the pieces of puzzle B.
3. Simulation theories of conceptual representation don't solve any problems. Let's consider Bergen's theory: we understand the sentence "the shortstop threw the ball to first base" by simulating what it would be like to see the action and by simulating what it would be like to do the action. And, he argues elsewhere, we understand things we have never seen or done by combining or generalizing from things we have seen and done. So "flying pig" is understood by combining the experienced concepts of FLY (as seen with birds) with that of PIG. The result is the visual activation of the image of a pig with wings, which is the neural basis of our understanding. But wait, Bergen said that the way we understand action (flying is an action) is by simulating it in our visual system and by doing it with our motor system. It's not clear how we can simulate FLYING PIG in our motor system, so the motor part must not be critical in this case, which makes us question whether it is critical in the shortstop throwing a ball case. (Good thing we have a reason to question the motor part, because then we have an explanation for why quadraplegic individuals can enjoy baseball as much as the rest of us.) So, we must conclude, simulation of the perceptual bit is where our understanding of "flying pig" comes from. But now I'm confused. How do we know which perceptual experience to simulate? Do I combine my experience with pigs and birds and give the hybrid creature wings? Or do I combine pig with superman and give it a cape (a possibility noted in the interview)? Or maybe I combine pig with my experience flying on 737s and imagine a pig sitting in coach ordering a Diet Coke. Or should I combine pig with my baseball experiences and picture a mini pig being used as a baseball and getting smacked out to center field. Maybe, an embodied theorist might claim, that's the cool part: depending on which experiences I combine, I get a different meaning. Fine, but let's flip it around. How do I know that a pig with wings, a pig in coach, and a ball-shaped pig, one flapping, one sitting and sipping, and one hurtling through space are all examples of flying pigs? What is telling me that each of those simulations are linked? You might say that they are linked due to similarity of experience. By what metric? My perceptual experiences with each of these kinds of FLYING are wildly different. How does the brain know to associate them? Something must be telling the system that those instances are "similar" in the relevant respects. Now we need a theory of that! Here's the point: simulating a specific experience of say FLY can't be enough because it doesn't capture our ability to generalize the meaning to birds, planes, and baseballs. We have to be "simulating" something more abstract such that it captures those generalizations; and if we are "simulating" an abstract something, we might as well call it an abstract representation just like in "classical" theories. Saying that we understand by "simulation" just relabels the problem, it doesn't solve anything.
I'm sure we could go on but I think I'll just conclude instead: Bergen's theory is not about language so whatever claims that are made on that front are just hyperbole. And in the domain that the theory actually applies, it doesn't improve our understanding.
Thursday, May 2, 2013
Post Doctoral Position - Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig (Obleser lab)
The Max Planck Institute for Human Cognitive and Brain Sciences (MPI CBS) in Leipzig and the Max Planck Research Group “Auditory Cognition” (headed by Jonas Obleser) are now offering a Postdoctoral researcher position, for initially 2 years, preferably starting by October 2013.
Successful candidates will have a PhD in cognitive neuroscience, psychology, or natural sciences. Prior experience with either fMRI or EEG/MEG methods is expected, and an interest in further applying and combining both domains in their research is highly desirable. Candidates with a background and/or interest in advanced fMRI methods are particularly encouraged to apply.
The successful candidate will share our enthusiasm in problems of auditory cognition and auditory neuroscience, and ideally has already demonstrated this by contributing to the field. However, researchers with a background in visual or other neuroscience are also encouraged to apply. He or she should have a solid methods background and strong methods interest, hands-on experience in problems of data and statistical analysis, and the interest to co-supervise the PhD and Master students in the group. The position offered does not include any teaching obligations.
Starting date is flexible. Salary is dependent on experience and based on MPI stipends or equivalent salary according to German Public service regulations.
The research will be conducted at the MPI CBS in Leipzig, Germany, an internationally leading centre for cognitive and imaging neuroscience equipped with a 7.0 T MRI scanner, three 3.0 T MRI scanners, a 306 channels MEG system, a TMS system and several EEG suites. All facilities are supported by experienced IT and physics staff. Our institute (just 190 km, or 70 minutes by train, south of Berlin) offers a very international environment, with English being the language spoken in the laboratory. It offers a friendly and generous environment of researchers with diverse backgrounds and with an excellent infrastructure.
In order to increase the proportion of female staff members, applications from female scientists are particularly encouraged. Preference will be given to disabled persons with the same qualification.
Applications should be kindly sent to personal@cbs.mpg.de using the application code “PD 03/2013” in the subject. Please send your application as a single pdf attachment, with the file name containing your surname. It should enclose a cover letter (max. 2 pages) that also specifies your future research interests; a CV; up to three representative reprints; and contact details of 2 personal references. This call remains open until the position is filled.
For further details please contact Dr Jonas Obleser, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany, obleser@cbs.mpg.de
Tuesday, April 16, 2013
What is language?
Daniel Everett recently gave a talk on his language-as-a-cultural-tool idea at our UC Irvine Center for Language Science. (Here's a decent review of his recent book.) It was an entertaining talk but misses the point, in my view, regarding what language really is.
Today I'm reading a very nice review paper by Agnes Roby-Brami and colleagues on the relation between language and praxis (suggested by a sage reviewer of a submitted paper of mine). It's worth a look. Very informative and scholarly, but that's not what I want to talk about here. Instead I want to focus on their definition of language:
But back to signs: how does the notion of language as a system of signs tilt the playing field toward a language as culture viewpoint? It does so by focusing on the arbitrary aspects of language, those aspects that most closely related to "cultural conventions"; things like words.
It's not the signs that define language. To see this, think about Roby-Brami and colleague's definition in visual terms:
Of course you are right. But we can easily think of vision as social if we misconstrue it. Take any number of your modern objects and show them to a member of a hunter-gatherer society. Take your iPhone, you coffee maker, your bicycle, your eyeglasses, your credit card, your zipper, your whatever. They will have no idea what those objects are. These "object-signs" have no meaning to them. We know what they are only because we have learned the object-signs through cultural experience. It's as if we are "speaking" different visual languages! Therefore, we should conclude, vision is a cultural system.
We can see the flaw in *that* argument, of course. What vision takes as input and what previous associates we have with particular objects and their uses doesn't define the perceptual/perceptual-motor system. What defines vision are the computations that are used to extract form, motion, and location and associates these with higher-order conceptual systems, motor systems, and so on.
Why can't we see that the same flaw holds in the language argument? The "word-signs" with their culturally agreed on meanings don't define language. What defines language are the computations that are used to extract sound patterns from acoustic babble, to segment them, to combine them, and ultimately link them to complex conceptual representations or to motor speech gestures.
Today I'm reading a very nice review paper by Agnes Roby-Brami and colleagues on the relation between language and praxis (suggested by a sage reviewer of a submitted paper of mine). It's worth a look. Very informative and scholarly, but that's not what I want to talk about here. Instead I want to focus on their definition of language:
Language refers to a system of signs (indices, icons, symbols) used to encode and decode information so that the pairing of a specific sign with an intended meaning is established through social conventions.This definition is exactly the kind of conception about language that lends itself to Everettesque monologues about language as culture. Yes, yes culture is reflected through language, but it doesn't mean that language IS culture.
But back to signs: how does the notion of language as a system of signs tilt the playing field toward a language as culture viewpoint? It does so by focusing on the arbitrary aspects of language, those aspects that most closely related to "cultural conventions"; things like words.
It's not the signs that define language. To see this, think about Roby-Brami and colleague's definition in visual terms:
Vision refers to a system of objects (forms, movements, and so on) that contain information so that the pairing of a specific object with its associated meaning is established through social conventions.What?! Vision isn't a social convention, you say. It's a neural system that analyzes visual form, motion, and location to transform physical information into conceptual representations or into motor patterns for interacting with those objects. Vision is NOT in the objects themselves!
Of course you are right. But we can easily think of vision as social if we misconstrue it. Take any number of your modern objects and show them to a member of a hunter-gatherer society. Take your iPhone, you coffee maker, your bicycle, your eyeglasses, your credit card, your zipper, your whatever. They will have no idea what those objects are. These "object-signs" have no meaning to them. We know what they are only because we have learned the object-signs through cultural experience. It's as if we are "speaking" different visual languages! Therefore, we should conclude, vision is a cultural system.
We can see the flaw in *that* argument, of course. What vision takes as input and what previous associates we have with particular objects and their uses doesn't define the perceptual/perceptual-motor system. What defines vision are the computations that are used to extract form, motion, and location and associates these with higher-order conceptual systems, motor systems, and so on.
Why can't we see that the same flaw holds in the language argument? The "word-signs" with their culturally agreed on meanings don't define language. What defines language are the computations that are used to extract sound patterns from acoustic babble, to segment them, to combine them, and ultimately link them to complex conceptual representations or to motor speech gestures.
Friday, March 22, 2013
RTs: One-voxel neuroimaging?
Yes! says Brad Buchsbaum in an entertaining and thought provoking post on his flowbrain blog. Check out the post here.
Monday, March 18, 2013
Postdoctoral position -- MRC Cognition and Brain Sciences Unit, Cambridge, UK
Career Development Fellow (Postdoctoral position)
The MRC Cognition and Brain Sciences Unit (CBSU) is an internationally renowned research institute with state-of-the-art cognitive neuroscience facilities, including a research dedicated 3T Siemens Trio MRI scanner and 306-channel Elekta Neuromag MEG system.
Applications are invited for a post-doctoral position to work within a research programme led by Dr Matthew Davis investigating neural systems for perceiving, understanding and learning spoken language. The research will use advanced functional imaging methods (fMRI, MEG/EEG) to explore speech processing in healthy, adult participants. Additional opportunities may arise to work with children or adults with language impairment.
You should have, or be in the final stages of obtaining, a PhD in cognitive neuroscience or related field, including experience of one or more neuroimaging methods. A strong computational or statistical background is desirable and experience of speech signal processing or psycholinguistics.
This is a three year training and development postdoctoral position. The starting salary will be in the range of £26,022 - £29,324 per annum, depending upon qualifications and experience. We offer a flexible pay and reward policy, 30 days annual leave entitlement, and an optional MRC final salary Pension Scheme. On site car and bicycle parking is available.
For informal enquiries, contact Matt Davis by email: matt.davis@mrc-cbu.cam.ac.uk.
Applications are handled by the RCUK Shared Services Centre; for further information and to apply please visit our job board, by following this link, including the IRC86470 reference. Closing date: 9th April 2013
Thursday, March 14, 2013
FIVE POST-BAC RESEARCH POSITIONS AT THE UNIVERSITY OF MARYLAND
The Dept of Linguistics at the U of Maryland, is looking to fill up to five full-time positions for post-baccalaureate researchers. Starting date for all positions is Summer/Fall 2013. Salary is competitive, with benefits included. The positions would be ideal for individuals with a BA degree who are interested in gaining significant research experience in a very active lab as preparation for a research career. Applicants must be US or Canadian citizens or permanent residents, and should have completed a BA or BS degree by the time of appointment. The ability to interact comfortably with a wide variety of people (and machines) is a distinct advantage. Applicants may request to be considered for all five positions.
The positions are open until filled, but for best consideration, applications should be received by April 5th. Details at http://ling.umd.edu/baggett/jobs/
Positions #1-#2: Baggett Research Fellowships
Baggett Fellowships are full-time positions. Fellows can pursue research in linguistics, cognitive (neuro-)science of language, language acquisition, or computational modeling. 1-2 positions are available for 2013-2014. Positions are for one year and are not renewable. Contact person: Dr Andrea Zukowski (address below). For further details, including the faculty mentor list:
Position #3: Research Assistant in Psycholinguistics/Cognitive Neuroscience
This person will be involved in all aspects of studies of language comprehension using behavioral and neuroscientific techniques, including electrophysiological brain recordings (training provided). The person will also contribute to Maryland's IGERT training program in Language Science, (languagescience.umd.edu). Previous experience in (psycho-)linguistics preferred. 1 year initial appointment, possibility of extension. Contact Dr. Colin Phillips (address below). Application requirements same as for Baggett Fellowships.
Position #4: Research Assistant in Psycholinguistics/Cognitive Neuroscience
This person will have the opportunity to be involved in a variety of projects examining language comprehension with behavioral and neurophysiological recording methods including ERP, MEG, and fMRI (training provided). Previous experience in linguistics and/or language processing is preferred; reasonable comfort with basic programming and statistics is a significant plus. 1 year initial appointment with possibility of extension. Contact person: Dr. Ellen Lau (address below). Application requirements same as for Baggett Fellowships.
Position #5: MEG Laboratory Manager
This person will play a leading role in the operation of a magnetoencephalography (MEG) facility that is managed jointly by the Dept. of Linguistics and the Maryland Neuroimaging Center, and serves researchers from many departments, for studies on language, vision, memory, reading, audition, and kinesiology. The person will be trained as an expert user of the facility, will help to guide and train other users, will coordinate and enhance resources for the experimental paradigms in use in the lab, and will manage the smooth daily operation of the lab. The person will also have opportunities to participate in and/or lead research projects, and participate in a range of other intellectual activities in language and cognitive neuroscience. Previous laboratory experience is preferred, and the ability to interact comfortably with a wide variety of people and technologies is strongly preferred. Prior experience with MEG or other electrophysiological techniques is NOT required. The position is for a one year initial appointment, with the possibility of extension beyond that time. For more information contact lab co-directors Dr. Ellen Lau (Linguistics; address below). Application requirements are the same as for the Baggett Fellowships.
Applicants may request to be considered for all five positions, or any subset. Applicants for any of these positions should submit a cover letter outlining relevant background and interests, including potential faculty mentors (multiple mentors are possible), a current CV, and names and contact information for 3 potential referees. Reference letters are not needed as part of the initial application. Applicants should also send a writing sample. All application materials should be submitted electronically to the following recipients:
Positions #1-#2 - Andrea Zukowski (zukowski at umd.edu). Put 'Baggett Fellowship' in the subject line.
Position #3 - Colin Phillips (colin at umd.edu). Put 'Research Assistantship' in the subject line.
Position #4 - Ellen Lau (ellenlau at umd.edu). Put 'Research Assistantship' in the subject line.
Position #5 - Ellen Lau (ellenlau at umd.edu). Put 'MEG Lab Manager' in the subject line.
The Dept of Linguistics has shared facilities for testing of infants, children and adults, 2 eye-tracking labs, an ERP lab and a whole-head MEG facility. The department is part of a vibrant language science community that numbers 200 faculty, researchers, and graduate students across 10 departments, and is affiliated with the Neuroscience and Cognitive Science Program and the new Maryland Neuroimaging Center.
Best Consideration for Applications: 5-Apr-2013
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