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News and views on the neural organization of language

Greg Hickok
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  • August 18, 2011
  • 03:00 PM

Mirror Neuron Forum - some additional discussion - Part II

by Greg Hickok in Talking Brains

In my answer to Question 1 I suggested that mirror neurons can be viewed analogously to canonical neurons, that is, as a sensory-motor association system involved in action selection, not action understanding. Here is Gallese's response to this suggestion:

According to GH, both classes of neurons instantiate the action-oriented coding typical of the dorsal stream, whereas object and action semantics would be exclusively provided by the ventral stream. However, an exclu- sive action-oriented ch........ Read more »

Gallese, V., Gernsbacher, M., Heyes, C., Hickok, G., & Iacoboni, M. (2011) Mirror Neuron Forum. Perspectives on Psychological Science, 6(4), 369-407. DOI: 10.1177/1745691611413392  

  • August 16, 2011
  • 08:27 PM

Mirror Neuron Forum - Some additional discussion - Part I

by Greg Hickok in Talking Brains

Now that people have had a chance to digest the recently published "Mirror Neuron Forum" (Perspectives on Psychological Science 6(4) 369–407) I think it would be useful to revisit some of the claims and counter-claims. I will start working through some of the points in a series of posts. Of course, my focus will be on the parts of the forum that I participated in, but if you have some comments and thoughts on any part of it, feel free to email me and I'll post it as "guest post".

I would li........ Read more »

Gallese V, & Goldman A. (1998) Mirror neurons and the simulation theory of mind-reading. Trends in cognitive sciences, 2(12), 493-501. PMID: 21227300  

  • June 10, 2011
  • 10:54 PM

Movement goals and feedback control in speech production

by Greg Hickok in Talking Brains

I just finished reading an excellent review article by Joseph Perkell, titled Movement goals and feedback and feedforward control mechanisms in speech production. If you want a nice survey of behavioral speech production research from the motor control perspective (as opposed to the psycholinguistic perspective), this should definitely be on your reading list. In the review, Perkell argues a few different points. One is that the goals, or targets, of speech production are sensory. I agree co........ Read more »

  • May 18, 2011
  • 07:17 PM

Two new ways the mirror system claim is losing steam

by Greg Hickok in Talking Brains

Next week Giacomo Rizzolatti will give the Keynote Address at the 23rd annual meeting of the Association for Psychological Science. According to the published abstract of the talk... he will discuss the limits of the mirror mechanism in understanding other people. He will stress that the parieto-frontal mirror mechanism is, however, the only mechanism that allows a person to understand others’ actions from the inside, giving the observing individual a first-person grasp of other individualsâ€........ Read more »

  • April 26, 2011
  • 09:39 PM

Relation between production and perception of voice onset time in aphasia

by Greg Hickok in Talking Brains

I'm constantly amazed at how much good information is available in the literature going back decades. It is unfortunate that much of this information is effectively lost to the current generation of researchers leaving us to re-invent the wheel in many cases. Even papers that we may be familiar with can contain tidbits of information that were overlooked. This is the case with a classic 1970s paper by Sheila Blumstein and colleagues -- including my former PhD advisor, Edgar Zurif, who I ment........ Read more »

Blumstein, S., Cooper, W.E., Zurif, E.B., & Carmazza, A. (1977) The perception and production of Voice-Onset Time in aphasia. Neuropsychologia, 15(3), 371-372. DOI: 10.1016/0028-3932(77)90089-6  

  • April 7, 2011
  • 07:23 PM

The new semantic hub: the posterior middle temporal gyrus

by Greg Hickok in Talking Brains

Most of us agree that conceptual information is represented in a broadly distributed network throughout cortex, but there is disagreement about what the organizational principles of this knowledge might be (see debates between Alfonso Caramazza and Alex Martin or Friedemann Pulvermuller), as well as a debate about the system, or "hub", that binds all of this information together. Here I'm going to focus on the latter question.One hypothesis is that the anterior temporal lobe serves as the brain........ Read more »

  • March 10, 2011
  • 05:54 PM

On the relation between language and music

by Greg Hickok in Talking Brains

Much has been said on the relation between music and language. Most of it arguing for common computational foundations:...syntax in language and music share a common set of processes (instantiated in frontal brain area) - Patel, 2003...some aspects of structural integration in language and music appear to be shared -Fedorenko, et al., 2009All formal differences between language and music are a consequence of differences in their fundamental building blocks (arbitrary pairings of sound and meani........ Read more »

Patel, A. (2003) Language, music, syntax and the brain. Nature Neuroscience, 6(7), 674-681. DOI: 10.1038/nn1082  

  • March 9, 2011
  • 02:51 PM

Action understanding "from the inside"? Or is it just sensory learning?

by Greg Hickok in Talking Brains

As I noted previously, Rizzolatti and colleagues have backed off the claim that mirror neurons enable action understanding via strict motor simulation. Instead they emphasize that the really important mirror neurons code the "goals of the action":By matching individual movements, mirror processing provides a representation of body part movements that might serve various functions (for example, imitation), but is devoid of any specific cognitive importance per se. By contrast, through matching t........ Read more »

  • February 10, 2011
  • 01:13 PM

On the nature of sensorimotor integration for speech processes

by Greg Hickok in Talking Brains

For the last few years I have been thinking a lot about a few different things: What specifically is our proposed dorsal stream doing? How does the motor system contribute to speech perception? What is the relation between sensorimotor processes used during speech production (e.g., feedback-based motor control models) and purported sensorimotor processes in speech perception? How do computational models of speech production (e.g., feedback control models, psycholinguistic models, neurolinguist........ Read more »

  • February 9, 2011
  • 06:15 PM

Why is Broca's aphasia/area the focus of research on "syntactic comprehension"? Was it a historical accident?

by Greg Hickok in Talking Brains

Arguably it was the classic paper by Caramazza and Zurif, published in 1976, that kicked off what turned into decades of research on the role of Broca's area in syntactic computation. We all know from our grade school lessons that Caramazza and Zurif found that Broca's aphasics exhibit not only agrammatic production, but also a profound deficit in using syntactic knowledge in sentence comprehension. The critical bit of evidence was that Broca's aphasics seemed perfectly fine in using semantic ........ Read more »

  • February 2, 2011
  • 05:48 PM

Why is Broca's area active during speech perception?

by Greg Hickok in Talking Brains

A now-common finding in the functional imaging literature on speech perception is that Broca's area is active during the perception of speech. The activation magnitude is sometimes not as strong or consistent as one finds in auditory cortex, but it is there and so requires some explanation. There are a few possibilities. (I'm talking about Broca's area as if it were one functional region, which it isn't, but we'll gloss over that for now.)1. Broca's area drives the analysis of speech sounds (........ Read more »

  • January 26, 2011
  • 09:36 PM

On the relation between auditory-motor area Spt and conduction aphasia

by Greg Hickok in Talking Brains

Conduction aphasia is characterized by relatively frequent phonemic speech errors with self-correction attempts and difficulty repeating speech verbatim; comprehension is relatively well-preserved. The classical account holds that conduction aphasia is caused by damage to the arcuate fasciculus. However, we have been arguing for some time that conduction aphasia is caused by damage to area Spt -- a functionally defined region in the vicinity of the left planum temporale that exhibits auditory-........ Read more »

  • December 1, 2010
  • 03:43 PM

Why the obsession with intelligibility in speech processing studies?

by Greg Hickok in Talking Brains

There was a very interesting speech/language session at SfN this year organized by Jonathan Peelle. Talks included presentations Sophie Scott, Jonas Obleser, Sonia Kotz, Matt Davis and others spanning an impressive range of methods and perspectives on auditory language processing. Good stuff and a fun group of people. It felt kind of like a joint lab meeting with lots of discussion. I want to emphasize one of the issues that came up, namely, the brain's response to intelligible speech and wh........ Read more »

  • October 7, 2010
  • 09:34 PM

Internal forward models -- New insight or just hype?

by Greg Hickok in Talking Brains

In case you haven't noticed, the concept of internal forward models -- an internal prediction about a future event or state -- are all the rage. The concept comes out of the motor control literature where one can find pretty solid evidence that motor control makes use of forward predictions of the sensory consequences of motor commands (e.g., check out the seminal paper by Wolpert, Ghahramani, & Jordan, 1995). These concepts have been extended to speech (e.g., Tourville et al. 2008; van Wassen........ Read more »

Wolpert, D., Ghahramani, Z., & Jordan, M. (1995) An internal model for sensorimotor integration. Science, 269(5232), 1880-1882. DOI: 10.1126/science.7569931  

  • September 29, 2010
  • 02:05 PM

Disconnection between phonological input and output codes

by Greg Hickok in Talking Brains

Neuropsychology is not dead.I just read an interesting case study, in the traditional neuropsych style with a detailed behavioral work up of a single stroke patient and an extended discussion of what the findings mean for models of language processing. I like it. I think we can still learn a lot from this sort of investigation. The paper, by Jacquemot, Dupoux, and Bachoud-Levi (2007), reports on a patient, F.A., who suffered a left temporal-parietal stroke with a language profile typical of co........ Read more »

  • September 21, 2010
  • 06:35 PM

More problems for mirror neurons

by Greg Hickok in Talking Brains

A recent paper in Human Brain Mapping by Molenberghs et al. challenges the view that the motor system is the basis for action understanding and instead implicates, surprise-surprise, a sensory region the superior temporal sulcus. The abstract from this report (see below) provides a nice summary. I know what the response from the MN crowd will be though: the STS must be part of the mirror system! It has been suggested that in humans the mirror neuron system provides a neural substrate for imit........ Read more »

Molenberghs P, Brander C, Mattingley JB, & Cunnington R. (2010) The role of the superior temporal sulcus and the mirror neuron system in imitation. Human brain mapping, 31(9), 1316-26. PMID: 20087840  

  • August 24, 2010
  • 07:42 PM

Neuroimaging of language: Why hasn't a clearer picture emerged?

by Greg Hickok in Talking Brains

This is the question raised in a paper by Evelina Fedorenko and Nancy Kanwisher published last year in Language and Linguistics Compass. The main point that they want to make is that language neuroimagers need to stop doing group studies and start doing functional localization in individual subjects, like the vision folks do. I don't disagree at all; e.g., see this post. In fact, we have used individual subject analyses in several of our papers (e.g., Okada & Hickok, 2006; Okada et al., in pr........ Read more »

  • August 20, 2010
  • 05:16 PM

Conduction aphasia, speech repetition, and the left parietal lobe

by Greg Hickok in Talking Brains

Julius Fridriksson has been featured on this blog before and now his team has just published another noteworthy paper in J. Neuroscience. This paper sought to identify the neural correlate of repetition disorder in aphasia. Repetition deficits are characteristic of conduction aphasia although they are not exclusive to conduction aphasia nor is repetition the only deficit in conduction aphasia. Some historical background is useful, if for no other reason than most people get it wrong in one wa........ Read more »

Fridriksson J, Kjartansson O, Morgan PS, Hjaltason H, Magnusdottir S, Bonilha L, & Rorden C. (2010) Impaired speech repetition and left parietal lobe damage. The Journal of neuroscience : the official journal of the Society for Neuroscience, 30(33), 11057-61. PMID: 20720112  

  • August 11, 2010
  • 02:30 PM

Importance of phonemes in speech production

by Greg Hickok in Talking Brains

In a previous post I have questioned whether we need to explicitly represent phonemes in speech perception. Massaro and others have raised this issue in the past. Phonemes, the line of thinking goes, are only really important for production. There are linguistic arguments for this that I won't detail here. There is also well-known speech error data which shows that phoneme size units can break off and dislocate themselves. Here I want to highlight some evidence from aphasia. A reviewer of ........ Read more »

  • July 30, 2010
  • 11:03 AM

(Mis)understanding mirror neurons -- An alternative interpretation to "action understanding" and why they got it wrong in the first place

by Greg Hickok in Talking Brains

The idea that mirror neurons support action understanding is by far the dominant interpretation of the function of these cells in the monkey motor system. However, it is not the only interpretation. A "sensory-motor" hypothesis, such as that proposed by Cecelia Heyes and others, has been gaining steam in the last few years. In a just published piece in Current Biology, Marc Hauser and I propose a variant of the sensory-motor view, namely that mirror neurons function not for action understandi........ Read more »

Hickok G, & Hauser M. (2010) (Mis)understanding mirror neurons. Current biology : CB, 20(14). PMID: 20656198  

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