Friday, June 19, 2009


Brain Cognition and Language Lab, Department of Biology, University of Texas at San Antonio

The Brain Cognition and Language lab at the University of Texas at San Antonio is seeking a postdoctoral researcher in the area of cognitive neuroscience of language. The research emphasis will be in understanding adult real time language comprehension. The primary technique used is Event Related Potentials (ERP). The lab also recently acquired a state-of-the-art eye-tracking system. Dr. Nicole Wicha is head of the lab, as well as Chief of the ERP lab at the Research Imaging Center at UT Health Science Center - San Antonio, where a variety of imaging techniques are available, including PET, fMRI and TMS.

Dr. Wicha is an Assistant Professor in Cognitive Neuroscience, and received her PhD in Cognitive Science in 2002 from the University of California at San Diego, under the mentorship of Drs. Marta Kutas and Elizabeth Bates.

Dr. Wicha's lab has several active research lines, many with a bilingual focus, including comprehension of language switches, influences of L1 on L2 comprehension, and the basis of bilingual arithmetic, and more general questions, such as understanding the predictive nature of sentence comprehension, uncovering interactions between different levels of language processing and the intersection between language and other aspects of cognition.

Applicants must have a PhD and a strong background in the cognitive psychology or neuroscience of language, or related fields, as well as statistics and experimental design. Experience with eye tracking, ERP, EEG or other neuroimaging methodologies and analyses is preferable. Proficiency in Spanish, or another language, is beneficial.

This position is available immediately, and will be funded by NICHD SC1 HD060435. Salary is commensurate with NIH guidelines. UTSA is an equal opportunity employer committed to creating a diverse, cooperative work environment. Women, members of under-represented minority groups and individuals with physical disabilities are encouraged to apply.

To apply please send a CV, statement of research interests and 3 letters of references to:
Nicole Y. Y. Wicha, Ph.D.
Department of Biology
University of Texas at San Antonio
One UTSA Circle
San Antonio, Texas 78249-0662
(210) 458-7013

Dispatches from the front of irrational reviewing

Here is a comment taken from a review that a friend just received. Given the reviews I have gotten over the years -- some on papers that Greg and I have written jointly -- I must admit that it takes the edge off a bit to see my friends get hassled this way ... :-) Of course, we all experience this kind of irritation. And it goes without saying that the bad reviews one receives about one's own work are always the most dumbass and irrational.

This stuff, though, is good, a real gem I just saw in a grant review: "they set their goals too high attempting to reveal the "holy grail" of cognitive neuroscience, the brain mechanisms of a particular psychological function."

HUH?? All I can think of is John McEnroe's line, yelled at the tennis umpire: "You can't be serious!! You can't be serious!!!!" My friend, a productive and creative scientist who has done new and cool stuff in cognitive neuroscience, has plenty of street cred. So where a reviewer gets off with this kind of comment is hard to imagine. My mirror neurons and my empathic system are unable to recreate this level of bs.

What was the reviewer hoping for? What is the credible alternative?? Are we looking, instead, for, say, 'just some vague hints concerning some general function'??? What would that even mean? If cognitive neuroscience reviewers think that ambitious and theoretically well-motivated research violates their religious predilections because of the holy-grail-iness of the research aim, they should recuse themselves.

Aren't specific mechanistic hypotheses about specific psychological functions (and their parts) exactly what we should be looking for? I thought we were in the business of identifying the 'parts list' of the mind/brain and figuring out how the parts relate and underlie perception, action, memory etc etc etc ...

And just to round things out ... Here a comment from a referee on a manuscript submission (different genre, different friend) -- equally unusual commentary, though: "The authors' disdain for language as it is used also becomes apparent when they construct their stimuli." Hmmm, really? Wow. Disdain for language, eh? In the stimuli. Right. This reviewer clearly has to stick with decaf ...

Yours from the grail-trail,

Monday, June 8, 2009

UNLV Postdoctoral Position: Perception and Cognitive Neuroscience

Postdoctoral Research: Perception and Cognitive Neuroscience (Postdoctoral Position)
Auditory Cognitive Neuroscience Laboratory, Psychology, University of Nevada, Las Vegas

The Auditory Cognitive Neuroscience Laboratory at the University of Nevada, Las Vegas invites applications for a one-year (renewable up to several years) postdoctoral fellowship to conduct research on the neural basis of auditory and visual perception in healthy individuals and in individuals with schizophrenia. Applicants are expected to have completed a Ph.D. in Psychology, Cognitive Science, or Neuroscience, and have published (or had accepted) research in one or more of these areas, with particular expertise and continuing interest in using psychophysical and/or non-invasive brain measurement techniques to understand mechanisms of perception and cognition. The salary range begins at approximately $36,000 annually, depending on years since Ph.D. according to the NIH post-doctoral scale. The ideal candidate will have experience carrying out research using some combination of psychophysical, ERP, MEG, structural MRI, and functional MRI techniques, using software such as Matlab/EEGLAB, Presentation, and BESA. Interviews will be conducted until the position is filled, and the position may begin as early as the Fall of 2009. Apply online at by submitting a detailed letter of interest, a detailed curriculum vita including a list of references, and relevant scholarly publications. For specific questions regarding the position, contact Dr. Joel Snyder at Information about the laboratory is available at EEO/AA Employer

Contact Information:
Joel Snyder
Department of Psychology
University of Nevada, Las Vegas
4505 Maryland Parkway- Mail Stop 5030
Las Vegas, NV 89154-5030

Tuesday, June 2, 2009

Can fMRI adaptation demonstrate (or refute) the existence of mirror neurons?

A recent fMRI study published by Caramazza and colleagues in PNAS used an adaptation paradigm and found no evidence for the existence of mirror neurons in humans. Basically, in brain regions that are thought to house mirror neurons, executing the same action twice in a row resulted in an attenuation of the fMRI response (the so-called adaptation effect) whereas executing and then observing the same action did not result in adaptation. The latter finding was taken to indicate that cells in these regions are not coding for both action execution and action observation, as one should find if mirror neurons exist.

Marco Iacoboni questioned this logic by arguing with the source of the underlying signal in adaptation studies:

adaptation paradigms ... change synaptic efficacy, which is invariably associated with a decoupling between action potentials and local field potential. When action potentials and local field potential do not correlate, the fMRI signal correlates with the local field potential, not the action potential. This means that Caramazza is not imaging action potentials. And guess what? Mirror neurons are defined by patterns of action potential activity. (see the full commentary here)

Iacoboni cited a paper by Bartels, Logothetis, and Moutoussis (2008) to support his claim. I wouldn't argue with Iacoboni's general argument that because fMRI may not be measuring spiking activity we cannot conclude from the PNAS study that mirror neurons do not exist (way too many negatives in that sentence but you get the idea). I would argue however with his apparent confidence regarding what the source of the fMRI adaptation signal is.

What Bartels et al. argue (convincingly) is that the BOLD response is complex, being driven by some combination of spiking activity and dendro-somatic activity, the later thought to be reflected in local field potentials. These two types of activity can dissociate and it is possible (likely even) that much of the BOLD signal under some circumstances reflects primarily non-spiking activity. In a specific case where detailed single-cell neurophysiology is available, namely direction of motion specificity in area MT, Bartels et al. argue that adaptation effects found in MT for direction selectivity do not reflect adaptation in spiking activity in MT but rather are a downstream reflection of such adaptation which happens elsewhere. The more general point they make is this:

the presence or absence of adaptation in an area measured using fMRI therefore does not allow for the conclusive inference of either the presence or absence of the neural property in question

So from the Caramazza study we cannot conclude whether cells in their ROIs exhibited adaptation or not in their spiking patterns because the adaption that was observed (e.g., for executing an action twice, the E-E condition) might be nothing more than a downstream reflection (inputs from) the site of the actual adaptation.

Let's run with this possibility. Suppose some upstream area outside the presumed human "mirror system" is actually where the E-E adaptation effect is occurring (note that the human mirror system has been identified using fMRI with its uncertain signal source). In this unidentified area that is sensitive to action execution we might expect to find not only adaptation for E-E events but, if mirror neurons exist, also for E-O (execute-observe) events. Yet no such adaptation was found.

Put differently, Bartels et al. arguments apply to making inferences about the cell properties within the adapting region identified with fMRI, not about making inferences regarding the existence of a cell population somewhere that shows adaptation.

For this reason, I think it is a serious mistake to dub Caramazza and colleagues study as fatally flawed and disregard it completely. It failed to identify any evidence of neural adaptation between action perception and action execution within the human "mirror system". Assuming a "downstream" argument for adaptation effects, what this might mean is that the human "mirror system" is treating action observation and action execution as distinct types of events either because there are no cells in this system that respond to both or because inputs to these regions treated these events as distinct.

At the same time, I think it would be a serious mistake to take this study as conclusive evidence that mirror neurons do not exist in humans. In fact, given our limited understanding of the source of the fMRI signal, I have a hard time taking any single fMRI study as conclusive evidence for anything. One needs converging results from multiple methods to make any kind of strong conclusions.


BARTELS, A., LOGOTHETIS, N., & MOUTOUSSIS, K. (2008). fMRI and its interpretations: an illustration on directional selectivity in area V5/MT Trends in Neurosciences, 31 (9), 444-453 DOI: 10.1016/j.tins.2008.06.004