Friday, December 18, 2009

During the holidays, don't forget to submit your papers -- to LCP Cognitive Neuroscience of Language

¿Tired of the same old journals? Nature ... Science ... Neuron ... PLoS ...
¿Tired of Reviewer #3 ruining your holiday vibe (see recent video of reviewer #3's impact ...)?
¿Ready for a new journal to consider your new stuff?

I've announced this before, but I'm not sure people are sufficiently aware: the journal Language and Cognitive Processes now has a regular issues devoted to Cognitive Neuroscience of Language. LCP-CNL is edited by Lolly Tyler and David Poeppel. The first issue was recently published, more papers are in the pipeline.

Please consider sending your work to the journal. We promise to soften reviewer #3's blow. (And analyses appreciating the utility of d-prime will get an extra-fast turnaround. That, after all, was one of the major outcomes of the Neurobiology of Language conference in Chicago.) And at the very least, there now exists another good publication outlet for papers that are theoretically well-motivated, computationally explicit, and neurobiologically sensible.

Don't be shy! Submit early. Submit often.

Tuesday, December 15, 2009

The parallel universes of Broca's area

Update on the function of Broca's area: we still don't know much.

It seems like everyone is studying Broca's area for any number of functions. The most recent is the Science paper that David commented on a while back. That paper argued that Broca's area supports sequential processing of lexical, grammatical, and phonological information. Like other claims about Broca's area, this paper has sparked a debate. For example, see the e-comment by Matt Goldrick et al.

But Broca's area is also a prime suspect in the hunt for mirror neurons, speech perception, syntactic movement, hierarchical structure processing, semantic integration, working memory, and cognitive control. What's interesting (or unfortunate) is that some of these debates go on without reference to others, like they are living in a parallel universe. E.g., you never hear the mirror neuron folks talking about cognitive control and vise versa.

New rule: when speculating about the function of Broca's area you have to at least mention the range of other ideas/data. Maybe this will promote cross-universe interaction.

New rule #2: don't use the term "Broca's area" without further specification. We all know that Broca's area is composed of at least two subregions that seem to do different things. Please specify.

Thursday, December 10, 2009

Postdoc in Barcelona: “Bilingualism and Cognitive Neuroscience” – (BRAINGLOT)

“Bilingualism and Cognitive Neuroscience” – (BRAINGLOT)

1. Position
Post-doctoral position in cognitive neuroscience / multisensory integration
Applications are invited for a full-time post-doctoral research position in the MULTISENSORY
RESEARCH GROUP at the Pompeu Fabra University (Barcelona). The post is part of the BRAINGLOT
project, a Spanish Research Network on Bilingualism and Cognitive Neuroscience (Consolider-Ingenio
2010 Scheme, Spanish Ministry of Science and Education).

2. Project

The project brings together the efforts of several research groups spanning different scientific disciplines
with the common purpose of addressing the phenomenon of bilingualism. The project is conceived with
an open and multidisciplinary vocation, as one of its major anchor points places the stress on the mutual
influence (both in terms of cognitive and neural processes) between bilingualism and other functions such
as auditory perception, multisensory integration, and the executive control attention. This is an excellent
opportunity for professional growth for those interested in the fields of psychology, neurobiology,
cognitive neuroscience or related disciplines including computer science. This position is available mainly
to lead brain imaging studies using fMRI of multisensory integration (possibly complemented with other
methodologies like ERP, behavioral, etc…).

3. Candidate Profile

Candidates must have a PhD and a background in cognitive neuroscience, neuroscience, and/or
cognitive psychology. Previous experience in speech perception and or multisensory processing will be
strongly valued. Experience with functional MRI data analysis and basic programming skills (e.g.,
Presentation, E-prime, and Matlab) is *necessary*. Applicants from outside the EU are welcome to apply
but must qualify for a valid visa.

4. Conditions

• Position: The position will be funded and renewable for up to three years
• Starting date: As soon as possible
• Salary: Commensurate with experience.
• Travel: The project will require short trips within Spain

5. How to apply

Applications should include:
• a C.V. including a list of publications
• the names of two referees who would willing to write letters of recommendation
• a cover letter describing research interests
For informal enquiries about the position and applications, please contact Salvador Soto-Faraco. ( Applications will be accepted until the
position is filled.
Please, mention that you are applying to the POSTDOCTORAL position in the email subject

Wednesday, December 2, 2009

How to make your brain shrink: age

A new study in the Journal of Neuroscience reports that significant reductions in cortical volume occur during normal aging over the span of only one year. The researchers collected MRI data from 142 healthy elderly people aged 60-91 (60 is elderly? Really?). Cortical volume reduction was detectable in several regions, but most prominently in temporal and prefrontal cortices which of course includes regions involved in language function. No wonder I can't remember names anymore...

Fjell, A., Walhovd, K., Fennema-Notestine, C., McEvoy, L., Hagler, D., Holland, D., Brewer, J., & Dale, A. (2009). One-Year Brain Atrophy Evident in Healthy Aging Journal of Neuroscience, 29 (48), 15223-15231 DOI: 10.1523/JNEUROSCI.3252-09.2009

Live videofeed of the sectioning of H.M.'s brain today

Click here to view:

Tuesday, December 1, 2009

Role of the anterior temporal lobe in semantic word retrieval

Lesion studies are making a come back and this is a good thing. fMRI is a good and valuable technique, but it absolutely needs to be balanced with other methods and lesion studies remain important in this respect.

A new lesion study from Myrna Schwartz' group has recently appeared in the advance access section of the journal Brain. The study examines semantic word retrieval in aphasia using a picture naming task. For years this group has been doing fantastic psycholinguistically informed modeling work (with Gary Dell) on naming errors in aphasia and now adds lesion correlation to their arsenal. Using voxel-based lesion symptom mapping (VLSM) in a sample of 64 aphasics, the authors correlated semantic error rate in naming (misnaming elephant as zebra) with the presence or absence of lesion on a voxel-by-voxel basis. They also administered control tasks, one set that sought to identify non-verbal semantic comprehension deficits (Pyramid and Palms & Camel and Catus Tests) and another that sought to identify verbal comprehension (a word-to-picture matching test & a synonym judgment test). The non-verbal control is the most important because it rules out deficits caused by visual analysis of pictured stimuli and general conceptual semantic processes.

Correlation between semantic errors in naming and lesion data identified three main regions, anterior/mid middle temporal gyrus, posterior middle temporal gyrus, and inferior frontal gyrus (BA 45/46) (see figure below).

Factoring out the verbal comprehension measures didn't change the pattern, however, factoring out the non-verbal semantic tests eliminated the frontal and posterior temporal foci, leaving only the anterior temporal regions as significantly correlated with deficits in accessing word- (lemma) level information (see figure below).

A couple of surprising things came out of this study, for me anyway. One is that the anterior temporal focus remained significant even after factoring out performance on non-verbal semantic tests like the Pyramid and Palms Test. Patients with semantic dementia have ATL involvement, do poorly on the PPT, and have been argued to have amodal semantic deficits. I would have predicted that factoring out the PPT would result in only a posterior temporal focus surviving, but the reverse held. This is interesting and useful information.

Another interesting result is that neural systems involved in word-level access in naming (ATL) are not dramatically involved in word-level access in comprehension, otherwise one would have expected the ATL focus to diminish substantially when verbal comprehension is factored out. The non-involvement of ATL regions in comprehension are exactly what I would have predicted based on our claim that posterior regions are critical for this, but I also assumed there was a good deal of overlap in comprehension and production in terms of word-level access. One concern I have is the use of a composite verbal comprehension score that includes both comprehension and a synonym judgment task. If these tasks tap different neural systems to some extent (e.g., temporal vs. frontal respectively) then the composite score may be diluted. I would have liked to see the comprehension score alone factored out.

All in all, this is an important study that will have to be taken seriously by anyone developing models of the functional anatomy of language.

Schwartz, M., Kimberg, D., Walker, G., Faseyitan, O., Brecher, A., Dell, G., & Coslett, H. (2009). Anterior temporal involvement in semantic word retrieval: voxel-based lesion-symptom mapping evidence from aphasia Brain DOI: 10.1093/brain/awp284