Friday, July 13, 2012


We are looking for a new colleague!  It would be great to have a language person -- we are growing in this area! -greg
Subject to budgetary authorization, the Department of Cognitive Sciences ( at the University of California, Irvine (UCI) has available a tenure-track position at the Assistant Professor level in cognitive neuroscience.
Of particular interest are cognitive neuroscientists who combine experimental research with theoretical modeling or innovative analysis methods.  The successful candidate will interact with a dynamic and growing community in cognitive, computational, and neural sciences within the Department and in the Center for Cognitive Neuroscience.
Irvine is located in Orange County on the Southern California coastline between Los Angeles and San Diego.
The online application includes:
  • A cover letter indicating primary research interests,
  • CV,
  • 3 recent publications, and
  • 3-5 letters of recommendation.
Review of applications will commence on 11/01/2012.
Inquiries about the application process or position should be sent

Thursday, July 5, 2012

What does motor cortex contribute to speech perception? Is it just response bias?

I've been worrying about bias in speech perception experiments for months, particularly those that purport to show that the motor system is involved in speech perception.  The concern is this: virtually all of these studies used measures, such as percent correct or reaction times in forced choice paradigms, that are potentially biased.  Modulations in performance as a function of whatever manipulations are used could result from modulations in perception (what most people are interested in documenting) or modulations in response selection.  A typical experiment is this: subjects listen to pairs of CV syllables and decide whether they are the same or not.  In one condition, they receive TMS to one or another motor area and in the other they get sham stimulation or some other control.  A typical result: percent correct significantly decreases or RTs significant increase with motor stimulation.  Typical conclusion: the motor system is causally involved in speech perception.

Problem: you don't know whether the effect is happening in the perceptual analysis of the CVs or whether it is modulating the decision process.

This worry led to the following experiment, spearheaded by Jon Venezia in my lab.  Using fMRI we modulated response bias while keeping perceptual discrimination constant in a CV same-different discrimination task.  Response bias was manipulated by changing the ratio of same to different trials.  The stimuli were otherwise identical.  We then looked for the neural correlates of response bias changes.

Behavioral results confirmed the intended effect: response bias (measured using the c, or criterion, statistic) was significantly modulated as a function of the ratio of same to different trials (p < .001) whereas d' (perceptual discrimination) was unaffected (p = .384).  The figure below shows the clear effect on bias (top panel) and the somewhat wobbly effect on proportion correct (p = .061).

So what brain regions correlate with the modulation of response bias?  Our favorite motor speech areas (among other non-auditory areas):

Turns out these regions line up quite well with those regions that, when stimulated with TMS, yield effects on "speech perception".

This is not conclusive evidence that all previous effects of motor modulation on speech perception are a result of response bias alone, but it does seriously question the validity of these reports and makes a strong case for the view that we need to take bias into account when measuring "speech perception."

Monday, July 2, 2012

Donders Institute - Senior Researcher position: Intention and Action Group

Donders Institute, Centre for Cognitive Neuroimaging
Vacancy number: 30.05.12
Closing date: 1 September 2012

The Intention & Action group at the Donders Institute for Brain, Cognition and Behaviour has funding available for a senior researcher position. We are looking for a candidate interested in understanding how abstract knowledge gains access to the motor system. This issue will be addressed by studying both healthy and pathological human subjects, using various state-of-the-art neurophysiological techniques available at the Donders Institute (fMRI, MEG, TMS-EEG, tDCS). You are expected to contribute to the development of models of action selection that focus on how percepts and concepts influence a motor plan. We are primarily interested in two types of actions, namely actions that change the physical state of the world according to a desired outcome (instrumental actions), and actions designed to change the mental state of other agents (communicative actions). You are expected to be predominantly involved in empirical research, and to develop an independent research profile, leading to autonomous publications and research grants. You will also be involved in scientific management and academic teaching. The management tasks involve active participation in the daily support of the Intention & Action research group, with a particular focus on supervision of MSc and PhD students. The teaching tasks involve organizing lectures and course material for students of the Donders Graduate School for Cognitive Neuroscience.

Work environment
The Donders Institute for Brain, Cognition and Behaviour consists of the Centre for Cognition, the Centre for Cognitive Neuroimaging and the Centre for Neuroscience. The mission of the Centre for Cognitive Neuroimaging is to conduct cutting-edge fundamental research in cognitive neuroscience. Much of the rapid progress in this field is being driven by the development of complex neuroimaging techniques for measuring activity in the human working brain - an area in which the Centre plays a leading role. The research themes cover central cognitive functions such as perception, action, control, decision making, attention, memory, language, learning and plasticity. The internationally renowned centre currently hosts more than 100 PhD students and post-docs from more than 20 different countries, offering a stimulating and multidisciplinary research environment. The centre is equipped with four MRI scanners (7T, 3T, 1.5T), a 275-channel MEG system, an EEG-TMS laboratory, several (MR-compatible) EEG systems, and high-performance computational facilities. English is the lingua franca at the centre. You will work within the Intention & Action group at the centre.

What we expect from you
As a candidate for the position you should have a PhD degree and scientific experience as a postdoctoral researcher in a field related to cognitive neuroscience. Selection criteria will consider the research impact of the candidate, familiarity with neuroimaging techniques (fMRI, EEG, MEG, TMS), and supervision experience. Proficiency in Matlab, and in oral and written English, is required. You will work in a team, sharing technical know-how and ideas.

What we have to offer
- employment: 1,0 fte; (see also employment conditions)
- in addition to the salary: an 8% holiday allowance and an 8.3% end-of-year bonus;
- depending on experience the gross salary will be between € 3,195 and € 4,970;
- salary scale 11 will apply during the first year;
- duration of the contract: maximum 6 years;
- you will be classified as a Researcher (onderzoeker) level 2 in the Dutch university job-ranking system (UFO).

Would you like to know more?
Further information on the Donders Institute for Brain, Cognition and Behaviour
Further information on the Intention & Action group;
Further information on Ivan Toni (CV; e-mail)

Are you interested? Please submit an application letter defining your research interests, a CV, and the names of two persons who can provide references. It is Radboud University Nijmegen's policy to only accept applications by e-mail. Please send your application, stating vacancy number 30.05.12, to, for the attention of Prof. Dr. Ivan Toni, before 1st September 2012. For more information on the application procedure: +31 24 3611173.