All posts filed under “news

Neural effects of tDCS in arithmetic

In our most recent paper, we investigate how brain stimulation (transcranial Direct Current Stimulation, tDCS) can alter neural activity, and how this is specific to a particular arithmetic operation. We used simultaneous tDCS-fMRI to probe the brain regions that are affected by tDCS. We find that activity in the inferior prefrontal cortex is altered during stimulation, but only so when subjects use arithmetic procedures (compared to fact retrieval). These findings are important because they adress two issues: first, it is largely unknown where tDCS really affects the brain – using simulations, we show that these models provide a useful approximation for where the effect really takes place. Second, we illustrate why there is not one single stimulation protocol that enhances all arithmetic/cognitive functions: the brain uses different networks for different functions. So it only works if we stimulate a network that is actually involved. This is also why we need stimulation protocols that are tailored to a specific function, rather than a general “cognition booster”.

Hauser TU, Rütsche B, Wurmitzer K, Brem S, Ruff CC, Grabner RH. (2016). Neurocognitive effects of transcranial Direct Current Stimulation in arithmetic learning and performance: A simultaneous tDCS-fMRI study. Brain Stim

New papers in PNAS

I have been fortunate to coauthor two recent papers, both published in PNAS.
In the first one (Eldar et al., 2016), we investigated how humans develop avoidance habits and how their learning strategies are related to functional activation and gray matter structure in the striatum.
The second publication (Whitaker et al., 2016) is the first paper from our big NSPN study that investigates how the brain and cognitive functions mature over adolescence.

Eldar E, Hauser TU, Dayan P*, Dolan RJ*. (2016). Striatal structure and function predict individual biases in learning to avoid pain. Proc Natl Acad Sci USA 113(17):4812-4817

Whitaker KJ*, Vertes PE*, Romero-Garcia R, Vasa F, Moutoussis M, Prabhu G, Weiskopf N, Callaghan MF, Wagstyl K, Rittman T, Tait R, Ooi C, Suckling J, Inkster B, Fonagy P, Dolan RJ, Jones PE, Goodyer IM, NSPN Consortium, Bullmore ET. (2016). Adolescence is associated with genomically patterned consolidation of the hubs of the human brain connectome. Proc Natl Acad Sci USA

Computational Psychiatry of ADHD

Our new paper in Trends in Neurosciences, we explain how computational psychiatry tries to understand the mechanisms in psychiatric disorders like attention deficit hyperactivity disorder (ADHD). We demonstrate how important it is to have an understanding of several levels of description (Marr’s levels of analysis), and to combine these levels to develop biologically driven, mechanistic new hypotheses about pathomechanisms. In this paper we further suggest that ADHD is mainly a disorder of aberrant neural gain modulation and we show how converging evidence on different levels of description support our notion.

Hauser TU, Fiore V, Moutoussis M & Dolan RJ (2016). Computational Psychiatry of ADHD: Neural Gain Impairments across Marrian Levels of Analysis. Trends Neurosci.

Paper on how to get the timing of fMRI activations – toolbox to come…

Our new paper in the Journal of Neuroscience suggest a new way of analyzing simultaneous EEG-fMRI data. Using this approach, one is able to obtain the timing of multiple fMRI-defined brain regions. We show this in two medial prefrontal areas (vmPFC, dmPFC) in the context of reward learning. In principle, this method is applicable to all simultaneous EEG-fMRI data.
We are thus thinking about implementing the protocol as an SPM toolbox. If you are interested in this, please let us know…
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Slides & Audio Computational Psychiatry course; new paper out

The slides from the UCL computational psychiatry course are now online. There, you can find all slides as well as the audio-files from all the speakers. The talks were all excellent and are worth listening to. My slides, etc, are – of course – also available there. You can find everything here: https://sites.google.com/site/comppsychcourse/2015schedule.

We also just published a new paper on arithmetic learning and tDCS in the European Journal of Neuroscience. More details are available in my post here: http://v1.tobiashauser.ch/papers/arithmetic-learning-modulated-by-tdcs/.

Talk at Computational Psychiatry Course

I will be talking at the UCL Computational Psychiatry Course 29th & 30th April at Queen Square London, together with Karl Friston, Peter Dayan, Michael Moutoussis, Rick Adams, and many other excellent speakers. The course will cover computational modelling, neurotransmitter systems, and also various psychiatric disorders.
I will be speaking about attention deficit/hyperactivity disorder (ADHD) and obsessive-compulsive disorder (OCD).
Have a look at the website of this great course: Computational Psychiatry Website
The organizers also plan to make the talks and slides downloadable on the website for those who cannot attend.

Talks in Munich, Amsterdam; new papers out

I finally managed to (almost) finalize my new website with a more recent and attractive design. I hope you like it – feedback welcome!

Recently, we published two new papers, one by Reto Iannaccone on classifying ADHD, and one by Bruno Rütsche on the impact of tDCS on different arithmetic modalities and their neural correlates. Congratulations to both first authors!

I just returned from the DGKJP conference in Munich, where I presented some new data on OCD – it was great fun. Next week, I was supposed to present data on simultaneous tDCS-fMRI at ICPS in Amsterdam. Unfortunately, I cannot attend the conference. Thus, Roland Grabner will present my slides – he’s an excellent speaker and certainly will do a much better job than I would have…