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Mechanisms of top-down control in the accumulation of sensory evidence

Summary

Perception is affected by top-down factors such as attention and expectation. Many studies have shown neurophysiological correlates of these top-down factors, which are already active prior to the sampling of sensory evidence. Importantly, in anticipation of an upcoming target, oscillatory amplitude in the alpha- and the beta-band decreases in the relevant (i.e., attended) sensory cortex. One of the puzzling aspects of this line of investigation is the rather weak relation between pre-target alpha/beta oscillatory amplitude and perception (most importantly, accuracy). The overall objective of this project is to identify additional neurophysiological processes that explain behavioral accuracy and its modulation by attention. We put forward two working hypotheses that guide us in this search: (1) it is essential to not only investigate anticipatory neural activity but also the neural activity during accumulation of sensory evidence, and (2) the behavioral relevance of selective attention is in part due to its ability to suppress distracting sensory input. The main objectives of this project are threefold: (1) extracting the neural signature of processes that predict behavioral accuracy in perceptual identification, (2) specifying how spatial and feature-based attention modulate these processes and to what extent this explains the attention-induced improvement in behavioral accuracy, and (3) specifying how the presence of distractors modulates these neural processes as well as their behavioral relevance. These objectives will be addressed in experiments in which extracranial neural signals will be recorded using Magnetoencephalography (MEG).

Work environment

The Donders Institute for Brain, Cognition and Behaviour is a leading research institute with a strong international reputation. We are a relatively new institute with an enterprising spirit and an excellent track record. Our scientific output is prolific and renowned for its quality. Over 500 researchers work here on unravelling the mechanisms of the brain. Our research focuses on cognition and behaviour in relation to its neuronal substrate, including neurophysiological, genetic, and molecular processes.

Within the Donders Institute (DI), you will work at the Donders Centre for Cognition (DCC), which is one of the three research centres of the DI. However, as this is a collaborative project, you will also be affiliated with the Donders Center for Cognitive Neuroimaging (DCCN), which is another center of the DI. At the DCC, you will belong to the research group Neurophysiology of Active Perception (PI Eric Maris) and at the DCCN you will be affiliated to the research groups Prediction & Attention (PI Floris de Lange) and Neuronal Oscillations (PI Ole Jensen).

Job Requirements

A successful candidate has a Master's degree in a field at the interface of behavior and neurobiology (Cognitive Neuroscience, Neurobiology, Cognitive Science) and excellent analytic and quantitative skills. Programming skills (e.g., Matlab) are required, and it is an advantage if you have experience in running EEG or MEG experiments.

Conditions of Employment

We offer you:
- employment: 1,0 fte;
- in addition to the salary: an 8% holiday allowance and an 8.3% end-of-year bonus;
-  the gross starting salary amounts to €2,042 per month based on full-time employment, and will increase to €2,612 per month in the fourth year, based on a 38-hour working week;
- you will be appointed as a PhD student (1 FTE) for a total of 4 years. Your performance will be evaluated after 18 months. If the evaluation is positive, the contract will be extended by 2.5 years;
- it is in principle possible to participate in educational activities;
- you will be classified as a PhD student (promovendus) in the Dutch university job-ranking system (UFO).

Further Information

dr. Eric Maris
E-mail: e.maris@donders.ru.nl 
www.nphyscog.com

Applications

Please include with your application:
- a curriculum vitae, including academic qualifications, grades, a list of publications (if applicable), and the names and contact details of two referees;
- a letter explaining your motivation, your interest in the project, and your competence in the research field;
Please send your application e.maris@donders.ru.nl.