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Ad Aertsen

Neurobiology & Biophysics, Faculty of Biology, and Bernstein Center for Computational Neuroscience, Albert-Ludwigs-University, Freiburg, Germany


Wednesday 7 May 2008




Seminar Room B10 (Basement)

Alexandra House, 17 Queen Square, London, WC1N 3AR


Inference of hand movements from population activity in monkey and human sensorimotor cortex:

Towards Brain-Machine Interfaces:


In monkeys, activity of multiple single neurons related to arm movement can be employed to control an external actuator. Based on this work, there is an increasing interest in designing implantable brain-machine interfaces (BMI), enabling real-time control of neuroprosthetic devices. Such movement inference has recently been demonstrated in humans, but little is yet known about the possibility to decode information for the control of reaching and grasping from different sensorimotor areas activated by hand movements. Evidently, specificity and long-term stability of the recorded signals is essential for successful brain-machine interface applications. Thus, a promising novel approach for robust neuro-interfacing is based on neuronal population activity, instead of multiple single neuron activity. Earlier, we demonstrated that local field potentials from monkey primary motor cortex can be as efficient as single neuron activity for decoding arm movements1,2. I will give an overview of these results and present more recent findings3-6, aimed at studying the feasibility of inferring hand movements in humans from single-trial population activity measured with electrodes on the cortical surface or even from the scalp.

Joint work with the Freiburg Brain-Machine Interfacing Initiative (


1. Mehring C, Rickert J, Vaadia E, Cardoso de Oliveira S, Aertsen A, Rotter S (2003) Inference of hand movements from local field potentials in monkey motor cortex. Nature Neurosci 6: 1253-1254

2. Rickert J, Cardoso de Oliveira S, Vaadia E, Aertsen A, Rotter S, Mehring C (2005) Encoding of movement direction in different frequency ranges of motor cortical field potentials. J Neurosci 25: 8815-8824

3. Mehring C, Nawrot MP, Cardoso de Oliveira S, Vaadia E, Schulze-Bonhage A, Aertsen A, Ball T (2004) Comparing information about arm movement direction in single channels of local and epicortical field potentials from monkey and human motor cortex. J Physiol (Paris) 98: 498506

4. Pistohl T, Ball T, Schulze-Bonhage A, Aertsen A, Mehring C (2008) Prediction of arm movement trajectories from ECoG-recordings in humans. J Neurosci Meth 167: 105-114

5. Waldert S, Preissl H, Demandt E, Braun C, Birbaumer N, Aertsen A, Mehring C (2008) Hand movement direction decoded from MEG and EEG. J Neurosci 28: 1000-1008

6. Ball T, Demandt E, Mutschler I, Neitzel E, Mehring C, Vogt K, Aertsen A, Schulze-Bonhage A (2008) Movement related activity in the high gamma range of the human EEG. NeuroImage, in press


This report summarizes results from ongoing collaborations both within and beyond the Freiburg Brain Machine Interfacing Initiative. Contributions by and stimulating discussions with members of the BMII and with the labs of Eilon Vaadia, Alexa Riehle and Niels Birbaumer are gratefully acknowledged. Work supported by German Federal Ministry of Education and Research (BMBF Grant 01GQ0420 to BCCN-Freiburg, BMBF-GoBio, BMBF DIP3.2-Metacomp, BMBF-Bernstein Partners). Further information at and