Guy A Orban, MD, PhD
Lab for Neuro- and psychophysiology
KU Leuven Medical School
Group Leader: Guy A Orban
Senior associate: H Kolster
Post Doc’s: J Jastorff, S Mysore
PhD students: O Joly, R. Abdollahi
Co-Pis: P Janssen, W Vanduffel, M VanHulle, R Vogels
Collaborations: R Peeters (radiology), R Vandenberghe (neurology), G Rizzolatti (Parma)
Science, relevant to NERF
The human brain is the most complicated organ in the biosphere that underpins the diversity of our behavior. Our mental functions are to some degree similar to those of many animals, even of fruit flies. An important question is then to decide how similar mental functions are in animal models as it dictates the choice of the model animals. Some cognitive abilities may be present in primitive form in lower animals, but this does not indicate that the lower animal is a choice model. Indeed rodents and even drosophila can be said to have a function resembling attention, but only non human primates have an attentional function similar to ours. Some functions are uniquely human, even if several species can exhibit a behavior that to some degree resembles that of humans, eg the use of tools. By achieving parallel functional brain imaging in human and non human primates we can illuminate that question in a novel way. Since access to the human brain is restricted, understanding of the neuronal substrate of our mental functions depends on the integration of these indirect human studies with the more direct studies that can be undertaken in model systems. We have achieved this integration by combining parallel imaging in human and non human primates with single cell recording in the non human primate, providing unique insights into complex visual processing such as the extraction of depth structure from various cues present in the retinal image. At present we have reached the point at which we can use functional imaging to define the functional grid in both monkey and human brains: ie to define the cortical areas, which are the building blocks of the visual system. These building blocks can then be targeted for detailed anatomical and functional study.
Potential interactions with NERF
Having defined the blueprint of the human visual system, and that of its best available model, the monkey visual system, one can then target a selected group of areas, known to contribute a behavioral function of interest. The capability to record not single neurons in a given cortical area, but thousands neurons simultaneously in linked cortical areas, will dramatically alter our understanding of cortical functioning. The next step is then to interfere with the neurons in a controlled way to establish causal relationships between neuronal activity and behavior. Finally we will need to unravel the microcircuits that give rise to the functional properties of the neurons under study. Thus our goals are very close to those of NERF and would move them to a model system relevant for the human brain.
Selected publications
- ORBAN G.A., SUNAERT S., TODD J.T., VAN HECKE P. and MARCHAL G. Human cortical regions involved in extracting depth from motion. Neuron, 1999, 24:929-940.
- VANDUFFEL W., FIZE D., MANDEVILLE J.B., NELISSEN K., VAN HECKE P., ROSEN B.R., TOOTELL R.B.H. and ORBAN G.A. Visual motion processing investigated using contrast-agent enhanced fMRI in awake behaving monkeys. Neuron, 2001, 32:565-577.
- VANDUFFEL W., FIZE D., PEUSKENS H., DENYS K., SUNAERT S., TODD J.T. and ORBAN G.A. Extracting 3D from motion: Differences in human and monkey intraparietal cortex. Science, 2002, 298:413-415.
- ORBAN G.A., JANSSEN P. and VOGELS R. Extracting 3D structure from disparity. Trends Neurosci., 2006, 29:466-473
- NEVES H.P., ORBAN G.A. KOUDELKA-HEP M., STIEGLITZ T. and RUTHER P. Development of modular multifunctional probe arrays for cerebral applications. 3rd Int. IEEE EMBS Conf. on Neural engineering. 2007: 104-109.
- JOLY O., VANDUFFEL W. and ORBAN G.A. The ventral premotor cortex processes 3D shape from disparity. Neuroimage, 2009, 47: 262-272
- GEORGIEVA S., PEETERS R., KOLSTER H., TODD J. and ORBAN. G.A. The Processing of Three – Dimensional Shape from Disparity in the human Brain. J. Neurosci, 2009, 29(3): 727-742.
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