General information

Research at the Laboratorium voor Neuro- en Psychofysiologie.

A joint research group at the K.U.Leuven Medical School.
Principal Investigators:
Prof. P. Janssen, Prof. G.A. Orban, Prof. W. Vanduffel, Prof. M. Van Hulle, Prof. R. Vogels.

Our research group investigates neural processes in the visual cortex, in particular the extrastriate or higher order cortex, of human and non-human primates.

The main tools are single-cell recordings, multiple cell recordings, human and awake monkey fMRI, modeling and computational studies, lesion and inactivation studies, behavioural studies and psychophysics.

Particular topics of present interest are motion and action processing, 2D shape and 3D shape processing, using multiple sources of information, material properties. In addition to these topics studied chiefly in passive subjects, the group also investigates neural substrates of visual attention, working memory, recognition and categorization, numerical processing. Finally at the technical level, the group investigates the relationship between neural activity and fMRI signals, homologies between human and non-human primates, as well as novel imaging brain tools.

The group is supported by GOA, IAP, EF, GSKE, FWOV, HFSP and EU (FP6).

Research interests of principal investigators:

Prof. Peter Janssen MD, PhD

• Coding of 2D and 3D shape in posterior parietal cortex.
• Functional interactions between posterior parietal and inferior temporal cortex during 3D shape discrimination and grasping.
• Spatial attention.
• Timing mechanisms in posterior parietal cortex during eye movement tasks.
• Development of multielectrode arrays for chronic recordings.

Prof. Guy A. Orban MD, PhD

• Processing of lower order and higher motion, of kinetic boundaries, 3D structure from motion, from stereo, from shading and from texture, combination of cues. Processing of material properties, processing of actions and intentions.
• Neural substrates of visual attention, visual search, discrimination learning, working memory, numerical processing and prospective memory.
• Adaptation as a tool in fMRI, asymmetries in visual field, relationship single cells and fMRI, homologies between human and monkey, DTI, functional connectivity in fMRI; Pharmacological interactions with activation in fMRI.

Prof. Wim Vanduffel, PhD
Currently ongoing awake monkey (f)MRI-projects include:

• three-dimensional structure from motion.
• two-dimensional structure from motion.
• cue-convergence.
• retinotopy.
• figure-ground segmentation.
• interactions between brain regions using reversible inactivation techniques and microstimulation.
• non-invasive anatomical tract-tracing.
• spatial attention.

Prof. Marc M. Van Hulle, PhD
(Computational Neuroscience Group)

• Development of new algorithms, non-parametric statistical techniques and software tools for analysing fMRI data (localization) and for modeling functional cortical networks from fMRI data.
• Development of new algorithms for spike detection and spike sorting of multi-electrode recordings, for connectivity analysis and decoding.
• Development of new non-linear signal processing techniques for characterizing the stationarity, linear and stochastic nature of time series, including fMRI signals (BOLD and MION).
• Development of new object segmentation algorithms based on heading and binocular disparity, and cue fusion.
• Development of new algorithms for multi-scale optic flow and binocular disparity computation.

Prof. Rufin Vogels, PhD

• Coding of shape and other object attributes in the ventral visual stream, mainly using single cell recording in awake, behaving rhesus monkeys.
• Coding of 3D shape, defined by stereo, texture and/or shading cues. Coding of 3D texture - materials.
• Plasticity of visual representations. Task-dependent modulation of visual responses. Visual categorization.
• Relationship between single cell selectivity and fMRI activation.

Integration in research networks:

• Leuven Cerebral Cortex Center (LC³) (Excellentie Financiering, coordinator)
• National IAP VI/29 (coordinator)
• European:
  
  

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  Neurocom (coordinator) DRIVSCO (partner) MCCOOP (partner)