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Vision: dynamic processing, plasticity and memory

Research project P4/22 (Research action P4)

Persons :

  • Prof. dr.  ORBAN Guy - Katholieke Universiteit Leuven (KU Leuven)
    Financed belgian partner
    Duration: 1/1/1997-31/12/2001
  • Prof. dr.  FRANCK Georges - Université de Liège (ULiège)
    Financed belgian partner
    Duration: 1/1/1997-31/12/2001

Description :

The visual system is the main sensorial system in primates. It uses the retinal input to build representations of the outside world. These representations reside in the visual cortex, which includes both primary visual or striate cortex and higher order or extrastriate cortex. In non-human primates some 30 visual cortical areas have been identified. The exact number in humans is still unknown, but it should exceed the number present in the monkey. An additional layer of complexity is added by the dynamic nature of visual representations. This dynamic aspect is the specific focus of the IAP. Visual representations are modified in the short term by attention and short-term memory. On a longer time scale they are modified by long-term memory and plasticity in general. These dynamic phenomena are investigated at system level using functional imaging techniques in humans and non-human primates, lesion and single cell recording techniques, as well as at the molecular level.

The coordinating partner at the KUL has gained extensive expertise in visual neuroscience through the use of positron emission tomography (PET), functional magnetic resonance imaging (fMRI), doubly labelled 2-deoxyglucose, single-cell recording, behaviour and lesion studies, chemical neuroanatomy, differential display, and in situ micro-dialysis.

To perform any visual task, the visual system must collaborate with other brain systems. Furthermore, the above-mentioned phenomena all involve interactions between the visual system and other cerebral systems. These interactions are studied collaboratively in the network. The ULg team is known for its work in functional imaging of cognitive functions, notably those involving the frontal lobe. Collaboration between the KUL and ULg will focus mainly on functional imaging of working and implicit memory. The UIA has acquired expertise in analysis of complex systems, notably the cerebellum. Collaboration between the KUL and UIA will centre on analysis of multiple single-cell recordings and on functional imaging of the role of the cerebellum in memory and task dependent visuo-motor associations. A new development resulting from the network's research will be extension of the functional imaging studies to patients. This will lead to better understanding of adult plasticity, a phenomenon underlying recovery after brain lesions.