Affiliations: Address for correspondence: University of Zurich,
Institute of Psychology, Zürich, Switzerland
Note: [] Address for correspondence: Valentine L. Marcar, University of
Zurich, Institute of Psychology, Binzmühlestrasse 14, CH-8050 Zürich,
Switzerland
Abstract: Purpose: This paper will examine different neurocognitive theories
which conclude that the brain is able to restore or redress lost or damaged
processing systems by reorganising remaining neuronal resources. Method: The blood oxygenation level dependent or BOLD-signal is the most frequently
used method for imaging brain activity in healthy, young adults, children, the
elderly, or subjects with a neurodegenerative condition. The BOLD-signal
reflects the balance between oxygen metabolism and vascular blood supply. The
effect of neuronal discharge activity and neuronal recruitment on oxygen
metabolism and vascular blood supply will be described. Result: Maturation, senescence or degenerative illness alter the balance of oxygen
metabolism and vascular blood supply on a regional level. This changes the
ability to detect brain activity using the BOLD-signal and accounts for the
activation pattern observed in the young, the old and the ill. Conclusions: The change in activation pattern observed in the young, the old
and the ill is not the result of a compensatory mechanism but the result of a
disparity in the neuronal process which can not be compensated for.
