  Hilbert space structure is assumed as a valid geometric description for
neurodynamics, i.e., for applying any kind of quantum formalism in brain
dynamics. The orientation selectivity of the neurons is used as a justification
to construct a type of statistical distance function which is proportional to
the usual distance (or angle) between orientations of the neurons. The
equivalence between the statistical distance and the Hilbert-space distance is
discussed within this framework. It gives rise to the possibility of
reanalysing the issue of measurement and information processing in the brain
function
