  We study the structure of generalized parton distributions in impact
parameter space with the aim of determining the size and role of small
transverse separations components in the quarks wave function. We analyze the
relation between transverse momentum components and transverse separations.
Wave functions with large transverse momentum components can simultaneously
reproduce the behavior of the Dirac form factor at large momentum transfer, and
of the deep inelastic structure functions at Bjorken x -> 1. The presence of
large momentum components does not ensure, however, the dominance of small
transverse distances at large x. We suggest that experiments measuring the
attenuation of hadrons in the nuclear medium, or the onset of color
transparency, can provide an alternative source of information on generalized
parton distributions, by mapping out the behavior of the transverse components
of the wave function.
