  The spin structure of the nucleon is studied in a light-cone description of
the nucleon where the Fock expansion is truncated to consider only valence
quarks. Transverse momentum dependent parton distributions and transverse-spin
densities, defined through the generalized parton distributions in the
impact-parameter space, are investigated as new tools to reveal the spin-spin
and spin-orbit correlations for different quark and nucleon polarizations.
