Dynamics of a one-dimensional negative hydrogen ion H- in a strong laser fi
eld is studied. Different approaches (a one-electron model and Hartree and
Hartree-Fock approximations) are compared with the exact numerical solution
of the two-dimensional time-dependent Schrodinger equation. The probabilit
ies of single and double ionization are calculated for various frequencies
and intensities of laser radiation. Strong electron-electron correlations a
re shown to manifest themselves in the ground state and the dynamics of dou
ble ionization in exact two-particle simulations. Stabilization against ion
ization is investigated for a two-electron system. Predictions of a one-ele
ctron model qualitatively agree with the results of exact two-particle simu
lations in the range of intensities corresponding to one-electron ionizatio
n. The approximation of self-consistent field does not seem to be reliable
even in the case of one-electron ionization.