We use the stochastic Schrodinger equation approach to examine an experiment performed by Scherer, Jonas, and Fleming [J. Chem. Phys. 99, 153 (1993)]. They have excited I-2 molecules dissolved in n-hexane with a strong, ultrashort pump pulse. This creates moving wave packets on both the excited and the ground electronic states. The coherent motion of these packets is studied by measuring the absorption of a weak probe pulse, as a function of the delay time between the pulses. We show how the oscillations in the signal are connected to different excitation mechanisms and to the interference between various packets created by the lasers. Our purpose is to clarify the dynamics of the packets and to show that the stochastic Schrodinger equation approach can be used to study their decoherence. We did not intend to try to develop a realistic model for the I-2 dynamics and its interaction with the solvent and do not perform a detailed comparison with the experiment. Nevertheless, the calculations reproduce, semiquantitatively, the observations.