The goal of this experiment is to better understand the molecular dynamics in polystyrene in order to shed light on the discrepancy between beta-NMR and low-energy muSR experiments on the depth dependence of enhanced dynamics near a free surface. We propose to measure the temperature dependence of the muon relaxation in a weak transverse field (1/T2), which we believe will be more sensitive to probing the molecular dynamics than measurement of the muon relaxation in longitudinal field. The temperature dependence of 1/T2 will allow us to determine the parameters for torsional motion of the phenyl rings and will be compared with the results of beta-NMR and neutron scattering experiments. The results of the proposed experiment will allow us to submit a proposal to PSI to remeasure the depth dependence of enhanced dynamics in polystyrene on LEM and resolve the controversy.