The influence of dislocations upon carrier mobility and diffusivity is studied through measurements of the electrical conductance of single crystal of olivine during creep deformation in the temperature range 1610-1725 K, under controlled oxygen fugacity and under uniaxial stresses of 60 to 140 MPa. The results presented indicate that under the conditions examined here the generation and movement of dislocations and other defects associated with plastic deformation does not significantly affect the carrier concentration in olivine. One possible explanation of this conclusion may be that dislocation climb in our creep experiments is controlled by the diffusion of electrically neutral defects. In addition, the results indicate that the mobility of the defect responsible for conduction is not significantly perturbed by dislocation effects or that these effects do not exist.