A Network of excitatory (E) and inhibitory (I) spiking neurons (schematic). Recurrent E connections show short-term plasticity (STP) and complex NMDA dynamics. B Bump-shaped activity profile of the excitatory population, encoding an angle close to 180° in the population vector. Motion of this encoded angle is called drift. C Population vectors storing 6 different angles (red arrows) in working memory (10 repetitions each) at a connectivity of 50%. Without STP the acuity of stored angles is quickly lost due to angular drift (gray lines), whereas STF can stabilize these traces (blue lines).