Figure 11.

Predictions of A, the bump attractor model suggesting that drift is the main source of imprecision in working memory vs. B, a model where the bump of activity decays. C. For the bump attractor, but not the decaying bump model, the tuning curve bias computed from trials with clockwise versus counterclockwise deviations becomes increasingly positive through the delay. D. Only for the bump attractor model, spike counts in response to flank stimuli correlated with behavioral deviations in the direction of the neuron’s preferred cue as delay progressed. E. For the bump attractor model, but not the decaying bump model, Fano Factors computed separately for trials when a flank stimulus was presented are larger when considering inaccurate trials with large behavioral deviations (solid line) as compared to accurate trials (dashed line). F. Only for the bump attractor model, neuron pair noise correlation is negative for those pairs with dissimilar tuning, when responding to a middle flank stimulus. From Wimmer et al., 2014.