Figure 9.

Drift and long-term stability in the circular arena. Tuning curves are processed in the same manner as for previous figures, but now separated by 1 min epochs. The shading of the tuning curves becomes brighter from minute 1 to minute 20; that is, the darkest curve is the earliest estimate (minute 1). A, With hardcoded Vis-to-RSC connections (average learned weights of previous simulations, bottom right panel, average weight matrix), tuning curves are stable from the beginning. The average weight matrix illustrates the band-like structure of the learned weights, each band corresponding to weights from Vis (pre) to 1 particular RSC sheet (post). B, In the learning setup (initially zero connection weights), weak drift is present (here 0.028°/s, averaged over all quadrants). Results for the rectangular arena are qualitatively similar.