Figure 6.

Predictions of the model for a nondirectional adaptor and experimental validation. Circles indicate measured biases after adaptation to the vertically drifting adaptor. The model predicts that this adaptor only engages the nondirectional mechanism. Bold lines represent the model prediction for the three subjects based on their individually estimated model parameters from the primary adaptation condition. The measured biases confirm the model prediction. In particular, they are all anti-symmetric about zero motion, as expected for the signature of a nondirectional mechanism. For subject 2, the prediction slightly underestimates the effect at high speeds.