TESTING MODELS OF SIGNAL INTEGRATION IN MT

1. TESTING MODELS OF SIGNAL INTEGRATION IN MT Valerio Mante, NajibMajaj, Matteo Carandini, J. Anthony Movshon ETH and University of Zurich Howard Hughes Medical Institute and New York University

2. Gratings and plaids

3. Models of MT direction selectivity Component model (Movshon et al. 1983) Abstract Pattern model (Movshon et al. 1983) SH pattern model (Simoncelli and Heeger1998)

4. The stimuli and their velocities

5. Responses of three MT cells

7. Component model

9. Abstract pattern model

11. SH pattern model

12. SH pattern model cells sum the output of the appropriate V1 cells

13. The direction tuning of SH pattern model cells for slow gratings is bimodal

14. Comparison of the models for the 3 cells

15. Comparison of the models for 39 cells

16. Conclusions To fit our data, we extended the original abstract component and pattern models and simplified the SH pattern model. Overall, the SH pattern model and the abstract pattern model performed equally well. But the SH model has fewer free parameters. The SH pattern model predicts some properties that are not explained by the other two.