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Discussion and Conclusion

First, we want to emphasis that in all the comparisons, the same tuning width is used and the strength of decorrelation feedback is the only fit parameter. It does not take much imagination to see that the quantitative agreements between the theory and the experiments are good. Further more, we derived the relationships for the maximum effects, which are independent of the parameter and have been partially confirmed by the experiments.

The decorrelation feedback parameter is not necessarily the same for the two effects. Indeed, it could be quite different for different human subjects and different experimental setups. But the orientation tuning width should be the same for the two effects and roughly the same for different human subjects.

Recent neurophysiological experiments revealed that the surrounding lines did influence the orientation selectivity of cells in primary visual cortex of the cat [13]. Those single cell experiments land further support to our theory. But one should be cautioned that the cells in our theory should be considered as the average over a large population of cells in cortex.

Finally, this is not merely a theory for the development and the adaptation of orientation selective cells, it can account for effect such as human vision adaptation to colors as well (see Appendix). Actually, we believe that the associative decorrelation dynamics captures a general principle of information processing of neural systems and that future experiments could give us more quantitative results to further test our theory and help our understanding of neural systems in general.



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Next: Appendix Up: Associative Decorrelation Dynamics in Previous: Second Order Effect