October 12, 2009
- No lab meeting next week (10/19)
- Check on flights to Banff 11/8-15 (Sunday to Sunday)
- Skiing?
- Look at chapter for Stacey/Lena about PCA/NMF
- SfN meeting - posters on Saturday, motor meeting on Friday.
Lucas' Presentation
- Does the nervous system reduce the dimension of sensory information?
- Use cats to test this question
- 2D stimulus
- Sensory input dimension is assumed large due to many joints perturbed
- We can separate sensory response, emg response and mechanical response due to the delays in the system
- Joint angles are projected to sagittal and transverse plane
- Doing PCA on the covariance was bad because...this emphasizes fitting data to noise
- Doing PCA on the correlation was good because...only used variables that reconstruct non-noisy values
- Results
- Platform perturbation results in a higher dimensional perturbation
- Dimension is higher in disturbance than in response