Extension of Superior Colliculus Based Models of Multisensory Integration to the Cortex

1. Extension of Superior Colliculus Based Models of Multisensory Integration to the Cortex Michael Hadley

2. Multisensory Integration • Windows of interaction • Convert physical properties to neural firings • Integrate to create a more accurate representation

3. Sensory Structures • Information is information • Similar hierarchy • Plasticity rules • Topographical maps • SOM

4. Multisensory Integration in the Cortex Traditional View New Evidence

5. Major Discoveries • Connections between sensory areas • ERP time frames of integration • Earliest window defies traditional view • Later windows fit traditional view • Convergence • Single/multi-cell recordings • Population recordings

6. Traditional vsRecent

7. Computational Modeling • Test hypotheses • Generation of testable predictions

8. My Proposal • Move subcortical model to cortex • Change the model to fit cortical data • Start to put the puzzle together

9. Definition

10. Anastasio & Patton’s Model of the SC Modulatory projections come from parietal regions V = visual A = auditory S = somatosensory DSC stands for the deep layer of the SC Primary inputs come from sensory receptors

11. A&P Two Stage Training • Hebb • Primary connections • Uses SOM • Extracts information • Hebb-anti-Hebb • Modulatory connections • Loosely based on opposite of Hebb • Training to produce MSE

12. Fit with Literature • Ascending/descending from literature • Modulatory role of descending • Developmental window • Does not show MSD • No inhibition

13. My Model

14. Stage 1 Training of the forward sensory projections with SOM Training of the projections to association areas with SOM

15. Stage 2 Hebb-anti-Hebb training according to traditional theories Hebb-anti-Hebb training according to new evidence

16. Evaluation • Use definition of multisensory integration • Determine which theories are plausible • Information theory • Incorporate inhibition • Supervised learning Future