1. The functional connectivity of cortical areas Or how to produce many numbers

2. Coordination of different modules

3. Structural equation modelling Popular in behavioral sciences - e.g. „whats role of intelligence in performance?“ Identify latent factors in data - structure in covariance matrix - confirmatory vs exploratory Roots in path analysis (Wright, 1921) General model: DATA = MODEL + ERROR - reduce error http://www.gsu.edu/~mkteer/semfaq.html

4. Graphical representation Measure 1 Measure 2 Measure 3 Factor 1 Factor 2 Causal Correlates Error 1

5. Formal representation Measurement = weighted latent factors + error

6. Aplication to fMRI data Effective connectivity vs functional connectivity Ec: influence of one neuronal system on another Fc: temporal correlation of two neurophysiological events Anatomy can inform choice of factor loadings

7. How to estimate effects over time? Simple regression model: Y = xB + u Include time: Y t = x t B t + u t Estimate evolution B using Kalman filter - predictor-corrector algorithm

8. The paradigm I. Toni, J. Rowe, K.E. Stephan & R.E.Passingham. (2002). Changes of cortico-striatal effective connectivity during visuomotor learning. Cerebral Cortex 12:1040-1047

9. What are the modules?

10. The model

11. The result

12. What have we learned? Your turn!

13. An application to fMRI