Here's a screen cast about the Hopfield network emulator which uses ECAN:
http://fruitionnz.com/dist/OpenCog-HopfieldNetwork.avi (~60M)
If you have any questions or want to know further details there is an
ECAN IRC session is April 15 4-6pm EDT, 8-10pm UTC/GMT
http://opencog.org/wiki/OpenCogPrime:TutorialSessions2009
Cheers,
Joel