I randomly stumbled across these when channel hopping at 4am a month or two ago and was captivated. It's a great series and the format of having a panel of experts discussing a subject with only casual prompts from Rose is great (a format that works well with the BBC's In Our Time podcast too).
Are these episodes available online somewhere? Does PBS put them up?
You can watch them on the site linked with this post. It's not entirely obvious but you click on the main frame when you go to a specific episode and it brings up a Flash video player.
If you enjoy this series you will love In Search of Memory by Eric Kandel the co-host of this series.