As the ten year anniversary of the 2005 London bombings approaches, Claudia Hammond talks to Rachel Handley, a clinical psychologist whose first job was to treat people for Post Traumatic Stress Disorder and travel phobia after the bombings. She talks about the overwhelming guilt felt by many people she counselled and how cognitive behavioural therapy helped stop people experience terrifying flashbacks. She explains why PTSD can also have a delayed onset, even as much as ten years after the original event. Also in the programme, Gary Klein discusses his research into insights and whether it's impossible to improve our own capacity to have them. Claudia is joined by cognitive neuropsychologist, Catherine Loveday to talk about new research into emotions and the brain.