Mild cognitive impairment is a condition which is often a precursor to Alzheimer's Disease, but not everyone will go on to develop the condition. If researchers could discover who does develop the disease and who doesn't it would have implications for therapy. Claudia talks to researchers about some of the latest research in this area and discovers how the loss of brain cells in a region of the brain known as the hippocampus leads to the characteristic symptoms of the disease.

At the scene of a disaster it is now common for counselling to be provided for the victims, but will everyone develop post traumatic stress disorder PTSD? John Marzillier, a researcher in this area with 40 years experience, says everyone responds differently and only 10% of people are likely to develop PTSD.

Why do we continue to believe information even when we are told it's wrong? Claudia Hammond discovers how the brain stores facts and why we don't erase erroneous explanations.