Imagine this - removing a bad memory or reactivating a good memory may be done at flick of the finger or the click of a mouse. In promising results researchers have erased and reactivated memories in genetically-engineered rats - profoundly altering the animals' reaction to past events. 'We can form a memory erase that memory and we can reactivate it at will by applying a stimulus that selectively strengthens or weakens synaptic connections' explained Roberto Malinow a professor of neurosciences at University of California San Diego's school of medicine. In lab settings scientists optically stimulated a group of nerves in
