Matthew Johnson, PhD, of the Johns Hopkins University School of Medicine in Baltimore, said: "The mind is put into a temporary state of increased flexibility. This is a source of promise and potential risk." This statement refers to the plasticity of the brain. The quote is from an article on MedPage Today titled "That's a source of promise and potential risk": What we heard this week. The article summarizes the key statements from the past week in the field of medicine. Johnson's statement emphasizes the double-edged nature of brain plasticity.