In the 1960s, Russian neuropsychologist Alexander Luria began studying the behavior of individuals with frontal lobe injuries, who while functioning normally in many ways, also demonstrated profound social, emotional, or cognitive dysfunctions. For example, a patient asked to raise his arm off a table might be able to do so but become confused if his arm was covered with a sheet because he was not specifically told to remove the sheet before raising his arm. Similarly, a patient’s attention to a task might be easily interrupted by the sound of an object dropped on the floor.