After a stroke affecting the right side of the brain, many patients are affected by "spatial neglect": the damage to the brain causes them to ignore the left side of their surroundings. At its most extreme they may be unaware that they have a left side, or believe that it is moving normally when it is in fact paralysed. In milder cases, people may be unable to recognise touch on the left side if their right side is also being touched, or objects in their left visual field if something is visible to their right. Neglect alters peoples' quality of life profoundly, often renders them more dependent on others to undertake basic activities of daily living, and makes effective rehabilitation much more difficult.