Apraxia is a motor disorder caused by damage to the brain (specifically the Anterior parietal cortex), in which someone has difficulty with the motor planning to perform tasks or movements when asked, provided that the request or command is understood and he/she is willing to perform the task. A person with apraxia cannot move his or her lips or tongue to the right place to say sounds correctly because, even though the muscles are not weak, the message from the brain to the mouth are disrupted. The nature of the brain damage determines the severity. Apraxia is an acquired disorder of motor planning, but is not caused by incoordination, sensory loss, or failure to comprehend simple commands (which can be tested by asking the person to recognize the correct movement from a series). It is caused by damage to specific areas of the cerebrum. Apraxia should not be confused with ataxia, a lack of coordination of movements; aphasia, an inability to produce and/or comprehend language; abulia, the lack of desire to carry out an action; or allochiria, in which patients perceive stimuli to one side of the body as occurring on the other. Developmental coordination disorder is the developmental disorder of motor planning.