Agnosia

An inability to recognize objects despite adequate sensory information about them reaching the brain via the eyes or ears or through touch. Agnosia is caused by damage to areas of the brain that are involved in interpretative and recall functions. The most common causes of this kind of damage are stroke or head injury. Agnosia is usually associated with just one of the senses of vision, hearing, or touch and is described as visual, auditory, or tactile respectively. Some people, after a stroke that damages the right cerebral hemisphere, seem unaware of any disability in their affected left limbs. This is called anosognosia or sensory inattention. There is no specific treatment for agnosia, but some interpretative ability may return eventually.