1. The inability to recognize certain sensory stimuli: Because of an extensive neural damage as the result of the car accident, Paul's friend experienced aural agnosia.
2. Loss of the ability to recognize people or objects and their meanings: A tragic consequence of the industrial accident was the onset of agnosia making it impossible for some of the workers to continue working because they couldn't remember how to perform their jobs anymore.
3. In medicine, losses of comprehensions at the levels of central nervous systems of any of the senses: The sensory spheres of the agnosias may be intact, but Linda is unable to assimilate the meanings of whatever the senses indicate.

One or several impairments in visual recognition without any apparent damage of intelligence, motivation, or attention when vision is usually intact and the mind is clear: Individuals who are diagnosed with primary visual agnosia find that objects may be identified by touch, sound, or smell. They may not be able to identify a set of house keys by sight; however, it is possible for the person to recognize the keys when they are held in his or her hands.