Speech perception
Agnosia is "the loss or diminution of the ability to recognize familiar objects or stimuli usually as a result of brain damage". There are several different kinds of agnosia that affect every one of our senses, but the two most common related to speech are speech agnosia and phonagnosia.
Visual agnosia
The two main categories of visual agnosia are:Patient C.K. was born in 1961 in England and emigrated to Canada in 1980. In January of 1988, C.K. sustained a head injury from a motor vehicle accident while out for a jog. Following the accident, C.K. experienced many cognitive issues, mood swings, poor memory, and temper outbursts. C.K. also had motor weakness on the left side and a left homonymous hemianopia. He recovered well, retaining normal intelligence and normal visual acuity. He was able to complete a Masters in History, later working as a manager at a large corporation. Although his recovery was successful in other areas of cognition, C.K. still struggles to make sense of the visual world.