<unk>  is the ability to differentiate information through the sense of touch. The somatosensory system is the nervous system pathway that is responsible for this essential survival ability used in adaptation. There are various types of<unk> . One of the most well known and most researched is two-point<unk> , the ability to differentiate between two different tactile stimuli which are relatively close together. Other types of<unk>  like graphesthesia and spatial<unk>  also exist but are not as extensively researched.<unk>  is something that can be stronger or weaker in different people and two major conditions, chronic pain and blindness, can affect it greatly. Blindness increases<unk>  abilities which is extremely helpful for tasks like reading braille. In contrast, chronic pain conditions, like arthritis, decrease a person's<unk> . One other major application of<unk>  is in new prosthetics and robotics which attempt to mimic the abilities of the human hand. In this case tactile sensors function similarly to mechanoreceptors in a human hand to differentiate tactile stimuli.
Tactile discrimination
Affective sensation
Color vision
Visual perception
Sensation 
Visuospatial function
Visual object recognition 
Tactile graphic