Paul Bach-y-Rita’s research was inspired by his personal family history. In 1959 his father had a stroke that yielded massive damage to his brain leaving him mostly paralysed and resulting in loss of speech. At that time, psychological functions were still believed to be strictly localized and hard-wired into specic areas of the brain, so the paralysis and other impairments were believed to be permanent. However, Paul’s brother George did not give up and devised his own rehabilitation programme for his father, turning daily routines into exercises. Over several years, his father restored most of the motor functions and regained speech, a recovery that was named unprecedented.

From the TOK point of view, this is an example of how personal knowledge can aect shared knowledge within a discipline.