Beyond re-membering: Phantom sensations of congenitally absent limbs

• DOI: 10.1073/pnas.100510697
• Publication Date: 2002-07-26T14:38:21Z
• Authors: Peter Brugger; Spyros S. Kollias; René M. Müri; Gérard Crelier; Marie-Claude Hepp...; Marianne Regard
• Keywords: Phantom limb; Premotor cortex; Neurophysiology

Phantom limbs are traditionally conceptualized as the phenomenal persistence of a body part after deafferentation. Previous clinical observations subjects with phantoms congenitally absent not compatible this view, but, in absence experimental work, neural basis such “aplasic phantoms” has remained enigmatic. In paper, we report series behavioral, imaging, and neurophysiological experiments university-educated woman born without forearms legs, who experiences vivid phantom sensations all four limbs. Visuokinesthetic integration tachistoscopically presented drawings hands feet indicated an intact somatic representation these parts. Functional magnetic resonance imaging hand movements showed no activation primary sensorimotor areas, but premotor parietal cortex bilaterally. Movements existing upper arms produced expanding into territories deprived afferences efferences. Transcranial stimulation consistently elicited contralateral fingers hand. addition, evoked similar sensations, albeit motor potentials stump. These data indicate that parts have never been physically developed can be represented sensory cortical areas. Both genetic epigenetic factors, habitual observation other people moving their limbs, may contribute to conscious experience aplasic phantoms.