SHADES OF GIL HAMILTON: Woman has developed an imaginary, but useful, third arm. “After having a stroke, a 64-year-old woman reports that she now has a ‘pale, milky-white and translucent third arm’ that she can use to scratch itchy parts of her body . . . The woman underwent an MRI and when doctors asked her to move her imaginary third limb, her brain responded as if she really had the arm. Her visual cortex activity also indicated that she saw the arm.”