She was struck by the sequence of her hallucinations—that they had gone from simple and unformed to more complex, and then back to simple before disappearing. “It’s like they moved up the brain, then down again,” she said. She was struck by how things she had seen could change into similar forms: octagons turning into snowflakes, blobs into leaves, and perhaps gulls into Olympic athletes. She observed that, in two instances, she had hallucinated something she had seen shortly before: the neurologist’s Star of David and the sailor-boy stickers. She noted a tendency to “multiplication”—bunches of daffodils, fields of flowers, octagons galore, snowflakes, leaves, gulls, scores of Christmas bells, and multiple copies of the sailor-boy stickers. She wondered whether the fact that she was a deeply religious Catholic who prayed several times a day had played a part in her seeing a hallucination of praying hands. She was struck by the way in which the silvery leaves she was seeing instantly turned reddish brown when her niece said, “The leaves are changing.” She thought the Olympic runner might have been provoked by the fact that the 2008 Olympic Games were coming up, with constant previews on television. I found it impressive and moving that this old lady, curious and intelligent, though not intellectual, would observe her own hallucinations so calmly and thoughtfully and, without being prompted, raise virtually all the questions a neurologist might ask about them.
If one loses half the visual field from a stroke or other injury, one may or may not be aware of the loss. Monroe Cole, a neurologist, became aware of his own field loss only by doing a neurological exam on himself after his coronary bypass surgery. He was so surprised by his lack of awareness of this deficit that he published a paper about it. “Even intelligent patients,” he wrote, “often are surprised when a hemianopia is demonstrated, despite the fact that it has been demonstrated on numerous examinations.”
The day after his surgery, Cole began to have hallucinations, in the blind half of his visual field, of people (most of whom he recognized), dogs, and horses. These apparitions did not frighten him; they “moved, danced and swirled, but their purpose was unclear.” Often he hallucinated “a pony with his head cradled in my right arm”; he recognized this as his granddaughter’s pony, but as with many of his hallucinations, “the colour was wrong.” He always realized that these visions were unreal.
In a 1976 paper, the neurologist James Lance provided rich descriptions of thirteen hemianopic patients, and he emphasized that their hallucinations were always recognized as such, if only by their absurdity or irrelevance: giraffes and hippopotamuses sitting on one side of a pillow, visions of spacemen or Roman soldiers to one side, and so on. Other physicians have made similar reports; none of their patients ever confuses such hallucinations with reality.
I was therefore surprised and intrigued to receive the following letter from a physician in England, about his eighty-six-year-old father, Gordon H., who had long-standing glaucoma and macular degeneration. He had never had hallucinations before, but recently he had had a small stroke affecting his right occipital lobe. He was “quite sane and largely intellectually undiminished,” his son wrote, but
he has not recovered vision and retains a left hemianopia. He has, however, little awareness of his visual loss as his brain appears to fill in the missing parts.
Interestingly, though, his visual hallucinations / filling in always seem to be context-sensitive or
Gordon H.’s normal visual perception to the right side, one might think, by its normalcy and detail, would immediately show up the relative poverty of the mental construct, the hallucination, on the left. But, his son asserts, he cannot tell one from the other—there is no sense of a boundary; the two halves seem continuous. Mr. H.’s case is unique, to my knowledge.52 He has none of the outlandish, obviously out-of-context hallucinations commonly reported in hemianopia. His hallucinations blend perfectly well with his environment and seem to “complete” his missing perception.
