As an example, Dr. Blanke described the case Of a 22-year.01d student who had electrodes implanted into the left hemisphere of her brain in 2004. "We were checking language areas,- Dr. Blanke said. The woman suddenly turned her head to the right. That made no sense, he said, because the electrode was nowhere near areas involved in the control of movement. Instead. the current was stimulating the angular gyrus, which blends vision with body sense.
Dr. Blanke applied the current again. Again, the woman turned her head to the right. "Why are you doing this?" he asked.
The woman replied that she had a weird sensation that another person was lying beneath her on the bed. The figure. she said, felt like a "shadow" that did not speak or move: it was young, more like a man than a woman, and it wanted to interfere with her.
When Dr. Blanke turned off the current, the woman stopped looking to the right, and said the strange presence had gone away. Each time he reapplied the current, she once again turned her head to try to see the shadow figure.
When the woman sat up, leaned forward and hugged her knees. she said that she felt as if the Shadow man was also sitting and that he was clasping her in his arms. She said it felt unpleasant. When She held a card in her right hand, she reported that the shadow figure tried to take it from her. "He doesn't want me to read," she said.
Because the presence closely simulated the patient's body posture and position, Dr. Blanke concluded that the patient was experiencing an unusual perception of her own body, as a double. But for reasons that scientists have not been able to explain, he said, she did not recognize that it was her own body she was sensing.