Professor Ramachandran opened by describing these syndromes, both of which were traditionally psychological, but yet for which he had found neuroscientific explanations.

Capgras's Syndrome

A most usual circumstance surrounding patients who have developed Capgras' syndrome would be that of a car-accident-induced coma. Upon waking, the patient would see a loved one, most often his mother, but then not recognize her as his mother. He would instead accuse her of impostering his mother.

A Freudian interpretation of this syndrome would be that the denial is caused by the uncovering of a previously repressed sexual attraction of the patient to his mother. Freudians argue that the patient had unconsciously suppressed his feelings toward his mother. Upon undergoing trauma, the feelings of sexual attraction surfaced. Faced with this unacceptable circumstance, the patient would then rather deny the identity of his mother rather than acknowledge the new-found sexual attraction to her.

Not surprisingly, Dr. Ramachandran's research has proved that theory absurd. Through studying the damage in the patients' brains and other clinical tests, he has come up with another explanation pointing to the amygdala as a cause of the syndrome.

The amygdala is a part of the limbic system which is responsible for gauging responses to emotion in the brain. When the amygdala is active, it causes physiological changes, like sweating, to occur. What in fact happened to the patient is that his connection between the area which causes emotion to the area that senses emotion was severed.

The patient knew the woman was his mother, but when he felt no emotion toward her, that caused a great psychological disparity for him. He decided to deny her identity because it was inconceivable to him that he did not have his usual emotional reactions. This has been so far the most plausible explanation for the psychological phenomenon that has puzzled researchers for years.

I Sting, You . . . Giggle??!

Professor Ramachadran encountered a patient, who when pricked with a needle, would giggle. "I feel the pain, Doctor," said the patient, "but it just seems so funny to me."

Humor and laughter is one trait that is found cross-culturally, with the exception of Germans <uproaring laugher>. It is believed to be caused when a person's expectations take on a twist. For example, in slapstick comedy, a person would suffer a traumatic blow to the head. The audience would start laughing if the person just dusts himself off and continues on without injury. This is because of the paradigm shift away from what we normally expect.

Pain is also governed by two separate areas. One part of the brain senses pain, and the other reacts to it. What happened in this woman was that a severing of her insulus threw her pain reaction system out of sync. She felt the pain, but did not react to it at all. The disparity between what she expected and what happened made her laugh. This seemingly odd reaction was at once simply explained by a neurological phenomenon.

Earlier this century, Dr. Wilder Penfield discovered that certain areas of the brain mapped directly body parts. The correlation in human beings is shown in the diagram below.

In experimenting with monkeys, it was shown that if one severs the nerves from its spinal cord to its hand, stimulation of its face would cause electrodes in the hand-region of its brain to light up.

Studies using human subjects who claimed that they could still feel their amputated limbs as "phantom limbs" showed the same result: stimulation of certain face regions would cause the patient to feel stimulation to his phantom limb. Dr. Ramachandran shows a videotape of him probing his patient with a Q-Tip and asking him what he feels. The patient would very specifically feel his phantom thumb, phantom index finger, phantom pinky, etc. across very defined boundaries on his face. When Dr. Ramachandran moved a Q-Tip across his jawline, the patient reported feeling something rubbing across his phantom knuckles.

Dr. Ramachandran attributes this puzzling phenomenon of phantom limbs to the following theory. When the hand is amputated, that particular region of the brain no longer has any stimulation. Because of the inactivity, nerves from regions surrounding the hand region, namely the face and upper arm regions according to the Penfield diagram, would invade this inactive area. When specific areas of the face or arm is touched, it would send signals to the correct regions and to the incorrect former hand region. The rest of the brain interprets this stimulation as actually coming from the hand. Massive reorganization of the adult brain has happened.

Paralyzed phantom limbs

Some of Dr. Ramachandran's patients have claimed that their phantom limbs are paralyzed. How could this oxymoron occur? If the patient has no limb, it cannot very well be paralyzed! Dr. Ramachandran calls this phenomenon learned paralysis. The patients' limbs were paralyzed in a sling for a while before it got amputated. In this period, the brain had gotten used to the disobedience of the limb to its signals. When the limb did get removed, the brain never had a chance to undo its brainwashing. It turns out that visual feedback is an extraordinarily important factor in changing the behavior of the brain.

Virtual reality technology seemed like a viable option to help these patients receive visual feedback from their brain commands, but this option can easily cost the clinic a few million dollars. Dr. Ramachandran found a $5 solution. He constructed a box with a mirror inside in which the patient will place his "hands." While looking inside the box (on the mirrored side, of course), Dr. Ramachandran instructed him to pretend he was conducting an orchestra, waving his hands in symmetric motions. "Oh my God, Doctor, my phantom limb is moving!" exclaimed the patient. The illusion of his hand and its reflection was compelling enough to make him believe he was seeing his missing limb. The box gave the patient the visual feedback he needed.

This describes the phenomenon where the patient denies the existence of the left (or right) side of her visual world. The entire left (or right) side of the visual field is non-existent. The patient would eat off only the right side of her plate, etc.

Dr. Ramachandran experimented with mirrors to see if he can manipulate and rid the neglect. He placed a pencil left of the patient, and a mirror to the right of the patient. He asked the patient to take the pencil and write his name. Instead of using his intrinsic knowledge about the nature of mirrors, and reaching towards his left for the pencil, he peered behind the mirror, felt behind it, and then tried to reach inside the mirror. Even when he couldn't, the patient would not stop probing at the mirror and turn towards his left side. To him, the left side has ceased to exist in his world. He had to manipulate his belief system about mirrors and reflection to accommodate for this new oddity. This is known as the looking-glass syndrome.

"I just called it that to piss off my philosopher friends."

This is what Dr. Ramachandran calls the experimentation on someone's belief system. In particular, he had two particular case studies where a stroke patient denies her paralysis to her left side. In fact, about 5% of all stroke patients deny their paralysis for a period of time.

Case Study:

This patient was completely clear on her facts about this world. She knew that she had had a stroke, that she was in a hospital, and that she was talking to a doctor about her stroke. But when asked questions about her ability to move her paralyzed side, she showed denial.

"Are your hands equally strong?"
"Yes, they are, Doctor."

"Can you clap with your hands? Show me."
"Sure, Doctor." The patient proceeds to wave one hand like she was clapping.

Some people may claim that this denial is tied to neglect syndrome, but Dr. Ramachandran devised two experiments to debunk this theory.

The first was to tell the patient to remain still, then leave the room. Upon returning, he exclaimed to the patient, "Hey, you moved your left arm!" The patient agreed with him.

In the second experiment, he asked the patient to glove his good hand, then to put it inside a box. He told him to tap his hand in time with the metronom. The patient complied. While the patient was not looking, he uncovered his assistant's steady, gloved hand and covered the patient's hand. To the patient, his hand suddenly ceased to tap even though he is actually tapping his hand. When Dr. Ramachandran confronted him with this discrepancy, he said, "Doctor, I do not like taking orders. That's why I'm not tapping." Since this occurred in reference to the good side of his body, it demolishes the theory that he has left-side neglect syndrome.

Dr. Ramachandran discovered that in both cases, the patients were unable to recognize the discrepancy between what their brains told them to do and what they saw was happening. Contrary to previous psychological explanations for paralysis denial, he showed that the patients did not limit their denial to their paralysis. As was shown by the gloved hand incident, the patients denied any discrepancy.

He believes that the disorder is caused by a malfunction in the patient's right hemisphere of the brain (since the patients experienced left paralysis). The right hemisphere is responsible for descrepancy detection, while the left hemisphere is responsible for filling in gaps between confronting ideas. For example, the left hemisphere would smooth out the irregularities in your perceptions. With the stroke, the patients only regularized their ideas, without detecting large discrepancies with their right hemispheres. Hence, everything that they saw made sense to them.

Even when the patients did come to the consensus that they were actually paralyzed, they again denied that they used to deny their paralysis. "Doctor, I did say I couldn't move my left side. I never denied it. Why would I?"

With a few more case studies testing out the above theory, Dr. Ramachandran ended his lecture.

Notes prepared by Rhys Cheung