50 Psychology Classics (48 page)

Ramachandran notes an astounding fact: “A piece of your brain the size of a grain of sand would contain one hundred thousand neurons, two million axons and one billion synapses, all ‘talking' to each other.” He details the
various parts, including the four lobes—frontal, temporal, parietal, and occipital—which form the “two halves of the walnut.” Each of these hemispheres controls movement on the opposite side of the body—the left half controls movement on our right side, and vice versa. The left hemisphere tends to be that part of the brain that “talks” all the time, whether in thought or speech—the rational aspect of consciousness. The right relates more to our emotions and a holistic awareness of life. The frontal lobes are often considered the most “human” part of the brain, where the facilities of wisdom, planning, and judgment are based.

Other features include:

The corpus callosum, a band of fibers that connects the two halves.

The medulla oblongata at the top of the spinal cord, which regulates blood pressure, heart rate, and breathing.

The thalamus, which sits at the center of the brain, and through which all the senses except smell are relayed; thought to be a primitive part of the brain.

Underneath is the hypothalamus, related to “drives” such as aggression, sex, and fear, and also to hormonal and metabolic functions.

Despite this basic knowledge, Ramachandran notes, we are still not really sure how memory and perception occur. For example, are memories housed in particular parts of the brain, or is memory more holistic, involving the whole brain? The author suggests that both explanations may be true, in that while particular parts of the brain have certain jobs, it is in understanding how they interact that we begin to get closer to comprehending what makes up “human nature.”

What does the title
Phantoms in the Brain
refer to? Ramachandran is best known for his work with people who experience phantom limbs. After an amputation or paralysis, a person will have all the normal sensations of the limb. The worst part is that people can actually experience a lot of
pain
in their phantom limbs. Ramachandran wondered how and where these phantoms were generated in the nervous system. Why does the sensation of having a limb remain “frozen” in the brain after amputation? Through experiments and work with patients, he explains phantom limb sensation thus: Essentially, the brain has a body image, a representation of itself that includes the arms and legs. When a limb is lost, it may take a while for the brain to catch up to this fact.

The conventional view is that, in shock over the loss of an arm or leg, the person engages in wishful thinking that the limb is still there, or goes into denial that it is lost. But Ramachandran points out that most of the people he sees are not neurotic. Indeed, he treated a woman, Mirabelle, who was born without arms and yet has vivid sensations of their use. This suggests that the brain is hard wired for limb coordination, and wants to enjoy that use even
when sensory information tells it there is nothing there to move. He mentions another case where a girl frequently used her fingers to do simple calculations in arithmetic—except that she was born without forearms. What usually happens when a person loses a limb is that their brain keeps sending signals to use it, but in time the feedback that there is no limb is enough for the sensations to stop. Unlike amputees, however, people actually born without arms have never received the sensory feedback from their stumps that anything has changed, so their brain can keep on believing that they have arms to use.

Anasognosia is a syndrome in which a patient, obviously sane in most respects, denies that their arm or leg has become paralyzed, but the denial happens only if it is their
left
arm or leg. What causes this disorder? Is it simply wishful thinking, and why only left limbs?

Ramachandran's explanation involves the division of labor between the two brain hemispheres. The left hemisphere works to create belief systems or models of reality. It is conformist in nature and “always tries to cling tenaciously to the way things were.” Therefore when it has new information that does not fit into the model, it employs defense mechanisms of denial or repression in order to preserve the status quo. The job of the right hemisphere, conversely, is to challenge the status quo, and look for inconsistencies and any sign of change. When the right hemisphere is damaged, the left hemisphere is free to pursue its “denials and confabulations.” Without the right's reality check, the mind wanders down a path of self-delusion.

Ramachandran's work with people living with anasognosia seems to prove the Freudian idea of defense mechanisms; that is, thoughts and behaviors whose purpose is to protect the idea we have of ourselves. Neurology's task is to discover why people rationalize and avoid reality, only it involves considerations of brain wiring instead of the psyche. Patients in denial mode are the best way to research this because their defense mechanisms are concentrated and amplified.

The brain will do anything to preserve a sense of self. This evolved perhaps because the brain and nervous system involve so many different systems and a grand illusion is necessary to tie them all together. To survive, to be social, to mate, we need to have the experience of being an autonomous being who is in charge. However, the part of us that is in charge is in fact only a small part of our whole being; the rest carries on automatically, zombie like.

Ramachandran refers to Thomas Kuhn and his landmark book
The Structure of Scientific Revolutions
, which noted that science tends to sweep the unusual
cases under the carpet until they can be fitted into established theories. But Ramachandran's view turns this on its head: We can get closer to generalities by solving the strange cases. Consider just three he discusses:

Hemi-neglect patients are indifferent to objects and events in the left side of the world, sometimes even indifferent to the left side of their own bodies. Ellen doesn't eat the food on the left of her plate, doesn't put makeup on the left side of her face, and doesn't even brush the teeth on the left side of her mouth. Though alarming to the people living with her, the condition is not uncommon and often follows strokes in the right brain, especially in the right parietal lobe.

Capgras' delusion is a rare neurological condition in which the patient comes to regard their own parents, children, spouse, or sibling as imposters. The patient can identify these people, but does not experience any emotions when looking at their faces, which leads the brain to create the assumption that they must be imposters. In neurological terms, there is a disconnection between the face recognition area (in the temporal cortex) and the amygdala (a gateway to the limbic system), which helps generate emotional responses to particular faces.

Cotard's syndrome is a bizarre condition where people believe themselves to be dead. They claim to smell their rotting flesh and see worms crawling in and out of their carcass. Ramachandran suggests this comes about through a connection failure between the sensory areas of the brain and the limbic system, which deals with emotions. Patients literally no longer feel any kind of emotion and therefore disengage from life. The only way their brain can deal with the situation is to presume that they are no longer alive.