Michio Kaku

we need a CEO to sift through them in order to simulate the future and make a nal decision. Accordingly, our brains di er from those of other animals, especially in the expanded prefrontal cortex, located just behind the forehead, which allows us to “see” into the future.

Dr. Daniel Gilbert, a Harvard psychologist, has written, “The greatest achievement of the human brain is its ability to imagine objects and episodes that do not exist in the realm of the real, and it is this ability that allows us to think about the future. As one philosopher noted, the human brain is an ‘anticipation machine,’ and ‘making the future’ is the most important thing it does.”

Using brain scans, we can even propose a candidate for the precise area of the brain where simulation of the future takes place. Neurologist Michael Gazzaniga notes that “area 10 (the internal granular layer IV), in the lateral prefrontal cortex, is almost twice as large in humans as in apes. Area 10 is involved with memory and planning, cognitive exibility, abstract thinking, initiating appropriate behavior, and inhibiting inappropriate behavior, learning rules, and picking out relevant information from what is perceived through the senses.” (For this book, we will refer to this area, in which decision making is concentrated, as the dorsolateral prefrontal cortex, although there is some overlap with other areas of the brain.)

Although animals may have a well-de ned understanding of their place in space and some have a degree of awareness of others, it is not clear if they systematically plan for the future and have an understanding of “tomorrow.” Most animals, even social animals with well-developed limbic systems, react to situations (e.g., the presence of predators or potential mates) by relying mainly on instinct, rather than systematically planning into the future.

For instance, mammals do not plan for the winter by preparing to hibernate, but largely follow instinct as the temperature drops. There is a feedback loop that regulates their hibernation. Their consciousness is dominated by messages coming in from their senses. There is no evidence that they systemically sift through various plans and schemes as they prepare to hibernate. Predators, when they use cunning and disguise to stalk an unsuspecting prey, do anticipate future events, but this planning is limited only to instinct and the duration of the hunt. Primates are adept at devising short-term plans (e.g., nding food), but there is no indication that they plan more than a few hours ahead.

Humans are di erent. Although we do rely on instinct and emotions in many situations, we also constantly analyze and evaluate information from many feedback loops. We do this by running simulations sometimes even beyond our own life span and even thousands of years into the future. The point of running simulations is to evaluate various possibilities to make the best decision to ful ll a goal. This occurs in the prefrontal cortex, which allows us to simulate the future and evaluate the possibilities in order to chart the best course of action.

This ability evolved for several reasons. First, having the ability to peer into the future has enormous evolutionary bene ts, such as evading predators and nding food and mates. Second, it allows us to choose among several di erent outcomes and to select the