Where do such plans come from, and how are they acted on?

Devising and carrying out plans is the realm of the top-brain system. In particular, the top parts of the frontal lobe are concerned with these functions. But how does the top brain know what is being perceived? Information about where objects are located in space is so important for making plans that it is processed directly in the top brain; we need to know where objects are located in order to decide how to move them or how to move our bodies as we seek to approach or avoid them. (In our example, without such informa­tion, you couldn’t have known how to thread your way through the crowd to reach and talk to your friend.) But we need to know more than just where objects are located—we also need to know what they are. Such information from the bottom brain goes to the top brain, allowing the top brain to use information about the nature of ob­jects being perceived.

The top part of the frontal lobe also contains numerous areas that control movements. Because our movements occur in our im­mediate environment, to program them appropriately our brains need to know where objects are located—to reach for them, step over them, run from them, and so forth. To walk over to your friend, you need to know where she is relative to your body; to talk to her, you need to know where she is facing, and you need to position yourself close enough (but not too close!) so that she can hear you easily.

The top parts of our frontal lobe can take into account the confluence of information about “what’s out there,” our emo­tional reactions to it, and our goals. They then play a crucial role in allowing us to formulate plans, make decisions, and direct attention in particular ways (in part by connections to the parietal lobes); they allow us to figure out what to do, given our goals and our emotional reactions to the unfolding events that surround us.

The bottom-brain system organizes signals from the senses, simultaneously comparing what is being perceived with all the in­formation previously stored in memory—and then uses the results of such comparisons to classify and interpret the object or event that gives rise to the input signals.

The top-brain system uses information about the surrounding environment (in combination with other sorts of information, such as emotional reactions and need for food or drink) to figure out which goals to try to achieve. It actively formulates plans, generates expectations about what should happen when a plan is executed, and then—as the plan is being carried out—compares what is happening with what was expected, adjusting the plan accordingly (for example, by adjusting your grip as the phone starts to slip from your hand).

Four Cognitive Modes

Four distinct cognitive modes emerge from how the top-brain and bottom-brain systems can interact. The degree to which each of the brain systems is used spans a continuum, ranging from highly utilized to minimally utilized. Nevertheless, for our purposes it is useful to divide the continuum into “high” and “low” categories.

Mover Mode results when the top- and bottom-brain systems are both highly utilized. When people think in this mode, they are inclined to make and act on plans (using the top-brain system) and to register the consequences of doing so (using the bottom-brain system), subsequently adjusting plans on the basis of feedback. Ac­cording to our theory, people who habitually rely on Mover Mode typically are most comfortable in positions that allow them to plan, act, and see the consequences of their actions.