Cognition

Quite simply, cognition refers to thinking. There are the obvious applications of conscious reasoning—doing taxes, playing chess, deconstructing Macbeth—but thought takes many subtler forms, such as interpreting sensory input, guiding physical actions, and empathizing with others. The old metaphor for human cognition was the computer—a logical information-processing machine.

Relationships

Love is one of the most profound emotions known to human beings. For some, romantic relationships are the most meaningful element in their lives, providing a source of fulfillment outside of ourselves. But the ability to have a healthy, loving relationship is not all innate.

Stress

Stress is simply a reaction to a stimulus that disturbs our physical or mental equilibrium. In other words, it's an omnipresent part of life. A stressful event can trigger the “fight-or-flight” response, causing hormones such as adrenaline and cortisol to surge through the body.