From songs and poems to novels and movies, love is a timeless and universal theme that has inspired artists throughout the centuries. Love is also an important aspect of our lives and it has influenced our decisions and behavior. In fact, some people’s lifelong commitment to love has shaped our world and promoted well-being on a global scale. Think of Mahatma Gandhi, Martin Luther King Jr., Maya Angelou, and Oprah Winfrey. Their selfless acts and their profoundly deep love for others are proof that if you truly care about someone, you can make their world better.

But what is love exactly? And how can you know if what you feel is the real deal?

Love is a complex emotion and it can differ from person to person. But there are some things that all love can share. For one, it is usually a combination of three components that can be visualized as the vertices of a triangle: intimacy, passion, and decision/commitment.

Psychologist Helen Fisher from Rutgers University recently published some intriguing research about this phenomenon. She and her team put 37 people madly in love into an MRI scanner and observed their brain activity. They found that when people are in love, there is a surge of dopamine in the caudate nucleus and in an ancient brain area called the ventral tegmental area. These are the parts of the brain associated with craving, motivation, and focus. In simpler terms, when we are in love, we want to be around our partner and we crave their presence.

In the early stages of romantic love, lust and attraction are strong, and this often leads to a quick decision to commit to a relationship. This can be good or bad for our long-term happiness, depending on whether lust and attraction are the primary emotions or if they are balanced by other emotions such as concern and companionate love.

It is also common for people in love to become empathetic and to want to help others. In fact, this is one of the core traits of true love. This is especially evident in the way that parents and caregivers love their children, and the way that friends and family members support their loved ones through tough times.

But as we grow older, our definitions of love can change, too. Sometimes we are no longer in a rush to take the leap of commitment, and sometimes we even fall out of love altogether. This can be painful, but it is normal and a natural part of human development.

In the end, it is up to each individual to decide whether or not what they feel is genuine love. The key is to be curious about your feelings and to see if they change over time or circumstances. If you are able to determine that what you feel is not just infatuation or toxic love bombing, then your chances of a healthy and happy future together will be much higher.

Sleep is vital for the health and well-being of humans. It plays a key role in many metabolic and regulatory functions, such as the maintenance of healthy blood pressure, glucose levels, and cholesterol, as well as the healing and repair of tissues and organs. A growing body of evidence indicates that sleep also plays important roles in memory consolidation, supporting normal immune function and healing after injury, and that it can help prevent weight gain and promote emotional stability.

In fact, without adequate sleep people have difficulty thinking, reacting, learning, and concentrating, making it difficult to make good choices or to perform well in work or school. Lack of sleep can also increase the risk of some chronic diseases and conditions, including heart disease, stroke, depression, diabetes, high blood pressure, psoriasis, Alzheimer’s disease, and cancer.

Much of what scientists know about sleep — including its stages and what happens in the brain during each stage — was learned thanks to the early sleep research done by UChicago professor Nathaniel Kleitman. His 1939 textbook, Sleep and Wakefulness, was a foundational text for the field. Kleitman founded the world’s first laboratory dedicated to sleep research and used all-night electroencephalogram (EEG) recordings to chart a sequence of brain activity during the night as he watched subjects fall asleep.

The EEG tracings during sleep show that when the body begins to prepare for sleep, the brain’s normal electrical signaling becomes irregular, with the brain’s activity shifting from rapid alpha waves to slower theta waves, and then to slow delta waves. During this phase, there are also short sequences of 11-15 Hz waves that are called sleep spindles. These rhythms appear in the thalamus and cortex, and their pattern varies between individuals. No single criterion has been identified that reliably marks the beginning of sleep.

When the brain enters REM (rapid eye movement) sleep, which occurs several times during a night’s sleep cycle, the irregular EEG patterns become even more abnormal and the body begins to act as though it were awake. That is why it is often difficult to wake someone up from this phase of sleep and they may feel drained or tired, even if they had a good night’s rest.

During this stage of sleep, the brain and body are resetting their internal clocks. The resetting is what allows us to maintain a regular, predictable wake-sleep cycle and helps regulate the circadian rhythms that govern body temperature, hunger, metabolism, growth, reproduction, and aging.

Without enough REM sleep, the body is unable to restore and repair the tissues that have been damaged during the day, which can lead to a host of health problems. Studies also show that a sufficient amount of REM sleep can help reduce the risk of cardiovascular disease by increasing good cholesterol and decreasing bad cholesterol, which decreases inflammation, and by lowering blood sugar levels and blood pressure. Getting adequate amounts of sleep is just as important for cardiovascular health as exercise, a nutritious diet, and non-smoking status.