User:Nafiaheme

What is Psychology?

Psychology is the scientific study of the mind and behaviour. Psychology includes the study of conscious and unconscious phenomena, as well as feeling and thought. Psychologists explore behaviour and mental process, including perception, cognition, attention, emotion, intelligence, subjective experiences, motivation, brain functioning and personality. The word ‘psychology’ derives from Greek roots meaning study of the psyche, or soul. In 1890, William James defined psychology as- “the science of mental life, both of its phenomena and their conditions.”

“I think psychology is the most interesting of all fields. It’s the most interesting because it’s about us. It’s about the most important and intimate aspects of our lives. It’s about language and perception, it’s about our memory of things,it’s about our dreams, love, hate, it’s about morality, our sense of right and wrong, it’s about when things go wrong as in depression, our anxiety. It’s about happiness, it’s about everything that matters to us.”

-Paul Bloom,Ph.d Psychology professor, Yale University

I have a great fascination for psychology, especially for the fields of minds, behaviour, the unconscious mind, the changes within us. Now recently I’ve started doing some ‘research’ work on one of my fields of interest; Dream. For dream, we need to know about the thing named ‘sleep’ first. Cause, dream comes from sleep. Without knowing the process of sleep, we won’t be able to have a good idea about dreams. So, let’s start. Shall we?

Chapter: Sleep

What is sleep?

Sleep is a state where awareness to environmental stimuli is reduced. Sleep is different from states of coma, hibernation and death by the fact that it can be rapidly reversed. Why do we feel sleepy? Very normal question- when do we humans sleep? The answer is of course-at night time. Normally, if we don’t have any other problem or anything-we sleep, or feel sleepy at night. Of course normally/normal people don’t get that sleep at day time(if there is no other issue/problem). We all know that. Now, the question is, why do we feel sleepy when it’s night? Why do we start yawning opening our big mouth why do we feel that our eye lids are becoming heavier and heavier, when it’s night time? It mainly happens for the Circadian Rhythm.

Mini Q. : What is circadian rhythm? Circadian rhythms are 24-hour cycles that are part of the body’s internal clock, running in the background to carry out essential functions and processes. One of the most important and well-known circadian rhythms is the sleep-wake cycle.

Well, how does this circadian rhythm work in case of our ‘sleep’? -Circadian rhythms help determine our sleep patterns. The body's master clock, or SCN, controls the production of melatonin, a hormone that makes you sleepy. It receives information about incoming light from the optic nerves, which relay information from the eyes to the brain. So, we came to know that circadian rhythms are the regulator of our sleep-awake function. From above, we also came to know about a new thing, Melatonin. It’s said that due to this circadian rhythm, a thing named “melatonin” is produced, which makes us sleepy. So, we can say that for the functioning of the circadian rhythms, melatonin is produced and for its production, we feel sleepy(at night). Now, the question arises- why and how melatonin is produced, and what has this got, that we feel sleepy! Well, it’s time to know about this new thing.

What is melatonin?

Melatonin is a hormone that your brain produces in response to darkness. It helps with the timing of your circadian rhythms (24-hour internal clock) and with sleep. Being exposed to light at night can block melatonin production.

How is it produced?

Melatonin is a natural hormone3 that is produced by the pineal gland in the brain and then released into the bloodstream.

Mini Q.: What is the pineal gland?

The pineal gland is a small, pea-shaped gland in the brain. Actually its functions aren’t fully known by researchers/scientists. But it’s popularly known for mainly the production of melatonin, which plays roles in regulating sleep patterns.

Well, melatonin is produced due to darkness. That is, darkness prompts the pineal gland to start producing melatonin. Whereas, light causes that production to stop.

Why is it produced?

Melatonin is produced naturally from the amino acid tryptophan(?) by the pineal gland at night time. It is produced from there because of the detection of the brain that it’s dark now-means night time; so, time to produce melatonin!

When is it produced?

In humans and most diurnal mammals, melatonin is secreted at night.

Why melatonin is produced only at night?

During the day, the suprachiasmatic nuclei(one kind of nucleus in brain) stops melatonin production by sending inhibitory messages to the pineal gland. At night, however, the suprachiasmatic nuclei are less active and the inhibition exerted during the day is reduced resulting in melatonin production by the pineal gland.

What is the role of melatonin in sleep?

Melatonin, the hormone produced by the pineal gland at night, serves as a time cue to the biological clock and promotes sleep anticipation in the brain default mode network (DMN); these effects may explain the increase in sleep propensity in circadian rhythm.