The Playground of Inspiration

                                      Chapter – 2 (When Awake, We Perceive the World)

Now that we’ve discussed relativity in the first chapter, it’s time to explore the major states of the human brain one by one.

Main States of the Human Brain: The common states of the human brain and the information coming through the five senses are mainly controlled by the midbrain, the cerebral cortex, and the thalamus, which is situated between them.

Relaxed Awake State: The cerebral cortex is divided into several lobes—the frontal, parietal, occipital, and temporal lobes. In the awake but relaxed (not alert) state, a special kind of brain wave called an “alpha wave” (frequency 8 – 12 Hz) is produced from the occipital lobe. With eyes closed, more alpha waves are generated. At the front of the frontal lobe lies the “prefrontal cortex,” whose central executive part mainly assists us in making logical and intuitive decisions or imagining things by using information from short-term memory. In this state, the central executive part of the prefrontal cortex remains inert. Do you like to just “laze around”? In everyday Bengali, what we call “lazing around” refers to this state of the brain.

I’ve already mentioned “short-term memory.” To make this clearer, here’s an example: in order to understand the meaning of the sentence you are reading right now, you need to remember the beginning of the sentence as you reach the end. Your brain’s short-term memory does this keeping—holding small amounts of information for a short period (10 to 15 seconds, or sometimes up to a minute). Near the visual cortex in the occipital lobe of the cerebral cortex is a neural loop (a set of neurons connected in a sequence to transfer data from place to place for a specific task), which serves as the short-term memory for visual data. There’s also a phonological neural loop that works with “Broca’s area” in the frontal lobe to serve as short-term memory for audio or language data.

Alert Awake State: As the human brain transitions from a relaxed state to a more alert one while awake, higher frequency “beta waves” (12.5 – 28 Hz) begin to be produced and alpha waves cease. In this state, the central executive part of the prefrontal cortex starts to become active.

In our nervous system, the chemicals that carry information from one neuron to another are called “neurotransmitters.” Endorphin, dopamine, oxytocin, and serotonin—these four together are known as the neurotransmitter quartet, which generates the “feel good factor” in our perceptions. When you see a plate of biryani in front of you and feel pleasure, thank the secretion of endorphins in your brain. Perhaps you have fallen in love—the day that happened, your brain was bathed in dopamine. When you think about someone special or make eye contact with them, and you feel a surge of emotion, that’s oxytocin at work. On the other hand, after watching a horror film or witnessing a traumatic event, the reduced secretion of serotonin leads to a creeping sense of “survival crisis” in your perceptions.

When you unexpectedly succeed in something you rarely do well at, the small joy you get actually increases your skill in that area without you realizing it. This is because the right amount of neurotransmitter quartet enhances the activity of your prefrontal cortex. Yet an excess of these neurotransmitters can partially or entirely deactivate the prefrontal cortex. That’s why, no matter how big a success is, excessive excitement is not at all good for your brain’s health.