Brain's structure:
Though brain is just like another organ in the body, it is quite different than organs. The difference is in various terms. Brain is the only organ that controls other organs. Subsequently, that derives another difference. Unlike heart, lungs, liver, etc each of which is responsible for one activity, brain takes the responsibility of various actions like hearing, vision, touch, smell, taste, etc. So I would say that it's a collection of organs that takes the overall control of the whole nervous system that connects our whole body. If you look at the brain from outside, the different portions of brain can be seen. Please refer the below picture that indicates the portions and responsibilities.
Brain's cerebrum is actually split into two pieces; each sits side by side and their shape is like hemisphere. Hence they are termed as left hemisphere and right hemisphere. Mysteriously, the fact is left hemisphere is responsible for the whole right side of our body such as right arm, right leg, etc... and the right hemisphere is responsible for the left side of the body. Similar way, our optical nerves from eyes cross over each other and connects with the opposite portions of the occipital lobe.
Apart from these each hemisphere remains sole responsible for other activities. For example, the left brain focused on detail. This would make it the natural home for all those mental skills that need us to act in a series of discrete steps or fix on a particular fragment of what we perceive--skills such as recognising a friend's face in a crowd or "lining up" words to make a sentence. By contrast, the right brain concentrated on the broad, background picture. The researchers believed it had a panoramic focus that made it good at seeing general connections; this hemisphere was best able to represent the relative position of objects in space and to handle the emotional and metaphorical aspects of speech.
Researches say that from childhood to Adulthood, the brain under goes vast number of changes. It grows in terms of size as well as knowledge. If you look at the brains of a child and an adult side by side, you can clearly see two important differences. Please refer the below pictures.
1. A child's cerebrum has more 'grey matter' than the adult's developed brain. It has been found that the cerebrum gains as more neurons are trained and used and more knowledge is stored.
2. Since the neurons are more trained in adults, their brain shows more activity than a child's brain.
If you look inside the brain, kind of zoom in, what you see is nothing but the network of millions of neurons. As you in the below picture, there are branches that connect all the different portions of the brains such as cortex and lobes. There is also one more important portion of brain that links the whole nervous system to the endocrine system via the pituitary gland. It's called as hypothalamus and it contains a number of small nuclei with a variety of functions. The hypothalamus controls body temperature, hunger, thirst, fatigue, and circadian cycles.
Brain's activities:
We can classify the brain's activities into four basic actions such as receiving signals from organs, sending signals back to organs, analyze the situation and finally storing into memory. Now lets explore them in detail.
1. Receives signals:
Brain receives signals from the sensory organs like hands, legs, ears, eyes, nose and mouth. That's how we realize what we do, what we hear, what we see, what we smell and what we eat. Every time, you act, your organ sends signals or messages to the brain through nervous system. Specific portion which is responsible for that particular task takes up the signals for further processing.
2. Sends signals:
Once brain receives the signals from the sensory organs, it starts to process them through it's axons and neurons and sends specific commands to the organs in return. Hence we take our hands off soon after we touch the fire. These signals are basically passes through blood. Heart also participates in the brain's activity by pumping enough blood for brain to do it's job with no problems. That's why people who are tired stop moving because brain doesn't send signals to the organs to act or react. Similarly dead person doesn't move or even blink as brain stops receiving signals through blood as heart stops pumping it to the brain.
3. Analyze signals:
Brain is capable of doing various kinds of analysis such as Logical reasoning, Pattern recognition, memory, mathematical calculations, etc. However, brain does not properly analyze every signal before it sends the commands. It depends on how quick the reaction is required or command needs to be executed. Let me explain this here. For example, lets say you are shown a picture of a smiling baby and your brain tells you that it's a smiling baby and probably put a smile on your face! So, here your brain receives the signals, process them and returns the commands.
Signals come via blood and pass through the brain's neural network and fire electrical impulses at various intervals synchronously, simultaneously, periodically etc... and that creates a specific pattern. When brain detects such a pattern of action, it goes back to its memory and tries to find matching pattern of action from its previous experiences. When it finds, it goes further to find what was the desired behavior or pattern of reaction for such a pattern of action. Then it finds the pattern of reaction and returns them in terms of signals back to the respective organs through blood. When it doesn't find a desired pattern of reaction, that's when we stand still by not knowing what to do or how to react to such actions or situations. Sometimes this analysis or pattern matching process doesn't happen on time but a little later or after sending emergency signals.
Lets say that you are watching a 3D movie and suddenly there is a knife thrown into your eyes via 3D projection. You would immediately try to move away from it as it's gonna hit you for real! Why is that? Even though you know it's just a movie, your brain still thinks it would hurt you and that's why it sends signals to your body to move away from it. At this point of time, your brain doesn't do any analysis on what is going on rather it goes under defensive mode. However, after the reaction you come back to normal as your brain learns that it's just a movie 'once again'. Brain always prefer to come up with faster and average results than the perfect answer later.
4. Stores in memory:
When brain observes a situation, it records the same in to its memory but depends on the intensity of the observation on each item or detail of the situation, it records that specific detail in the active portions of the neural network. Other less-interesting details are stored but eventually lost over time as if that particular pattern is not reproduced frequently or refreshed over time. Hence, the difference comes between memorizing and just watching. Irrespective of different hemispheres acts on observing different attributes of a situation, underneath the information is stored in the form of patterns. Hence each and every bit of information is shared across various number of neurons in the form of patterns of impulses.
In my next posts, we will explore how information is processed by the neural network inside our brain.
No comments:
Post a Comment