Can Brain Understand The Brain?
“Biology gives you brain. Life turns it into a mind.”
-Jeffrey Eugenides, Middlesex
That was an inspiring talk by Prof .K.J. Rao*!
Topic: “ Brain Makes us Human and Chemistry Makes the Brain”!
Venue: The National College, Basavangudi, Bangalore
Date & Time: 11/07/2012 6 p.m.
Organised by: The Bangalore Science Forum
Fore-note:
While I accidentally stumbled upon the event and entered the auditorium with the
preconceived notion that the topic would be totally medical one (outside my
purview), and hence occupied a seat close to the exit door, so that I could
silently sneak out at any stage during the course of the lecture. Believe me, I was the last to exit along with
the Professor. So captivating was the talk! And so audience-friendly was Prof. Rao.
Though each slide contained obvious medical and
technical terms, the manner in which Prof. Rao synchronized it to our
brain made the talk and the evening a memorable one. What is more, I even made an effort to take
some notes. I wouldn’t call this an
article or a story. These are some of
the concepts not just academic but something which every human should be aware of those related to the parts/ functions of the brain. I have made an attempt to cull out the essentials from the mix of medico-technical stuff of the presentation, which might more sound like answers to short-notes questions in an examination. Bear with me, otherwise!
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The human brain is the centre of the human
nervous system. The important parts of
the human brain include cerebrum or cerebral cortex and the brain structures
underneath it play important role in our human emotions. The cerebellum and the brain stem are
believed to be the earliest structures which evolved into human brain.
Each half of the cerebrum, said to be the
famous and largest part of the brain (85% of the brain), has four different
lobes that each one controls: a) speech b) vision c) movement and d) ideas,
thinking and planning.
Interestingly, the weight of the human brain is
1400 grams. (Is
it the same for every body, both men and
women?).
The cerebrum is divided into two
hemispheres. The left hemisphere
controls movements on the right side of the body, receives the auditory input
for the right ear, visual input from the right half of the visual field, and
vice versa.
It is very exciting to know the growth of the
brain during pregnancy. By 40 weeks, the
brain increases in its size and complexity. The number of neurons (nerve cells)
in the brain does not increase after birth, but the links between the nerves
continue to develop.
Brain cells cannot divide and replace themselves
like other cells in the body. By the
time people enter their 60s,70s,80s and 90s, they might have lost about 5 to 20
per cent of their original tissue. That is why some older people (of course,
not all!) slow down mentally or have trouble remembering.
Human brains are ultimately high in
complexity. There are over 100 billion
neurons (can be compared to the number of stars in
the milkyway?). Each making 1000 –
10000 connections and the total connections works out to about 100
trillion - a figure beyond human comprehension.
Prof. Rao clarified that “even the most powerful
computers in the world today are crude machines compared to the exquisite
complexity of the human brain”.
A neuron makes an average 15000 connections in
adult brain. The brain is only 2 %
of our body weight; it consumes 20 % of our energy.
A bundle of neurons is known as a nerve and also known as track in the Central Nervous
System (CNS). The CNS is divided into
two parts: the brain and the spinal cord.
The spinal cord is about 45 cms long
in adult men and weighs about 35 – 40 gms. There are 10 billion neurons in it. The vertebral column that houses the spinal
cord is about 70 cms long.
The brain is fed by large arteries that carry
about 1700 ml of blood to the brain every minute. This blood supply is its only source of
nutrients and oxygen. The brain uses 20
per cent of the oxygen needs of the whole body.
If blood supply is interrupted by blood clot, brain damage will quickly
occur, resulting in a stroke. Many
small blood clots (mini-strokes) over a period of years cause cumulative damage
which is responsible for about 20% of dementia (progressive deterioration in
the ability of processing thought) in elderly.
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Beware of “drugs”! You will never be yourself again.
People on drugs are wasted all the time and don’t
grow. Being high turns off that subtle
part of life in which we process our experiences and ideas and develop insights.
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Brain waves, we get all the time.
Alpha waves – Truly relaxed; fresh creative energy brains begin to flow, fears vanish and one
experiences a sense of peace and well-being.
Theta waves – deeper relaxation and
meditation. Brain activity slows almost
to the point of sleep; restores long
forgotten memories.
Delta waves – the slowest of brainwave activity
is found during sleep and dreamless sleep; also sometimes found in
experienced meditators.
Hippocampus (involved in the formation of new memories and is also
associated with learning and emotions) is intimately involved with memory
processing and the frontal cortex (which regulates decision making, problem
solving, consciousness and emotions) with logical and rational thought. These are affected severely in Alzheimer’s
Disease patients.
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Memory is a great
gift of nature.
Working memory –
very short term memory for things being experienced now is working
memory.
Non-Declarative
memory – includes skill learning, implicit learning and habituation.
Declarative memory
and Hippocampus - Declarative memory
covers the memory of facts such as events and names, which do not need to be repeated for them to sink in.
Experiences which are destined to be laid down as long term memories are
shunted down to the hippocampus where they are held in storage for 2-3 years.
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Dreams consist
partly of a rerun of things that have happened during the day, fired up to the cortex
by the hippocampus.
Memory is created
by association between a group of neurons such that when one fires, they all
fire, producing a specific pattern.
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Alzheimer’s
disease – a brain disorder named after German physician Alois Alzheimer, who
first described it in 1906. (Parkinson’s
disease belongs to this group).
-Areas of the
brain tissue are damaged and messages do not transmit, causing the symptoms of
the disease. There is a slow but relentless destruction of nervous cells. This destruction leads to selective loss of
mental function, especially memory.
Patients with advanced Alzheimer’s disease –
Memory loss (especially for recent events), confusion, poor concentration,
disorientation and sometimes changes in personality. In later stages it may be accompanied by
aggressive behavior, depression or a tendency to wander off.
Eventually, almost complete loss of memory,
failure to recognize surroundings and loved ones, loss of language, and of the
ability to recognize and use of familiar objects. The individual becomes fully dependent for
all their basic needs.
The most tragic, isn’t
it?
My doubt: Can
Brain Understand The Brain? Appears more a paradox!
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There were plenty of feedback queries like brain vs dream, brain vs coma, brain vs epilepsy, brain vs mind, brain vs hypnosis....that comes to mind. Due to paucity of time, it is left to, probably, another session.
Thank
you, Professor, for making a person like
me who did not have an iota of an idea as to what is the inside of the
brain. You have kindled to ask for more!
______________________________________________________________________________
Prof. K.J. Rao*
Ph.D. (IIT/K)D.Sc. (IISc) F.A.Sc. F.N.A.
Education: B.Sc (Honours) Mysore
University, India (1960)
M.Sc., Mysore University,
India (1961)
PhD., I.I.T. Kanpur (1967)
D.Sc. I.I.Sc.,Bangalore, India (1988)
Prof. Rao is also associated with
authoring over 250 publications.
