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Transcript of Human Brain
Phantom Limb Syndrome
It is common for amputees to feel the vivid presence of a missing limb long after it has gone.
A remarkable ability of the brain that allows you to see even though you are totally blind.
Case Study 3 - Visual Neglect
Peggy Palmer has normal vision but half of her visual world no longer seems to matter as the result of having a stroke in the parietal lobes of her brain.
The Human Brain
The brain is the most complexly
It is made up of 100 billion
nerve cells or neurons.
Each neuron makes 1000 to 10000 contacts with other neurons in the brain.
The number of possible combinations of brain activity
exceeds the number of elementary particles in
Case study 1
Derek Steen loses one of his hands because of a motorcycle accident but he still feels the arm there. He looks down and sees nothing.
the more he thinks about it, the more it hurts. And the more it hurts, the more he thinks about it...
It turns out that even our body is something that we construct in our mind.
In the brain there is a complete map
of the surface of the body.
How do you treat pain in a body part that is missing?
Success in relieving Phantom Limb pain with a mirror box suggests that even pain can be a construct of the mind.
The phenomenon of Phantom Limbs
reveals how our brains can delude us into
being conscious of something that is not there.
Case Study 2
Graham Young's vision was affected by a road accident. He can see to the left but is blind to everything on right, in both eyes.
if you put an object in that part of the field he has no idea what
the object is. (He cannot perceive it consciously)
Yet, if you move the object, he will tell which direction it's moving!
(even though he cannot see the object)
it implies that, to some extent, we can actually manage our brains without consciousness.
Vision is not entirely seeing.
Detecting things without being aware of them.
We are not aware of things that we are not aware of.
We just don't know the extent to
which they play a part.
It turns out that from the eyeball to the higher centers of the brain, where you interpret the visual image, there are
two separate pathways.
Blind sight is surely fascinating but in a sense not that strange.
Conscious vs Unconscious
We experience blind sight all the time in our daily lives.
the parietal lobes are concerned with creating a 3D view of the world,
allowing the person to walk around, navigate, to avoid bumping into things.
When the right parietal lobe is damaged, the patient is unable to deal with the left side of the world.
And this means it is not simply a sensory problem but a problem of consciousness.
It reveals how damage to the visual centers in the brain can affect our consciousness of the world.
There are thirty areas in the back of the brain where seeing takes place. Different areas are specialized for different aspects of vision:
seeing colors, movement, form, shape, relative distance, depth,...
The visual input, as it comes, divides into two parallel streams of processing:
"How" Pathway & "What" Pathway
Case Study 4 - Capgras Delusion
David Silvera had a car accident. He is normal intellectually and is not disturbed emotionally. Everything seems fine except one delusion; He thinks his parents are imposters.
On the phone, no problem; he always recognizes his parents.
Whenever we look at an object or a face, the message reaches the temporal lobs, where it's identified, and then to a structure called the "amygdala", which is the gateway to the "limbic system" that contains the emotional centers of the brain where we generate the appropriate emotional response to whatever we are looking at.
The lack of emotional response actually leads David to this very profound delusion that his mother is not really his mother.
This absurd conclusion which defeats what his intellect is telling him, shows how closely your intellectual view of the world is linked to your basic emotional reactions to the world.
But what would happen if the emotions were to run out of control? What effects might an excess of emotion have on the way we interpret the world?
Case Study 5 - Temporal Lob Epilepsy
John Sharon has temporal lob epilepsy. His seizures are basically an electrical storm in his temporal lobes when a group of neurons starts firing at random, out of sync with rest of his brain.
One day after experiencing several severe seizures, each lasting 5 minutes, he started asking philosophical questions.
John had never been religious, yet his seizures brought him the overwhelming spiritual feelings.
Some patients with seizures in the temporal lobes have intense religious experience, intense experience of God visiting them. Sometimes it is a personal god, sometimes it is a feeling of being one with the cosmos.
Everything seems to have a special meaning which leads the patient to say "Finally I see what it's really about. I really understand God. I understand my place in the universe, in the cosmic scheme."
One possibility is that the seizure activity in the temporal lobes somehow creates all kinds of odd, strange emotions in the person's mind.
And this bizarre emotions may be interpreted by the patient as visits from another world, or God.
Maybe that's the only way he can make sense of all the strange emotions going on inside his brain.
Another possibility might be related to the temporal lobes that are wired up to deal with the world emotionally. As we walk around and interact with the world, we need some way of determining what's important, what's relevant to you versus something unimportant.
The strength of the connections between the temporal lobes and the amygdala determines how emotionally something is. (each of us has a slightly different connections between the two centers)
Now, consider what happens in temporal lobes epilepsy when you have repeated seizures.
What might be going on is an indiscriminate strengthening of all these pathways. So instead of just finding lions and tigers and mothers emotionally important, he finds everything deeply important. for example, a grain of sand, sea weed, a tree, etc. all become enriched with deep significance.
This tendency to consider cosmic significance to everything might be what we call a mystical experience or a religious experience.
These people are not crazy. They all suffered damage in tiny sections of their brains that has profoundly changed the way they perceive themselves and the world around them.
We can ask questions about religion and God and begin to approach these questions by listening to these patients, by talking with them and by studying them.
Now perhaps science will have its chance.
For centuries, philosophers have tried to understand God, consciousness and the mysteries of human nature.
And more importantly...
Why should anyone trust the big claims by religion, philosophy, or any other ideology?
How would you define a spiritual
experience? and Why would you want to
have a spiritual experience?
How would you describe the mystic journey of a LUCA?