Showing posts with label brain. Show all posts
Showing posts with label brain. Show all posts

Wednesday, August 11, 2010

The secret of the blind spot in our vision

All of us have a blind spot- of one kind or another- towards another person or an activity. Having a blind spot means that you do not really understand the full meaning of that person or activity- particularly if a bad influence is involved. When you drive, your blind spot is behind you to the right or left- this is literally the dangerous zone in which you cannot see other drivers. There is also a blind spot in your field of vision. Everyone can find it with a simple test. Close your left eye, and, with your right eye, look at the first letter on the left of a line of text on this page. Move your index finger along the line towards the right focus on the letter and concentrate on your finger at the same time. Your fingertip will ‘disappear’ and then re emerges.
This phenomenon has been known for centuries, and many researchers have studied the blind spot. Essentially, the blind spot occurs where the optic nerve leaves the eye, and there are no light sensitive cells. At this point, we gave a gap in our field of vision.

 The interesting thing is not that this spot exists but rather the fact that we are not aware of it. Under normal circumstances we see with both our eyes. As they are always moving and looking at an object from different angles, they can compensate for the gap. But even if we only look with one eye, we do not notice the blind spot. The reason for this lies in the way brain processes information.
On the very first stop along our mental information highway, the corresponding area of our field of vision is simply filled in with something similar to the environment- when reading those lines it would be letters. Such blanks can also be found in our thinking processes. When we cannot think of a simple and quick solution to a question or problem, we generally say something like ‘just didn’t come to mind’

Saturday, June 12, 2010

How brain interpret the colours emotions and images

The Swiss psychiatrist Herman Rorschach used ink blots to assess the mental state of his patients. In 1921, he developed the famous ink blot test which was named after him. Today, psychologists still use the Rorschach test to uncover hidden emotions and experiences. The underlying principle of the test is easy to grasp; the viewer looks at random ink blots and describes what he or she sees but only after the person who is carrying out the test has told the patient that there is no such thing as a right or wrong interpretation.
The patients personal interpretation of the ink blots reveals a great deal about his or her psyche for example, a particular blot looks like a ravenous monster in the imagination of the observer, then such an interpretation can point to hidden fears that may be lurking deep in the psyche.

  The Thematic Apperception Test uses different images to the Rorschach test. In this case, the patient is presented with pictures of ambiguous scenes, which he or she uses to make up a story. Thus, a person who appears neutral in the picture can be used to make a sad or a funny story. Form this, the therapist reads the emotional condition of the patient and gets clues regarding deeper problems. Critics of these so called projective tests argue that psychologists strongly influence their patients in their interpretations of the test results. In fact, it is a psychologist’s skill and experience that plays the decisive role in discussions with a patient. Respectable therapists never rely completely on the results of tests such as the TAT or Rorschach.

  Every time we go to the cinema, our senses are deceived. When Hero knocks a villain down with a well placed blow, the magic of technology is much faster than our perception. In the cinema, moving pictures are created by the projection of a sequence of individual images, known as frames about 25 frames per second. Our eyes are lazy, though, for they cannot register the short breaks between the individual frames of a film.
 The spectacular neon advertising signs of casinos in Las Vegas or the grand circus deceive our grey cells in a similar manner. Clever programming ensures that, at night, the neon signs light up in certain sequences, thus conveying the illusion that the lights are moving. Sometimes the objects appear to be moving when they are in fact at rest. For example if you are waiting at a red signal in the traffic, suddenly you get a fright, as your car appears to be moving backwards. You step on the brake pedal, but nothing happens. Then you see that, in fact, the car next to you has simply moved forward because of the traffic light turned green.

Sunday, May 16, 2010

How reality confuses the brain

The way we perceive things depends on our experiences. If we have not already stored something our memory, the brain might store new information in the wrong compartment; it might even take us for a ride. We encounter situations where the brain plays tricks on us, simply because our grey cells respond automatically to experiences and expectations. We all know about mirages, the optical illusions which can lure thirsty desert travelers to disaster. Mirages make us to think we see expanses of water, or they make remote parts of a landscape seem much closer than they really are. Often mirages appear on the high way, making us think that the road ahead is slick with water.

Such apparitions can be explained through reference to conditions in the atmosphere, but our perception can also be deceived when the brain malfunctions. This can happen as a side effect of certain illnesses, hallucinations or the influence of drugs. Often, such malfunctions can make you see strange things. A typical example is the white mice that alcoholics may see during the first phase of withdrawal from alcohol. In a wider sense, metal delusions can also be counted among these brain deceptions. Delusions include persecution complexes, excessive jealousy or delusions of grandeur. They stem from the beliefs which are out of touch with reality or false images a person might have about his or her identity.

Friday, February 26, 2010

The Brain, Store house of Memory Part V

Complicated switching mechanisms of Brain:

Research has found that a central role in long term memory is played by an area called the Hippocampus, which is located in the temporal lobe. All new information must pass through the hippocampus, and it retains these impressions for up to several weeks before passing them on to areas in the cortex were they permanently recorded. In these cortical areas, memories are connected with specific emotions.

The hippocampus is closely linked to the brain limbic system one of the keys to our emotion world. The front temporal lobe contains areas that are responsible for short term memory. The so called reticular formation, situated between the brain and the spinal cord, contributes to wakefulness and attention, which are vital for both active and passive learning, as well as the active recall of memories. The cerebellum situated in the rear cranial cavity, harbors those memories that are necessary for conditioned or acquired reflexes. It also plays a role in maintaining the body’s equilibrium.

At present, we posses only fragmentary knowledge about how the mechanisms of memory retention and recall actually work. It is clear that our nerve cells name thousands of connection which are known as synapses. These are specifically re formed or re activated when mental processes occur. Together with the arrangement of special groups of nerve cells, the synapses create a neuron network for storing information. But the actual formation of memories is still poorly understood, and remains a subject for future study.

The Brain, Store house of Memory Part IV

Data stored and retrived from the senses:

The explanation for this lies in the huge variety of messages received by the memory. Every second of the day, we are busy probing our environment though our five senses. From the outer ear to the retina, the tip of the tongue, the mucous membrane inside the nose or the surface of our skin, special sensory perceptions is then linked to a large number of previous experiences. The brain has several ‘libraries’ where impressions from the senses are ordered and stored and it is these that determine our memories. There is a library for images, for taste impressions, colors, words, music, shapes and smells.

Many of our capacities – such as vision touch or smell- are processed in specialized regions of the brain. There are also extended areas of the brain know as areas of association, whose task is to evaluate and associate sensory perceptions. Even if we cannot directly remember our first taste of milk or the first time we saw a dog or cat, new stimulation through similar events is usually enough t refresh our memory. They associative pathways reactivate the formerly activated areas of the brain and enable us ot recall the past.

Advances in medial imaging technology have provided a much more detailed picture of how the brain functions. These advances now permit scientists to connect retain areas of the brain to certain memory tasks, an ability that is especially useful for patients suffering from loss of memory, epilepsy or memory impairments.


The Brain, Store house of Memory Part III

Scrects of Super brains of the Genious!

Along with the constant processing and discarding of information, there are many thousands of pieces of knowledge and memories that we will retain for ever. These pieces of data have been consigned to our long term memory, a data bank that examines and stores selected information for long term recording. The long term memory ensures that these pieces of information will always be there for us.

The long term memory works by first checking the new elements for their significance, them admitting them in proportions to how often they are repeated. This is why so called swatting, or memorization- the apparently endless repletion of what ever has to be learned- is not a torture invented by cruel teachers, but is one of the basic principles of memory retention. In many cases of extraordinary memory, the secret is simply well trained abilities. But we do need certain inherited talents if we wish to compete with the likes of Bhandata Vicitsara or Hideaki Tomoyori.

After a period of three years most people only retain abut a tenth of several hundred pieces of stored information. The remainder usually stays in their memory until the end of their lives. But to understand this process better, we need to examine where these messages are placed while they are waiting to be recalled.

The physical layout of the human memory is complicated, since our memory is not localized in one single area of the brain. This can be seen in patients who suffer from memory disturbances but not complete memory loss. Many people forget what they did the previous evening or a few hours ago- in extreme cases, even a few minutes ago. Other people cannot recall entire periods of their lives. All memory malfunctions indicate that events affection us activate several areas of the brain.


The Brain, Store house of Memory Part II

Saving data in the Brain:
Whether it is learning to read, remembering our first love, recognizing an aroma or noting a telephone number, not a single moment in our lives escapes our memory; even dreams can be partially recalled from sleep. From the moment of birth- and even before then- our memory is constantly registering, sorting and ordering the tiniest pieces of information that it considers worth saving. Thanks to this valuable ability, we are able to take note of our experiences and remember them.

Information can be held in the memory simply forgotten or fade away with time. The key is our consciously increased capacity for retention- in other words, how much attention we devote to it without this capacity we data passing the nerve endings in the brain would simply rush by and be erased within a few tenths of a second.

This is fortunate, since forgetting is a very useful tool when it comes to ordering our thoughts and filtering useless information. If our brain cells could retain every crap of conversation that we hear in the course of the day, we would soon so no longer know what was happening in our heads. So our memory is constantly busy selection and ordering information is to us at present or will be for the future. A lot depends on the emotions that we associate with the information, as well as the relationship it has to our personality and experiences. Some messages are only stored for about ten seconds- the time needed, for example, to remember a telephone number and dial it – and discarded immediately. We seldom succeed in recalling such fleeting information.


The Brain, Store house of Memory Part I

Memory is one of the vital building blocks of intelligence. Without memory there would be no learning, no recall no communication. Every second of the, day your memory is busy processing images from the world around you and storing them in the appropriate portion of your brain’s data banks. The way this process works is still only partially understood.

The capacity to remember is one of the miracles of the mind. We remember all kinds of things- telephone numbers, dates, prices, titles of books. Each person has his or her own capacity for memory, and some people can remember truly stupendous amount of information: Bhandata Vicisara, from Burma, can recite 16,000 pages of Buddhist scripture by heart; Hideaki Tomoyori from Japan, can reel off the first 40,000 decimals places of the value of Pi and French woman Dany Sirejean can name the day of the week for any random date of the 20th century.

But in spite of intense investigations into the workings of our memory, scientists are only slowly beginning to understand the functioning of the giant data bank in our brains. Hidden there is a complex archiving centre based on he co ordinations of billions of nerve cells. Our memory is so sensitive that some times just glancing at a rough outline or hearing a few words is enough to reconstruct an entire picture in our minds.


Friday, February 19, 2010

Little known facts about brain II

Despite growing knowledge about our body still do not under stand, how the brain assign different tasks to its two halves. Research has focused on linking specific areas of brain to certain function. But now the Broca’s method has been replaced by the study of living brain.

The PET technique involves the injection of harmless radio active glucose onto the blood stream. A brain area where the glucose is observed in greater amount indicates an increased activity.

The Doctors are now able to examine impaired brain functions in living patients for example a man who has vision in one eye, though both eyes were healthy can diagnosed with a localized affliction of the right half of the brain. It was also possible to identify the damaged brain area of a man who could not recognize the members of the family.

New technology allows scientists to identify the brain’s main sensory regions, the control area of our movements and other areas that are responsible for vision and speech. Research suggests that each activity correspond not just one zone but to a series of specialized zones, which came in to play when these activities performed.

It has been possible to identify the distinct vision zones that are independently analyze the form color and dimensions of an object and construct a coherent image of it. If any one of the decoding element malfunctions then our perception of an object will be faulty.

As our knowledge grows the mapping of brain is becoming more and more detailed. The fact remains though that each person’s brain is unique. Along side the differences between individuals, there are also differences of sex age etc.

Last but least, women make use of both halves of the brain more often than men, who tend to rely on the left half. Nevertheless, the more we discover about the brain the more we came to appreciate the miracle of human thought. The Planum temporale a small zone associated with language, which is found in both halves of the brain is more develop in the left side in 90% of right hander, but 70% of left hander have an equal development in both sides.

Little known facts about brain-I

In1861 the Doctor named Paul Broca in France conducted an autopsy of a body. There was some thing special about the man who died. That man was Leborgne lived in Paris, simply known as Tan Tan. As the two syllables tan tan were the words he could say, but he could understand exactly what was told to him. Apart from that he read newspapers, played chess etc as a normal man. So Borca wanted to find out whether Tan Tan really was insane.

Here I wish to tell few words about Dr. Paul Broca(1824-1880). He was the first to recognize that mental capacity is linked with specific areas of the brain.

In 1860, another case that was decisive importance in understanding human thought process was that of an epileptic person named Kevin. Doctors served his corpus callosum the slab of nerve fibers that connect the two halves of the brain. But instead of cure, new complication arouse, Kevin could only laugh when he was instructed to do so by speaking in his right ear. His left ear was functionally intact. Further more, he no longer recognized familiar faces when they appear in his right field of vision. This is an unfortunate personal impairment was a boon to the scientists. This impairment provided vital clues about how the two hemispheres of our brain interact to perform their tasks

Every muscle in left or right half of our body is controlled by nerve cells in the opposite half of your brain. The reason for this is that each part is responsible for specific task. The analysis of shapes in space, recognition of faces, the memory of sound and music awareness, are all assigned to the right hemisphere. The left is responsible for the task such as smiling, doing calculation and logical problem solving. This hemi sphere of the brain also governs the learning of language as well as written and spoken language.

Even though each half of the brain has its specific functions both halves work in co ordination to control the tiniest nuances of our behavior. The necessary connection is made through the corpus callosum, the slab of nerves discussed earlier. Why Kevin could not recognize a person sitting on his right is that the left half his brain which receives visual information could not communicate with the right half of the brain which is responsible for recognizing faces.

If one half of the brain is injured the opposite side can be replace it to a certain extent particularly in young people. Research indicates that there are large numbers of cerebral areas which do not have a specific functions are activated by nerve cells. It seems that non functional areas serve as reserve tissue.