HUMAN BRAIN

LARGEST AMONG ANIMALS

• The human brain has the same general structure as the brains of other mammals, but is larger than any other in relation to body size.

• Large animals such as whales and elephants have larger brains in absolute terms, but when measured using the encephalization quotient which compensates for body size, the human brain is almost twice as large as the brain of the bottlenose dolphin, and three times as large as the brain of a chimpanzee

• Much of the expansion comes from the part of the brain called the cerebral cortex, especially the frontal lobes, which are associated with executive functions such as self-control, planning, reasoning, and abstract thought. The portion of the cerebral cortex devoted to vision is also greatly enlarged in humans.

Difference between MEN &WOMEN BRAIN

• The adult human brain weighs on average about 3 lbs. (1.5 kg) with a volume of around 1130 cubic centimetres (cm3) in women and 1260 cm3 in men, although there is substantial individual variation. Men with the same body height and body surface area as women have on average 100 grams heavier brains, although these differences do not correlate in any simple way with IQ or other measures of cognitive performance.

LANGUAGES• In human beings, it is the left hemisphere that

usually contains the specialized language areas. While this holds true for 97% of right-handed people, about 19% of left-handed people have their language areas in the right hemisphere and as many as 68% of them have some language abilities in both the left and the right hemisphere.

RECOVERY IN CHILD

• Studies of children have shown that if a child has damage to the left hemisphere, the child may develop language in the right hemisphere instead, an example of plasticity of the brain, allowing other regions of the brain to adopt the function of a damaged area. The younger the child, the better the recovery. So, although the "natural" tendency is for language to develop on the left, human brains are capable of adapting to

METABOLISM OF BRAIN

• The brain consumes up to twenty percent of the energy used by the human body, more than any other organ.[37] Brain metabolism normally relies primarily upon blood glucose as an energy source, but during times of low glucose (such as fasting), the brain will primarily use ketone bodies for fuel with a smaller requirement for glucose. The brain can also utilize lactate during exercise.

• Although the human brain represents only 2% of the body weight, it receives 15% of the cardiac output, 20% of total body oxygen consumption, and 25% of total body glucose utilization.

• he energy consumption of the brain does not vary greatly over time, but active regions of the cortex consume somewhat more energy than inactive regions

MEMORY• Long-term memory (LTM)• Short-term memory(STM)• Intermediate-term memory• According to the theory, long-term memory differs

structurally and functionally from sensory memory, working memory, short-term memory, and intermediate-term memory. While short-term and working memories persist for only about 20 to 30 seconds, information can remain in intermediate-term memory for 5 to 8 hours, and in long-term memory indefinitely

EFFECT OF SLEEP• one group was given the information at 9am and

the other group received theirs at 9pm. Participants were then tested on the word pairs at one of three intervals 30 minutes, 12 hours, or 24 hours later. It was found that participants who had a period of sleep between the learning and testing sessions did better on the memory tests. This information is similar to other results found by previous experiments by Jenkins and Dallenbach (1924).

DREAMS

• Dreams are successions of images, ideas, emotions, and sensations that occur involuntarily in the mind during certain stages of sleep. The content and purpose of dreams are not definitively understood, though they have been a topic of scientific speculation and a subject of philosophical and religious interest throughout recorded history. The scientific study of dreams is called oneirology. Scientists believe that other mammals, birds and reptiles, also dream.

• Dreams mainly occur in the rapid-eye movement (REM) stage of sleep—when brain activity is high and resembles that of being awake. REM sleep is revealed by continuous movements of the eyes during sleep. At times, dreams may occur during other stages of sleep. However, these dreams tend to be much less vivid or memorable.

• Dreams can last for a few seconds, or as long as twenty minutes. People are more likely to remember the dream if they are awakened during the REM phase. The average person has three to five dreams per night, but some may have up to seven dreams in one night.

BRAIN ACTIVITY DURING DREAM

HOW TO HACK HUMAN BRAINS

• Emotiv brain-computer interface (BCI) for the gaming and entertainment industry. The device was designed to let users play computer games or to control their computers by their thoughts alone. But now researchers show that this device can also be used for a malicious purpose: to hack into a person’s mind and extract information such as computer passwords and banking data.

• Researchers at the University of California and the University of Oxford in Geneva tested the security risks of BCIs. They found that a person can easily reveal private information via a brain wave pattern known as the P300 response, which is present when a person’s brain registers stimuli as meaningful.