Friday, August 29, 2014

The properties of human brain and brain - based learning

The brain is an organ that receives, registers and processes information. It is the most delicate and the most complicated organ. The human brain is a watery gelatinous mass of nerve cells or neurons. Neurons are the basic building blocks of human brain. Neurons communicate with one another through synapses. Recent report indicates that an average human brain has about 23 billion neurons (Rabinowicz et al 2002). Each of the neuron has about 60,000 to 100,000 synaptic connections and has a total number of synaptic connections of about 1027 . The human brain is connected to 30,000 miles (50,000 kms) of nerves. The neurons are arranged end to end and the neurotransmitters transfer signals across the gaps (synapses) of 0.02 to 0.05 microns. The brain is a dense web of interconnecting synapses. Neurons communicate using electrical impulses. The neurons actually make up less than a tenth of the cells in the brain. The other 90-98% by number is glial cells, which are involved in development and maintenance.

Computational power of human brain

The estimated computational power of the human brain is about 1013 to 1016 operations per second. The speed of conduction of message is 200 miles per hour. The performance of a brain depends upon not on the number of neurons, but upon the information network (neural pathways) and the number of synapses. The neural pathways are both the network along which energy travels and the pattern through which information is processed in the brain. The number of synapses inside a human brain is directly related to intellectual and academic performance, activities that are centered in the human cerebrum.
The human being has the highest ratio of weight of the brain to the total body weight. The human brain weighs about 1.5 kgs, about 2 percent of body weight. The brain requires 15 percent of the blood, 40- 50 percent of the oxygen supply and 25 percent of the calories we consume. A 15 sec blockage of blood to the brain will result in unconsciousness. The brain cells are sensitive to oxygen availability. The brain cells have the ability of dividing and giving rise to new healthy cells, most particularly in the hippocampus, the area most crucial to learning and memory.
              “The human brain, then is the most complicated organization 
                  of matter that we know”--Isaac       Asimov.

Growth stages of human brain 

First increase occurs at the age of two, when a child starts to walk and begin to talk.
The second increase occurs at the age of six, when the child begins to learn to read and do math. The third increase occurs at the age of twelve, when he or she begins to grasp abstract and logical concepts. The various regions of the brain develop at different rates in different people. No two people’s brain stores the same information in the same way in the same place. Biologically the brain processes 400 billion bits of information per second, but is only aware of 2000 bits any one time.

Functional properties of human brain 

The brain expands with use – the more the brain is used, the more memory associations are formed. No new nerve cells develop in the brain after birth but new synapses do seem to grow and develop. New neural circuits and networks form between the neurons.
The brain loves to explore and make sense of the world – human brain is endlessly seeking to make sense of what it experiences. The brain seeks to establish new networks to process and store knowledge. The brain’s design strikes a balance between circuit performance and circuit plasticity. More plasticity exists in cortical circuits, where new dendrites can grow and synaptic connections can be made throughout life.
The brain is a pattern detector – the brain makes sense of the world by constructing or mapping patterns of the world. Nature exists as patterns. The recognition function of the brain involves ‘pattern matching’.
The brain is ‘born’ prematurely – much of its development occurs after birth and for many years afterwards. Experience can shape the brain. Neuroplasticity is the ability of the brain to change as a result of experience. A creative brain is flexible and imaginative.
Every brain is wired differently – the rate of neural growth seems to match the intensity of real-world learning. Learning results in growing new neural networks i.e. new knowledge structures. Learners of the same age show a great deal of intellectual variability.
The brain’s ability of attention – the brain naturally focuses on concepts sequentially, one at a time. The brain operates on alternating cycles of high attention and periods of inattention. During the period of inattention, the brain engages in the process of questioning, revising, one’s understanding etc. in order to comprehend i.e. ‘concept consolidation’.
Exercise boosts brain power – Exercise stimulates one of the brain’s most powerful growth factor, brain-derived neurotrophic factor(BDNF), which aids in the development of new cells in the brain. Exercise increases blood flow to the brain and the blood brings glucose, oxygen and proteins. Proteins encourage neurogenesis
The brain does not act as a computer in a linear fashion- The brain uses multiple strategies to create meaning. The brain is incapable of multitasking.
The brain does not perform well under too much stress – stressed brain doesn’t learn at all. Stress hormones interfere with the hippocampus’s ability to grow new neurons. Stress causes brain damage.
Every brain simultaneously perceives and creates parts and wholes- The brain is a parallel processor. Thoughts, emotions and imagination operate simultaneously. The brain understands and remembers best when facts are embedded in natural spatial memory.
The brain is a social organ- it develops better in concert with other brains.
                                         The more you use,
                                         The more you get.

Functional units of human learning

The human brain is composed of thousands of functional modules i.e., mini-brains within a brain. It is through multiple, complex combinations of these functional modules, through a myriad of interconnections that our brains create functional neural systems.  The functional unit of the mental activity is not the single neuron but a circuit of interconnecting neurons all activated at the same time (neural networks). Environmental stimulation can increase the numbers of neural connections and the strength of connections. Learning is a process that establishes new connections among networks and the new skills or knowledge that learned is neural circuits and networks. The brain is continually resculpting itself in response to experience and learning.

Brain plasticity and learning

Marvin Minsky (1986) in his book ‘The Society of Mind’ quoted as ‘The principal activities of brains are making changes in themselves.’ The brain’s ability to change with experience is called plasticity. The brain is a pliable organ like plastic, hence the term brain plasticity. The plasticity does not mean large-scale physical rearrangement of regions of brain tissue. The changes occur only in the internal structure (microstructure) of the brain, not its overall shape. The education is functional plasticity i.e., the ability to change behaviour following external or internal experiences. The functional plasticity refers to the growing, dropping and strengthening of neural networks.

Brain – based learning, BBL

The brain is extremely complex, dynamic and adaptive (plasticity) system. The brain consists of hundreds of billions of neurons and inter-neurons that produce an enormous number neural nets or groups of neurons working together, from which our daily experience is created. The brain’s activity is controlled by genetics, development, experience, culture, environment and emotions.
According to Eric Jensen (2000) brain – based learning is “learning in accordance with the way the brain is naturally designed to learn.” According to Fishback (1999), “the creation of neural networks and synapses are what constitutes learning.”
There are billions of neurons and the number of synapses is more than 10,000 times the number of neurons (Hill, 2001). ‘A single neuron can have from a few thousand up to one hundred thousand synapses and each synapse can receive information from thousands of other neurons(“The neurons that fire together wire together”). The resulting 100 trillion synapses make possible the complex cognition of human learners.’

Neural changes during learning

The physical brain is literally shaped by experience; axonal circuits change, modify and redevelop as human’s age. The human brain actually maintains an amazing plasticity throughout life. This means that any learner can increase their intelligence, without limits, using proper enrichment (Jensen 2000).
Neuronal growth is initiated by learning followed by assimilation and accommodation. In assimilation, the incoming information is changed to fit in to existing knowledge structures. Accommodation occurs when an existing cognitive structure (i.e., current neuronal circuits) is changed to incorporate new information (Ally 2004). The human brain is always looking to associations between incoming information and experience. The greater the amount of information and experience, the brain extracts and ‘compartmentalizes’ (lateralizes) the information (Jensen 2000). Thereafter the brain creates patterns of meaning. The pattern making depends on past information or experience. According to Jensen (2000), ‘Learning is best when focused, diffused, and then focused again.’ Jensen (2000) explained that proper environment is important for learning to occur. Color, hydration, visual stimuli, psychological stimuli, seasons, temperatures, plants, music, noise and aromas can all influence learning. Learning engages the entire physiology, physical development (stress, diet, exercise ), personal comfort and emotional state will affect the brain. All learning involves our body, emotions, attitudes and physical well being.

Educational neuroscience

Education is about enhancing learning and neuroscience is about understanding the mental processes involved in learning (Report by the Royal Society, UK, 2011). The goal of educational neuroscience is to work out how all learners can be helped to achieve their learning potentials and to make learning more effective for all learners. Neuroscientists investigate the processes by which the brain learns and remembers from molecular and cellular processes right through to how brain systems function.
                             To make life and success easier,
                                Take better care of your brain.

“Brain is an apparatus with which we think that we think”.
                         –Ambrose Bierce, 1911.
“The human brain functions as a high speed internet system. 
 The quality of the brain’s connections is the key to its speed,
 bandwidth, fidelity and overall on-line capacity” (Dr.George Bartzokis).

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