Friday 20 November 2015

Neural Basis of Memory

The capability which sets humans apart from other animals is learning and memory. Learning is defined as a change in behavior as a result of experience, and memory is what has been learned. Language, knowledge, culture and attitude are all learned.
Iconic memory
All humans have virtually perfect graphical or photographic memory. When a visual scene and array of letters is shown to you for a moment, much accurate information about the scene is held in the memory. But this photographic memory lasts only for about one tenth of a second; most of its part is then forgotten. It is also called “iconic memory”. The word iconic is derived form the Greek word “icon” meaning “image”.
Short term memory
When you look up a new telephone number, you can remember it just long enough to dial, it will be forgotten if you do not repeat it to yourself. This is short term or immediate memory. Actually this is what your brain hold immediate awareness at a single moment. Short term memory is limited to almost 7 items held in memory for a moment. Your short term memory may be taxed beyond its limit if you have to remember some zip code or new telephone number.
Long term Memory
If you practice a new telephone number and repeat it again and again, by sometime you are able to remember it for a long period of time or sometimes you remember it permanently. This is long term memory. Some people has ability to remember telephone numbers immediately while some people always forget the numbers. This depends on person’s brain that of what things it has ability to remember for a long time.
Memory and Neurons
Neuron is the basic unit of brain; we can say that the core component of brain is neuron or nerve cell. Neuron plays a role of transmitter and transmits information to other parts via electrochemical signaling. A human’s brain has almost 100 billion neurons and each neuron is connected with 10,000other neurons and passes signals to each other via synaptic network. The specificity of neurons is that they never die and never be replaced by new ones. If some of them are lost due to some accident, they can never be replaced by new ones except some specific cases.

neural
Structure of a typical neuron (adapted from www.human-memory.com)

Human memory capacity is estimated to be varying widely from 1 to 1000 terabytes which is more than the storage in any library in the world. A human’s memory depends on the number of neurons present, more number of neurons, more strong memory.
Scientists observed that if they provide electric impulse to a pair to neurons, a long term transmission connection is established between them, and a long-term potentiation(LTP) is created whose effect can last for long time, this helps to make a memory. The part of the brain, hippocampus controls all the memory related processes.
A recent study in March 2015 depicts that memory does not live in neuron synapses (the part of junction of two neurons), scientists said that the memory may forms when there are some permanent changes in chemical and molecular level during the transmission of signals between the neurons. And another chance of making memory is the changes in genes present in the nucleus of the brains cells.
Brain is the main part of the body and its health is necessary for the overall health. People who don’t care about their food and living styles, and keep on using excessive fast food and unhygienic food, they gradually face a loss in their memory. So take care of your brain and eat healthy food.
References
http://www.scientificamerican.com/article/memories-may-not-live-in-neurons-synapses/
http://www.human-memory.net/brain_neurons.html
http://www.sciencemuseum.org.uk/
The brain; an introduction to neuroscience by Richard F Thompson

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