Did you know that every time you learn something or acquire a new experience your brain's cells suffer a modification, and that modification will be reflected in your behavior?

For example, if you have ever walked through a street during the night and perceived that there were people looking like criminals, you would have avoided going through that street again. Or, a child who gets an electrical shock after inserting his or her finger in an outlet, will never repeat that behavior again. In these examples, the behavior was modified as a result of an experience.

Each neuron contributes to behavior and to each mental activity, producing or not electrical impulses. All memory processes are explained in terms of these electrical discharges.

The cellular alterations resulting from learning and memory are called plasticity. They refer to an alteration in the efficiency of the synapses that can increase the transmission of nervous impulses, thus modulating behavior..

The neuron

An experience can happen through an active learning, or by living in an rich environment that includes other individuals, colors, music, sounds, books, smells, etc.

It was also possible to demonstrate in scientific laboratories that a rat's brain presents a much greater number of brain cells interconnected to each other when they live together in a cage filled with toys as wheels, balls, etc., than rats living in a cage alone and without anything to do or learn.

Donald Hebb, from Montreal, and Jersey Konorski, from Poland, some of the major experts on the phenomenon of learning and memory in the 40's, were the first ones to believe memory should involve changes or increases of nervous circuits.

Nervous circuits are sets of brain cells (or neurons) that communicate to each other through junctions called synapse.

When a cell is activated, it is triggered the liberation of chemical substances in the synapses, called neurotransmitters, becoming them more effective. Research has found that neurons that are more "exercised" bear a greater number of ramifications dendrites communicating with the dendrites of other neurons. Thus, for memory to be established, it is necessary that nervous cells form new interconnections and produce new protein molecules.


Synaptic transmission

Silvia Helena Cardoso is a psycobiologist, doctor of Sciences by the State University of São Paulo, Brazil, post doctoral by the University of California, Los Angeles, associate researcher at State University of Campinas, managing and editor-in-chief of the Brain & Mind magazine.

Contd. Human Memory: What it is and How to Improve It
By: Silvia Helena Cardoso, PhD
In: Brain & MInd