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Memory and the brain
Sub-Topics

How Memory Works


Linked
Aide Link :  What Is Brain Plasticity? Link :  Plasticité du cerveau Link :  Evolution Channel : Neuronal Plasticity
Link :  The Brain that Changes Itself Experience : Tool-use induces morphological updating of the body schema   Link :  Translation of this page in Polish  -  Plastycznosc w sieciach neuronowych  

“I have it at the tip of my tongue!”

Oligomers Help Us Keep Our Memories

Glial Cells Too Are Sensitive to the Environment

The Collective Intelligence of Human Groups

The pathways along which information travels through the neurons (nerve cells) of the brain can be compared with the paths through a forest. As people keep taking the same route through a forest, they wear out a path in it. And the more people who take this path, the more deeply it is worn and the easier it becomes to follow. The same goes for our memories: the more we review them in our mind, the more deeply they are etched in our neural pathways.

The fundamental characteristic of the human brain that makes learning and memory possible is its plasticity: the ability of the neurons to modify their connections to make certain neural circuits more efficient.

Efficient at what task? Usually, at expressing a new behaviour that is better adapted to the demands of our environment, and hence more likely to preserve our living organism and improve its chances of survival.

PLASTICITY IN NEURAL NETWORKS

Every time you learn something, neural circuits are altered in your brain. These circuits are composed of a number of neurons (nerve cells) that communicate with one another through special junctions called synapses.

When you learn something, it is actually these synapses whose efficiency increases, thus facilitating the passage of nerve impulses along a particular circuit. For example, when you are exposed to a new word, you have to make new connections among certain neurons in your brain to deal with it: some neurons in your visual cortex to recognize the spelling, others in your auditory cortex to hear the pronunciation, and still others in the associative regions of the cortex to relate the word to your existing knowledge.

To learn this new word, you repeat it to yourself several times, and this selects and strengthens the connections among these various circuits in your cortex. And it is this new, durable association among certain neurons that will form your memory of this word. The strength of this association may of course depend on several factors.

To remember the word days or years later, you will have to successfully reactivate these same neural circuits. Obviously, this will be easier if, when you first learned the word, you built these circuits to last, by repeating the word and thus sending the corresponding nerve impulses down them many times. In contrast, if you repeated the word only a few times, then the connections among the new neurons would be weaker, and the new circuit would be harder to reactivate.

All your memories (of events, words, images, emotions, etc.) thus correspond to the particular activity of certain networks of neurons in your brain that have strengthened connections with one another.



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