Chapters 6- Cognition 02. Memory and learning

02. Memory and learning

yellow-warning1Article automatically translated : We'll be reviewing and optimising it soon ...

Memory plays a crucial role in our lives [ 3 ]. In fact, without memory there would be no meaning to life. Memory is the way to be in time, this is the fabric that shapes the history of each.

1. Definitions:

Memory is defined as the ability to capture, encode, store and reproduce a particular power [information 4 ].

We often confuse memory with learning. Although these two processes are often linked, it is worth mentioning that learning [ 1 ] applies primarily to the phase of acquisition and storage of memories.

The recall involves active retrieval of information, whereas recognition requires only decide whether a thing among others has been previously encountered [ 119 ].

2. Classifications:

The notion of memory, very common usage is actually more complex than it has in the air. Indeed, there are several types of memory [ 38 , 135 ]:

2.1. Versus time.

2.1.1. Sensory memory [ 145 ]:

This is extremely short duration, that is none other than our perception of things and events. It is the echo and resonance internal sensory information that persist within fractions of seconds in our conscious.

2.1.2. The short-term memory [ 161 ]:

Also known as (working memory [ 163 ]), is a level of selective filtering of information gathered by our senses for at least one minute [ 164 ]. It allows us to retain some elements, an average of 7 data: a phone number, for example [ 42 ], data with which we work (hence its name). Them according to their importance may or may not move to another level of long-term storage.

2.1.3. The long-term memory [ 165 ]:

The long-term memory provides backup memories for a long time, months, years or even a lifetime.

2.2. Depending on the information to be stored:

Depending on the type of data to be stored [ 39 ], it may be a:

2.2.1. Explicit memory [ 165 ]:

also called declarative [ 167 ], for data that can be expressed in words. We distinguish:

  • Semantic memory [ 164 ] Regarding the storage of objects and specific things.
  • Episodic memory [ 145 ] regarding events well located in time.

2.2.2. Implicit memory [ 166 ]:

Also called procedural [ 165 ], is essentially a motor memory regarding expertise. Automation is made so well integrated that we do not have awareness sensorimotor. For example, someone who knows how to make sutures, it will be difficult to explain the method using only words.

Many of our emotional conditioning and our conditioned reflexes are also part of implicit memory.

3. The memory efficiency:

3.1. Nature of memory:

Our memory is associative [ 119 ], that means it is more effective if the data is associated with storing items already stored in our memory, one thing reminds us of another, which reminds us of another etc..

Memory is the result of a reconstruction of different elements. It does not save entire scenes in our brain. Moreover, no memory is really identical to its origin as a picture, it would make a lot of things to remember and our skull and unfortunately inextensible.

We retain only a few pieces of the puzzle, some bread crumbs that will help us to rebuild and recover after souvenirs from various key elements.

3.2. Factors influencing the memory:

Several factors influence the effectiveness of memory [ 168 ]:

  • The degree of vigilance, alertness, attention and concentration during storage.
  • The interest, motivation, need or necessity of things to remember.
  • Repetition.
  • Location, lighting, odor, noise ... short, while the present context when storing registers with the data store.
  • The effort of memory, hence the term (working memory). Working memory is to give meaning to the items to be remembered and make logical connections with what we have already achieved. More a memory is encoded, developed, organized and structured, it will be easy to find.

4. Mechanisms of memory:

Several neural structures play a crucial role in memory:

The hippocampus [ 54 ] plays a key role in episodic memory. It allows you to constantly collect data from different sensory areas (visual, auditory, somatosensory ...), select the most important, link in one episode of events instead of being a collection of separate memories and redistribute to appropriate areas.

People who underwent removal of both hippocampi can not register new memories in their long-term memory [ 167 ], but they retain their ability to recall old memories before surgery.

Some very intense personal memories involve what is called emotional memory [ 169 ]. This would involve more hippocampal another structure of the limbic system: the amygdala [ 39 ], a region known for managing our fear reactions. Several other structures of the limbic system contributes to encode our memories permanently.

The tracking information to long-term memory following the Papez circuit [ 38 , 50 ], it binds hippocampus, fornix, mammillary bodies, anterior thalamus and cingulate gyrus.

Procedural memory would not seek the entire hippocampus. It is rather associated with changes in the cerebellum [ 1 ], the basal ganglia and motor cortex.

The prefrontal cortex plays an important role in working memory [ 1 ].

No single neuron itself contains the information necessary for the return of a memory. The brain retains data through the formation of new networks. These networks can be modified through the formation of new synapses or strengthening others. These may well have existed before, but functioning would have been ineffective.

The long-term potentiation (LTP) [ 3 , 38 , 39 ], which is the main mechanism of neurological plasticity plays a key role in the formation and effectiveness of these synapses.

Chapters 6- Cognition 02. Memory and learning