Memory and its disorders

Memory is the organism's ability to receive, store and recall previous experiences.

• It enables the preservation of past experience, it is a necessary condition for adaptation.
• Memory is one of the functional systems of the brain (such as emotions, motor skills, …).
• There are two main types of memory – phylogenetic and ontogenetic.

Phylogenetic Memory

• Unconditioned reflexes
• Instincts

Ontogenetic memory

• Ontogenetic memory can be divided in different ways:

1. declarative memory – conscious, explicit, verbal (statements), non-verbal (ideas);
   1. semantic component – ​​information obtained through certain specific experiences;
   2. episodic component – ​​contextual, memories of events.
2. non- declarative memory – procedural memory – implicit, not clearly aware, developmentally old memory, memory contents contained in various skills.

• Clinical division:

1. immediate – within 30 s;
2. recent – ​​several months;

• for remote events.

• Division according to the retention time of the memory trace:

1. short term;
2. long term.

• Division according to experimental physiology:

1. working memory – processes in the short term;
2. operational memory;
3. stock.

Basic memory skills:

Ontogenetic memory

• Ability to store (implantability, impregnation).
• Ability to keep, fix (retention).
• The ability not to change, to have stored without changes (conservation)
• Ability to recall (reproduction).

Ultra short memory

• The sensory register, lasting fractions of seconds to a second, is closely related to attention.

Short-term memory

• It is based on reverberation circuits (short-term temporary connection of neural networks along which the excitation circulates).
• It lasts on the order of seconds, in the event of a malfunction, the ability to absorb is damaged (disorder of the reticular formation, frontal lobes).

Consolidation phase of memory - medium-term memory

Location of the hypothalamus

• Some circuits disappear in the short term, others persist, the emotional component, and the principle of reward and punishment is important.
• The limbic system and thehypothalamus, are mainly involved in emotional remembering.
• The consolidation phase is the transition to long-term memory, it includes the creation of memory traces.
• The limbic system is activated by reward and punishment, it strengthens the influence of appropriate stimuli.
• Electrochemical changes occur - pharmacologically influenceable.
• Acetylcholine is of great importance for this kind of memory.

Long-term memory

• Long-term memory has a structural, morphological basis, the number of dendrites increases; in old age, due to toxins, their number decreases, during intensive learning, the number of dendrites increases; this process appears to underlie memory.
• The mechanism of activation of spines in the hippocampus – AP activates the enzyme calpain I, thereby creating the substance fodrin, which is contained in the neuronal cytoskeleton, degrades and exposes excitatory AMK receptors.
• The issue of localization is highly controversial.
• A prerequisite for conscious memorization is a motive.
• Determinants – the strength of the stimulus, emotional coloring, ability to concentrate, and emotional tuning.
• Everyone has different dispositions, someone has a better visual, ...
• Memory is impaired by fatigue and passivity.

Memory failures

Hypomnesia

• Decreased memory performance, either globally or selectively.
• Most often with organic impairment, as part of the dementia syndrome.
• When tired, due to drugs, toxins.
• In dementia, inculpability is mainly impaired.
• Confabulation – the affected person answers the questions closely but factually incorrectly, but he is nevertheless convinced that he is right, and in a moment he can answer the same question differently.
• Amnestic disorientation – a total implantable disorder.

Korczak syndrome

• Impulsivity disorder, confabulation , amnestic disorientation.
• Alcohol dementia, Alzheimer's disease.

Amnesia

• Complete memory loss, usually limited in time, full or selective.
• Retrograde, anterograde.
• Common in quantitative disorders of consciousness, after injury.
• Continuous or island-like (delirium, alcohol intoxication - e.g. window -palimpsest).
• Selective amnesia – in hysterical persons, it displaces unpleasant memories.

Transient global amnesia

• Amnestic stroke: a sudden memory disorder, mainly organic, caused by a strong stressor, starts suddenly, ends suddenly.
• Psychogenic amnesia
• Dissociative amnesia: dissociative fugues (wandering), influenced by hypnosis.

Hypermnesia

• Excessive, disproportionate memorization of certain selective material.
• Usually part of paranoid psychoses (remembers associations related to delusion).
• In neuroses, mania.

Paramnesia

• Distortion of the stored content, but the person has a sense of accuracy.

Memory Delusion

• In pathic paramnesia, the bearer is irresistibly convinced of the reality of a certain idea, typical ofpsychosis and personality disorders.

Ecmnesis

• Inaccurate temporal localization of the correct memory

Cryptomnesia

• In unintentional plagiarism, the patient is convinced of the authorship of something that he did not invent himself, but read or heard somewhere.

Pseudologia phantastica

• "Baron Prasil's Syndrome“, is a fabulous lie - it is not a true memory disorder, typical of hysteria, even in children.

Attention (prosexy)

Reticular Formation

• Attention is a mental function, it can be described as focused perception.
• It is the ability to purposefully select certain perceptions from a complex of perceived stimuli.

Characteristics of attention:

1. concentration – the intensity of focus;
2. capacity – an indicator of the extent of attention, the number of perceptions that we can simultaneously monitor;
3. tenacity - constancy, perseverance;
4. irritability – threshold of intensity of stimuli capable of binding attention;
5. vigilance - the ability to distribute it.

Dividing attention

1. active;
2. passive (unintentional).

• A certain level of alertness (ARAS) and sufficient motivation are needed to maintain attention.

Hypoprosexia

• Decreased attention span.
• General or selective.
• Overall, mainly in dementia, and severe depression.
• Oligophrenia, including neuroses, pharmaceuticals (barbiturates, neuroleptics).

Hyperprosexy

• More often selective.
• Manic syndrome – increased irritability, tenacity, and distribution, but attention tends to be unstable and oscillates.

Paraprosexy

• The incorrect focus of attention.
• For example,schizophrenia – excessive focus on delusions.

Links

Related Articles

• Amnestic syndrome

Source

• BENEŠ, Jiří. Study Material [online]. [cit. 2009]. <http://jirben.wz.cz>.