Body processes

Long-Term Memory – Function, Task & Diseases

Long-Term Memory

Long-term memory is a neuronal, multimodal function that processes information and stores it over the long term.

What is long term memory?

Long-term memory can be divided into declarative and non-declarative memory . Declarative memory contains concrete knowledge, while non-declarative memory stores information that can be traced back to experiences.

Declarative content is stored in those cortex regions that were also involved in processing. Quite heterogeneous memory performance is assigned to non-declarative long-term memory. These include, for example, associative and non-associative learning, priming and habits and skills.

Non-declarative memory is related to the cerebellum , amygdala and striatum , among others, and is not dependent on conscious memory, whereas declarative knowledge can be consciously remembered and can therefore be used flexibly. Endel Tulving (*1972) also calls these two forms semantic and episodic long-term memory.

The episodic memory includes concrete events of a person, whereby spatio-temporal characteristics are also stored. This memory is also known as so-called source memory. Word meanings, facts and rule systems are contained in the semantic long-term memory. With episodic remembering, a single event can be recalled, which is not possible with semantic remembering.

Another form is procedural memory, also known as behavioral memory. It stores automated skills like driving or walking. These actions are learned through constant practice and can then be recalled without thinking.

function & task

In the brain , the information is not stored in a specific place, but can be found in the overall structure of the nerve cells and in their connections. The limbic system , the frontal and temporal lobes as well as the hippocampus , which transfers contents from short -term to long-term memory, are all involved. 

If content reaches the long-term memory, it is stored here permanently. For this purpose, so-called engrams are formed (memory traces as structural changes in the brain due to the effects of stimuli), which make remembering possible. Examples of long-term memory skills are remembering a poem, an uncomfortable situation, or the face of an acquaintance. Information is actively encoded, processed, stored and then reproduced or remembered.

An essential function of the long-term memory is therefore the provision of information in order to be able to make optimal decisions afterwards. Overall, there are four processes of long-term memory: learning, retaining, remembering and forgetting.

Long-term memory has an almost unlimited capacity. Learning takes place between the motor and sensory neuron ( nerve cell ). When the sensory neuron is stimulated, increased neurotransmitter release occurs and muscle activation occurs. The learning process takes place first as short-term storage and later as long-term storage, with the synapse enlarging and changing its function.

By relating the learning material to what is already known, information can be stored in long-term memory. Only extremely rarely, however, are certain facts or events faithfully reproduced. Previous knowledge seems to play an important role in remembering, but thinking or certain retrieval processes can also modify or distort content.

Diseases & Ailments

One possible condition related to long-term memory is memory problems . Disorders of memory, lack of concentration and forgetfulness are often due to exhaustion or stress if they do not occur more frequently . However, if the problems increase and normal daily routines become problematic, a doctor should be consulted, as forgetfulness can also hide a more serious illness. 

One possible disease is dementia , which impairs the ability to think or mental performance. Those affected have problems absorbing new content and then playing it back. Speaking , arithmetic and orientation are also affected.

The most common form is Alzheimer’s disease, in which brain cells die due to clumps of protein that appear outside or inside the nerve cells. Another common form is vascular dementia , which results from impaired blood flow in the brain. The so-called Lewy body dementia is less common .

Lewy bodies are spherical structures found in the cerebral cortex or brainstem . Those affected experience progressive memory impairment and suffer from movement disorders and psychotic symptoms.

Dementia can also occur with Pick’s disease . Above all, the ability to think abstractly is disturbed here and certain brain regions slowly die off. On the other hand, dementia in Creutzfeldt-Jakob disease develops very quickly . Disorders of concentration , attention or memory are the main causes, the causes being toxic proteins which cause the brain tissue to die off. Accompanying dementia is also possible with Parkinson’s or HIV . Other disorders that can lead to forgetfulness include:

  • Meningitis : Viruses or bacteria can cause confusion, drowsiness or poor concentration .
  • Inflammation of the meninges : Symptoms such as confusion or disturbances of consciousness occur here.
  • Sleep apnea : Since the night sleep gets out of rhythm with this disease, poor concentration, forgetfulness and tiredness occur during the day .
  • Chronic Fatigue Syndrome: Typical of this is physical and mental exhaustion, which is accompanied by irritability and poor concentration.
  • Depression and anxiety disorders can also affect the brain and lead to forgetfulness.

Other causes can be medication, lack of fluids and food , sleep disorders , stress, alcohol abuse and cancer therapies.

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Hello! I am Lisa Newlon, and I am a medical writer and researcher with over 10 years of experience in the healthcare industry. I have a Master’s degree in Medicine, and my deep understanding of medical terminology, practices, and procedures has made me a trusted source of information in the medical world.