What is memory?
Memory can be thought of as either a process or a structure that helps people store information and retrieve it later. Memory is divided into several different categories based on the amount of time it takes to retrieve memory content.
Ultra-short-term memory
Newly arriving information quickly displaces the current content in the immediacy memory. Only a small amount of information is transferred from sensory memory to short-term memory.
Short-term memory
Short-term memory allows data to be stored over a period of a few seconds to a few minutes. For example, you can briefly remember a number you looked up until you wrote it down.
Long-term memory
Long-term memory is where all important information that is worth keeping and that would otherwise cause short-term memory to “overflow” goes. This form of memory is generally meant when we speak of memory.
Declarative and non-declarative memory
Long-term memory is divided into declarative and non-declarative memory:
Declarative memory (explicit memory) is the term used by physicians to describe that part that stores explicit, i.e., conscious, linguistically retrievable, content. It is further subdivided into:
- episodic memory (autobiographical knowledge, i.e. knowledge about one’s own person and experiences)
The non-declarative memory (also called implicit memory) stores implicit contents. These are not directly accessible to consciousness and therefore cannot be retrieved linguistically. They include, for example, highly automated skills such as driving a car, riding a bike, skiing, or tying shoelaces (procedural memory).
How does memory work?
There is no clearly delineated structure in the brain for memory. Rather, a network of nerve cells that extend across different areas of the brain is responsible for the ability to remember and recall. In memory processes, therefore, different areas of the brain are active at the same time.
Brain areas responsible for memory processes
Frontal and temporal regions of the right hemisphere are responsible for processing episodic memory, while the same regions of the left hemisphere are responsible for processing content in semantic memory. To a strengthening or weakening degree, the cerebellum is also involved.
In order to retrieve memory contents, the functioning of the corpora mammillaria (belong to the diencephalon) is important.
What problems can cause memory?
In memory disorders, the ability to remember or recall is impaired. The trigger can be for example a trauma, for example an accident.
When short-term memory fails, those affected cannot remember directly preceding conversations or events, while older events, some of which occurred years ago, are remembered accurately. Short-term memory decreases increasingly with age. Those affected then prefer to concentrate on events that occurred long ago.
In the case of damage to the amygdala, memory content associated with emotions is disturbed. Those affected can only remember pure facts without any emotional content.
