Long Term Memory

Long term memory consists of anything you remember that happened more than a few minutes ago. Long term memories can last for days or even years. The capacity of long term memory can be unlimited. It is a system of permanently storing, managing and retrieving information, which can be used later.

Types of long-term memory

>Explicit memory (declarative memory)
>Implicit memory (non-declarative memory)

Explicit memory: it is also known as declarative memory. Declarative memory is the memory of events, factual information, data, and general knowledge. We are consciously aware of our explicit memories and we can verbally declare them. We can communicate such memories to ourselves and others by speaking. Ability to understand the concept of math, remembering what you did yesterday, and recall the events are examples of declarative memory. These memories are encoded by the entorhinal cortex, hippocampus and perirhinal cortex, but stored in temporal cortex. Amnesic patients with damaged temporal lobe perform more poorly on explicit learning tests as compared to healthy people. This shows that the temporal lobe is involved in explicit learning.

Explicit memory is sub-divided into:
• Semantic memory
• Episodic memory

Semantic memory contains general factual information, such as the meaning of words and knowledge related to our world. Semantic memory does not depend on context memory; so, older adults and younger adults do not show much difference in semantic memory. It includes:
• The concept of a book
• Understanding of multiplication
• Your knowledge of the Civil War
• The meaning of the word ‘memory’

Episodic memory consists of our memories of personal past experiences that occurred at a particular time and place. Episodic memory consists of personal facts and experiences. Episodic memory requires context dependent memory, so older adults have worse episodic memories than younger adults. This includes:
• Memories of your first kiss
• Remembering what happened at the last basketball game you attended
• Remembering the last meal you ate
• Remembering the first time you met your husband
• Remembering someone’s name

We use episodic memory, when we recall specific experiences or events that we have had in our lives.

Implicit memory (procedural memory): It is the memory of performance of particular types of action, (motor skills). This memory stores information about how to perform certain procedures; such as, talking, walking and riding a bicycle. Implicit memory is considered as unconscious or non-declarative memory. This type of memory is encoded and stored by striatum and other parts of the basal ganglia.