Memory

Original Editor - Cindy John- Chu Top Contributors - Cindy John-Chu, Lucinda hampton, Nikhil Benhur Abburi, Tolulope Adeniji, Vidya Acharya, Naomi O'Reilly and Kim Jackson

Introduction

Memory is defined simply as the capacity to store and retrieve information. It is a sum of the processes that entail acquiring, storing, retaining and eventually retrieving information. Contrary to popular belief, memory does not deteriorate with age. Memories are stored through the strengthening of synaptic connections between nerve cells.

Types of Memory

Three main categories of memory have been identified namely as:

• Sensory
• Short-term and
• Long-term memory

Sensory Memory

This form of memory involves an entirely unconscious effort to occur. Sensory memory (SM) is the shortest form of memory. It involves the capacity to store impressions after having ended the original stimulus. It is responsible for receiving stimulus from the five senses which are stored briefly but accurately. Storage of this kind of memory is done automatically and is unable to be elongated through rehearsal. SM translates into short term memory through the process of attention, which involves selectively concentrating on one aspect of the environment while ignoring other elements.

Short-Term Memory

Short-term memory (STM) may be defined as the maintenance of information over a brief period which often occurs in seconds and results from conscious maintenance of sensory stimuli within this time frame. It is also known as primary or working memory. It involves remembering and processing information at the same time. Only a small amount of information is stored for a short time ranging from 15 seconds to 1 minute. STM becomes long-term memory when information is consciously stored through a process known as consolidation. This process is enhanced through repetition, associating new information with previous knowledge and/or a subject of keen interest. The prefrontal cortex is the primary area of the brain responsible for STM.

Long-Term Memory

Long-term memory (LTM) is the final stage involved in processing memory and is largely a store of previous events. It refers to memories that have become stable and unyielding to interference. It is otherwise referred to as secondary memory. Recall from LTM is usually done with ease when compared to that from STM. Information stored in LTM can last between months to decades.

There are basically two types of LTM namely: explicit and implicit memory.

Explicit Memory: Also known as declarative memory, explicit memory refers to memories that are consciously brought to the fore. It is further divided into: episodic memory and semantic memory.

• Episodic Memory refers to memories that require knowledge of the details of events as well as the time and place they took place. An example of this type of memory will be the first time venturing at a quest.

• Semantic Memory deals with the storage of factual information such as the meaning of words.

Implicit Memory: Otherwise known as non-declarative or procedural memory is the memory that relates with bodily movements in carrying out activities such as writing, driving and swimming. Four types of this memory exist. They are as follows:

• Procedural Memory is memory concerned with knowing how to do things. It is automatic and simply a memory of motor skills.
• Associative Memory as the name implies refers to memories that are stored and retrieved by association.
• Non-Associative Memory is associated with learning of new behaviours through repeated exposure to a single type of stimuli.
• Priming is the effect a previous memory or experience has on new information.

How to Improve Memory

A few ways which may help memory include, a healthy diet, exercise, not smoking and keeping blood sugar, cholesterol and pressure in check and an active lifestyle

Disorders of Memory

Include:

• Dementias
• Amnesias