The human memory is the most puzzling subject and many scientists have conducted numerous studies on memory and its functioning. It makes us who we are and is central to the daily functioning of our life.
Simply put, memory encompasses the encoding or perception of information, storage of information and the retrieval of the same as and when needed. It can be thought of as large storage device that lets you store important data and retrieve the same when performing a specific task.
The memory is not stored in a single place inside the brain but stored in different areas of the brain. It involves a distributed processing where different areas of the memory work together to perform a simple task.
So, even if one part of the brain gets damaged, it does not handicap you totally and still lets you perform certain functions. Typically, memory entails the following process:
- Encoding – Registration of an event – Processing and combining different data
- Storage – Creation of records in the short term and long term memory stores
- Retrieval – Recalling the stored information to generate response for an event
Types of Memory
All the outlined types of memory below work in tandem with each other in order to perform a necessary action.
- Sensory Memory – It is the shortest memory withholding information for a few seconds. It is an automatic response to looking at something and immediately identifying it using our memory. The stimulus that is generated by our senses of seeing, hearing or touching are either ignored or noticed which then come into our sensory memory. It does not involve any storage of information as such and is a fast decaying store. Sensory memory is further narrowed down to three levels
- Iconic Memory – Stores visual information through the sense of seeing
- Echoic Memory – Stores audio information through hearing a particular sound
- Haptic Memory – It stores information associated with the touch stimuli
- Short–Term Memory – It is popularly known as the working memory that clenches information within seconds to minutes for later recovery. It is like a notepad that holds temporary data that can be availed when needed. It is said that the short-term memory stores around seven pieces of information at a time. Carrying over a number when doing addition or remembering information until a person stops talking are simple examples of short-term memory. It holds pointers or nexus that helps you associate with things
- Chunking – It is said that chunking a piece of information to smaller parts can lead to efficient functioning of the short-term memory. By holding information in small manageable chunks, it makes it easier to remember and utilize them. For example, a random big digit number can be split into three digits which will make it easy to recollect.
- Long–Term Memory – Compared to the limited and fast decaying capacities of the sensory and short-term memory, long-term memory has the capacity to store wider information even for an entire life span. Short-term memories tend to become long-term with repeated rehearsal of it along with proper association.
For example, a phone number of a dear one can be held on to our memory for a long time with an eventual practice of it. While short-term memory relies on acoustic or visual storage of information, long-term memory holds onto semantical information based on meaningful associations.
- Explicit Memory – It is also known as declarative memory and refers to the memory of facts and events as it is. It is explicitly stored and recalled when needed.
- Implicit Memory – Also known as procedural memory, it is the unconscious awareness that stems from previous experiences and comes from practice or repetition of certain events. This memory is further broken down:
- Episodic Memory – It is based on our experiences according to our timeline. Simply put, it is like the autobiographical record of our life.
- Semantic Memory – It is a more structured record of our experiences based in terms of certain contexts or situations. For example, it is more of knowledge of things like capitals, vocabulary, food types, etc. wherein we attach meaning to it to recollect it at a later point.
- Retrospective Memory – It constitutes all of the above memory types that is basically a reminiscence of the past events
- Prospective Memory – It refers to the content of the future or simply remembering to perform a particular planned action like going for a doctor’s appointment. It is normally triggered by a cue of time or another event.
There are a number of memory disorders with varying levels of severity, but they occur due to problems of the neurological structure of our brains. It can hinder the storage and recollection of certain memories and can be progressive like Alzheimer’s or Huntington’s or can also be instantaneous with an immediate effect like after a bad head injury.
- Amnesia – Memory is disturbed or lost due to physical injury or neurological disease. There are different types of amnesia with varying levels of forgetfulness.
- Age-Associated Impairment – Age can cause a general deterioration of the memory function and cause absent mindedness. Most people’s memory remains stable through their 70’s and after that it can be a problem to remember things
- Dementia – It is progressive memory loss along with other symptoms of depression, difficulty in comprehending language and recollecting things
- Huntington’s – It is inherited and progressive neurological disorder that results in loss of memory and affect muscle coordination.
- Autism – It affects the working memory or short term memory by hindering focus and processing of information in the brain