The document discusses human memory and its key components. It describes the three main stages of memory as encoding, storage, and retrieval. There are three main types of memory: sensory memory, short-term/working memory, and long-term memory. Sensory memory briefly stores perceptions, short-term memory holds information for seconds, and long-term memory can store information indefinitely. Long-term memory includes declarative memory (facts and experiences) and procedural memory (skills and habits). The document also discusses why we remember and forget, and provides tips for improving memory like paying attention, creating associations, and getting sleep.

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Table of Contents
Memory:............................................................................................................................................2
Encoding:.......................................................................................................................................2
Storage:.........................................................................................................................................3
Retrieval:........................................................................................................................................3
Types of memory:...............................................................................................................................4
Sensory memory:............................................................................................................................5
Short-term (working memory):........................................................................................................6
Long-term Memory:........................................................................................................................8
Declarative memory:...................................................................................................................9
 Episodic memory:................................................................................................................9
 Semantic memory:...............................................................................................................9
Procedural memory:....................................................................................................................9
Why we remember whatwe remember:............................................................................................10
Why we forget things ?.....................................................................................................................10
How to improve memory ?................................................................................................................11
References:......................................................................................................................................13

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Memory:
emory refers to the processes that are used to acquire, store, retain, and later
retrieve information. Memory is involved in processing vast amounts of
information. This information takes many different forms, e.g. images, sounds or
meaning. For psychologists the term memory covers three important aspects of information
processing: Encoding, Storage, and Retrieval.
In order to form new memories, information must be changed into a usable form, which occurs
through the process known as encoding. Once information has been successfully encoded, it
must be stored in memory for later use. Much of this stored memory lies outside of our
awareness most of the time, except when we actually need to use it. The retrieval process allows
us to bring stored memories into conscious awareness.
Encoding:
Encoding is the crucial first step to creating a new memory. It allows the perceived item of
interest to be converted into a idea that can be stored within the brain, and then recalled later
from short-term or long-term memory. Encoding is a biological event beginning with perception
through the senses.
There are three main types of encoding:
 Acoustic encoding is the processing and encoding of sound, words and other auditory
input for storage and later retrieval.
 Visual encoding is the process of encoding images and visualsensory information. Visual
sensory information is temporarily stored within the iconic memory before being
encoded into long-term storage.
 Semantic encoding is the process of encoding sensory input that has particular meaning
or can be applied to a particular context, rather than deriving from a particular sense.
M

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It is believed that, in general, encoding for short-term memory storage in the brain relies
primarily on acoustic encoding, while encoding for long-term storage is more dependent on
semantic encoding.
Storage:
Is the more or less passive process of retaining information in the brain, whether in the sensory
memory, the short-term memory or the more permanent long-term memory. Each of these
different stages of human memory function as a sort of filter that helps to protect us from the
flood of information that confront us on a daily basis, avoiding an overload of information and
helping to keep us sane. The more the information is repeated or used, the more likely it is to be
retained in long-term memory.
Retrieval:
Recall or retrieval of memory refers to the subsequent re-accessing ofevents or information from
the past, which have been previously encoded and stored in the brain. In common parlance, it is
known as remembering. During recall, the brain "replays" a pattern of neural activity that was
originally generated in response to a particular event, echoing the brain's perception of the real
event. In fact, there is no real solid distinction between the act of remembering and the act of
thinking.
Memories are not stored in our brains likebooks on library shelves,or even as a collection of self-
contained recordings or pictures or video clips, but may be better thought of as a kind of collage
or a jigsaw puzzle, involving different elements stored in disparate parts of the brain linked
together by associations and neural networks. Memory retrieval therefore requires re-visiting
the nerve pathways the brain formed when encoding the memory, and the strength of those
pathways determines how quickly the memory can be recalled. Recall effectively returns a
memory from long-term storage to short-term or working memory, where it can be accessed.

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Types of memory:
What we usually think of as “memory” in day-to-day usage is actually long-term memory, but
there are also important short-term and sensory memory processes, which must be worked
through before a long-term memory can be established. The different types of memory each
have their own particular mode of operation, but they all cooperate in the process of
memorization, and can be seen as three necessary steps in forming a lasting memory.
There are three types of memory:
 Sensory memory
 Short-term memory
 Long-term memory

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Sensorymemory:
Sensory memory is the shortest-term element of memory. It is the ability to retain impressions
of sensory information after the original stimuli have ended. It acts as a kind of stimuli received
through the five senses of sight, hearing, smell, taste and touch, which are retained accurately,
but very briefly. For example, the ability to look at something and remember what it looked like
with just a second of observation is an example of sensory memory.
The stimuli detected by our senses can be either deliberately ignored, in which case they
disappear almost instantaneously, or perceived, in which case they enter our sensory memory.
This does not require any conscious attention and, indeed, is usually considered to be totally
outside of conscious control. Sensory memory is an ultra-short-term memory and decays or
degrades very quickly, typically (1/5 - 1/2 second) after the perception of an item. Indeed, it lasts
for such a short time that it is often considered part of the process of perception, but it
nevertheless represents an essential step for storing information in short-term memory.
Four types of sensory memories exist. Iconic memory is a fast decaying store of visual
information; a type of sensory memory that briefly stores an image which has been perceived for
a small duration. Echoic memory is a fast decaying store of auditory information, another type
of sensory memory that briefly stores sounds that have been perceived for short durations.
Haptic memory is a type of sensory memory that represents a database for touch stimuli. Smell
may actually be even more closely linked to memory than the other senses. Thus, smells may be
more quickly and more strongly associated with memories than the other senses, and memories
of a smell may persist for longer.

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Short-term(working memory):
Short-term memory acts as a kind of “scratch-pad” for temporary recall of the information which
is being processed at any point in time. It can be thought of as the ability to remember and
process information at the same time. It holds a small amount of information (typically around 7
items or even less) in mind in an active, readily-available state for a short period of time (typically
from 10 to 15 seconds, or sometimes up to a minute). However, this information will quickly
disappear forever unless we make a conscious effort to retain it, and short-term memory is a
necessary step toward the next stage of retention, long-term memory. The transfer of
information to long-term memory for more permanent storage can be facilitated or improved by
mental repetition of the information or, even more effectively, by giving it a meaning and
associating it with other previously acquired knowledge.
In 1974 Baddeley and Hitch proposed a "working memory model" that replaced the general concept of
short-termmemorywithan active maintenance of informationinthe short-termstorage.In this model,
workingmemoryconsistsof three basicstores:thecentral executive,the phonological loopandthe visuo-
spatial sketchpad.

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The central executive essentially acts as an attention sensory store. It channels information to
the three component processes: the phonological loop, the visuo-spatial sketchpad.
The phonologicalloop stores auditory information by silently rehearsing sounds or words in a
continuous loop: the articulatory process (for example the repetition of atelephone number over
and over again). A short list of data is easier to remember.
The visuo-spatial sketchpad stores visual and spatial information. It is engaged when performing
spatial tasks (such as judging distances) or visual ones (such as counting the windows on a house
or imagining images).
The short-term memory has a limited capacity, George Miller in 1956 suggest that the number of
objects an average human can hold in working memory (known as memory span) is between 5
and 9 (7 ± 2, which Miller described as the “magical number”, and which is sometimes referred
to as Miller's Law).The type or characteristics of the information alsoaffects the number of items
which can be retained in short-term memory. For instance, more words can be recalled if they
are shorter or more commonly used words, or if they are phonologically similar in sound, or if
they are taken from a single semantic category (such as sports, for example) rather than from
different categories, etc. There is also some evidence that short-term memory capacity and
duration is increased ifthe words or digits are articulatedaloud insteadofbeing read sub-vocally
(in the head).

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Long-term Memory:
Long-term memories are allthe memories we hold for periods of time longer than a few seconds;
long-term memory encompasses everything from what we learned in first grade to our old
addresses to what we wore to work yesterday. Long-term memory has an incredibly vast storage
capacity, and some memories can last from the time they are created until we die. Despite our
everyday impressions of forgetting, it seems likely that long-term memory actually decays very
little over time, and can store a seemingly unlimited amount of information almost indefinitely.
Short-term memories can become long-term memory through the process of linkage, involving
rehearsal and meaningful association. Unlike short-term memory (which relies mostly on an
acoustic, and to a lesser extent a visual, code for storing information), long-term memory
encodes information for storage semantically (i.e. based on meaning and association). However,
there is also some evidence that long-term memory does also encode to some extent by sound.
For example, when we cannot quite remember a word but it is “on the tip of the tongue”, this is
usually based on the sound of a word, not its meaning.
Long term memory is divided into :

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Declarativememory:
Declarative memory (“knowing what”) is memory of facts and events, and refers to those
memories that canbe consciouslyrecalled (or "declared"). It is sometimes calledexplicit memory,
since it consists of information that is explicitly stored and retrieved, although it is more properly
a subset of explicit memory. Declarative memory can be further sub-divided into episodic
memory and semantic memory.
 Episodic memory:
Episodic memory represents our memory of experiences and specific events in time in a serial
form, from which we can reconstruct the actual events that took place at any given point in our
lives. It is the memory of autobiographical events (times, places, associated emotions and other
contextual knowledge) that can be explicitly stated. It involves conscious thought and is
declarative. An example would be a memory of our 1st day at school.
 Semantic memory:
Semantic memory, on the other hand, is a more structured record of facts, meanings, concepts
and knowledge about the external world that we have acquired. It refers to general factual
knowledge, shared with others and independent of personal experience. It includes such things
as types of food, capital cities, social customs, functions of objects, vocabulary, understanding of
mathematics, etc. Much of semantic memory is abstract and relational and is associated with the
meaning of verbal symbols.
Proceduralmemory:
Procedural memory (“knowing how”) is the unconscious memory of skills and how to do things,
particularly the use of objects or movements of the body, such as tying a shoelace, playing a
guitar or riding a bike. These memories are typically acquired through repetition and practice,
and are composed of automatic sensorimotor behaviors that are so deeply embedded that we
are no longer aware of them. Procedural memory is sometimes referred to as implicit memory,
because previous experiences aid in the performance of a task without explicit and conscious
awareness of these previous experiences.

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Why we remember what we remember:
There are several reasons why information is stored in our short term memory:
 Primacy effect – information that occurs first is typically remembered better than
information occurring later. When given a list of words or numbers, the first word or
number is usually remembered due to rehearsing this more than other information.
 Distinctiveness – if something stands out from information around it, it is often
remembered better. Any distinctive information is easier to remember than that which
is similar, usual, or mundane.
 Frequency effect – rehearsal, results in better memory. Remember trying to memorize a
formula for math class. The more we went over it, the better we knew it.
 Associations – when we associate or attach information to other information it becomes
easier to remember. Many of us use this strategy in our professions and everyday life.
 Recency effect – often the last bit of information is remembered better because not as
much time has passed.
Why we forget things ?
The main reasons for forgetting include:
 Retrieval Failure:
One problem with memory involves knowing something is stored but being unable to retrieve
the information. The theory why this occurs is called memory decay, which suggests that each
new memory creates a ‘trace’ that can fade away if not accessed regularly.
 Ineffective Encoding:
The inability to remember information may sometimes have less to do with forgetting and more
to do with the fact that it never made its way into long-term memory. This type of forgetting is
caused becausethe person did not pay attention in the first place. Encoding failure or ineffective
coding may prevent information from entering long-term memory, and thus the information
never being stored to be able to be retrieved at a later date.

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 Decay Theory (Fading):
The Decay theory suggests that when something new is learned, a memory “trace” is formed in
the brain and over time the trace begins to fade and disappear, unless it is occasionally
used. With this theory, if information is not occasionally retrieved, it will eventually be lost.
 Subconscious mind and forgetting:
One theory states that the subconscious mind sometimes omits certain things from your
memory if it doesn't believe that they are important. If for example someone promised a friend
that he will meet him then forgot completely about that promise then this might mean that
subconscious mind doesn't believe that meeting that person will be useful to him.
How to improve memory ?
 pay attention:
Often when we “forget” something, it’s not that we’ve lost the memory but that we didn’t learn
the thing properly in the first place. If you pay full attention to what you are trying to learn, you’ll
be more likely to remember it later.
 Listen carefully:
Instead of just reading information silently, read it aloud. You will encode the information aurally
as well as visually. You can also try writing it out; the act of writing activates sensory systems and
also forces you to think about the words you’re copying.
 Create associations:
When studying unfamiliar or some new material, take the time to think about how this
information relates to what is already known. By establishing relationships between new ideas
and previously existing memories, you can dramatically increase the likelihood of recalling the
recently learned information.

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 Elaborate and rehearse:
In order to recallinformation, you need to encode what you are studying into long-term memory.
One of the most effective encoding techniques is known as elaborative rehearsal. An example of
this technique would be to read the definition of a key term, study the definition of that term
and then read a more detailed description of what that term means.
 Get some sleep:
Researchers have long known that sleep is important for memory and learning. Research has
shown that taking a nap after you learn something new can actually help you learn faster and
remember better. In fact, one study found that sleeping after learning something new actually
leads to physical changes in the brain.

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References:
 https://www.verywellmind.com/what-is-memory-2795006
 https://www.simplypsychology.org/memory.html#def
 http://www.human-memory.net/processes_recall.html
 https://en.wikipedia.org/wiki/Memory
 https://courses.lumenlearning.com/boundless-psychology/chapter/introduction-to-
memory/
 https://allpsych.com/psychology101/memory/
 http://thepeakperformancecenter.com/educational-
learning/learning/memory/forgetting/
 https://smallbiztrends.com/2014/11/memory.html

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