The creation of memories and how they’re stored is a complex mental process of gaining, storing, and recalling information, as well as the impressions and sensations that we have previously experienced.
The aforementioned process of storing memories involves many parts of the brain that aid our ability to remember some events, feelings, or facts in the long term, or in the short term.
What Is Short Term Memory?
Short term memory (also synonymous with primary memory, active memory, and working memory) is a complex process of temporarily storing and retrieving the information needed for the performance of complex cognitive tasks, such as learning, reasoning, and comprehension.
This type of memory relates to the part of our brains that holds onto information until we need to recall it. Short term memory has a slightly longer duration than the ultra-short sensory type of memories, but it still fleets away only after a minute or so. It’s very temporary, and it uses up an insignificant chunk of the brain’s storage capacity.
Each short-term memory consists of two parts: the ‘traditional’ short-term memory and working memory.
What Is Working Memory?
Working memory is the type of memory we use every day: when going to the supermarket, following a conversation, reading, writing, etc. It plays an important role in concentration and in following instructions, thus helping us stay focused and helping us follow the pattern of a given task correctly.
There are two types of working memory:
- A visual-spatial working memory – It retains visual information, i.e. what we see.
- An auditory working memory – It retains audio information, i.e. what we hear.
When our working memory doesn’t function well, it can affect our daily life and cause us to:
- Constantly forget where our keys, wallet, or phone is.
- Forget what we wanted to say before we manage to join the conversation.
- Plan to make a cake at home, but forget to buy the needed ingredients on our way back from the store.
- Get lost easily, despite the fact we have received the directions just a moment ago.
- Weak working memory skills can affect learning in many different subject areas including reading and math.
What Is the Difference Between Short Term Memory and Working Memory?
The term ‘short-term memory’ is used interchangeably with the term ‘working memory’.
Namely, short term memory refers to the process of temporary storage of information (such as remembering a new number in order to write it down).
On the other hand, working memory relates to the processing of information for the purpose of manipulating it (remembering a piece of information helpful only for the task we are doing at the moment).
How Is Short Term Memory Formed?
Certain regions of the brain’s cortex are labeled as primary sensory areas. Each of these areas receives sensory information from a specific sense which is further integrated with data from other senses, matched to memories and knowledge, and associated with feelings and emotions.
The primary visual cortex, for instance, analyzes data from the eyes. In this way, seeing a particular scene allows us to recognize, identify, and name the objects in it; remember where we saw them previously, recalling the related sensory data (smell, touch, sight, taste) and experiencing the associated emotions again.
First, the brain obtains information from the environment in the form of sensory stimuli. This activity is short – it lasts a few seconds at most. Then, the brain gains information from the sensory organs of sight and hearing. The formation of short-term memory begins by processing the received sensory information by the dedicated centers in the brain.
What Are the Different Types of Short Term Memory?
Apart from the short term memory, there are also several ultra-short types of memories that we can distinguish: sensory, iconic, echoic, and haptic memory.
Sensory Memory
Sensory memory is the first type of memory used by the brain to form new short-term and long-term memories. It is also sometimes called working memory.
This type of memory represents a remembered image, a scent, or a sound. It’s the shortest form of retained sensory information that experience through our five major senses – touch, taste, sight, hearing, and smell.
No matter if we’re dealing with sight, smell, or taste – sensory memories are fleeting. But, even though they’re an ultrashort type of memory, new short-term and long-term memories cannot be formed without them.
Iconic Memory
Iconic (visually representative) memories, just like sensory memories, are very fleeting. They’re a type of ultra-short visual memory that lasts just milliseconds before fading. This is the way our brain remembers an image we just saw moments ago.
Here’s an example: a boy is reading a book, while another one asks what the book is. As a joke, the first boy flashes the cover of the book for just a second before hiding it behind his back, leaving the second boy with only the impression, or iconic memory, of how the book’s cover looked.
Echoic Memory
Echoic (imitative of a sound) memories are ultra-short-term retention of the information received from the auditory stimuli. This type of memory is stored slightly longer than iconic memories. The duration is about four seconds.
Spoken language is the most common example of echoic memory. When someone talks, echoic memory retains each individual syllable. The brain recognizes the spoken words by connecting each syllable to the previous one. Each of those words is also stored as an echoic memory, which allows our brain to understand a full sentence.
Haptic Memory
This type of memory refers to memories involving the sense of touch. Sensory receptors located mainly in the skin receive sensations like pressure, itching, and pain. This sensory information is briefly contained in haptic memory before fading away or being transferred to short-term memory.
Haptic memory is as fleeting as iconic and echoic memory, it lasts no longer than two seconds. It’s the memory of how the sand feels under our bare feet, or how fabric feels on our skin.
Which Are the Brain Areas Associated With Memory?
Just like many of the intellectual processes are not controlled by just one area of the cerebral cortex, there isn’t a single region of the brain that processes all memory, or acts as a storage site for all memories.
The following is a list of neural networks located in various areas of the brain that are involved in memory:
- The putamen – Stores ‘subconscious’ memories, such as motor skills gained by repetition.
- The prefrontal cortex – Controls the mental retention of passing situations, such as the visual-spatial awareness of current surroundings, and is also involved in remembering semantic tasks.
- Hippocampus – Establishes declarative, episodic, and recognition memory, as well as knowledge linked with spatial awareness. It helps transfer immediate thoughts and sensory data into short and long term memories.
- Amygdala – Recalls powerful emotions associated with memorable events, such as fear or joy. It also plays a key role in forming new memories, specifically related to fear.
- Cortex – Stores parts of memory associated with specific senses and motor actions in their relevant areas.
- Temporal lobe – Stores sensory memory, as well as language, words, vocabulary, and speech.
- Cerebellum – Plays a role in processing procedural memories and motor learning, such as how to ride a bike.
However, the central part of the prefrontal cortex of the brain plays the most fundamental role in both short-term and working memory.
More specifically, short-term memory primarily takes place in the frontal lobe of the cerebral cortex of the brain. From here, the information is transmitted by the neurons to the designated area in the hippocampus.
For permanent storage, short-term memories are further transferred to the cerebral cortex areas which are involved in the processing of language and perception.
What’s the Role of the Prefrontal Cortex in Short Term Memory?
The prefrontal cortex (PFC) is the part of the neocortex located at the very front of the brain that is involved in numerous complex cognitive processes.
While its left side is more involved in verbal working memory (an ability to remember something and to perform an activity by using this type of short term memory), the right side of the prefrontal cortex is more active in spatial working memory.
What Causes Short Term Memory Loss?
When a person experiences short-term memory loss, he or she can remember incidents from 20 years ago, but can’t remember the details of things that happened 15 minutes ago.
There are numerous causes that can lead to a loss of short term memory. Also, some medical conditions can result in an inability to remember the short-term information retained in the brain:
- A lack of oxygen to the brain
- Alcohol
- Drug abuse
- Concussions and other head trauma
- Seizures
- Epilepsy
- Heart bypass surgery
- Depression
- A brain aneurysm
- A brain tumor
One of the first signs of dementia is short-term memory loss, also.
To Sum Up
Forming new memories is an exceptionally complex and fascinating process. It enables us to process our environment, improve behavior, and give context to our lives.
Short-term memory is the small amount of information that we remember for a short time. When we obtain information from the world that surrounds us, that information is retained in the brain as a mental representation of the experience, and it becomes retrievable for future use.
Fun Facts
Did you know?
- If the hippocampus suffers damage, a person could still recall events from long ago but will not be able to remember what happened a few hours before the injury occurred for example.
- Approximately, short term memory lasts between 20 and 30 seconds, holding about 7 items at a time.
- One of the first signs of dementia is short-term memory loss.
- There are four main reasons why we forget: failure to retrieve the stored information from the dedicated brain center, interference, failure of the brain to store the memory, as well as motivated forgetting.
- A familiar scent can bring us back a lot of memories associated with it.
- Iconic memory is so fleeting, that anything we remember beyond 0.50 seconds of time gets transferred into short term memory.
- A traumatic event can literally erase our memory from the brain.
- Auditory information is only stored in the echoic memory, visual information is stored in iconic memory, while tactile memories are stored in the haptic memory.
- The ultra-short iconic memory has a duration of about 100 ms.
- Working memory can be improved in several ways: by developing routines, using checklists for tasks with multiple steps, experimenting with various ways of remembering information, reducing multitasking, etc.