Introduction
When we try to recall a planned intention or to remember to perform a planned action, we retrieve information from the prospective memory of our brain. In other words, a memory of something that needs to be done in the future. Prospective memory refers to the ability to plan, retain, and retrieve a premeditated time, event, or activity-based task.
Since the planned event that we try to retrieve from memory is to take place at some future point in time, this type of memory is also referred to as a memory of the future or remembering to remember.
What Are the Characteristics of Prospective Memory?
Prospective memory is characterized by:
- Meaningful association with an intended action;
- Salience or distinctiveness;
- Ability to focus on future events and tasks;
- Need for planning;
- Reliance on self-initiated retrieval of previously stored information.
What Is the Function of Prospective Memory?
Prospective memory enables us to perform previously planned actions or intentions at a future point of time. For example, this type of memory is activated when we need to remember to congratulate a friend on their birthday, submit the project application on time, etc.
In a future time-based prospective memory task:
- the planned activity must be remembered in order to be performed at a particular time (e.g., to see the dentist tomorrow at 1 p.m.),
- in an event-based task, the information needs to be recalled when the particular event occurs (e.g., to remember to buy milk on the way),
- in an activity-based task, the planned activity and information must be remembered after the completion of another activity (e.g., send a report after the meeting).
What Are the Types of Prospective Memory?
There are two types of prospective memory:
- Event-based prospective memory, and
- Time-based prospective memory.
Event-based Prospective Memory
Event-based prospective memory refers to the type of memory that is utilized when something needs to be done at a future point in time. For this intention to be realized, we are reminded by a planned or unplanned event. Consequently, we can distinguish two event-based prospective memory subtypes:
- Immediate-execute prospective memory,
- Delayed-execute prospective memory.
Some examples of immediate-execute (planned) and delayed-execute (unplanned) prospective memory are:
- going to bed or eating a meal (planned intention), or
- seeing a T-shirt on the chair which reminds you to clean your wardrobe (unplanned intention).
The second type of prospective memory is more common, and the information stored in the delayed-execute prospective memory is easier to remember.
Time-based Prospective Memory
The time-based prospective memory is activated when something needs to be done at a specific time in the future. This type of prospective memory is usually the first to show signs of decline and is susceptible to memory disorders.
Since it’s necessary to have a strong focus and attention on the task, as well as the recollection of a determined point in time, the information stored in the prospective memory is more difficult to be remembered.
Two Theories Explaining Why People Remember Future Tasks
The Monitoring Theory and the Multiprocess Theory are only two of the wide range of theories that explain the function of the prospective theory.
The Monitoring Theory
According to the Monitoring Theory, remembering to do a delayed task requires effort, preparation, and monitoring. It involves checking for cues and refreshing (revising and repeating) an intended task in the working memory because it can be easily forgotten if we are not fully concentrated and engaged in it.
The Multi-Process Theory
According to this theory, there are 2 general processes:
- Monitoring and
- Spontaneous retrieval.
The spontaneous retrieval of prospective memory refers to an automatic, cue-triggered process where the intention ‘appears’ in the mind.
Which Brain Structures Are Involved in Prospective Memory?
In order to remember to perform future tasks, prospective memory makes use of the following cerebral cortex structures:
- Frontal lobe,
- Parietal lobe,
- Hippocampus,
- Thalamus,
- Anterior and posterior cingulate cortex.
The frontal lobe is the most important structure when it comes to remembering and performing future tasks. This is due to the fact that a certain amount of episodic and semantic memory is required.
Frontal Lobe
The frontal lobe is the so-called ‘center of intelligence’ or a ‘control panel’ of our personality because it regulates and controls all intellectual processes: our memory, movement, attention, motivation, production of speech, and visual attention.
More specifically, Brodmann area 6 supports the regulation of the cognitive function performed by the cortical structures. This part of the frontal lobe of the cerebral cortex is the most evolved (rational) part of the brain, responsible for the most highly developed cognitive processes such as learning, speaking, memorizing, comprehension, etc.
Parietal Lobe
To receive and process sensory information is the main function of the parietal lobe. More specifically, the inferior parietal lobule helps us maintain focus and orientate our body in the space around us, which is one of the main characteristics of the prospective memory.
The parietal lobe also controls and regulates the information received through the retina of our eyes as well as the audio messages coming to the brain from the auditory organs.
Hippocampus
The hippocampus is involved in the processing of declarative (explicit) memories so that they can be used in the future.
It receives the neuronal connections from the primary sensory areas of the cortex. After this, it translates the stimuli and relates them to similar information from past knowledge that has been previously stored in the brain.
Thalamus
Almost all motor and sensory information (with the exception of information gained from the olfactory nerve) passes through the thalamus. This brain structure is considered as a sensory ‘crossroad’ of the brain since it receives the sensory information as a sensation. The cerebral cortex translates this sensation and further transmits it to its corresponding sensory centers as touch, pain, or temperature.
This small part of our brain has a huge role in filtering the information which reaches our brain centers by differentiating between significant and insignificant information. This, in turn, helps us concentrate and focus, which are some of the most important aspects of the prospective memory.
Regarding the prospective memory, it’s activated when the cues are recognized and acted upon during the planned tasks that rely on this type of memory.
Anterior and Posterior Cingulate Cortex
The functions of the anterior and posterior cingulate cortex of the brain include error detection, social evaluation, consciousness, registration and emotional association of pain, learning new skills, etc.
These brain structures house the Brodmann areas 23, 24, 31, 33, and 34, which are involved in some of the most important aspects of the prospective memory. They control motor preparation/planning, working memory, memory encoding, time-based memory, as well as retrieval of the autobiographical memory.
Prospective Memory and Everyday Life
We engage our prospective memory on a daily basis. It allows us to remember how to walk, talk, ride a bike, jump, run, skip, or drive a car. Forgetting to perform a planned task can have serious consequences in everyday life. People sometimes tend to forget to do time-based, event-based, or activity-based tasks that they consider to be very important.
When it comes to the prospective memory, the importance of a planned intention is based upon the values, desires, goals, and their predicted consequences.
Fun Facts
Did you know?
- Negative thoughts can lower the activity of the frontal lobe. In turn, this can result in bad memory and impaired cognitive functions of the brain.
- With the prospective memory, we actually ‘remember to remember’ something.
- Prospective memory tends to decline fast over time and as we age than all the other types of memory.
- Do it or snooze it! Do you regularly set up an alarm or reminder before an event? Do you have a habit of leaving post-it notes on your fridge to remind you what supplies you need to buy from the supermarket? Do you tend to leave yourself a voice message in order not to forget the time scheduled for a meeting with business partners, the hairdresser, or a friend? If so, then you can blame it on prospective memory.
- One of the biggest differences between the prospective memory and retrospective memory is the fact that they use different structures of the brain in order to perform their function.
- The prefrontal cortex is directly involved in recalling event-based prospective memories.
- No matter the age, several underlying causes can lead to problems with memory. Forgetfulness can occur due to stress, depression, lack of sleep, or thyroid gland dysfunction. Other causes include side effects from certain types of medicine, an unhealthy diet, or an insufficient intake of fluids in our body (dehydration).
- Remembering to send an e-mail or a letter just because we saw the mailbox is where the parietal lobe displays its involvement in prospective memory.
- Since the inferior parietal cortex is involved in the time-based prospective memory, any damage to this brain area could lead to a lackluster ability to track time effectively.
- Everybody forgets to do things you might think they would never have forgotten.