Prospective Memory

Understanding Prospective Memory

Memory in real life contexts does not only consist of a record of past events. As well as remembering what has happened in the past, we also use memory to store intentions and plans.

Most importantly, we need to remember to actually perform the intended actions, and memory is also involved in keeping track of ongoing actions and of the actions we intend to carry out in the future. This type of memory is known as prospective memory.

Prospective memory is memory for remembering Opens in new window to do something at a particular moment in the future.

Prospective memory is typically conceptualized as any intended action that must be completed in the future. First and foremost, this involves an intention to perform a future action being established in memory Opens in new window. Then, later, some aspect of the environment eventually triggers remembering to fulfill the intention (Einstein & McDaniel, 1990).

Whereas retrospective memory Opens in new window involves remembering events experienced in the past, prospective memory is memory for a future act Opens in new window. It includes remembering a plan of action (i.e. what to do) and also remembering to do it.

In most cases, the planned action has to be performed at a specified time, or within some time limits, so prospective memory also involves remembering when to perform the act.

In everyday life, prospective memory is almost continuously active. We go through the day employing prospective memory

  • to remember to pay the gas bill;
  • to phone a relative;
  • to give your house-mate the message that a friend called;
  • to buy more cat food;
  • to raise a point at a meeting;
  • to look up a reference in the library;
  • to pick up bread at the grocery on your way home and so on.

Prospective memory tasks Opens in new window are integrated into our work lives: The waiter must remember to pick up extra cream for a table on his way back to the kitchen, and an instructor has to remember to make sure the reserve readings for her class are available before meeting her seminar. Ellis described prospective memory as consisting of several phases:

  1. encoding an intention,
  2. maintaining the intention in memory while engaged in other ongoing activities,
  3. initiating the intention at the appropriate moment, and
  4. evaluating the outcome.

Prospective memory is also involved in activities that are critical to maintaining life. Remembering to take medication is a common example.

In some cases, failures of prospective remembering may have serious, or even catastrophic, consequences. Failure to remember to check the backseat of the car after an appropriate period of time has elapsed has produced tragic deaths for young children left in the car.

There are numerous examples in daily life of the potentially harmful consequences of forgetting to carry out an intention. Kvavilashvili, Messer, and Ebdon (2001) report that prospective memory failures represent 50–70% of everyday memory problems.

Examples of particularly serious prospective memory lapses include forgetting to take one’s heart medication, or a pilot forgetting to adjust the position of wing flaps before takeoff.

Event-Based versus Time-Based Prospective Memory

Prospective memory allows one to form and hold an intention about a future action until the time when one executes the intention in the action. There are numerous types of prospective memory Opens in new window. Two common types of prospective memory have been described in the literature:

  1. Event-based prospective memory, which involves remembering to perform an action when a specific external event occurs, such as giving a certain person a message.
  2. Time-based prospective memory involves remembering to perform an action at a particular time (or a fixed amount of time), such as pressing a key every 8 minutes, or at a fixed point in time, such as remembering an appointment at 1 P.M.

Both types of prospective memory depend on triggering or target cues in the environment that enable one to hold the intention and execute it in the appropriate place and at the appropriate time (McDaniel, Umanath, Epstein et al., 2015).

The duration of this process may be considerably longer than working memory Opens in new window, which typically lasts for only a few seconds.

Prospective memory may involve minutes, hours, days or even years. Prospective memory task Opens in new window depend on both a prospective and a retrospective component.

Prospective memory requires a certain store of retrospective episodic Opens in new window and semantic memory Opens in new window as a basis on which to initiate and complete temporally extended action plans.

The prospective component supports the realization that some prospective action is to be performed once an appropriate cue is encountered. The retrospective component, on the other hand, supports the ability to recall an intention when that prospective cue is detected.

Therefore, the prospective component involves remembering that something needs to be done; and the retrospective component supports remembering what it is that has to be done. Although these two components are interconnected, they are functionally distinct (Cohen, Dixon, Lindsay, & Masson, 2003).

Concepts and Complexities

Despeite the collective acknowledgement of prospective memory in everyday life, historically, researchers argued whether this emerging field of research was actually a distinct form of memory.

As Crowder (1996) famously argued in his chapter The Trouble with Prospective Memory: A Provocation, the loss of the term prospective memory would leave the field better off, probably because it implies that the task is purely a memory task.

Prospective memory involves a complex array of cognitive processes in addition to memory Opens in new window. Accordingly, the more neutral term realization of delayed intentions is sometimes used. In contrast, other researchers want to limit the focus of study to a memory process that is relatively unique to prospective memory tasks Opens in new window; these researchers favor the term prospective memory proper (Graf & Uttl, 2001).

Graf and Uttl (2001) rightly pointed that Crowder took issue with the idea that prospective memory was a distinct form of episodic memory Opens in new window; however, he did not doubt that memory Opens in new window can indeed be oriented to the future.

As a cognitive construct Opens in new window, prospective memory is complex, with many sub-domains. This may contribute to the difficulty with defining it. For example, a number of cognitive abilities have been implicated in prospective memory, including working memory Opens in new window, executive functioning, time perception, and retrospective memory Opens in new window, to name a few.

Perhaps Ellis and Kvavilashvili (2000) offered the most comprehensive definition of prospective memory:

Successful prospective remembering enables us to shape and direct our cognitive resources in the pursuit of future actions and plans. As such, it is a critical element in the coordination and control of cognitive skills that underlie our ability to complete many real-world activities. It should, therefore, no longer be regarded as an aspect of memory that lies on the fringes of cognitive psychology but s one that is central to developing our understanding of how intentions are translated into action”Ellis and Kvavilashvili. (p. 1, 2000)

The quote above effectively captures the expansive scope of prospective memory and acknowledges the role it plays in the formation of future actions and plans.

Pink and Dodson (2013) suggests a broader definition of prospective memory Opens in new window that includes the necessity of remembering to not perform an intention, if it has already been completed.

For example, a common prospective memory failure is performing an action when there is no need to do so (e.g., accidentally taking an additional dose of medicine).

Despite some of these early definitional struggles, the field of prospective memory has flourished and the number of papers on the topic continues to increase exponentially.

Prospective memory involves two neural pathways. A frontal-parietal pathway regulates attentional control processes in forming and maintaining an intention. This pathway also regulates how environmental cues indicate when the intention should be executed.

A second pathway in prospective memory involves the frontal-parietal cortex, hippocampus Opens in new window and anterior cingulated cortex (ACC). This pathway regulates retrieval of the memory and execution of the intention in action (McDaniel, Umanath, Einstein et al. , 2015).

Dysfunction in any of these regions can impair the capacity to recall earlier intentions and result in failure to perform actions. This is one example of how memory systems can be highly interactive, depending on the nature and duration of the cognitive, emotional or motor task at hand.

Intentions are basically action plans (Bratman, 2007). A voluntary action requires the ability to form and translate an intention into that action. Prospective memory enables one to anticipate performing an action and hold an intention to act until the appropriate time.

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