Prospective Memory (PM) is the memory that involves being able to remember and perform planned action at certain time. Prospective memory tasks can range from remembering to remove food from the oven after a certain time to remembering to take medication at a particular point in the day. It is defined by Eysenck as “remembering to carry out intended actions without being instructed to do so” it typically focuses on when to do something, and has low informational content. Shimara at al (1991) argued that prospective memory includes every day skills such as planning and decision making (Groot, Y.C et al (2002) Prospective memory functioning in people with and without brain injury. Journal of the International Neuropsychological Society: JINS, 8(5), pp645-654).
Studies have found that anxiety has a negative effect on PM (based on correlations).
Baseline data by Mash, Hicks and Landau (1998) established that although people made on average 15 plans per week, 25% of them were not completed, with 3% of them being forgotten.
Prospective memory is a part of executive functions: cognitive processes that regulate, control and manage thoughts etc. There are different types of prospective memory:
1. Event- based: remembering to do something when a particular event occurs. An example being "I must remember to ask Dr. Levita about my lab report when i next see her"
2. Time-based: remembering to do something at a particular time. An example being "I must remember to go to Dr Levita's office at 3pm to ask her that question about my lab report"
3. Activity- based: remembering to do something after you have completed a specific task. This can be "I must remember to email Dr. Levita my lab report draft when i finish it"
Einstein and McDaniel (1990) argued time-based prospective memory places more emphasis on self initiated retrieval and so consequently is more difficult (Groot, Y.C et al (2002) Prospective memory functioning in people with and without brain injury.
Cockburn (1995) proposed that an inhibitory control mechanism has a part in prospective memory function. His case study supported the finding that time-based PM is more difficult than event-based PM. (Groot, Y.C et al (2002) Prospective memory functioning in people with and without brain injury. Journal of the International Neuropsychological Society: JINS, 8(5), pp645-654).
Prospective vs retrospective memory
Differences between Prospective Memory and Retrospective Memory
Our ability to remember people, words and events encountered from the past is our retrospective memory (RM). Retrospective memory differs in many ways from our prospective memory (PM):
1. RM involves remembering what we know about someone or something, and this can involve recalling a lot of information. Whereas PM is associated with remembering when to do something, and this does not require as much information.
2. Cockburn (1995) suggested that remembering prospectively also requires memory for intention, and that this remembering has to be self initiated.
3. Whilst PM has to be self initiated, there can be a number of external cues available when remembering retrospectively. For example someone may ask you something about your childhood.
Theories of Prospective Memory:
Preparatory Attentional and Memory Theory (PAM) (Smith, 2003; Smith & Smith and Bayen, 2004) According to this theory, two types of processes are used to be able to perform a task: Monitoring process constructs and maintains the intention until it is performed and retrospective memory is used to differentiate between the wanted prospective memory intention and unwanted thoughts. PAM is engaged throughout ongoing activity.
Multi-process model (McDaniel and Einstein, 2007) An automatic process is used for some retrieval but strategic processes are used for retrieval in other conditions. Monitoring plays a role in important tasks and when PM target events are not salient; as well as when there is no pre-association between target event and intended action.
Model of attentional control of behaviour (Norman and Shallice, 1986) General executive function not specific to PM. Made up of supervisory attentional system and contention schedular. Schemas govern behaviour and are activated either by environmental cues or modulating activity by SAS.
Theory of monitoring (Guynn, 2008) Complementary to existing theories of PM. Says monitoring has 2 processes that demand resources: initiating PM retrieval and monitoring environment for appropriate time to conduct intended action.
Neural correlates of PM:
Gilbert et. al (2012) found an overlay of areas activated during encoding, retrieval of delayed intentions and maintenance of intentions. Their explaination was that the prefrontal cortex is used for executive function while the parietal cortex and hippocampus are used in retrospective memory.