The processes of retrospective memory are essential for the smooth functioning of PM, as individuals must remember what they need to do and when to do it. Many researchers suggest that a successful PM combines two different cognitive processes: a retrospective component, to retain the content of the intention, and an executive processes, that acts at the appropriate time (Ellis, 1996; Kliegel et al., 2002; Mahy et al., 2014a; McDaniel et al., 1999; Smith et al., 2010; Zöllig et al., 2007). There is an agreement in the PM literature that underlines how prospective and retrospective processing components facilitate the realization of delayed intentions (Einstein et al., 1992; Guynn et al., 2001; Simons et al., 2006).

Executive functions (EF) are another significant driving force in the development of PM (Mahy et al., 2014a). There are different EF that are considered central to the development of PM: the shifting between tasks or mental sets (“Shifting”); the updating and the monitoring of working memory representations (“Updating”); the inhibition of prepotent responses in inappropriate content (“Inhibition”) (Mahy et al., 2014a; Mahy and Moses, 2011; Miyake et al., 2000). Specifically, monitoring has a crucial role in PM, and it can be both external and internal. Regarding the first, the environment must be monitored for the appearance of a PM signal. Regarding the second, individuals must also internally monitor their intentions to remember the content of their purpose, and realize it at the appropriate time (Mahy et al., 2014a).

Norman and Shallice (1986) proposed the theory of the attention system, in which the completion of PM tasks requires attentional resources, and the difficulty of an OT directly affects PM performance (Khan et al., 2008). OT and PM compete for attentional resources, decreasing PM performance (Han et al., 2017). An increase in the difficulty of an OT reduces the available attentional resources that can be assigned to a PM task, negatively affecting its performance (Bisiacchi et al., 2008; Han et al., 2017; Mahy et al., 2015). The effect of OT absorption on PM performance was analysed in children aged 9–10 years and 6–7 years; the results revealed that providing a less demanding OT resulted in better PM performance (Kliegel et al., 2013). Older children performed better in PM tasks because of increased attentive ability, while younger children had more limited attentional resources (Han et al., 2017; Mahy et al., 2015).

Metamemory emerges around 4 to 5 years old, and significantly improves across childhood and into adulthood (Godfrey et al., 2023; Schneider and Lockl, 2008). The knowledge of memory strategies could promote better PM performance. Several studies have shown that knowing about memory functioning (for instance the knowledge of metamemory) can improve people’s memory performance by having them implement appropriate strategies (Hutchens et al., 2012; Lachman and Andreoletti, 2006; McNamara and Scott, 2001). Once the repertoire of strategic metamemory is well stocked with knowledge, and memory skills are well developed, children are more likely to employ one or more strategies to effectively increase their memory performance (DeMarie et al., 2004).

Motivation to perform a task significantly impacts children’s performance (Carlson et al., 2005; Hongwanishkul et al., 2005; Kerr and Zelazo, 2004), and PM is no exception to this rule. Higher levels of intrinsic motivation improve children’s intention to perform PM tasks. In contrast, providing small incentives to remember trivial intentions does not seem to affect the performance of PM (Mahy et al., 2014a).

The Card Sorting Game is a paradigm proposed by Kvavilashvili et al. (2001) used to evaluate event-based PM in the 2 to 11 years age range (Figure 3). The task is presented as a game. Participants sort cards in four decks while naming the objects depicted and respond differently to certain target cards. Specifically, participants must call and sort, in a box, the cards of the deck (OT) while remembering to hide the target cards (PM task).

Different and numerous versions of this paradigm have been proposed. In the Morris the Mole version, participants name the objects depicted on the cards, place them face down on a box (OT), and hide the animal card (PM task). Other stimuli used in this version as PM cues are houses (Cejudo et al., 2019a; Ford et al., 2012; Kretschmer-Trendowicz et al., 2016; Kvavilashvili et al., 2001; Kvavilashvili and Ford, 2014; Mahy et al., 2016; Mahy and Moses, 2011, 2015; Szpakiewicz and Stępień-Nycz, 2024; Zhang et al., 2017). In the version adapted by Wang et al. (2008), participants should name the objects depicted on stickers placed on basketball balls (OT) and throw the ball into a basket when the image is an animal (PM task) (Wang et al., 2008). In the version adapted by Mahy et al. (2014b) and Zuber et al. (2019), participants order household items depicted on cards based on two categories: small or large objects (OT). Children ring a bell when they see a depicted animal (PM task) (Mahy et al., 2014b; Zuber et al., 2019). Finally, in the Zookeeper version, participants order animal cards in a yellow and blue box, according to the color of a sticker applied on each card (OT); participants, in addition, place the elephant card in a white box set behind them (PM task) (Lavis and Mahy, 2021). Through this PM task, a relationship between PM and chronological age was identified as one of the indicators of the developmental process (Ford et al., 2012). The results of studies conducted by different authors have shown that older children tend to be more efficient, make fewer errors and have shorter reaction times compared to younger children. A significant difference was found between preschool-aged children and school-aged children (Kretschmer-Trendowicz et al., 2016; Kvavilashvili et al., 2001); older children showed better performance on PM tasks (Cejudo et al., 2022; Cejudo et al., 2019a; Mahy et al., 2016; Mahy and Moses, 2011; Zhang et al., 2019). It is important to note that there was no floor effect in the younger group, indicating that they were already able to perform PM tasks (Wang et al., 2008). The development of PM has been shown to depend on the maturation of executive functions, including updating, shifting, inhibition, monitoring, and working memory (Cejudo et al., 2022; Ford et al., 2012; Mahy et al., 2016; Mahy and Moses, 2011; Wang et al., 2008; Zhang et al., 2019). These functions were identified as crucial for the reallocation of attention and the adaptation of strategies to the difficulty of the task. In addition, retrospective memory has been observed to influence reaction times in PM tasks (Wang et al., 2008).

The Picture Classification Task is a paradigm proposed by Einstein and McDaniel (1990) used to evaluate event-based PM in the 3 to 16 years age range (Figure 3). The task is presented as a computer game, and participants classify objects on the computer screen according to categories organized in blocks. Each block starts with the presentation of the image and the name of the class to be referenced. Participants classify ideas by responding through specific keyboard keys if the object is part of the requested category. Children respond by pressing a different key (i.e., the spacebar) when a target image appears on the screen (PM task).

As for the previous paradigm, different and numerous versions have been proposed. In the Karl and his dog Bubu version, participants answer if an object belongs to the category indicated (OT). In this version, the classes are five, represented by rooms: kitchen, bathroom, children’s room, study room, and wardrobe. Children press a specific keyboard key (i.e., spacebar) when an image of a sandwich, candy, or umbrella appears on the screen (PM task). Other stimuli used in this version as PM cues are types of fruit (Cottini et al., 2018, 2019, 2021a,b). In the version adapted by Guajardo and Best (2000), the stimuli presented are colouring images divided into six blocks (OT). Children press a specific key on the keyboard (i.e., the spacebar) when duck or house images appear (PM task) (Guajardo and Best, 2000). In the version by Basso et al. (2023), participants looked at 266 black-and-white drawings of living and non-living objects, which were presented one after the other in 32 lists of different lengths. They were asked to memorize the last three images of each list without knowing the length of the list and to indicate whether a test image was among these last three images by pressing “yes” or “no” on the keyboard (OT). They were also asked to press the space bar when pictures of a pig, a belt or a pumpkin appeared (PM task) (Basso et al., 2023). In the Shopping trip version, participants see 34 photos of shops: 12 stores are the targets for shopping; 22 are photos of shops where participants should not stop (OT). Elmo, a character from Sesame Street, was featured in some images, and children captured the character with a specific keyboard key (PM task) (Walsh et al., 2014). In the Arranging rooms for animals’ version, both time-based and event-based PM in children are evaluated. Participants should assign a corresponding colour (yellow, red, and blue) to the target category (dog, fish, and rooster) (OT). Children feed the rabbit with a carrot when the hourglass runs out (time-based PM task), and they provide the dog with a bone when the dog appears in the OT (event-based PM task) (Han et al., 2017). In the version used by Hartwig et al. (2021), participants see stills taken from the cartoons Party Animals and Strictly no dancing (OT). A bobble cap has been inserted in some stills. Children press a specific keyboard button each time they see a bobble cap (PM task) (Hartwig et al., 2021). The version adapted by Wang et al. (2024) is the only one that is exclusively time-based. Participants were shown 64 pictures of objects, animated or not. Participants had to determine whether the object in the picture shown was animated or inanimate by pressing the “F” or the “J” key on the computer (OT), respectively. Participants were asked to remember to press the “enter” key every 2 min (PM task) (Wang et al., 2024). In another version of this paradigm by Chen et al. (2017), participants observe the stimuli presented on the screen, 26 letters of the alphabet (OT). Children press a keyboard key when the letter “D” appears on the screen (PM task) (Chen et al., 2017). Another letter-based version was used by Kretschmer-Trendowicz et al. (2021), in which participants saw different sets of letter strings on the screen and had to indicate via the keyboard whether the presented strings were identical or not (OT). The children had to press a specific key on the keyboard when a sequence of letters “RLRLR” appeared on the screen (PM task) (Kretschmer-Trendowicz et al., 2021). Through this PM task, a relationship between PM and chronological age was identified as one of the indicators of the developmental process (Cottini et al., 2021a). The results of studies conducted by various authors have shown that older children tend to be more efficient and have shorter reaction times than younger children (Cottini et al., 2021a; Han et al., 2017). School-age children performed better than preschool children (Cottini et al., 2021b; Han et al., 2017; Hartwig et al., 2021). PM is subject to significant developmental changes during the primary school years (Chen et al., 2017). Results suggest that PM performance in children improves with age (Walsh et al., 2014); three-year-old children have at least a basic understanding of effective PM strategies, as even three-year-old children can use PM in a computer task (Guajardo and Best, 2000). Five-year-old children perform better than younger children on PM tasks at short and long intervals (Guajardo and Best, 2000). Twelve-year-old children were more efficient at performing the PM task compared to eight-year-olds (Cottini et al., 2021a). Using a reminder improved students’ PM accuracy (Chen et al., 2017). Executive functions, especially monitoring and working memory, were essential for successful PM in children (Cottini et al., 2018, 2019; Han et al., 2017; Hartwig et al., 2021). Attention is crucial in children’s PM tasks (Han et al., 2017). Metamemory was critical for PM development, as older children’s predictions and post-dictions were closer to actual PM performance than younger children’s; metamemory significantly improved children’s PM performance, primarily using predictions as strategies (Cottini et al., 2021a,b). Motivating children with rewards can improve their performance on PM tasks (Han et al., 2017). PM and RM performance of younger children were correlated (Han et al., 2017). PM and RM followed the same developmental trajectory. The contribution of retrospective memory promoted success in PM performance (Walsh et al., 2014).

The Cyber Cruiser is a paradigm proposed by Kerns (2000) used to evaluate time-based PM in the 5 to 14 years age range (Figure 3). The task is presented as a computer game, and participants simulate driving a vehicle. They control the vehicle using a joystick or a computer keyboard. Participants get points by going fast on the track without hitting the other vehicles (OT) and monitoring the vehicle’s fuel (PM task). The vehicle’s power is refilled by pressing a specific button only when it becomes visible on display. In the Cyber Cruiser version, children drive a car while avoiding obstacles (OT) and refuel it when the fuel level in the tank is low (PM task) (Kerns, 2000; Kliegel et al., 2013; Mahy et al., 2015; Voigt et al., 2014; Voigt et al., 2015; Zuber et al., 2019). In the Cyber Cruiser II version, children drive a spaceship while avoiding obstacles (OT) and refuel the spacecraft when the fuel level in the tank is low (PM task) (Cheie et al., 2021). Studies show that the Cyber Cruiser task is suitable for a wide age range and makes cognitive demands that arouse children’s interest (Kerns, 2000; Kliegel et al., 2013). The Cyber Cruiser requires participants to observe the passage of time without explicit temporal cues, which encourages initiative and strategic monitoring (Cheie et al., 2021). School-aged children have shown better PM performance compared to preschool-aged children (Zuber et al., 2019). Therefore, older children show better PM performance compared to younger children (Cheie et al., 2021; Kerns, 2000; Kliegel et al., 2013; Mahy et al., 2015; Voigt et al., 2015). Possible ceiling effects were excluded in the older group (Kliegel et al., 2013). Executive functions such as updating, inhibition, shifting and monitoring improve with age and are crucial for PM performance (Cheie et al., 2021; Kerns, 2000; Kliegel et al., 2013; Mahy et al., 2015; Voigt et al., 2015; Zuber et al., 2019). Children performed worse under conditions of divided attention than under conditions of sustained attention (Mahy et al., 2015). Retrospective memory has been identified as a valuable component in task performance (Kliegel et al., 2013).

The Virtual Week is a paradigm adapted from Rendell and Craik (2000) used to assess both time-and event-based PM in the 7 to 12 years age range (Figure 3). The task is presented as a computer board game and is a simulation of everyday situations in a virtual week. During the game, participants roll a die to move a token on a board and make choices between various alternatives offered by the game, such as choosing their preferred breakfast (OT). Children complete tasks that are typical of their daily lives, which are presented on the board and on activity cards. These tasks can be time-based, such as using an inhaler for asthma at 11:00 and 21:00 (time-based PM task). They can also be event-based, such as taking antibiotics at breakfast and dinner (event-based PM task). Participants must complete eight PM tasks in each ‘virtual day’ of the game. Four of these tasks are regular, consisting of two time-based PM tasks and two event-based PM tasks that are common in the lives of children. The other four tasks are considered irregular, consisting of two time-based PM tasks and two event-based PM tasks that are less frequent in the life of children (Terrett et al., 2019; Yang et al., 2011). Between the ages of 7 and 11, PM performance improved linearly and stabilized at age 12, with occasional errors. The first major improvement occurred between the ages of 7 and 8, with an increase in the frequency of recall of PM tasks and fewer errors of omission (Yang et al., 2011). Between the ages of 8 and 10, development was slower but steady, with a decrease in omission errors and a significant reduction in repetition errors, indicating a qualitative improvement. At age 10 to 11 years, there was a further significant improvement with an increase in the number of remembered PM tasks, and the level of PM performance remained stable until the age of 12 (Yang et al., 2011). The concentration and reading demands of the Virtual Week game make it unsuitable for children under the age of 8, and reliability has only been established for children aged 8 to 12 (Terrett et al., 2019). Retrospective memory supported PM performance by enhancing the inclusion of details of the PM task (Terrett et al., 2019). Children’s accuracy in PM tasks improved with age. Executive functions, particularly working memory and inhibition, were correlated with PM (Yang et al., 2011).

The Fishing Game is a paradigm proposed by Yang et al. (2011) to assess both time-and event-based PM in the 6 to 12 years age range (Figure 3). The task is presented as a computer game and participants catch as many fish as possible to earn points (OT). The children were exposed to two different game conditions. In the first condition, children stop fishing when they encounter a fish with certain characteristics to feed the cat next to the game avatar (event-based PM task). In the second condition, children stop the current activity when the digital clock in the upper right corner of the screen reaches the full minute to feed the cat next to the game avatar (time-based PM task) (Cheie et al., 2021; Yang et al., 2023; Yang et al., 2011). Using this PM task, it was found that performance increased with age (Cheie et al., 2021; Yang et al., 2011). Children aged 6 to 10 years had to perform the PM action when the digital clock showed 1:00, 2:00 and 3:00. These processes May be related to children’s learning of time and numerical skills (Cheie et al., 2021; Yang et al., 2011). The Fishing Game might be a better choice for cross-cultural studies as it requires less linguistic effort and only simple mouse operations (Yang et al., 2011). Executive functions – such as updating, inhibition, shifting, monitoring and working memory – improved performance in PM (Cheie et al., 2021; Yang et al., 2011).

The Ask for stickers is a paradigm used to evaluate event-based PM in the 2 to 15 years age range (Figure 3). The task is presented as a game. Participants play with an experimenter performing different tasks or games (OT) and must remember to pick up a gift (stickers or snacks) when the experimental session ends (PM task) (Causey and Bjorklund, 2014; Guajardo and Best, 2000; Hashimoto et al., 2022; Kelly et al., 2023; Ślusarczyk et al., 2018; Ślusarczyk and Niedźwieńska, 2013; Walsh et al., 2014). Using this PM task, it was found that children’s PM performance improved with age (Walsh et al., 2014). Older children showed better PM performance compared to younger children (Guajardo and Best, 2000). PM performance improved systematically during the preschool years (Ślusarczyk and Niedźwieńska, 2013). Preschool-aged children can fulfil a delayed intention if they are motivated to do so (Causey and Bjorklund, 2014). Two-year-old children can perform PM tasks to a certain extent if the motivation to complete the task is sufficiently high (Ślusarczyk and Niedźwieńska, 2013). Two-year-old children are not able to benefit from longer retention intervals (Ślusarczyk et al., 2018). The incentive for children to retain the object to be memorized could explain the performance of three-year-olds (Guajardo and Best, 2000). The children remembered asking for the sticker more often than asking to close the door or asking for the pencil. This result suggests that interest in obtaining the sticker facilitated remembering this task (Guajardo and Best, 2000). Preschool children showed good PM when the task was important to them (Causey and Bjorklund, 2014). Children needed multiple reminders to recall the intention (Kelly et al., 2023). Executive functions, especially working memory and inhibitory control, were essential for the development of PM (Causey and Bjorklund, 2014; Guajardo and Best, 2000; Ślusarczyk and Niedźwieńska, 2013). Differences in the development of executive functions, especially working memory, could also explain differences in PM performance in preschool-aged children (Guajardo and Best, 2000). High motivation was necessary for two-year-olds to perform well and remained an important factor that increased performance throughout the preschool years (Causey and Bjorklund, 2014; Guajardo and Best, 2000; Ślusarczyk and Niedźwieńska, 2013). PM and retrospective memory performance were correlated in younger children (Guajardo and Best, 2000). The contribution of retrospective memory facilitated success in PM performance (Walsh et al., 2014).

The Sightseeing tour is a paradigm used to evaluate both time-based and event-based PM in the 10 to 12 years age range (Figure 3). The task is presented as a game. Children participate in a Sightseeing tour structured in four attractions (OT) and remember to carry out activities required by the experimenter (PM task). The participants are on a bridge during the first attraction and must throw balls in a bucket. Participants stack small wooden sticks at the second attraction to build a tower as high as possible. During the third attraction, participants copy a painting. Finally, the fourth stop is dedicated to solving enigmas with matches (OT). Children receive six instructions for prospective activities: three social PM tasks with experimenter interaction (S) and three neutral PM tasks without interaction (N). S1: give the experimenter a handkerchief when sneezing; S2: fill one glass of water as soon as the experimenter empties it; S3: provide the experimenter with a pen at the end of the tour. N1: put a ticket in a box at the end of the tour; N2: pin an image on a bulletin board when the experimenter places a photo on a red chair; N3: wear a jacket when the experimenter opens the window (PM task) (Zhang et al., 2019). Using this PM task, it was found that PM performance improved in childhood (Kretschmer-Trendowicz et al., 2019). Children May not yet have acquired the competence to spontaneously apply advanced strategies, whereas adolescents, due to their greater knowledge of strategies, can use them to ensure good performance when given additional time (Kretschmer-Trendowicz et al., 2019). Research has shown no significant differences between neutral and socially delayed intentions in PM tasks (Kretschmer-Trendowicz et al., 2019). Retrospective memory, especially by encoding future episodic thoughts as a strategy, contributed to the improvement of PM (Kretschmer-Trendowicz et al., 2019).

The MISTY is a paradigm adapted by Raskin et al. (2010) used to assess both time-based and event-based PM in the 4 to 15 years age range (Figure 3). The task is presented as a paper-and-pencil test. The MISTY is structured similarly to the MIST (Raskin et al., 2010), a test employed in neuropsychology to assess prospective memory in adults. In the MISTY, participants solve a crossword puzzle (OT) while performing eight PM tasks. Half of the tasks aim to assess time-based PM (e.g., “in two minutes, at 3:05, tell me to do my homework”), while the other half aim to assess event-based PM (e.g., “when I hand you a blue pen, draw a house”) (PM task) (Mills et al., 2021). Additionally, children must answer eight multiple-choice questions presented by the experimenter (e.g., “When I gave you a blue marker, were you supposed to…? 1. Draw a house? 2. Draw a picture of your family? 3. Draw a cat?”), which are administered to test recognition memory (Mills et al., 2021). Using this PM task, it was found that PM performance increased significantly with age (Mills et al., 2021). Comparisons between age groups 4–6, 7–8, 9–10, 11–12 and 13–15 years showed significant differences in overall PM performance, indicating consistent improvements with age (Mills et al., 2021). These improvements are related to the development of retrospective memory, working memory and executive functions (Mills et al., 2021). The good reliability between the items and subscales of the MISTY indicates that they consistently measure the same construct.

The Mouse task is a paradigm adapted from Lejeune et al. (2013) used to evaluate time-based PM in the 4 to 9 years age range (Figure 3). The task is presented as a computer game, and participants use the inverted mouse to interact with the stimuli on the screen. In the “easy” version, participants capture the image of a cartoon character appearing on the screen and place it in a basket at the bottom of the screen. In the “hard” version, participants outline a triangular shape and capture several toys that appear on the screen (OT). Children must remember to press a specific key on the computer keyboard (i.e., spacebar) within 30 s whenever cartoon characters reach a red area on the screen (PM task) (Geurten et al., 2016). Executive functions, especially monitoring, had a positive impact on children’s PM performance. Knowledge of working memory strategies can be used to improve PM performance in childhood (Geurten et al., 2016).

The Puzzle/Math problems/Reading task/Find the differences is a paradigm used to evaluate event-based PM in the 6 to 13 years age range (Figure 3). The task is presented as a game, and participants perform four tasks in a constant order: a puzzle, reading, find differences, and math problems (OT). The experimenter asks the children to remember each task’s stimulus (PM task).

In the puzzle task, participants complete a puzzle (OT); at the end of the task, children must remember to put all the puzzle pieces in the box except for two unused pieces (PM task). In the reading task, participants read sentences from a notebook and emphasize words that refer to animals (OT); they must remember to circle the words referring to numbers (PM task). In the find the differences task, participants find differences between two images (OT); they must indicate with an arrow the most challenging difference to find (PM task). In the math problems task, participants solve math problems (OT); they must circle number 3 (PM task) (Cejudo et al., 2019b). In Shum et al. (2008), participants read a story (OT). The 8–9 year olds read a story entitled “The Twig Fence” and had to replace the character’s name “Henry” with “Tom” (PM task), while the 12–13 year olds read “The Fire” and had to replace the term “Lower Palmer” with “Upper Palmer” (PM task) (Shum et al., 2008). This PM task showed that older children achieved better results than younger children. The reaction times indicated that maintaining intention was a greater challenge for younger children. Accuracy in task performance also showed a similar pattern, with differences between younger and older children depending on the focality of the cue (Cejudo et al., 2019b). From a young age, children can use preparatory attentional processes and monitoring strategies for PM cues that influence their performance on the OT. These improvements are likely related to the development of executive functions in childhood. Moreover, motivation played a crucial role in PM performance during their development (Cejudo et al., 2019b).

The Reminding task is a paradigm used to evaluate both time-based and event-based PM in the 2 to 4 years age range (Figure 3). The task is presented as a verbal request. Caregivers provide indications of activities to remember, only once. Every day the caregiver gives participants 10 min to remember to do the activity without help. Participants must remember to carry out prospective activities in everyday life (OT). Children remember to perform caregivers’ requests at the appropriate times (i.e., 3:30 pm; time-based PM task) or at a suitable event (i.e., “when Dad comes home”; event-based PM task) (Somerville et al., 1983). The success in retrieving PM performance was evident even in younger children. Children aged 2, 3, and 4 showed remarkable competence in deliberately recalling the tasks presented to them (Somerville et al., 1983). On average, they recalled high-interest tasks with a short delay without prompting 73% of the time, with 2-year-olds recalling without prompting 80% of the time. These results suggested that the children were able to spontaneously recall high-interest tasks. Overall, performance on high-interest tasks was significantly higher than on low-interest tasks. In addition, motivation and high-interest tasks promoted success in retrieving PM tasks, even in younger children (Somerville et al., 1983).

Starting from retrospective memory, there were inconsistencies among different studies (Wang et al., 2008). In the study by Kvavilashvili et al. (2001) regression analyses did not show a relationship between children’s PM and retrospective memory scores, as retrospective memory did not significantly affect PM performance (Wang et al., 2008). Some studies showed that the two forms of memory were not correlated (Brandimonte and Passolunghi, 1994; Einstein and McDaniel, 1990; Guajardo and Best, 2000; Kidder et al., 1997), while other studies showed that PM and retrospective memory were closely related during the early stages of cognitive development (Ślusarczyk et al., 2018). Mahy et al. (2014b) suggested that retrospective memory involvement was necessary to recall predicted intention (Zhang et al., 2017). Indeed, this could have repercussions for preschoolers who did not remember the PM task instructions at the end of the procedure (Kliegel and Jäger, 2007; Zhang et al., 2017). Retrospective memory was involved in the development of PM, as children, thanks to this cognitive function, remembered what had to be done (Guajardo and Best, 2000). So, retrospective memory supported PM performance, improving the ability to code and maintain PM task requirements. The formation of more detailed intentions during the coding phase of a planned intention could increase the probability that the action would be performed later (Chasteen et al., 2001; Kliegel et al., 2000; Zhang et al., 2017). Individuals, therefore, needed to retrospectively recall the associations between cues and intentions to perform, thus initiating the PM process (Mills et al., 2021).

Metamemory also seemed necessary for the proper functioning of PM at developmental age. When a task had to be remembered in the future, it helped to construct, imagine, or remember it in advance; all these activities are based on metamemory (Causey and Bjorklund, 2014; Cejudo et al., 2019a; Geurten et al., 2016). Although children generally overestimate their specific performance (Cottini et al., 2019), the ability to form a flexible mental representation of an expected task and the environmental conditions that allow for its execution, appear to facilitate PM (Causey and Bjorklund, 2014). Simulating or imagining future events has been a successful PM strategy for school-age children (Causey and Bjorklund, 2014; Cottini et al., 2018). Kvavilashvili and Ford (2014) believed that PM performance was more accurate in children who better predicted their performance because they chose predictions as the most appropriate strategy to tackle the PM task (Cejudo et al., 2019a). Indeed, the relationship between performance predictions and actual performance was significant (Kvavilashvili and Ford, 2014). Performance predictions could be used, at school age, to facilitate the success of PM goals by facilitating the execution of the planned intention.

The studies included in this systematic review also showed an essential role of EF as possible mechanisms underlying the observed improvements in PM development (Cottini et al., 2019; Geurten et al., 2016; Hartwig et al., 2021; Shum et al., 2008; Voigt et al., 2015; Walsh et al., 2014). PM development in childhood depends mainly on the development of executive functioning (Cheie et al., 2021; Zuber et al., 2019). Rather than age itself, EF led to improved PM performance during childhood (Atance and Jackson, 2009; Ford et al., 2012; Kerns, 2000; Wang et al., 2008; Zuber et al., 2019). Indeed, the immaturity of these functions and underlying brain structures likely limited PM in young children (Walsh et al., 2014), especially under conditions of high cognitive demand during OT (Mahy and Moses, 2015; Shum et al., 2008; Ward et al., 2007). Different EF—working memory, inhibition, set switching, planning, and monitoring—played more prominent roles than others at certain PM stages (Mahy et al., 2014a), resulting in initial encoding, retention, and retrieval of intentions (Chen et al., 2017). Inhibitory control predicted performance accuracy (Cottini et al., 2018; Mahy and Moses, 2015) and was significantly correlated with PM of children and adolescents (Zuber et al., 2019). Inhibitory mechanisms, in developmental age, were necessary to interrupt the OT and allow for other intended actions, ignoring irrelevant information (Cheie et al., 2021; Kerns, 2000; Kliegel et al., 2013; Voigt et al., 2015; Zuber et al., 2019). The distribution of cognitive resources and children’s success in PM tasks also depended on refresher resources, mainly involved in PM action planning, regularly maintaining and reactivating OT and PM activity instructions (Mahy et al., 2014a; Zuber et al., 2019; Cheie et al., 2021). The dual-task situation, OT and PM, overloads the cognitive abilities of young children (Voigt et al., 2015), so strategic monitoring was a crucial process to ensure the success of a PM activity (Voigt et al., 2015; Zuber et al., 2019) There was a positive relationship between the strategic time monitoring score and the performance of PM even when their resources were involved in a cognitively challenging OT (Costa et al., 2010; Geurten et al., 2016; Mäntylä et al., 2007; Voigt et al., 2015; Zinke et al., 2010). Several studies have found a relationship between working memory capacity and PM (Ford et al., 2012; Hartwig et al., 2021; Mahy and Moses, 2011; Yang et al., 2011). Working memory is another critical factor in prospective memory’s accuracy and success (Cottini et al., 2018). Increasing this ability in older children supported the effectiveness of keeping the intention active (Hartwig et al., 2021), keeping the information in mind even during a delay (Kerns, 2000). Finally, displacement skills can support information monitoring, ensuring more flexible shifts between OT and PM tasks (Kliegel et al., 2013; Voigt et al., 2015).

Motivation had a powerful impact on PM in childhood, both for preschool and schoolchildren (Ślusarczyk et al., 2018). Studies that considered the relationship between PM and motivation showed that increasing motivation, both verbally and with material rewards, significantly improved PM performance (Han et al., 2017; Ślusarczyk et al., 2018). Children were susceptible to incentive manipulation (Causey and Bjorklund, 2014; Guajardo and Best, 2000; Ślusarczyk et al., 2018); in fact, the results showed more success in performing a PM task when it was personally rewarding to do so (Causey and Bjorklund, 2014). In addition, young children, compared to older children, had more limited cognitive resources, so motivation could help allocate their cognitive resources to the salient aspects of a task (Zhang et al., 2017).

As for attention, the results indicated a significant impact of age and attention on PM performance (Cejudo et al., 2019a; Cottini et al., 2021b; Cottini and Meier, 2020; Mahy et al., 2015; Smith et al., 2010). Typically, school-age children could actively adjust the allocation of their attention resources to different tasks depending on their level of motivation (Han et al., 2017). The allocation of attentive resources in children when completing a PM task was an organic combination of both “top-down” and “bottom-up” processes (Han et al., 2017). Older children can shift their focus more flexibly between the OT (attentional focus) and the future goal. Younger children seemed to have difficulty with these changes, which resulted in the detection of fewer PM signals (Mahy et al., 2015).