Preschoolers begin to differentiate the times of events from throughout the lifespan

Relieved or disappointed? Children's understanding of how others feel at the cessation of events

People's emotional states are influenced not just by events occurring in the present but also by how events have unfolded in the past and how they are likely to unfold in the future. To what extent do young children understand the ways in which past events can affect current emotions even if they are no longer ongoing? In the current study, we explored children's ability to understand how others feel at the cessation of events-as events change from being present to being past. We asked 97 4- to 6-year-olds (40.2% female) and 35 adults (54.3% female) to judge how characters felt once particular types of events had ended relative to how they felt during these events. We found that from age 4, children judged (as adults do) that the character would feel positive at the cessation of negative events-what we refer to as temporal relief. This understanding of relief occurs earlier than has been shown in previous research. However, children were less likely than adults to judge others as feeling sad at the cessation of positive events-what we refer to as temporal disappointment. Overall, our findings suggest that children not only understand that the cessation of events can affect others' emotions but also recognize that people feel differently following the cessation of positive, negative, and neutral events.

Towards a neurodevelopmental cognitive perspective of temporal processing

The ability to organize and memorize the unfolding of events over time is a fundamental feature of cognition, which develops concurrently with the maturation of the brain. Nonetheless, how temporal processing evolves across the lifetime as well as the links with the underlying neural substrates remains unclear. Here, we intend to retrace the main developmental stages of brain structure, function, and cognition linked to the emergence of timing abilities. This neurodevelopmental perspective aims to untangle the puzzling trajectory of temporal processing aspects across the lifetime, paving the way to novel neuropsychological assessments and cognitive rehabilitation strategies.

Children gradually construct spatial representations of temporal events

English-speaking adults often recruit a "mental timeline" to represent events from left-to-right (LR), but its developmental origins are debated. Here, we test whether preschoolers prefer ordered linear representations of events and whether they prefer culturally conventional directions. English-speaking adults (n = 85) and 3- to 5-year-olds (n = 513; 50% female; ~47% white, ~35% Latinx, ~18% other; tested 2016-2018) were told three-step stories and asked to choose which of two image sequences best illustrated them. We found that 3- and 4-year-olds chose ordered over unordered sequences, but preferences between directions did not emerge until at least age 5. Together, these results show that children conceptualize time linearly early in development but gradually acquire directional preferences (e.g., for LR).

You can't change the past: Children's recognition of the causal asymmetry between past and future events

This study explored children's causal reasoning about the past and future. U.S. adults (n = 60) and 3-to-6-year-olds (n = 228) from an urban, middle-class population (49% female; ~45% white) participated between 2017 and 2019. Participants were told three-step causal stories and asked about the effects of a change to the second event. Given direct interventions on the second event, children of all ages judged that the past event still occurred, suggesting even preschoolers understand time is irreversible. However, children reasoned differently when told that the second event did not occur, with no specific cause. In this case, 6-year-olds and adults inferred that the past event also did not occur. In both conditions, inferences that future events would change emerged gradually between 4 and 6.

The future is in front, to the right, or below: Development of spatial representations of time in three dimensions

Across cultures, people frequently communicate about time in terms of space. English speakers in the United States, for example, might "look forward" to the future or gesture toward the left when talking about the past. As shown by these examples, different dimensions of space are used to represent different temporal concepts. Here, we explored how cultural factors and individual differences shape the development of two types of spatiotemporal representations in 6- to 15-year-old children: the horizontal/vertical mental timeline (in which past and future events are placed on a horizontal or vertical line that is external to the body) and the sagittal mental timeline (in which events are placed on a line that runs through the front-back axis of the body). We tested children in India because the prevalence of both horizontal and vertical calendars there provided a unique opportunity to investigate how calendar orientation and writing direction might each influence the development of the horizontal/vertical mental timeline. Our results suggest that the horizontal/vertical mental timeline and the sagittal mental timeline are constructed in parallel throughout childhood and become increasingly aligned with culturally-conventional orientations. Additionally, we show that experience with calendars may influence the orientation of children's horizontal/vertical mental timelines, and that individual differences in children's attitudes toward the past and future may influence the orientation of their sagittal mental timelines. Taken together, our results demonstrate that children are sensitive to both cultural and personal factors when building mental models of time.

Neural Correlates of Temporal Presentness in the Precuneus: A Cross-linguistic fMRI Study based on Speech Stimuli

The position of any event in time could be in the present, past, or future. This temporal discrimination is vitally important in our daily conversations, but it remains elusive how the human brain distinguishes among the past, present, and future. To address this issue, we searched for neural correlates of presentness, pastness, and futurity, each of which is automatically evoked when we hear sentences such as "it is raining now," "it rained yesterday," or "it will rain tomorrow." Here, we show that sentences that evoked "presentness" activated the bilateral precuneus more strongly than those that evoked "pastness" or "futurity." Interestingly, this contrast was shared across native speakers of Japanese, English, and Chinese languages, which vary considerably in their verb tense systems. The results suggest that the precuneus serves as a key region that provides the origin (that is, the Now) of our time perception irrespective of differences in tense systems across languages.

"What Should You Bring with You to This Place?": Examining Children's Episodic Foresight Using Open-Ended Questions

Children's episodic foresight, the ability to mentally project oneself into the future to pre-experience an event (e.g., Atance & O'Neill, 2005), begins to emerge early in the preschool years. Results from the Picture-book task (Atance & Meltzoff, 2005) have shown that children are generally capable of selecting an item needed in the future (from provided options), but young preschoolers have difficulty justifying their choice with future-oriented explanations. Because episodic foresight has typically been measured using forced-choice questions (such as the Picture-book task) less is known about children's more naturalistic and "open-ended" future thinking (i.e., more spontaneous forms of episodic foresight). Forty-eight 3-to 5-year-olds completed a new, open-ended version of the Picture-book task. Using a descriptive approach, we found that children were able to generate an appropriate item to bring with them to a future location, and that this ability improved with age. Temporal focus as well as internal (episodic) and external (semantic) details were explored in the context of children's explanations. Children's explanations were mostly present-oriented and included episodic and semantic details equally. Our findings extend our knowledge of children's episodic foresight by highlighting children's ability to solve future-oriented problems in an open-ended manner.

Children's Memory for Temporal Information: The Roles of Temporal Language and Executive Function

The ability to recall the temporal order of events develops much more slowly than the ability to recall facts about events. To explore what processes facilitate memory for temporal information, we tested 3- to 6-year-old children (N = 40) for immediate memory of the temporal order of events from a storybook, using a visual timeline task and a yes/no recognition task. In addition, children completed tasks assessing their understanding of before and after and the executive functions of inhibition using the Day/Night Stroop task and cognitive shifting using the Dimensional Change Card Sort (DCCS) task. Older children (Mage = 69.25 months) outperformed younger children (Mage = 52.35 months) on all measures; however, the only significant predictor of memory for the temporal ordering of events was cognitive shifting. The findings suggest that the difficulty in memory for temporal information is related to development of a general cognitive ability, as indexed by the DCCS, rather than specific temporal abilities.

The Development of Temporal Concepts: Linguistic Factors and Cognitive Processes

Temporal concepts are fundamental constructs of human cognition, but the trajectory of how these concepts emerge and develop is not clear. Evidence of children's temporal concept development comes from cognitive developmental and psycholinguistic studies. This paper reviews the linguistic factors (i.e., temporal language production and comprehension) and cognitive processes (i.e., temporal judgment and temporal reasoning) involved in children's temporal conceptualization. The relationship between children's ability to express time in language and the ability to reason about time, and the challenges and difficulties raised by the interaction between cognitive and linguistic components are discussed. Finally, we propose ways to reconcile controversies from different research perspectives and present several avenues for future research to better understand the development of temporal concepts.

Thinking in and about time: A dual systems perspective on temporal cognition

We outline a dual systems approach to temporal cognition, which distinguishes between two cognitive systems for dealing with how things unfold over time – a temporal updating system and a temporal reasoning system – of which the former is both phylogenetically and ontogenetically more primitive than the latter, and which are at work alongside each other in adult human cognition. We describe the main features of each of the two systems, the types of behavior the more primitive temporal updating system can support, and the respects in which it is more limited than the temporal reasoning system. We then use the distinction between the two systems to interpret findings in comparative and developmental psychology, arguing that animals operate only with a temporal updating system and that children start out doing so too, before gradually becoming capable of thinking and reasoning about time. After this, we turn to adult human cognition and suggest that our account can also shed light on a specific feature of humans’ everyday thinking about time that has been the subject of debate in the philosophy of time, which consists in a tendency to think about the nature of time itself in a way that appears ultimately self-contradictory. We conclude by considering the topic of intertemporal choice, and argue that drawing the distinction between temporal updating and temporal reasoning is also useful in the context of characterizing two distinct mechanisms for delaying gratification.

Time and Narrative: An Investigation of Storytelling Abilities in Children With Autism Spectrum Disorder

This study analyzed the relation between mental time travel (MTT) and the ability to produce a storytelling focusing on global coherence, which is one of the most notable characteristics of narrative discourse. As global coherence is strictly tied to the temporal sequence of the events narrated in a story, we hypothesized that the construction of coherent narratives would rely on the ability to mentally navigate in time. To test such a hypothesis, we investigated the relation between one component of MTT—namely, episodic future thinking (EFT)—and narrative production skills by comparing the narratives uttered by 66 children with high-functioning autism spectrum disorder (ASD) with those produced by 66 children with typical development. EFT was assessed by administering a task with minimal narrative demands, whereas storytelling production skills were assessed by administering two narrative production tasks that required children to generate future or past episodes with respect to the target stimuli. The results showed that EFT skills were impaired only in a subgroup of children with ASD and that such subgroup performed significantly worse on the narrative production task than ASD participants with high EFT skills and participants with typical development. The practical and theoretical implications of these findings are discussed.

The mental timeline is gradually constructed in childhood

When reasoning about time, English-speaking adults often invoke a "mental timeline" stretching from left to right. Although the direction of the timeline varies across cultures, the tendency to represent time as a line has been argued to be ubiquitous and primitive. On this hypothesis, we might predict that children also spontaneously invoke a spatial timeline when reasoning about time. However, little is known about how and when the mental timeline develops, or to what extent it is variable and malleable in childhood. Here, we used a sticker placement task to test whether preschoolers and kindergarteners spontaneously map temporal events (breakfast, lunch, and dinner) and deictic time words (yesterday, today, tomorrow) onto lines, and to what degree their representations of time are adult-like. We found that, at age 4, preschoolers were able to arrange temporal items in lines with minimal spatial priming. However, unlike kindergarteners and adults, most preschoolers did not represent time as a line spontaneously, in the absence of priming, and did not prefer left-to-right over right-to-left lines. Furthermore, unlike most adults, children of all ages could be easily primed to adopt an unconventional vertical timeline. Our findings suggest that mappings between time and space in children are initially flexible, and become increasingly automatic and conventionalized in the early school years.

The cognitive bases of the development of past and future episodic cognition in preschoolers

The aim of this study was to use a minimalist framework to examine the joint development of past and future episodic cognition and their underlying cognitive abilities in 3- to 5-year-old Turkish preschoolers. Participants engaged in two main tasks, a what-where-when (www) task to measure episodic memory and a future prediction task to measure episodic future thinking. Three additional tasks were used for predicting children's performance in the two main tasks: a temporal language task, an executive function task, and a spatial working memory task. Results indicated that past and future episodic tasks were significantly correlated with each other even after controlling for age. Hierarchical multiple regressions showed that, after controlling for age, the www task was predicted by executive functions, possibly supporting binding of episodic information and by linguistic abilities. The future prediction task was predicted by linguistic abilities alone, underlining the importance of language for episodic past and future thinking.

Did the popsicle melt? Preschoolers' performance in an episodic-like memory task

Episodic memory has been tested in non-human animals using depletion paradigms that assess recollection for the "what", "where" and "when" (i.e., how long ago). This paradigm has not been used with human children, yet doing so would provide another means to explore their episodic memory development. Using a depletion paradigm, preschool-aged children were presented in two trials with a preferred food that was only edible after a short interval and a less-preferred food that was edible after the short and long intervals. Younger (mean = 40 months) and older (mean = 65 months) children tended to choose their preferred food after the short intervals, but did not switch to selecting their less-preferred food after the long intervals. Importantly, their choices did not differ with age. Although older children better remembered "what", "where", and "what is where" than did younger children, neither age group successfully estimated "how long ago" an event occurred. Finally, both age groups spontaneously recalled information about Trial 1. We also analysed the relation between the different measures used in the study but no clear patterns emerged. Results are discussed with respect to the cognitive mechanisms necessary to succeed in depletion paradigms and the measurement of episodic memory more broadly.

Brief report: episodic foresight in autism spectrum disorder

Episodic foresight (EpF) or, the ability to imagine the future and use such imagination to guide our actions, is an important aspect of cognition that has not yet been explored in children with autism spectrum disorder (ASD). This is despite its proposed links with theory of mind (ToM) and executive function (EF), two areas found to be impaired in ASD. Twenty-five children with ASD (M = 5 years, 10 months; 22 male) and 25 mental-age-matched typically developing children (M = 4 years, 10 months; 22 male) completed a series of EpF, ToM, and EF tasks. Significant group differences were detected on several EpF tasks suggesting that children with ASD show impairments in thinking about their future selves.

From memory to prospection: what are the overlapping and the distinct components between remembering and imagining?

Reflecting on past events and reflecting on future events are two fundamentally different processes, each traveling in the opposite direction of the other through conceptual time. But what we are able to imagine seems to be constrained by what we have previously experienced, suggesting a close link between memory and prospection. Recent theories suggest that recalling the past lies at the core of imagining and planning for the future. The existence of this link is supported by evidence gathered from neuroimaging, lesion, and developmental studies. Yet it is not clear exactly how the novel episodes people construct in their sense of the future develop out of their historical memories. There must be intermediary processes that utilize memory as a basis on which to generate future oriented thinking. Here, we review studies on goal-directed processing, associative learning, cognitive control, and creativity and link them with research on prospection. We suggest that memory cooperates with additional functions like goal-directed learning to construct and simulate novel events, especially self-referential events. The coupling between memory-related hippocampus and other brain regions may underlie such memory-based prospection. Abnormalities in this constructive process may contribute to mental disorders such as schizophrenia.

Episodic future thinking as a predictor of children's prospective memory

The primary goal of this study was to investigate the relationship among retrospective memory, episodic future thinking, and event-based prospective memory performance in preschool, first-grade, and second-grade children. A total of 160 children took part in the experiment. The study included participants from four age groups: 4-year-olds, 5-year-olds, 6-year-olds, and 7-year-olds. Participants were administered a recognition memory task, a task to test the ability to pre-experience future events, and an event-based prospective memory task. Data were submitted to correlational analyses, analyses of variance (ANOVAs), and logistic regression analyses. Results showed that, overall, all of these abilities improve with age and are significantly correlated with one another. However, when partialling out age and retrospective memory, episodic future thinking and prospective memory performance remained correlated. Logistic regression further showed that age and episodic future thinking abilities were significant predictors of prospective memory performance independent of retrospective memory abilities.

Episodic future thinking in children compared to adolescents

Episodic thinking involves the ability to re-create past and to construct future personal events, which contain event-specific (episodic) and general (semantic) details. The richness of episodic thought for past events improves as children move into adolescence. The current study aims to examine changes in episodic future thinking and to establish the cognitive underpinning of these changes. Typically developing children (n = 14) and adolescents (n = 15) were tested using an adapted version of the Child Autobiographical Interview (CAI) that required generation of past and future personally relevant events. Relational memory and executive skills were also examined. Significant developmental gains were found in richness of events recall across temporal directions (past and future) and across different types of details (episodic and semantic). Developmental gains in richness of past events were also shown to correspond to developmental gains in generation of future events. Moreover, developmental changes in relational memory and (to a lesser extent) executive functions were found to relate to increases in the amount of episodic (but not semantic) details provided. Our study highlighted the similarities between past and future episodic thinking in typically developing children and adolescents. It also raises a possibility that children with developmental and neurological disorders with impaired relational memory and/or executive skills may be at risk of difficulties with episodic thinking.

Assessing the role of memory in preschoolers' performance on episodic foresight tasks

A total of 48 preschoolers (ages 3, 4, and 5) received four tasks modelled after prior work designed to assess the development of "episodic foresight". For each task, children encountered a problem in one room and, after a brief delay, were given the opportunity in a second room to select an item to solve the problem. Importantly, after selecting an item, children were queried about their memory for the problem. Age-related changes were found both in children's ability to select the correct item and their ability to remember the problem. However, when we controlled for children's memory for the problem, there were no longer significant age-related changes on the item choice measure. These findings suggest that age-related changes in children's performance on these tasks are driven by improvements in children's memory versus improvements in children's future-oriented thinking or "foresight" per se. Our results have important implications for how best to structure tasks to measure children's episodic foresight, and also for the relative role of memory in this task and in episodic foresight more broadly.

The development of mental scenario building and episodic foresight

Episodic foresight is the future-directed counterpart of episodic memory. It is a sophisticated, potentially uniquely human capacity, with tremendous adaptive consequences. Here we review what is currently known about its development through early childhood. We tackle this from two distinct perspectives. First, we present the first systematic evaluation of the development of purported components of mental scenario building as highlighted by a theater metaphor: the stage, the playwright, the set, the actors, the director, the executive producer, and the broadcaster. We find that, although there are diverse developmental trajectories, by 4 years of age children have acquired the basic cognitive components required to mentally construct specific future events. Second, we examine recent attempts to test children's episodic foresight more directly and find that results are in line with those examining the development of required components. This is not to say that children younger than four have no inkling of upcoming events or that older children have nothing left to learn about constructing the future. Episodic foresight, and its neurocognitive foundations, continues to develop throughout childhood.

Episodic memory versus episodic foresight: Similarities and differences

There are logical and empirical grounds that link episodic memory and the ability to imagine future events. In some sense, both episodic memory and episodic foresight may be regarded as two sides of the same capacity to travel mentally in time. After reviewing some of the recent evidence for commonalities, I discuss limits of these parallels. There are fundamental differences between thinking about past and future events that need to be kept in clear view if we are to make progress in understanding the nature of mental time travel. The reviewed evidence suggests that mental time travel is based on a complex system selected not for accuracy about past and future per se, but for fitness benefits. Functional analyses promise to lead to fruitful avenues for future research. Copyright © 2009 John Wiley & Sons, Ltd. For further resources related to this article, please visit the WIREs website.