Development of time sensitivity and information processing speed

Psychometric properties of the Children's Time Awareness Questionnaire (CTAQ): A study on the validity of a Dutch 20-item questionnaire measuring time awareness in children

This study investigates the validity of Children's Time Awareness Questionnaire (CTAQ), a 20-item task for assessing children's time awareness. The CTAQ was administered to a group of typically developing children (n = 107) and children with any developmental problems reported by parents (non-typically developing children, n = 28), aged 4-8 years old. We found some support for a one-factor structure (EFA), yet the explained variance is relatively low (21%). Our proposed structure of two additional subscales, i.e., "time words" and "time estimation," was not supported by (confirmatory and exploratory) factor analyses. In contrast, exploratory factor analyses (EFA) indicated a six-factor structure, which needs further investigation. We found low, yet non-significant correlations between CTAQ scales and caregiver reports on children's time awareness, planning and impulsivity, and no significant correlations between CTAQ scales and scores on cognitive performance tasks. As expected, we found that older children have higher CTAQ scores than younger children. Non typically developing children had lower scores on CTAQ scales, compared to typically developing children. The CTAQ has sufficient internal consistency. The CTAQ has potential to measure time awareness, future research is indicated to further develop the CTAQ and enhance clinical applicability.

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.

Predicting Learning: Understanding the Role of Executive Functions in Children's Belief Revision Using Bayesian Models

Recent studies suggest that learners who are asked to predict the outcome of an event learn more than learners who are asked to evaluate it retrospectively or not at all. One possible explanation for this "prediction boost" is that it helps learners engage metacognitive reasoning skills that may not be spontaneously leveraged, especially for individuals with still-developing executive functions. In this paper, we combined multiple analytic approaches to investigate the potential role of executive functions in elementary school-aged children's science learning. We performed an experiment that investigates children's science learning during a water displacement task where a "prediction boost" had previously been observed-children either made an explicit prediction or evaluated an event post hoc (i.e., postdiction). We then considered the relation of executive function measures and learning, which were collected following the main experiment. Via mixed effects regression models, we found that stronger executive function skills (i.e., stronger inhibition and switching scores) were associated with higher accuracy in Postdiction but not in the Prediction Condition. Using a theory-based Bayesian model, we simulated children's individual performance on the learning task (capturing "belief flexibility"), and compared this "flexibility" to the other measures to understand the relationship between belief revision, executive function, and prediction. Children in the Prediction Condition showed near-ceiling "belief flexibility" scores, which were significantly higher than among children in the Postdiction Condition. We also found a significant correlation between children's executive function measures to our "belief flexibility" parameter, but only for children in the Postdiction Condition. These results indicate that when children provided responses post hoc, they may have required stronger executive function capacities to navigate the learning task. Additionally, these results suggest that the "prediction boost" in children's science learning could be explained by increased metacognitive flexibility in the belief revision process.

Seeing the Error in My "Bayes": A Quantified Degree of Belief Change Correlates with Children's Pupillary Surprise Responses Following Explicit Predictions

Bayesian models allow us to investigate children's belief revision alongside physiological states, such as "surprise". Recent work finds that pupil dilation (or the "pupillary surprise response") following expectancy violations is predictive of belief revision. How can probabilistic models inform the interpretations of "surprise"? Shannon Information considers the likelihood of an observed event, given prior beliefs, and suggests stronger surprise occurs following unlikely events. In contrast, Kullback-Leibler divergence considers the dissimilarity between prior beliefs and updated beliefs following observations-with greater surprise indicating more change between belief states to accommodate information. To assess these accounts under different learning contexts, we use Bayesian models that compare these computational measures of "surprise" to contexts where children are asked to either predict or evaluate the same evidence during a water displacement task. We find correlations between the computed Kullback-Leibler divergence and the children's pupillometric responses only when the children actively make predictions, and no correlation between Shannon Information and pupillometry. This suggests that when children attend to their beliefs and make predictions, pupillary responses may signal the degree of divergence between a child's current beliefs and the updated, more accommodating beliefs.

Children and adults rely on different heuristics for estimation of durations

Time is a uniquely human yet culturally ubiquitous concept acquired over childhood and provides an underlying dimension for episodic memory and estimating durations. Because time, unlike distance, lacks a sensory representation, we hypothesized that subjects at different ages attribute different meanings to it when comparing durations; pre-kindergarten children compare the density of events, while adults use the concept of observer-independent absolute time. We asked groups of pre-kindergarteners, school-age children, and adults to compare the durations of an "eventful" and "uneventful" video, both 1-minute long but durations unknown to subjects. In addition, participants were asked to express the durations of both videos non-verbally with simple hand gestures. Statistical analysis has revealed highly polarized temporal biases in each group, where pre-kindergarteners estimated the duration of the eventful video as "longer." In contrast, the school-age group of children and adults claimed the same about the uneventful video. The tendency to represent temporal durations with a horizontal hand gesture was evident among all three groups, with an increasing prevalence with age. These results support the hypothesis that pre-kindergarten-age children use heuristics to estimate time, and they convert from availability to sampling heuristics between pre-kindergarten and school age.

The effect of magnitude in a simultaneous duration assessment task among children - a replication study

The "magnitude effect" refers to the phenomenon where stimuli of greater magnitude appear to last longer in duration. Previous studies have explored this effect among children using various duration assessment tasks, but the findings have been inconsistent. Moreover, no replication studies have been conducted on this topic among children thus far. The simultaneous duration assessment task, which is one method for investigating time perception, has been used only twice in children and produced the magnitude effect. Thus, we aimed to replicate these findings and validate them through an additional replicated study. For these aims, we recruited 45 Arab-speaking children aged 7-12 to participate in two studies. In Study 1, they were asked to perform a simultaneous duration assessment task, where they had to assess the illumination durations of lightbulbs with strong and weak intensities simultaneously. In Study 2, they were asked to perform a duration reproduction task, where they had to reproduce the durations of illumination of the same stimuli. Both studies found a magnitude effect pattern, where the children tended to report that the lightbulb with the stronger intensity was illuminated for a longer duration or had a strong tendency to not choose the lightbulb with the weaker intensity. These results are discussed in terms of possible explanations for the conflicting results found in previous literature, as well as their consistency with the pacemaker model's explanation for the effect.

The ages of zone of proximal development for retrospective time assessment and anticipation of time event

From childhood to adulthood, an individual's ability to estimate and anticipate the timing of events changes continuously. This study investigated the ability of 287 children aged 5-14 years to estimate the duration of prior events and anticipate the timing of future events for determination of the age at which children improve their timing skills. The Luria neuropsychological assessment battery and the Wechsler Intelligence Scale for Children (WISC-IV) were applied to find correlations between timing skills and the development of cognitive functions. The findings demonstrated that retrospective estimation of duration has a zone of proximal development in children between the ages of six to eight; in these children, the accuracy of time assessment significantly improved after receiving the prompt. However, improvement in time estimation was significantly lower in those children who achieved lower results in the attention and memory tests and demonstrated reduced spatial and verbal reasoning skills. The zone of proximal development for the ability to anticipate the timing of future events was demonstrated in children between the ages of nine to eleven years. The improvement of time anticipation was negatively correlated with the number of mistakes made during the dynamic praxis test.

Detecting Time Concept Competence in Children with Autism Spectrum and Attention Disorders

The importance of time concept in human existence is "ancient history" celebrated in the biblical book Ecclesiastes. Indeed, our time-sensitive mechanisms are literally carved into our biology and neurology on a molecular level, gifting us with neural clocks. However, time in human consciousness is not the time indicated by physical clocks: time is a subjective reality in our psychological makeup due to the nature of the temporal neural mechanisms and unique properties of physical time. Nonetheless, subjective time requires anchoring to physical time which permeates our language, endeavors, and entire existence, a process hinging on time-related skills such as estimates and measures of passage and duration of time. Moreover, accurate time reading, a critical adaptive life-skill, is imperative for effective function in all societal activities. Because it embodies the complexity of the time construct, it is central to instruction of time concept in primary education. It is often measured in children by clock drawings, a cognitive integrative skill with errors pointing to neuroanatomical differences impacting the integrity of executive function. Time competence in children with atypical neurobiological development and high prevalence, as in autism spectrum disorders (ASD), and attention disorders (ADHD), is often compromised, calling for investigation of its function. This thematic review article aims to: 1) discuss the complexity of time concept and its underlying bio-neurological mechanisms, 2) elucidate difficulties children with ASD and those with ADHD exhibit in temporal development, and 3) demonstrate the use of a set of clinical tools in uncovering temporal competence and ecological executive function in two children with ASD, and a child with ADHD, using a clock drawing task and error analyses; children's time knowledge questionnaire; a behavior rating parent questionnaire examining ecological executive function, and parent open-ended questions related to their children's time difficulties. A discussion, directions, and a take-home message round out the article.

Simultaneous time processing in children and adults: When attention predicts temporal interference effects

Children from 5 to 8 years of age, as well as adults, performed a temporal reproduction task in both a solo-timing condition and a multi-timing condition, with different durations presented simultaneously. In the multi-timing condition, all durations were processed because the participants did not know in advance which stimulus needed to be judged. In a first experiment, two or three durations were presented with a synchrony of their onset. In a second experiment, two durations were presented simultaneously with asynchrony of their offset, different lengths of the concurrent duration, and different presentation orders. In addition, the participants' cognitive abilities in terms of selective attention, as well as short-term and working memory, were assessed with different neuropsychological tests. The results of both experiments showed that children and adults alike were able to process multiple durations simultaneously. However, the simultaneous presentation of different durations generated a temporal interference effect in children and adults, resulting in longer and more variable time estimates. This temporal interference effect was nevertheless higher in children due to their limited attention capacities. Therefore, a developmental improvement in the ability to process different durations simultaneously is related to the cognitive development of attention capacities.

Diagnostic criteria for temporomandibular disorders (DC/TMD) for children and adolescents: An international Delphi study-Part 1-Development of Axis I

Background

Since in children and adolescence prevalence is assessed mainly on self‐reported or proxy‐reported signs and symptoms; there is a need to develop a more comprehensive standardised process for the collection of clinical information and the diagnosis of TMD in these populations.

Objective

To develop new instruments and to adapt the diagnostic criteria for temporomandibular disorders (DC/TMD) for the evaluation of TMD in children and adolescents.

Method

A modified Delphi method was used to seek international consensus among TMD experts. Fourteen clinicians and researchers in the field of oro‐facial pain and TMD worldwide were invited to participate in a workshop initiated by the International Network for Orofacial Pain and Related Disorders Methodology (INfORM scientific network) at the General Session of the International Association for Dental Research (IADR, London 2018), as the first step in the Delphi process. Participants discussed the protocols required to make physical diagnoses included in the Axis I of the DC/TMD. Thereafter, nine experts in the field were added, and the first Delphi round was created. This survey included 60 statements for Axis I, and the experts were asked to respond to each statement on a five‐item Likert scale ranging from ‘Strongly disagree’ to ‘Strongly agree’. Consensus level was set at 80% agreement for the first round, and at 70% for the next.

Results

After three rounds of the Delphi process, a consensus among TMD experts was achieved and two adapted DC/TMD protocols for Axis I physical diagnoses for children and adolescents were developed.

Conclusion

Through international consensus among TMD experts, this study adapted the Axis I of the DC/TMD for use in evaluating TMD in children and adolescents.

Duration judgments in children and adolescents with and without mild intellectual disability

BACKGROUND

While the ability to measure time correctly is crucial for adaptation to the external physical and social environment, to date, research on timing ability and its development in individuals with intellectual disability (ID) is unfortunately remarkably scarce.

AIMS

In the present study, we investigated the ability of individuals with mild ID to estimate durations and the development of this ability from 11 to 19 years, in comparison to typically developing (TD) individuals.

METHODS AND PROCEDURES

Participants with mild ID and TD participants matched on chronological age completed two temporal tasks: (1) a temporal bisection of auditory stimuli, in which they had to decide whether arbitrary stimulus duration was more similar to the short (200 ms) or the long (800 ms) standard previously learned, and (2) a temporal categorization of familiar actions, in which short, medium or long target durations had to be paired with one of three comparison action durations.

OUTCOMES AND RESULTS

Temporal performance was systematically impaired in participants with mild ID. Moreover, the temporal impairment increased with age in the bisection task but not in the categorization task.

CONCLUSIONS AND IMPLICATIONS

These findings suggest that the ability to estimate durations develops at a slower pace in individuals with mild ID compared to TD individuals.

Spatial attention and representation of time intervals in childhood

Spatial attention and spatial representation of time are strictly linked in the human brain. In young adults, a leftward shift of spatial attention by prismatic adaptation (PA), is associated with an underestimation whereas a rightward shift is associated with an overestimation of time both for visual and auditory stimuli. These results suggest a supra-modal representation of time left-to-right oriented that is modulated by a bilateral attentional shift. However, there is evidence of unilateral, instead of bilateral, effects of PA on time in elderly adults suggesting an influence of age on these effects. Here we studied the effects of spatial attention on time representation focusing on childhood. Fifty-four children aged from 5 to 11 years-old performed a temporal bisection task with visual and auditory stimuli before and after PA inducing a leftward or a rightward attentional shift. Results showed that children underestimated time after a leftward attentional shift either for visual or auditory stimuli, whereas a rightward attentional shift had null effect on time. Our results are discussed as a partial maturation of the link between spatial attention and time representation in childhood, due to immaturity of interhemispheric interactions or of executive functions necessary for the attentional complete influence on time representation.

Comparison of temporal judgments in sighted and visually impaired children

AIM

We studied visually impaired and blind children to investigate the effects of visual damage on time perception.

METHODS

Sixty-three children (11 blind, 16 visually impaired, 20 sighted and 16 sighted but blindfolded) performed a temporal bisection task, which consisted of judging different temporal intervals presented in the auditory modality.

RESULTS

The visually impaired children showed lower constant error than sighted children but higher variability (Weber ratio). The blindfolded children had a temporal estimation comparable to the clinical groups and time sensitivity comparable to the controls.

CONCLUSION

These findings are interpreted in the light of inter-modality interference, assuming that the coexistence of both sensory modalities, present only in controls, leads to a trade-off between the two senses with an indirect contribution of sight, which does not happen either in the clinical groups or in the blindfolded children, despite the single sensory task.

Time perception and autistic spectrum condition: A systematic review

Problems with timing and time perception have been suggested as key characteristics of autism spectrum condition (ASC). Studies and personal accounts from clinicians, parents, caregivers, and self‐reports from autistic people themselves often refer to problems with time. Although a number of empirical studies have examined aspects relating to time in autistic individuals, there remains no clear consensus on whether or how timing mechanisms may be affected in autism. A key reason for this lack of clarity is the wide range of timing processes that exist and subsequently the wide range of methodologies, research paradigms, and samples that time‐based studies have used with autism populations. In order to summarize and organize the available literature on this issue, a systematic review was conducted. Five electronic databases were consulted. From an initial 597 records (after duplicates were removed), 45 papers were selected and reviewed. The studies are reviewed within different sections based on the different types of timing ability that have been explored in the neurotypical (NT) population: time sensitivity, interval timing, and higher‐order time perception. Within each section cognitive models, methodologies, possible clinical implications, and research results are discussed. The results show different consistency across studies between the three types of timing ability. The highest consistency of results showing atypical time perception abilities is found in high‐level time perception studies. It remains unclear if autism is characterized by a fundamental time perception impairment. Suggestions for future research are discussed. Autism Res 2019, 12: 1440–1462. © 2019 International Society for Autism Research, Wiley Periodicals, Inc.

Lay Summary

This systematic review examines the different types of timing and time perception behavior that have been investigated in autism. Overall, there are a number of studies that show differences between autistic and non‐autistic individuals, but some studies do not find such differences. Group differences are more consistent across studies using complex tasks rather than simpler more fundamental timing tasks. We suggest that experiments across a range of timing tasks would be fruitful to address gaps in our knowledge.

Children with autism spectrum disorder show increased sensitivity to time-based predictability

Objectives: We studied timed-based expectancy as well as general perceptual-motor speed in children with autism spectrum disorder (ASD). Methods: In Experiment 1, 11 children with ASD and 11 typically developing children (TD) (6-13 years) completed a binary choice response task in which foreperiod duration predicted the response target's location with a probability of 0.8. In Experiment 2, we compared performance between 10 children with ASD (6-11 years) and 10 TD children by using a simple reaction time test. Results: Employing a binary forced choice task where the duration of a pre-target interval (800 or 1400 ms) probabilistically predicted the target, we found that children with ASD were sensitive to the temporal regularity, whereas TD children were not. Children with ASD were faster for expected combinations of interval and target location but they were also less accurate for those combinations. Results from an additional simple reaction time test indicate that the development of general perceptual-motor processes was delayed in children with ASD. However, the ability for children with ASD to form time-based expectancies was not correlated with their performance in the simple reaction time test. Conclusion: Children with ASD show significantly greater sensitivity towards time-based predictability than TD children. However, the development of general perceptual-motor processes was impaired in children with ASD.

Children's concepts of childhood and adolescent depression

BACKGROUND

Research on adolescent Mental Health Literacy (MHL) is rapidly increasing; however, equivalent research in children is lacking. Exploring children's mental health conceptualisations reveals how their knowledge develops and provides the evidence base for the development of mental health education for younger age groups.

METHODS

A total of 105 children aged 8-9 and 11-12 years were interviewed using a vignette methodology structured according to the model of illness representations, exploring: recognition, causes, consequences, timeline and curability of depression. Age, gender and experience differences were explored.

RESULTS

Children were able to identify the existence of a psychological difficulty in a depressed peer; however, they struggled to categorise depression as a mental illness or to label depression. Children referred to a variety of causal factors, primarily environmental and interpersonal rather than internal biological causes. Children considered depression to be curable within a short period of 1-2 months and anticipated negative outcomes if left untreated. Older children's concepts were more sophisticated than younger children's. Gender and experience were not associated with depression concepts in this age range.

CONCLUSIONS

Age trends in children's mental health concepts are evident, in accordance with previous studies. Children from the age of 8-9 years demonstrate detailed concepts of depression. However, mental health educational interventions are needed to target specific gaps and misconceptions in children's understanding.

A divergence of sub- and supra-second timing abilities in childhood and its relation to academic achievement

Work with adult humans and nonhuman animals provides evidence that the processing of sub-second (<1 s) and supra-second (>1 s) durations are modulated via distinct cognitive and neural systems; however, few studies have explored the development of these separate systems. Moreover, recent research has identified a link between basic timing abilities and academic achievement, yet it is unclear whether sub-second and supra-second temporal processing may play independent roles in this relation. In the current study, we assessed the development of sub- and supra-second timing across middle childhood and examined how each ability may relate to academic achievement. Child participants (6- to 8-year-olds, n = 111) completed reading and math assessments and a temporal discrimination task that included comparisons in both the sub- and supra-second ranges. Results revealed that younger children performed comparably across the sub- and supra-second ranges, whereas 8-year-olds and adults (n = 72) were relatively better at discriminating durations in the supra-second range. Although discrimination performance in these distinct duration ranges did not uniquely predict math or reading achievement, overall timing abilities were related to math, but not reading, when controlling for age. Together, these data provide evidence for a divergence in timing abilities across sub- and supra-second durations emerging around 8 years of age; however, at least during this stage of development, the relation between children's timing and math achievement is unrelated to this divergence.

Executive processes and timing: Comparing timing with and without reference memory

Temporal perception is influenced by executive function. However, performance on different temporal tasks is often associated with different executive functions. This study examined whether using reference memory during a task influenced how performance was associated with executive resources. Participants completed temporal generalisation and bisection tasks, in their normal versions involving reference memory and in episodic versions without reference memory. Each timing task had two difficulty levels: easy and hard. Correlations between performance on these tasks and measures of executive function (updating, inhibition, task switching, and access to semantic memory) were assessed. Accuracy on the temporal generalisation task was correlated with memory access for all versions of the task. Updating correlated with accuracy only for the reference memory-based version of the task. Temporal bisection performance presented a different pattern of correlations. The bisection point was negatively correlated with inhibition scores, except for the easy episodic condition. The Weber ratio, considered a measure of temporal sensitivity, was negatively correlated with memory access only in the hard episodic condition. Together, the findings suggest that previous models of generalisation and bisection may not accurately reflect the underlying cognitive processes involved in the tasks.

The faster internal clock in ADHD is related to lower processing speed: WISC-IV profile analyses and time estimation tasks facilitate the distinction between real ADHD and pseudo-ADHD

Alterations in temporal processing may represent a primary cause of key symptoms in ADHD. This study is aimed at investigating the nature of time-processing alterations in ADHD and assessing the possible utility of testing time estimation for clinical diagnostics. Retrospective verbal time estimation in the range of several minutes was examined in 50 boys with ADHD and 53 boys with other mental disorders. All participants (age 7-16) attended an outpatient clinic for ADHD diagnostics. The diagnostic assessment included the WISC-IV. Subjects with ADHD made longer and less accurate duration estimates than the clinical control group. The ADHD group showed a specific WISC-IV profile with processing speed deficits. In the ADHD group there was a correlation between processing speed and quality of time estimation that was not observed in the comparison group: higher processing speed indices were related to more accurate duration estimates. The findings provide support for the presence of a faster internal clock in subjects with ADHD and lend further support to the existence of a specific WISC-IV profile in subjects with ADHD. The results show that analyzing WISC-IV profiles and time estimation tasks are useful differential diagnosis tools, particularly when it comes to distinguishing between "real ADHD" and pseudo-ADHD.

Isochronous Sequential Presentation Helps Children Orient Their Attention in Time

Knowing when an event is likely to occur allows attentional resources to be oriented toward that moment in time, enhancing processing of the event. We previously found that children (mean age 11 years) are unable to use endogenous temporal cues to orient attention in time, despite being able to use endogenous spatial cues (arrows) to orient attention in space. Arrow cues, however, may have proved beneficial by engaging exogenous (automatic), as well as endogenous (voluntary), orienting mechanisms. We therefore conducted two studies in which the exogenous properties of visual temporal cues were increased, to examine whether this helped children orient their attention in time. In the first study, the location of an imperative target was predicted by the direction of a left or right spatial arrow cue while its onset was predicted by the relative duration of a short or long temporal cue. To minimize the influence of rhythmic entrainment in the temporal condition, the foreperiod (500 ms/1100 ms) was deliberately chosen so as not to precisely match the duration of the temporal cue (100 ms/400 ms). Targets appeared either at cued locations/onset times (valid trials) or at unexpected locations/onset times (invalid trials). Adults’ response times were significantly slower for invalid versus valid trials, in both spatial and temporal domains. Despite being slowed by invalid spatial cues, children (mean age 10.7 years) were unperturbed by invalid temporal cues, suggesting that these duration-based temporal cues did not help them orient attention in time. In the second study, we enhanced the exogenous properties of temporal cues further, by presenting multiple temporal cues in an isochronous (rhythmic) sequence. Again, to minimize automatic entrainment, target onset did not match the isochronous interval. Children (mean age 11.4 years), as well as adults, were now significantly slowed by invalid cues in both the temporal and spatial dimension. The sequential, as opposed to single, presentation of temporal cues therefore helped children to orient their attention in time. We suggest that the exogenous properties of sequential presentation provide a temporal scaffold that supports the additional attentional and mnemonic requirements of temporal, as compared to spatial, processing.

Distinct developmental trajectories for explicit and implicit timing

Adults and children aged 5 and 8years were given explicit and implicit timing tasks. These tasks were based on the same temporal representation (the temporal interval between two signals), but in the explicit task participants received overt instructions to judge the duration of the interval, whereas in the implicit task they did not receive any temporal instructions and were asked only to press as quickly as possible after the second signal. In addition, participants' cognitive capacities were assessed with different neuropsychological tests. The results showed that temporal variability (i.e., the spread of performance around the reference interval) decreased as a function of age in the explicit task, being higher in the 5-year-olds than in the 8-year-olds and adults. The higher variability in the youngest children was directly linked to their limited cognitive capacity. By contrast, temporal variability in the implicit timing task remained constant across the different age groups and was unrelated to cognitive capacity. Processing of time, therefore, was independent of age in the implicit task but changed with age in the explicit task, thereby demonstrating distinct developmental trajectories for explicit and implicit timing.

Faster is briefer: The symbolic meaning of speed influences time perception

The present study investigates how the symbolic meaning of the stimuli presented for marking time intervals affects perceived duration. Participants were engaged in a time bisection task in which they were first trained with two standard durations, 400 ms and 1600 ms, and then asked to judge if the following temporal intervals were closer to the short or to the long standard. Stimuli were images of vehicles representing speed, with a motorbike representing fastness and a bicycle representing slowness. Results showed that presenting images with different speed meanings affects time perception: an image representing a fast object, the motorbike, leads to shorter perceived time than presenting an image representing a slower object, the bicycle. This finding is attributed to an impact on the memory mechanism involved in the processing of temporal information.

Time knowledge acquisition in children aged 6 to 11 years and its relationship with numerical skills

Acquisition of time knowledge (TK; the correct representation and use of time units) is linked to the development of numerical abilities, but this relationship has not been investigated in children. The current study examined the acquisition of TK and its association with numerical skills. A total of 105 children aged 6 to 11 years were interviewed with our Time Knowledge Questionnaire (TKQ), developed for purposes of this study, and the Zareki-R, a battery for the evaluation of number processing and mental calculation. The TKQ assessed conventional time knowledge (temporal orientation, temporal sequences, relationships between time units, and telling the time on a clock), estimation of longer durations related to birthday and life span, and estimation of the duration of the interview. Time knowledge increased with age, especially from 6 to 8 years, and was strongly linked to numerical skills. Regression analyses showed that four numerical components were implicated in TK: academic knowledge of numbers and number facts (e.g., reading Arabic numerals, mental calculation), number line estimation (e.g., correspondence between a number and a distance), contextual estimation (e.g., many/few leaves on a tree, children in a family), and numerical tasks involving verbal working memory (e.g., comparison of numbers presented orally). Numerical correlations with TK varied according to children's age; subtests based on academic knowledge of numbers, working memory, and number line estimation were linked with TK in the younger children, but only contextual estimation was associated with TK in the older children.

Cognitive abilities required in time judgment depending on the temporal tasks used: A comparison of children and adults

The aim of this study was to examine age-related differences in time judgments during childhood as a function of the temporal task used. Children aged 5 and 8 years, as well as adults, were submitted to 3 temporal tasks (bisection, generalization and reproduction) with short (0.4/0.8 s) and long durations (8/16 s). Furthermore, their cognitive capacities in terms of working memory, attentional control, and processing speed were assessed by a wide battery of neuropsychological tests. The results showed that the age-related differences in time judgment were greater in the reproduction task than in the temporal discrimination tasks. This task was indeed more demanding in terms of working memory and information processing speed. In addition, the bisection task appeared to be easier for children than the generalization task, whereas these 2 tasks were similar for the adults, although the generalization task required more attention to be paid to the processing of durations. Our study thus demonstrates that it is important to understand the different cognitive processes involved in time judgment as a function of the temporal tasks used before venturing to draw conclusions about the development of time perception capabilities.

Children can implicitly, but not voluntarily, direct attention in time

Children are able to use spatial cues to orient their attention to discrete locations in space from around 4 years of age. In contrast, no research has yet investigated the ability of children to use informative cues to voluntarily predict when an event will occur in time. The spatial and temporal attention task was used to determine whether children were able to voluntarily orient their attention in time, as well as in space: symbolic spatial and temporal cues predicted where or when an imperative target would appear. Thirty typically developing children (average age 11 yrs) and 32 adults (average age 27 yrs) took part. Confirming previous findings, adults made use of both spatial and temporal cues to optimise behaviour, and were significantly slower to respond to invalidly cued targets in either space or time. Children were also significantly slowed by invalid spatial cues, demonstrating their use of spatial cues to guide expectations. In contrast, children’s responses were not slowed by invalid temporal cues, suggesting that they were not using the temporal cue to voluntarily orient attention through time. Children, as well as adults, did however demonstrate signs of more implicit forms of temporal expectation: RTs were faster for long versus short cue-target intervals (the variable foreperiod effect) and slower when the preceding trial’s cue-target interval was longer than that on the current trial (sequential effects). Overall, our results suggest that although children implicitly made use of the temporally predictive information carried by the length of the current and previous trial’s cue-target interval, they could not deliberately use symbolic temporal cues to speed responses. The developmental trajectory of the ability to voluntarily use symbolic temporal cues is therefore delayed, relative both to the use of symbolic (arrow) spatial cues, and to the use of implicit temporal information.

The differential contribution of executive functions to temporal generalisation, reproduction and verbal estimation

Evidence from dual-task studies suggests that executive resources are recruited during timing. However, there has been little exploration of whether executive recruitment is universal across temporal tasks, or whether different temporal tasks recruit different executive resources. The current study explored this further by examining how individual differences in updating, switching, inhibition and access affected performance on temporal generalisation, reproduction and verbal estimation tasks. It was found that temporal tasks differentially loaded onto different executive resources. Temporal generalisation performance was related to updating and access ability. Reproduction performance was related to updating, access and switching. Verbal estimation performance was only related to access. The results suggest that executive resources may be recruited when monitoring and maintaining multiple durations in memory at the same time, and when retrieving duration representations from long-term memory. The findings emphasise the need to consider timing behaviour as the product of a wide range of complex, integrated, cognitive systems, rather than as the output of a clock in isolation.