Knowing which day of the week it is: temporal structure and dynamics of memory

The complementary role of static and dynamic information used when one needs to be located in time was studied. Static information refers to temporal knowledge about days of the week, and dynamic information reflects a sense of time, taking into account the present, the near past, and the future. Each day of an actual 7-day wk., 699 women and 620 men were asked to provide a "right" or "wrong" response to a statement such as "Today is X," where X was the name of one of the seven days of the week. Analysis suggested use of a structured temporal representation of the week: the weekend, a landmark, had an anchoring role. Also the dynamics of the content of working memory were indicated. The active "temporal window" participants hold in mind seems directed more towards the future than the past. Results are discussed within the more general context of time management.     

Reconstructive memory in the dating of personal and public news events

Two experiments investigated memory for the dates of events selected and recorded by subjects in diaries. In Experiment 1, personal events and public news events were compared, with retention time varying from 1 week up to 9 months. It was found that the day of the week was more accurately identified for personal events than for news events, that day-of-the-week (DOW) accuracy did not decrease with increasing retention time, and that memory of the personal context of both event types was more important for DOW accuracy than was memory of the core of the events. These results support our view that memory of the day of the week is mainly reconstructed by reference to a temporal week schema based on personal experiences, and that the relation of news events to the week schema is mediated by memory of personal context. The distribution of DOW errors was modeled as the outcome of a process of guessing constrained by subdivisions of the week schema, without assuming any special temporal memory trace. In Experiment 2, the model was shown to fit independently collected data from a different subject pool and country equally well.     

Individual differences in entrainment of mood to the weekly calendar

This study addressed two questions: Do daily fluctuations in mood exhibit a 7-day (circaseptum) cycle, and are there reliable individual differences in how entrained people's moods are to such a weekly cycle? Spectral analysis of daily mood over 84 occasions revealed a strong weekly rhythm in the temporal organization of mood in a sample of 74 undergraduates. A sine wave with a period of 7 days accounted for 40% of the variance in the daily mood data. Individual differences were also found in how entrained subjects' moods were to this weekly rhythm. We predicted that extraverts (compared with introverts) should be less entrained to a weekly cycle. Results suggest that the novelty- and sensation-seeking behavior of extraverts most likely serves to lessen the cyclical predictability of their day-to-day moods. The origin and psychological meaning of the 7-day week are discussed.     

A long time ago in a galaxy far,far away: How temporal are episodic contents?

A prominent feature of mental event (i.e. ‘episodic’) simulations is their temporal orientation: human adults can generate episodic representations directed towards the past or the future. Here, we investigated how the temporal orientation of imagined events relates to the contents of these events. Is there something intrinsically temporal about episodic contents? Or does their temporality rely on a distinct set of representations? In three experiments (N = 360), we asked participants to generate and later recall a series of imagined events differing in (1) location, (2) time of day, (3) temporal orientation, and (4) weekday. We then tested to what extent successful recall of episodic content (i.e. (1) and (2)) would predict recall of temporality and/or weekday information. Results showed that recall of temporal orientation was only weakly predicted by recall of episodic contents. Nonetheless, temporal orientation was more strongly predicted by content recall than weekday recall. This finding suggests that episodic simulations are unlikely to be intrinsically temporal in nature. Instead, similar to other forms of temporal information, temporal orientation might be determined from such contents by reconstructive post-retrieval processes. These results have implications for how the human ability to ‘mentally travel’ in time is cognitively implemented.     

Using a calendar in event dating

Three experiments examined Thompson's reconstructive account for estimating the temporal location of an event. Thompson's day‐of‐week (DOW) model suggests that people know the DOW because diary studies have consistently produced dating errors at 7‐day intervals (e.g. 0, 7, 14, 21, etc.). This study determined whether this DOW effect was produced by a calendar. It also examined whether time estimations were primarily reconstructed. A calendar improved both date and DOW estimates, but neither estimate depended on the use of a calendar. In addition, both date and DOW estimates were primarily reconstructed, but a large portion of DOW estimates were reproduced. Therefore, the argument was made that theories explaining memory for temporal location should account for both reproductive and reconstructive processes. Copyright © 2001 John Wiley & Sons, Ltd.     

Children's memory for complex autobiographical events: does spacing of repeated instances matter?

Often, when children testify in court they do so as victims of a repeated offence and must report details of an instance of the offence. One factor that may influence children's ability to succeed in this task concerns the temporal distance between presentations of the repeated event. Indeed, there is a substantial amount of literature on the "spacing effect" that suggests this may be the case. In the current research, we examined the effect of temporal spacing on memory reports for complex autobiographical events. Children participated in one or four play sessions presented at different intervals. Later, children were suggestively questioned, and then participated in a memory test. Superior recall of distributed events (a spacing effect) was found when the delay to test was 1 day (Experiment 1) but there was little evidence for a spacing effect when the delay was 1 week (Experiment 2). Implications for understanding children's recall of repeated autobiographical events are discussed.     

Young Children's Memory for the Times of Personal Past Events

Remembering the temporal information associated with personal past events is critical for autobiographical memory, yet we know relatively little about the development of this capacity. In the present research, we investigated temporal memory for naturally occurring personal events in 4-, 6-, and 8-year-old children. Parents recorded unique events in which their children participated during a 4-month period. At test, children made relative recency judgments and estimated the time of each event using conventional time scales (time of day, day of week, month of year, and season). Children also were asked to provide justifications for their time-scale judgments. Six- and 8-year-olds, but not 4-year-olds, accurately judged the order of two distinct events. There were age-related improvements in children's estimation of the time of events using conventional time scales. Older children provided more justifications for their time-scale judgments compared with younger children. Relations between correct responding on the time-scale judgments and provision of meaningful justifications suggest that children may use that information to reconstruct the times associated with past events. The findings can be used to chart a developmental trajectory of performance in temporal memory for personal past events and have implications for our understanding of autobiographical memory development.     

Children's memory for complex autobiographical events: Does spacing of repeated instances matter?

Often, when children testify in court they do so as victims of a repeated offence and must report details of an instance of the offence. One factor that may influence children's ability to succeed in this task concerns the temporal distance between presentations of the repeated event. Indeed, there is a substantial amount of literature on the “spacing effect” that suggests this may be the case. In the current research, we examined the effect of temporal spacing on memory reports for complex autobiographical events. Children participated in one or four play sessions presented at different intervals. Later, children were suggestively questioned, and then participated in a memory test. Superior recall of distributed events (a spacing effect) was found when the delay to test was 1?day (Experiment 1) but there was little evidence for a spacing effect when the delay was 1 week (Experiment 2). Implications for understanding children's recall of repeated autobiographical events are discussed.     

Mental reinstatement of the misinformation context and the misinformation effect in children and adults

The present study investigated the effects of mental reinstatement of the context in which misleading information about an event was presented on later recognition memory for the event. Five‐year‐olds, 7‐year‐olds and adults were shown a short video depicting a children's adventure and were asked a set of misleading questions to introduce misinformation one week later. Before the recognition memory test was administered another week later, half of the participants were given instructions to mentally reinstate the context of the misleading interview. Memory was assessed with a set of forced‐choice recognition questions once in the misleading interview context and for the children a second time at home one week later. When participants were instructed to mentally reinstate the context of the misleading interview prior to the recognition test, false memory reports occurred more often for adults than for children and had a stronger impact on peripheral information than on central information for both 7‐year‐olds and adults. When 5‐ and 7‐year‐olds were tested at home, false memory reports decreased. Thus, reinstating the context of an interview introducing misinformation can reduce the accuracy of memory reports; the context dependence of both accurate and inaccurate memory reports in children and adults is discussed. Copyright © 2003 John Wiley & Sons, Ltd.     

Reports of elapsed time: bounding and rounding processes in estimation

The present article concerns the way temporal information is represented in memory and the processes used in estimating when events occurred. In particular, we examine the sources of bias in reports of the time that has elapsed since a target event occurred. We find that reported times are less than actual times. Evidence is presented that this forward bias is not a result of misrepresentation of elapsed time in memory, but rather reflects two factors that arise in constructing reports from inexact information in memory. One factor is subjects' imposition of an upper boundary on reports, reflecting their notion of what would constitute reasonable answers to the question asked. This boundary truncates the distribution of reports, producing forward bias. The other factor is subjects' use of rounded (prototypic) values; these values, although stated in days, actually represent larger temporal categories (e.g., 14, 21, 30, 60 days ago). The distance between rounded values increases as the temporal categories become larger. Because of decreasing precision in memory and this increase in the distance between rounded values, a broader range of values is rounded down than up, thus producing forward bias.     

EVENT SEGMENTATION

ABSTRACT— One way to understand something is to break it up into parts. New research indicates that segmenting ongoing activity into meaningful events is a core component of perception and that this has consequences for memory and learning. Behavioral and neuroimaging data suggest that event segmentation is automatic and that people spontaneously segment activity into hierarchically organized parts and subparts. This segmentation depends on the bottom-up processing of sensory features such as movement and on the top-down processing of conceptual features such as actors' goals. How people segment activity affects what they remember later; as a result, those who identify appropriate event boundaries during perception tend to remember more and to learn more proficiently.     

Age differences in the perception of hierarchical structure in events

Everyday activities break down into parts and subparts, and appreciating this hierarchical structure is an important component of understanding. In two experiments we found age differences in the ability to perceive hierarchical structure in continuous activity. In both experiments, younger and older adults segmented movies of everyday activities into large and small meaningful events. Older adults’ segmentation deviated more from group norms than did younger adults’ segmentation, and older adults’ segmentation was less hierarchically organized than that of younger adults. Older adults performed less well than younger adults on event memory tasks. In some cases, measures of event segmentation discriminated between those older adults with better and worse memory. These results suggest that the hierarchical encoding of ongoing activity declines with age, and that such encoding may be important for memory.     

Modeling Cyclical Patterns in Daily College Drinking Data with Many Zeroes

Daily college drinking data often have highly skewed distributions with many zeroes and a rising and falling pattern of use across the week. Alcohol researchers have typically relied on statistical models with dummy variables for either the weekend or all days of the week to handle weekly patterns of use. However, weekend versus weekday categorizations may be too simplistic and saturated dummy variable models too unwieldy, particularly when covariates of weekly patterns are included. In the present study we evaluate the feasibility of cyclical (sine and cosine) covariates in a multilevel hurdle count model for evaluating daily college alcohol use data. Results showed that the cyclical parameterization provided a more parsimonious approach than multiple dummy variables. The number of drinks when drinking had a smoothly rising and falling pattern that was reasonably approximated by cyclical terms, but a saturated set of dummy variables was a better model for the probability of any drinking. Combining cyclical terms and multilevel hurdle models is a useful addition to the data analyst toolkit when modeling longitudinal drinking with high zero counts. However, drinking patterns were not perfectly sinusoidal in the current application, highlighting the need to consider multiple models and carefully evaluate model fit.     

Temporal interval production and processing in working memory

Short-term memory or working memory has been proposed as a cognitive structure contributing to time estimation. Thus, in a previous experiment, retrieving a stored item during a temporalinterval production lengthened the interval in proportion to the number of items in the memory set. In the present study, this issue was analyzed further by testing whether the proportional lengthening is induced by the load itself (i.e., the number of items) or by comparing the probe with memorized items. In a first experiment, a memory set was maintained during a temporal production, and the comparison of the probe with memorized items was postponed until the end of time production. Varying the number of items in the memory set had no effect on temporal intervals produced during its retention, suggesting that mental comparison was the source of the lengthening of time intervals. In succeeding experiments, tasks requiring processing in working memory but involving no memory load were combined with temporal production. In Experiment 2, increasing the number of syllables in a rhyme-judgment task proportionally lengthened temporal intervals that were produced simultaneously. In Experiment 3, increasing the amount of mental rotation in a task involving visuospatial processing also lengthened simultaneous temporal production. This interference between processing in working memory and time estimation suggests that working memory, defined as a work space for active processing of current information, contributes to time estimation.     

Relationships between time of day,day of the week,and positive mood: Exploring the role of the mood measure

This study examined the relationship between time of day, day of the week, and two measures of positive affect (PA). According to previous research and the circumplex model of affect, one scale was designed to assess the activation component of PA, and the other one measured the pleasantness aspect. Subjects rated their mood three times a day for 7 consecutive days. Consistent with our hypotheses, PA-Pleasantness showed a peak on the weekend, whereas PA-Activation remained stable throughout the week. Regarding time of day, maximum PA-Activation was reached in the afternoon. In contrast, the Pleasantness component of PA increased from morning to evening. Implications of these results as well as other findings concerning the differential content of PA measures are discussed regarding the fact that a certain scale is most appropriate and maximally valid for representing certain aspects of affective experience.We would like to thank two anonymous reviewers and the associate editor, Robert A. Baron, for their constructive comments on an earlier version of this article.     

The role of cuing and organization in children's memory for events

Children's memory for a standardized, hierarchically organized event, making clay, was tested in two experiments. Immediately after participating in this event and again 2 weeks later, children described how they had made the clay. In Experiment 1, action and object cues were presented but only action cues greatly facilitated recall. Children who remade the clay reported more information and also reported more of the actions most central to the goal of the event during delayed recall. In Experiment 2, verbal cues representing two levels in the event hierarchy were presented, but neither aided recall. These and other patterns in the data indicated that, at most, the rudiments of a hierarchical structure had emerged after a single experience. These results were discussed in terms of their implications for the development and organization of event memories.     

When visual search functions look like item recognition functions

Visual search data were collected from six Ss on three target set sizes on each of 30 days. Error level was low, and items assigned to memory sets were nonnested and changed from session tosession. For each S. the same item sometimes required a positive and sometimes a negative response (response inconsistency). Combining data over Ss and over successive 6-day blocks, visual search rates as a function of target set size were found to be linear for each of the five 6-day blocks. The slopes of the above functions (memory search time) did not differ significantly over the final four 6-day blocks, and averaged approximately.500 sec per six-character item. These results are qualitatively very similar to results obtained from item recognition studies when error level, memory set structure, degree of response’_ consistency, and practice are handled in the same way in that task. The significantly lower slope obtained on the first 6-day block is shown to be consistent with a speed-accuracy trade off interpretation when error rate is expressed per unit of processing time (percent errors/set size). Over the final three 6-day blocks, where all important parameters ofthe data were highly stable, the intercepts of the memory search functions were found to closely approximate zero, averaging .0068 sec. From this finding, along with the finding that the memory search functions are linear, it is inferred that visual search time is determined entirely by memory search time, or by memory search time and other processes which increase linearly with set size, under the conditions of this experiment. The estimate of memory search time (approximately 83 msec/character) obtained using this visual search procedure is much slower than that obtained using the item recognition procedure (approximately 35\2-40 msec/character). An explanation for this difference is proposed.     

Children's Representation and Imitation of Events: How Goal Organization Influences 3‐Year‐Old Children's Memory for Action Sequences

Children's imitation of adults plays a prominent role in human cognitive development. However, few studies have investigated how children represent the complex structure of observed actions which underlies their imitation. We integrate theories of action segmentation, memory, and imitation to investigate whether children's event representation is organized according to veridical serial order or a higher level goal structure. Children were randomly assigned to learn novel event sequences either through interactive hands‐on experience (Study 1) or via storybook (Study 2). Results demonstrate that children's representation of observed actions is organized according to higher level goals, even at the cost of representing the veridical temporal ordering of the sequence. We argue that prioritizing goal structure enhances event memory, and that this mental organization is a key mechanism of social‐cognitive development in real‐world, dynamic environments. It supports cultural learning and imitation in ecologically valid settings when social agents are multitasking and not demonstrating one isolated goal at a time.     

The Role of Language in Temporal Cognition in 6- to 10-Year-Old Children

The ability to recognize temporal patterns and position events in time emerges during the preschool years and is refined in middle childhood. This study explored individual differences in temporal cognition in relation to verbal and nonverbal abilities. Children (30 boys, 32 girls; M_age = 8;2, age range = 6;0?10;8) completed 3 temporal-cognition tasks measuring estimation of temporal distance (how far events are from the present), knowledge of conventional times of events (specific days or months of events), and flexibility in using the calendar system (arranging nonconsecutive months in order), along with assessments of nonverbal intelligence, verbal short-term memory, visual-spatial working memory, receptive vocabulary, receptive grammar, and reading mastery. Controlling for age, performance across temporal-cognition tasks correlated with language abilities; nonverbal abilities accounted for little to no additional variance. The findings link language skills with the acquisition of conventional time patterns; such patterns developed alongside the ability to gauge distances of events in the past or future and form an organized timeline.