Is the interference between memory processing and timing specific to the use of verbal material?

Increasing load in a memory task performed simultaneously with a timing task shortens perceived time, an effect that has been observed previously with memory tasks using verbal material. The present experiments examine whether two similar memory tasks, one in which verbal material is used and another one in which nonverbal material is used, would produce similar interference effects on concurrent time reproduction. In Experiment 1, the number of nonverbal stimuli (pseudo‐random dot patterns) was manipulated in a memory task performed while a temporal interval to be reproduced was encoded. Reproductions shortened proportionally to the duration of memory processing executed during time estimation. Verbal stimuli (consonants) were used in Experiment 2 in otherwise identical experimental conditions. Effects observed in Experiment 2 were comparable to those obtained in Experiment 1. Taken together, these results support the notion that interference from memory tasks on concurrent time estimation is not determined by the specific type of material processed in memory, but instead by the duration of memory processing.     

Is the interference between memory processing and timing specific to the use of verbal material?

Increasing load in a memory task performed simultaneously with a timing task shortens perceived time, an effect that has been observed previously with memory tasks using verbal material. The present experiments examine whether two similar memory tasks, one in which verbal material is used and another one in which nonverbal material is used, would produce similar interference effects on concurrent time reproduction. In Experiment 1, the number of nonverbal stimuli (pseudo-random dot patterns) was manipulated in a memory task performed while a temporal interval to be reproduced was encoded. Reproductions shortened proportionally to the duration of memory processing executed during time estimation. Verbal stimuli (consonants) were used in Experiment 2 in otherwise identical experimental conditions. Effects observed in Experiment 2 were comparable to those obtained in Experiment 1. Taken together, these results support the notion that interference from memory tasks on concurrent time estimation is not determined by the specific type of material processed in memory, but instead by the duration of memory processing.     

Differential involvement of internal clock and working memory in the production and reproduction of duration: a study on older adults

The present study uses the inter-individual variability in time perception of a group of elderly participants to differentiate the processes underlying time production and time reproduction. Participants performed duration production and reproduction tasks. They were also administered working memory tests and a spontaneous motor tempo task. The findings suggest that duration production and duration reproduction involve different mechanisms. Correlational analyses revealed a double dissociation: production was only correlated with spontaneous motor tempo and reproduction only with working memory measures. These findings suggest that the internal clock rate modulates the production of duration and that reproduced duration varies according to working memory capacities.     

工作记忆的存储时间及目标时距对时间知觉的影响

本研究操作记忆信息与计时开始之间的时间间隔（ISI）和目标时距,探讨工作记忆影响时间判断的灵活性。被试首先记忆一个客体,然后在每个trial的最后判断测试刺激是否与记忆项相同;在延迟阶段,被试完成时间判断任务,即判断相继出现的两个刺激的时距哪个更长（或更短）。时间任务中的一个刺激与记忆内容完全相同,相应的另一个刺激与记忆内容在形状和颜色上都不同。重复条件下,被试忽略第一个刺激,仅完成时间判断任务。结果发现,时间间隔（ISI）短时,记忆匹配条件下的准确率更高,匹配刺激延长了知觉的时间;但随着时间间隔的增加,工作记忆匹配对时间判断的影响降低甚至消失。并且,长或短ISI,记忆任务或重复条件下,目标时距长时,记忆匹配反而缩短了知觉的时间。研究说明工作记忆对时间判断的影响是灵活的,受到注意或工作记忆等高级认知系统的调控。     

Time perception and attention: The effects of prospective versus retrospective paradigms and task demands on perceived duration

This research was designed to compare time judgments obtained under prospective conditions (in which subjects are instructed to attend to time) and retrospective conditions (in which subjects are unaware that they will be required to judge time). In Experiment 1, subjects prospectively or retrospectively judged the duration of intervals spent performing a perceptual-motor task at different levels of difficulty. The results showed that subjects tested under both research paradigms tended to give increasingly shorter and/or more inaccurate time judgments with increases in nontemporal task demands. Experiment 2 was designed to test the effects of attentional deployment on perceived time by comparing prospective and retrospective judgments under control, selective attention, and divided attention conditions. Both types of time judgments became increasingly inaccurate as attention was more broadly deployed. The results of these experiments are consistent with an attentional allocation model, and they suggest that nontemporal task demands disrupt or interfere with timing in both prospective and retrospective situations.     

Children's time production for concurrent nontemporal motor tasks

An internal clock model has often been used to explain disruptions in timing production that occur when temporal and nontemporal tasks are performed simultaneously. In this study, participants' ability to walk 8 m in 8 sec. while executing various secondary concurrent nontemporal tasks was assessed for 16 children enrolled in sports at school. Children participated in six trials under five randomized task conditions involving different coordinative and cognitive workloads. The duration of timing production increased as the attention requirements or cognitive demands placed upon the completion of the task increased. However, participants also showed learning of timing over the six trials. Significant differences were found between the timing task and the concurrent nontemporal tasks depending on the difficulty and cognitive load of the secondary tasks. Results are discussed using attention models of time estimation and production.     

Sense of Time and Executive Functioning in Children and Adults

A number of patient studies suggest that impairments in frontal lobe functions are associated with disorders in temporal information processing. One implication of these findings is that subjective experience of time should be related to executive functions regardless of etiology. In two experiments, we examined sense of time in relation to components of executive functioning in healthy children and adults. In Experiment 1, children between 8 to 12 years completed six experimental tasks that tapped three components of executive functioning: inhibition, updating, and mental shifting. Sense of time was examined in a duration judgment task in which participants reproduced stimulus durations between 4 to 32 s. In Experiment 2, adult participants completed the time reproduction task under varying concurrent task demands. Both experiments showed selective effects in that time reproduction errors were related to the inhibition and updating, but not to the shifting, components of executive functioning. However, the observed effects were modulated by task demands and age-related differences in cognitive competence. We conclude that individual differences in executive functioning are only weakly related to time reproduction performance in healthy children and adults.     

The roles of the central executive and visuospatial storage in mental arithmetic: A comparison across strategies

Previous research has demonstrated that working memory plays an important role in arithmetic. Different arithmetical strategies rely on working memory to different extents—for example, verbal working memory has been found to be more important for procedural strategies, such as counting and decomposition, than for retrieval strategies. Surprisingly, given the close connection between spatial and mathematical skills, the role of visuospatial working memory has received less attention and is poorly understood. This study used a dual-task methodology to investigate the impact of a dynamic spatial n-back task (Experiment 1) and tasks loading the visuospatial sketchpad and central executive (Experiment 2) on adults' use of counting, decomposition, and direct retrieval strategies for addition. While Experiment 1 suggested that visuospatial working memory plays an important role in arithmetic, especially when counting, the results of Experiment 2 suggested this was primarily due to the domain-general executive demands of the n-back task. Taken together, these results suggest that maintaining visuospatial information in mind is required when adults solve addition arithmetic problems by any strategy but the role of domain-general executive resources is much greater than that of the visuospatial sketchpad.     

数字加工任务影响时距知觉的数字效应

本研究采用复制时距和数字加工双任务,探讨数字大小影响时距知觉的机制。实验首先呈现不同时距的圆点,然后让被试按键复制圆点呈现的时距,与此同时,对屏幕上出现的数字进行命名(实验1)、奇偶数判断(实验2)、大小判断(实验3)。实验结果发现对数字进行奇偶数判断时,数字大小对时距知觉没有影响;进行数字命名和大小判断任务时,数字大小对时距知觉都产生了影响,并且时距不同,数字大小对时距知觉的影响也不同。该结果表明时距知觉的数字效应与数字加工任务和时距长短有关,呈现出动态变化的过程。     

Duration estimation and the phonological loop: Articulatory suppression and irrelevant sounds

Clock-based theories of time estimation propose that clock pulses are accumulated in working memory. Although these theories do not constrain the form of the memory trace, evidence reported in the literature suggests that active manipulation of a verbal trace may be involved. Four experiments are reported in which participants reproduced or verbally estimated short durations (up to a few seconds) either in a single-task condition or in a condition with a phonological load. Experiments 1, 2 and 4 showed that both interval reproduction and verbal estimation were impaired under concurrent articulatory suppression in comparison to a timing only control condition. Neither irrelevant speech (Experiments 1-3) nor irrelevant tones and music (Experiment 3) impaired timing performance. These findings are taken to show that time estimation is mediated by phonological working memory and the involvement of an active articulatory rehearsal process.     

The role of metacognition in prospective memory: Anticipated task demands influence attention allocation strategies

The present study investigates how individuals distribute their attentional resources between a prospective memory task and an ongoing task. Therefore, metacognitive expectations about the attentional demands of the prospective-memory task were manipulated while the factual demands were held constant. In Experiments 1a and 1b, we found attentional costs from a prospective-memory task with low factual demands to be significantly reduced when information about the low to-be-expected demands were provided, while prospective-memory performance remained largely unaffected. In Experiment 2, attentional monitoring in a more demanding prospective-memory task also varied with information about the to-be-expected demands (high vs. low) and again there were no equivalent changes in prospective-memory performance. These findings suggest that attention–allocation strategies of prospective memory rely on metacognitive expectations about prospective-memory task demands. Furthermore, the results suggest that attentional monitoring is only functional for prospective memory to the extent to which anticipated task demands reflect objective task demands.     

The relativity of time perception produced by facial emotion stimuli

We systematically examined the impact of emotional stimuli on time perception in a temporal reproduction paradigm where participants reproduced the duration of a facial emotion stimulus using an oval-shape stimulus or vice versa. Experiment 1 asked participants to reproduce the duration of an angry face (or the oval) presented for 2,000 ms. Experiment 2 included a range of emotional expressions (happy, sad, angry, and neutral faces as well as the oval stimulus) presented for different durations (500, 1,500, and 2,000 ms). We found that participants over-reproduced the durations of happy and sad faces using the oval stimulus. By contrast, there was a trend of under-reproduction when the duration of the oval stimulus was reproduced using the angry face. We suggest that increased attention to a facial emotion produces the relativity of time perception.     

时距估计年龄差异的认知机制

采用双任务的实验范式,通过对（5s、13s和26s）三个目标时距的产生法和复制法的结果来探讨时距估计年龄差异的认知机制。实验结果表明,在不同目标时距和不同的估计方法上均存在显著的年龄效应。年老被试在产生法上比年轻被试显著高估时距,存在非时间任务和年龄的交互作用,随着任务难度的增加年老被试会比年轻被试产生更长的时距。而在复制法上年老被试比年轻被试显著低估时距,但是只有在长时距条件下（26s）存在非时间任务和年龄的交互作用。本研究结果表明年老被试在产生法上对时距的高估可能与内部时钟减慢和注意资源减少有关,而在复制法上对时距的低估可能反映注意资源的减少。此外,对于长时距的时间复制,情节记忆的损伤也是导致时距估计年龄差异的一个可能原因。     

Strategic and automatic effects of visual working memory on attention in visual search

Previous research indicates that visual attention can be automatically captured by sensory inputs that match the contents of visual working memory. However, Woodman and Luck (2007) showed that information in working memory can be used flexibly as a template for either selection or rejection according to task demands. We report two experiments that extend their work. Participants performed a visual search task while maintaining items in visual working memory. Memory items were presented for either a short or long exposure duration immediately prior to the search task. Memory was tested by a change-detection task immediately afterwards. On a random half of trials items in memory matched either one distractor in the search task (Experiment 1) or three (Experiment 2). The main result was that matching distractors speeded or slowed target detection depending on whether memory items were presented for a long or short duration. These effects were more in evidence with three matching distractors than one. We conclude that the influence of visual working memory on visual search is indeed flexible but is not solely a function of task demands. Our results suggest that attentional capture by perceptual inputs matching information in visual working memory involves a fast automatic process that can be overridden by a slower top-down process of attentional avoidance.     

Contrasting task demands alter the perceived duration of brief time intervals

Four experiments were performed to assess the effects of task differences on duration judgments. Experiments 1 and 2 used the method of reproduction in prospective, within-subjects designs; their results supported previous research on the effects of task difficulty. Both experiments, using tasks that varied along somewhat different dimensions, found that subjects provided reproduction values that varied inversely with task difficulty. That is, while subjects tended to underreproduce across all tasks, the more difficult the task performed during the target interval, the greater the extent of the under-reproduction. Experiments 3 and 4 used a modification of the reproduction method by placing demands upon the subjects during both the target interval and the reproduction phase of each trial; they demonstrated that the greater the degree of contrast between demands made by the task performed during the target interval and those made during reproduction, the less accurate the duration reproduction. The results are discussed in terms of the contextual and resource allocation models of duration estimation.     

Motor creativity: the roles of attention breadth and working memory in a divergent doing task

We evaluated the dual-pathway model to creativity in a motor context. The model describes separate flexibility and persistence pathways that are affected differently by breadth of attention and working memory. Motor creativity was tested using a divergent doing task. In Experiment 1 participants performed the divergent doing task after attention was broadened, narrowed or not manipulated. In Experiment 2, the divergent doing task was performed with a low or high working memory load. We found that a broad attention increased flexibility but not persistence. Also originality was unaffected. Taxing working memory did not affect persistence, flexibility or originality. The results provide partial support for the dual-pathway model in motor creativity. Discusion focusses on increased demands for the appropriatness of a solution in divergent doing relative to divergent thinking and to degree to which this implies a more general shortcoming of the dual-pathway model.     

The relationship between the number of presented stimuli and prospective duration estimates: The effect of concurrent task activity

The attention/distraction models of prospective time estimation predict either a negative relationship or an independence between duration estimates and the number of stimulus events presented during the time period, but not a positive relationship. Two experiments examined this relationship under prospective conditions. Lists of words were presented during a 60-sec time period at either a fast or a slow rate. Subjects either passively viewed the words or actively responded by performing either a graphemic or a semantic classification task on each word. To measure subjective duration, the method of magnitude estimation was used in Experiment 1 and the method of reproduction was used in Experiment 2. Time estimates were independent of the number of presented words in the passive viewing condition, and negatively related in the classification task conditions. Furthermore, the two classification tasks had similar effects on time estimates. These findings are consistent with the attentional models of prospective timing, and they question the robustness of earlier findings of a positive relationship between time estimates of moderately long intervals and the number of presented stimuli under conditions of minimal processing of the interval events.     

Age Differences in Multiple Outcome Measures of Time-Based Prospective Memory

ABSTRACT

This study examined time-based prospective memory performance in relation to age, monitoring strategy, response accuracy, and dual-task demands. Young, middle-aged and older adults (N?=?115) completed a prospective memory task, in which they indicated the passing of time every 5 min while listening to a short story (low task demands) or completing a series of cognitive tasks (high task demands). Young and older adults showed similar patterns of monitoring behavior, with low rates of clock checking during the early phase of each 5-min interval, followed by linearly accelerating monitoring functions. However, to obtain the same level of prospective memory performance older adults needed more frequent clock checks than young adults. Furthermore, older adults' compensatory monitoring strategy was associated with an additional cost in primary task performance. Finally, increased primary task demands shifted age differences in prospective memory from monitoring frequency to response accuracy. These findings suggest that goal-directed behavior requires efficient task coordination and resource allocation, and that age-related differences in time-based prospective memory should be evaluated by using multiple outcome measures.     

Spatial working memory load affects counting but not subitizing in enumeration

The present study investigated whether subitizing reflects capacity limitations associated with two types of working memory tasks. Under a dual-task situation, participants performed an enumeration task in conjunction with either a spatial (Experiment 1) or a nonspatial visual (Experiment 2) working memory task. Experiment 1 showed that spatial working memory load affected the slope of a counting function but did not affect subitizing performance or subitizing range. Experiment 2 showed that nonspatial visual working memory load affected neither enumeration efficiency nor subitizing range. Furthermore, in both spatial and nonspatial memory tasks, neither subitizing efficiency nor subitizing range was affected by amount of imposed memory load. In all the experiments, working memory load failed to influence slope, subitizing range, or overall reaction time. These findings suggest that subitizing is performed without either spatial or nonspatial working memory. A possible mechanism of subitizing with independent capacity of working memory is discussed.     

ERP predictors of individual performance on a prospective temporal reproduction task

The present study aimed at investigating whether different aspects of performance on a prospective reproduction task with a standard duration of 2 s had different antecedents in the event-related potentials (ERPs) accompanying standard presentations and reproduced intervals. On each trial, first the standard duration was presented as an empty auditory interval. After a short delay, participants reproduced this interval by means of two button presses defining onset and offset of the reproduced interval. About 25 participants were divided into groups of poor and good time estimators, once based on the coefficient of variation of their reproduced durations, and once based on the absolute error score. Interestingly, for both performance measures differences between participants were accompanied by ERP differences during standard presentations rather than reproduction itself. While larger P300 amplitudes evoked by standard interval offset predicted good reproduction performance in terms of a small coefficient of variation, small absolute error scores were accompanied by larger fronto-central negative slow wave during standard presentations. The results suggest an important role of attention to both the critical events that delimit the to-be-estimated temporal intervals, and to the passing of time between these events.