Effect of task length on remembered and predicted duration

Vierordt’s (1868) law states that when estimating the duration of a previous task, people overestimate short durations and underestimate long ones. We examine whether this same pattern holds for remembered and predicted duration for tasks lasting between 1 and 15 min. In support of Vierordt’s law and its extension to future duration estimates, task duration tended to be overestimated for short tasks (less than 2 min) and underestimated for long tasks for both remembered and predicted duration.     

A sham drug improves a demanding prospective memory task

Every day, people rely on prospective memory—our ability to remember to perform a future action—to carry out myriad tasks. We examined how a sham cognitive enhancing drug might improve people's performance on a prospective memory task. We gave some people (but not others) the sham drug, and asked everyone to perform a high-effort prospective memory task. People who received the sham drug performed better on the prospective memory task. They also took longer to perform their ongoing task, suggesting that they increased their effortful monitoring. These results fit with research showing that suggestions can lead people to increase cognitive effort and increase memory performance.     

A sham drug improves a demanding prospective memory task

Every day, people rely on prospective memory--our ability to remember to perform a future action--to carry out myriad tasks. We examined how a sham cognitive enhancing drug might improve people's performance on a prospective memory task. We gave some people (but not others) the sham drug, and asked everyone to perform a high-effort prospective memory task. People who received the sham drug performed better on the prospective memory task. They also took longer to perform their ongoing task, suggesting that they increased their effortful monitoring. These results fit with research showing that suggestions can lead people to increase cognitive effort and increase memory performance.     

Bias in memory predicts bias in estimation of future task duration

Both anecdotal accounts and experimental evidence suggest that people underestimate how long it will take them to complete future tasks. A possible reason for this tendency is that people remember tasks as taking less time than they actually did, with these biased memories causing a corresponding bias in prediction. Two experiments were performed to determine whether or not a systematic bias in memory could explain a similar systematic bias in prediction. In support, it was found that (1) the tendency to underestimate future duration disappears when the task is novel, (2) there is similar bias in estimation of both past and future durations, and (3) variables that affect memory of duration, such as level of experience with the task and duration of delay before estimation, affect prediction of duration in the same way. It appears that, at least in part, people underestimate future event duration because they underestimate past event duration.     

Measuring consciousness: task accuracy and awareness as sigmoid functions of stimulus duration

When consciousness is examined using subjective ratings, the extent to which processing is conscious or unconscious is often estimated by calculating task performance at the subjective threshold or by calculating the correlation between accuracy and awareness. However, both these methods have certain limitations. In the present article, we propose describing task accuracy and awareness as functions of stimulus intensity (thus obtaining an accuracy and an awareness curve) as suggested by Koch and Preuschoff (2007). The estimated lag between the curves describes how much stimulus intensity must increase for awareness to change proportionally as much as accuracy and the slopes of the curves are used to assess how fast accuracy and awareness increases and whether awareness is dichotomous. The method is successfully employed to assess consciousness characteristics on data from four different awareness scales.     

3D-Multiple Object Tracking training task improves passing decision-making accuracy in soccer players

ObjectivesThe ability to perform a context-free 3-dimensional multiple object tracking (3D-MOT) task has been highly related to athletic performance. In the present study, we assessed the transferability of a perceptual-cognitive 3D-MOT training from a laboratory setting to a soccer field, a sport in which the capacity to correctly read the dynamic visual scene is a prerequisite to performance.DesignThroughout pre- and post-training sessions, we looked at three essential skills (passing, dribbling, shooting) that are used to gain the upper hand over the opponent.MethodWe recorded decision-making accuracy during small-sided games in university-level soccer players (n = 23) before and after a training protocol. Experimental (n = 9) and active control (n = 7) groups were respectively trained during 10 sessions of 3D-MOT or 3D soccer videos. A passive control group (n = 7) did not received any particular training or instructions.ResultsDecision-making accuracy in passing, but not in dribbling and shooting, between pre- and post-sessions was superior for the 3D-MOT trained group compared to control groups. This result was correlated with the players' subjective decision-making accuracy, rated after pre- and post-sessions through a visual analogue scale questionnaire.ConclusionsTo our knowledge, this study represents the first evidence in which a non-contextual, perceptual-cognitive training exercise has a transfer effect onto the field in athletes.     

Intrahippocampal insulin improves memory in a passive-avoidance task in male wistar rats

The main impacts of insulin favor the peripheral organs. Although it functions as a neuropeptide, insulin possesses also some central effects. The aim of this study was to determine the effect of intrahippocampal infusion of insulin on passive avoidance learning in healthy male rats. Thirty male wistar rats were divided into three groups (n=10 each). The experimental group had posttraining insulin infusion into the CA1 region of dorsal hippocampus, after which they were compared with sham (saline) and control (intact) groups. Insulin treated animals had greater latency to enter the dark compartment in compare with saline treated (p=0.023) or control groups (p=0.017). Upon our results, we concluded that intrahippocampal injections of insulin may enhance memory for a simple learning task which supports the concept that insulin possibly plays an endogenous role in memory formation.     

Temporal concepts and predicted duration judgments

The present research investigated whether certain conceptualizations of time influence the planning fallacy or the tendency to underestimate predicted task durations. In Experiment 1, participants were presented with one of three types of primes (video, linguistic, video + linguistic) that reflected either an ego or time motion perspective (i.e. an individual moving through time vs. time moving toward an individual). Afterwards, all participants predicted the amount of time required to sort and shelve a stack of journals before actually completing the task. The results showed that across all priming conditions, subjects in the ego motion condition underestimated to a greater extent than those in the time motion condition. Experiment 2 replicated this effect and also found that underestimations are reduced when the implied duration of the experimental session is short vs. long. As a set, these findings have relevant theoretical implications and suggest some potential de-biasing techniques.     

Increasing distractor strength improves accuracy

Attention enhances task-relevant signals while filtering task-irrelevant signals; however, this selection process is not perfect. It is generally assumed that the stronger the irrelevant signal, the more strongly performance is disrupted. The effect of irrelevant coherent motion signals on performance on a color-discrimination task was systematically examined. Motion direction was either congruent or incongruent with response selection. Performance was most impaired when motion signal strength was just above perceptual threshold and improved when the motion signal strength increased. These results suggest that distractors of higher strength increase attentional modulation and are filtered before they interfere with task performance.     

False memory in a short-term memory task

The Deese/Roediger-McDermott (DRM; Roediger & McDermott, 1995) paradigm reliably elicits false memories for critical nonpresented words in recognition tasks. The present studies used a Sternberg (1966) task with DRM lists to determine whether false memories occur in short-term memory tasks and to assess the contribution of latency data in the measurement of false memories. Subjects studied three, five, or seven items from DRM lists and responded to a single probe (studied or nonstudied). In both experiments, critical lures were falsely recognized more often than nonpresented weak associates. Latency data indicated that correct rejections of critical lures were slower than correct rejections of weakly related items at all set sizes. False alarms to critical lures were slower than hits to list items. Latency data can distinguish veridical and false memories in a short-term memory task. Results are discussed in terms of activation-monitoring models of false memory.     

Improving accuracy in an error detection task via task sequence

The intent of this study was to determine whether performance on an error detection task and a series of cognitive search and memory tasks would be affected if performed serially. Fifty-six participants were assigned into two experimental groups, defined by whether they performed the error detection task or the cognitive tasks first. Measures of hit rates and false alarms were taken for the error detection task, and the perceived workload of both tasks was measured immediately following completion. In the group that did the cognitive tasks first, a significant relationship between perceptions of mental demand on the cognitive tasks and subsequent performance on the error detection task was found. Also, false alarms in error detection were correlated with perceptions of time pressure and frustration measured after the error detection task. These results suggest that a mentally demanding initial task may facilitate performance in a subsequent cognitively-based task. Parts of this paper were presented at the American Psychological Society's annual convention in Atlanta, GA in June 2003. The author thanks Abbie Woodruff and Brandon Corbin for their work on the original presentation and their help in data collection, and Blaine Browne for helpful editorial comments.     

Working memory training improves visual short-term memory capacity

Since antiquity, philosophers, theologians, and scientists have been interested in human memory. However, researchers today are still working to understand the capabilities, boundaries, and architecture. While the storage capabilities of long-term memory are seemingly unlimited (Bahrick, J Exp Psychol 113:1–2, 1984), working memory, or the ability to maintain and manipulate information held in memory, seems to have stringent capacity limits (e.g., Cowan, Behav Brain Sci 24:87–185, 2001). Individual differences, however, do exist and these differences can often predict performance on a wide variety of tasks (cf. Engle What is working-memory capacity? 297–314, 2001). Recently, researchers have promoted the enticing possibility that simple behavioral training can expand the limits of working memory which indeed may also lead to improvements on other cognitive processes as well (cf. Morrison and Chein, Psychol Bull Rev 18:46–60 2011). However, initial investigations across a wide variety of cognitive functions have produced mixed results regarding the transferability of training-related improvements. Across two experiments, the present research focuses on the benefit of working memory training on visual short-term memory capacity—a cognitive process that has received little attention in the training literature. Data reveal training-related improvement of global measures of visual short-term memory as well as of measures of the independent sub-processes that contribute to capacity (Awh et al., Psychol Sci 18(7):622–628, 2007). These results suggest that the ability to inhibit irrelevant information within and between trials is enhanced via n-back training allowing for selective improvement on untrained tasks. Additionally, we highlight a potential limitation of the standard adaptive training procedure and propose a modified design to ensure variability in the training environment.     

Effects of delay of prospective memory cues in an ongoing task on prospective memory task performance

To address the mixed results reported in previous studies, the present experiments examined forgetting in prospective memory (PM) by manipulating the delay between the PM instructions and cue presentation in event-based PM tasks. PM performance was measured for delays of 2–20 min in Experiment 1 and for delays of approximately 1–10 min in Experiment 2. Experiment 2 included both focal and nonfocal PM tasks, and speed on the ongoing task was measured to examine evidence for monitoring processes across the delays tested. The results suggest that nonfocal PM performance follows a nonlinear forgetting function (i.e., rapid decline for shorter delays and slower decline for longer delays) when tested over delays from 1 to 20 min. No effect of delay was seen for the focal task tested in Experiment 2 from 1 to 10 min. In Experiment 2, ongoing-task costs were also found for the first delay but not for longer delays, suggesting that monitoring was significantly reduced between 1 and 2.5 min of the ongoing-task trials.     

Working memory costs of task switching

Although many accounts of task switching emphasize the importance of working memory as a substantial source of the switch cost, there is a lack of evidence demonstrating that task switching actually places additional demands on working memory. The present study addressed this issue by implementing task switching in continuous complex span tasks with strictly controlled time parameters. A series of 4 experiments demonstrate that recall performance decreased as a function of the number of task switches and that the concurrent load of item maintenance had no influence on task switching. These results indicate that task switching induces a cost on working memory functioning. Implications for theories of task switching, working memory, and resource sharing are addressed.     

Surprising feedback improves later memory

The hypercorrection effect is the finding that high-confidence errors are more likely to be corrected after feedback than are low-confidence errors (Butterfield & Metcalfe, 2001). In two experiments, we explored the idea that the hypercorrection effect results from increased attention to surprising feedback. In Experiment 1, participants were more likely to remember the appearance of the presented feedback when the feedback did not match expectations. In Experiment 2, we replicated this effect using more distinctive sources and also demonstrated the hypercorrection effect in this modified paradigm. Overall, participants better remembered both the surface features and the content of surprising feedback.     

Working memory and sequence learning in the Hebb Digits task: awareness is predicted by individual differences in operation span

We examined the extent to which individual differences contribute to performance in a task considered to index implicit learning, the Hebb Digits task. Although Hebb Digits learning is considered to be equivalent for those with implicit and explicit knowledge of the repeating digit pattern, this study found that participants who developed explicit knowledge showed learning, whereas those without explicit knowledge did not. Additionally, participants who developed explicit knowledge outperformed participants without explicit knowledge on working memory measures, specifically the Automated Operation Span Task total correct score and absolute score. However, no significant differences were found between those who did and who did not develop explicit knowledge on the Hopkins Verbal Learning Task-Revised, which uses delayed recall to index long-term memory. These results suggest that learning and awareness in the Hebb Digits task relies on individual differences in working memory capacity.     

Training in timing improves accuracy in golf

In this experiment, the authors investigated the influence of training in timing on performance accuracy in golf. During pre- and posttesting, 40 participants hit golf balls with 4 different clubs in a golf course simulator. The dependent measure was the distance in feet that the ball ended from the target. Between the pre- and posttest, participants in the experimental condition received 10 hr of timing training with an instrument that was designed to train participants to tap their hands and feet in synchrony with target sounds. The participants in the control condition read literature about how to improve their golf swing. The results indicated that the participants in the experimental condition significantly improved their accuracy relative to the participants in the control condition, who did not show any improvement. We concluded that training in timing leads to improvement in accuracy, and that our results have implications for training in golf as well as other complex motor activities.     

Concurrent task effects on memory retrieval

Previous studies combining continuous free recall with a concurrent task have generally shown that concurrent tasks impose fairly negligible effects on memory retrieval. By contrast, dual-task studies employing either cued recall or semantic retrieval reveal gross memory impairment and suggest that retrieval is delayed by the centrally demanding phase of the concurrent tasks (i.e., response selection). To explore this conflict, subjects performed continuous free recall while carrying out a serial-choice#x2014; response time (RT) task, as in the previous free recall studies. Unlike these previous studies, however, the choice#x2014;RT task utilized arbitrary stimulus#x2014;response mappings in order to increase the proportion of time devoted to the centrally demanding response selection phase. Recall total was reduced significantly, and recall latency was slowed substantially.     

Effects of task duration on sensitivity to sleep deprivation using the multi-attribute task battery

Several factors affect the sensitivity to sleep deprivation in the performance of computerized tests. Two of these are task complexity and duration. Complexity can improve sensitivity by increasing the demands required to complete the task, but it can also decrease sensitivity by improving the subject’s motivation. The effects of task duration are more predictable in that longer tests generally are more susceptible to deprivation effects than shorter ones. The impact of task duration on an interesting, but complex, aviation simulation was examined here. By breaking down data from 30-min multi-attribute task battery administrations into the first, second, and third 10 min of performance, it was shown that tests shorter than 30 min underestimate the impact of sleep loss on performance. This was especially evident in measures of time-out and tracking errors.     

Rate and duration memory of naturalistic sounds

Research has shown that the tempi of familiar songs are remarkably well-remembered with a high degree of accuracy. The goal of the present research was to determine whether this ability generalizes to various types of ecological sounds and, if so, how rate information is encoded into the cognitive system. Across three experiments, participants were familiarized with a set of sounds and later asked to remember the rate of each. Experiment 1 revealed that the inherent rate of sounds is incidentally learned such that subsequent recognition is comparable across both prospective and retrospective paradigms. Experiment 2 confirmed these findings through an adjustment task and further demonstrated that memory for event rate remains highly accurate regardless if attending is initially directed toward a sound's rate and/or pitch qualities. Lastly, Experiment 3 assessed the ability to recognize event rate vs. duration when the two dimensions systematically co-vary with one another and revealed that rate variations influence duration recognition but not vice versa. These overall findings are discussed relative to a framework that emphasizes the role of event structure in time judgment behavior.