The effects of intention and practice on a non-motor duration estimation task

It has already been shown that the intention to reproduce a motor task in the future improves its learning. Here, we tested whether intention had a similar effect on learning to perform a non-motor duration estimation task, and if intention interacted with the amount of practice. Participants learned to estimate and compare two different durations, with or without intending to reproduce this learning in the future, and with two different amounts of practice. The results showed that intention and practice enhanced task learning independently. Moreover, only practice enhanced learning in over-estimation strategy. These finding are discussed with respect to a possible mechanism by which intention and practice might improve the learning of a duration task.     

Language-specific effects on number computation in toddlers

A fundamental question in developmental science is how brains with and without language compute numbers. Measuring young children's verbal reactions in France (Paris) and in England (Oxford), here we show that, although there is a general arithmetic ability for small numbers that is shared by monkeys and preverbal infants, the development of such initial knowledge in humans follows specific performance patterns, depending on what language the children speak.     

Sequential effects in successive ratio estimation

Sequential effects are examined in four successive ratio estimation (RE) experiments. The procedure in successive RE is identical to that for magnitude estimation (ME), but the task in successive RE is to estimate the ratio of the current to the previous sensation magnitude, and not the separate magnitudes of the sensations. A positive stimulus context effect was found in successive RE for several continua, in agreement with results previously found for ME. The residual autocorrelation for successive RE was zero in many cases, but in some cases negative autocorrelation was found, which is in contrast to the positive autocorrelation that is typically found for ME and other magnitude scaling procedures. It is shown that, when the role of perceptual error is recognized, negative autocorrelation is predicted by a classical model of ratio estimation. Some aspects of response bias are also discussed.     

Localizing practice effects in dual-task performance

Practice effects on dual-task processing are of interest in current research because they may reveal the scope and limits of parallel task processing. Here we used onsets of the lateralized readiness potential (LRP), a time marker for the termination of response selection, to assess processing changes after five consecutive dual-task sessions with three stimulus onset asynchronies (SOAs) and priority on Task 1. Practice reduced reaction times in both tasks and the interference between tasks. As indicated by the LRP, the reduction of dual-task costs can be explained most parsimoniously by a shortening of the temporal demands of central bottleneck stages, without assuming parallel processing. However, the LRP also revealed a hitherto unreported early activation over the parietal scalp after practice in the short SOA condition, possibly indicating the isolation of stimulus–response translation from other central processing stages. In addition, further evidence was obtained from the LRP for a late motoric bottleneck, which is robust against practice.     

Localizing practice effects in dual-task performance

Practice effects on dual-task processing are of interest in current research because they may reveal the scope and limits of parallel task processing. Here we used onsets of the lateralized readiness potential (LRP), a time marker for the termination of response selection, to assess processing changes after five consecutive dual-task sessions with three stimulus onset asynchronies (SOAs) and priority on Task 1. Practice reduced reaction times in both tasks and the interference between tasks. As indicated by the LRP, the reduction of dual-task costs can be explained most parsimoniously by a shortening of the temporal demands of central bottleneck stages, without assuming parallel processing. However, the LRP also revealed a hitherto unreported early activation over the parietal scalp after practice in the short SOA condition, possibly indicating the isolation of stimulus-response translation from other central processing stages. In addition, further evidence was obtained from the LRP for a late motoric bottleneck, which is robust against practice.     

Language-specific effects on number computation in toddlers: A European cross-linguistic cartography

A fundamental question in developmental science is how brains with and without language compute numbers. Measuring young children's verbal reactions in Spain and Finland, we show that, although there is a general arithmetic ability for small numbers that is shared by monkeys and preverbal infants, the development of such initial knowledge in humans follows specific performance patterns, depending on what language the children speak (here, Spanish and Finnish). Together with our previous data collected in France and in England, these new results contribute to a European cross-linguistic cartography of the relationships between language and number development.     

An examination of practice effects in recognition

A study of practice effects in recognition performance is reported. In each of two experiments, different conditions of training were followed by a critical final test. In Experiment 1, a yes-no procedure was used on the critical test. During the training phase, some subjects were tested by the same method, either with or without item-by-item feedback, whereas others were given forced. choice tests. No significant changes in recognition accuracy were observed, either during the training trials or on the final test. However, feedback and experience with forced-choice tests both served to increase the bias toward positive responding. In Experiment 2, the forced-choice procedure was used on the critical final test. Either forced. choice tests or yes-no tests were given on the training lists. Again, there were no significant changes in performance. The absence of practice effects is attributed to the difficulty of identifying and implementing test-appropriate strategies.     

Test reliability and practice effects

The purpose of this paper is to develop mathematical formulations of test reliability when the estimation of reliability requires successive observations and these observations are not independent of the process (or act) of measurement. The specific application of concern arises in performance testing where performance varies as a function of practice and where practice accrues as a result of measurement. Repeated measures are experimentally nonindependent in such cases. Formulations for the estimation of reliability are developed for each of two cases. The first of these assumes a linear model for acquisition; the second assumes a nonlinear (quadratic) model. Illustrative data are presented whereby insights may be gained as to the inadequacy of the models.This investigation was supported by research grant (G14437) from National Science Foundation to Oregon Research Institute.The analysis of much of the data referred to in this report was made possible through the facilities of the Western Data Processing Center at the University of California, Los Angeles.     

The effects of interleaved practice

Previous research shows that interleaving rather than blocking practice of different skills (e.g. abcbcacab instead of aaabbbccc) usually improves subsequent test performance. Yet interleaving, but not blocking, ensures that practice of any particular skill is distributed, or spaced, because any two opportunities to practice the same task are not consecutive. Hence, because spaced practice typically improves test performance, the previously observed test benefits of interleaving may be due to spacing rather than interleaving per se. In the experiment reported herein, children practiced four kinds of mathematics problems in an order that was interleaved or blocked, and the degree of spacing was fixed. The interleaving of practice impaired practice session performance yet doubled scores on a test given one day later. An analysis of the errors suggested that interleaving boosted test scores by improving participants' ability to pair each problem with the appropriate procedure. Copyright © 2009 John Wiley & Sons, Ltd.     

Increasing capacity: practice effects in absolute identification

In most of the long history of the study of absolute identification--since Miller's (1956) seminal article--a severe limit on performance has been observed, and this limit has resisted improvement even by extensive practice. In a startling result, Rouder, Morey, Cowan, and Pfaltz (2004) found substantially improved performance with practice in the absolute identification of line lengths, albeit for only 3 participants and in a somewhat atypical paradigm. We investigated the limits of this effect and found that it also occurs in more typical paradigms, is not limited to a few virtuoso participants or due to relative judgment strategies, and generalizes to some (e.g., line inclination and tone frequency) but not other (e.g., tone loudness) dimensions. We also observed, apart from differences between dimensions, 2 unusual aspects of improvement with practice: (a) a positive correlation between initial performance and the effect of practice and (b) a large reduction in a characteristic trial-to-trial decision bias with practice.     

The effects of recent exposure on general-knowledge estimation

Recent exposure to general-information facts creates a tendency to claim that the facts had been known prior to their exposure. In Experiment 1, this "illusory knowledge effect" occurred even when participants did not have to demonstrate their knowledge by recalling part of the fact. In Experiment 2, the effect was found for both true and false facts. These findings suggest that the tendency to claim that recently presented facts had been previously known is caused by their enhanced familiarity. Accounts that would attribute this effect entirely to an underestimation of participants' knowledge of the new facts or to participants' intentional inflation of their prior knowledge states are not supported by these results.     

Repetition and practice effects in a lexical decision task

Ss classified visually presented verbal units into the categories “in your vocabulary” or “not in your vocabulary.” The primary concern of the experiment was to determine if making a prior decision on a given item affects the latency of a subsequent lexical decision for the same item. Words of both high and low frequency showed a systematic reduction in the latency of a lexical decision as a consequence of prior decisions (priming) but did not show any reduction due to nonspecific practice effects. Nonwords showed no priming effect but did show shorter latencies due to nonspecific practice. The results also indicated that many (at least 36) words can be in the primed state simultaneously and that the effect persists for at least 10 min. The general interpretation was that priming produces an alteration in the representation of a word in memory and can facilitate the terminal portion of the memory search process which is assumed to be random.     

Tracking the acquisition of orthographic skills in developing readers: masked priming effects

A masked priming procedure was used to explore developmental changes in the tuning of lexical word recognition processes. Lexical tuning was assessed by examining the degree of masked form priming and used two different types of prime-target lexical similarity: one letter different (e.g., rlay-->PLAY) and transposed letters (e.g., lpay-->PLAY). The performance of skilled adult readers was compared with that of developing readers in Grade 3. The same children were then tested again two years later, when they were in Grade 5. The skilled adult readers showed no form priming, indicating that their recognition mechanisms for these items had become finely tuned. In contrast, the Grade 3 readers showed substantial form priming effects for both measures of lexical similarity. When retested in Grade 5, the developing readers no longer showed significant one letter different priming, but transposed letter priming remained. In general, these results provide evidence for a transition from more broadly tuned to more finely tuned lexical recognition mechanisms and are interpreted in the context of models of word recognition.     

The effects of ongoing activity on time estimation in prospective remembering

Two experiments examined whether time‐based prospective memory performance is influenced by the continuous or discontinuous nature of an ongoing activity. The first experiment demonstrated that prospective memory performance was not influenced by the engagement in continuous or discontinuous ongoing activity. The second experiment demonstrated that a discontinuous ongoing activity negatively affected prospective memory performance when participants had to execute two time‐based tasks for which the retention intervals partially overlapped. The results suggest that when individuals are engaged in multiple time‐based tasks, a general timing disruption occurs, with a proactive interference effect resulting in costs that are detrimental to prospective timing. Copyright © 2009 John Wiley & Sons, Ltd.