Repetition Costs Research Articles

An ERP study of inhibition of non-target languages in trilingual word production

The present study examined the locus where inhibition of non-target languages is exerted during trilingual word production by analyzing the cue-locked and stimulus-locked ERPs respectively in the n-2 language repetition paradigm. During the experiment, Uighur–Chinese–English trilinguals overtly named Arabic digits in one of their three languages according to a visually presented cue while their behavioral and electrophysiological responses were recorded. The behavioral data revealed insignificant n-2 repetition costs. Cue-locked ERPs revealed also only tiny or marginally significant n-2 repetition effects over some midline electrodes. The stimulus-locked ERP data showed a more negative ERP component elicited by the n-2 repetition trials than the n-2 non-repetition trials around 250ms after stimulus onset, but no significant difference in this ERP effect between different languages was found. The results indicate that inhibition of non-target languages occurs at the lemma selection phase rather than the language task schemas phase during trilingual language production.

On the importance of being first: Serial order effects in the interaction between action plans and ongoing actions

When we plan sequences of actions, we must hold some elements of the sequence in working memory (WM) while we execute others. Research shows that execution of an action can be delayed if it partly overlaps (vs. does not overlap) with another action plan maintained in WM (partial repetition cost). However, it is not known whether all features of the action maintained in WM interfere equally with current actions. Most serial models of memory and action assume that interference will be equal, because all action features in the sequence should be activated to an equal degree in parallel; others assume that action features earlier in the sequence will interfere more than those later in the sequence, because earlier features will be more active. Using a partial repetition paradigm, this study examined whether serial position of action features in action sequences maintained in WM have an influence on current actions. Two stimulus events occurred in a sequence, and participants planned and maintained an action sequence to the first event (action A) in WM while executing a speeded response to the second event (action B). Results showed delayed execution of action B when it matched the first feature in the action A sequence (partial repetition cost), but not when it matched the last feature. These findings suggest that serial order is represented in the action plan prior to response execution, consistent with models that assume that serial order is represented by a primacy gradient of parallel feature activation prior to action execution.

Rigorous benchmarking in reasonable time

Experimental evaluation is key to systems research. Because modern systems are complex and non-deterministic, good experimental methodology demands that researchers account for uncertainty. To obtain valid results, they are expected to run many iterations of benchmarks, invoke virtual machines (VMs) several times, or even rebuild VM or benchmark binaries more than once. All this repetition costs time to complete experiments. Currently, many evaluations give up on sufficient repetition or rigorous statistical methods, or even run benchmarks only in training sizes. The results reported often lack proper variation estimates and, when a small difference between two systems is reported, some are simply unreliable. In contrast, we provide a statistically rigorous methodology for repetition and summarising results that makes efficient use of experimentation time. Time efficiency comes from two key observations. First, a given benchmark on a given platform is typically prone to much less non-determinism than the common worst-case of published corner-case studies. Second, repetition is most needed where most uncertainty arises (whether between builds, between executions or between iterations). We capture experimentation cost with a novel mathematical model, which we use to identify the number of repetitions at each level of an experiment necessary and sufficient to obtain a given level of precision. We present our methodology as a cookbook that guides researchers on the number of repetitions they should run to obtain reliable results. We also show how to present results with an effect size confidence interval. As an example, we show how to use our methodology to conduct throughput experiments with the DaCapo and SPEC CPU benchmarks on three recent platforms.

SU-E-T-64: QUART Nonius - Quality Control in Radiation Therapy Without Film

Purpose: Present a cost‐efficient device for the measurement of therapy beam edges as an alternative to the use of conventional, radiochromic or CR films. Methods: The Nonius device consists of a 4 cm ruler located above a radio‐sensitive array of 16 photo‐sensitive detectors. Each detector is 0.4 × 0.4 mm and separated by 2.56 mm. The Nonius' ruler is centered on the edge of the light field and then irradiated. A profile along the radiation field edge is displayed and the position corresponding to 50 % decay is automatically compared with the center of the ruler to determine the deviation of the radiation and light fields. Nonius was irradiated and evaluated using 15MV photons (with a flattening filter), 6–7MV photons FFF (flattening filter free) and 1MV photons (Carbon target) from a linear accelerator. The doses varied between 1 and 10 cGy (1 to 10 monitor units, MU). Results: Nonius is able to measure a useable profile signal with as little as a 2 MU dose. The measured profiles were validated with a conventional diode array. For the case of FFF profiles, the evaluation method should be adapted to determine the edge correctly. The results, including graphs and all data, can be directly printed from the software or stored. Conclusion: The applicability of Nonius for accurately comparing the coincidence of therapy light and radiation fields was investigated and confirmed. The advantages of using this device in place of film is its ability to automatically and objectively evaluate the coincidence of these fields, the reduced time it takes to make and display measurement results, and the elimination of the repetitive costs and other complications incurred when using various types of film. Thus, a simplification of a necessary and required quality control procedure for linear accelerators and robotic radiosurgery seems to be possible. H. de las Heras works part‐time as consultant at QUART GmbH, the company that manufacturers the detector Nonius. F. Schoefer is th scientific leader of QUART GmbH. S. Szeglin and D. Coll work for CNMC Co., the company that distributes the detector Nonius in North America. O. Blanck works for German Cyberknife Services. K. Mair has no conflict of interest.

Inhibition of non-target languages in multilingual word production: Evidence from Uighur–Chinese–English trilinguals

The present study examined the hypothesis whether non-target languages are inhibited during multilingual language production by examining the n-2 language repetition cost. In two experiments, Uighur–Chinese–English trilinguals named Arabic digits in one of their three languages according to a visually presented cue. Significant n-2 repetition costs were obtained in both experiments, which indicate that inhibition exists during multilingual word production. In addition, in Experiment 1, it was also found that the n-2 repetition cost was reduced when cues were highly compatible with the task, which means non-target languages are less inhibited. In Experiment 2, the n-2 repetition cost was increased at a shorter CSI. Taken together, these results indicate that inhibition of non-target languages occurs during multilingual language production, and that efficiency of establishing the target language task schema has an effect on the inhibitory control process.

On the Role of Dissipating Inhibition in Task Switching

The n-2 repetition cost has been explained by persisting inhibition of a previously valid task set which dissipates over time. This account has two implications, namely that the switch cost decreases with the number of tasks involved in switching and that the cost should also be observed in switching between two tasks. Neither of these implications is supported by empirical evidence. An alternative view is briefly discussed.

Too much of a good thing: Stronger bilingual inhibition leads to larger lag-2 task repetition costs

Inhibitory control and monitoring abilities of Hebrew–English bilingual and English monolingual university students were compared, in a paradigm requiring participants to switch between performing three distinct tasks. Inhibitory control was gauged by lag-2 task repetition costs, namely decreased performance on the final trial of sequences of type ABA relative to CBA, due to persisting inhibition of the recently abandoned task. Bilinguals had larger lag-2 repetition costs, which reflect stronger inhibition of a no-longer relevant task to facilitate a switch into a new task. Monitoring ability was measured by the fadeout effect, which reflects adaptation to simpler task demands when a single task block immediately and unexpectedly follows mixed task blocks. Bilinguals did not differ from monolinguals in the magnitude or trajectory of the fade-out effect. Thus, results support the notion of increased bilingual inhibitory control, even when it is detrimental to performance, and do not demonstrate a specific bilingual advantage in monitoring. These findings are discussed in the context of the recent debate concerning the locus of bilingual advantages.

Partial repetition costs persist in nonsearch compound tasks: Evidence for multiple-weighting-systems hypothesis

Search performance is sequence-dependent. A specific finding observed in compound-search tasks consists of an interaction between cross-trial sequences (repetition vs. change) of the target-defining (primary) and response-defining (secondary) features: The effect of a target change is greater when the response stays the same than when the response changes. The present study tested whether this interaction arises from processes involved in target search or from later processes in compound tasks. Uncertainty about the upcoming target location-that is, the search component of compound tasks-was removed in different experiments, either by the use of exogenous spatial precues or by presenting only one, central item. Despite having removed the search component, we observed a robust interaction between target (primary) and response (secondary) feature sequences. These results suggest that this interaction originates from a processing stage concerned with discriminating the response feature of a single (selected) item, rather than from a search-related stage. Furthermore, the results support our multiple-weighting-systems hypothesis, according to which sequence effects in visual search tasks do not stem from a single, unitary mechanism; rather, multiple stages of processing on any given trial can lead to separate memory traces, which in turn have effects on different stages of processing on the subsequent trial.

On costs and benefits of n−2 repetitions in task switching: towards a behavioural marker of cognitive inhibition

Inhibition in task switching is inferred from slower reaction times returning to a recently performed task after one intervening trial (i.e. an ABA sequence) compared to returning to a task not recently performed (CBA sequence). These n-2 repetition costs are thought to reflect the persisting inhibition of a task after its disengagement. As such, the n-2 repetition cost is an attractive tool for the researcher interested in inhibitory functioning in clinical/neurological/neuroscience disciplines. In the literature, an absence of this cost is often interpreted as an absence of inhibition, an assumption with strong implications for researchers. The current paper argues that this is not necessarily an accurate interpretation, as an absence of inhibition should lead to an n-2 repetition benefit as a task's activation level will prime performance. This argument is supported by three instances of a computational cognitive model varying the degree of inhibition present. An inhibition model fits human n-2 repetition costs well. Removal of the inhibition-the activation-only model-predicts an n-2 repetition benefit. For the model to produce a null n-2 repetition cost, small amounts of inhibition were required-the reduced-inhibition model. The authors also demonstrate that a lateral-inhibition locus of the n-2 repetition cost cannot account for observed human data. The authors conclude that a null n-2 repetition cost provides no evidence on its own for an absence of inhibition, and propose reporting of a significant n-2 repetition benefit to be the best evidence for a lack of inhibition. Implications for theories on task switching are discussed.

Inhibitory Processes for Critical Situations – The Role of n−2 Task Repetition Costs in Human Multitasking Situations

The human cognitive system is equipped with various processes for dealing with everyday challenges. One of such processes is the inhibition of currently irrelevant goals or mental task-sets, which can be seen as a response to the critical event of information overflow in the cognitive system and challenging the cognitive system’s ability to keep track of ongoing demands. In two experiments, we investigate the flexibility of the inhibitory process by inserting rare non-critical events (25% of all trials), operationalized as univalent stimuli (i.e., unambiguous stimuli that call for only one specific task in a multitasking context), and by introducing the possibility to prepare for an upcoming task (Experiment 2). We found that the inhibitory process is not influenced by a cue informing subjects about the upcoming occurrence of a univalent stimulus. However, the introduction of univalent stimuli allowed preparatory processes to modify the impact of the inhibitory process. Therefore, our results suggest that inhibitory processes are engaged in a rather global manner, not taking into account variations in stimulus valence, which we took as operationalization of critical, conflict-inducing events in the ongoing stream of information processing. However, rare uncritical events, such as univalent stimuli that do not cause conflict and interference in the processing stream, appear to alter the way the cognitive system can take advantage of preparatory processes.

Fast Algorithms of the Simulation Analysis of the Thermal Stresses on Concrete Dams during Construction Periods

During the simulation analysis solution on temperature control and thermal stresses fields of concrete dams’ construction, it is so huge finite element meshes, complex environmental conditions of construction, difficulties in boundary features description that its computational process is time-consuming and consumes far too much storage space. To solve the problem above and reduce calculations, two fast algorithms are introduced. One is the Overall Planning algorithm which makes the simulation process eliminate repetitive costs; the other is the Incomplete Cholesky Conjugate Gradient algorithm including element by element which accelerates the solution of systems of linear equations of the finite element method and requires less storage space. Based on two algorithms above, the calculation program is developed to process the simulation analysis of the finite element model of a million DOF on personal computers and applied to the temperature forecasts and optimized design of temperature control measures in several high concrete dams. It is shown that the calculation results are reliable and accurate, the acceleration is very efficient.

The role of task preparation and task inhibition in age-related task-switching deficits.

The aim of our study was to examine the role of task preparation and task inhibition in age-related task-switching deficits. In 2 experiments, we used a cuing paradigm with 3 tasks and manipulated the cue-stimulus interval (CSI). Additionally, switching among 3 tasks enabled us to examine n-2 task repetition costs, which reflect persisting inhibition of abandoned tasks. In Experiment 1, we found larger mixing costs (i.e., performance in mixed-task blocks vs. single-task blocks) in older adults than in young adults, and preparation effects were smaller in older adults than in young adults. In Experiment 2, where CSIs were blocked instead of randomly varied, we replicated reduced effects of task preparation in older adults. N-2 task repetition costs were not significant in Experiment 1 but significant in Experiment 2, and these costs did not differ across age groups in both experiments. The data suggest a task-preparation deficit in older adults that contributes to increased mixing costs in older adults.

Response to an intervening event reverses nonspatial repetition effects in 2AFC tasks: Nonspatial IOR?

The repetition effect in two-alternatiave forced choice (2AFC) tasks is a cornerstone effect in human cognition. Yet the experiments described here show that the customary benefit of repetition reverses to a cost of repetition when participants respond to an irrelevant event between targets. In Experiments 1A-1C, participants made manual 2AFC decisions to both of two consecutive targets on a trial and, on some trials, also made a manual response to an intervening event that appeared between the two targets. A repetition benefit was observed when no intervening event appeared, whereas a repetition cost was observed when a response was required to an intervening event. Experiment 2 ruled out a solely strategic interpretation of the repetition cost effect observed on intervening event trials. In Experiments 3A and 3B, an intervening event that required a simple vocal "go" response also produced a repetition cost. In Experiment 4, a repetition cost was observed when the intervening event was changed to a tone presented aurally. In Experiment 5, the repetition benefit was observed when a response was withheld to an intervening event. A dual-process interpretation of these results is discussed, with one process related to episodic integration, and the other related to processes that produce inhibition of return.

Spatial and identity negative priming in audition: Evidence of feature binding in auditory spatial memory

Two experiments are reported with identical auditory stimulation in three-dimensional space but with different instructions. Participants localized a cued sound (Experiment 1) or identified a sound at a cued location (Experiment 2). A distractor sound at another location had to be ignored. The prime distractor and the probe target sound were manipulated with respect to sound identity (repeated vs. changed) and location (repeated vs. changed). The localization task revealed a symmetric pattern of partial repetition costs: Participants were impaired on trials with identity-location mismatches between the prime distractor and probe target-that is, when either the sound was repeated but not the location or vice versa. The identification task revealed an asymmetric pattern of partial repetition costs: Responding was slowed down when the prime distractor sound was repeated as the probe target, but at another location; identity changes at the same location were not impaired. Additionally, there was evidence of retrieval of incompatible prime responses in the identification task. It is concluded that feature binding of auditory prime distractor information takes place regardless of whether the task is to identify or locate a sound. Instructions determine the kind of identity-location mismatch that is detected. Identity information predominates over location information in auditory memory.

Target-to-target repetition cost and location negative priming are dissociable: Evidence for different mechanisms.

In a location-selection task, the repetition of a prior distractor location as the target location would slow down the response. This effect is termed the location negative priming (NP) effect. Recently, it has been demonstrated that repetition of a prior target location as the current target location would also slow down response. Because such target-to-target repetition cost is similar to the phenomenon of inhibition of return (IOR), the possibility of a common mechanism underlying target-to-target repetition cost, location NP, and IOR has been proposed. The current study evaluated this hypothesis by combining a spatial-cuing task with a location NP task. The results of three experiments demonstrated that although IOR interacted with target-to-target repetition cost, there was no interaction between IOR and location NP. These findings suggest that target-to-target repetition cost is more likely to share a common mechanism with IOR, and target-to-target repetition cost and location NP should be attributed to different processes.

Task preparation and task inhibition: a comment on Koch, Gade, Schuch, & Philipp (2010)

In their recent review article, Koch, Gade, Schuch, & Philipp, (Psychonomic Bulletin & Review, 17, 1-14, 2010) present compelling evidence for the role of inhibition in task switching, as measured by n-2 repetition costs. They promote the view that inhibition targets response-related processes of task performance rather than cue-based preparatory stages. In support of this distinction, they cite the finding in the literature that n-2 repetition costs are not reduced given longer preparation intervals. In this article, we advocate the analysis of whole reaction time distributions for investigating the influence of task preparation on task inhibition. We present such analyses from two of our published experiments that support the view that n-2 repetition costs can be reduced given sufficient preparation. The results suggest that cue-based processes do contribute to inhibition in task switching.

The role of inhibition in task switching: A review

The concept of inhibition plays a major role in cognitive psychology. In the present article, we review the evidence for the inhibition of task sets. In the first part, we critically discuss empirical findings of task inhibition from studies that applied variants of the task-switching methodology and argue that most of these findings-such as switch cost asymmetries-are ambiguous. In the second part, we focus on n-2 task-repetition costs, which currently constitute the most convincing evidence for inhibition of task sets. n-2 repetition costs refer to the performance impairment in sequences of the ABA type relative to CBA, which can be interpreted in terms of persisting inhibition of previously abandoned tasks. The available evidence suggests that inhibition is primarily triggered by conflict at selection of stimulus attributes and at the response level.

Attention, awareness of contingencies, and control in spatial localization: A qualitative difference approach.

The qualitative difference method for distinguishing between aware and unaware processes was applied here to a spatial priming task. Participants were asked simply to locate a target stimulus that appeared in one of four locations, and this target stimulus was preceded by a prime in one of the same four locations. The prime location predicted the location of the target with high probability (p = .75), but prime and target mismatched on a task-relevant feature (identity, color). Across 5 experiments, we observed repetition costs in the absence of awareness of the contingency, and repetition benefits in the presence of awareness of the contingency. These results were particularly clear-cut in Experiment 4, in which awareness was defined by reference to self-reported strategy use. Finally, Experiment 5 showed that frequency-based implicit learning effects were present in our experiments but that these implicit learning effects were not strong enough to override repetition costs that pushed performance in the opposite direction. The results of these experiments constitute a novel application of the qualitative difference method to the study of awareness, learning of contingencies, and strategic control.

Temporal cue–target overlap is not essential for backward inhibition in task switching

Lag 2 repetition costs are a performance cost observed when participants return to a task after just one intervening trial of a different task, compared to returning after a longer interval (ABA vs. CBA sequences, where A, B, C are tasks). This effect is known as backward inhibition (BI) and is thought to reflect the need to overcome inhibition applied specifically to Task "A" during disengagement at trial n - 1. Druey and Hubner (2007) have suggested that employment of such a specific inhibitory mechanism relies upon the cue and the target of the task overlapping temporally. We provide evidence across three experiments (including a direct replication attempt) that this is not the case, and that the presence of task-specific BI relies to some extent on the need to translate the cue-target relationship into working memory. Additionally, we provide evidence that faster responses in no overlap conditions are driven by low-level perceptual differences between target displays across overlap conditions. We conclude that BI is an effective sequential control mechanism, employed equally in cases of temporally overlapping and temporally separated cues and targets.

Inhibition in language switching: What is inhibited when switching between languages in naming tasks?

When people switch between languages, inhibition of currently irrelevant languages is assumed to occur. The authors examined inhibition of irrelevant languages with a cued language-switching paradigm. A cue indicated in which of 3 languages (German, English, or French) a visual stimulus was to be named. In 2 experiments, the authors found that naming latencies were increased in n-2 language repetitions (e.g., German/English/German) compared with in n-2 language nonrepetitions (e.g., French/English/German). This difference (n-2 repetition costs) indicates persisting inhibition of abandoned languages. It is important to note that n-2 language-repetition costs also occurred in conditions in which the language but not the cue (Experiment 1) or the stimulus/response set (Experiment 2) repeated from trial n-2 to trial n. These data demonstrate that inhibition is not restricted to a specific cue or stimulus/response set. Rather, the data suggest more global inhibitory processes that affect the mental representation of competing languages.