Accuracy Instructions Research Articles

Conflict Monitoring Across the Life Span

Errors can play a major role for optimizing subsequent performance: Response conflict associated with (near) errors signals the need to recruit additional control resources to minimize future conflict. However, so far it remains open whether children and older adults also adjust their performance as a function of preceding response conflict. To examine the life span development of conflict detection and resolution, response conflict was elicited during a task-switching paradigm. Electrophysiological correlates of conflict detection for correct and incorrect responses and behavioral indices of post-error adjustments were assessed while participants in four age groups were asked to focus on either speed or accuracy. Despite difficulties in resolving response conflict, the ability to detect response conflict as indexed by the Ne/ERN component was expected to mature early and be preserved in older adults. As predicted, reliable Ne/ERN peaks were detected across age groups. However, only for adults Ne/ERN amplitudes associated with errors were larger compared to Nc/CRN amplitudes for correct trials under accuracy instructions, suggesting an ongoing maturation in the ability to differentiate levels of response conflict. Behavioral interference costs were considerable in both children and older adults. Performance for children and older adults deteriorated rather than improved following errors, in line with intact conflict detection, but impaired conflict resolution. Thus, participants in all age groups were able to detect response conflict, but only young adults successfully avoided subsequent conflict by up-regulating control.

Individual differences in response speed and accuracy are associated to specific brain activities of two interacting systems.

The study investigates the neurocognitive stages involved in the speed-accuracy trade-off (SAT). Contrary to previous approach, we did not manipulate speed and accuracy instructions: participants were required to be fast and accurate in a go/no-go task, and we selected post-hoc the groups based on the subjects’ spontaneous behavioral tendency. Based on the reaction times, we selected the fast and slow groups (Speed-groups), and based on the percentage of false alarms, we selected the accurate and inaccurate groups (Accuracy-groups). The two Speed-groups were accuracy-matched, and the two Accuracy-groups were speed-matched. High density electroencephalographic (EEG) and stimulus-locked analyses allowed us to observe group differences both before and after the stimulus onset. Long before the stimulus appearance, the two Speed-groups showed different amplitude of the Bereitschaftspotential (BP), reflecting the activity of the supplementary motor area (SMA); by contrast, the two Accuracy-groups showed different amplitude of the prefrontal negativity (pN), reflecting the activity of the right prefrontal cortex (rPFC). In addition, the post-stimulus event-related potential (ERP) components showed differences between groups: the P1 component was larger in accurate than inaccurate group; the N1 and N2 components were larger in the fast than slow group; the P3 component started earlier and was larger in the fast than slow group. The go minus no-go subtractive wave enhancing go-related processing revealed a differential prefrontal positivity (dpP) that peaked at about 330 ms; the latency and the amplitude of this peak were associated with the speed of the decision process and the efficiency of the stimulus-response mapping, respectively. Overall, data are consistent with the view that speed and accuracy are processed by two interacting but separate neurocognitive systems, with different features in both the anticipation and the response execution phases.

Speed pressure in conflict situations impedes inhibitory action control in Parkinson's disease

The current study investigated the effects of Parkinson's disease (PD) on the ability to resolve conflicts when performance emphasized speed vs. response accuracy. PD patients and healthy controls (HC) completed a Simon task, and a subset of participants provided movement-related potential (MRP) data to investigate motor cortex activation and inhibition associated with conflict resolution. Both groups adjusted performance strategically with speed or accuracy instructions. The groups experienced similar susceptibility to making fast errors in conflict trials, but PD patients were less proficient compared to HC at suppressing incorrect responses, especially under speed pressure. Analysis of MRPs showed attenuated inhibition of the motor cortex controlling the conflicting response in PD patients compared to HC. These results confirm the detrimental effects of PD on inhibitory control mechanisms with speed pressure and also suggest that a downstream effect of inhibitory dysfunction in PD might be due to diminished inhibition of the motor cortex.

Reactive and Proactive Control Adjustments under Increased Depressive Symptoms: Insights from the Classic and Emotional-Face Stroop Task

The current research investigated differences in reactive and proactive cognitive control as a function of depressive symptomatology. Three participant groups with varying symptom levels (Beck Depression Inventory-II, BDI-II score) completed both the classic and an emotional-face Stroop task separately under speed and accuracy instructions. All groups made equivalent speed-accuracy trade-offs independent of task, suggesting that proactive adjustments are unaffected by depressive symptoms. Additionally, groups made equivalent reactive control adjustments (Stroop effects, congruency sequence effects) in the classic Stroop task, suggesting that these reactive control adjustments are spared across a wide range of BDI-II scorers. In contrast, the high BDI-II group displayed a selective impairment in the resolution of conflict in the emotional-face Stroop task. Thus, while proactive control and many aspects of reactive control were unaffected by the level of depressive symptoms, specific impairments occurred when current task demands required the trial-to-trial regulation of emotional processing.

Impairment in Flexible Regulation of Speed and Accuracy in Children with ADHD

Attention deficit hyperactivity disorder (ADHD) is characterized by poor adaptation of behavior to environmental demands, including difficulties in flexibly regulating behavior. To understand whether ADHD is associated with a reduction of strategic flexibility in modulating speed and accuracy, we used a perceptual decision-making task that required participants to randomly stress either fast or accurate responding. Thirty-one drug-free boys with ADHD combined-type (mean age: 10.2 years) and 33 healthy control boys (mean age: 10.7 years), matched for age and IQ, participated. Both reaction time and accuracy data were analyzed. Our findings demonstrated significantly lower accuracy in ADHD children than in controls when switching from speed to accuracy instructions. This deficit was directly associated with hyperactivity symptoms but not with inattention. Our results showed that ADHD is associated with a deficit in dynamically switching response strategy according to task demands on a trial-to-trial basis.

Adjustments of Response Threshold during Task Switching: A Model-Based Functional Magnetic Resonance Imaging Study

Adjustment of response threshold for speed compared with accuracy instructions in two-choice decision-making tasks is associated with activation in the fronto-striatal network, including the pre-supplementary motor area (pre-SMA) and striatum (Forstmann et al., 2008). In contrast, increased response conservativeness is associated with activation of the subthalamic nucleus (STN) (Frank et al., 2007). We investigated the involvement of these regions in trial-by-trial adjustments of response threshold in humans, using a cued-trials task-switching paradigm. Fully and partially informative switch cues produced more conservative thresholds than repeat cues. Repeat cues were associated with higher activation in pre-SMA and striatum than switch cues. For all cue types, individual variability in response threshold was associated with activation level in pre-SMA, with higher activation linked to lower threshold setting. In the striatum, this relationship was found for repeat cues only. These findings support the notion that pre-SMA biases the striatum to lower response threshold under more liberal response regimens. In contrast, a high threshold for switch cues was associated with greater activation in right STN, consistent with increasing response caution under conservative response regimens. We conclude that neural models of response threshold adjustment can help explain executive control processes in task switching.

Aging and Error Processing: Age Related Increase in the Variability of the Error-Negativity Is Not Accompanied by Increase in Response Variability

BackgroundSeveral studies report an amplitude reduction of the error negativity (Ne or ERN), an event-related potential occurring after erroneous responses, in older participants. In earlier studies it was shown that the Ne can be explained by a single independent component. In the present study we aimed to investigate whether the Ne reduction usually found in older subjects is due to an altered component structure, i.e., a true alteration in response monitoring in older subjects.Methodology/Principal FindingsTwo age groups conducted two tasks with different stimulus response mappings and task difficulty. Both groups received fully balanced speed or accuracy instructions and an individually adapted deadline in both tasks. Event-related potentials, Independent Component analysis of EEG-data and between trial variability of the Ne were combined with analysis of error rates, coefficients of variation of RT-data and ex-Gaussian fittings to reaction times. The Ne was examined by means of ICA and PCA, yielding a prominent independent component on error trials, the Ne-IC. The Ne-IC was smaller in the older than the younger subjects for both speed and accuracy instructions. Also, the Ne-IC contributed to a much lesser extent to the Ne in older than in younger subjects. RT distribution parameters were not related to Ne/ERP-variability.Conclusions/SignificanceThe results show a genuine reduction as well as a different component structure of the Ne in older compared to young subjects. This reduction is not reflected in behaviour, apart from a general slowing of older participants. Also, the Ne decline in the elderly is not due to speed accuracy trade-off. Hence, the results indicate that older subjects can compensate the reduction in control reflected in the reduced Ne, at least in simple tasks that induce reaction slips.

Neural Characterization of the Speed–Accuracy Tradeoff in a Perceptual Decision-Making Task

Decisions often necessitate a tradeoff between speed and accuracy (SAT), that is, fast decisions are more error prone while careful decisions take longer. Sequential sampling models assume that evidence for different response alternatives is accumulated over time and suggest that SAT modulates the decision system by setting a lower threshold (boundary) on required accumulated evidence to commit a response under time pressure. We investigated how such a speed accuracy tradeoff is implemented neurally under different levels of sensory evidence. Using magnetoencephalography (MEG) and a face-house categorization task, we show that the later decision- and motor-related systems rather than the early sensory system are modulated by SAT. Source analysis revealed that the bilateral supplementary motor areas (SMAs) and the medial precuneus were more activated under the speed instruction and correlated negatively (right SMA) with the boundary parameter, whereas the left dorsolateral prefrontal cortex (DLPFC) was more activated under the accuracy instruction and showed a positive correlation with the boundary. The findings are interpreted in the sense that SMA activity dynamically facilitates fast responses during stimulus processing, potentially by disinhibiting thalamo-striatal loops, whereas DLPFC reflects accumulated evidence before response execution.

Independent component analysis of erroneous and correct responses suggests online response control

After errors in reaction tasks, a sharp negative wave emerges in the event-related potential (ERP), the error (related) negativity (Ne or ERN). However, also after correct trials, an Ne-like wave is seen, called CRN or Nc, which is much smaller than the Ne. This study tested the hypothesis whether Ne and Nc reflect the same functional process, and whether this process is linked to online response control. For this purpose, independent component analysis (ICA) was utilized with the EEG data of two types of reaction tasks: a flanker task and a mental rotation task. To control for speed-accuracy effects, speed and accuracy instructions were balanced in a between subjects design. For both tasks ICA and dipole analysis revealed one component (Ne-IC) explaining most of the variance for the difference between correct and erroneous trials. The Ne-IC showed virtually the same features as the raw postresponse ERP, being larger for erroneous compared to correct trials and for the flanker than for the rotation task. In addition, it peaked earlier for corrected than for uncorrected errors. The results favor the hypothesis that Ne and Nc reflect the same process, which is modulated by response correctness and type of task. On the basis of the literature and the present results, we assume that this process induces online response control, which is much stronger in error than correct trials and with direct rather than indirect stimulus response mapping.

The relation of aerobic fitness to neuroelectric indices of cognitive and motor task preparation

The relation of aerobic fitness to task preparation was examined in a sample of young adults separated into higher- and lower-fit groups according to their maximal oxygen consumption. Participants performed a modified Sternberg working memory task under speed and accuracy instructions while measures of task performance and contingent negative variation (CNV) were collected. Analyses revealed no significant fitness differences between groups on task performance measures. However, frontal CNV amplitude was significantly larger for lower-fit participants compared to higher-fit participants during the speed instructions, an effect not found for the accuracy instructions. These results suggest that lower-fit individuals may rely to a greater extent on cognitive control processes to respond under speeded conditions, whereas higher-fit individuals may maintain a more constant level of control irrespective of the task instructions.

Reading Interventions for Students with Challenging Behavior: A Focus on Fluency

Students with and at risk for emotional and behavioral disorders typically demonstrate low rates of responsiveness to reading interventions. This study examined the effect of implementing a multi-dimensional secondary intervention package on students’ oral reading fluency (ORF). Fluency building was added to accuracy instruction and behavioral support for 4 second-grade students with reading difficulties and behavioral challenges, and 5 students with reading difficulties only. Results indicated that all students benefited; however, 2 students with behavioral challenges responded at greater rates and 2 responded with similar rates of growth compared to students with reading risk alone. Students’ level of attention may have contributed to student responsiveness as students with higher levels of inattention were less responsive to the intervention. Limitations, direction for future research, and educational implementation are discussed.

The impact of instruction and response cost on the modulation of response-style in children with ADHD

BackgroundThe present study investigated the impact of divergent instructions and response cost on strategic cognitive control in children with ADHD.MethodsChildren with ADHD (N = 34), combined subtype, and control children (N = 34) performed a series of self-paced computerized visual search tasks. The tasks varied by verbal instructions: after a baseline task, children were either instructed to work as fast as possible (speed instruction) or as accurately as possible (accuracy instruction). In addition, tasks were performed with and without response cost.ResultsBoth groups modulated latencies and errors according to instructions in a comparable way, except for latency in the accuracy - instruction without response cost, where control children showed a larger increase of response time. Response cost did not affect the modulation of response style in children with ADHD to a larger extent than in controls. However, with instructions group differences related to target criteria became clearly more accentuated compared to baseline but disappeared when response cost was added.ConclusionsDelay aversion theory and motivational or state regulation models may account for different aspects of the results. Modifications related to task presentation, such as the emphasis put on different details in the verbal instruction, may lead to divergent results when comparing performances of children with ADHD and control children on a self-paced task.

Goal Priming and Self-Efficacy: Independent Contributions to Motor Performance

It is well-established that goal pursuit and performance are responsive to the goal characteristics (e.g., difficulty, specificity) and beliefs about self and the task (e.g., self-efficacy). Also, contextual factors may lead to nonconscious goal activation and pursuit. Nevertheless, much remains to be discoverd concerning the way conscious and nonconscious goals are related. In this study, the way in which self-efficacy and nonconscious goal priming may affect a goal-directed activity was explored. 67 right-handed participants with high or low self-efficacy on their motor skills performed a drawing task associated with an accuracy instruction. Before task performance, they were primed with accuracy-related words (goal-compatible condition), inaccuracy-related words (goal-incompatible condition), or received no priming manipulation (control condition). Analysis indicated that performance of the motor task was independently influenced by self-efficacy and goal priming.

Effects of speed–accuracy instructions on oculomotor scanning and target recognition in a simulated baggage X-ray screening task

Visual search tasks are often carried out under high levels of time stress. Transportation security screeners, for example, face demands to achieve high levels of accuracy while maintaining rapid passenger throughput. An experiment examined the strategies by which operators regulate visual search performance under such conditions. Observers performed a simulated baggage-screening task under instructions to emphasise either response speed or accuracy. Behavioural measures and eye movements were recorded. Observers made fewer and briefer fixations under emphasise-speed than under emphasise-accuracy instructions. Losses in accuracy were produced by more frequent failures to fixate on targets and a decrease in the detection rate of non-fixated targets. The likelihood with which observers detected a fixated target was similar across speed–accuracy instructions. Results will inform efforts to model visual search in naturalistic tasks, allowing more accurate prediction of response times and error rate and may aid the design of training programmes and other interventions to improve search performance under stress.

The effect of speed-accuracy strategy on response interference control in Parkinson's disease

Studies that used conflict paradigms such as the Eriksen Flanker task show that many individuals with Parkinson's disease (PD) have pronounced difficulty resolving the conflict that arises from the simultaneous activation of mutually exclusive responses. This finding fits well with contemporary views that postulate a key role for the basal ganglia in action selection. The present experiment aims to specify the cognitive processes that underlie action selection deficits among PD patients in the context of variations in speed-accuracy strategy. PD patients (n=28) and healthy controls (n=17) performed an arrow version of the flanker task under task instructions that either emphasized speed or accuracy of responses. Reaction time (RT) and accuracy rates decreased with speed compared to accuracy instructions, although to a lesser extent for the PD group. Differences in flanker interference effects among PD and healthy controls depended on speed-accuracy strategy. Compared to the healthy controls, PD patients showed larger flanker interference effects under speed stress. RT distribution analyses suggested that PD patients have greater difficulty suppressing incorrect response activation when pressing for speed. These initial findings point to an important interaction between strategic and computational aspects of interference control in accounting for cognitive impairments of PD. The results are also compatible with recent brain imaging studies that demonstrate basal ganglia activity to co-vary with speed-accuracy adjustments.

The “Not Letting Go” phenomenon: accuracy instructions can impair behavioral and metacognitive effects of implicit learning processes

One major assumption in the field of implicit learning is that implicit learning processes directly affect performance without further top-down control (e.g., Destrebecqz and Cleeremans 2003). In three related experiments, the authors tested the so-called "Not Letting Go Phenomenon" (Schneider and Fisk in J Exp Psychol Learn Mem Cogn 8:261-278, 1982); that is, the assumption that accuracy instructions might impair the effect of implicit learning processes during skill acquisition. Results of Experiment 1 show that accuracy instructions can impair both, the behavioral and metacognitive effects of implicit learning. Experiments 2 and 3 indicate that this impairment is due more to an impairment of the performance effects of implicit learning processes than to a direct impairment of the learning processes, per se. While these results are in accordance with recent findings in skill acquisition showing that monitoring processes impede experts' performance, they seem to contradict the above mentioned assumption that implicit learning processes directly affect performance.

Effects of Task Instructions and Target Location on Reaching Kinematics in People With and Without Cerebrovascular Accident: A Study of the Less-Affected Limb

We investigated how verbal instructions and target location interacted to influence reaching movement of the less-affected limb in participants with and without unilateral cerebrovascular accidents (CVAs). Using a counterbalanced repeated-measures design, 26 people with CVA and 24 age-matched healthy people performed the reaching tasks under 4 conditions formed by the crossing of verbal instructions (speed and accuracy emphasis) and target locations (ipsilateral and contralateral to the performing hand). In the control groups, speeded instructions and ipsilateral reaches elicited significantly more preprogrammed movements than did accuracy instruction and contralateral reaches, respectively. Similar patterns of performance in response to task constraints were found in the CVA groups except for movement initiation in the right CVA group. Instruction and locations interacted to constrain reaching movements in both control and CVA groups. The combination of speeded instruction and ipsilateral reach may optimize movement performance of the less-affected limb in stroke patients.

On the automatic nature of the task-appropriate processing effect in event-based prospective memory

This research tested competing predictions about the cognitive processes underlying the task-appropriate processing effect in prospective memory. Participants had to press a designated key whenever a word from the semantic category of animals or from the structural category of palindromes occurred in an ongoing lexical decision task. The availability of attentional resources was manipulated by varying the effort to the ongoing task in terms of speed or accuracy. In the task-appropriate semantic prospective memory task, performance was robust against the speed versus accuracy instructions. In the task-inappropriate structural prospective memory task, performance declined under speed instructions that detracted attentional resources. Accordingly, a facilitating effect of task-appropriate processing was observed under speed instructions but not accuracy instructions. The results support the notion that the task-appropriate processing effect is due to a larger contribution of automatic cue detection to prospective memory performance under task-appropriate than task-inappropriate conditions.

Age-dependent changes of auditory evoked potentials—Effect of task difficulty

The goal of this study was to evaluate the patterns of age-dependent changes of P3 components of auditory event-related potentials exploring the effects of task difficulty. The participants (age span: 19–68 years, n=55, divided into five age groups) took part in an easy and in a difficult two-tone oddball frequency discrimination task with speed or accuracy instructions, and in a novelty oddball task. The latency of the P3 components increased with aging. While in the easy task a linear P3b latency increase could be seen, in the difficult tasks (difficult frequency discrimination or distracting novel stimuli) an accelerated latency increase was observed for the P3b and P3a. In the two-tone oddball paradigm age had no effect on P3b amplitude, but in the novelty oddball task the amplitude of P3 potentials decreased with age. These results indicate that distracting stimuli increase task demands, and in difficult tasks decay can be observed more easily due to the accumulation of various processing mechanisms characterizing aging.

A diffusion model account of criterion shifts in the lexical decision task

Performance in the lexical decision task is highly dependent on decision criteria. These criteria can be influenced by speed versus accuracy instructions and word/nonword proportions. Experiment 1 showed that error responses speed up relative to correct responses under instructions to respond quickly. Experiment 2 showed that responses to less probable stimuli are slower and less accurate than responses to more probable stimuli. The data from both experiments support the diffusion model for lexical decision [Ratcliff, R., Gomez, P., & McKoon, G. (2004a). A diffusion model account of the lexical decision task. Psychological Review, 111, 159–182]. At the same time, the data provide evidence against the popular deadline model for lexical decision. The deadline model assumes that “nonword” responses are given only after the “word” response has timed out—consequently, the deadline model cannot account for the data from experimental conditions in which “nonword” responses are systematically faster than “word” responses.