Reduction Of Switch Costs Research Articles

Does preparation help to switch auditory attention between simultaneous voices: Effects of switch probability and prevalence of conflict.

Switching auditory attention to one of two (or more) simultaneous voices incurs a substantial performance overhead. Whether/when this voice 'switch cost' reduces when the listener has opportunity to prepare in silence is not clear-the findings on the effect of preparation on the switch cost range from (near) null to substantial. We sought to determine which factors are crucial for encouraging preparation and detecting its effect on the switch cost in a paradigm where participants categorized the number spoken by one of two simultaneous voices; the target voice, which changed unpredictably, was specified by a visual cue depicting the target's gender. First, we manipulated the probability of a voice switch. When 25% of trials were switches, increasing the preparation interval (50/800/1,400 ms) resulted in substantial (~50%) reduction in switch cost. No reduction was observed when 75% of trials were switches. Second, we examined the relative prevalence of low-conflict, 'congruent' trials (where the numbers spoken by the two voices were mapped onto the same response) and high-conflict, 'incongruent' trials (where the voices afforded different responses). 'Conflict prevalence' had a strong effect on selectivity-the incongruent-congruent difference ('congruence effect') was reduced in the 66%-incongruent condition relative to the 66%-congruent condition-but conflict prevalence did not discernibly interact with preparation and its effect on the switch cost. Thus, conditions where switches of target voice are relatively rare are especially conducive to preparation, possibly because attention is committed more strongly to (and/or disengaged less rapidly from) the perceptual features of target voice.

Is the juice worth the squeeze? Learning the marginal value of mental effort over time.

In keeping with the view that individuals invest cognitive effort in accordance with its relative costs and benefits, reward incentives typically improve performance in tasks that require cognitive effort. At the same time, increasing effort investment may confer larger or smaller performance benefits-that is, the marginal value of effort-depending on the situation or context. On this view, we hypothesized that the magnitude of reward-induced effort modulations should depend critically on the marginal value of effort for the given context, and furthermore, the marginal value of effort of a context should be learned over time as a function of direct experience in the context. Using two well-characterized cognitive control tasks and simple computational models, we demonstrated that individuals appear to learn the marginal value of effort for different contexts. In a task-switching paradigm (Experiment 1), we found that participants initially exhibited reward-induced switch cost reductions across contexts-here, task switch rates-but over time learned to only increase effort in contexts with a comparatively larger marginal utility of effort. Similarly, in a flanker task (Experiment 2), we observed a similar learning effect across contexts defined by the proportion of incongruent trials. Together, these results enrich theories of cost-benefit effort decision-making by highlighting the importance of the (learned) marginal utility of cognitive effort. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Minimal impact of consolidation on learned switch-readiness.

Adaptive behavior is characterized by our ability to create, maintain, and update (or switch) rules by which we categorize and respond to stimuli across changing contexts (cognitive flexibility). Recent research suggests that people can link the control process of task-switching to contextual cues through associative learning, whereby the behavioral cost of switching is reduced for contexts that require frequent switching. One example is the listwide proportion switch (LWPS) effect, denoting smaller switch costs in blocks of trials where switching is more frequent. However, the conditions that govern such learned cognitive flexibility are poorly understood. One major unanswered question is whether this type of learning benefits from memory consolidation effects. To address this question, we manipulated whether task-sets and/or specific task stimuli were more frequently linked with task-switching (vs. repeating), and ran participants over two experimental sessions, separated by a 24-hr delay. We expected that consolidation would facilitate learned cognitive flexibility, resulting in a greater reduction of switch costs with increasing task-switch likelihood on Session 2 compared with Session 1. Across two experiments, we observed robust LWPS effects in both sessions. However, we found little evidence for effects of consolidation on learned cognitive flexibility: The magnitude of the LWPS effect did not change from Session 1 to 2. Altogether our results suggest that people reliably and quickly acquire task-set and stimulus-based switch associations, but this form of control learning-unlike many instances of reward-based learning-does not benefit from long-term memory consolidation. Possible reasons for these findings are discussed. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

It's all relative: Reward-induced cognitive control modulation depends on context.

Although people seek to avoid expenditure of cognitive effort, reward incentives can increase investment of processing resources in challenging situations that require cognitive control, resulting in improved performance. At the same time, subjective value is relative, rather than absolute: The value of a reward is increased if the local context is reward-poor versus reward-rich. Although this notion is supported by work in economics and psychology, we propose that reward relativity should also play a critical role in the cost-benefit computations that inform cognitive effort allocation. Here we demonstrate that reward-induced cognitive effort allocation in a task-switching paradigm is sensitive to reward context, consistent with the notion of relative value. Informed by predictions of a computational model of divisive reward normalization, we demonstrate that reward-induced switch cost reductions depend critically upon reward context, such that the same reward amount engenders greater control allocation in impoverished versus rich reward context. Succinctly, these results confirm that reward relativity factors into the value computation driving effort allocation, revealing that motivated cognitive control, like choice, is all relative. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Task-evoked pupillary responses track effort exertion: Evidence from task-switching.

A spate of research has examined how individuals regulate effortful processing in service of goal-directed behaviors. One key challenge in developing an account of this regulation is quantifying the momentary amount of cognitive effort exerted by an individual in service of their goals. A growing body of literature has suggested using task-evoked pupil dilations as a potential psychophysiological index of cognitive effort; however, it remains unclear whether pupil diameter indexes effort exertion or merely reflects task load, as both are tightly intertwined. Here, we attempt to disentangle these disparate accounts of pupil diameter by leveraging individual differences in executive function (as measured by Stroop interference) and a motivational manipulation (i.e., monetary incentives) while participants complete a task-switching paradigm. In line with both the effort and demand accounts, we observed larger task-evoked pupillary responses (TEPRs) for trials in which there was a task switch versus a task repetition. Additionally, we found that larger phasic pupillary responses at baseline (without reward incentives) predicted smaller switch costs. Mirroring this pattern, individual differences in reward-induced switch cost reductions were predicted by reward-induced increases in phasic pupil diameter. Finally, we observed that the interrelationship between effort and pupil diameter at baseline was modulated by individual differences in Stroop interference costs. Together, these findings provide support for an effort account of TEPRs, and suggest that pupillometry is a viable index of cognitive effort.

Can we prepare to attend to one of two simultaneous voices?

We can selectively attend to one of two simultaneous voices sharing a source location. Can we endogenously select the voice before speech is heard? Participants heard two digit names, spoken simultaneously by a male voice and a female voice, following a visual cue indicating which voice's digit to classify as odd or even. There was a substantial cost in reaction time and errors when the target voice switched from one trial to the next. In Experiment 1, with a highly familiar pair of voices, the switch cost reduced by nearly half as the cue-stimulus interval increased from 50 to 800 ms, indicating (contrary to previous reports) effective endogenous preparation for a change of voice. No further reduction in switch cost occurred with a longer preparation interval-this "residual" switch cost may be attributable to attentional "inertia." In Experiment 2, with previously unfamiliar voices, the pattern of switch costs was very similar, though repeated attention to the same target voice over a run of trials improved performance more. Delaying the onset of one voice by 366 ms improved performance, but the pattern of preparatory tuning effects was similar. Thus, endogenous preparation for a voice is possible, but it is limited in efficacy, as for some other attentional domains. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Optimal fuzzy switch placement to increase automation level of electric distribution network considering asset management principles

Since distribution sector is inherent into high amount of failures, distribution companies (DISCOs) are responsible of attaining an acceptable value for the reliability indices and otherwise they will face up to complaints. So they are usually obligated by regulators to invest on reliability improvement of network. But this investment on reliability is usually from the DISCO’s viewpoint and is also irrespective of customer satisfaction level. In other words, customers are not at the same level of sensitivity to interruptions but DISCO improves the reliability of network without considering the differences in importance degree of loads and their level of reliability requirement. On the other hand DISCOs attempt to reduce their investment costs as much as possible. This paper introduces a novel approach in the field of joint switch placement that can reduce the switch cost from the perspective of asset management policies. To this end, two switch placement plannings in different types of strategies are performed to compare their results. Firstly as witch placement is performed based on reducing the total energy not supplied (ENS) of the system. Then by revising the strategy, a fuzzy switch placement is performed from the DISCO’s point of view which just considers the total ENS of load points most sensitive to interruptions known as important or critical loads. Furthermore, by meeting the related constraints, the reliability of low sensitive customers is disregarded. This is a load importance based planning which can result in switch cost reduction relative to the amount achieved in previous strategy and implies the management of risks associated with reliability and respective constraint. Fuzzy method and new switching mechanism in fuzzy environment of network are implemented to modeling and controlling the risks associated to ENS of critical loads and also the ENS of system.

Investigating the impact of dynamic and static secondary tasks on task-switch cost.

Many researchers have employed secondary tasks, which have to be performed in parallel with a primary task requirement, to examine how successful task selection is accomplished in the context of task switching. The influence of such a secondary task on the observed switch cost (i.e., the cost arising when the currently relevant task differs from the task performed most recently) is seen as indicative that cognitive processes such as self-instruction are involved. Most secondary tasks chosen so far have required the repeated utterance of a word or syllable or a rhythmic movement of the foot. In the present study, we manipulated the dynamics of the to-be-performed secondary task (i.e., a repeated utterance or movement, or a static task that involved similar muscles-holding a spattle in the mouth or pressing keys). Additionally, we tested for modality-specific influences by asking participants to perform a dynamic or nondynamic (i.e., static) secondary task with two effector systems, namely oral and manual. Overall, our secondary tasks led to a reduced (rather than an increased) switch cost, as compared to a control condition without any secondary task. This reduction in switch cost was dependent on the secondary-task dynamics but independent of the effectors involved, showing larger switch-cost reductions for dynamic secondary tasks. To explain this finding, we suggest that performing secondary tasks interferes with the formation of episodic-memory traces that would lead to retrieval benefits in the case of a task repetition, so that our reduced task-switch costs actually represent reduced repetition benefits.

Training and transfer effects of extensive task-switching training in students

The capacity to switch between tasks is a central component of executive functioning. Previous studies assessing effects of task-switch training have revealed mixed results, both in terms of processes that may be improved and the extent of beneficial effects on non-trained tasks. These studies primarily used few training sessions, which may have limited training and transfer effects. Here, 31 students were trained for 21 days on a cued switching task. Both the trained group and an active control group (n = 29) performed a number of cognitive tasks before and after training. Training reduced both switch and mixing costs, which mostly reached an asymptote after approximately four to six training sessions, although there were residual costs at the end of training. The switch cost reduction was restricted to trials with a short cue–stimulus onset interval (CSI). Training benefitted performance on another switching task, reflecting near transfer. However, this benefit was limited to the switch cost and to trials with a short CSI. There were no beneficial effects on far-transfer tasks measuring interference control, response inhibition, working memory, and general IQ. The results suggest that the present extensive training protocol, implicating overtraining, specifically enhanced the efficiency of processes involved in preparing for the relevant upcoming task set and/or inhibition of the previous task set. However, the lack of beneficial far-transfer effects is in line with previous cognitive training studies employing fewer training sessions, suggesting that the extent of training is not critical for (not) finding transfer effects.

Intertrial RT variability affects level of target-related interference in cued task switching.

In cued task switching, performance relies on proactive and reactive control processes. Proactive control is evident in the reduction in switch cost under conditions that promote advance preparation. However, the residual switch cost that remains under conditions of optimal proactive control indicates that, on switch trials, the target continues to elicit interference that is resolved using reactive control. We examined whether posttarget interference varies as a function of trial-by-trial variability in preparation. We investigated target congruence effects on behavior and target-locked ERPs extracted across the response time (RT) distribution, using orthogonal polynomial trend analysis (OPTA). Early N2, late N2, and P3b amplitudes were differentially modulated across the RT distribution. There was a large congruence effect on late N2 and P3b, which increased with RT for P3b amplitude, but did not vary with trial type. This suggests that target properties impact switch and repeat trials equally and do not contribute to residual switch cost. P3b amplitude was larger, and latency later, for switch than repeat trials, and this difference became larger with increasing RT, consistent with sustained carryover effects on highly prepared switch trials. These results suggest that slower, less prepared responses are associated with greater target-related interference during target identification and processing, as well as slower, more difficult decision processes. They also suggest that neither general nor switch-specific preparation can ameliorate the effects of target-driven interference. These findings highlight the theoretical advances achieved by integrating RT distribution analyses with ERP and OPTA to examine trial-by-trial variability in performance and brain function.

Serial or overlapping processing in multitasking as individual preference: Effects of stimulus preview on task switching and concurrent dual-task performance

Understanding the mechanisms and performance consequences of multitasking has long been in focus of scientific interest, but has been investigated by three research lines more or less isolated from each other. Studies in the fields of the psychological refractory period, task switching, and interruptions have scored with a high experimental control, but usually do not give participants many degrees of freedom to self-organize the processing of two concurrent tasks. Individual strategies as well as their impact on efficiency have mainly been neglected. Self-organized multitasking has been investigated in the field of human factors, but primarily with respect to overall performance without detailed investigation of how the tasks are processed. The current work attempts to link aspects of these research lines. All of them, explicitly or implicitly, provide hints about an individually preferred type of task organization, either more cautious trying to work strictly serially on only one task at a time or more daring with a focus on task interleaving and, if possible, also partially overlapping (parallel) processing. In two experiments we investigated different strategies of task organization and their impact on efficiency using a new measure of overall multitasking efficiency. Experiment 1 was based on a classical task switching paradigm with two classification tasks, but provided one group of participants with a stimulus preview of the task to switch to next, enabling at least partial overlapping processing. Indeed, this preview led to a reduction of switch costs and to an increase of dual-task efficiency, but only for a subgroup of participants. They obviously exploited the possibility of overlapping processing, while the others worked mainly serially. While task-sequence was externally guided in the first experiment, Experiment 2 extended the approach by giving the participants full freedom of task organization in concurrent performance of the same tasks. Fine-grained analyses of response scheduling again revealed individual differences regarding the preference for strictly serial processing vs. some sort of task interleaving and overlapping processing. However, neither group showed a striking benefit in dual-task efficiency, although the results show that the costs of multitasking can partly be compensated by overlapping processing.

Guessing versus Choosing an Upcoming Task.

We compared the effects of guessing vs. choosing an upcoming task. In a task-switching paradigm with four tasks, two groups of participants were asked to either guess or choose which task will be presented next under otherwise identical conditions. The upcoming task corresponded to participants’ guesses or choices in 75 % of the trials. However, only participants in the Choosing condition were correctly informed about this, whereas participants in the Guessing condition were told that tasks were determined at random. In the Guessing condition, we replicated previous findings of a pronounced reduction of switch costs in case of incorrect guesses. This switch cost reduction was considerably less pronounced with denied choices in the Choosing condition. We suggest that in the Choosing condition, the signaling of prediction errors associated with denied choices is attenuated because a certain proportion of denied choices is consistent with the overall representation of the situation as conveyed by task instructions. In the Guessing condition, in contrast, the mismatch of guessed and actual task is resolved solely on the level of individual trials by strengthening the representation of the actual task.

An ERP Study of Advantage Effect Differences on Task Switching in Proficient and Non-proficient Bilinguals

Bilinguals have shown an advantage over monolinguals in cognitive functioning. Likely due to their experience of language switching, bilinguals tend to perform better in task switching. Support for such an advantage effect has been obtained by using the task-cueing paradigm. The paradigm, however, may confuse cue-change with task-change. Therefore researchers have developed a modified task-switching paradigm with a 2:1 mapping between cues and tasks. Using this modified paradigm, the present research investigates brain functioning of proficient and non-proficient bilinguals in task switching, and explores whether endogenous preparation accounts for the bilingual advantage in task switching.Two experiments were reported in the current paper. In a behavioral experiment, by using a task-switching paradigm with a 2:1 mapping between cues and tasks, we explored whether proficient bilinguals who constantly switch between two languages in daily life would show advantage over non-proficient bilinguals due to the endogenous preparation of task switching. This experiment, conducted with E-prime, included 30 proficient bilingual and 30 non-proficient bilingual university students. In an ERP experiment involving 11 proficient bilinguals and 11 non-proficient bilinguals, we examined brain activities by observing the wave of D-Pos, as an index of endogenous preparation. The data collection and analyses were conducted with Vision recorder and analyzer Software produced by Brain Products corporation. The experiments found that the reaction time was faster for proficient bilinguals than for non-proficientbilinguals in both task-change and task-repeat sequences, when the cue-stimulus interval was 250 ms, the reaction time and the switching costs were smaller for proficient bilinguals than for non-proficient bilinguals. Most importantly, we observed stronger RISC(Reduction In Switch Cost) effects among proficient bilinguals than among non-proficient bilinguals when the time interval was from 0ms to 250 ms. Used event-related potential, we carried out a further study on time-course features of endogenous preparation with D-Pos as the index. According to the analysis of cue-locked D-Pos component, non-proficient bilinguals presented a more positive component than the proficient bilinguals. We conclude that the experience of using two languages in proficient bilingual improves cognition processing in general, and enhances executive functioning in particular.

The minimum requirements of language control: evidence from sequential predictability effects in language switching.

The current study systematically examined the influence of sequential predictability of languages and concepts on language switching. To this end, 2 language switching paradigms were combined. To measure language switching with a random sequence of languages and/or concepts, we used a language switching paradigm that implements visual cues and stimuli. The other paradigm implements a fixed sequence of languages and/or concepts to measure predictable language switching. Four experiments that used these 2 paradigms showed that switch costs were smaller when both the language and concept were predictably known, whereas no overall switch cost reduction was found when just the language or concept was predictable. These results indicate that knowing both language and concept (i.e., response) can resolve language interference. However, interference resolution does not start solely based on the knowledge of which concept or language one has to produce. We discuss how existent models should be revised to accommodate these results.

What's easier: doing what you want, or being told what to do? Cued versus voluntary language and task switching.

The current study contrasted cued versus voluntary switching to investigate switching efficiency and possible sharing of control mechanisms across linguistic and nonlinguistic domains. Bilinguals switched between naming pictures in Spanish versus English or between reading numbers aloud versus adding their digits, either without or with repetition of stimuli and with fewer requirements as to when and how much they had to switch relative to previous instantiations of voluntary switching. Without repetition (Experiment 1), voluntary responses were faster than cued responses on both stay and switch trials (especially in the nonlinguistic switching task), whereas in previous studies the voluntary advantage was restricted to switch-cost reduction. Similarly, when targets were presented repeatedly (Experiment 2), voluntary responses were faster overall for both linguistic and nonlinguistic switching, although here the advantage tended to be larger on switch trials and cross-domain similarity appeared to reflect nonoverlapping switching strategies. Experiment 3 confirmed the overall voluntary speed advantage for the read-add task in monolinguals and revealed a reduction in switch costs only for a different nonlinguistic task (size-parity judgments). These results reveal greater overall advantages for voluntary over cued switching than previously reported but also that the precise manifestation of the voluntary advantage can vary with different tasks. In the linguistic domain, lexical inaccessibility introduces some unique control mechanisms, and repetition may magnify cross-domain overlap in control mechanisms. Finally, under some limited conditions, cost-free switches were found in both linguistic and nonlinguistic domains; however, suspension of top-down control may be restricted to language or highly automatic tasks.

Component Processes in Voluntary Task Switching

The present study investigated the involvement of bottom-up and top-down control in task-switching situations in which tasks are selected on a voluntary basis. We tested for indices of both types of control in the reduction in switch cost that is observed when more time is available before executing a task. Participants had to indicate their task choice overtly prior to the actual task execution, and two time intervals were manipulated: the interval between the task-execution response of the previous trial and task-indication response of the current trial and the interval between task-indication response and task-execution response of a particular trial. In Experiment 1, the length of these intervals was manipulated orthogonally, and indices for top-down and bottom-up control were observed. Concerned with the validity of these results, Experiments 2-3 additionally discouraged participants from preparing the upcoming task before their task-indication response. Indices for bottom-up control remained, but not for top-down control. The characteristics of top-down and bottom-up control in voluntary task switching and task switching in general are discussed.

Stimulus-level interference disrupts repetition benefit during task switching in middle childhood.

The task-switching paradigm provides a powerful tool to measure the development of core cognitive control processes. In this study, we use the alternating runs task-switching paradigm to assess preparatory control processes involved in flexibly preparing for a predictable change in task and stimulus-driven control processes involved in controlling stimulus-level interference. We present three experiments that examine behavioral and event-related potential (ERP) measures of task-switching performance in middle childhood and young adulthood under low and high stimulus interference conditions. Experiment 1 confirms that our new child-friendly tasks produce similar behavioral and electrophysiological findings in young adults as those previously reported. Experiment 2 examines task switching with univalent stimuli across a range of preparation intervals in middle childhood. Experiment 3 compares task switching with bivalent stimuli across the same preparation intervals in children and young adults. Children produced a larger RT switch cost than adults with univalent stimuli and a short preparation interval. Both children and adults showed significant reduction in switch cost with increasing preparation interval, but in children this was caused by greater increase in RT for repeat than switch trials. Response-locked ERPs showed intact preparation for univalent, but less efficient preparation for bivalent stimulus conditions. Stimulus-locked ERPs confirmed that children showed greater stimulus-level interference for repeat trials, especially with bivalent stimuli. We conclude that children show greater stimulus-level interference especially for repeat trials under high interference conditions, suggesting weaker mental representation of the current task set.

The effect of action video game experience on task-switching

There is now a substantial body of work demonstrating that action video game experience results in enhancements in a wide variety of perceptual skills. More recently, several groups have also demonstrated improvements in abilities that are more cognitive in nature, in particular, the ability to efficiently switch between tasks. We add to this body of work by demonstrating that the action video game player switch cost advantage generalizes to (1) vocal responses in addition to traditional manual responses, (2) tasks that are more cognitive rather than perceptual in nature, and (3) goal switches as well as motor switches. Finally, a training study establishes that the relationship between the reduction in switch cost and action game playing is causal.

Task practice differentially modulates task-switching performance across the adult lifespan

Cued-trials task-switching paradigms have been used extensively to examine ageing-related changes in cognitive control. Many studies report an increase in mixing cost (i.e., cost of repeating the same task in a single-task vs. a mixed-task block) and a less reliable increase in switch cost (i.e., cost of switching vs. repeating tasks in a mixed-task block) in old as compared to young adults. However, there is substantial variability between studies in the emergence and size of age effects on mixing and/or switch cost. In this study, we examined variation in mixing cost and switch cost as a function of task practice and preparation interval across the adult lifespan (18–79 years) using a paradigm that promotes advance preparation and reduces cue encoding differences between switch and repeat trials. Both preparation interval and task practice modulated mixing cost and switch cost—but task practice mediated the effects of preparation interval and age differentially for mixing cost and switch cost. Mixing cost was consistently larger in older participants, reduced with preparation and varied little with task practice. In contrast, the effect of preparation interval on switch cost varied with task practice. Reduction in switch cost with preparation interval emerged in younger participants by the second practice session and even later in older participants. When fully practiced, older participants showed greater mixing cost but less switch cost than younger participants. Age effects on both mixing cost and switch cost were mediated by changes in processing of repeat trials, indicative of reduced differentiation between switch and repeat trials in mixed-task blocks. This is consistent with reduced cognitive flexibility with increasing age.

Diversity of the P3 in the task-switching paradigm

Electrophysiological studies investigating task switching usually reveal results of the parietal P3. In this study we investigated the frontal and parietal P3 after cues, targets and responses in a combined go/no-go task switch paradigm. We confirm behavioral findings showing reduction of switch costs after no-go trials. This was accompanied by a number of P3 findings: first, the cue-locked parietal P3 was increased after a switch relative to a repetition, regardless whether a go or no-go was previously required but the frontal counterpart was less positive after inhibited responses. Secondly, in the target-locked ERPs task-set switching decreased the P3 at parietal sites, while persisting inhibition from no-go in n-1 was associated with an attenuation of the frontal P3 relative to go in n-1. No impact of task set on the frontal P3 and response mode in n-1 on the parietal P3 was found, suggesting functional dissociation between task set switch and response mode in n-1. Thirdly, exactly the same pattern was observed in the response locked frontal and parietal P3. Fourthly, the task switch related parietal P3 attenuation after targets was also observed in current no-go trials, indicating task and response selection without response execution. No task switch effect on the frontal “no-go P3” was found. In sum, these results suggest that the cue-locked long-lasting P3 reflects task-set updating, whereas the post-target frontal P3 is associated with persisting response inhibition and parietal P3 is related to an after-effect of task-set activation in terms of response selection as it appears both in the target- as well as response-locked ERPs. Furthermore, the post-target parietal P3 effects are most likely due to N2 effects as a more pronounced N2 in switch trials the smaller the P3. A fronto-parietal network for an adaptive control of response requirements and task sets is proposed.