Reactive Control Mode Research Articles

Switching between task control modes incurs greater reprogramming costs than programming the response de novo

When performing synchronous hand and foot movements, the way the limbs are synchronized differs depending on the mode of control. When performed in a reaction time (RT) paradigm (reactive control), EMG onsets become synchronized resulting in asynchronous displacement onset. However, when the same movement is performed as an anticipation-timing task (predictive control), displacement onset is synchronized by unconsciously introducing a small delay between EMG onsets. The present experiment investigated the reprogramming costs associated with switching between predictive and reaction control modes. Participants (N = 12, 6F) were asked to simultaneously lift their right heel and right hand in an anticipation-timing task when a rotating clock hand reached a specified target. On some trials, an auditory stimulus was presented either 250 ms or 500 ms before the target and participants were instructed to execute the synchronous movement as quickly as possible after the signal (i.e., switch to reactive mode). Results showed that when the auditory stimulus was delivered 250 ms before the target, participants were unable to switch to a reactive control mode but did switch when the auditory stimulus was presented 500 ms before the target. As expected, the RT on switch trials was substantially longer (∼230 ms) than a simple RT control condition but was also significantly longer (∼130 ms) than a choice RT control condition. These results indicate that switching between control modes for a task involving the same musculature incurs reprogramming costs that are even greater than the time required to program the response de novo.

The Effects of Posture on Mind Wandering.

Using two executive tasks, we explored how body posture influences mind wandering, a universal internally self-generated activity. Specifically, participants were instructed to perform the Sustained Attention Response Task (SART) and the Flanker task under three postural conditions: lying supine, sitting, and standing upright. These tasks reflect the proactive and reactive modes of executive control, respectively. To measure the frequency of mind wandering, we employed the probe-caught technique, presenting prompts at irregular intervals. The results indicate that, compared to standing and sitting positions, lying supine significantly increased mind wandering, while posture had no effect on either measure of executive control. We suggest that changes in posture alter cognitive activity related to self-generated thoughts and external tasks, whereas the relationship between mind wandering and executive control requires further research.

When stimulus variability accelerates the learning of task knowledge in adults and school-aged children.

Experience with instances that vary in their surface features helps individuals to form abstract task knowledge, leading to transfer of that knowledge to novel contexts. The current study sought to examine the role of this variability effect in how adults and school-aged children learn to engage cognitive control. We focused on the engagement of cognitive control in advance (proactive control) and in response to conflicts (reactive control) in a cued task-switching paradigm, and conducted four preregistered online experiments with adults (Experiment 1A: N = 100, Experiment 1B: N = 105) and 9- to 10-year-olds (Experiment 2A: N = 98, Experiment 2B: N = 97). It was shown that prior task experience of engaging reactive control makes both adults and 9- to 10-year-olds respond more slowly in a subsequent similar-structured condition with different stimuli in which proactive control could have been engaged. 9- to 10-year-olds (Experiment 2B) exhibited more negative transfer of a reactive control mode when uninformative cue and pre-target stimuli, which do not convey task-relevant information, were changed in each block, compared with when they were fixed. Furthermore, adults showed suggestive evidence of the variability effect both when cue and target stimuli were varied (Experiment 1A) and when uninformative cue and pre-target stimuli were varied (Experiment 1B). The collective findings of these experiments provide important insights into the contribution of stimulus variability to the engagement of cognitive control.

Comparative Analysis of the Power Output Capabilities of Grid-Following and Grid-Forming Inverters Considering Static, Dynamic, and Thermal Limitations

This paper investigates the maximum transferable power (MTP) of inverter-based resources (IBRs) and provides the output capability curves (OCCs) of grid-tied grid-following inverters (GFLIs) and grid-forming inverters (GFMIs). To this end, in the first part of the paper, mathematical equations for GFLI static, thermal, and phase-locked loop (PLL)-induced power transfer limits are derived in terms of the grid short-circuit ratio (SCR) and its X/R ratio. Then, considering other operational limitations, such as the IBR AC- and DC-side voltage limits, the OCC of the GFLI is obtained. Additionally, the impact of the reactive current and the reactive control mode on the OCC is further studied, and accordingly, an auxiliary control loop is proposed to maximize the GFLI MTP. In the second part of the paper, a similar approach is employed to derive mathematical equations for GFMI static and thermal limits, and accordingly, the OCC of a GFMI is obtained. The effects of the variation of the voltage set-point of the GFMI on its OCC are then studied, and the superiority of GFMIs compared to GFLIs is shown in terms of the MTP capability. Eventually, several simulation and experimental cases are conducted to validate the obtained equations and OCCs for both grid-following and grid-forming control modes.

Response-Category Conflict and Control Mode Determine Memory Performance for Distractors in a Flanker Paradigm.

Cognitive conflicts can lead to better memory for task-relevant information. However, little is known about memory performance for task-irrelevant information. The present study investigated memory performance of task-irrelevant distractors using a Flanker paradigm. In two experiments (N = 699), participants first completed a study phase with 56 flanker trials. The stimuli consisted of trial-unique pictures. A congruent trial consisted of a target flanked by two identical pictures from the same category (e.g., all mammals). An incongruent trial consisted of a target and flankers from different stimulus categories (e.g., a mammal flanked by two identical birds), which results in a response-category conflict. To explore the impact of different control modes, congruent and incongruent trials were presented in pure blocks (allowing a proactive control mode) or in mixed blocks (requiring a reactive control mode). Afterwards, recognition memory was tested in a surprise memory test. In general, the results showed better memory for congruent than incongruent flankers in pure blocks. In contrast in mixed blocks, the results showed better memory for incongruent than for congruent flankers. Thus, memory performance for distractors varies systematically with response-category conflict and control mode.

On the relationship between emotions and cognitive control: Evidence from an observational study on emotional priming Stroop task.

Evidence is discordant regarding how emotional processing and cognitive control interact to shape behavior. This observational study sought to examine this interaction by looking at the distinction between proactive and reactive modes of control and how they relate to emotional processing. Seventy-four healthy participants performed an emotional priming Stroop task. On each trial, target stimuli of a spatial Stroop task were preceded by sad or neutral facial expressions, providing two emotional conditions. To manipulate the requirement of both proactive and reactive control, the proportion of congruent trials (PC) was varied at the list-wide (LWPC) and item-specific (ISPC) levels, respectively. We found that sad priming led to behavioral costs only in trials with low proactive and reactive cognitive control demands. Our findings suggest that emotional processing affects cognitive processes other than cognitive control in the Stroop task. Moreover, both proactive and reactive control modes seem effective in overcoming emotional interference of priming stimuli.

Reward expectation enhances reactive control of distraction by emotionally negative stimuli.

Reward expectation reduces the interference of task-irrelevant emotional distractors by improving cognitive control. The current study investigated the effects of reward expectation on proactive and reactive cognitive control of negative distractors. Reward expectation (incentive vs. nonincentive trials) was manipulated by a precue signaling the opportunity to gain an extra monetary reward for fast and accurate response on a given trial, followed by the trial display with the response-relevant target stimuli in the periphery and an irrelevant, negative, or neutral distractor in the center. The frequency of negative distractors (high vs. low) was manipulated to induce a proactive or reactive control mode (between-participants factor). Mutilation images and angry faces were used as negative distractors in Experiments 1 (1A and 1B) and 2, respectively. Results revealed performance to be generally facilitated by reward expectation, and impaired by negative (vs. neutral) distractors. Importantly, reward expectation rendered a reduction of negative-distractor interference when observers operated in reactive (vs. proactive) control mode. Moreover, the interaction between reward expectation and cognitive control strategy was modulated by the emotional strength of the negative distractors (mutilation images vs. angry faces). Thus, reward incentive leads to more effective filtering of negative (emotional) distractors when these occur rarely (reactive control) rather than frequently (proactive control), especially with emotionally strong negative distractors. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Distributed bi-level optimal power flow calculation for SVSM interval of integrated transmission and distribution networks considering the uncertain renewables

To accurately and efficiently calculate the static voltage stability margin (SVSM) interval of integrated transmission and distribution networks (ITDNs) considering the uncertain fluctuation of renewables, a distributed bi-level optimal power flow (OPF) calculation method based on the alternating direction method of multipliers for the SVSM interval of ITDNs is proposed in this paper. Due to the different structure characteristics of transmission network (TN) and distribution network (DN), a hybrid node-branch OPF method for calculating the SVSM of ITDNs is proposed, which has better convergence than the traditional node OPF method. Different reactive power-voltage control modes of renewable energy stations (RESs) are also considered in the calculation. Considering the uncertain fluctuation of RESs, two distributed bi-level OPF models for calculating the upper and lower bounds of the SVSM interval of ITDNs are established. Based on the alternating direction method of multipliers, the SVSM interval bounds of ITDNs can be obtained by solving the sub-optimization models and transmitting the boundary coupling variables and the load growth parameter between the TN and multiple DNs iteratively until the given convergence criterion is satisfied. Test results on two ITDNs, the modified IEEE 39–33 & 69 bus system and an actual 2285-bus ITDNs, demonstrate the high computation accuracy and efficiency of the proposed distributed bi-level OPF method compared with other calculation methods.

Prefrontal transcranial direct current stimulation over the right prefrontal cortex reduces proactive and reactive control performance towards emotional material in healthy individuals

The prefrontal cortex plays a crucial role in cognitive processes, both during anticipatory and reactive modes of cognitive control. Transcranial Direct Current Stimulation (tDCS) can modulate these cognitive resources. However, there is a lack of research exploring the impact of tDCS on emotional material processing in the prefrontal cortex, particularly in regard to proactive and reactive modes of cognitive control. In this study, 35 healthy volunteers underwent both real and sham tDCS applied to the right prefrontal cortex in a counterbalanced order, and then completed the Cued Emotion Control Task (CECT). Pupil dilation, a measure of cognitive resource allocation, and behavioral outcomes, such as reaction time and accuracy, were collected. The results indicate that, as compared to sham stimulation, active right-sided tDCS reduced performance and resource allocation in both proactive and reactive modes of cognitive control. These findings highlight the importance of further research on the effects of tDCS applied to the right prefrontal cortex on cognitive engagement, particularly for clinical trials utilizing the present electrode montage in combination with cognitive interventions.

Investigating motor preparation in synchronous hand and foot movements under reactive vs. predictive control.

Synchronizing hand and foot movements under reactive versus predictive control results in differential timing structures between the responses. Under reactive control, where the movement is externally triggered, the electromyographic (EMG) responses are synchronized, resulting in the hand displacement preceding the foot. Under predictive control, where the movement is self-paced, the motor commands are organized such that the displacement onset occurs relatively synchronously, requiring the EMG onset of the foot to precede that of the hand. The current study used a startling acoustic stimulus (SAS), which can involuntarily trigger a prepared response, to investigate whether these results are due to differences in a pre-programmed timing structure of the responses. Participants performed synchronous movements of the right heel and right hand under both reactive and predictive modes of control. The reactive condition involved a simple reaction time (RT) task, whereas the predictive condition involved an anticipation-timing task. On selected trials, a SAS (114dB) was presented 150ms prior to the imperative stimulus. Results from the SAS trials revealed that while the differential timing structures between the responses was maintained under both reactive and predictive control, the EMG onset asynchrony under predictive control was significantly smaller following the SAS. These results suggest that the timing between the responses, which differs between the two control modes, is pre-programmed; however, under predictive control, the SAS may accelerate the internal timekeeper, resulting in a shortened between-limb delay.

The influence of Facebook intrusion and task context on cognitive control.

Social networking sites, especially Facebook, have become increasingly popular over the past decades. However, besides the benefits of using Facebook, negative effects in the form of Facebook intrusion are also increasingly pointed out. Much of the research focuses on personality, emotional and social factors related to Facebook intrusion. However, there has been limited research on the relationship between this type of behavioural addiction and cognitive functioning. Consequently, the current study aimed to verify the relationship between Facebook intrusion and cognitive control in light of the dual mechanism of cognitive control model. Additionally, the study aim was to verify the impact of the Facebook-related context on cognitive control (proactive and reactive modes) compared to neutral and positive contexts. The participants (N = 82 young adults, 57 female, M = 22.24years, SD = 2.67years, age range 18-35years) were divided into two groups based on their level of Facebook intrusion. The Facebook intrusion scale was used to assess the level of Facebook intrusion. The AX-CPT task was used to assess proactive and reactive control modes in three task contexts: Facebook-related, neutral and positive. The current study results show that the participants with high Facebook intrusion had greater reactive control than participants with low Facebook intrusion. The differences between Facebook-related, neutral context and positive context were not found. However, the present findings demonstrate the interaction between Facebook intrusion and task context in cognitive control. More specifically, participants with low Facebook intrusion had greater proactive control than participants with high Facebook intrusion in the Facebook-related and positive context.

Decreased preparatory activation and inattention to cues suggest lower activation of proactive cognitive control among high procrastinating students

Procrastination is a voluntary delay in completing an important task while being aware that this behavior may lead to negative outcomes. It has been shown that an increased tendency to procrastinate is associated with deficits in some aspects of cognitive control. However, none of the previous studies investigated these dysfunctions through the lenses of the Dual Mechanisms Framework, which differentiates proactive and reactive modes of control. The present study was designed to fill this gap, using behavioral and neurophysiological assessment during the completion of the AX-Continuous Performance Task (AX-CPT) by high (HP) and low (LP) procrastinating students (N = 139). Behavioral results indicated that HP (vs. LP) were characterized by increased attentional fluctuations (higher reaction time variability) and reduction in some indices of proactive cognitive control (lower d’-context and A-cue bias, but similar PBIs). Furthermore, the neurophysiological data showed that HP, compared with LP, allocated less attentional resources (lower P3b) to cues that help to predict the correct responses to upcoming probes. They also responded with reduced preparatory activity (smaller CNV) after cues presentation. The two groups did not differ in neural responses linked to conflict detection and inhibition (similar N2 and P3a). Obtained findings indicate that HP might present deficits in some cognitive functions that are essential for effective proactive control engagement, along with preserved levels of reactive cognitive control. In the present paper, we discuss the potential neural and cognitive mechanisms responsible for the observed effects.

The Dual Mechanisms of Cognitive Control Project.

We describe an ambitious ongoing study that has been strongly influenced and inspired by Don Stuss's career-long efforts to identify key cognitive processes that characterize executive control, investigate potential unifying dimensions that define prefrontal function, and carefully attend to individual differences. The Dual Mechanisms of Cognitive Control project tests a theoretical framework positing two key control dimensions: proactive and reactive. The framework's central tenets are that proactive and reactive control modes reflect domain-general dimensions of individual variation, with distinctive neural signatures, involving the lateral pFC as a central node within associated brain networks (e.g., fronto-parietal, cingulo-opercular). In the Dual Mechanisms of Cognitive Control project, each participant is scanned while performing theoretically targeted variants of multiple well-established cognitive control tasks (Stroop, cued task-switching, AX-CPT, Sternberg working memory) in three separate imaging sessions, that each encourages utilization of different control modes plus also completes an extensive out-of-scanner individual differences battery. Additional key features of the project include a high spatio-temporal resolution (multiband) acquisition protocol and a sample that includes a substantial subset of monozygotic twin pairs and participants recruited from the Human Connectome Project. Although data collection is still continuing (target n = 200), we provide an overview of the study design and protocol, along with initial results (n = 80) revealing evidence of a domain-general neural signature of cognitive control and its modulation under reactive conditions. Aligned with Don Stuss's legacy of scientific community building, a partial data set has been publicly released, with the full data set released at project completion, so it can serve as a valuable resource.

Impact of converter interfaced generators on power system long-term voltage stability monitoring and control

This paper investigates the impact of power-electronic Converter Interfaced Generators (CIG) connected at the distribution network on bulk power system long-term voltage stability. In particular, the CIG effect on instability onset, on-line stability monitoring and protection against voltage collapse is examined using an IEEE Test System properly modified to include significant CIG penetration. Several simulations are executed to evaluate the CIG impact on instability onset and determine the performance of a voltage instability monitoring method, as well as of three protection scheme variants. Different CIG connection topologies, as well as reactive control modes are examined. Conclusions drawn show significant impact of CIGs and demonstrate the need for specific countermeasures design that account for CIG interaction with traditional protection measures.

Can a Theater Acting Intervention Enhance Inhibitory Control in Older Adults? A Brain-Behavior Investigation.

Purpose: Studies of reactive and proactive modes of inhibitory control tend to show age-related declines and are accompanied by abnormalities in the prefrontal cortex. We explored which mode of inhibitory control would be more amenable to change and accrue greater benefits following engagement in a 4-week theater acting intervention in older adults. These gains were evaluated by performance on the AX-CPT task. We hypothesized that an increase in proactive control would relate to an increase in AY errors and a decrease in BX errors. In contrast, an increase in reactive control would be associated with a decrease in AY errors, no change in AY reaction time, and an increase in BX response time. Further, we posited that an increase in behavioral proactive control would accompany greater cue versus probe activity for previously identified regions in the prefrontal cortex. In contrast, an increase in behavioral reactive control would be accompanied by greater probe activation in these identified brain areas.Materials and Methods: The participants were 179 community-dwelling adults aged 60–89 years who were on average, college-educated. Participants were pseudo-randomly assigned to either an active-experiencing acting intervention condition (n = 93) or the active control condition (n = 86); participant assignment was subject to time of enrollment. Participants in both groups were trained by theater-actor researchers with expertise in acting interventions. In contrast to the active control participants who attended a course on theater acting, the acting-intervention group was required to consistently deploy proactive and reactive control mechanisms. Both groups met two times/week for 75-min for 4 weeks. Participant brain-behavioral performance on the AX-CPT task was evaluated prior to and after this four-week period.Results: No intervention effects were found in favor of proactive control. Behavioral evidence in favor of reactive control was weak. Brain-related benefits to reactive control was illustrated by greater probe-activation in Brodmann areas 6 and 8, relative to controls and pre-intervention.Conclusion: We found some evidence for improvements in reactive control via brain measures, attributed to engagement in the acting intervention.

An Examination of the Relationships between Dohsa-hou and Cognitive Control: Differential Contributions for Proactive and Reactive Control Modes in Body Movement Attention and Execution

An Examination of the Relationships between Dohsa-hou and Cognitive Control: Differential Contributions for Proactive and Reactive Control Modes in Body Movement Attention and Execution

Proactive and reactive control mechanisms in navigational search.

Reactive and proactive cognitive control are fundamental for guiding complex human behaviour. In two experiments, we evaluated the role of both types of cognitive control in navigational search. Participants searched for a single hidden target in a floor array where the salience at the search locations varied (flashing or static lights). An a-priori rule of the probable location of the target (either under a static or a flashing light) was provided at the start of each experiment. Both experiments demonstrated a bias towards rule-adherent locations. Search errors, measured as revisits, were more likely to occur under the flashing rule for searching flashing locations, regardless of the salience of target location in Experiment 1 and at rule-congruent (flashing) locations in Experiment 2. Consistent with dual mechanisms of control, rule-adherent search was explained by engaging proactive control to guide goal-maintained search behaviour and by engaging reactive control to avoid revisits to salient (flashing) locations. Experiment 2 provided direct evidence for dual mechanisms of control using a Dot Pattern Expectancy task to distinguish the dominant control mode for a participant. Participants with a reactive control mode generated more revisits to salient (flashing) locations. These data point to complementary roles for proactive and reactive control in guiding navigational search and propose a novel framework for interpreting navigational search.

Social exclusion modulates dual mechanisms of cognitive control: Evidence from ERPs.

Many studies have investigated how social exclusion influences cognitive control but reported inconsistent findings. Based on the dual mechanisms of control framework, this study investigated how social exclusion influences proactive and reactive modes of control (Experiment 1) and the underlying mechanisms (Experiment 2). The Cyberball game was used to manipulate social exclusion. Eighty‐six female participants (about 40 for each experiment) performed cognitive control tasks while event‐related potentials were recorded. In Experiment 1, an AX Continuous Performance Task (AX‐CPT) was adopted to differentiate between proactive and reactive control. Results showed that social exclusion weakened proactive control but enhanced reactive control, as reflected by the weaker proactive control indicators (i.e., P3b and CNV), but strengthened reactive control indicators (accuracy and N2) in excluded individuals. More importantly, in Experiment 2, through varying in whether task cues were available before or after target onset in a cued‐flanker task, we further manipulated the possibility of engaging proactive control, and found the weakened proactive control could be attributed to both impaired cognitive ability and lowered motivation to engage proactive control in excluded individuals. Together, these results provide insight on how social exclusion influences cognitive control and suggest promising implications for designing effective interventions to relieve the negative impact of social exclusion.

Dohsa-hou Enhanced Cognitive Control: Focusing on Proactive and Reactive Cognitive Control Mode

Dohsa-hou Enhanced Cognitive Control: Focusing on Proactive and Reactive Cognitive Control Mode

Proactive and reactive modes of cognitive control can operate independently and simultaneously

Cognitive control enables optimal biasing of attention, perception, and actions in the service of mental or behavioral goals. To understand the variability of applied cognitive control, we need to unravel the relation between two underlying mechanisms: proactive and reactive modes. During proactive cognitive control, goal-relevant information is selected before the occurrence of a cognitively demanding event, and is actively maintained for as long as required by the task. During reactive mode, cognitive control is transiently activated only after the cognitively demanding event has occurred. Mechanistically, proactive and reactive control modes may be at least semi-independent and engaged simultaneously, but this has so far not been demonstrated empirically. Situational demands and an individual's cognitive capacity and motivation may bias behavior towards one or the other mode. Reward induces more proactive processing in the AX-CPT task, whereas context load induces reactive processing. We combined these manipulations to investigate the extent to which proactive and reactive control modes can operate independently and simultaneously. The results replicated already published effects of reward incentives and context load. Most importantly, these effects were essentially independent of each other, suggesting that proactive and reactive cognitive control modes depend on separate information-processing and neural mechanisms. The results also show that while proactive processing is influenced by reward, reactive processing seems independent of such factor. These findings have implications for our understanding of the structure of cognitive control and cognitive motivation, and are relevant for the design of interventions to improve cognitive control in various developmental and neuropsychiatric groups.