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In task switching, an interaction between task and response is often observed, with response repetition (RR) benefits in task‐repeat trials and RR costs in task‐switch trials. The theoretical accounts of the RR effect remain controversial, and neuroscience evidence is scarce. The present study utilized the event‐related potentials (ERPs) method to explore the neural mechanism underlying the RR effect by adopting a cued task‐switching paradigm. The ERP results revealed the interaction between task and response in the P3b time window, with a response switch positivity under task‐repetition conditions and an RR positivity under task‐switching conditions. In addition, there were RR positivity in the N2 irrespective of task transition and in the late component (LC, 550–600 ms) that only under the task repetition condition. On the individual level, the RR benefit positively correlated with the RR positivity in the LC, while the RR costs negatively correlated with RR positivity in the N2/P3 component. These results suggest that both response reconfiguration and episodic‐retrieval make contributions to the RR effects, which were also discussed in terms of predictive model for a domain‐general inference and learning of perceptual categories. [ABSTRACT FROM AUTHOR]

Highlights • The hierarchical effect appeared earlier than the shift effect. • High-shift evoked larger P3 and LPC amplitudes than low-shift. • High-shift needed more cognitive demanding in rule reconfiguration and selection. • The ERP results mainly reflected the process of rule learning. ABSTRACT Previous studies on task or rule shifting have shown that the switch cost is affected by the hierarchical level of abstraction. The present study aimed to explore the neural correlates of hierarchical modulation in rule shifting. Participants were required to respond to number stimuli (1–9, excluding 5) while adhering to alternative rules cued by different perceptual features of the stimuli. Across trials, the rules might repeat or shift at either high or low hierarchical levels. Behavioral results indicated that the reaction times were significantly slower in the high-shift than in the low-shift condition. The electrophysiological results revealed (1) significant difference in P300 between high- and low-shift conditions, with larger P300 in the high-shift condition; and (2) increased amplitude of the late positive component (LPC) elicited by the high-shift condition as compared to that by the low-shift condition. These findings demonstrate that the task-set reconfiguration and rule selection is more difficult for higher hierarchical level of rule shifting as compared with lower level. [ABSTRACT FROM AUTHOR]

Numerous studies have explored the neural mechanisms related to task switching or rule shifting, but few have revealed the neural substrates related to rule shifting at different hierarchical levels. The purpose of this study is to explore the different event-related potentials (ERPs) elicited by higher and lower hierarchical levels of rule shifting in a cue-target task. In the task, participants were presented with Arabic digits (1–9, excluding 5), and performed a parity or magnitude judgment according to the preceding cues, a letter R. The rules were constructed in a hierarchical set, and the rule was either repeated or shifted between neighboring trials. Importantly, the rule shifting would be at a higher or lower hierarchical level. The results showed that, for the cues, the higher hierarchical shifting evoked increased P2, P3, late positive component (LPC), and decreased N2 relative to lower hierarchical shifting, reflecting the increased demand in selective attention, rule processing, and proactive control during the rule acquisition stage. For the targets, the hierarchical effects were reversed, and emerged later than the rule shift effect. These findings imply that, in the cue-target rule-shifting task, the brain responds differently to different hierarchical levels of rule shifting. [ABSTRACT FROM AUTHOR]

The distinction between task-switching (T-switch) and response-rule switching (RR-switch) has been reported in previous studies. However, it is unclear whether the neural correlates of proactive and reactive control differ between T-switch and RR-switch. In this study, a modified cue-target task was adopted. When the cue in the current trial differed from that in the preceding trial in shape (or color), the participants had to perform a T-switch (or RR-switch). Otherwise, they performed the same task following the same response rule. The behavioral results showed that the switch cost was greater for the RR-switch than for the T-switch. The event-related potential results indicated that (1) for cues, the switch-positivity in the late positive component (LPC) (500–800 ms) was more enhanced for the RR-switch than for the T-switch over the central to parietal regions, reflecting increased proactive control for the RR-switch compared with the T-switch; (2) for targets, the P3 amplitude was more attenuated in the RR-switch than the T-switch over the central and parietal regions, reflecting increased reactive control for the RR-switch; and (3) under the T-switch, the switch-positivity in the cue-LPC was negatively correlated with accuracy cost, while under the RR-switch, the switch negativity in the target-P3 was positively correlated with the reaction time cost. These findings suggest that similar proactive and reactive control are recruited in the T-switch and RR-switch, whereas cognitive control efforts clearly differ between them, perhaps due to different sub-processes. • Task switching (T-switch) and response rule switching (RR-switch) are compared. • Switch cost is greater in RR-switch than in T-switch. • Cue-LPC was larger in RR-switch than for T-switch. • Target-P3 was decreased in RR-switch than in T-switch. • Cognitive control differs between T-switch and RR-switch. [ABSTRACT FROM AUTHOR]

• A nested hierarchical task was used to investigate the asymmetrical switch cost. • Longer reaction time was found in upward switch than in downward switch. • A larger N2 was elicited by upward switch than downward switch. • Sustained potential was more negative for upward switch. • Our results are in accordance with task-set reconfiguration theory. Numerous studies have investigated asymmetric switch cost between different types of tasks. However, the underlying neural mechanism of asymmetric switch cost in a hierarchical task remains unknown. In the present study, we used a representation-nested paradigm and defined three hierarchical levels of number comparison. Participants were required to switch between different levels according to the color of the stimuli. Behavioral result showed a longer response time in the upward switch (from the lower level to the middle level) than in the downward switch (from the higher level to the middle level). The event related potential results showed that (1) a larger N2 was elicited by the upward switch, which reflects the response inhibition process; and (2) the sustained potential component was most negative for the upward switch and least negative for the repeat condition, thereby reflecting the different degrees of reconfiguration of task set. The reverse asymmetric switch cost in the hierarchical task was explained using task-set reconfiguration theory and related to the activation of the left frontal region. [ABSTRACT FROM AUTHOR]