Not inertia but reconfiguration: Asymmetric switch cost in a hierarchical task

• Published in: Brain research 2019-10, Vol.1720, p.146291-146291, Article 146291
• Main Authors: Li, Junchen, Cao, Bihua, Han, Jiahui, Xie, Liufang, Li, Fuhong
• Format: Article
• Language: English
• Subjects: Asymmetric switch cost; Hierarchical representation; Hierarchical switch; Task-set reconfiguration
• ISSN: 0006-8993; 1872-6240
• DOI: 10.1016/j.brainres.2019.06.010

•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.