Abstract
We studied cognitive and age-related changes in three task-switching (TS) paradigms: (1) informatively cued TS with go stimuli, (2) informatively cued TS with go and nogo stimuli, (3) non-informatively cued TS with go and nogo stimuli. This design allowed a direct comparison, how informative and non-informative cues influenced preparatory processes, and how nogo stimuli changed the context of the paradigm and cognitive processing in different aging groups. Beside the behavioral measures [reaction time (RT), error rate], event-related potentials (ERPs) were registered to the cue and target stimuli in young (N = 39, mean age = 21.6 ± 1.6 years) and older (N = 40, mean age = 65.7 ± 3.2 years) adults. The results provide evidence for declining performance in the older group: they had slower RT, less hits, more erroneous responses, higher mixing costs and decreased amplitude of ERP components than the participants of the younger group. In the task without the nogo stimuli young adults kept the previous task-set active that could be seen in shorter RT and larger amplitude of cue-locked late positivity (P3b) in task repeat (TR) trials compared to task switch trials. If both go and nogo stimuli were presented, similar RTs and P3b amplitudes appeared in the TR and TS trials. In the complex task situations older adults did not evolve an appropriate task representation and task preparation, as indicated by the lack of cue-locked P3b, CNV, and target-locked P3b. We conclude that young participants developed explicit representation of task structures, but the presence of nogo stimuli had marked effects on such representation. On the other hand, older people used only implicit control strategy to solve the task, hence the basic difference between the age groups was their strategy of task execution.
Highlights
The task-switching (TS) paradigm is a suitable method to study working memory (WM) and cognitive flexibility – psychological processes that are affected by cognitive aging
In Perceptual Reasoning there was no notable difference between groups. These data demonstrate that older participants had higher IQ scores than their peers while the results of young adults were closer to the mean of their age-group
In case of no transformation of their performance, raw scores reveal an evidence that young adults outperformed older participants in 6 of 10 subtests
Summary
The task-switching (TS) paradigm is a suitable method to study working memory (WM) and cognitive flexibility – psychological processes that are affected by cognitive aging. Behavioral studies show that responses of repeat trials are slower in mixed-task blocks (in which two or more task-sets are in operation) compared to single-task blocks (with only one task-set). This difference in reaction time (RT) is the mixing costs (MCs) reflecting higher WM demand on mixed-task. Switching costs (SC) manifest slower responses in switch trials compared to repeat trials in mixed-task blocks and constitute an index of flexibility (see Kiesel et al, 2010 for a review). The reconfiguration of the task-set is required (Rogers and Monsell, 1995), or according to another view, extra time is needed for resolving the interference between the previously active and the current task-set (Wylie and Allport, 2000)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
