Training and Transfer of Cue Updating in Older Adults Is Limited: Evidence From Behavioral and Neuronal Data

Abstract

Cognitive control processes, such as updating task-relevant information while switching between multiple tasks, are substantially impaired in older adults. However, it has also been shown that these cognitive control processes can be improved by training interventions, e.g., by training in task switching. Here, we applied an event-related potential (ERP) approach to identify whether a cognitive training improves task-preparatory processes such as updating of relevant task goals. To do so, we applied a pretest-training-posttest design with eight training sessions. Two groups of older adults were either trained in task switching (treatment group) or in performing single tasks (control group) and we compared their performance to a group of untrained younger adults. To foster cue updating in the treatment group, we applied a cue-based switching task in which the two task cues were randomly selected prior to target presentation so that participants had time to prepare for the upcoming task. In contrast, the control group also received task cues but those were redundant as only one task had to be performed. We also examined whether training in cue updating during task switching can be transferred to a similar cognitive control task measuring updating of context information, namely a modified version of the AX-Continuous Performance Task (AX-CPT). The results revealed training-specific improvements in task switching, that is, a larger improvement in blocks requiring switching in comparison to single tasks at the behavioral level. In addition, training specific-effects were also found at the neuronal level. Older adults trained in cue updating while switching showed a reduction in mixing costs in the cue-related P3, indicating an improvement in preparatory updating processes. Additionally, P3 topography changed with training from a very broad to a parietally focused scalp distribution similar to the one found in younger adults. However, we did not obtain training-specific improvements in context updating in the AX-CPT neither at the behavioral level nor at the neuronal level. Results are discussed in the context of the ongoing debate on whether transfer of cognitive training improvements is possible.

Keywords: Cue-P3; cue updating; older adults; task-switching training; transfer.

Figure 1

Cue-locked ERPs for single, repeat, and switch trials at pretest for younger adults, older adults in the single-task training, and older adults in the task-switching training group displayed at electrodes Fz, Cz, and Pz.

Figure 2

Cue-locked ERPs for context-independent and context-dependent trials at pretest for younger adults, older adults in the single-task training group, and older adults in the task-switching training group displayed at electrodes Fz, Cz, and Pz.

Figure 3

Mixing costs (left) and switching costs (right) on the level of mean RT as a function of group and session. Error bars refer to standard errors of the mean.

Figure 4

Cue-locked ERPs in single, repeat, and switch trials at posttest for younger adults, older adults in the single task training group, and older adults in the task-switching training group displayed at electrodes Fz, Cz, and Pz.

Figure 5

Mixing costs (calculated as the difference between single trials and the mean of repeat and switch trials) in early cue-locked P3 amplitudes at electrode Pz for pre- and post-test. Smaller values reflect smaller mixing costs. Error bars refer to standard errors of the mean. Mixing costs seem to decrease from pre- to post-test for younger adults and older adults from the task-switching training group, while they show a tendency to increase for older adults from the single-task training group.

Figure 6

Context effects (c-dep–c-indep) on the level of mean RT as a function of group and session. Error bars refer to standard errors of the mean.

Figure 7

Cue-locked ERPs for context-dependent and context-independent trials at posttest for younger adults, older adults in the single-task training group, and older adults in the task-switching training group displayed at electrodes Fz, Cz, and Pz.