Improving executive control

Improving executive control

Executive control

Executive control refers to the ability to plan, guide and monitor complex goal-directed action. It is a term for the management of the cognitive processes, such as working memory, reasoning, task flexibility, problem solving, planning and execution.

Research on task-switching indicates that there are significant age-differences when it comes to some of these components.

Task-switching

In a task-switching study, participants need to perform two simple tasks, A and B. They do them either in single-task blocks, which means only A or B, or in mixed-task blocks, which means switching between A and B.

There are two types of task-switching costs. Mixing costs is the difference in mean performance between mixed-task and single-task blocks. They say something about the ability to maintain and select two tasks. Switching costs is the difference in mean performance between switch and non-switch trials within mixed-task blocks. They say something about the ability to flexibly switch between tasks.

Previous research

Previous research shows that young adults have smaller mixing costs than children and older adults. Age differences concerning switching costs have not been found. So there is a U-shaped development when it comes to mixing costs, but not for switching costs.

Several studies have shown that with training age-related differences in both types of costs can be reduced. Here, they want to investigate if these training-related improvements in task-switching abilities can be transferred to new switching tasks. Also they examine whether training strategies and the type of task-switching training can modulate this transfer in different age groups.

Executive control training

There are several studies that have shown that executive control training can be transferred to untrained tasks. However, the effects have a high variability and are based on different types of training. Also, the range of transfer distance as well as the age range of the participants was highly variable.

Even though most of the results indicate that transfer is possible in different age groups, it is still not clear which conditions support far transfer, what the differences are between the different types of training and what the lifespan is of the transfer effects.

This research

This study uses the task-switching paradigm. They look at task-set maintenance and selection, and task-set switching. They compared transfer after task-switching training to transfer after training on the same two single tasks performed separately. The study includes two additional training conditions, with which to examine whether specific training strategies or the type of training can modulate transfer. Also, in one of those conditions, they investigated whether verbal self-instruction strategies can be transferred to new, untrained tasks.

In the other condition they examine the effect of the type of task-switching training on the amount of transfer in different age groups. The training was variable. This means that the stimuli and the type of tasks in every training were different.

Results

There was a large transfer of task-switching training to a structurally similar new switching task after training. This means that trainability and transferability of executive control processes are not only being mediated by automatization of single-task components. Unlike previous research, a near transfer of task-switching training on the level of switching costs was also found.

The near transfer on the level of mixing costs was most pronounced in children and older adults. This means that they were able to transfer training-related benefits to a new task.

The amount of near transfer was modulated by the type of training. However, verbal self-instructions did not increase transfer or task-switching training. A possible explanation for that is that the groups that were trained in task switching without verbal self-instructions used an internal verbal strategy which was similar to the self-instructions. Or, if the participants were allowed to verbalize at posttest, and not only during the training, then transfer may also occur.

The different types of training resulted in differential age effects. Adapting to a new task supported the attainment of a generalizable switching skill in adults, but not in children. This is in line with existing literature stating that difficult tasks and stimuli result in higher working memory demands while performing a certain task. Because the working memory capacity in children is more limited than in adults, the children’s performance is more likely to be effected by the increased cognitive load.

Finally, results show broad transfer that was stable, even for different measures of far transfer and to domains that were quite far from the training tasks.