Training-induced compensation versus magnification of individual differences in memory performance - Lövdén et al. - 2012- Article

There is an ongoing debate about whether or not intelligence equals learning efficiency. The questions is if people with higher intelligence benefit more from training. There are two competing sides in this debate.

Two approaches

Magnification view

This approach looks at the increase in adult age differences after mnemonic training, such as instructions and practice. When people get older, their cognitive abilities and their gains from mnemonic training decline. Also, cognitive abilities are positively related to gains from mnemonic training. These results suggest that individual and age-related differences in gains from cognitive training can be explained by initial differences in cognitive resources that are available.

This approach makes the following three predictions:

• Group differences will be magnified after training (groups starting out higher will gain more).

• Within groups, gains from cognitive training should correlate positively with cognitive abilities, as well as with initial performance.

• The magnitude of interindividual differences increases as a function of training (because differences between the high- and low-performing individuals should be greater after training than at baseline assessment).

Compensation account

According to the compensation account, individuals with good assets are already functioning at the optimal levels, and therefore they have less room to improvement. They already use efficient mnemonic strategies, and they won’t benefit much from being taught another efficient strategy.

This approach makes the following predictions:

• Gains from cognitive training are negatively correlated with cognitive abilities and initial performance.

• Age differences and other interindividual differences are reduced after training.

Flexibility and plasticity

Neither of these two approaches says anything about the conditions under which they may or may not work. This is where we make a distinction between flexibility and plasticity.

Flexibility

Flexibility refers to the capacity to optimize performance within the limits of the brain’s currently imposed structural constraints. It is about the adaptation of a pre-existing behavioral repertoire. The cognitive system has a lot of representational states available, and the brain needs to constantly adapt to environmental demands by assuming such states.

Plasticity

Plasticity refers to the capacity for changes in the possible range of cognitive performance that is enabled by flexibility. It is about the expansion of the existing behavioral repertoire following structural cerebral change.

Based upon this distinction, new predictions can be made concerning the empirical conditions under which compensation or magnification are more likely to occur:

• Performance gains primarily acquired by making use of flexibility are likely to have a pattern that is consistent with the compensation model.

• If extensive training pushes individuals beyond the current range of performance, it induces plasticity. The pattern should then be consistent with magnification, because individual differences in baseline levels of performance and cognitive resources are in part a reflection of past manifestations of plasticity. Under these conditions, baseline performance will be positively related to training gains.

Conclusion

The most important results:

• Between-person differences in associative memory performance decrease after mnemonic instructions.

• Baseline performance within age groups are negatively correlated to instruction gains.

• Age-group differences and between-person differences among children and younger adults increase as a function of extended adaptive practicing.

• Baseline performance and cognitive abilities are positively related to practice gains for children.

This means that the compensation approach matched the pattern of instruction gains, and the magnification approach matched the interindividual differences in practice gains.

Flexibility and plasticity

The results confirm the distinction between flexibility and plasticity. Flexibility is the capacity to optimize the brain’s performance within current structural constraint by using the available range of behavioral states. Plasticity is the capacity for changes in the possible range of cognitive performance enabled by flexibility.

This can also explain why older adults gained more from instructions than children, and why children gained more from practicing than older adults. Because older adults have a larger knowledge base, and are better in shifting to a more effective mnemonic strategy. Children on the other hand have a more plastic associative memory system.