03/21/2012 04:56 pm ET | Updated May 21, 2012

Personality Influences on Cognitive Training

Cognitive training works. But does it work equally well for all people?

A new study suggests that the effectiveness of working memory training depends heavily on personality. Barbara Studer-Luethi and her colleagues focused on two personality traits in particular: neuroticism and conscentiousness. Neurotic people are anxious and emotionally unstable, whereas conscientious folks are persistent, hardworking, and self-disciplined. How are these traits related to cognitive training?

The researchers had 47 Chinese participants engage in working memory training for four weeks (as a control condition, they also included 43 students who didn't receive any training). The training task they used was the n-back task, which is commonly used in research on working memory and intelligence. The researchers administered two different versions of this task.

In their more difficult version, the dual n-back task, participants saw a sequence of blue squares appear at one of eight different locations while also listening to a series of eight letters on their headphones. Participants were told to indicate when the current stimulus was the same as the one a certain number of positions back in the sequence. After each block of trials (there were 15 blocks in total), they received feedback about their working memory. Difficulty level was then adjusted based on their performance.

The researchers also administered an easier version of the n-back task, called the single n-back task. This version was a piece of cake compared to the other version, since it only required processing visuospatial stimuli. There was no auditory input in this version, so there was no multitasking, and therefore much less interference.

It's one thing to show working memory increases ("near transfer"), but it's much more powerful to show that the increases actually generalize to something important ("far transfer"). To check for far transer, they also administered a few measures of fluid intelligence, which required looking at a matrix of figures and completing a pattern. This is an excellent measure of on-the-spot abstract reasoning ability. What did they find?

First, they noticed there were no baseline differences in working memory or fluid intelligence based on personality. This is really important, because it means their results cannot be explained by preexisting differences in cognitive functioning.

Then they looked at the effect of personality on cognitive training. While participants scoring higher in neuroticism showed lower training scores overall, an analysis of the different working memory tasks was more informative. Neurotic participants reported less enjoyment in the more difficult, dual n-back task, and also showed less gains based on their training (for both far and near transfer). Results differed for the easier, single n-back task. In this version of the working memory task, neurotic participants showed more gains in far transfer. According to the researchers, these findings suggest that the multi-tasking nature of the dual n-back task may have caused the neurotic participants to short-circuit, due to their higher activation levels! In the easier version, however, the neurotic participants' higher levels of activation may have been an advantage, allowing them to maintain their concentration and vigilance.

So that's neuroticism. What about conscientiousness? Participants with higher levels of conscientiousness reported greater enjoyment in the working memory training and also showed better overall training performance. This is not that surprising, since the conscientious participants were probably more motivated to succeed than the less conscientious participants. But this is where things get interesting: the enjoyment and training benefits seemed to be much stronger in the easier version of the working memory task. And in terms of transfer effects, conscientiousness was much more related to near transfer than far transfer.

The researchers speculate:

[O]n one side, the conscienious participants may have developed effective but highly-specific strategies, which brought them success in the training and the near transfer tasks, but did not foster far transfer processes. On the other side, the increased self-attention of conscientious subjects, namely their higher evaluation apprehension, the overestimation of the importance of their performance as well as their tendency to be self-deceptive, may have detracted mental resources, which would have been necessary for an efficient transfer process to higher cognitive abilites.

This research suggests that both personality traits -- neuroticism and conscientiounsess -- are relevant to cognitive training. Neurotic people are too busy worrying and ruminating, and conscientious people are too concerned with perfoming well, that neither personality types are bringing their full attention and mental resources to the task. In certain contexts, though, either trait can be an advantage. For instance, when a task doesn't involve multitasking, the hypervigilance that comes with neuroticism may be helpful during working memory training, and can even generalize to more general fluid reasoning skills. The key is to avoid overstimulating the neurotic person. Based on these results, cognitive training interventions may want to take into account individual differences in personality for optimal effectiveness.

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