“Smarter, sharper, and brighter” is what websites like Luminosity.com promise about the effectiveness of their computer-based brain-training programs, which potential for low-cost and reliable measurement of performance has attracted more than 50 million of users. Independent studies on brain-training services provide (at best) equivocal support for their effectiveness . Before analyzing any of this evidence (or paying any expensive subscription), it is essential to understand the variables that are involved in brain-training: target populations, evaluation methods, time frames, and generalizability.
In the first place, intuitively, healthy young adults will not respond in the same way to brain-training interventions than older adults with cognitive impairment, or sufferers of brain injury. Most studies select a target population to focus, and each of these groups need to be taken into account when evaluating the scientific literature. So far, evidence suggests that brain games are exclusively useful for the elderly .
In the second place, there is no single measure of intelligence or brain function. The factor “G” is rather an abstract and theoretical concept, that typically consists of: (1) Memory. The ability to encode, store, and recall information, in a verbal, visual, or episodic way. Each memory type is related to specific tasks that reflect each memory functions. So far, no evidence of intelligence improvement after working memory training has been shown . (2) Attention, as the capacity to focus one’s perception on target visual or auditory stimuli and filter outcomes irrelevant distractions. (3) Executive function. The ability to strategically plan and change one’s actions as demanded. (4) Reaction time, or processing speed, which deal with how quickly you can reason. In contrast to memory, some researchers argue that attention, executive function, and reaction time can be indeed enhanced by brain games, particularly in children .
In the third place, studies need to contend the duration of any training effect. If there is one, how long does it last? Unfortunately, this study has been found that the cognitive benefits after brain training in the elderly disappeared after a 3-month interval , suggesting that cognitive plasticity
can be induced in older adults by training, but to maintain the benefits periodic boosting sessions would be necessary.
Finally, what most of us are interested in: generalizability. I am guessing that what users of luminosity.com are looking for it is not precisely getting better at the games themselves, but to enjoy the benefits of them in their every-day life. To what extend does training myself in the Stroop Test increase performance on other tasks, like programming, designing, or doing math? Not surprisingly, existing research is just scratching the surface of addressing all the potential of this question: in this study, although improvements were observed in every one of the cognitive tasks that were trained, no evidence was found for transfer effects to untrained tasks, even when those tasks were cognitively closely related
In conclusion, existing research does not address all the variables involved in brain-training interventions appropriately. However, there seems to be some recognizable patterns in the data, making the field promising . Even though there is little empirical reason to believe that a training improves one skill in particular by generalizability, these games are likely to make you feel more motivated towards cognitive enhancement, and are a safe “thermometer” for your nootropics usage.