Brain Training and IQ – Can You Train Your Brain to Be Smarter?

The Dual N-Back Controversy

The dual n-back task is arguably the most studied and debated brain training exercise in cognitive science. In this task, you simultaneously track a sequence of visual positions and auditory stimuli, and you must indicate when the current stimulus matches the one presented "n" steps back. As you improve, "n" increases, making the task progressively more demanding on working memory.

The controversy began in 2008, when Susanne Jaeggi and colleagues at the University of Michigan published a landmark study in the Proceedings of the National Academy of Sciences showing that participants who trained with the dual n-back task for several weeks showed significant improvements in fluid intelligence (Gf) – the type of intelligence most closely measured by IQ tests. The study made headlines worldwide and sparked enormous interest in brain training.

However, subsequent research has been mixed. Several follow-up studies replicated the finding, but others failed to find any transfer from n-back training to general intelligence. A 2016 meta-analysis by Jacky Au and colleagues, published in Psychonomic Bulletin & Review, analyzed 20 studies and found a small but statistically significant positive effect of n-back training on fluid intelligence measures (an average gain of about 3 to 4 IQ points). Critics point out that many of the positive studies had small sample sizes, lacked active control groups, or may have been influenced by placebo effects and expectancy bias.

A 2017 study by Monica Melby-Lervåg and colleagues, which used stricter inclusion criteria, concluded that the evidence for far transfer (improvement in untrained tasks) was "not convincing." The scientific community remains divided, with the consensus being that while n-back training clearly improves n-back performance, the degree to which it generalizes to broader intelligence is still uncertain.

Lumosity and Commercial Brain Training Apps

Lumosity, one of the most popular commercial brain training platforms, launched in 2007 and quickly attracted over 100 million users with the promise that its games could improve memory, attention, and cognitive speed. Other major players include Elevate, Peak, BrainHQ, and CogniFit.

The scientific evidence for these platforms has been disappointing relative to their marketing claims. In 2016, the Federal Trade Commission (FTC) fined Lumosity's parent company $2 million for deceptive advertising, ruling that their claims about improving cognitive performance, reducing cognitive decline, and helping with conditions like ADHD were not adequately supported by scientific evidence.

That said, the picture is not entirely negative. A large-scale 2015 study published in PLOS ONE found that Lumosity users showed improvement on the trained games but minimal transfer to untrained cognitive tasks. BrainHQ (formerly Posit Science) has somewhat stronger evidence, with studies suggesting improvements in processing speed that persist for years after training. A randomized controlled trial called ACTIVE found that speed-of-processing training (similar to BrainHQ's exercises) reduced the risk of cognitive decline in older adults over a 10-year follow-up period.

The key distinction is between near transfer (improving on tasks similar to the ones you trained on) and far transfer (improving on tasks quite different from your training). Most brain training apps produce robust near transfer but limited far transfer. Getting better at a memory game does not automatically make you better at remembering where you left your keys or solving pattern recognition questions on an IQ test.

What Research Says About Transfer Effects

The concept of "transfer" is central to evaluating brain training. Transfer refers to whether improving on one cognitive task leads to improvement on other, different cognitive tasks.

• Near transfer (well-supported): Training on one type of memory task improves performance on similar memory tasks. Training on specific IQ-style questions improves performance on similar questions. This is why practicing IQ test practice questions reliably improves your score – you are training on tasks very close to the test itself.
• Moderate transfer (some support): Working memory training may modestly improve attention and executive function. Speed-of-processing training can improve performance on timed cognitive tasks. Reasoning training may improve performance on novel reasoning problems if the underlying strategy overlaps.
• Far transfer (weak or inconsistent support): Claims that a brain game will make you "smarter" in general – improving your job performance, academic achievement, or real-world decision-making – are largely unsupported. The most rigorous studies consistently find that improvements are domain-specific rather than general.

A comprehensive 2014 consensus statement signed by over 70 cognitive scientists concluded: "The scientific literature does not support claims that the use of software-based 'brain games' alters neural functioning in ways that improve general cognitive performance in everyday life, or that prevent cognitive slowing and brain disease."

Working Memory Training

Working memory – the ability to hold and manipulate information in your mind over short periods – is strongly correlated with fluid intelligence. This correlation led researchers to hypothesize that training working memory might increase intelligence. The dual n-back studies described above are one example of this approach.

Beyond n-back, other working memory training methods include:

• Complex span tasks: These require you to process information while simultaneously remembering items. For example, solving math problems while remembering a list of words.
• Updating tasks: These require you to continuously update the contents of working memory as new information arrives, such as keeping a running total or tracking changing positions.
• Strategy-based training: Rather than just repeating tasks, some programs teach specific memory strategies like chunking, visualization, and association. These approaches may produce better transfer because they equip you with generalizable techniques.

The current consensus is that working memory training can expand working memory capacity modestly and temporarily, but the degree to which this translates to higher IQ scores or improved real-world cognition remains an active area of research. If you are interested in working memory for IQ test purposes specifically, the most efficient approach is to practice the actual types of questions that appear on IQ tests, including numerical reasoning and logic problems.

Physical Exercise and Brain Health

If the evidence for computer-based brain training is mixed, the evidence for physical exercise is impressively consistent. Regular aerobic exercise is one of the most well-supported interventions for improving cognitive function and protecting brain health.

• Neurogenesis: Aerobic exercise stimulates the growth of new neurons in the hippocampus, a brain region critical for memory and learning. This effect has been demonstrated in both animal and human studies.
• BDNF production: Exercise increases levels of brain-derived neurotrophic factor (BDNF), a protein that supports the survival and growth of neurons and strengthens synaptic connections. Higher BDNF levels are associated with better cognitive performance.
• Improved executive function: A 2019 meta-analysis of 36 studies found that regular exercise significantly improves executive function, including working memory, cognitive flexibility, and inhibitory control – all of which are measured by IQ tests.
• Cardiovascular health: Exercise improves blood flow to the brain, delivering more oxygen and nutrients. This is especially important for maintaining cognitive function as you age.

The type and amount of exercise that produce cognitive benefits appear to be moderate aerobic activity (such as brisk walking, jogging, cycling, or swimming) for at least 150 minutes per week. Even a single 20-minute session of moderate exercise has been shown to temporarily enhance cognitive performance, making it an excellent pre-test activity.

Lifelong Learning and Cognitive Reserve

One of the most reliable predictors of maintaining strong cognitive function across the lifespan is continuous intellectual engagement. The concept of "cognitive reserve" suggests that people who spend their lives learning, reading, solving problems, and engaging in intellectually stimulating activities build a buffer against cognitive decline.

Activities associated with building cognitive reserve include:

• Reading books across diverse subjects
• Learning new skills (musical instruments, languages, programming)
• Engaging in complex occupations that require problem-solving
• Participating in social activities that involve discussion and debate
• Pursuing formal and informal education at any age

While these activities may not dramatically increase your IQ score on any single test, they build the broad knowledge base and flexible thinking habits that support strong cognitive performance over time. Crystallized intelligence – the accumulated knowledge measured by verbal IQ questions – continues to grow throughout your life as long as you keep learning.

Realistic Expectations

Given the research, here is an honest summary of what you can and cannot expect from brain training efforts:

What brain training CAN do:

• Improve performance on the specific tasks you practice (near transfer)
• Familiarize you with IQ test formats, potentially raising your score by 5-10 points through reduced anxiety and increased efficiency
• Modestly improve working memory capacity with sustained, challenging practice
• Provide cognitive stimulation that may contribute to long-term brain health

What brain training CANNOT do:

• Fundamentally change your underlying general intelligence in a matter of weeks
• Produce dramatic, permanent IQ increases from casual use of brain game apps
• Replace the well-established benefits of sleep, exercise, nutrition, and education
• Prevent or cure cognitive disorders like dementia (though it may contribute to cognitive reserve)

The most effective approach to improving your IQ test performance combines several strategies: practice with actual IQ-style questions, maintain a brain-healthy lifestyle, manage test anxiety, and use smart test-taking strategies. Brain training apps can be a small part of this toolkit, but they should not be the centerpiece.

If you want to see where you currently stand, take our free online IQ test. Then use the strategies throughout our site – from practice questions to timing strategies – to prepare for a retest and see how much you can improve.