On one side of the argument is a long-seated view based on our basic scientific understanding of the brain.

On the other are the many inspiring recoveries achieved by brain injury patients around the world beyond two years.

In America, the fabled two-year window still divides opinion, says Dr Kihwan Han (pictured),
 a research scientist at the Center for Brain Health at the University of Texas in Dallas. He believes it has never been definitively challenged by science because of a gap 
in focus.

“The neuroscience community are doing research into the acute stage of brain injury and believe it is hard for the brain to recover.

“Neuro-rehab people are more focused on outcomes and how people can do better, however.

“There has been a lack of interest in identifying changes to the brain and quantitatively measuring the ongoing impact of treatment on the brain itself.”

A new study headed up by Dr Han gives neuroscientists the numbers they need to believe in long-term brain injury recovery.

It shows that certain types of brain training can cause structural changes in the brain and new neural connections several years after a traumatic brain injury (TBI).

Both cortical thickness and neural network connectivity can increase as a result of instructor-led training.

The findings offer a way of quantifying the power of neuro-rehab treatment that has not previously been explored.

Han, whose research was published in
 the Brain and Behavior journal, says: “A
 TBI disrupts brain structure. These brain changes can interfere with brain network communication and the cognitive
 functions that those networks support.

For people with chronic TBI, they may have trouble with daily tasks such as creating shopping lists or resolving conflicts with others, for many years after the injury.

These findings provide hope for people who thought, ‘this is as good as my recovery is going to get’ and for the medical community who have yet to find a way to objectively measure a patient’s recovery.”

The study included 60 adults with TBI symptoms lasting an average of eight years. They were randomly placed into one of two cognitive training groups; strategy-based training or knowledge-based training.

Over an eight-week period, the strategy-based training group learned strategies to improve attention and reasoning.

The knowledge-based training group learned information about the structure and function of the brain as well as the effects of sleep and exercise on brain performance.

Magnetic resonance imaging measured cortical thickness and resting-state functional connectivity (rsFC) before training, after training and three months post-training.

Previous studies have shown that cortical thickness and rsFC can be potential markers for training-induced brain changes.

Individuals in the strategy-based reasoning training showed a greater change in cortical thickness and connectivity compared to individuals who received the knowledge-based training.

Han says: “Strategy is an effective way of improving thought processes.
 It helps people to organise their thoughts to achieve certain tasks.

“Our study shows how different types of training can affect the brain in different ways, but it doesn’t necessarily mean knowledge-based training has no purpose.

“We identified changes to the brain with knowledge training too, but strategy made more of a difference.”

Changes in cortical thickness and functional connectivity also correlated to an individual’s ability to switch between tasks quickly and consistently to achieve a specific goal.

“The range of cortical thickness change 
was really tight, at about half a 
millimetre, but the range of improvement 
to people’s performance was significant,” says Han. 
”People who showed the greatest change
 in cortical thickness and connectivity, showed the greatest performance increases in cognitive tasks.

“Perhaps future studies could investigate the added benefit of brain stimulation treatments in combination with cognitive training for individuals with chronic TBI who experience problems with attention, memory or executive functions.”

Han believes being able to quantify the power of treatment on the brain could challenge approaches to neuro-rehab in the future.

“Rehab professionals have often wondered why we scientists care about the brain changing through training.

“Conventional manuals report on less precise ways of measuring treatment efficacy. But these findings mean we could optimise the impact of training on patients [by measuring it scientifically].”

According to the UK Acquired Brain Injury Forum (UKABIF), the two-year recovery window cannot simply be dismissed as 
a myth.

Most significant improvements after brain injury do occur within the first 24 months. But UKABIF estimates that around a third of brain injury patients continue to improve after the initial two years.

Han’s study presents an interesting way of quantifying the results of rehab and offers hope to people living with the effects of an historic brain injury.

From a neuro-rehab perspective, however, it raises several unanswered questions. Among them is how instructor-led training could be delivered to people that might have ended their rehab journey several years ago?

Also, would such treatment deliver the meaningful and practical improvements needed to justify its cost and resources? Hopefully further studies will build on the promising progress Han has made so far.


Brain training: Silver bullet or fool’s gold?

Dr Kihwan Han’s study shows tangible proof that brain training works – if delivered by a professional instructor.

Self-administered brain training, however, is struggling to conclusively prove its worth.

The concept of brain training is nothing new but surged to prominence in the last decade with the dawn of games on handheld devices such as Nintendo DS and mobile phone apps.

The idea that a few hours of play can enhance your brain power is certainly appealing, especially to older generations in a consumer world dominated by anti-ageing potions, lotions and therapies.

Yet a study at the University of Pennsylvania has found brain training computer games do not make users any cleverer.

The researchers defined intelligence as the ability to make less impulsive and more future oriented decisions – a common trait in people with strong cognitive abilities.

This stems from tests involving choices between immediate smaller rewards and delayed larger rewards.

Researchers also knew that this behaviour is likely to be mediated by a set of brain structures in the dorsolateral prefrontal area of the brain – areas that have been linked to performance on executive function tasks like those featured on the Lumosity brand of brain training games that was used in the study.

Co-lead researcher Joseph Kable said: “The logic would be that if you can train cognitive abilities and change activity in these brain structures, then that may change your likelihood of impulsive behaviour.”

The researchers recruited two groups, each with 64 healthy young adults. One group
was asked to follow the Lumosity regimen, performing the executive function games 
for 30 minutes a day, five days a week for 10 weeks.

The other group followed the same schedule but played online video games instead. Both groups were told that the study was investigating whether playing online video games improves cognition and changes one’s decision-making.

The researchers found that the training didn’t induce any changes in brain activity or decision making during these tasks.

The participants were also asked to complete a series of cognitive tests that were not part
of the training to see if the program had any effect on their general cognitive abilities.

While both groups showed improvement,
the researchers found that commercial brain training did not lead to any more improvement than online video games.

Furthermore, when they asked a no-contact group, which didn’t complete commercial brain training or video games, to complete the tests, the researchers found that the participants showed the same level of improvement as the first two groups, indicating that neither brain training or online video games led to cognitive improvements beyond likely practice effects.

Kable said: “I think we’d all like to have better cognitive abilities and we all see ways in which the vagaries of where we grew up and what school we went to and who our parents were had these effects on learning at an early age.

“The notion that you could do something now that would remediate it was very exciting. I think it was just an idea that really needed to be tested.”

A much more positive assessment of brain training was published by Cambridge University recently.

It investigated the use of brain training by people with amnestic mild cognitive impairment (aMCI) – the transitional stage between healthy ageing and dementia.

It is characterised by day-to-day memory difficulties and problems of motivation. Cognitive training has shown some benefits, such as speed of attentional processing, for patients with aMCI, but training packages
are typically repetitive and boring, affecting patients’ motivation.

To overcome this problem, researchers from the Departments of Psychiatry and Clinical Neurosciences and the Behavioural and Clinical Neuroscience Institute at the University of Cambridge developed Game Show, a memory game app, in collaboration with patients with aMCI, and tested its effects on cognition and motivation.

The researchers randomly assigned 42 patients with aMCI to either the cognitive training or control group.

Participants in the cognitive training group played the memory game for eight one-hour sessions over a four-week period; participants in the control group continued their clinic visits as usual.

The results showed that patients who
played the game made around a third fewer errors and improved their memory score
by around 40 per cent, showing that they 
had correctly remembered the locations of more information at the first attempt on a
test of episodic memory.

Episodic memory is important for day-to-day activities and is used, for example, when remembering where we left our keys in the house or where we parked our car in a multi-story car park.

Compared to the control group, the cognitive training group also retained more complex visual information after training.