Optimal brain function

A number of strategies we can pursue can help with optimal brain function:

• a stimulating environment involving novelty, requiring continual learning
• brain nutrition (e.g. Omega 3, B6, B12, Zinc, Epicathechin, Folic Acid) and avoiding sugar and bad fats (e.g. trans fatty acids such as you find in margarine).
• brain training (working memory training),
• regular aerobic physical exercise

We can add to this:

• not having chronic stress
• having decent sleep  – e.g. REM (dreaming) sleep is essential for complex learning.

Aerobic exercise

A study I want to look at today came out in the Proceedings of the National Academy of Sciences showing that cognitive health benefits of a regular run. Neuroscientists in Cambridge – a Ph.D friend from the CNBC program among them – recently joined forces with researchers at the US National Institute on Ageing in Maryland to investigate the effect of running on the brain.

They looked at rats’ brains. A lot can be said about how human brains work by looking at the workings of other mammal brains. There are remarkable similarities, and most differences in all but the highest cognitive functions are differences of degree.

They found that running stimulates the brain to grow new neurons – new grey matter – in part of the brain used for spatial memories called the hippocampus. The hippocampus is also critical for our fluid intelligence. Brain tissue taken from the rodents showed that the running mice had grown fresh grey matter during the experiment. Tissue samples from the hippocampus revealed on average 6,000 new brain cells in every cubic millimeter! The hippocampus is one of the few areas of the brain that can grow new neurons throughout adulthood – a process called ‘neurogenesis’.

Cell death in the hippocampus is relatively high as we age – a process called ‘cognitive aging’ -making exercise that much more important for maintaining peak performance as we age.

How it works on memory

“We know exercise can be good for healthy brain function, but this work provides us with a mechanism for the effect” reports my colleague Timothy Bussey, a behavioural neuroscientist at Cambridge.

So what do all these new brain cells do? In their study they found that running – and new cell growth – benefited rats not so much in basic memory tasks such as learning a new object and its location, but in tasks where the objects that were to be remembered were physically identical but could be distinguished based on their spatial relations (e.g. left vs right). The running mice clocked up an average of 15 miles (24km) a day! Their scores on this type of memory test was nearly TWICE as high as those who did no exercise.

It seems that the continual growth of new neurons in the hippocampus ensures that similar events in our experience are encoded uniquely based on their context – in both space and time (x happened after y is a kind of context in time, just like x is to the left of y is a context in space).

This kind of memory translates into our ability to remember what a person had for dinner yesterday and the day before, or where they parked on different trips to the supermarket – exactly the kind of context-dependent memory that is vulnerable to cognitive aging.

Link with fluid intelligence and the HighIQPro ‘dual n-back’ working memory exercise

Recent studies have extended the findings with rats to humans. Running causes the growth of new neurons in the hippocampus in humans at a rate that may be double that of being sedentary.

In the absence of any other intervention, many of these neurons die off (1) . The dual n-back implemented in HighIQPro is a type of focused, attention-demanding and effortful mental training that Curlik and has colleagues have shown can stop this process of cell death of new neuron growth – helping the immature neurons reach maturity and integrate into useful memory circuits.

Fluid intelligence is our on-the-spot reasoning and problem solving ability. It is this kind of advanced short term memory that needs new brain cells for each act of cognition that is needed for fluid intelligence, as this study shows. Curlik and Shors from Rutgers are now promoting the idea of ‘MAP’ training – (M)ental (A)nd (P)hysical training – for a powerful brain fitness intervention.

When I run, I think about everything: physics, family problems, plans for the weekend. I haven’t made any big discoveries on a run, but it does give me time to think through problems. Some solutions are obvious, but they are only obvious when you are relaxed enough to find them.

Wolfgang Ketterle, Nobel prizewinning physicist, MIT

Being a runner, to me, has made being depressed impossible. If ever I’m going through something emotional and just go outside for a run, you can rest assured that I’ll come back with clarity and empowerment.

Alanis Morissette, singer-songwriter