Food for thoughts – the impact of food on learning

According the latest government statistics obesity is on the rise, there is also a link to Covid deaths with nearly 8% of critically ill patients in intensive care being obese, compared with 2.9% of the general population. The WHO has stated that being overweight and obese is the fifth leading risk for global deaths with at least 2.8 million adults dying each year.

Eating too much is clearly not good for your health but how about what you eat, how might that impact your health, in particular your brain?

Viva las Vagus

Have you ever used your gut instinct, had butterflies in your stomach or when feeling nervous had to rush to the toilet? If so then you already have some evidence of the connection and importance of your gut to the way you think and feel. The vagus nerve is the longest cranial nerve and runs from the brain stem to part of the colon in effect making the connection. The biggest influence on the levels of activity of the vagus nerve are the trillions of microbes that reside in the gut. The vagus nerve is able to sense the microbe activity and effectively transfer this gut information to the nervous system and ultimately the brain. Watch this 2-minute video that shows how this works.

Scientists refer to the relationship between the gut and the brain as the “gut brain axis”. The brain sends chemical signals to the gut through the bloodstream, one such example is the feeling of being full or hungry. But and this is the interesting part – the stomach talks back; gut bacteria send messages in the same way the brain communicates using neurotransmission. Prior blog – The learning brain.

Exactly what the messages say depends on what you eat, a gut filled with fruit and vegetables will have different microbes to one that has just consumed a Big Mac. This is a very new area and most of the research has been completed on rats but there is already some evidence to suggest that junk food impairs memory.

Hopefully this gives you some idea as to the strong connection that exist between your stomach and your brain. We can now move on and consider what specific types of foods can help when learning.

These Ted talks are well worth watching if you want to find out more – Your Gut Microbiome: The most important organ you’ve never heard of (11m), and Mind-altering microbes: How the microbiome affects brain and behaviour (6m).

What to eat when studying

The first thing to say is that I am far from an expert on nutrition and so the focus here is more on the impact food has on mood, concentration, cognition and memory. Secondly, to give this some context it might be worth thinking about what you eat in the same way an athlete does. They pay close attention to their diet to make sure their body is in the best possible condition in order to compete because if not they are reducing their chances of success. However, a good diet is no substitute for the hard work they have to put in at the gym, you have to do both. Short video on how nutrition is key to sports performance.

Brain foods

  1. Apples, berries and Citrus – The British Journal of Nutrition published research in 2010 (The impact of fruit flavonoids on memory and cognition) indicating that consuming certain fruits such as berries, apple and citrus, that are rich in flavonoids can help improve memory and cognition.
  2. Dark chocolate – Research published in the Frontiers in Nutrition (Enhancing Human Cognition with Cocoa Flavonoids) found that dark chocolate which also contains flavonoids improved memory in both the short and long term. But remember many types of chocolate are high in sugar, fats, and calories so it’s not all good news.
  3. Rosemary – Northumbria University’s Department of Psychology found that herbs such as rosemary and lavender impacted memory, with the scent of rosemary enhancing memory but lavender impairing it. Maybe Shakespeare knew what he was talking about when he said ‘rosemary is for remembrance’.
  4. Oily fish and walnuts (omega 3) – There is a much-published connection between omega three and the improvement in learning and memory. However, many of these claims are exaggerated to promote a particular type of food or brand with most having such small doses to make little or no difference. There is some evidence published in the medical journal of the American Academy of Neurology that found people who ate more seafood, which naturally contains omega 3, had reduced rates of decline in semantic memory. But there is little evidence to show that supplements work at all. The best advice is to eat fish and nuts as part of a balanced diet but don’t expect your exam results to improve by that much.
  5. Fruit and vegetables – A study conducted by Pennsylvania State University in April 2012 found an association between consuming fruit and vegetables and being in a positive mood.
  6. Water – Despite being the least exciting of them all, water remains one of the best ways in which you can improve brain functionality. Research published in the American Journal of Clinical Nutrition studied 101 participants to see if low water consumption impacted cognition. The result was those who had reduced amounts of water experienced poor memory, reduced energy levels and feelings of anxiety, but those drinking water experienced the opposite.

The evidence on specific foods and its impact on cognition and learning is complex and nuanced. However the connection between the stomach and the brain although still in its early stages has greater potential to lead us to a better understanding as to what we should eat to improve our mental wellbeing.

In the meantime, the best advice is to think about how your diet impacts you personally, identify when you feel best studying is it before a meal or after, pay attention to snacking and of course drink lots of water, eat your greens, all as part of a balanced diet.

Brain overload

Have you ever felt that you just can’t learn anymore, your head is spinning, your brain must be full? And yet we are told that the brains capacity is potentially limitless, made up of around 86 billion neurons.

To understand why both of these may be true, we have to delve a little more into how the brain learns or to be precise how it manages information. In a previous blog I outlined the key parts of the brain and discussed some of the implications for learning – the learning brain, but as you might imagine this is a complex subject, but I should add a fascinating one.

Cognitive load and schemas

Building on the work of George (magic number 7) Miller and Jean Paget’s development of schemas, in 1988 John Sweller introduced us to cognitive load, the idea that we have a limit to the amount of information we can process.

Cognitive load relates to the amount of information that working memory can hold at one time

Human memory can be divided into working memory and long-term memory. Working memory also called short term memory is limited, only capable of holding 7 plus or minus 2 pieces of information at any one time, hence the magic number 7, but long-term memory has arguably infinite capacity.

The limited nature of working memory can be highlighted by asking you to look at the 12 letters below. Take about 5 seconds. Look away from the screen and write down what you can remember on a blank piece of paper.

MBIAWTDHPIBF

Because there are more than 9 characters this will be difficult. 

Schemas – Information is stored in long-term memory in the form of schemas, these are frameworks or concepts that help organise and interpret new information. For example, when you think of a tree it is defined by a number of characteristics, its green, has a trunk and leaves at the end of branches, this is a schema. But when it comes to autumn, the tree is no longer green and loses its leaves, suggesting that this cannot be a tree. However, if you assimilate the new information with your existing schema and accommodate this in a revised version of how you think about a tree, you have effectively learned something new and stored it in long term memory. By holding information in schemas, when new information arrives your brain can very quickly identify if it fits within an existing one and in so doing enable rapid knowledge acquisition and understanding.

The problem therefore lies with working memory and its limited capacity, but if we could change the way we take in information, such that it doesn’t overload working memory the whole process will become more effective.

Avoiding cognitive overload

This is where it gets really interesting from a learning perspective. What can we do to avoid the brain becoming overloaded?

1. Simple first – this may sound like common sense, start with a simple example e.g. 2+2 = 4 and move towards the more complex e.g. 2,423 + 12,324,345. If you start with a complex calculation the brain will struggle to manipulate the numbers or find any pattern.

2. Direct Instruction not discovery – although there is significant merit in figuring things out for yourself, when learning something new it is better to follow guided instruction (teacher led) supported by several examples, starting simple and becoming more complex (as above). When you have created your own schema, you can begin to work independently.

3. Visual overload – a presentation point, avoid having too much information on a page or slide, reveal each part slowly. The secret is to break down complexity into smaller segments. This is the argument for not having too much content all on one page, which is often the case in textbooks. Read with a piece of paper or ruler effectively underlining the words you are reading, moving the paper down revealing a new line at a time.

4. Pictures and words (contiguity) – having “relevant” pictures alongside text helps avoid what’s called split attention. This is why creating your own notes with images as well as text when producing a mind map works so well.

5. Focus, avoid distraction (coherence) – similar to visual overload, remove all unnecessary images and information, keep focused on the task in hand. There may be some nice to know facts, but stick to the essential ones.

6. Key words (redundancy) – when reading or making notes don’t highlight or write down exactly what you read, simplify the sentence, focusing on the key words which will reduce the amount of input.

7. Use existing schemas – if you already have an understanding of a topic or subject, it will be sat within a schema, think how the new information changes your original understanding.

Remember the 12 characters from earlier, if we chunk them into 4 pieces of information and link to an existing schema, you will find it much easier to remember. Here are the same 12 characters chunked down.

FBI – TWA – PHD – IBM

Each one sits within an existing schema e.g. Federal Bureau of Investigation etc, making it easier for the brain to learn the new information.

Note – the above ideas are based on Richard E. Mayer’s principles of multimedia learning.

In conclusion

Understanding more about how the brain works, in particular how to manage some of its limitations as is the case with short term memory not only makes learning more efficient but also gives you confidence that how your learning is the most effective.

The learning brain

Brain 5

There are a number of books that not only taught me something but helped shape the way I think and opened up a whole new world. One such book was Mapping the Mind by Rita Carter, not as you might imagine a book about mind mapping but the Brain. Rita Carter is a science journalist rather than a neuroscientist and understands that it’s not about what she knows but what she can explain.

Having a better understanding of how the brain works will help do far more than improve your grades in a biology exam, you will develop insight as to why something works not only that it does. As a result, you can be confident you are using the most effective brain friendly learning techniques.

The infrastructure Brain 2
Rita Carter provides us with an excellent description of the brain, that it is as big as a coconut, the shape of a walnut, the colour of uncooked liver and consistency of firm jelly.

Imagine a cross section of the brain, taken from the side, alternatively look at the diagram opposite.

The cerebrum or cortex is the largest part of the human brain and is associated with higher brain function such as thought and action. It is divided into four sections.

  • Frontal lobe – associated with reasoning, planning, some speech, movement, emotions, and problem solving
  • Parietal Lobe – associated with movement, orientation, recognition, perception of stimuli
  • Occipital Lobe – associated with visual processing
  • Temporal Lobe – associated with perception and recognition of auditory stimuli, memory, and speech

The cerebellum coordinates movements such as posture, balance, and speech. Next to this is the brain stem, which includes the medulla and pons. These are the older parts of the brain and evolved over 500 million years ago. In fact, if you touch the back of your head and bring your hand forward over the top towards your nose, this effectively maps the ages in which the brain developed.

The Limbic system is largely associated with emotions but contains the hippocampus which is essential for long term memory and learning.

Synaptic gap – Cells that fire together wire together (Hebbian theory)
Although learning is complex, a large amount takes place in the limbic system because this is where the hippocampus sits. Here our memories are catalogued to be filed away in long-term storage across other parts of the cerebral cortex.

What comes next is important because it’s here within the hippocampus where neurons connect across what is called the synaptic gap that learning arguably begins. Synaptic transmission is the process whereby a neuron sends an electrical message, the result of a stimulus across the synaptic gap to another neuron that is waiting to receive it. The neuron’s never touch, the gap is filled by chemicals referred to as neurotransmitters examples of which include dopamine and serotonin. These are often referred to as the body’s chemical messengers.

Learning is making new connections, remembering is keeping them

When the stimulus is repeated the relationship between the neurons becomes stronger and so a memory is formed and learning has taken place. The whole process is called long term potentiation (LTP).

How does this help?
All a bit technical perhaps but very important as it explains so much. It is the reason that repetition is so valuable, for example, if you are reading something and it’s not going in, you need to fire those neurons again but perhaps using different stimulus. Try saying it out loud or drawing a picture alongside the text.

Don’t forget the blog I wrote in January 2018 that explained brain plasticity and how the brain changes as those new neural connections are made, a process called Neurogenesis.

The neurotransmitters, those chemicals released to fill the synaptic gap are also important as each one is different. For example, in addition to making you feel good, it’s likely that when you feel anxious your brain is releasing high levels of serotonin.

Although it’s fair to say there is still much we don’t understand about the brain, I  hope the blog has helped remove some of the mystery of learning, it’s not a magical process but a scientific one.

learn more

Dedicated to my dog Jack – our family dog and best friend

Plastic fantastic – how the brain grows

Stress BallA major new idea was presented to the world in 1991, to many it will mean very little but in terms of improving our understanding of the brain it was a milestone.

Functional magnetic resonance imaging (fMRI) had seen its roots in the earlier MRI, but instead of creating images of organs and tissues, fMRI looks at blood flow in the brain to detect areas of activity and so show how the brain works in real time.

The implications of this for learning are significant because for the first time we were able to identify which parts of the brain were reacting when different tasks were being performed. For example, we know that the cerebrum which is the largest part of the brain performs higher functions such as interpreting touch, vision, hearing, speech, emotions etc.

Brain plasticity

But it is the next discovery that is far more interesting from a learning perspective. For many years the common belief was that brain functionality (intelligence) was to a certain extent hard wired, largely genetic, with a fixed number of neurons. It probably didn’t help that the computer gave us a simile for how the brain worked which was misleading.

That all changed when it became possible to observe the brain and watch how it responded to what it saw and was asked to do. What this showed was that the brain has the ability to generate new cells, a process called Neurogenesis.

Click here to listen to neuroscientist Sandrine Thuret explain how humans can generate new brain cells i.e. Neurogenesis.

This may make sense for children given the basic brain functionality when a child is born, something must be happening to turn them into caring and thoughtful adults. In fact, by adolescence the brain has produced so many synapse, the connections between cells, they have to be cut back or pruned. Hence the term synaptic pruning.  What was perhaps more of a surprise was that growing new brain cells was not just something children could do, adults were able to do it as well.

The classic example is the evidence by Professor Eleanor Maguire from the Wellcome Trust Centre and colleague Dr Katherine Woollett who followed a group of 79 trainee taxi drivers and 31 controls (non-taxi drivers). Their research showed that London taxi drivers developed a greater volume of grey matter i.e.  cell development, three to four years after passing “the knowledge”  when compared to the control group.

Learning about learning

This may leave you thinking, all very interesting but what does it mean for me as a student?

In the same way that people can develop a growth mindset, bringing it within your control, you can do the same with your academic performance. Just because you don’t understand something or pick it up very quickly doesn’t mean that you won’t be able to. This is not to say that some people are not “brighter” than others, it is estimated that around 50%/60% of your intelligence is genetic, but that’s on the assumption your brain cannot change, and what this proves is it can.

And here is one last interesting observation, knowing how the brain works can actually help rewire it. There is evidence that students who know more about how they learn, (meta cognition) will naturally reflect on what they are doing when they are learning which in turn will help grow new cells, how good is that.