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The human brain is the most complex mechanism we know. It has 100 billion neurons, each on average connected (or synapsed) to 10,000 other neurons - a quadrillion synapses, each translating, storing, and processing information.

It has evolved from collective human experience over millions of years, and develops throughout your lifetime based on your own experiences. 

To understand who we are, understand our brains. 
- Are you fixed


What affects your 

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Your brain is where all your ideas, dreams, memories, decisions are made. But most of this is unconscious to you. 

100 billion neurons, each connected on average to 10,000 other neurons. Each neuron is as complicated as a city, containing the entire human genome and millions of proteins. 

This vast, complex biological network is you! Its your dreams and your preferences and your ideas and your agony your ecstasy your imagination your hobbies are all contained in your brain. 
Basis of your decisions and personality and who you are. The entire super system run almost entirely under the hood of conscious awareness. This is intuitively hard to believe - surely everything you do is something you thought about and you decided?

Let's consider what you are doing right now - scrolling through this page with your finger.  You do so with just the right amount of force and you scroll downwards without having to think about it because it is automated. This is a lightning storm of neuro-biological activity (what actually happens? read more here)
How do you get a joke? 

Did you have to learn to feel sad? Did you ever have to learn that you can cry when you are both sad and happy? 
Recognising your friend's face. How did that actually happen?

Hearing your name in a noisy room

Falling in love. Men were asked to rate the attractiveness of women's faces. Half of these women had eyes which were dilated (using eyedrops). Men uniformly rated women with dilated eyes as more attractive. Of course, no one noticed or was even aware that the eyes were dilated. Dilated eyes is a biological sign of sexual readiness in women - your brain responds to this with automated wisdom learnt over millions of years of evolution, which then steers behaviour, without need your conscious inputs. 

What about when you have an idea? What you are aware of is the moment the idea came to your consciousness. But how did that idea come about? It didn't manifest suddenly - your brain has been working on it behind the scenes consolidating and evaluating information, activating associative networks, digging into your memory, and when it is ready, the idea surfaces to your conscious mind. Your consciousness is like the newspaper headline of a country's paper, and your brain is the entire country that is running itself 

These are just some examples of how your unconscious mind plays a big influence in your decisions and behaviour, without you even knowing. 
You are more likely to like someone if you share the same birthday. Dennis or Denise is statistically more likely to become a dentist - implicit egotism. You like things that remind you of yourself. But if you ask Dennises or Deniseses why did you become a dentist, they would have likely formulated a conscious narrative. And they would be convinced by their own narrative even though at least some of them were influenced unconsciously, simply because of their names. 
Statistially more likely to marry someone whose first name begins with the same letter as your first name (in the US). 

Your conscious mind tis the broom closet in the mansion of your brain - David Eagleman

In each of us there is another whom we do not know, Carl Jung
If you hold a mug with hot drink, you will perceive people to be warmer; vice versa for cold drinks. 
phineas Gage - curses, sleeps with prostitutes, gambles. Who you are is intricately tied to your brain. 
Is the mind separate from the brain

Your brain is encased in total darkness and yet paints this beautiful world for you. 
if so much is running under the hood, what can I control? What am I responsible for?
If we didnt study the brain, we would likely never suspect how complex it is and how much is automated, whcih we are unaware of. 

Are you a result of nature or nurture? Are we just born a certain way?

Most of us like to think that we have control over our lives. But what about genetics? Isn't that something out of my control? Aren't I born with a certain set of genes from my parents?


Before we examine this, what is genetics? What is genes? What is DNA? You might have heard that scientists coded a full human genome -what's a genome? 


Each living organism has a unique genome - this is the full string of DNA (you can think of DNA as coming in 4 varieties - A, C, G, T) sequenced in an order several billions long. Genes are particular stretches of DNA that codes of a unique protein

Each living organism has a unique genome - this is the full string of DNA (you can think of DNA coming in 4 varieties: A, C, G, and T) sequenced in a  order (several billions long). Genes are particular stretches of DNA that codes for a unique protein (which then produces a cell, a receptor, a hormone, an enzyme -  all which influences your personality/behaviour/action in some way). 

Here’s the kicker. At least 95% (the estimate is rising...) of your DNA DOES NOT code for genes. We used to think that humans had 100,000 genes (this estimate is dropping....) - it's now closer to 20,000. So what do these non-coding DNA do? Why do we need non-coding DNA if they don't generate genes? Well, non-coding DNA serves as promoters for the coding-DNA, a sort of on-and-off switch that determines when and how coding-DNA expresses the gene.


But what influences the non-coding DNA?

It’s the environment (and think of environment in the broadest possible way, from how your ancestors organised themselves, to life as a fetus, to your experiences after birth).

In other words, genes are not some supreme determinant of who you are. Instead, they are regulated by the bulk of your DNA, which deals with environmental influences. It is also no coincidence that the more complex the organism, the larger the percentage of its DNA that is devoted to gene regulation by the environment. 

A quick but really important example: are males better than females at mathematics ? In the USA where many studies are based, results showed this. In 1983, for every female who scored in the top 10% of math SAT, there were 11 males. If this holds, the difference seems to be largely biological (i.e. genetic). People even came up with possible theories: Males genetically produce 20 times more testosterone than females - maybe it he testosterone fuels the growth of a brain region involved in mathematical thinking (I have no idea who would come up with such a theory but i'm guessing it's a testosterone-filled male)

Of course, it isn't. Like all good science experiments, the experimenters tried to control for all variables except one - gender. All other variables were largely controlled for: the test was the same for everyone, which people took  at the same point of time in life after going through a similar education process. But by doing so, the default finding has to be that any difference can only be explained by that one variable - by genes. 

But what happens if instead it is the interaction between 2 variables that truly account for the difference? What if you take into account differences in the environment? 
A landmark study - Culture, Gender, and Math (Luigi Guison, Paola Sapienza et al)  did so, examining the results of another standardised test - PISA - across 275,000 participants in 60  different countries. You can see the findings in the picture attached (the X-axis graphs for gender inequality, from highest inequality on the left to lowest on the right). Females do generally score lower than males. But this effect is greatly influenced by the environment. In countries where there is greater gender inequality - Turkey, Korea, Italy - females scored significantly worse than males. In countries where there is greater gender equality - Iceland, Sweden, Norway, females scored as well if not better than their male counterparts. (interestingly, females always scored better than males in verbals tests; they scored a little better in countries with great gender inequality, and a lot better in countries with gender equality. Tough day for the boys). 

So what explains the difference in results? As it turns out, cultures with more gender inequality reinforce the stereotype of males being better than females at certain things. Parents are more encouraging and supportive of sons in math (and in education in generally) because "he is probably good at it", while are more lackadaisical with daughters, because they are... female. School teachers are more likely to pick male students to answer questions, and praise male students more for correct answers. 

In "Mindset", Carol Dweck wrote about the examples of Jamie Escalante and Marva Collins, teachers who took over the worst performing group of students, and transformed them to top performers. They did so by not conforming to stereotypes on ability, and by creating a different environment for their students to thrive. She also includes the findings of Benjamin Bloom, an educational researcher who studied 120 top achievers in different fields. Bloom shared that "what any person in the world can learn, almost all persons can learn, if provided with the appropriate prior and current conditions of learning", and that "even by early adolescence, one usually cannot predict future accomplishments from current ability, and it was only the continued motivation and commitment, along with a network of support that made these top achievers." 

Have we really paid attention to the environment that our kids learn, besides that some learn "slower" and some learn "faster"? In Singapore, there is a spiel that we often give, which ostensibly sounds really encouraging and positive: people have different abilities, and our system enables people to rise up and fulfill one’s potential. But there seems to be some hidden implications here, implications that are so natural to us that we might not even notice - there is a belief that potential is fixed, and that different abilities here really refers to that some people just have a lower potential than others. 


It's hard to separate state, emotion, and cognition



We learnt about the importance of neurons in our brains: every brain function (understanding, remembering, communicating, deciding) is performed by a (network of) neuron(s).  A major reason why we are smarter than all other animals is because we have many more times the number of neurons that any other animal has. The more neurons, the more the capacity for learning and knowledge. 

For a long time, it was believed that humans produced neurons only up till abut age 3; thereafter, our neurons slowly die off as we aged.

It took a fierce scientific fight over several decades and the improvement of technology, before we now know for certain. Adult neurogenesis happens - we continue to produce new neurons even into old age. Indeed this happens at a much higher rate than ever expected.  For example, 3% of the neurons in an adult hippocampus are replaced monthly. And if you think about it, this makes perfect sense. The hippocampus is responsible for short-term memory and learning (remember the example of HM?) These
 new neurons are essential and integrative they combine new information with your existing knowledge  - this is where you learn subtleties: the difference between a crocodile and an alligator, between one Kaadashian and another (looks like this neuron hasn't developed for me), between Samoa and American Samoa, between "bank" - the financial institution and "bank" - the sides of a river. 

adult neurogenesis.jpg

So what does adult neurogenesis mean for us? And can we "improve" our rate of neurogenesis?

The answer to both questions relates to learning. The more positive stimulus we provide our brains, the more effective the process of neurogenesis (combined with neuroplasticity).* Reducing stress, a good diet, and exercise seems to also be beneficial. You can hear more from Jim Kwik and Wendy Suzuki.

* There is of course a limit to neurogenesis and neuroplasticity. If it were possible, hile Malcolm Gladwell postulates that 10,000 hours is the magical number to learn something new (I do not think this is true), the converse is definitely not true -  just because you spent 10,000 hours on something doesn't guarantee you become an expert. 

Neuroplasticity - how your brain can be changed to help you become better. 

What's 20 + 11?

You would notice that an answer forms in your head almost instantly. 31, it's easy! But let's take a look at what actually happens in your brain:

  1. The screen you are reading this from reflects light into our eyes.

  2. Your eyes capture the image and send this to the Thalamus. The Thalamus is a waystation in your brain. All signals from your senses go to the Thalamus first, which then decides where to send the signal for further processing.

  3. Your Thalamus notes that this is visual information. So it sends this to your occipital lobe - the part of your brain that deals with sight.

  4. In your occipital lobe, the image is decoded in many, many, many layers. First, the individual pixels are made out. Then the pixels are joined into lines. The lines are combined to form longer lines, until you finally you get the image 20 + 11.

  5. Your brain then recognises at this point that this is mathematics. So its the image: 20 + 11 to the part of your brain that deals with numbers and maths.

  6. The math part of your brain then works out that 20 + 11 = 31. 

  7. Finally, 31, the answer is sent to the control station in your brain - problem solved, answer attained - 31. 

Think about how quickly this happens. By the time you have finished reading the question, your brain has already solved for the answer. You were not aware of the multiple steps required to process the question; you did not need to direct the whole process, the different brain regions were activated automatically.  In fact, it's much better that you were not aware of the processes because you would have slowed it down. Consciousness is merely an afterthought here, and rightfully so. 

But what is it that allows 

Libre Baskerville is a classic font with a modern twist. It's easy to read on screens of every shape and size, and perfect for long blocks of text.


Cognitive dissonance - one of many biases we are affected by

Dartmouth Scar Experiment (Prof Robert Kleck, Darmouth University)

  • Participants were placed into rooms with no mirrors

  • Participants were told that a make-up artist would proceed to draw an ugly scar on their face

  • Once the scar was drawn, participants were given a short glimpse of it

  • Participants were then told to go and interact with strangers, and observe how strangers responded to them

  • Before they left the room, the make-up artist told the participants that they would apply a final coat of powder to prevent the scar from smearing. 

  • What actually happened was that the make-up artist actually removed the scar. 

  • Participants left the room thinking they still wore the make-up of the scar. 

  • Participants overwhelmingly reported that people were more rude and mean to them, and were staring at their sca


Cognitive consequences of forced compliance (Leon Festinger, James Carlsmith)

This is a very famous study that pioneered cognitive dissonance theory. You can read the full paper on their study here. Festinger is the 5th most cited psychologist in the 20th century).

  • Participants were placed into rooms with no mirrors

  • Participants were told that a make-up artist would proceed to draw an ugly scar on their face

  • Once the scar was drawn, participants were given a short glimpse of it

  • Participants were then told to go and interact with strangers, and observe how strangers responded to them

  • Before they left the room, the make-up artist told the participants that they would apply a final coat of powder to prevent the scar from smearing. 

  • What actually happened was that the make-up artist actually removed the scar. 

  • Participants left the room thinking they still wore the make-up of the scar. 

  • Participants overwhelmingly reported that people were more rude and mean to them, and were staring at their sca

  • "if a person is induced to do or say something which is contrary to his private opinion, there will be a tendency for him to change his opinion so as to bring it into correspondence with what he has done or said. The larger the pressure used to elicit the overt behavior… the weaker will be the… tendency

For example, when our 5 senses pick up on something new, this information is sent to the Thalamus which assesses which part off the brain is most suitable to further analyse it. However, if the new information contains something that might be fear-inducing, there is a neural short-cut (known as an amygdala hijack) from the thalamus straight to the amygdala, which then sounds a warning alarm and forces you to react. Imagine you are just lazing on the couch scrolling through your phone. Suddenly, someone throws a snake at you! You jump up and scream in fear. And then you take a closer look... it's actually a rope. Someone played a prank on you. In fact, something similar happened so often in ancient China they came up with an idiom specifically for this: 一朝被蛇咬,十年怕井绳 (translation: once bitten by a snake, we develop a 10 year fear of anything snake-like, even a rope). 


The amygdala also has a direct link with your pre-frontal cortex, the analytical, rational part of your brain. Remember when you watched a horror movie? You know that when the eerie music starts playing someone is going to be haunted by a ghost. Or when we sat on a roller-coaster? You were going to drop very quickly from a very point. We knew what was going to happen. It was not a surprise. We knew that after the activity ended, we will not be harmed. We will be safe and sound and the same as we were before. And yet we were scared out of our minds. Your amygdala was happy to work overtime and suspended your rational thought. Like all emotions, this happens without your control - you don't need to tell yourself to be scared or worried or sad or happy (unless you are pretending!). Otherwise, the emotions happen as a response to what is happening to you, whether you want it or not. 

From the beginning, my research suggested that the amygdala contributes to non-conscious aspects of fear, by which I meant the detection of threats and the control of body responses that help cope with the threat. Conscious fear, I argued in my books The Emotional Brain (Simon and Schuster, 1996) and Synaptic Self (Viking, 2002), and most recently in Anxious (Viking, 2015), is a product of cognitive systems in the neocortex that operate in parallel with the amygdala circuit.  But that subtlety (the distinction between conscious and non-conscious aspects of fear) was lost on most people.  -Joseph Ledox

feeling of “fear” results when the outcome of these various processes (attention, perception, memory, arousal) coalesce in consciousness and compel one to feel “fear.” This can only happen in a brain that has the cognitive wherewithal have the concept of “me,” or what Endel Tulving has called “autonoetic consciousness.”  In a later post, I will elaborate on the autonoetic nature of our conscious feelings. 

An example of the sort of complexity we’re up against here: Both fear conditioning and fear extinction involve activation of inhibitory neurons. Hmm, that commonality seems weird, given opposite outcomes. It turns out that extinction involves activation of neurons that inhibit excitatory neurons, while fear conditioning involves activation of inhibitory neurons that inhibit other inhibitory neurons that project onto excitatory neurons. A double negative, equaling a positive.

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