Posted in History & Literature

Night Vision

During World War II, the British Royal Air Force boasted an impressive accuracy in intercepting Nazi German bombers despite the cover of darkness at night. The British air ministry reported that their fighter pilots ate a large amount of carrots to boost their night vision. Since then, it has become public knowledge that carrots help you see better in the dark.

Unfortunately, this is false. The British air force were not actually using carrots to help see better in the dark; they were using a revolutionary new technology called radar to spot enemy war planes from a far distance. The carrot propaganda was spread to hide this fact from the Germans.

The carrot myth sounds plausible as carrots contain a large amount of beta-carotene, which is converted into vitamin A in the body. Vitamin A is a key chemical required for vision, in the form of retinal. It is true that vitamin A deficiency can cause night blindness. However, the dose of vitamin A required to improve your night vision is so high that it cannot be achieved by simply eating a lot of carrots.

Posted in History & Literature

Evolution Of Colour

We often take the beauty of colour for granted. How would you explain the colour red to a blind person? With that in mind, how do we know that the colour we see with our own eyes is the same hue that others see? A scholar by the name of William Gladstone came across a similar question in 1858 while studying ancient Greek literature. He noticed that in most literature of ancient times, the description of colour was wildly inconsistent, such as the sea being described as “wine-dark”, the sky being “copper-coloured” and other oddities such as violet sheep and green honey. After further analysis, Gladstone found that white and black were referenced frequently, while other colours were much rarer, with red, yellow and green being the most common colours respectively.

Another scholar named Lazarus Geiger expanded on Gladstone’s research and found that throughout ancient literature – including the Bible, Hindu poems, ancient Chinese stories and Norse tales – described beautiful scenes while omitting a certain detail: a blue sky. It appeared that the colour “blue” did not appear in most languages until a certain point in time, despite the people having lived under the same blue sky that we do now.

Geiger tracked the appearance of different colours in different languages and found a pattern of development. Each language would typically describe white (light) and black (dark) first. The next colour to develop was red, then yellow and green, with blue being one of the last colours to appear. This is likely related to the abundance of each colour (e.g. blood, dirt, vegetation) and the ease of making coloured dye (blue dye is notoriously difficult to make).

This raises an interesting question: if the ancient Greeks did not have a word for the colour blue, could they still perceive the colour blue? Biologically speaking, our eyes are not so different to that of the ancient Greeks. But of course vision is a two-part processyour eye captures the image and then your brain processes the image. Does language have a significant enough impact on how we perceive our world?


There is a tribe in Namibia whose language does not distinguish blue and green. A study was held where people from this tribe were shown a circle of 12 squares – 11 green and 1 blue. To the researcher’s intrigue, the men and women of the Himba tribe could not tell which square was the odd one out – suggesting that their brain was processing the two colours as identical. However, the Himba language has more words distinguishing shades of green than English. In another study involving a circle of green squares with one square being a slightly different shade of green, the Himba tribe could pick out the different square much more easily than English-speakers.

The so-called “colour debate” is a hotly debated topic, with some arguing that language plays a crucial role in determining our perception of the world, while others state that language is separate to our senses. What did the ancient Greeks see when they gazed up into the sky? If we cannot describe something with words, then does it truly exist? But one thing is clear – things are not always as they seem.

Posted in Science & Nature

Head Bobbing

If you take the time to look at how most birds walk, such as a chicken or a pigeon, you will notice that they bob their heads. This seems extremely impractical as if we bobbed our heads like that, we would likely become dizzy and vomit quite soon. So why do birds do it and why does it not make them dizzy?

A major difference between birds and human beings is the way our vision works. In humans, our eyes are constantly moving at a rapid rate (saccade) to collate information and stabilise images. Even when we are walking and our head is moving around, our eyes use various sensory information and reflexes to fix our vision at one point, giving us a clear picture. This is such a powerful reflex that one test to check a person’s brainstem function (for example, when they are in a coma) is to move the head and see if the eyes stay fixed on a point or if they follow the head (doll’s eye test). If the brainstem is intact, the eyes will keep looking at a fixed point despite head movement.


Birds on the other hand, cannot fix their vision this way. Instead what they do is they keep their head absolutely still in three-dimensional space when their body is moving. If you hold a chicken in the air and move the body around, you will find that the head stays stationary. This means that when they are walking, the bird’s head will stay still while the body takes a step forwards, then it will move to catch up to the body. From a third person’s point of view, this makes it look like they are bobbing their head, although they are just keeping it very still. In 1978, Dr Barrie J. Frost did an experiment where he put pigeons on a treadmill surrounded by a still backdrop and found that the pigeons did not bob their heads because there was nothing to see.


Posted in Psychology & Medicine

Viscera: Brain

(Learn more about the organs of the human bodies in other posts in the Viscera series here:

(NB: I have written MANY ARK posts about the brain and all the delightful ways it screws up. Some of them are probably the most interesting posts on my blog. Please click the hyperlinks to check out the various related articles! 😀 Alternatively, here’s a convenient list:

Among the many organs of the human body, no organ comes close to the magnificent complexity that is the brain. The brain acts as the command centre of the body. It receives massive amounts of information through the various senses, processes it and sends out electrical signals to control how the body operates. Not only does it control “basic” functions such as movement of muscles, controlling organ functions and regulating homeostasis, it is also responsible for the so-called “higher functions” such as consciousness, emotions and cognition. It is the true seat of the mind and soul.


The brain is the only major visceral organ not located in the trunk (body). It is enclosed in the cranium of the skull, which acts as a protective casing. Because it is a closed box, even a small increase in volume (such as due to a bleed or a tumour) can cause extreme pressures to build, causing severe problems. The entire brain and spinal cord are bathed in a fluid called cerebrospinal fluid (CSF), all enclosed by a sheath made of three layers (dura, arachnoid and pia maters). The brain sends out nerves to the rest of the body, which act as electrical wiring transmitting signals. These include the cranial nerves and the spinal cord, which leaves the bottom of the skull down the spine. The spinal cord branches off into many nerves that supply every nook and cranny of the body. The brain itself is made up of two large hemispheres, which are connected by a bridge called the corpus callosum. Despite popular belief, the actions of the two hemispheres are much more complicated than “analytical vs. creative”. The brain also encompasses the cerebellum (the small stripey structure at the back), which controls coordination and speech articulation, and the brainstem, which is involved in autonomic control of life-sustaining functions such as breathing, and also the source of the cranial nerves.

In the last century, scientists have learned that specific parts of the brain play a specific role. This thought started with the field of phrenology, where small areas of the brain were mapped to a certain mental faculty, such as love, wit or destructiveness. Although this turned out to be complete hokum, the idea stayed and we now know the actual functions of each part of the brain. The brain is broadly divided into four lobes: frontal, parietal, temporal and occipital. The frontal lobe is the domain of thought, personality, motor function and other higher functions. The parietal lobe is related to spatial awareness and sensory functions (such as touch). The temporal lobe is linked to hearing, comprehension of language and storing new memories. The occipital lobe is primarily associated with vision. The brain can then be subdivided into more focussed areas, such as Broca’s area that governs speech and Wernicke’s area that governs listening. It should be noted that the four lobes only describe areas on the surface of the brain (cerebral cortex) where the higher functions belong. The inside of the brain is just as complicated and has many different parts, such as the hypothalamus that is involved in homeostasis, and the hippocampus that converts short-term memories into long-term memories.

How does a lump of cells weighing around 1.5kg produce such wondrous abilities such as philosophical thought, deduction, emotions and calculation? The truth is that we still do not know how the brain functions exactly. However, we know that the brain is composed of a large number of neurons (nerve cells) – about 100 billion of them. These neurons connect to one another via a synapse, which is a gap between two nerve cells where neurotransmitters travel to and fro (allowing electrical impulses to jump from one neuron to another). Using these connections, neurons form an unbelievably intricate and complex network of electrical activity. Because one neuron can connect to many more others, the number of synapses is estimated to be around 100~1000 trillion – significantly more powerful compared to any computer in the world. The number of synapses directly correlates to intelligence and it seems intellectual activities such as reading a book increases the number of synapses in the brain. We have yet to understand exactly how the brain uses this incredible computational power to produce cognition and self-awareness.


(Video of neuronal activities in a zebrafish brain)

Because the brain uses electrical impulses for most of its functions, a common abnormality that is seen with the brain is when the electrical activity becomes disorganised and out of control – a seizure. This abnormal electrical activity may be due to a focal problem such as a tumour, or a generalised misfiring of neurons or altered regulation of electrical activity. When a seizure happens, the disorganised activity results in the brain not being able to function normally. For example, the most common consequence is a fit (tonic-clonic seizure) where every muscle spasms out of control, because the muscles are overloaded with chaotic signals. Focal seizures can cause fascinating symptoms depending on the location, such as temporal lobe seizures causing religious visions (hallucination). This also disrupts consciousness, which is why most epilepsy patients do not remember the event.

Posted in Psychology & Medicine


They say that human imagination is infinite and limitless. But consider this: can you imagine a colour outside of the visible spectrum? Most likely, you are incapable of thinking of a new colour that cannot be mapped on a standard colour chart. Interestingly, a small proportion of people can see and understand colours beyond the range that the majority of us can see.

The physiology of vision is rather complex, but essentially boils down to the retina (inside lining of the eyeball) acting as a film for the image that you see. Cells known as photoreceptors convert the visual image into electrical signals that are transmitted to the occipital lobe of the brain via the optic nerve. There are two types of photoreceptors: rod cells, which sense movement, and cone cells, which sense colour and provide sharp images (visual acuity). Human beings typically see colour by combining three primary colours: red, green and blue (known as the RGB system). There are cone cells for each primary colour. The brain processes the signals sent by each cone cells and figures out what “colour” you are seeing. Therefore, you can only perceive colours made from a combination of red, green and blue. It is easy to visualise this by playing with colour palettes on computer programs such as Photoshop.

In recent years, it has been speculated that a certain percentage of women have an extra type of cone cell that senses a different wavelength of light. Ergo, they can theoretically sense a greater range of colours compared to someone who has three types of cone cells. This condition is called tetrachromacy (“four colours”). Tetrachromacy is the opposite to colour blindness, which is caused by a deficiency or fault in one or two types of cone cells. To these people, the average person (a trichromat) will appear “colour blind”.

According to one estimate, as many as 12% of women are tetrachromats. Although there are many theoretical barriers to true tetrachromacy, there have been several documented cases of women who perceive colour in much more depth.

The ability to see an extra primary colour is more significant than just a 25% increase in the person’s colour range. An average person can see about 1 million different hues (shades of colours), while a true tetrachromat can see 100 million hues – a hundred-fold increase in the range of colours they can see. One can only wonder what kind of amazing sights a tetrachromat sees when she gazes upon a field of flowers or even a rainbow. Unfortunately, even if a tetrachromat tried to explain the colours she saw to us, we would not be able to grasp the colours as our minds would be incapable of visualising the colours, much like how describing the colour red to a blind person is impossible.

Posted in Science & Nature


Consider this: if you see something that is not there, or not see something correctly, is that due to a problem in your eyes or your brain? An interesting anatomical fact is that the eyes are part of the brain. They originally evolved from the brain and drifted further and further forwards, connected to the brain by the optic nerves. If you lift a brain out from the skull, the eyes would be pulled backwards too. But technically speaking, eyes are distinct organs by themselves that have merely originated from a portion of the brain. It does not think or make decisions by itself. Just like a camera, an eye records things as it sees it and transmits it to the brain via the optic nerve via electrical signals. The brain then processes the signals in the occipital lobe, located at the back of the head (this is why you “see stars” when you bang the back of your head).

This means that vision can be altered anywhere along the pathway. If you have cataracts, where the lens of the eye becomes clouded, you lose portions of your visual field. If you have a large pituitary gland tumour, it presses on the optic nerve and causes double vision (diplopia) or vision loss. If you have a stroke in the occipital lobe, you can lose your vision. The brain’s role in producing vision can easily be demonstrated in the form of optical illusions. The eye merely records and transmits what it sees, but the brain becomes confused by what information it receives and tries to make sense of it. In the process, we experience bizarre illusions such as static images moving by themselves.

Because of this intricate pathway, some pathologies present with fascinating symptoms. A condition called Anton’s blindness (or Anton-Babinski syndrome) causes a patient to “see” despite being blind. Patients with Anton’s blindness are adamant that they can see perfectly clearly, and will even describe what they are seeing. However, what they “see” is completely different to what the object actually looks like. For example, if the patient looked at a blonde woman wearing a yellow blouse and a red skirt, they may describe her as a brunette woman wearing a blue shirt and black jeans.

The reason for their blindness is that their occipital lobe was damaged (usually by a stroke), leading to an inability to process the information from the eyes. Although the eyes are pristine and record what they see in perfect detail, the brain is incapable of interpreting the signals. The brain then goes on to confabulate, where the brain fills the gap by conjuring up false information. This makes Anton’s blindness quite hard to pick up on as the patient will not complain of it. It is only found when someone pays close attention to the patient and notices subtle cues like the patient bumping into furniture or talking in the direction where they think a person is at (even after they move). Ergo, the patient adamantly believes that they can see as their brain thinks it is seeing things (even though it is not receiving the information from the eyes properly).

Seeing is not believing. You see what you believe.

Posted in Psychology & Medicine


Every person has had the experience of having a few seconds of brilliance just before their consciousness slips into sleep. During this short moment, we have some of the most creative and innovative ideas. Unfortunately, this is all lost by the time we wake up. This state is known as the hypnagogic state and has been well known since ancient Greece. Many philosophers and writers such as Aristotle and Edgar Allan Poe have written on the subject and how they received some of their greatest ideas in this state. 

Recent researches show that during hypnagogia, thought processes and cognition vastly differs to normal wakefulness. It appears that hypnagogic cognition is more based on the subconscious mind, with people in this state being more open to suggestion (e.g. hypnosis). Ideas seem to flow in a fluid yet illogical way and they are based on external stimuli, thus explaining the heightened suggestibility as the brain incorporates the surrounding into its thought process. The thought process is also less restricted, leading to openness and sensitivity. A process called autosymbolism occurs where abstract ideas that we are thinking are converted into concrete images. This explains the artistic inspiration seen in hypnagogia.

One of the more pronounced phenomena of hypnagogia is insight. It has been noted by many people throughout history that the moment before sleep is when we have the best ideas. For example, a chemist called August Kekulé realised that benzene was a ring structure after seeing an image of snakes biting each other’s tails to form a ring. Because of this, many famous artists and inventors tried to harness the power of hypnagogia through techniques such as the Dalí nap. Thomas Edison, Isaac Newton, Beethoven and Richard Wagner also practised similar techniques to gain insight into a problem that they were trying to solve or bring fresh ideas.

Another fascinating side of hypnagogia is the strange sensory phenomena associated with it. As in the case of sleep paralysis (which usually occurs in hypnapomp – the state between sleep and waking up), people often report strong hallucinations in the form of bright colours, geometric shapes, or even nightmarish visions (such as a ghost sitting on your chest). Other senses are affected as well, such as hearing whispering (commonly associated with the nightmarish hallucinations mentioned above) or out-of-body experiences. Hypnic jerks are also common, where the person jerks awake just before drifting off to sleep. This is thought to be caused by the brain misinterpreting sleep as “death” or the body shutting down, leading it to jolt the system back to life. 

Finally, an interesting psychological phenomenon is the Tetris effect, where people who have spent a prolonged time on one activity cannot stop seeing images and thinking about that activity in the hypnagogic state. This was seen in people who had played too much Tetris seeing coloured bricks before they went to sleep. Other common versions of the Tetris effect include chess boards and pieces, feeling waves after being at sea and seeing words and numbers after working on documents for a long time.

The combination of insight, creativity and sensory illusions leads to hypnagogia causing strange “experiences”. Ergo, hypnagogia is now thought to explain many supernatural experiences such as ghost sightings, UFO abductions, premonitions and visions.

Posted in Psychology & Medicine

Beer Goggles

There’s only one thing other than love that can make a person oversee another’s weaknesses and amplify their strengths – alcohol. The term beer goggles refers to this phenomenon, where a member of the opposite sex appears more attractive due to the influence of alcohol. This is because alcohol inhibits the cerebral cortex where higher order thinking occurs, reducing sexual inhibition and allowing primitive behaviour to surface.
Beer goggles can be utilised to increase the chances of succeeding in courtship if one knows how to manipulate it.

There is even an equation to calculate the strength of beer goggles, produced from actual scientific research and experiments. The equation is:

An = number of units of alcohol consumed
S = smokiness of the room (graded from 0-10, where 0 clear air; 10 extremely smoky)
L = luminance of ‘person of interest’ (candelas per square metre; typically 1 pitch black; 150 as seen in normal room lighting)
Vo = Snellen visual acuity (6/6 normal; 6/12 just meets driving standard)
d = distance from ‘person of interest’ (metres; 0.5 to 3 metres)

Ergo, the more you drink, the further you are from them, the smokier and darker it is and the worse your eyesight, the beer goggle index (ß) rises and the subject becomes more attractive, thus increasing the probability that you will approach that person.

Posted in Psychology & Medicine

Alice In Wonderland Syndrome

There is a disease called Alice in Wonderland Syndrome. This causes patients to suffer massive migraines, while suffering visual hallucinations that alter their perception of what they see.
For example, they see objects as bigger or smaller than what they actually are, or even see them as upside-down. Because of this, people who have experienced this syndrome say that it was like living in a fairy tale. There is no known cure, but it is often temporary and will one day disappear like magic.

When you fall in love, the other person’s weaknesses seem smaller, their strengths seem bigger, and sometimes they turn your world upside-down. So is love like living in a fairy tale, or like suffering a disease?.