Tag: eyes

Posted in Psychology & Medicine

Watching You

Posted on by Jinavie

What drives our morality? Philosophers have argued and pondered for millennia where our sense of selflessness, altruism and honesty come from. Are we inherently good or evil? Do we only help others when it benefits us? How can we motivate people to act more morally?

One interesting research reveals a startling truth about our morality.

In 2006, psychologist Melissa Bateson published a research where she experimented with eyes. Their university tea room had an honour-based coffee and tea system, where you pay the price of the beverage into a box. Because there was no one keeping guard over the box, you could choose to cheat the system by taking a free drink without paying. Bateson wanted to see if she could influence how often people paid by making a simple alteration to the notice banner.

The notice banner had the prices for tea, coffee and milk. Bateson decided to add an image above the prices: a pair of eyes, or flowers. She would alternate the image used week by week, then recorded the total earnings and the number of drinks purchased. She would use different flowers and different eyes from various genders, ethnicities and expressions, but the eyes all had something in common: they stared directly at you.

The results were fascinating: on weeks where the notice banner included pictures of eyes, people paid 2.76 times as much compared to the flower weeks.

Turns out, seeing a depiction of eyes makes us more honest and cheat less. The same effect has been seen when using cartoons or drawings of eyes, resulting in less littering, more donations, less crime and overall more pro-social behaviours. This is called the watching-eye effect.

Why do harmless pictures of eyes make us want to do good?

The effect is likely to be an unconscious, automatic reaction. Our brains are remarkably sensitive to eyes and gaze – which is why we can easily spot people staring at us and why we are so good at reading emotions from eyes.

Furthermore, we are social animals and thus have evolved to show pro-social behaviours so that we fit into the group and live together harmoniously.

This means that when we see even a symbol of an eye, our brain automatically thinks that we are being watched by someone, pushing us to act morally to avoid punishment or embarrassment. This suggests that our desire to preserve our social reputation plays a significant role in our morality (but by no means the only factor).

The other thing to consider is that as we grow up, we are continuously taught that we are being watched, to dissuade us from bad behaviour. God will send you to hell, Santa Claus will put you on the naughty list and Big Brother will send you to prison. All of these stories and cultural beliefs fuel our subconscious paranoia of being watched and fear of consequences.

So if your lunch keeps getting stolen from the fridge, try sending a message by putting a photo of eyes on it to see if it deters your coworkers.

Posted in Psychology & Medicine

Dark Circles

Posted on by Jinavie

One of the most tell-tale signs that someone is extremely tired or sleep deprived is having dark circles around the eyes. The skin beneath the eyelids are very thin – almost a quarter of the thickness of skin elsewhere on the body.

During times of exhaustion, the skin becomes paler due to a number of factors. The paleness makes it easier to see the blood vessels running under the skin, which shows as a greyish-blue tint. The more vessels that can be seen and the paler the skin, the darker the circle appears.

Dark circles appear to be an inherited trait, most likely related to the thickness and transparency of your skin. It is also more common in people with hay fever, anaemia and liver problems. The only real treatment for dark circles is rest.

Posted in Science & Nature

Head Bobbing

Posted on by Jinavie

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.

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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.

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Posted in Psychology & Medicine

Eye Contact

Posted on by Jinavie

When you see a person of the opposite sex for the first time, what part do you see first? Each person may give a different body part such as face, shoulders, legs or breasts, but the universal truth is that most people will unconsciously look at the person’s eyes first. The eyes are literally “windows to the soul”, providing valuable information about the person’s state of mood and mind.

Eye contact is an important part of social life. Looking directly into someone’s eyes conveys the message of “I am interested in what you are saying and you have my attention”, as if a bridge is made between the two people’s minds. Strong eye contact is a common feature of two people in love, as they communicate non-verbally to share their feelings of attraction. Good eye contact is seen as “socially appropriate”, giving the person an air of confidence and helping them build better rapport with the person they are talking to as the other person feels listened to and that they matter.

However, eye contact may not always be a good thing. If eye contact is too intense, the other person will become uncomfortable as they may feel that they are being probed and their privacy is being invaded. This is why people in crowds, such as in the subway, avoid eye contact with each other as to protect their privacy.

In Eastern cultures, direct eye contact may be seen as disrespectful, especially when speaking to a superior or a person older than you. To show respect, the person lower in hierarchy lowers their gaze.

Certain psychiatric disorders can result in poor eye contact. It is common for patients with depression or social anxiety to avert eye contact, minimising the social connection that comes from it. Autistic children are particularly famous for finding it extremely difficult to make eye contact with others as it unsettles them. The poor eye contact gives these people a cold, uncaring, weak image which may be criticised by other people.

Unlike modern humans, many animals perceive eye contact as a threat or a sign of aggression. It is very dangerous to maintain eye contact with an aggressive monkey or dog as it will increase your chance of being attacked.

Posted in Psychology & Medicine

Tetrachromacy

Posted on by Jinavie

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.

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Posted in Science & Nature

Vision

Posted on by Jinavie

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, Special Long Essays

Lie Detection

Posted on by Jinavie

In developmental psychology, a child’s ability to successfully lie is considered a milestone achievement. This goes to show how lying is one of the characteristic behaviours of human beings. Even a three-year old knows that by lying, they can avoid punishment and gain much more.

There are many signs of deception. Becoming an expert in observing these signs and knowing what they mean can grant the ability to see through lies. The following is a description of some of the changes – both non-verbal and verbal – that people exhibit when lying. Note that these signs are not always definitive and should be used as a reference only. One must carefully deduce whether the signs are there because the person is lying, or whether it is a simple physiological process with no meaning. Here is a simplified list of the signs that will be discussed:

  • faster blinking, avoiding/too much eye contact, dilated pupils, looking up and right
  • sweaty face and palms, fast pulse and blood pressure, flushed face
  • dry mouth/lips, constant licking or pursing lips, swallowing loudly and often
  • looking away or down, tics and twitches in face (eyes, cheeks, mouth)
  • placing hand near mouth (rubbing nose/chin, scratching face etc.)
  • touching neck, pulling at collar, rubbing forearms or hands
  • shoulder shrug, crossed arms/legs, fidgeting, hiding of hands
  • holding hands or clenched fists, unusual movements
  • tucking feet below seat, tapping of feet
  • short, general descriptions (or overly detailed), inconsistencies in detail
  • talking faster and at a higher pitch, emphasising the “truth”

Non-verbal signs are essentially body language – a mean of subconscious communication through which the person signals to another person about their emotions and thoughts. These can be behavioural (avoiding eye contact), physiological (faster heart rate) or cognitive (exaggerating that they are “truthful”). As non-verbal communication makes up 90% of a conversation, it is extremely useful to know what signs to look for and know what they mean. Let us start with the face.

The eyes are considered the window to the soul. This is because the eyes give off so many clues about what the person is thinking, usually subconsciously. A key sign to look for is the frequency of blinking. If the person is blinking much more than usual, it suggests that they are nervous (causing their eyes to dry out faster). Another famous example is eye contact – people avoid eye contact when lying as they are subconsciously “ashamed” of being immoral. However, they may consciously compensate this and make too much eye contact, another sign they are hiding something. Looking up and to the right has been associated with the brain imagining something, as opposed to down and left which is related to recalling true memories. Lastly, the pupils may dilate from the excitement and nervousness.

When a person lies, they tend to be nervous, stressed and excited. This activates the sympathetic nervous system, colloquially known as the fight or flight mode (rapid blinking is related to this). This causes other signs such as sweating, dry mouth, fast heartbeat and blood pressure. Therefore, a liar may be seen licking or pursing their lips to moisten them. Frequent, loud swallowing is also a clear sign of dry mouth. The face may be slightly flushed as well.

As stated above, the person is also subconsciously ashamed of their lying. This causes the person to face away from the person or look down (think of a child who is lying – their innocence makes signs of deception flare up like Christmas lights). Many people place their hand near their mouth (e.g. rubbing their nose or chin, touching their lips), as if the brain is telling the hands to stop the lie from coming out. They also tend to rub their neck or adjust their collar as touching the neck comforts people. Note that scratching the nose is another sign of lying but not the same as rubbing the nose. Scratching is to relieve the itchiness caused by the raised blood pressure irritating the soft tissue of the nose (Pinocchio effect).

Obviously the facial expression would change also, expressing nervousness and mild stress. This may be concealed with a fake smile (when the “eyes don’t smile”) or anger. It is well-known that people exhibit microexpressions – a flicker of emotion expressed in the face – that only shows for a fraction of a second. Although it is hard to spot, it is a direct display of their true emotion. Fascinatingly, the right face tends to react more as it is controlled by the left brain – responsible for the logical and complex thinking required in telling a lie. This may show as a tic or twitch in the eyes, cheek or mouth.

Moving down the body, a classic sign of deception is the shoulder shrug. Shrugging the shoulders is a message they are “unsure” if what they said is true and is seen (subtly) in many cases of lies. The arms may be crossed (a closed position), which shows they are being defensive (a sign of guilt or discomfort). Similarly, the person may be leaning away from the other person.

The hands are just as important as the face when it comes to lie detection. As mentioned before liars tend to touch various parts of their face and neck while telling a lie. Women tend to rub their hands together or their forearm instead of the neck to comfort themselves. Fidgeting is also very important to notice as this is a comforting act too and exaggerating movements are seen also (reinforcing the “validity” of their lie). Usually, people are aware of this fact and attempt to hide their hands in their pockets, behind their back or behind a bag. They may hold the hands together to prevent fidgeting, or tightly clench their fists. Basically, look for unnecessary (or lack thereof) movements as this almost certainly indicates that something is abnormal.
Similarly, the person may cross their legs (defensive), tuck their feet below the seat (distancing from the other person) or tap their feet (nervousness and excitement).

To finish off, here are some verbal cues for deception. People have a tendency to give short replies when lying. They also talk at a faster pace and higher pitch. These are all due to the subconscious want for the conversation to be over as soon as possible (often accompanied by an awkward or angry attempt at changing the topic). On a similar note, they are more hesitant and less fluent in talking, adding many “umm”s and “uhh”s as they try conjure a lie. Words such as “somebody” “somewhere” “everywhere” that encompass a non-specific or broad target are used to try dilute the details of the lie.

Conversely, the more experienced liar tries to make their lie believable by adding excessive detail to their story. For example, asking a specific detail (that they normally wouldn’t notice) would prompt an answer as opposed to an “I don’t remember”. It is also useful to ask the same question again and check for any inconsistencies.
Lastly, if the more the person affirms that they are telling the truth (e.g. “honestly”, “believe me”, “swear to god”), the more likely they are lying.

This list is not exhaustive and there are many tiny details that can be used to help you decide whether someone is trying to deceive you or not. Again, as the signs are not definitive (e.g. they may be thirsty or just nervous talking to you) it should be considered within the context along with other information. However, it is still an extremely useful tool for finding the truth as everybody lies.

Posted in Psychology & Medicine

Locked-in Syndrome

Posted on by Jinavie

Imagine that one day, you wake up, but then no matter how hard you try, you cannot move a single part of your body. Trying to roll out of bed, lifting your arm, or even moving your fingers is impossible. You think it is merely sleep paralysis, but you soon realise that it is not as simple as that, or even a dream. No voice escapes your throat.
The only thing you can do is blink and roll your eyes around.

Welcome to the world of Locked-in Syndrome (LIS), a neurological condition where your brain has no connection to all the muscles in your body. The actual symptoms list is: quadriplegia, paralysis of most facial muscles, inability to speak, with complete preservation of cognitive function (sometimes sensation too). In simpler terms, a LIS patient’s mind is essentially trapped inside an unmoving body, with only the senses and eyes to interact with the real world.

It is caused by damage to a part of the brainstem known as the pons, which not only carries motor nerve fibres to the spinal cord (where it then carries on to supply the muscles of the body), but is also the origin of some cranial nerves. This explains the symptoms of paralysis, even the face (e.g. damage to the facial nerve, or CN VII). More specifically, the damage only affects the pons and not the brain itself, meaning that cognition (thinking), intelligence, memory and sensation (if the fibres are spared in the brainstem) are completely functional.
This can be caused by trauma, stroke, drugs, degenerative neuropathies, or anything that can selectively damage the pons.

Due to the nature of the disease, there are no treatment or cures for LIS. Prognosis is very poor and most patients are not expected to regain motor control. This can be very distressing news to LIS patients, as it essentially means that they will be trapped in a motionless, voiceless body for the rest of their natural lives, which could feel like eternity. Although over 90% of the patients die within 4 months, some continue to survive for much longer periods. To improve their quality of life, methods have been developed to allow the patients to communicate, such as Morse code (by blinking eyes) or alphabet boards. Technology is allowing even better options such as eye-tracking and brain-computer interfaces, where a machine tries to interpret a pattern in brain activity, trying to relate a certain action to a pattern. This may allow simple communication such as yes/no answers.

Because of the almost complete paralysis, even professional neurologists often miss this condition, diagnosing the patient as being in a vegetative state.
What would it be like to be trapped in your own body – or “living corpse” as described by Alexandre Dumas in The Count of Monte Cristo – and not be able to tell others that you were still in there?