Super-senses in the Animal Kingdom

Sophia Akiva

Some hold the belief that humans were made in the image of an omnipotent being, while others consider us to have adapted through evolution to become the dominant species on our planet. The debate between these views is best left for another time, but for a species that has no natural predators, can survive on all seven continents and has built technologically advanced civilisations, our sense of superiority over our four-legged cousins is well justified. Yet still we yearn for more, imagining superheroes with inhuman abilities and senses, taking inspiration from the very creatures we consider to be less than us. Our brains may be better developed when it comes to reason and logic, and that in itself can be considered a superpower, but the animal kingdom is filled with creatures that have brilliant powers of their own.

First of all, let us consider eyesight. Human vision is very advanced and adapted perfectly to the peak wavelength of sunlight we receive through the atmosphere, however as soon as the Sun sets we are left at a disadvantage. Animals like tarsiers on the other hand, are not. These tiny adorable creatures are also deadly predators, being the only primates to be fully carnivorous, and responsible for this are their super-sensitive eyes.

Unlike other nocturnal creatures, tarsiers do not have a reflective layer behind their retinas and so are unable to bounce faint light through them twice in order to absorb it. To compensate for this, their eyes have grown to colossal proportions relative to their small body size, with each eye being approximately the same size as the brain, which itself has grown large in areas responsible for processing all the visual information thus received. As well as turning these little mammals into perfect hunters, their incredible sight is also used to traverse the canopies in the night and to defend against predators, who are often attacked by one or more groups of tarsiers upon being detected.

The animal most famous for having incredibly powerful eyesight is the eagle. Not only can they see much further than a human but the images their brain interprets are of higher resolution due to a greater number of light-sensing cone cells within the retina. The range of light frequencies they can detect extend beyond visible light and into the ultraviolet, an ability that is also shared by a completely different creature, the mantis shrimp. This crustacean can show off an even more impressive eyesight than its feathered peer, with up to 16 visual pigments compared to five in the eagle and our own measly three.

Image Credit: Wikipedia

Like the two animals mentioned above, the mantis shrimp also uses its superhuman power to hunt down prey but is different in having the additional ability to identify the polarisation of light it detects through eye movements and distribution of cones. But it doesn’t end there, with their survival resting solely on their vision, these creatures have developed a way to insure it. This comes in the form of binocular vision, which is necessary for many predators, present independently in each eye of the mantis shrimp! So if they ever lose an eye, their depth perception would remain uninhibited. With so many processes going on within the eyes at the same time, the information has to be analysed by the eye itself before being transferred to the brain.

Let us now move onto the super sense of touch, which brings with it an introduction to another majestic predator of the animal kingdom, the star-nosed mole. This mammal is often rudely listed as one of the ugliest animals on Earth due to the tentacles extending from its snout, which are densely packed with sensory receptors and allow it to feel the movement of its prey. This specially adapted snout serves a second purpose of keeping soil from entering the mole’s airways as it burrows through its network of underground tunnels. This habitat has driven the development of such superb sensitivity in one sense, yet has caused the mole to lose almost complete use of another, leaving these animals practically blind.

Another animal  that appears to have sacrificed one sense to become the master of another is the snake, however their deafness in a long standing misconception. Although they do not possess sound detectors outside of their body, they are still able to process auditory information from the vibrations they pick up from the ground. This is the same mechanism they use to process their own super sense of touch. Snakes are able to differentiate the vibrations passing into their skeleton from the ground as either sound or mechanical and so the signals are passed through different sensory organs and processed by different parts of the brain. But the magnificence of the serpent doesn’t end there, their sense of taste is also superhuman. The famous forked tongue of the snake not only allows the animal to detect its prey, but also to determine the direction from which it is coming.

The animals discussed here are just a few examples of the vast variety of fascinating creatures that possess incredible sensory abilities, many of which are still currently being researched. We humans are not without our own merits. We may not be able to spot a rabbit from two miles away but we are the only species on Earth to have gazed upon the surface of Pluto – so perhaps our intelligence really is a superpower after all.

Sleep Paralysis: Frozen to the Spot

Emma Brudanell

You wake in the dead of night and look around the familiar setting of your bedroom. Everything initially looks normal, but something feels slightly different. You sense that you are not alone.  Then out of the corner of your eye, you see an eerie shadow. You try to move, try to sit up and get a better view, but you can’t – you’re completely paralysed.

While this may sound like something out of a horror story, what I have just described is a personal description of the phenomenon known as sleep paralysis, experienced in some form or another by up to 8% of the population.

What is sleep paralysis?

Sleep paralysis is a condition defined by the temporary inability to move or talk whilst falling asleep or waking up. It can often be accompanied by terrifying and bizarre visual or auditory hallucinations and usually passes in a few seconds or minutes.

Sufferers describe some or all of the following symptoms:

• Difficulty taking deep breaths
• Inability to move or speak
• Sensed presence
• Hallucinations
• Intense fear

Sleep paralysis has been long been associated with evil spirits, demons and supernatural entities. Symptoms have been described by many different cultures and throughout history and it may be the superstitions entwined in cultures which act as a catalyst for the hallucinations experienced.  For example, many African cultures attribute voodoo magic as it’s cause, with the attacks being due to zombies coming to visit in the night. Whilst in the Caribbean sleep paralysis, also known as ‘kokma’, is believed to be caused by the souls of dead unbaptized babies who come and strangle victims in their sleep.

Image Credit: Pixabay

Causes of sleep paralysis

Sleep paralysis is a recognised condition caused by the body not moving through the stages of sleep properly. There are two types of sleep paralysis; one occurs when your falling asleep, called predormital sleep paralysis and the other when you’re waking up, called postdormital sleep paralysis.

Predormital sleep paralysis occurs when your body relaxes as you start to enter into a sleep cycle but your mind still remains conscious and is aware that you can’t move or speak. It is often associated with the sleep condition narcolepsy, which results from the brain’s inability to regulate normal sleep wake cycles.

Postdormital sleep paralysis is much more common and occurs when your body wakes from a state of REM (rapid eye movement) sleep. During REM sleep, the most vivid dreams occur and your body is paralysed by your brain to prevent you from acting these dreams out. Sleep paralysis can occur when your brain awakes from and incomplete cycle of REM sleep, whilst your body is still paralysed.

Risk factors

Whilst there is no known definitive cause of sleep paralysis, it has been linked to: stress, certain medications, depression, substance abuse and recently a gene which helps regulates our bodies’ sense of time. It has been associated with other sleep conditions and has also found to be more common in psychiatric patients, being experienced by up to 32% of them (and, interestingly, 28% of students).

Prevention and treatment

Luckily, although terrifying sleep paralysis isn’t actually dangerous and most of the time there is no need for any treatment, although in particular cases low doses of anti-depressants may be prescribed. Some tips for avoiding it include; sleeping on your side, establishing a regular sleep cycle, regular exercise and avoiding eating, drinking or smoking just before bed.
Sleep tight.

The Science Behind the Perfect Nap

Katie Jones

Leonardo DaVinci, Albert Einstein and Winston Churchill are amongst some of the most influential people in human history. Despite being run off their feet painting beautiful masterpieces, developing the general theory of relativity, and leading Britain through World War Two; they all still found time for a well-earned nap. But, what is the key to a successful nap? Why is it that sometimes they make us feel groggy and other times they put a spring in our step?

Recent evidence suggests that there are three main types of sleeping. Planned napping, this is where a nap is used to prevent tiredness that might occur later in the day. For example, if you know you won’t get to bed till later than usual, you may want to have a nap earlier in the day to keep yourself going. In contrast, when you suddenly become hit by a wave of tiredness, an emergency nap may sort you right out. This type of nap can combat drowsiness and means you can carry on the activity you were originally engaged in with a new lease of life. And finally, there’s habitual napping, often seen in young children who may fall asleep at the same time every day.

Image Credit: Flickr

Napping for different lengths of time have varying effects on our brain, and can alter the effectiveness of the nap on relieving tiredness. Recent evidence suggests that naps of different duration provide us with different benefits.

The common Power Nap (15-20 minutes) is suggested to provide a quick jolt of alertness and decrease fatigue – and is often claimed to be the most beneficial length of nap. A nap of between 40-60 minutes is thought to help in memory by forcing memories into the long term memory store of the brain whilst we sleep. However, a sleep for this length of time can lead to grogginess for around half an hour after the nap. This grogginess is technically referred to as sleep inertia, and can be dangerous if alertness is required immediately after waking from the nap. A longer nap of around 90 minutes is referred to as an REM (rapid eye movement) nap. A nap this long avoids the sleep inertia that is experienced with other, shorter types of nap, and is also claimed to improve creativity and memory.

Achieving the best nap possible, requires a room that is as dark and quiet as possible; lying in a comfortable position, and not putting undue strain on your back or neck. The time of the nap is also important, too late and it may disrupt your nightly sleeping pattern. Experts suggest that an ideal napping time is around 4pm.

Often, napping is associated with laziness and a weak work ethic, however a lot of companies now see the benefits of napping to their employees and are beginning to offer “energy pods” or “quiet rooms” that can be used as a napping spot.

Now armed with your new found napping knowledge, plan yourself the ultimate nap and wake up rejuvenated and ready to face the day (or whatever’s left of it).

 

Uncertain-tea?

James Vines

In Britain, 165 million cups of tea are consumed every single day, with English Breakfast tea being the most common. The matter of a perfect cup of tea is a highly contentious topic. There are so many variables. Do you add sugar? What’s the perfect amount of milk? And maybe the most contentious of them all, how long do you brew for?

98% of us take our tea with milk, but one of the first to scientifically investigate the effects of adding milk to tea was statistician Ronald A. Fisher in 1935, who was interested in the effects of adding milk before or after the water. His study was only conducted upon one participant, Muriel Bristol, who claimed she could taste the difference. While the finer intricacies of Fishers experiments were really concerned with statistical probabilities, he also concluded that Bristol could, most probably, tell the difference between the two different types of tea.

Image Credit: Flickr

There are many arguments both for and against pouring the milk in first. Tradition dictates that milk is added first. One theory for this concerns the delicate nature of early teacups, which were prone to cracking under a sudden influx of recently-boiled water. Another theory suggests that milk which is creamy or warm may rise to the surface of a cup of tea as globules of fat. This was also thought to kill bacteria by boiling them, which may be lurking in questionable milk.

While these arguments all seem reasonable, in 1946, George Orwell argued “by putting the tea in first and then stirring as one pours, one can exactly regulate the amount of milk, whereas one is liable to put in too much milk the other way round”. In 2008, the Royal Society of Chemistry also got involved suggesting that adding milk second could ‘cook’ the milk, giving it a boiled taste due to greater denaturing of the proteins. Whether this ‘boiled’ taste is preferable however, was not mentioned. Of course it is important to mention, that the above only concerns tea poured from a pot; milk must be added second if brewing in the cup, or else the tea bag will not reach a hot enough temperature to infuse properly.

Another hot topic in the tea drinking debate is whether to add sugar. 41% of tea drinkers take sugar; as a result the issue of sugar is somewhat down to personal preference. For certain however, sugar should be added in the cup, and only once the tea bag has been removed. This prevents any sugar getting caught up and wasted inside the tea bag.

A less contentious area is the question of loose tea versus tea bags;  most tea lovers will agree that loose tea leaves make for a better brew. The tea in teabags is normally made from the “dust and fannings” from broken tea leaves, rather than the leaves themselves. This affects the quality of the tea. Finely broken leaves loose their oils and aroma, resulting in a more bitter taste. While tea bags are somewhat inferior, their cost and convenience make them more desirable for millions of us, with loose tea making up just 1% of all tea purchases.

It is almost without question among tea connoisseurs, tea should be made in the pot, not in the cup, but how long should you brew for? Studies from 1981, by Prof. Michael Spiro showed tea needs to brew in the pot for a minimum of 2 minutes. However even after 2 minutes, only 64% of caffeine has been removed from the leaves. In fact, it will take a whole 15 minutes of brewing to remove 100% of the caffeine. Further studies by Hicks et al. in 1996 shows it’s even worse for tea bags, with only 33% of caffeine being removed after 2 minutes. It is worth noting, caffeine levels vary naturally in types of tea and levels in one type may overlap with another type. All the types of tea are produced from the leaves of the Camellia sinensis plant, including including white, green and black teas. It is the differing processing methods which result in variations in tea type.
To conclude, there doesn’t seem to be a clear consensus on how to make the perfect cup of tea. There’s certainly areas where a cup of tea can be unquestioningly improved, such as by using tea leaves instead of a tea bag, but other areas are down to personal preference, such as whether to put milk or water in first, or whether to use sugar. But, however you take your tea, don’t take it from me, it’s mine.