Why does my tummy rumble?

Why does my tummy rumble?

I’m back with another great question this week, send in by Sarah, who wants to know …

Why does my tummy rumble?

It is all explained in this short video, just click to play (or, if you prefer, you can read the answer below).

While we sometimes find the noise a little embarrassing it is actually a really natural, and essential thing and shows that our bodies are working correctly, but why all the noise?

Let’s take a closer look!

The noises come from our digestive system, which is basically a long tube that stretches from out mouth to our anus! It usually comes from our stomach or small intestine.

The wall of this tube is mainly made up of muscles, called smooth muscles, which move in a certain way to push food through the system. This muscular movement is called peristalsis and this is how it works…

A small area of muscles contract, a bit like squeezing a ring around a part of the tube and this pushes things like foods, liquids and gases forward a little; then these muscles relax and the muscles in front of them contract and so on, pushing food and other content down the tube with each contraction.

Think about squeezing toothpaste from a tube!

The noises we hear are due to the movement of food, liquids and gases down the digestive tract. We associate the noise with an empty stomach, or being hungry, but the sounds are made when we have food in our system too. We often don’t notice them as the sound is dulled down.

When our digestive system is empty the noise is a lot louder.

It makes sense that peristalsis happens when we need to pass food through our digestive system, but why all the activity when our stomach is empty? Well this is the result of something called the Migrating Motor Complex or MMC for short!

This usually happens when our stomach and intestine have been empty for about two hours; a type of electrical pulse is triggered and this causes peristalsis through the digestive system. This serves a type of cleansing function; it clears any pockets of leftover food, mucus, bacteria and other debris from the stomach and small intestine.

The MMC response is usually triggered when our digestive system has been empty for about 2 hours

The MMC response is triggered every 90 to 120 minutes, until the next meal is eaten. It does tend to quieten down a bit while we sleep and then ramp up the activity again when we waken, which is why we often have gurgling tummies in the morning.

I hope you enjoyed this short explanation and video; Do let me know in the comments below and as always, if you have a question you’d like answered just leave it in the comments below! 

Are all raindrops the same size?

Are all raindrops the same size?

As you know, I love receiving your questions and I am always thinking of different ways to answer them. Some you will find in my regular column in the Irish Examiner, some I answer here on the blog, in written, video and info-graphic form.

Here is something a little bit different and I am hoping to make it a regular thing, so please let me know what you think and keep those questions coming!

Are all raindrops the same size?

In order to answer this question we need to first understand how raindrops are formed. And that story starts right down here on Earth. We have lots of water in the form of rivers, lakes and seas and when this water heats up it changes into a gas, called water vapour which rises up into the air.

The sky actually has lots of bits floating around in it – like dust and smoke particles. The water vapour tends to form tiny droplets of water around these little specks of dust and smoke and these droplets come together to make clouds.

At this stage the tiny drops are light enough to stay in the sky, but, as the cloud fills up with more and more of them they tend to start to bumping off each other and as they do they join together to form bigger droplets. Eventually they get so big and heavy that they can no longer stay in the cloud and they drop down towards the Earth as rain.

A water droplet needs to be at least ½ mm in diameter before it will fall as a raindrop.

Depending on how many droplets have joined together to make that raindrop, we already have drops of different sizes falling from the clouds.

What shape doe you think the raindrops are? Teardrop shaped maybe? No, not at all! Although raindrops are usually depicted in this teardrop shape they actually start off as nice round spheres. They have lots of forces acting on them, like surface tension which acts on the surface of the drop keeping it in that nice round shape.

As the rain drops fall they experience other forces too like air pressure. As it pushes from below and above the rain drops get squished into sausage like shapes until they eventually split into a number of small drops of various sizes and these are what fall to the ground.

So, are all raindrops the same size? Definitely not!

And they are not all teardrop shaped either.

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A big thanks to Ewan for sending in this question. Remember to keep sending in your questions. You can leave them in the comments below.

I’d love to know what you think of this video, there are lots of improvements I want to make and I’d love your comments and feedback.

 

The perfect pancake formula

The perfect pancake formula

We are big fans of pancakes in this house; I’m pretty casual with my batter making at this stage, I throw a few things into a bowl or blender, a bit of a mix, into the pan, quick flip and hey presto! It seems I am going about it all the wrong way. There are formulas that I should be following, such as…

  1. The batter formula

If you take your pancakes seriously, you’ll want the appearance to be just right. It’s not just luck or habit; it is all about the flour to liquid ratio, according to a group of researchers at University College London.

The thickness of the pancake determines the way the water in the pancake is released during cooking and ultimately determines the overall appearance of the finished product.

The experts devised a formula…

Mixture (ml) required per pancake : (D² x T x π) / 4

Total mixture (ml) required: (D² x T x π) / 4

… where D is the diameter of the pancake pan and T is the thickness that you want your pancakes!

And believe it or not, this pancake study has medical benefits too: the team are using what they learned to create better surgical methods for treating glaucoma, which is a build-up of pressure in the eyes caused by fluid.

pancake17

  1. The perfect batter calculator

If this all sounds a bit too complicated then don’t worry, maths students at the University of Sheffield have taken this formula and generated a calculator that does all the maths for you. All you need to do it type in how many pancakes you want, how thick you want them and how wide your pan is and voila, you get an exact recipe!

  1. The super formula

If you like your pancakes with some extra maths then don’t worry, there is a formula for you too, but hold on to your whisks, this one is pretty tricky!

100 – [10L – 7F + C(k – C) + T(m – T)]/(S – E)

Apparently, the closer you get to 100, the better the pancake.

L is the number of lumps in the batter; C is that consistency.

F stands for the flipping score, k is the ideal consistency of the batter and T is the temperature of the pan.

M is the ideal temp of pan is, S is the length of time the batter stands before cooking and E is the length of time the cooked pancake sits before eating.

Are you still with me? If not don’t worry. If everyone in your house is happy to eat your usual offerings then I’d go back to the old reliable. Me? I’m taking my inspiration from this post and I’m going to add some colour and sprinkles… without a calculator in site.

Whatever way you make your pancakes today, I hope you enjoy 🙂

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If you want to know a little more about your pancakes, from history, to ingredients, to science, check out my post over on Headstuff.org today!

How do snails get their shells and can slime mend a broken heart?

How do snails get their shells and can slime mend a broken heart?

It is all about snails here this week; snail questions, bad weather and midterm break. I was planning a written blog in response to all his questions, but, spirits were high this morning (in the kids, not me!) so writing time was limited. Instead we went for something a little different and if you like it, I think it could become a regular feature.

We made a little video, the snail questioning one and I. So go get a cuppa and settle down for five minutes with us… it’s time to TAKE FIVE!

So what do you think? We hope you liked it, let us know what you think in the comments below and, if you have a question you’d like covered in a TAKE FIVE video, let us know!

Have a great weekend!

Why do we lie?

Why do we lie?

I watched a great documentary on Netflix* recently all about lying… it is called Dis(honesty): the truth about lies and I would highly recommend it.


It really got me thinking about lying, why do we do it, what would happen if we don’t and is it a uniquely human activity?

First off, we all do it! If you are shaking your head in disagreement, then you’ve just lied too! Sometimes we do it for good reasons, sometimes just to save our skin, but we all lie from time to time. So why do we do it and is it a purely human activity?

WHY DO WE

We lie for a number of reasons, it may be a little white lie to make someone feel better or it might be a big lie for our own gain, or to save our skin!

Many of the lies we tell are to present a better side of ourselves; make ourselves appear a little nicer, a little smarter, or a little more popular. We don’t often even recognise these lies, we don’t realise we are doing it – we are lying to ourselves!

On a base level, we probably lie because evolution has shown us that it works to our benefit and the benefit of society. As our social connections have developed, so too have our abilities at lying. It is actually a valuable tool to have and brings with it many advantages. Lying is a sign of intelligence and is considered a complex cognitive skill.

Different types of lies and liars

There are different types of lies and different categories of liars! There are the little white lies that we all do, usually for social acceptance or compliance. There are lies of exaggeration, usually of little harm either;  and then there are the bigger lies that are often more serious and come with a lot more consequences if found out.

There are also different types of liars. We are all contributors to the pool of common-or-garden, everyday liars, but things get more serious when we look at the compulsive or pathological liar.

Compulsive liars tell lies as the norm, it is an automatic reflex and it takes a lot less effort for them than telling the truth does. Pathological liars tend to take it one step further; they lie for their own gain, with little thought to the consequences of their lies, for either themselves or others.

What happens in our brains when we lie?

Lying is a complex process; in order to do it our brains must focus on two opposing pieces of information at the same time: the truth and the lie. If we want to process or deliver a lie we need to believe that it could be true. The brain has to work much harder to lie than to tell the truth. Activity in the prefrontal cortex (at the front of the brain) has been shown to increase when a person lies. This is the part of the brain involved in decision making, cognitive planning and problem solving.

Usually when we tell a small lie, for personal gain, we feel bad. These emotions of regret and guilt are controlled by a part of the brain called the amygdala. However, the more we lie, the more we desensitize the amygdala so that it produces less of these bad feelings.

Studies on the brains of pathological liars show that they have about 25% more white matter in their prefrontal cortex, suggesting more connections between different parts of the brain. However, they also have about 14% less grey matter, the part that can help rationalise the potential consequences of each lie told.

No man has a good enough memory to be a successful liar- Abraham Lincoln

Do other animals lie?

Yes some do. One famous example that my children love to hear about is of Koko the gorilla. Koko is renowned for her sign language abilities, with an impressive vocabulary of more than 1000 words. Koko has a pet kitten that has come in handy for more than just cuddles and companionship. One day Koko tore a sink from a wall in her enclosure. When her carers returned and asked what happened, Koko signed ‘the cat did it!’

Koko The Gorilla2

When do we start lying and how often do we do it?

Some scientists believe that we begin the act of deception as young as six months old! This usually starts as fake crying, or smiling, to get attention. At that age we don’t do a very good job (although it is probably quite cute and amusing to watch) and we likely do not do it as a conscious lie.

By the age of two however, we have put in a little more practice and can deliver an outright lie with more commitment and conviction.

Adults are so good at lying that they can often lie even to themselves; on average, adults lie about 10 times a day and we can throw about three lies into a short conversation with a stranger, without even knowing we are doing it.

Are there ways to spot a lie?

Some of us are better liars than others and there is no detection system, including lie detectors, that work for all. However, many of us amateurs give away some tell-tale signs when we are lying, such as…

  • We make and keep direct eye contact (contrary to common held belief)
  • We keep our bodies very still, but we may…
  • jerk our heads a lot
  • We give more information than is necessary
  • We touch or cover our mouths with our fingers
  • We breathe at a more rapid rate
  • We cover vulnerable parts of our bodies, such as the throat, head or chest

Interestingly, we are better at lying when we lie for altruistic reasons than for our own good and these lies are more difficult to detect.

So that is the low-down on lying, and not a word of a lie 😉

Have you any facts or stories to add? I’d love to hear them, just leave them in the comments below.

*Disclosure: As a member of the Netflix Stream Team I have received a years subscription to Netflix, free of charge, and an Apple TV, for streaming purposes. As part of Netflix Stream Team I will be posting monthly updates on what we are watching and what is on offer.  All opinions expressed will be my own.

What would happen if we had no moon?

What would happen if we had no moon?

What would happen if we had no moon?

That was a questioned posed by one of my kids this week. It lead to lots of discussion and interesting debate until finally we were talking about werewolves!

moon

 photo credit: kendoman26 Not Quite There! via photopin (license)

Firstly, lets consider how the Moon got there in the first place.

The Moon is approximately 4.51 billion years, about 60 million years younger than the Solar System. It formed from the debris from created by a massive collision between a large asteroid (about the size of Mars) and the early Earth.

Originally the Moon spun on its own axis much more quickly than it does today, as did the Earth. However, over time the Moon’s spin slowed down. This is because the gravitational pull of the Earth on the Moon distorted its shape, making it bulge in the centre and ultimately (it took an estimated 1,000 years) it slowed it down until the speed at which is spun on its axis matched the rate at which it orbited the Earth. This is why we only see one face of the Moon. If you still find that hard to understand test it out with two balls or check out this great video by Minute Earth.

Almost all moons in our solar system spin on their axis at the same speed as they orbit their planet.

Of course the gravitational forces between the Earth and the Moon are not one sided, the Moon also has a gravitational pull on the Earth and this causes some obvious effects here on Earth, like the tides in our oceans and seas.

Not that we know how it got there, let’s consider what would happen if it suddenly disappeared.

  1. Darker nights

    Although the night sky would still be lit by so many stars in our galaxy we would definitely notice it darker without the Moon. The full Moon on a cloudless night provides enough light for us to navigate by, in fact we can nearly read by its light. On these nights the Moon is about 1500 times brighter than Venus, the next brightest object in our night sky.

  2. Shorter days

    Without the stabilizing effect of the Moon, the Earth would begin to spin more quickly. It is estimated that a day on Earth would eventually only be about eight hours long, meaning there would be about three times more days (1095) in a year. However, this effect would happen very, very slowly. How long?

  3. Less extremes between high and low tides

    The gravitational forces exerted by the Moon causes tides to rise and fall in our seas and ocean, this is called lunar tides. Without the Moon we would see a big drop in the difference between high tide levels and low tide levels. There would still be some tidal difference (as the Sun exerts a gravitational force too – solar tides) but it would be a lot less, maybe as much as 40% less than what we have now.

  4. A more extreme climate

    As mentioned above, the Earth would spin more quickly on its axis without the Moon around to slow it down. The Earth is also tilted slightly on its axis as it spins. At the moment the Earth is at a tilt of 23.5 degrees on its axis. The Earth’s tilt can wobble slightly, but, due to the Moon, it never stays between 22 and 26 degrees. Without the stabilising forces of the Moon the Earth would wobble a lot more as it spins. This would lead to changes in our seasons. Sometimes it would tilt too far, resulting in extremes of temperatures and seasons. Sometimes there would be no tilt at all, meaning no seasons at all. Whatever way it goes, we would certainly find some extremes in our weather conditions if we had no Moon.

  5. No solar eclipse

    A solar eclipse happens when the Moon gets between the Sun and the Earth, casting a shadow over the Earth. There are different types of solar eclipses, but a complete solar eclipse is quite a spectacular show, the entire sun can be blocked briefly by a full moon, causing complete darkness from the correct viewpoint on Earth. Without a Moon, these spectacles (which can occur somewhere on earth every 18 months or so) would cease! Of course  lunar eclipses would no longer exist either; A lunar eclipse occurs when the Sun, Earth and Moon align with the Earth in the middle, casting a complete shadow on the Moon and preventing any of the Sun’s light from reflecting off it .

  6. No Werewolves!

    We are back to the werewolves. My kids put up a good argument that without a moon Were-people could not change into Werewolves, and they therefore wouldn’t exist. I know better than to argue with that one!

*****

If your questions expand beyond the Moon why not check out my Appliance of Science column in today’s Irish Examiner where I answer questions on the Universe and beyond.

Can water go uphill? A rainbow water experiment

Can water go uphill? A rainbow water experiment

Can water go uphill? The answer is… yes it can! In some ways anyway; water can travel upwards by a process called capillary action.

Capillary action can be described as water climbing upwards due to weak forces created between the water molecules and the material the water moves up along, or through. In the experiment below the water travels up the paper towel, forming these forces with the paper towel as it creeps upwards.

For this experiment you will need…

  • six clear cups or bottles
  • six pieces of paper towel, folded length-ways into long strips
  • A jug of water
  • Food colouring… red, yellow and blue

What you do…

We arranged our six bottles in a circle (but you could do this in a straight line too, if you want to create the same colours as us, you will need seven bottles in a straight line, with one colour repeated… think about it 😉 )

Half fill every second bottle with water, leave the other bottles in between empty.

Add a few drops of food colouring to each bottle containing water, red in one, yellow in the next and blue in the next.

Now take a piece of the folded paper towel and place one end into the bottle containing red-coloured water, and the other end into the empty bottle beside it; make sure the paper towel sits into the coloured water.

Take another paper towel and place one end in the empty bottle (that is now connected to the red-coloured water bottle) and the other end into the bottle containing yellow-coloured water.

Repeat this all around the circle so that the paper towel ‘wick’ goes from the yellow-coloured water bottle to an empty bottle and another from that empty bottle to the blue-coloured water bottle; finally place a paper towel ‘wick’ from the blue-coloured water bottle to an empty bottle and another from that empty bottle to the red-coloured water bottle.

When all set up it will look like this…

walking-water-1

walking-water-2

Then all you have to do is wait! You should see the water starting to climb up the paper towel ‘wicks’ within a few minutes. Leave the experiment for a few hours or overnight to get the final result.

Results:

Eventually the water will travel up one side of the paper towel and down the other side, starting to fill the empty bottle. As water comes into the empty bottle from each side, the two colours of water will mix.

The red and yellow-coloured waters will mix in the bottle between them, creating orange-coloured water.

walking-water-4b

The yellow and blue-coloured waters will mix in the bottle between them, creating green-coloured water.

walking-water-3b

The blue and red-coloured waters will mix in the bottle between them, creating indigo-coloured water.

walking-water-5

You will notice that all the bottles have now got about the same amount of water in them. Once this happens no more water will transfer between bottles.

walking-water-7b

walking-water-6

What is happening?

As mentioned above, the water is able to climb up the paper towel due to these forces, called adhesive forces, that form between the water molecules and the paper towel.  This process is called capillary action.

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On the subject of water, if you ever wondered why our fingers wrinkle in the bath check out my recent Appliance of Science column in the Irish Examiner. 

New Kids’ Science TV show – Is Eolaí Mé

New Kids’ Science TV show – Is Eolaí Mé

I am delighted to tell you that Is Eolaí Mé is starting next Tuesday 20th September, on Cúla 4, TG4, at 17.25pm. It has been almost a year since filming of the show wrapped, you can take a look at my behind the scenes account here. As consultant and script writer on the show, I am extremely excited to be able to finally watch it on TV.

Here is a little preview…

What to expect

Each show will be jam packed with lots of amazing Science. The presenters, Una and Peadar will explore a different theme each week… and explore is definitely the right word to use; they will be out and about finding fun ways that science is used in real life. From rocket launching to surviving an indoor storm and so much more in between. I

Is Eolaí Mé is presented by Peadar Ó Goill & Úna Ní Fhlatharta and produced by Fíbín.

Each week Una will be joined by a group of children, keen to help her roaming reporting on the science topic of the day.

iemuna2cnamharlach

When Peadar is not out testing his endurance skills in the name of science, he will be in his amazing loft lab, testing theories, trying out the latest experiments and even sharing ones to do at home.

iempeadar1

Peadar will be joined in his loft by some amazing young scientists who are always up for the adrenaline-pumped science challenge of the day.

Then there are the antics of An t-Ollamh Ullamh and his reluctant side-kick, Aodh, that will definitely add an hilarious comic angle to each programme.

And all that is only the tip of the iceburg, you will be amazed at just how much science is packed into the half-hour programme. So set your alarm clocks, tell your parents and teachers and get ready for kick off next Tuesday! The show will air twice a week, for double the fun; Tuesdays and Thursday at 17.25, and, of course, also available on TG4/Cúla 4 player.

I’ll leave you with this little video… showing Peadar running across a bath of white liquid! How does he do it? You’ll have to tune in to find out!

Check it out… Is Eolaí Mé, every Tuesday and Thursday, 17.25 on Culá 4, TG4. Starting 20th September, 2016.

 

 

In your Dreams – the science of why, how and when we dream

In your Dreams – the science of why, how and when we dream

Dreams, we all have them, some we remember, some we don’t! There are those who want to analyse every detail of their dreams, seeing them as portents to future events or windows into our souls. Some dismiss dreams as a nothing more than random images as a byproduct of brain activity.

Regardless of what camp of dream analysis you belong to, you may like to know a bit more about the why, how and when of dreams, to fill in the blanks and give a better understanding of what happens when we close our eyes at night.

dreams-header

 

Are there different types of dreams?

Dreams are a series of images, emotions, senses or events that we experience while we sleep. They are created in the brain, during different brain impulses and can last from a few seconds, to more than half an hour. There are a number of different types of dreams, the classifications vary depending on who you talk to, but in general we experience regular dreams, lucid dreams and nightmares.

The three basic types of dreams are…

  • Regular dreams usually occur when we are in a deep sleep phase, such as the REM (Rapid Eye Movement) stage of sleep.
  • Lucid dreams usually occur when we are in a lighter stage of sleep. We are at least partially aware that we are dreaming and we can consciously change the course of the dream if we so choose.
  • We are all familiar with nightmares and they are not just for children. They are dreams that evoke strong emotions and reactions within us, usually fear, terror, anger or anxiety.

What happens when we dream?

In order to talk about dreaming we must first look at what happens when we sleep and the different stages involved. There are five stages of sleep, stages 1, 2, 3, 4 and the Rapid Eye Movement (REM) stage.

We pass from each stage of sleep sequentially, usually falling into a deeper sleep with each stage. Once we have completed a full cycle (stages 1, 2, 3, 4 and REM) we return to the first stage and the cycle repeats. A full cycle takes between 90 and 110 minutes.

Stage 1

This is a very light stage of sleep, our bodies relax, our muscle activity slows and we experience slow eye movement.

Stage 2

Our eye movements stop, our muscle movements reduce and our brain waves slow down; Our heart rates slow and our body temeratures drop a little. We also experience burst of rapid brain wave activity in this stage, these are called brain spindles. Adults spend about 50% of their sleep time in this stage, this reduces with age.

Stage 3

We enter deep sleep, with some periods of very slow brain waves recorded.

Stage 4

The periods of very slow brain waves extend.

REM Stage

Our eye movement becomes erratic and jerky, our heart rates rise, breathing becomes more rapid and our limbs become temporarily paralysed. We spend about 20-25% of our sleep time in this stage (infants can spend up to 50% of sleep in the REM stage).

The REM stage of the first cycle of sleep is fairly short (about ten minutes) but increases in duration with each cycle (up to an hour in the final cycle).

Stages 1 to 4 of sleep are collectively referred to as the non-REM stages (NREM).

We dream at all stages of sleep but most of our dreams are thought to occur during the REM stage. Studies show that we tend to have different types of dreams at different stages of sleep; In the early stages, we have very short dreams but they are more realistic and relatable. As we move into deeper sleep our dreams tend to become more fragmented. As the night progresses and we experience longer REM states our dreams become more obscure and disjointed.

dream-quote

 

Why do we dream?

There are a number of theories as to why we dream, but scientists are still not sure. Some say that dreaming is an asinine activity that serves no purpose, but most agree that this is not the case, although they may argue as to the true value of dreams.

Dreaming has no purpose at all

In 1977 psychiatrists J. Allan Hobson and R.W. McCarley theorised that dreams don’t actually mean anything at all. They called their theory the ‘activation-synthesis hypothesis’ and stated that dreams are merely electrical brain impulses that pull random thoughts and imagery from our memories.

Dreaming is an ancient biological defence mechanism

Evolutionary biologists studying dreams and their function have proposed the Threat Simulating Theory (TST) of dreaming.

The threat simulation theory of dreaming states that dream consciousness is essentially an ancient biological defence mechanism, evolutionary selected for its capacity to repeatedly simulate threatening events.

Basically, dreams are seen as a simulation, a way to prepare our bodies and hone our skills for the right response in potentially threatening situations. By experiences threats and events in our mind (like being chased by a wild animal!) we can train our bodies to respond correctly if or when the threat really does appear in real life. We can develop our neuro-cognitive mechanisms.

The TST also suggests that people under threat in their everyday lives will dream more, as a way to exercise and prepare for the dangers they may experience each day. There is some evidence to suggest this is the case.

Scientists in favour of this theory also quote the fact that a convincing 70% of our dreams are made up of such threatening scenarios.

Dreams help us solve problems

It is possible that dreams help us unravel and review all the complexities we have experienced during our waking hours. Without the restrains of our conscious, logical thinking we can view things from a completely different angle. Some people can wake after a night of sleep with their eureka moment, solving a niggling problem, literally while they catch some z’s. Perhaps the most famous case is that of the chemist August Kekule, who supposedly discovered the benzene ring structure after dreaming of atoms linking together in a chain and then twisting, like a snake biting his own tail, into a ring structure.

The famous American writer, John Steinbeck called this the ‘committee of sleep‘…

It is a common experience that a problem difficult at night is resolved in the morning after the committee of sleep has worked on it

How does all this free thinking work? Daytime events and often recorded in fragmented forms in different regions of the brain. The ‘memory’ is held together by interaction of those brain parts with the hippocampus. During certain stages of sleep these connections are lost, but brain activity in each of these regions may continue. This ‘untethered’ brain activity can provide the freedom of thought and creativity that is constrained in the waking hours.

We dream to fulfil our desires

This brings us back to Freud who believed that our dreams were a manifestation of our basic, unconscious desires and urges. He believed that to better understand our own psychological makeup, and issues, we needed to record and analyse the content of our dreams.

We dream to help us process our emotions

Do we dream to help us process emotional events in a safe way? When we sleep the levels of certain stress hormones  in our bodies are reduced, therefore we can reflect on a stressful situation or event, in a safe place, where the stress response has been toned down.

Studies have observed high activity in the amygdala during the REM stage of sleep. This is the area of the brain associated with emotions. This suggests that, while sleeping, our brains access emotional events and memories while the stress neurochemicals (norepinephrine) are suppressed, allowing us to process and resolve any emotions or traumas. We wake feeling better about an event that may have caused us stress the day before.

Dreaming is an important part of our memory storing process

The process of dreaming may help us strengthen, connect and store memories. In order to full consolidate our memories we need to strengthen links between different areas of the brain that have recorded information from the memory, and to integrate the information with previously stored knowledge.

The most basic function of dreaming consists of connecting new material with old material in memory systems; reorganising the memory systems, guided by emotion. (Hartmann, 2011).

Sleep creates an optimal  environment to allow memory links to be repeatedly activated without the interference of external stimuli. This reactivation strengthens the neurological pathways that link the various parts of the memory as well as creating links with older memories and learning.

MRI studies have shown that brain areas associated with short and long term memory consolidation (hippocampus and amygdala) are activated while we dream.

Different types of memories may be consolidated at different stages of sleep; the episodic memories are best processed during NREM stages, while more sensory, procedural and emotional events are likely integrated during REM stages.

 

How long do dreams last?

Dream length varies, but on average our dreams start off short and get longer as the night progresses. Although some dreams may only last for seconds, our first dream of the night is usually about five minute long, our last dream can be as long as 45 minutes. As most of our dreaming occurring during the REM stage of sleep, as this stage gets longer, so too do our dreams.

Most people have at least two to three dreams per night, with the average being six to seven. We spend about two hours a night dreaming, which can add up to a whopping six years of dreaming in a lifetime!

 

These theories and insights are fascinating but there is still much to learn. Scientists will continue to research, study and debate the importance of the dreaming process, but, looking at how much of our lives we spend dreaming it is certainly a worthwhile study. 

 

dream-facts

 

 

What do Forrest Gump, horses and music have in common?

What do Forrest Gump, horses and music have in common?

What kind of music do animals like? Can cows tell the difference between classical and rap? Which animals are partial to a bit of REM and what do Forrest Gump, horses and music have in common? Science has the answers!

Before my first child could even speak we had noted her reaction to music. Just having the radio on in the background we often observed a change in her posture or mood depending on what was playing; in fact, we frequently had to turn off the radio when a slow or sad tune would reduce her to tears.

This has fascinated me ever since, from the effect of music on our mood, our health, and our brain development. I never gave much thought though to the effect, if any, of music on animals. That is, until today. A good friend called round for a chat and fascinated me with something she had heard on the radio about the effect of  the theme tune to Forrest Gump on the emotional state of horses. My interest was piqued. With a little research, it seems many animals respond in different ways to different types of music, just as we do. And for the animals that have no interest in ‘human’ music at all… there is now species-specific music created just for them!

Music with a Meow in mind

It would appear that cats are not terribly impressed with any of the music composed for our human ears. They show little or no reaction to it. However, this prompted a small team of scientists (Snowdon and Savage) and a composer, David Teie, to look at just what might appeal to our feline friends. With much study and research, they created music with cats in mind, composed of tones, pitches and frequencies that would most appeal to cats, and mimic what is in their natural environment. They have reported that the cats they studies showed an increased interest and preference in the species-specific music (with greater positive responses in younger and older cats when compared to middle-aged cats).

REM keeps these cows ‘udderly’ content

Many farmers know that playing music to their cows keeps them calm and happy during milking. In 2001 a study run by a group of Psychologists from the University of  Leicester, UK,  played music of different tempos to herds of more than 1,000 Friesian cattle. The results were impressive: they played a variety of music, from slow, classical, techno and rap to the animals for 12 hours a day, over nine weeks. While they found no increase in milk yield when playing fast tracks to the cows, they reported a 3% increase in each animal when slow music was played; that is about 3/4 of a litre or one and 1/2 pints of milk extra per cow, per day.

What tunes did the cows seem to enjoy the most? “Everybody hurt” by REM and “Bridge over troubled water” by Simon and Garfunkel were apparently popular for increasing milk yield and keeping the ladies calm!

Based on this knowledge, the British Columbia Dairy Association decided to jazz things up a little by inviting people to compose some mellow cow tunes and enter them into their “Music makes More Milk” contest. Finalists had to impress the jury of five Holstein cows. The winning tune (if you really need to know) was titled “A Moo down Milk Lane”.

cow

Image source:pixabay.com

Moving on from bovine Moosic we finally come to the horse part of this story! What do our equine friends think of our human music?

Music keeps them ‘stable’

A 2015 study on purebred Arabian race horses looked at the emotional and performance levels of the horses when exposed to classical music in the stable area. The initial results of the study suggested that the horses exposed to classical music exhibited reduced stress levels (determined by measuring cardiac activity variables) and an increase in performance (as measured by their overall wins). These observations peaked at the two to three-month phase of the study and then dropped back to normal levels over time (suggesting that the horses became accustomed to the music and it had less effect).

Horse at stable door

photo credit: What you looking at? via photopin (license)

The music used in the study was specifically composed with horses in mind. What about human music?

That’s a ‘neigh’ for jazz

A 2013 study tested horses’ emotional responses to classical, country, rock and jazz. The results from this small study suggested that classical and country music had the most calming effect on the animals tested and the fast tempos and minor keys of the jazz music put the animals more on edge.

Then someone decided to try a little Forrest Gump theme music! (Finally!!)

Trot Forrest Trot!

From specific genre to a specific piece of music… the Forrest Gump theme tune. This classical piece, by Alan Silvestri, was chosen for its ‘repeatability’. The study was carried out using horse from the French National Stud. 48 horses were fitted with newly designed horse headphones; half of the horses were played the Forrest Gump theme tune while travelling in horseboxes; the other half were played the music while being shod by a farrier. Both these events will typically increase stress indicators in the animals.

And the results? The horses that were played music during transport showed the greatest reduction in stress indicators. This could be very good news for trainers and owners of horses that often have to travel internationally for events. The effect in the animals that were being shod was less effective, although both groups showed a quicker heart rate recovery afterwards.

Personally, I find these results fascinating. I grew up around horses and found them very sensitive creatures, in tune with everything in their surroundings. I love the idea of reducing their stress in any way possible. And I listened to the Forrest Gump theme tune while I wrote this piece, it certainly brought me to my calm place!

Have a listen.

What do you think? Have you ever noticed a pet respond to a particular type of music? What kind of music was it? Or what favourite piece would you like to see used in these experiments? Have you any favourite animal music stories of your own? Let us know in the comments below!