Tag Archives: psychology

The Basics of Alzheimer’s Disease

Today is World Alzheimer’s Day, a day to raise awareness for a disease that is likely to affect 1 million people in the UK by the year 2025. To mark the day, our Social Media Intern and Neuroscience student, Charlie Wilkinson has written a guest post for us:

Alzheimer’s disease is a devastating neurodegenerative condition involving the death of nerve cells (neurones) in the brain, and the subsequent break down of communication between synapses.

Affecting millions worldwide, Alzheimer’s Disease is the most common form of dementia in the elderly, affecting 850,000 people in the UK alone. The disease is associated with serious cognitive decline, including typical memory and language impairment. The disease has now overtaken heart disease as the leading cause of death in women.

The biological mechanisms that underpin the development of Alzheimer’s Disease can be boiled down to the formation of plaques, and tangles. The development of the condition is a result of faulty mechanisms in the brain for the breakdown of a specific protein.

Plaques 

Amyloid Precursor Protein (APP)  is a protein found abundantly in the brain, stuck in the membranes of neurones. The function of the protein is largely unknown, but the way this protein is broken down is the critical early event in Alzheimer’s Disease.

Proteins like APP are made up of many small units known as amino acids; enzymes have the ability to break down proteins by cutting at specific amino acid sites. If the APP protein is cut by one enzyme (alpha), the protein that’s formed is healthy and soluble. If however, APP is cleaved by another enzyme (beta), the protein that’s formed is diseased and insoluble. This diseased protein is known as beta-amyloid.

As more of this beta-amyloid protein is formed, the proteins start to stick together or aggregate, forming senile plaques. Although the way these plaques cause damage isn’t fully understood, it is theorised that the body reacting to the plaques with an inflammatory response leads to damage of neuronal cells in the brain, which is the typical symptom of Alzheimer’s Disease.

Tangles

The other proteins typically associated with Alzheimer’s Disease are neurofibrillary tangles. Tangles are formed through twisted fibres, formed as small protein units called ‘tau’ which stick together inside neurones.

The tau proteins are usually associated with the transport system inside these cells – nutrients are important for the function of these nerve cells, and transport systems supported by tau are important in moving nutrient and other supplies around the cell.

When tangles form using tau proteins, these transport systems essentially malfunction meaning nutrients and other essential products can’t be transported around the cell and the cell starts to die.

There is no cure for Alzheimer’s Disease, and treatments can only target the cognitive decline and other symptoms associated with the disease. Treatments for the condition, however, are becoming ever more effective targeting different aspects of the disease. The determination of researchers to develop treatments to reduce the burden of the disease in sufferers, is encouraging for the future of Alzheimer’s disease.

The 21st September 2017 is world Alzheimer’s day. For more information about Alzheimer’s Disease and to find out how you can help combat this illness visit the Alzheimer’s Society here.

 

#TryThisTuesday: Valentine’s Day Optical Illusion

Happy Valentine’s Day! Love can confuse your brain, and so does this week’s Try This Tuesday.

You don’t need any equipment to try this experiment at home – you just need to stare at your screen, or more specifically the + in the middle of the picture below. You can blink but don’t look away.

heart-optical-illusion

If you stare long enough the pink dots should disappear!

The Science

It looks like the pink dots have disappeared due to a visual phenomenon called Troxler’s fading or Troxler’s effect. if you fix your eyes on a certain point, then anything in your peripheral vision will fade away and disappear after about 20 seconds. In this experiment our sight was focused on the + in the middle of the screen and the the pink dots in your periphery slowly fade and finally disappear. It works especially well in this experiment at there is such low contrast between the light pink dots and the grey background.

This is a type of optical illusion. If you want to see another, have a look at our spinning disk Try This Tuesday.

 

#TryThisTuesday: Spinning Disk

This Tuesday, you don’t need any equipment to try this experiment at home – you just need to stare at your screen, or more specifically the video clip below:

(don’t worry we aren’t trying to hypnotise you!)

Stare in the dot in the middle of the circle for 20 seconds, you can blink but don’t look away, keep your eyes focused there. After 20 seconds look at someone’s face, if there’s no one around you, get a face up on screen that you can quickly look at.

What did you see?

Hopefully, if it worked you should have seen the face appearing to get bigger. Obviously, it didn’t really grow before your eyes, this is simply an optical illusion playing a trick on your brain.

You see things because your eyes send messages to your brain about different types of light, shapes and movement and your brain makes up an image of the world around you. When you stare at the spinning disk for so long, your eyes continually send messages to you brain to say its spinning. Your brain gets a bit bored of hearing the same message over and over again so kind of stops listening, tunes out the messages and just assumes from now on, this is how it is – everything is spinning.

So when you look away at a face or your hands or anything really, your brain thinks it should be spinning so gets confused and spins the image in the opposite direction, making it appear to grow. After a few seconds, your brain will hopefully catch up and everything will go back to normal.

Top Revision Tips: Get some sleep!

With exam season upon us, we thought we would help you guys out a little bit with a useful piece of procrastination – revision tips backed up with scientific research!

1. Get a good night’s sleep

We spend on average one third of our lives asleep so it must be important. There have been millions of studies looking into sleep and how it effects our minds and bodies.

Sleep is divided into five stages. The final stage is called REM (Rapid Eye Movement) sleep, named after the quick eye movements made during it. If you look at someone who is in this stage of sleep you will be able to see their eyes moving behind their eyelids (it’s not creepy if it’s for science). During this stage your brain is super active, brain scans during this phase look similar to someone who is awake but your body is paralysed. This stage is considered to be the point at which you consolidate memories into long-term memories.

Scientists in Italy looked at a range of studies focusing on the effects of sleep on the academic performance of students. The results showed students whose sleep was restricted did worse than usual in exams whereas those who were allowed extra sleep performed better. Further to this, a study by Trockel (2010) looked at lots of variables in 200 students and found those that woke up later performed worse in exams. So you might want to avoid the lie-ins during the exam period!

 

2. Don’t pull an all-nighter

Although it can be tempting to stay up all night to get some last minute revision in when you’re particularly worried about an exam, I wouldn’t recommend it. Research from Pilcher and Huffcutt (1996) looked at 19 different studies and found sleep deprivation (going a long time without sleeping) can impair your thinking and this is not going to help you in any exam.

The world record for the longest time kept awake without drugs is 11 days and 24 minutes (please don’t attempt to break this record). The record was set by Randy Gardner is 1964 and the severe lack of sleep not only effected his concentration and memory but also led to paranoia and even hallucinations. Of course this is an extreme example but studies looking at just 24 hours without sleep have found worse performance on memory tasks and slower responses after sleep deprivation. Not ideal for an exam.

3. Don’t rely on coffee

Coffee may seem harmless enough but it does contain a drug – caffeine. Although it does have its perks, as with any drug there are side effects that you won’t want around exam time. Firstly, I’ll explain the science behind what caffeine actually does once it’s inside your body. Within your body you have a molecule called adenosine which suppresses arousal and promotes sleep when it binds to its receptors. Caffeine is able to bind to adenosine receptors but does not trigger them, instead it simply sits there and blocks adenosine getting to the receptors so causes the reverse effects. This is clearly beneficial when you want to stay awake but can cause insomnia – not good as you now are well aware how important sleep is. Caffeine also stimulates the release of adrenaline – this already happens when you’re stressed so can worsen the effects and cause anxiety.

So what does the research say? Harrison and Horne (2010) conducted a study in which they deprived participants of sleep and subjected them to memory tests, some with coffee, and some without. They found those who drank coffee felt less sleepy but performed no better in their tests. Even in control conditions where participants weren’t sleep deprived, coffee made no significant improvement in their results.

If you are starting to lag with your revision and feel a little sleepy, try having a nap instead of reaching for the coffee. One study found that having a 60-90 minute nap can improve your memory recall and learning ability much better that a cup of coffee.

 

4. Manage your time well

Good time management is key to making sure you cover all the topics you need to before an exam and still leave yourself enough time for a good snooze. It can help you keep calm as well if you know you have given yourself enough time. A study of 249 students found that time management behaviours such as planning, organising, setting goals and prioritising helped reduce stress levels better than leisure activities – although leisure activities also helped reduce stress, so make time for fun when creating your revision timetable.

But it’s not enough to just make your revision timetable – you obviously have to stick to it. Another study found that self-discipline is a major predictor of academic performance.

So make a plan, stick to it and get some sleep!

Top Revision Tips: Memory Techniques

With exam season upon us, we thought we would help you guys out a little bit with a useful piece of procrastination – revision tips backed up with scientific research!

1. Don’t keep re-reading – test yourself!

Most scientific models of how memory works agree that we have a short term and long term memory. Short term memory can hold 5-9 items whereas long term memory has a much greater capacity but not everything we see, hear or read ends up there. To help embed things in our long term memory it helps to rehearse them and practice retrieval too. This means that whilst re-reading the same notes over and over again will help rehearse them, it is also important to test yourself to see how much of it you can remember to be sure you can retrieve these memories when you need them.

2. Use Mnemonics

Mnemonics are a technique used to help remember things by association. For example you might have learnt the order of the colours of the rainbow with the phrase “Richard Of York Gave Battle In Vain” with the first letter of each letter corresponding to the first letter of the colour it represents. So it translates to red, orange, yellow, green, blue, indigo, violet. Or maybe you learnt the compass points with “Never Eat Shredded Wheat”.

If you have to remember things in a certain order for your exam, making up a mnemonic like this can be a great way to help you. Mnemonics work by creating more meaningful associations and giving you cues to help you retrieve the information from your long term memory. Researchers Shetty and Srinivasan looked into the study skills of 137 Dental students and found that the use of mnemonics were associated with higher exam scores.

Here’s a mnemonic to help you remember the geological time periods:

geology

If you use mnemonics to aid your revision, comment and let us know what they are – you might be able to help someone else out too!

3. Don’t rely on cramming

It’s a classic scene – just before you’re about to enter an exam, everyone is sat around stressing over their textbooks and flicking through sheets of scruffy notes trying to get in some very last minute revision. Is this really helpful? Studies have shown that you can generally hold, on average, 7 things in your short term memory and this fades after 30 seconds if not rehearsed and committed to long term memory. Therefore it’s unlikely you’ll remember much of what you read waiting outside the hall after you have taken your seat and read the question.

It’s much better to manage your time to allow yourself to cover everything you need properly and get it into your long term memory before the day of your exam!

4. Use Chunking

Despite the fact I have just said you can only remember around 7 things in short term memory, you can probably remember a phone number or a couple of post codes for 30 seconds right? This is because, whether you notice it or not – that information is chunked, making it much easier to remember. This is why phone numbers are usually displayed with a gap after three or four numbers and why post codes are in two parts.

Chunking, or separating your revision into relevant sections can help you digest everything and remember it more easily. If you can create links between different bits of information and put them in meaningful categories it can help you to recall the relevant information in your exams.memory

 

memory

Why Perfumes are not the Perfect Christmas Present…

Many animals rely heavily on their sense of smell for finding food, getting a whiff of the competition and even sniffing potential mates. You might not often see humans checking the scent of their partners, but scientists have found it does play a subtle role in helping us chose mates – as do perfumes.

All animals are made up of a collection of genes that are inherited from parents, these code for all sorts of things like eye colour and taste buds. All mammals, including us, have a section of genes called the major histocompatibility complex (MHC) which affects how well your immune system fights diseases. It is also linked to your natural scent.

There have been experiments on mice, mandrills, meerkats and many other animals showing that females tend to mate with males that have a different MHC to their own. This ensures that their offspring have a more varied set of genes and so will likely have a better immune system and survive for longer – which is what every parent wants for their child.

When tested in humans, the usual method is to get a group of men to wear a t-shirt for several days to get it nice and sweaty and smelly. Women will then smell each of the t-shirts and rate the odours in order of which they find the most pleasant. These experiments have consistently found that women tend to prefer the scent of men with MHC genes different to their own.

So what happens when you wear perfume and cover up that lovely natural odour of yours? Two researchers, Wedekind and Milinski wanted to find out. They asked over 100 people to rate a selection of perfumes based on whether they would like to smell like that. They found a correlation between the type of MHC and the scents selected, suggesting that we choose perfumes for ourselves that will enhance our natural odour. However, when asked to rate perfumes based on whether they would like their partner to smell like that, they found no significant link.

It appears that we are great a picking out odours for ourselves, but not so much at selecting the perfect perfume for others. Maybe a gift card would be better this year…

perfume

 

 

The Science of Fireworks

We all know the history of Bonfire Night, but do you know the science?

The Explosion

All fireworks are essentially a combustion reaction, like fire, that produces light and heat.

Fireworks tend to have a long fuse that burns slowly so you have time to light the fuse and run away before the big bang! The fuse first reaches a compartment containing gunpowder, it ignites this causing the firework to launch into the night. There is a delayed fuse to ignite the next explosion, this heats the “stars”.

The stars in a firework are individual compartments containing a different composition of chemicals, depending on the desired colour and effect of the firework. The stars may even be arranged inside the shell of the firework so that they burst in a certain formation to form a shape.

The Colours

Firework displays always use a range of striking colours, the variety of colours comes from the use of different chemicals. Elements such as barium, copper and lithium burn with a coloured flame and are chosen for use in fireworks due to the bright colours they produce.

fireworks

The Sound

When the chemicals inside the firework’s shell are heated they convert from a solid to a gas. The gas takes up more space than there is available inside the shell so it bursts out creating a loud BANG.

Crackling noises come from fireworks which contain lead. When lead oxide is heated and vapourised, the vapour atoms produce crackling noises.

The whistling sound that you hear when the fireworks shoot up in the air, comes from the firework tube itself, not the chemicals. When the tube is partly empty, it will vibrate the air passing through it, causing a whistle.

How can you write your name with a sparkler?

I’m sure you’ve all held a lit sparkler at some point and twirled it around in the air to see a trail of light lingering in the air for a few seconds. The truth is the light isn’t really still there but your eyes play a trick on your brain to make you think that it is. Image resultOur eyes don’t react as quickly as you might think when our view changes, they usually keep the old view around for a fraction of a second. This is known as visual persistence and it’s what allows us to view a series of still images as movement. The effect is increased in the case of the sparklers due to the very bright light emitted form the sparks contrasting against the dark background. This makes the light appear to last longer.

 

fireworks

The Chemistry of Being Scared

Happy Halloween! We all like being scared sometimes, whether it’s scary movies or a rollercoaster, but why do we get scared?

We feel fear when we see or hear something that makes us anticipate harm. If you are walking through a haunted house this Halloween and a skeleton jumps out at you, the skeleton is a stimulus that triggers a signal in your brain.

The hypothalamus is part of your brain that activates the ‘fight or flight’ response. When you are scared molecules of glutamate (a neurotransmitter) travel to the hypothalamus. This then triggers the autonomic nervous system, a response that you can’t control.

brain

Nerves from the brain carry impulses to glands which produce adrenaline, released into the blood. Adrenaline causes our heart rate and blood pressure to increase making us ready to run away quickly.

When we get scared we also get goosebumps. This is a trait that evolved in our hairier ancestors. When our hair stands up on end it makes us look bigger and more threatening to whoever is scaring us. This is seen in other animals too, such as cats.

However, we aren’t scared forever. Eventually our body realises that there is nothing to be worried about.  Sensory data of what we have seen and heard is sent to the hippocampus in the brain which can store and retrieve conscious memories. It gives context to what we have seen and asks questions such as have I seen this before and what happened last time?

If a skeleton jumps out, we will realise that it isn’t real and is probably just someone dressed up! The hippocampus will determine that there is no danger and sends a message to the hypothalamus. Adrenaline production stops and our heart rate goes back to normal.

thinking

We have evolved to feel fear to allow us to survive. People and animals who feared the right things survived and passed on their genes. This makes sure we don’t do stupid things like picking up poisonous snakes or walking off buildings.

halloween

9 Scientific Mistakes in Disney and Pixar

Sorry to crush your dreams but we have inspected some of our favourite Disney films and some things just don’t sit right in our scientific minds. Here are nine examples of what would really happen, according to science. But remember anything is possible in the world of Disney…

1. Finding Nemo

All clown fish are born male. Each group of clown fish has one female, the biggest fish. When the female dies, the biggest male fish will become female, this is know as being a sequential hermaphrodite.  When Nemo’s mother was killed by the barracuda, Marlin would have become female, leaving Nemo as the dominant male.

finding-nemo

2. The Lion King

Rafiki is introduced to us in the Lion King, where he performs Simba’s birth ceremony. He also sings a song in the film “Asante sana, squash banana, wewe nugu, mimi hapana”. This is a Swahili rhyme which translates to “Thank you very much (squash banana), you’re a baboon and I’m not!”. Rafiki doesn’t belong to any species, he is a cross between a mandrill and a baboon, he has the colourful nose and cheeks of a mandrill and the mane and long tail of a baboon.

3. Up

In the film Up, Carl ties thousands of balloons to his house to go on an adventure to South America. However, the number of balloons he uses are not enough to lift a house. Estimating that the house weighs 45,000 kg, you would need over 3 million balloons!

up_movie_balloons_house-wide

4. Inside Out

Inside Out personifies five major emotions; Joy, Sadness, Fear, Anger and Disgust which all work together to guide and protect their human (Riley). However, there are actually six core emotions, with Disney missing out surprise. These six emotions are found to be universally recognized and expressed across the world, even in remote tribes that would not have learned the meaning of such facial expressions elsewhere.

inside-out-pixar-disney

5. Tarzan

After baby Tarzan was left alone in the jungle to be raised by gorillas, he eventually grows up and meets Jane who teaches him to speak English. Unfortunately in the real world, no matter how great a teacher Jane was, Tarzan would never have been able to talk. Scientists have described a critical period up to the age of 5 which is vital for language development. If children, like Tarzan, aren’t exposed to a human language in this time they will be unable to learn to speak later in life.

tarzan

6. Aladdin

Aladdin and Jasmine travel from Cairo (Egypt) to Athens (Greece) in one second on the magic carpet, meaning they would have to travel at 621 miles per second! The air resistance would be 100 million times larger than their weight, causing them to burn up, like when meteors burn up when they enter our atmosphere.

aladdin-1992

7. Star Wars

Star Wars is well know for its fights in space, full of explosions, blaster and engine sounds. However, space is a vacuum, meaning that it is devoid of matter, there are no gases or air there. Sound can’t travel in a vacuum, as sound vibrations don’t work, therefore we shouldn’t be able to hear any sound.

star wars

8. The Good Dinosaur

In the good dinosaur, a young dinosaur by the name of Arlo befriends a human boy. Arlo is an Apatosaurus which lived around 151 million years ago. Human beings as we are or Homo sapiens only evolved between 200,000 to 100,000 years ago so in reality Arlo and his friend would have missed each other by quite a few million years.

tgd_seven

9. Finding Dory

When searching for Dory’s family in Finding Dory, we discover that Dory was born in captivity, in an aquarium. However, Dory is a species of fish known as the Blue Tang. This species can’t be bred in captivity and have to be caught from their wild home of coral reefs in the Indo-Pacific Sea.

dory

 

disney