How simply looking at pictures can make you feel itchy, cold, tired or dizzy: If you don't believe us try staring at these

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Just looking at pictures of striped objects such as zebras or deckchairs can trigger migraines and epileptic seizures in sensitive people, it was reported last week.

Researchers at the University Medical Centre Utrecht in the Netherlands suggest that the sharp contrast between stripes causes overactivity in the brain that triggers the symptoms.

But this isn’t the only type of picture that can cause a physical reaction in the body — as these images show.

Ouch! we feel others' pain 

Most of us feel sad if we see someone in pain, but in a 2009 study at the University of Birmingham 29 per cent of people felt physical symptoms such as tingling, stabbing, throbbing or aching in the same place the one in the image was hurt.

The study’s author psychologist, Dr Stuart Derbyshire, says that several possible explanations include the idea that in �almost everyone, when observing another person’s injury, we activated the emotional areas of the brain, and if this emotional activity is intense enough, it can drive activity in sensory areas that lead to pain’.

Don't peek at this if you're breastfeeding

Breastfeeding women can find their breasts leak milk when they look at a picture of a newborn.

�For most women it would need to be a picture of their baby, but it can be stimulated by an image of any baby,’ says independent antenatal educator Bridget Supple.

The reaction, known as let-down response, occurs because the sight of the infant triggers the release of the bonding hormone oxytocin from the brain — the same hormone that releases milk for breastfeeding.

Supple says applying gentle pressure on the breasts, such as crossing your arms across your chest, can stop it.

Phantom allergies

Just seeing a picture of an allergen — such as dust, pollen or cat fur — has been shown to trigger asthma symptoms in people whose attacks are caused by allergies.

In a trial published in the Journal of Asthma in 2012, 19 asthmatics were asked to view 30 pictures depicting common allergens, then 30 pictures of neutral images such as faces.

They didn’t know what was being tested, but were asked to report any allergy symptoms such as wheezing or tightness in the chest. Symptoms increased by 15 per cent when they were shown the �allergic’ pictures, but nothing happened with neutral ones. The researchers suggested asthma patients learn to expect symptoms when they see something they are allergic to — and in this case their body made that happen.

Scratching's so catching!

An image of someone scratching, or of fingernail marks on the skin, or of something that triggers an itch, for instance head lice, can prime our body to notice the �itchy’ signals that happen all the time on our skin but that the brain would mostly ignore.

This stimulus makes you likely to scratch, too.

And it’s not just psychological: U.S. scientists from Washington University School of Medicine in St Louis recently discovered that the sight of someone else scratching actually causes the release of a chemical in the brain that communicates itch signals from the skin to the spinal cord.

Where you scratch in response to an image depends on the health of your own skin — people with skin conditions such as dermatitis scratch in different places from the person they’re watching, while those with healthy skin scratch in the same place as that person.

Are you feeling giddy?

This type of picture can trigger feelings of dizziness or a swimming head in people who are afraid of heights.

�With any fear, we are hyper-vigilant to it and magnify the response as a type of survival mechanism — this can cause physical symptoms,’ says physiotherapist Steven Hodgson, from the Sheffield Vertigo and Balance Centre.

Pictures of complicated patterns such as zigzags or herringbone check can also cause dizziness in those whose balance is compromised by a problem such as an inner ear infection, or an ear disorder such as Meniere’s disease.

When we struggle with balance, we rely more heavily on information from the eyes to determine our position in a space, but busy patterns overload the brain.

We all join in a yawn - because it's cool

Yawning is also emotionally catching and 40-50 per cent of us yawn when seeing an image of someone else doing so.

�A growing body of literature shows that yawning cools the brain, which stimulates arousal, and the spreading of this behaviour could promote collective vigilance in a group,’ says psychologist Professor Andrew Gallup, an expert on contagious yawning based at the State University of New York at Oneonta.

Keeping everyone awake at the same time would have been useful when hunting in tribes.

Brr! pass me my jumper

If you’re feeling the need to get a jumper right now, you’re experiencing what scientists at the University of Sussex recently named �temperature contagion’.

Neuroscientist Dr Neil Harrison found that when people looked at pictures of others holding their hand in ice water, their own body temperature fell slightly. This is possibly �because much of human success comes from our ability to work together in complex communities — this would be hard to do it we were not able to rapidly empathise with each other to predict another’s thoughts, feeling and motivations’, he told Good Health.

Exactly how that ends up as a drop in your own body temperature is not clear — �but higher brain areas like the cortex can regulate the temperature to some degree and we believe that’s what’s at work here,’ he says.

Warmth doesn’t seem to be as catching, according to Dr Harrison’s research.

Keep calm and watch a tree

Do YOU feel calmer gazing at all that greenery?

Possibly that’s because your heart rate is slowing.

Studies have shown that spending time in nature can lower heart rate and also raise activity in the para- sympathetic nervous system which calms the body — and you get similar effects looking at pictures of plants.

In a study that was published in 2012, researchers at VU University in Amsterdam found that people in hospital waiting rooms with pictures of nature on the walls felt less anxious than those in rooms that were bare.

Researchers in South Korea’s Chungnam National University have also found that looking out of windows and seeing trees improves mental health.

One theory is that the greenness causes a reaction in the brain that lowers activity in areas controlling fear, such as the amygdala.

This allows the system that calms us to take over.

Crumpets mean a hole lot of anguish

When some people look at pictures of things with holes, such as the end of a watering can or lotus seed plants, it triggers a feeling of unease or anxiety. Others get tingles down their spine; a few even start to feel physically sick.

This is known as trypophobia, or fear of holes. It’s thought as many as 10 per cent of the population feels unease seeing such pictures.

�We’re not sure why it occurs, but these type of images can’t be easily processed by the brain,’ explains psychologist Arnold Wilkins, professor emeritus at the University of Essex.

He adds that the holes may also �share the spatial characteristics of the markings of dangerous animals like certain poisonous snakes or frogs, so it might be that we see them as threatening or disgusting as an evolutionary hangover’.