Autumn rain: being damp is inferred rather than truly felt. Photo: Getty
Show Hide image

On our nerves: what makes us itch or feel wet?

Michael Brooks’s science column. 

We’re all going to feel some unwanted damp on the skin over the next few weeks – welcome to autumn. But for those who feel wet due to a medical condition rather than the weather, researchers at Loughborough University have made what might just prove to be a welcome breakthrough.

It starts with a seemingly innocuous question: what makes wet stuff feel wet? By the end of this exploration, we will have encountered Joni Mitchell, patients with multiple sclerosis (MS) and a host of people suffering in ways that evoke Dante’s Inferno.

To some animal species, wetness is so critical to survival that evolution has equipped them to determine their state of external hydration: insects have humidity sensors. Human beings, however, don’t have wetness sensors on their skin, so understanding how we differentiate the sense of wetness from other sensations is a puzzle.

We have found clues in some of the tricks one can play on our species. The Loughborough researchers have shown that if you reduce the skin’s temperature using a dry cooling method, people feel as though their skin is wet. If you put something wet in contact with the skin, but at a temperature warmer than it, people don’t perceive it as wet.

So, clearly, we don’t feel wetness, we infer it. Our skin has an array of sensors for temperature and pressure, and it is a combination of these senses which tells us that something we are touching is wet. To find out what that combination might be, the Loughborough team experimented on 13 students, blocking and releasing their nerve sensitivities.

It turns out that crucial to wetness perception are nerves known as A-nerve fibres. Block the blood supply to these – using something like a blood-pressure cuff – and you become far worse at sensing wetness. Unsurprisingly, it is easier to sense cold wetness than warm wetness. The interplay of these different sensitivities enabled the researchers to create a model for the brain’s interpretation of wetness; in essence, it applies a weighting to each set of inputs in order to come to a probability-based conclusion on the body’s state.

This is more than an academic discovery because skin sensitivity is a serious medical issue. People suffering with MS frequently report an unpleasant feeling of cold wetness on their skin. It is a couple of short steps from feeling cold wetness to pain. One side effect of diabetes, for instance, can be dysaesthesia, when diabetics experience a burning or stabbing sensation on their skin, or feel the slightest touch from clothing or bedlinen as excruciating pain. In other cases, some diabetics can’t feel heat or touch sensitively enough to avoid injuring themselves.

It’s not just about the side effects of recognised diseases, though. There are various medical conditions associated with nerves sending pain signals in response to (apparently) nothing. Sufferers of central pain syndrome can report sensations such as being torn apart with hot knives, or being burned alive. No wonder it gets referred to as a Dante-type condition. Another oddity is Morgellons Disease. Joni Mitchell is perhaps the best-known sufferer of this unstoppable itching, which feels as if something is crawling under the skin. The medical orthodoxy is that the condition is indicative of a psychiatric disorder. However, if we knew more precisely what our skin’s nerve endings transmit to the brain, we might be able to help sufferers, delusional or not. 

Michael Brooks holds a PhD in quantum physics. He writes a weekly science column for the New Statesman, and his most recent book is At the Edge of Uncertainty: 11 Discoveries Taking Science by Surprise.

This article first appeared in the 08 October 2014 issue of the New Statesman, Grayson Perry guest edit

Getty
Show Hide image

Marcus Hutchins: What we know so far about the arrest of the hero hacker

The 23-year old who stopped the WannaCry malware which attacked the NHS has been arrested in the US. 

In May, Marcus Hutchins - who goes by the online name Malware Tech - became a national hero after "accidentally" discovering a way to stop the WannaCry virus that had paralysed parts of the NHS.

Now, the 23-year-old darling of cyber security is facing charges of cyber crime following a bizarre turn of events that have left many baffled. So what do we know about his indictment?

Arrest

Hutchins, from Ilfracombe in Devon, was reportedly arrested by the FBI in Las Vegas on Wednesday before travelling back from cyber security conferences Black Hat and Def Con.

He is now due to appear in court in Las Vegas later today after being accused of involvement with a piece of malware used to access people's bank accounts.

"Marcus Hutchins... a citizen and resident of the United Kingdom, was arrested in the United States on 2 August, 2017, in Las Vegas, Nevada, after a grand jury in the Eastern District of Wisconsin returned a six-count indictment against Hutchins for his role in creating and distributing the Kronos banking Trojan," said the US Department of Justice.

"The charges against Hutchins, and for which he was arrested, relate to alleged conduct that occurred between in or around July 2014 and July 2015."

His court appearance comes after he was arraigned in Las Vegas yesterday. He made no statement beyond a series of one-word answers to basic questions from the judge, the Guardian reports. A public defender said Hutchins had no criminal history and had previously cooperated with federal authorities. 

The malware

Kronos, a so-called Trojan, is a kind of malware that disguises itself as legitimate software while harvesting unsuspecting victims' online banking login details and other financial data.

It emerged in July 2014 on a Russian underground forum, where it was advertised for $7,000 (£5,330), a relatively high figure at the time, according to the BBC.

Shortly after it made the news, a video demonstrating the malware was posted to YouTube allegedly by Hutchins' co-defendant, who has not been named. Hutchins later tweeted: "Anyone got a kronos sample."

His mum, Janet Hutchins, told the Press Association it is "hugely unlikely" he was involved because he spent "enormous amounts of time" fighting attacks.

Research?

Meanwhile Ryan Kalember, a security researcher from Proofpoint, told the Guardian that the actions of researchers investigating malware may sometimes look criminal.

“This could very easily be the FBI mistaking legitimate research activity with being in control of Kronos infrastructure," said Kalember. "Lots of researchers like to log in to crimeware tools and interfaces and play around.”

The indictment alleges that Hutchins created and sold Kronos on internet forums including the AlphaBay dark web market, which was shut down last month.

"Sometimes you have to at least pretend to be selling something interesting to get people to trust you,” added Kalember. “It’s not an uncommon thing for researchers to do and I don’t know if the FBI could tell the difference.”

It's a sentiment echoed by US cyber-attorney Tor Ekeland, who told Radio 4's Today Programme: "I can think of a number of examples of legitimate software that would potentially be a felony under this theory of prosecution."

Hutchins could face 40 years in jail if found guilty, Ekelend said, but he added that no victims had been named.

This article also appears on NS Tech, a new division of the New Statesman focusing on the intersection of technology and politics.

Oscar Williams is editor of the NewStatesman's sister site NSTech.