Menus Subscribe Search

Follow us


Quick Studies

touch.jpg

(Photo: Tela Chhe/flickr)

The Mystery of Human Touch

• April 07, 2014 • 10:25 AM

(Photo: Tela Chhe/flickr)

Scientists are learning more about how we process feelings of gentle touch. New discoveries published Sunday could help restore fading sensations—and ease painful hypersensitivity.

There’s a fine line between pleasure and pain—and, in some people, it is cruelly drawn.

The normally gentle pressure of a cotton shirt, or what should be the arousing caress of a lover’s tongue, can be painful for tactile allodynia patients.

Two papers published by Nature (here and here) cast new light on how we experience the flutters and pressures of gentle touch. The discoveries could help lead to respite from the unending pain of tactile allodynia. They could also help to restore fading senses of touch for diabetes sufferers, cancer patients undergoing chemo—and for everybody else as they age.

New discoveries could help to restore fading senses of touch for diabetes sufferers, cancer patients undergoing chemo—and for everybody else as they age.

When our skin rubs up against an object, our brain quickly paints a mental picture of it. We get a clear sense of the shape and texture of whatever it is that we’re turning over in our hand, or that’s stroking unwelcomely against us in a crowded bar.

Merkel cells are critical to these feelings. They’re found at the bottom layer of mammals’ skin, where they act as information conveyor belts, feeding data from skin cells into our central nervous systems.

But it’s long been a mystery how Merkel cells actually work. Do they resemble nerve cells—which actively encode and pass along information as subtle electrical pulses? Or do they mimic some of the cells in our inner ears—which act as tiny amplifiers, enhancing sound information gleaned from the vibrations of tiny hairs?

Scientists subjected mice and their Merkel cells to tests. Mice were bred to produce fluorescing proteins involved in the functioning of Merkel cells for some of the experiments; other mice lacked genes needed to produce those proteins at all. The results led scientists to conclude that the way these cells work isn’t an “either/or” proposition—it’s an “and” scenario.

It turns out that Merkel cells actively encode basic information about pressure that’s being exerted when we touch something. And they also amplify and enhance subtler sensations—such as the shape of a keyboard beneath fingertips.

“[T]he Merkel cell–neurite complex is a compound sensory system with two receptor cell types that mediate different aspects of touch,” the scientists write in one of the papers, both of which were posted online Sunday ahead of print publication. “This provides the first direct evidence that Merkel cells are not simply passive mechanical filters in the skin.”

The findings reveal that the cells are special, but their dual systems are not entirely unique. A similar division of labor exists in our retinas, where rods help us see basic details in low light, while cones paint our surroundings in sharp and colorful detail.

Ellen Lumpkin, an associate professor at Columbia University and a co-author of both papers, says that “understanding the basis of gentle touch has implications for unrelieved pain, particularly tactile allodynia”—which she calls a “common and debilitating” condition.

The discovery also pushes forward science’s understanding of touch, which is sorely lacking when compared with its knowledge of vision, smell, taste, and hearing.

John Upton
John Upton is a science journalist with an ecology background. He has written recently for VICE, Slate, Nautilus, Modern Farmer, Grist, and Audubon magazine. He blogs at Wonk on the Wildlife. Upton's favorite eukaryotes are fungi, but he won't fault you for being human. Follow him on Twitter @johnupton.

More From John Upton

A weekly roundup of the best of Pacific Standard and PSmag.com, delivered straight to your inbox.

Recent Posts

October 31 • 4:00 PM

Should the Victims of the War on Drugs Receive Reparations?

A drug war Truth and Reconciliation Commission along the lines of post-apartheid South Africa is a radical idea proposed by the Green Party. Substance.com asks their candidates for New York State’s gubernatorial election to tell us more.


October 31 • 2:00 PM

India’s Struggle to Get Reliable Power to Hundreds of Millions of People

India’s new Prime Minister Narendra Modi is known as a “big thinker” when it comes to energy. But in his country’s case, could thinking big be a huge mistake?


October 31 • 12:00 PM

In the Picture: SNAP Food Benefits, Birthday Cake, and Walmart

In every issue, we fix our gaze on an everyday photograph and chase down facts about details in the frame.


October 31 • 10:15 AM

Levels of Depression Could Be Evaluated Through Measurements of Acoustic Speech

Engineers find tell-tale signs in speech patterns of the depressed.


October 31 • 8:00 AM

Who Wants a Cute Congressman?

You probably do—even if you won’t admit it. In politics, looks aren’t everything, but they’re definitely something.


October 31 • 7:00 AM

Why Scientists Make Promises They Can’t Keep

A research proposal that is totally upfront about the uncertainty of the scientific process and its potential benefits might never pass governmental muster.


October 31 • 6:12 AM

The Psychology of a Horror Movie Fan

Scientists have tried to figure out the appeal of axe murderers and creepy dolls, but it mostly remains a spooky mystery.


October 31 • 4:00 AM

The Power of Third Person Plural on Support for Public Policies

Researchers find citizens react differently to policy proposals when they’re framed as impacting “people,” as opposed to “you.”


October 30 • 4:00 PM

I Should Have Told My High School Students About My Struggle With Drinking

As a teacher, my students confided in me about many harrowing aspects of their lives. I never crossed the line and shared my biggest problem with them—but now I wish I had.


October 30 • 2:00 PM

How Dark Money Got a Mining Company Everything It Wanted

An accidentally released court filing reveals how one company secretly gave money to a non-profit that helped get favorable mining legislation passed.


October 30 • 12:00 PM

The Halloween Industrial Complex

The scariest thing about Halloween might be just how seriously we take it. For this week’s holiday, Americans of all ages will spend more than $5 billion on disposable costumes and bite-size candy.


October 30 • 10:00 AM

Sky’s the Limit: The Case for Selling Air Rights

Lower taxes and debt, increased revenue for the city, and a much better use of space in already dense environments: Selling air rights and encouraging upward growth seem like no-brainers, but NIMBY resistance and philosophical barriers remain.


October 30 • 9:00 AM

Cycles of Fear and Bias in the Criminal Justice System

Exploring the psychological roots of racial disparity in U.S. prisons.


October 30 • 8:00 AM

How Do You Make a Living, Email Newsletter Writer?

Noah Davis talks to Wait But Why writer Tim Urban about the newsletter concept, the research process, and escaping “money-flushing toilet” status.



October 30 • 6:00 AM

Dreamers of the Carbon-Free Dream

Can California go full-renewable?


October 30 • 5:08 AM

We’re Not So Great at Rejecting Each Other

And it’s probably something we should work on.


October 30 • 4:00 AM

He’s Definitely a Liberal—Just Check Out His Brain Scan

New research finds political ideology can be easily determined by examining how one’s brain reacts to disgusting images.


October 29 • 4:00 PM

Should We Prosecute Climate Change Protesters Who Break the Law?

A conversation with Bristol County, Massachusetts, District Attorney Sam Sutter, who dropped steep charges against two climate change protesters.


October 29 • 2:23 PM

Innovation Geography: The Beginning of the End for Silicon Valley

Will a lack of affordable housing hinder the growth of creative start-ups?


October 29 • 2:00 PM

Trapped in the Tobacco Debt Trap

A refinance of Niagara County, New York’s tobacco bonds was good news—but for investors, not taxpayers.


October 29 • 12:00 PM

Purity and Self-Mutilation in Thailand

During the nine-day Phuket Vegetarian Festival, a group of chosen ones known as the mah song torture themselves in order to redirect bad luck and misfortune away from their communities and ensure a year of prosperity.


October 29 • 10:00 AM

Can Proposition 47 Solve California’s Problem With Mass Incarceration?

Reducing penalties for low-level felonies could be the next step in rolling back draconian sentencing laws and addressing the criminal justice system’s long legacy of racism.


October 29 • 9:00 AM

Chronic Fatigue Syndrome and the Brain

Neuroscientists find less—but potentially stronger—white matter in the brains of patients with CFS.


October 29 • 8:00 AM

America’s Bathrooms Are a Total Failure

No matter which American bathroom is crowned in this year’s America’s Best Restroom contest, it will still have a host of terrible flaws.


Follow us


Levels of Depression Could Be Evaluated Through Measurements of Acoustic Speech

Engineers find tell-tale signs in speech patterns of the depressed.

We’re Not So Great at Rejecting Each Other

And it's probably something we should work on.

Chronic Fatigue Syndrome and the Brain

Neuroscientists find less—but potentially stronger—white matter in the brains of patients with CFS.

Incumbents, Pray for Rain

Come next Tuesday, rain could push voters toward safer, more predictable candidates.

Could Economics Benefit From Computer Science Thinking?

Computational complexity could offer new insight into old ideas in biology and, yes, even the dismal science.

The Big One

One town, Champlain, New York, was the source of nearly half the scams targeting small businesses in the United States last year. November/December 2014

Copyright © 2014 by Pacific Standard and The Miller-McCune Center for Research, Media, and Public Policy. All Rights Reserved.