The science of cutaneous perception

How experts use touch differently

A few years ago, five researchers in the Netherlands wanted to better understand what characteristics might distinguish an expert in sailing.

They recruited six professional sailers and a collection of intermediate and non-sailers. A real dinghy was brought into the lab and placed in the center of an octagonal room with fans positioned at each of the eight corners. The subjects were all given noise-canceling earphones and told they had to keep their eyes closed the entire time, removing the two most obvious sensory receptors. Then they had to “sail,” or navigate the boat along a sailing simulation.

The fans clicked on and off at different intensities and different intervals to produce the effect of changing wind speeds and directions, approximating real sailing conditions on the water.

When the fans were at their highest speed, all three subject groups were able to accurately and consistently recognize the directions of the wind blowing.

Where the professional sailers distinguished themselves is when the wind speeds were at their lowest. Far better than novices or intermediates, they could perceive the most subtle shifts in wind direction. When everyone else was in the dark, the experts used their other senses to expand their performance.

The researchers called this expertise in “cutaneous perception.” They likened it to studies on blind people that perform better in tactile discrimination tasks than sighted humans. Findings there have shown that blind people don’t “touch better” because they’re blind. They touch better because they use their sense of touch more often. It is a reward of their experience, not their disability.

In The Atlantic this week, I wrote about a 2017 study led by biomechanics expert Glenn Fleisig into the finger forces imparted on a baseball by expert pitchers. Fleisig et al. found that the last peak of force from the fingers occurs only milliseconds before the ball is released, and that peak averaged 185 Newtons of force. This, as I wrote, is enough force to heave a bowling ball 90 mph.

What Fleisig told me is that previous studies on the biomechanics of pitching never could fully decipher how pitchers throw so hard. The angular velocity of the shoulder maxes out around 90 mph. Legs and torque add some heft, but it seems the fingertips were doing a lot more for pitching than we’d known.

Fleisig found that differences in those finger forces impacted the ball’s spin, ball flight, and velocity. You hear often about pitchers late in games battling a tired arm. Perhaps they could mitigate late-inning arm fatigue with more concentration on the fingers.

The other question I think some teams should be asking is: Who is using their cutaneous perception better?

Tactile clarity

I began thinking about this thanks to my own failings as an athlete. When I played basketball growing up, I was a decent spot-up shooter. Where I struggled the most was dribbling.

I marveled at other players who could yo-yo the ball through their legs without looking or breaking stride. I’ve since come to appreciate that the ability to “feel” in dribbling is, like the sailers who can decipher subtle wind shifts, a function of experience and a lot of deliberate practice.

But is that it?

As a matter of fact, there are differences in “tactile clarity” between people. People with smaller hands, in general, test better, which helps to explain why women typically have sharper tactile clarity than men — and may help to explain why big men like Shaq more often struggle with a fine-motor task like the delicate release on a free throw.

Do we know this for sure? No. As far as I know, it’s not being tested, even though hand sizes are measured in NBA and NFL scouting combines.

Like other senses, tactile clarity also peaks at a young age and gets worse as we age. But unlike vision or hearing, there are no contact lenses or hearing aids for the skin. We don’t have any baseline (like 20/20 vision) for what good tactile clarity should be, and we don’t have examples of superior “touching” ability to show us what’s possible, like perfurmers and sommeliers who have honed their noses and palettes to perform amazing things with their sense of smell and taste.

We can point to athletes, but generally we give credit to other things besides their sense of touch. It’s a blasphemous oversight.

A famous experiment by Roland Johansson in the 1980s offers the perfect example why. In the experiment, he asked a woman to strike a match, why she executes promptly.

He then places a tiny prick of analgesic onto the finger tips of her thumb, index, and middle fingers, numbing a few of the many thousands of sensory receptors in those regions. What happened is that the woman suddenly became unable to pick up the match or pinch it in her fingers. She fumbled for nearly a minute.

Nothing happened to her motor function. Just her tactile clarity was temporarily dulled, and it ruined her capacity for skilled movement.

You can watch the video here:

Shameless plug

You can read my story for The Atlantic for free here: A Touch Revolution Could Transform Pitching

And do follow Adam Moreau: https://x.com/FlexProGrip

Alex Fast: https://x.com/AlexFast8

Connor Lunn: https://x.com/ConnorLunn

And David Ginty: https://www.gintylab.hms.harvard.edu/

Links

Meditation can supercharge your endurance … What’s 80/20 training? … Does height matter in soccer? Yes … “Fourteen tripods circled the basket, all equipped with infrared cameras.” … Professional women’s baseball team set to launch in 2026 … Pickleball physics … NBA strikes Airbus deal for more comfortable planes to reduce athletes’ fatigue … The new science of chess … New pill mimics the effects of a 10K without moving a muscle

References

Kinoshita, Hiroshi, et al. "Finger forces in fastball baseball pitching." Human movement science 54 (2017): 172-181.

Pluijms, Joost P., et al. "Expertise effects in cutaneous wind perception." Attention, Perception, & Psychophysics 77 (2015): 2121-2133