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Better Grip with Wrinkly Fingers? MDC-Researchers find no Proof

When we swim or bathe for too long our fingertips get wrinkled. Wrinkling is an involuntary response controlled by the body’s autonomic nervous system. Tiny blood vessels in the skin constrict after water exposure and so does the skin of the fingertips. What are wrinkled fingers good for? Researchers have been pursuing this question for quite some time as did Julia Haseleu and Damir Omerbašić from Professor Gary R. Lewin’s research group at the Max Delbrück Center for Molecular Medicine (MDC) Berlin-Buch. One theory, proposed in a recent study which received a lot of press coverage, suggested that wrinkled fingers help humans get a better grip of wet objects perhaps by enhancing touch sensitivity. The MDC researchers tested this idea again, but found that wrinkled fingers are of no advantage to get a better grip of wet or dry objects. And they have no influence on touch sensitivity (PLOS ONE, doi http://dx.plos.org/10.1371/journal.pone.0084949)*.

For their study the neuroscientists had asked 40 volunteers – mostly undergraduate and graduate students – to participate. To begin with, the participants had to bathe both hands in warm water (40 ºC) for half an hour to induce fingertip wrinkling. The subjects were then asked to transfer 52 dry or wet objects – glass marbles, rubber balls, plastic dice and brass weights – from one container to another via a small 5 cm diameter hole in walled partition. The subjects repeated the task with dry, unwrinkled fingertips.

It turned out the wrinkled fingers offered no advantage over nonwrinkled fingers. In both experiments dexterity was the same and there was no influence on touch sensitivity. Although they used exactly the same experimental design, the MDC researchers could not reproduce the result that wrinkling was good for dexterity that was published by neurobiologists from the University of Newcastle, United Kingdom, which received a lot of attention in the media at the beginning of 2013.

 What are wrinkled fingers good for? Julia Haseleu: “It is quite questionable, if they are of any advantage at all. It could well be that wrinkled fingers happen after skin blood vessels constrict, and that is it.”

*Water-induced finger wrinkles do not affect touch acuity or dexterity in handling wet objects

Julia Haseleu1*, Damir Omerbašić1*, Henning Frenzel1,Manfred Gross2and Gary R Lewin1

1 Department of Neuroscience, Max Delbrück Center for Molecular Medicine, Berlin-Buch, Germany

2 Department of Audiology and Phoniatrics, CharitéUniversitätsmedizin, Berlin, Germany

* These authors contributed equally

Better grip with wrinkly fingers? – MDC-researchers find no proof. (Photo/ Copyright: Julia Haseleu)

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