New Worlds: Human whisking
Blindfolded volunteers with "whiskers" artificially attached to their fingers were able to adopt new sensory input.
Human whiskers experiment. Photo: Courtesy Weizmann Institute
Some men may have moustaches, but only rodents can move their facial hairs to
locate objects in their environment.
Rats have this “whisking” ability,
and they are able to move their whiskers about eight times a second for “radar.”
Could humans acquire this sense? And if they can, what could understanding the
process of adapting to new sensory input tell us about how humans normally
Researchers at the Weizmann Institute investigated this by attaching
plastic “whiskers” to the fingers of blindfolded volunteers and asking them to
carry out a location task. The findings, which recently appeared in the Journal
of Neuroscience, have yielded new insight into the process of sensing, and they
may point to new avenues in developing aids for the blind.
team, including Drs. Avraham Saig and Goren Gordon, and Eldad Assa in the group
of Prof. Ehud Ahissar and Dr. Amos Arieli, all of the neurobiology
department, attached a “whisker” – a 30 centimeter- long elastic “hair” with
position and force sensors on its base – to the index finger of each hand of a
blindfolded subject. Then two poles were placed at arm’s distance on either side
and slightly to the front of the seated subject, with one a bit farther back
than the other. Using just their whiskers, the subjects were challenged to
figure out which pole – left or right – was the back one. As the experiment
continued, the displacement between front and back poles was reduced, up to the
point when the subject could no longer distinguish front from back.
the first day of the experiment, subjects picked up the new sense so well that
they could correctly identify a pole that was set back by only eight
An analysis of the data revealed that the subjects
accomplished this by moving their bewhiskered hands together. This allowed them
to feel which pole was the back one because the whisker on that hand made
On the second day of testing, the volunteers improved their
whisking skills significantly: The average sensory threshold went down to just 3
cm, with some being able to sense a displacement of just 1 cm.
findings reveal some new principles of active sensing and show us that
activating a new artificial sense in a ‘natural’ way can be very efficient,”
“Our vision for the future is to help blind people ‘see’ with their
fingers. Small devices that translate video to mechanical stimulation, based on
principles of active sensing that are common to vision and touch, could provide
an intuitive, easily used sensory aid.”
Interestingly, the ability of the
subjects to sense time differences had not changed over the two
Rather, they had improved in the motor aspects of their whisking
strategies: Slowing down their hand motions – in effect lengthening the delay
time – enabled them to sense a smaller spatial difference.
There are more women heads of political parties today than ever
before. But how do they sound? A study at Duke University and the University of
Miami found that people prefer leaders with more masculine voices, even in
feminine leadership roles.
Male and female leaders with masculine voices
are preferred by both men and women in the US. However, even in leadership roles
that are typically held by women, both sexes prefer women leaders with
low-pitched voices, according to research published recently in the open-access
journal PLOS ONE.
Drs. Rindy Anderson and Casey Klofstad said that
although earlier studies have shown that people prefer leaders with more
masculine voices, this research adds a caveat: What happens when the leadership
position is one that is typically held by women or perceived as more feminine,
such as being a school board member or president of a parent- teacher
In hypothetical elections for such positions, the researchers asked
people to listen to the phrase: “I urge you to vote for me this November” spoken
by two voices that differed only in pitch.
They found that both men and women
preferred female candidates with masculine voices. Men also preferred men with
masculine voices, but women did not discriminate between the male voices they
According to the authors, their results suggest that the influence of
voice pitch on perceptions of leadership capacity is consistent across different
domains of leadership and independent of social context.
explains, “We often do not consider how our biology can influence our decision
making. The results of this study show that voice pitch – a physiological
characteristic – can affect how we select our leaders.”