Smartphone users have an enhanced thumb sensory
representation in the brain. The brain activity is
proportional to use accumulated over the previous 10
days. An episode of intense use is transiently
imprinted on the sensory representation and sensory
processing in the brain is adjusted on demand by
touchscreen phone use.
Cortical activity allotted to the tactile receptors
on fingertips conforms to skilful use of the hand.
For instance, in string instrument players, the
somatosensory cortical activity in response to touch
on the little fingertip is larger than that in
control subjects.
Such plasticity of the fingertip sensory
representation is not limited to extraordinary
skills and occurs in monkeys trained to repetitively
grasp and release a handle as well.
Touchscreen phones also require repetitive finger
movements, but whether and how the cortex conforms
to this is unknown.
By using electroencephalography (EEG), researchers
measured the cortical potentials in response to
mechanical touch on the thumb, index, and middle
fingertips of touchscreen phone users and nonusers (owning
only old-technology mobile phones).
Although the thumb interacted predominantly with the
screen, the potentials associated with the three
fingertips were enhanced in touchscreen users
compared to nonusers.
Within the touchscreen users, the cortical
potentials from the thumb and index fingertips were
directly proportional to the intensity of use
quantified with built-in battery logs. Remarkably,
the thumb tip was sensitive to the day-to-day
fluctuations in phone use: the shorter the time
elapsed from an episode of intense phone use, the
larger the cortical potential associated with it.
Researchers suggest that repetitive movements on the
smooth touchscreen reshaped sensory processing from
the hand and that the thumb representation was
updated daily depending on its use. They propose
that cortical sensory processing in the contemporary
brain is continuously shaped by the use of personal
digital technology.
For more information
Use-Dependent Cortical Processing from Fingertips in
Touchscreen Phone Users
MDN |