Many people take their ability to media-multitask as a point of pride.
Multitasking means the use of multiple media simultaneously … such as watching TV while surfing the Web.
According to a Pew Research Center survey, this behavior is increasingly common, especially among younger people (Brenner J 2013).
But the rather startling results of a new brain scan study suggest that media multitasking may actually harm your brain.
They show that simultaneously using mobile phones, laptops, and other devices may change the structure of your brain … and not for the better.
And the outcomes may help explain earlier studies linking habitual multitasking to poor attention control, depression, and anxiety.
Brain scans reveal gray-matter losses in media multitaskers
The study comes from a team led by Drs. Kep Kee Loh and Ryota Kanai at Britain's University of Sussex.
The researchers used functional magnetic resonance imaging (fMRI) scans to look at the brain structures of 75 adults, in real time.
First, the participants answered a questionnaire regarding their use of media devices: mobile phones, computers, television, and more.
The team then performed the fMRI scans, and compared the pictures of heavy multitaskers – those who routinely used multiple devices simultaneously – to people who typically used only one at a time.
change brain structure
Scientists have previously found that brain structure can change in response to prolonged exposure to new environments, behaviors, emotions, and experiences.
Our neural pathways and synapses can change at the cellular level (in the case of learning and memory) or when a damaged brain region “re-maps” to an intact region.
Other studies have shown that training – such as learning to juggle, or taxi drivers learning the map of London – can increase gray-matter densities in certain parts of the brain.
Compared to people who typically just used one device, heavy multitaskers had less-dense gray matter in a part of the brain critical to cognitive (thinking) and emotion-control functions.
These findings held true after the authors adjusted the results to account for individual traits known to affect gray matter in this region, called the anterior cingulate cortex (ACC).
Likewise, people diagnosed with Internet addiction – pathological overuse of the Internet or computers – have less-dense gray (and white) matter in the ACC region.
As the authors noted, this could explain the negative emotions and weaker cognitive control associated with habitual media-multitasking.
However, the scientists stressed the need for long-term studies to confirm whether habitual multitasking leads to brain structure changes, or whether people with less-dense gray matter are more attracted to media multitasking.
As Dr. Loh said, “Media multitasking is becoming more prevalent in our lives today and there is increasing concern about its impacts on our cognition and social-emotional well-being.”
2013 study yielded different results … but still disturbing
Last year, scientists from Japan's Tohoku University put students though four weeks of multitasking to test its brain effects.
They wanted to see whether and how multitasking might change the gray matter in various brain regions, and whether multitasking affected “functional connectivity”.
After one month, multitasking training was associated with two good things: increased gray matter in some brain regions, and increased “plasticity” in regions and networks that play roles in multitasking and other advanced cognitive functions.
However, multitasking degraded “functional connectivity” among these same brain regions and networks … a troubling finding, given increasing evidence that such connectivity is key to brain health.
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