I think we all knew this, but recent studies have now shown direct correlation between iPhone use (or smartphone, etc.) and decreased attention span. For some students in my classes this has become a problem. For our school it is an epidemic.
On the one hand , the electromagnetic waves produced by browsing online enact alpha waves at cycles of 8-12 Hrz, the wave cycle when the brain is inattentive or wandering. The term is "cortical idling." Same as television of course, but worse. A pleasurable, relaxed nearly hypnotic state - but one in which the brain's attention/focus is pretty much gone. Any possibility for "learning" drops out. (Even if learning is more than information recall, which it is, learning is still not happening.)
On the other hand we now also know about the small hits of dopamine released as the brain goes out seeking novelty and getting it immediately while one browses online. Dopamine is one of the most addictive substances on the planet, as it is involved with the seeking and reward system of our brain which we must use in order to survive. We must learn what is pleasurable in order to seek it out and obtain it. Dopamine reinforces that seek and reward behavior.
Smartphones capitalize on those small releases of dopamine during browsing (as observed in lab tests) but also during interactions such as "liking" or being retweeted on social media. The brain very quickly becomes addicted to these dopamine hits and the stimulation and immediate gratification associated with them. Soon the brain associates the device with dopamine and habitually and unconsciously one will reach for it expecting pleasure. As one then browses or interacts with social media, dopamine is released and the reward satisfied.
The danger is just how suggestive smartphone use actually can be. For example, dopamine is also associated with impulse control (as seen in methamphetamine addicts), as well as with emotional control and the ability to experience certain emotions. Dopamine (or addiction to it) directy affects emotions such as empathy.
Researchers are now looking into how smartphones (or here in this study daily internet use or the use of smartphones) have affected IQ and basic learning skills, in addition to affecting emotional and social intelligence (skills such as problem solving, but also basic reading and writing).
While stimulants release or act on dopamine to increase focus in children or adults with attention deficit disorder, here the brain is set to inattentive alpha wave mode first only to have its momentary bursts of attention from within lengthier cycles of inattention rewarded. And so attention becomes a fragmentary novelty-seeking pleasure mechanism, rather than a mechanism of focus which helps true, deep learning occur.
More info at the link below: