studying the effect of distraction on language learning, researchers compared the effects of magnetic stimulation of a scalp location where stimulation can be quite uncomfortable, with another area where it is not at all uncomfortable.  

original article: Smalle et al., 2022 (Proceedings of the National Academy of Sciences of the United States of America), reported in: The Scientist by Catherine Offord on 4th April 2022

this story was in episode 28 #brain #stimulation #language #distraction

the error bar says

the scientist dot com reports - briefly - on a brain stimulation & artificial language study which claims that distracting people improves learning. in the paper, participants listened to a stream of seemingly-random words & syllables that combined into words, while they were watching the video Planet Earth with the sound off.

before listening to these novel sounds, the participants' heads were stimulated with a powerful electromagnet, 600 times in 30 seconds. the aim of this was to disrupt the cognitive mechanisms in the brain that normally prevent us from learning these random-sounding sounds. these cognitive mechanisms are thought to be in the prefrontal cortex - an important part of the brain involved in thinking.

the results are a little hard to wade through, but the headline finding is that brain stimulation, or cognitive distraction, makes you better at learning these new hidden word sounds. brain stimulation done on a different, also less distracting, brain area was used as a comparison.

is disruption good for language learning?


i struggled to follow the logic & the results a little bit - language is not really my topic. but brain stimulation is. so, let me just say this.

after 40 years of brain stimulation research it is, frankly weird, that scientists are still not using sensible control or comparison conditions. when the head is stimulated with an electromagnet, some locations on the scalp produce almost no sensations or muscle twitches; other locations produce strong contractions in the scalp, face, jaw or neck; some locations produce pain.

if you're stimulating a scalp location with some of these side-effects, it would be basic scientific good practice to choose a control or comparison location that had a similar level of twitchiness, pain & distraction. especially if your study is *about* distraction.

it is a puzzle, then, that some researchers still use the top of the head - the so-called vertex - as a control location when that spot is among the least-annoying locations, as a comparison for the prefrontal cortex, which is one of the more annoying locations.

in a second error, the authors of this study referred to a paper in support of the particular kind of brain stimulation that they used. but this cited paper did not use what they said it did, nor did they find the results that the authors said they found.


details, people, details.


The Scientist: fair - scientific story mostly intact