Complex learning dismantles barriers in the brain

By learning a complex task over an extended period of time, each of us has the power to break down barriers in our brains once thought to be permanent.

Biology lessons teach us that the brain is divided into separate areas, each processing information from a specific sense. But new findings published in the journal eLife show we can supercharge our brain to be more flexible.

Scientists at the Jagiellonian University in Poland taught Braille to sighted individuals and found that learning such a complex and tactile task activated their visual cortex, when it was expected to only activate their tactile sense brain region.

"The textbooks tell us that the visual cortex processes visual tasks while the tactile cortex, called the somatosensory cortex, processes tasks related to touch.

"Our findings tear up that view, showing we can establish new connections if we undertake a complex enough task and are given long enough to learn it."

Marcin Szwed PhD, Project Leader, Department of Psychology, Jagiellonian University, Kraków, Poland, and lead author.

The findings could have implications for our power to influence sections of the brain by learning demanding skills, such as playing a musical instrument or learning to drive. Flexibility occurs as the brain overcomes normal divisions of labour and establishes new connections to boost its power.

It was already known that the brain can reorganize after a massive injury or as the result of massive sensory deprivation such as blindness. The visual cortex when deprived of input, adapts to other tasks such as speech, memory, and reading Braille by touch. Speculation existed this might also be possible in the normal, adult brain, but without conclusive evidence.

"For the first time we've shown that large-scale reorganization is a viable mechanism the sighted, adult brain is able to recruit when sufficiently challenged."

Marcin Szwed PhD

Over nine months, 29 volunteers were taught to read Braille while blindfolded. They achieved reading speeds of between 0 and 17 words per minute. Before and after the course, they took part in a functional Magnetic Resonance Imaging (fMRI) experiment measuring the impact of their learning on regions in their brains. This revealed that areas of their visual cortex, particularly the Visual Word Form Area, was activated following the course and with new connections to their tactile cortex being established.

In another experiment using transcranial magnetic stimulation, scientists applied a magnetic coil to selectively suppress the Visual Word Form Area in the brains of nine volunteers. This impaired those volunteers ability to read Braille, confirming the role of this brain area for that task. These results refute the idea that the visual cortex of the volunteers was used to picture Braille dots.

"We are all capable of retraining our brains if we're prepared to put in the work. The extra flexibility that we have uncovered might be one those features that make us human, and allows us to create a sophisticated culture, with pianos — and a Braille alphabet."

Marcin Szwed PhD

Szwed believes the findings call for a reassessment of our view of the functional organization of the human brain, which is much more flexible than the brains of other primates.

Abstract
The brain is capable of large-scale reorganization in blindness or after massive injury. Such reorganization crosses the division into separate sensory cortices (visual, somatosensory...). As its result, the visual cortex of the blind becomes active during tactile Braille reading. Although the possibility of such reorganization in the normal, adult brain has been raised, definitive evidence has been lacking. Here, we demonstrate such extensive reorganization in normal, sighted adults who learned Braille while their brain activity was investigated with fMRI and transcranial magnetic stimulation (TMS). Subjects showed enhanced activity for tactile reading in the visual cortex, including the visual word form area (VWFA) that was modulated by their Braille reading speed and strengthened resting-state connectivity between visual and somatosensory cortices. Moreover, TMS disruption of VWFA activity decreased their tactile reading accuracy. Our results indicate that large-scale reorganization is a viable mechanism recruited when learning complex skills.

About eLife
eLife is a unique collaboration between the funders and practitioners of research to improve the way important research is selected, presented, and shared. eLife publishes outstanding works across the life sciences and biomedicine -- from basic biological research to applied, translational, and clinical studies. All papers are selected by active scientists in the research community. Decisions and responses are agreed by the reviewers and consolidated by the Reviewing Editor into a single, clear set of instructions for authors, removing the need for laborious cycles of revision and allowing authors to publish their findings quickly. eLife is supported by the Howard Hughes Medical Institute, the Max Planck Society, and the Wellcome Trust. Learn more at elifesciences.org.

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