Plasticity of the human brain

The human brain is constantly changing. Whether it is responding to experiences, learning skills or recovering from injury, the function and structure of the brain are in a continual state of flux that scientists refer to as plasticity, which continues throughout life.

Most of our understanding of plasticity comes from studies on animal brains. With advances in non-invasive brain imaging, however, the human brain has become accessible for investigations into plasticity. For example, we have seen that the area of the brain involved in navigation is larger in London taxi drivers than in control subjects¹ and that learning to juggle can reshape areas of the brain involved in movement. There is also indirect evidence that neurons can regenerate, even in adult human brains².

IMAGING PLASTICITY

In the past few decades, various non- invasive brain-imaging methods have been used in studies on brain plasticity.

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Fig. 1 | Brain MRI scans Training-induced structural changes observed in top-view (left) and front-view (right)... [more]

Fig. 1 | Brain MRI scans Training-induced structural changes observed in top-view (left) and front-view (right) brain MRI scans. With improving motor performance during the learning of a balancing task, structural changes in the grey (cyan, green) and white matter (magenta, blue) in the prefrontal cortex and the supplementary motor areas occur. Interestingly, some of these structural changes are only transient while other seem to be permanently linked to improved function. (Adapted from ref. 11) [less]

<b>Fig. 1 | Brain MRI scans</b> Training-induced structural changes observed in top-view (left) and front-view (right) brain MRI scans. With improving motor performance during the learning of a balancing task, structural changes in the grey (cyan, green) and white matter (magenta, blue) in the prefrontal cortex and the supplementary motor areas occur. Interestingly, some of these structural changes are only transient while other seem to be permanently linked to improved function. (Adapted from ref. 11)

© Max Planck Institute for Human Cognitive and Brain Sciences

© Max Planck Institute for Human Cognitive and Brain Sciences

Structural imaging. Certain types of magnetic resonance imaging (MRI) can reveal the structure of grey matter³ and white matter⁴. These techniques allow scientists to probe neuronal density in various areas of the brain, to study the size and layout of connections linking regions, or to assess structural changes owing to learning (Fig. 1), injury or disease.

Functional MRI (fMRI). This technique logs changes in brain function by measuring changes in local blood flow or haemoglobin oxygenation (Fig. 2). fMRI can measure changes in the brain’s pattern of activity after injury or learning⁵.