Naturally, this normally happens on more than one synapse -- whole new networks can arise if they were active in this precise constellation enough times (and this how we think memories are formed, by the way). So kiss your SO while listening to Lou Vega often enough and soon just hearing “Mambo number five” will put you in a romantic mood. Donald Hebb, Canadian neuropsychologist, coined the phrase “What fires together, wires together” to describe this process. At first, these connections are fragile, but if you activate them enough times, eventually they’ll become hard-wired (and just as inseparable as Britney and Justin in ‘99). The counterpart to it, LTD, is triggered by another pattern of stimulation and is thought to weaken the connections you don’t need -- forgetting your ex’s name or refining new dancing steps. Synaptic plasticity is the concept behind what the cognitive-behavioural therapists want their patients to do: To change the rigid thought patterns and, step by step, establish new pathways by practicing, practicing and practicing. These pathways progress from being country roads to fully developed highways (transporting healthy behaviour) while the dysfunctional circuits slowly fall into oblivion.

Plasticity on a bigger scale manifests itself in different ways. A growing body of research shows that the more you use a specific muscle the more territory the brain dedicates to it. For instance, there is a study showing that while our finger movement areas are generally of a relatively similar size it doesn’t necessarily need to stay this way. After five days of practicing a piano exercise certain substantial changes in the participants’ motor cortex were found. The motor areas responsible for the fingers have expanded and took over parts of the neighbouring areas just like weeds spreading over your garden. The researchers thought big and went one step further: They also showed that the mere act of thinking about practicing this exercise had a similar effect! Mental practice seems to be as efficient in reorganising the brain structure as the physical one. Another example (which neuroscience students have probably heard more often than the Bible Belt children heard about Jesus) is the London taxi drivers. Experienced cabbies who have to memorise the map of the capital including tens of thousands of streets and dozens of landmarks has been shown to have a bigger posterior hippocampus, the brain structure processing spatial memory and orientation. The control group, the bus drivers, whose routes are predetermined and well-established, on the other hand, were stuck with their original hippocampus size. To counter the inevitable comments regarding “correlation does not equal causation” (meaning what if bigger hippocampi and thus better navigation skills led the cabbies to choose this job?) the researchers showed that the volume increase of the posterior hippocampus was positively correlated with the time spent as a driver. The longer you drive the more you brain adapts to it.