A recent report came out stating that learning a language grows the brain . And indeed this does seem to be true. The report noted that in this particular study those that learned a language compared to a control group “grew” various parts of the brain. Interestingly they noted that the brains of those who learned easily or not developed slightly differently. Those who learned easily had greater growth in the hippocampus, an area deep in the brain which consolidates new learning and also spatial navigation. For those that had to invest more effort in learning it was an area called the middle frontal gyrus that grew most. So far so good but we’ve also seen that the famous London cabbies have an enlarged hippocampus , , that piano tuners have differently wired brains , that meditation can grow parts of the brain  and that Tetris can also grow the brain  as can dancing and playing music . So what is it that can grow your brain? The answer is surprising to some – anything you want. Yes, anything you want!
The brain is an organic continually changing chemical environment
The problem is not the brain growing but rather a misinterpretation of the brain. We seem to think it is static and that we have good brain or not. We are intelligent or not. We are skilled or not. This is not true. The brain is far from static – it is continually changing. In fact you cannot stop it changing. The growth, incidentally, that is mentioned in these “grow your brain” reports however, is minuscule, absolutely tiny.
The Brain and Plasticity
The brain consists of 100 billion neurons (precisely 86 billion according to recent research  ) and a host of supporting cells. These neurons build connections, known as synapses, to other cells, and hence a communication channel is opened up. The neurons fire an electrical current, known as an action potential, which is created with an imbalance in chemicals in the brain cell. More than that communication between two cells is driven by a chemical interaction. These connections do not touch but rather there is a minute gap and chemicals are released that “jump” over the gap to keep the chemical process and electrical current moving. It is not like a circuit in computer but more like forest growing and the roots interconnecting. However these connections will grow if they have a lot of stimulation and shrink and disappear if they have no stimulation. So concretely Eric Kandel noted in his fascinating book “In Search of Memory“  that a sensory neuron will have on average 1300 connections to around 25 other cells. Of these only about 40% of these connections are active. If the sensory neuron is continually stimulated these will increase to 2700 connections with 60% active (which is more than 300% activation). This is learning. So continually activating a neuron will stimulate the growth of connections. However, if these habituate or are not used the connections will shrink form 1300 to 850 with only about 100 being active (15 times less than in a stimulated environment). These connections can also only shrink but remain physically intact and so can activate again quickly if needed  – this is the “forgotten but learn again quickly” effect
So simply if you do something new (meaning stimulate the brain in a different way) this will use neurons that are not normally used and hence stimulate growth. If you stop whatever it is, your connections will shrink. This is happening daily. Each day you form new memories. Short-term memories are chemical traces in the brain long-term memories are physical connections. So if you do anything today that you can remember next year that is a physical connection. Learning is creating physical connections in the brain.
So the long and short of it is the brain is continually growing and shrinking and in a wide variety of brain regions depending on what you use on a daily basis. The brain is not just growing it is also shrinking in various areas at the same time. Continually. It is the way the brain is made.
So if you want to grow your brain all you have to do is learn something new. That could be a language – and that is certainly good for many reasons. It could be musical instrument that is also good for many reasons (music does wonderful things for the brain). It could also be doing a course in biology (to learn how the brain grows) or playing any new computer game. It could also be a new sport or starting dancing class – both of which are excellent for many reasons. And what about “brain training games“ well these have been shown to have limited impact and normally only on the type of task you train with little transference to the real world . Certain tasks have been shown to transfer, peripheral vision tasks for example and so-called N-back tasks helping with working, or fluid, memory (which is a key component of IQ ,  ). But the effect seems to be limited though there are better and better products on the market and these are likely better than vegetating in front of the TV. Any active use is better than no use.
What grows the brain most?
This is maybe a misleading questions as it is back to this fascination with growing the brain and assuming growing the brain will make you more intelligent and live longer (this may hold true). Some things you can do for the brain are:
Exercise – yes that simple aerobic exercise has been shown as one of the single most effective factors at slowing down cognitive decline .
Dance – dancing is great for the brain as it combines a multitude of stimuli. Exercise, coordination, balance, music, rhythm, and not forgetting social contact. A study in The New England Journal of Medicine in 2003 showed that those who danced had the lowest risk of dementia in those activities studied .
Social contact – human beings and hence human brains are designed to be social. Socialising is great for the brain it means reacting to conversational cues drawing on language cues but also various coordinative movement as you have a conversation. More than that positive social interaction can also release all sorts of positive chemicals in the brain and it is inherently rewarding (assuming it is positive interaction) [16–23].
Sleep – sleep is the time the brain recovers and grows most. Sleep deprivation has been shown to shrink the brain and give negative chemical imbalances in the brain and body [24–26].
Avoid stress – some stress is natural but long-term chronic stress will severely impact the brain’s functioning and the toxic chemical environment will lead to many disorders and chemical interaction not forgetting diabetes and other such sicknesses. A recent study at Yale University showed that stress can shrink the brain – losing synapses those ever so important connections in the brain , 
Learn something new – anything. Music is good but make sure it is something you enjoy doing and (preferably in a social group).
Think – yes that simple as we said if you don’t use it you lose it. This is why people with cognitive jobs tend to have much lower chances of getting dementia. Many academics keep going till they die with brains sharp and healthy (not all but many). But more than that in the dementia study above playing games was also related to much lower levels of dementia .
Eat good food – you food affects your thought process. This article recently reported that your gut bacteria can influence your thinking processes , but simply having a healthy diet will influence your chemical balance. You brain works on the chemicals produced by your body influenced by what you put into it.
So to sum up remember the brain is an organic environment it is constantly in flux and the interactions you have on a daily level will change the brain in minute ways if these chemical interactions are continually stimulated, this will grow and if they are not used, they will shrink. This is only partly influenced by genetics – all brains grow. When you next read a report that mowing your lawn grows your brain, do not be surprised – it is normal. And please remember to keep using your brain in positive and happy and particularly social ways.
That will keep your brain healthy and growing all your life!
Webinars on “Brains in Business”.
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 J. Mårtensson, J. Eriksson, N. C. Bodammer, M. Lindgren, M. Johansson, L. Nyberg, and M. Lövdén, “Growth of language-related brain areas after foreign language learning.,” NeuroImage, vol. 63, no. 1, pp. 240–4, Oct. 2012.
 E. A. Maguire, K. Woollett, and H. J. Spiers, “London taxi drivers and bus drivers: a structural MRI and neuropsychological analysis.,” Hippocampus, vol. 16, no. 12, pp. 1091–1101, 2006.
 E. Maguire, R. Frackowiak, and C. Frith, “Recalling routes around London: Activation of the right hippocampus in taxi drivers,” Journal of Neuroscience, vol. 17, no. 18, pp. 7103–7110, 1997.
 S. Teki, S. Kumar, K. von Kriegstein, L. Stewart, C. R. Lyness, B. C. J. Moore, B. Capleton, and T. D. Griffiths, “Navigating the Auditory Scene: An Expert Role for the Hippocampus.,” The Journal of neuroscience : the official journal of the Society for Neuroscience, vol. 32, no. 35, pp. 12251–12257, Aug. 2012.
 U. Halsband, S. Mueller, T. Hinterberger, and S. Strickner, “Plasticity changes in the brain in hypnosis and meditation,” Contemporary Hypnosis, vol. 26, no. 4, pp. 194–215, 2009.
 R. J. Haier, S. Karama, L. Leyba, and R. E. Jung, “MRI assessment of cortical thickness and functional activity changes in adolescent girls following three months of practice on a visual-spatial task.,” BMC research notes, vol. 2, no. 1, p. 174, Jan. 2009.
 R. L. Hotz, “Music Leaves Its Mark on the Brain ,” Los Angeles Times, Los Angeles, p. Online, 2002.
 S. Herculano-Houzel, “Brains matter, bodies maybe not: the case for examining neuron numbers irrespective of body size.,” Annals Of The New York Academy Of Sciences, vol. 1225, no. 1, pp. 191–199, 2011.
 E. R. Kandel, In Search of Memory. W. W. Norton & Company, 2006, p. 528.
 S. B. Hofer, T. D. Mrsic-Flogel, T. Bonhoeffer, and M. Hübener, “Experience leaves a lasting structural trace in cortical circuits.,” Nature, vol. 457, no. 7227, pp. 313–317, 2009.
 A. M. Owen, A. Hampshire, J. A. Grahn, R. Stenton, S. Dajani, A. S. Burns, R. J. Howard, and C. G. Ballard, “Putting brain training to the test,” Nature, vol. 465, no. 7299, pp. 1–5, 2010.
 J. T. Shelton, E. M. Elliott, R. A. Matthews, B. D. Hill, and W. D. Gouvier, “The relationships of working memory, secondary memory, and general fluid intelligence: working memory is special.,” Journal of experimental psychology Learning memory and cognition, vol. 36, no. 3, pp. 813–820, 2010.
 R. J. Sternberg, “Increasing fluid intelligence is possible after all,” Proceedings of the National Academy of Sciences of the United States of America, vol. 105, no. 19, pp. 6791–6792, 2008.
 K. I. Erickson, M. W. Voss, R. S. Prakash, C. Basak, A. Szabo, L. Chaddock, J. S. Kim, S. Heo, H. Alves, S. M. White, T. R. Wojcicki, E. Mailey, V. J. Vieira, S. A. Martin, B. D. Pence, J. A. Woods, E. McAuley, and A. F. Kramer, “Exercise training increases size of hippocampus and improves memory.,” Proceedings of the National Academy of Sciences of the United States of America, Jan. 2011.
 “Leisure Activities and the Risk of Dementia in the Elderly — NEJM.” [Online]. Available: http://www.nejm.org/doi/full/10.1056/NEJMoa022252#t=abstract. [Accessed: 11-Oct-2012].
 L. H. Somerville, W. M. Kelley, and T. F. Heatherton, “Self-esteem modulates medial prefrontal cortical responses to evaluative social feedback.,” Cerebral Cortex, vol. 20, no. 12, pp. 3005–3013, 2010.
 K. Fliessbach, B. Weber, P. Trautner, T. Dohmen, U. Sunde, C. E. Elger, and A. Falk, “Social comparison affects reward-related brain activity in the human ventral striatum.,” Science, vol. 318, no. 5854, pp. 1305–8, 2007.
 U. Hess and P. Bourgeois, “You smile–I smile: emotion expression in social interaction.,” Biological Psychology, vol. 84, no. 3, pp. 514–520, 2010.
 A. M. Wood, J. Maltby, R. Gillett, P. A. Linley, and S. Joseph, “The role of gratitude in the development of social support, stress, and depression: Two longitudinal studies,” Journal of Research in Personality, vol. 42, no. 4, pp. 854–871, 2008.
 G. Dumas, J. Nadel, R. Soussignan, J. Martinerie, and L. Garnero, “Inter-Brain Synchronization during Social Interaction,” PLoS ONE, vol. 5, no. 8, p. 10, 2010.
 A. Bandura, Social foundations of thought and action: A social cognitive theory, vol. 1, no. US: Prentice-Hall. Prentice-Hall, 1986, p. 617.
 G. Tabibnia and M. D. Lieberman, “Fairness and cooperation are rewarding: evidence from social cognitive neuroscience.,” Annals Of The New York Academy Of Sciences, vol. 1118, no. 1, pp. 90–101, 2007.
 L. J. Young, M. M. Lim, B. Gingrich, and T. R. Insel, “Cellular mechanisms of social attachment,” Hormones and Behavior, vol. 40, no. 2, pp. 133–138, 2001.
 B. Xu, K. Zang, N. L. Ruff, Y. A. Zhang, S. K. McConnell, M. P. Stryker, and L. F. Reichardt, “Cortical degeneration in the absence of neurotrophin signaling: dendritic retraction and neuronal loss after removal of the receptor TrkB.,” Neuron, vol. 26, no. 1, pp. 233–245, 2000.
 K. Spiegel, R. Leproult, and E. Van Cauter, “Impact of sleep debt on metabolic and endocrine function.,” Lancet, vol. 354, no. 9188, pp. 1435–9, Oct. 1999.
 D. J. Cai and T. C. Rickard, “Reconsidering the role of sleep for motor memory,” Behavioral Neuroscience, vol. 123, no. 6, pp. 1153–1157, 2009.
 H. J. Kang, B. Voleti, T. Hajszan, G. Rajkowska, C. A. Stockmeier, P. Licznerski, A. Lepack, M. S. Majik, L. S. Jeong, M. Banasr, H. Son, and R. S. Duman, “Decreased expression of synapse-related genes and loss of synapses in major depressive disorder.,” Nature medicine, vol. 18, no. 9, pp. 1413–1417, Aug. 2012.
 “YaleNews | Yale team discovers how stress and depression can shrink the brain.” [Online]. Available: http://news.yale.edu/2012/08/12/yale-team-discovers-how-stress-and-depression-can-shrink-brain. [Accessed: 11-Oct-2012].
 M. Costandi, “Microbes Manipulate Your Mind,” Guardian Online, 2012. [Online]. Available: http://www.guardian.co.uk/science/neurophilosophy/2012/aug/19/microbes-manipulate-your-mind. [Accessed: 11-Oct-2012].