Busting Common Myths About the Brain

By: Angela Peter, BSc Neuroscience,

Neuroscience is the study of the brain and nervous system, it is a fascinating topic. However, it is surrounded by many misconceptions. Ideas such as “we only use 10% of our brain” or “some people are left-brained while others are right-brained” have circulated, even though years of research have shown that they are inaccurate. These myths may sound believable but that is often because they contain a small piece of scientific truth that has been exaggerated or misunderstood. In this post, I will dive into eight common myths about the brain, and explain what scientific research actually tells us.

Myth 1: We Only Use 10% of Our Brain

Brain-imaging techniques such as functional magnetic resonance imaging (fMRI) and positron emission tomography (PET) show that activity occurs all throughout the brain. Different areas become more or less active depending on what we are doing. Even during sleep, the brain remains busy regulating the body, processing information and strengthening memories. Although every region is not working at its highest level at the same moment, this does not mean the remaining areas are unused.

Takeaway: We use all parts of the brain, but different networks become active at different times.

Myth 2: Brain Damage Is Always Permanent

Brain injuries can cause serious and lasting changes, but the outcome is not always fixed. Neuroplasticity is the brain's ability to change its connections, and reorganize its activity in response to experience or injury. Rehabilitation can help some people regain skills, or develop new ways of completing tasks (Cramer et al., 2011). However, recovery depends on many factors, including the location and severity of the injury, a person's overall health and access to treatment. Neuroplasticity does not necessarily  mean that every injury can be completely reversed, but rehabilitation offers a window into strengthening most areas of the brain. Certain games and activities, such as those found in the Building Brains Together curriculum can be very beneficial for brain rehabilitation after injuries. 

Takeaway: The brain can adapt after injury, although the amount of recovery varies for every person.  

Myth 3: Listening to Classical Music Makes Babies Smarter

The “Mozart effect” became very popular through the belief that listening to classical music could increase intelligence. The original research only suggested a short-term improvement on a particular spatial task, and later studies struggled to even reproduce this effect consistently (Steele, Bass, & Crook, 1999). Listening to music can still support enjoyment, connection and mood. Actively learning music can also build listening and motor skills, but it should not be promoted as a guaranteed way to raise a child's IQ. Building Brains Together activities that involve rhythm, movement, memory and following instructions allow children to practice important cognitive, and motor skills through play. 

Takeaway: Music is valuable and enriching, but playing Mozart does not make a baby smarter.

Myth 4: A Bigger Brain Means Greater Intelligence

Brain size has a modest relationship with some measures of intelligence among humans, but size alone cannot explain a person's abilities (Deary, Penke, & Johnson, 2010). The organization and efficiency of brain networks, along with genetics, health, education and life experiences, all heavily contribute to cognitive performance. A larger brain therefore does not automatically mean that a person will be more intelligent.

Takeaway: Intelligence cannot be determined by brain size alone.

Myth 5: Multitasking Makes Us More Productive

When people believe they are multitasking, the brain is usually switching very quickly between tasks. Each switch requires the brain to stop one set of its processes, redirect attention, and begin another. Rubinstein, Meyer and Evans (2001) found that task switching creates measurable time costs, especially when tasks are unfamiliar or complicated. For example, a student who repeatedly checks their phone while studying may take longer to finish and have more difficulty remembering what they learned. Activities in our Building Brains Together curriculum encourage children to practice focusing, remembering instructions and controlling their responses through play. These executive-function skills can help children learn how to manage their attention and complete tasks without becoming distracted. 

Takeaway: Focusing on one demanding task at a time is usually more efficient.

Myth 6:  People Are Either Left-Brained or Right-Brained

Certain functions are more associated with one hemisphere. For example, language is commonly more left-lateralized, while some aspects of spatial processing involve the right hemisphere. However, Nielsen and colleagues (2013) found no evidence that people only rely on one hemisphere in a way that creates a more “logical” or “creative” personality type. Creativity, reasoning and problem solving depend on communication across many regions on both sides of the brain.

Takeaway: Both hemispheres have specialized roles, but they work together as a team.

Myth 7: Adults Cannot Grow New Brain Cells

For many years, scientists believed that people were born with nearly all the neurons they would ever have. Eriksson and colleagues (1998) later reported evidence of new neurons forming in the adult hippocampus, a region involved in learning and memory. More recent research using modern genetic methods has strengthened the evidence that neural precursor cells remain in the adult human hippocampus (Dumitru et al., 2025). However, scientists are still studying how many new neurons are produced, how this changes with age and exactly how much these cells contribute to human behaviour. Even beyond neurogenesis, the adult brain can continue changing by strengthening, weakening and reorganizing connections between existing neurons.

Takeaway: The adult brain remains capable of change, and evidence suggests that limited neuron formation continues in the hippocampus.

Myth 8: Emotions and Rational Thought Are Separate

Emotion and reasoning are sometimes described as opposites, but the brain does not separate them so easily. Areas of the prefrontal cortex communicate with regions involved in emotion, memory and body signals when people make decisions. Damasio (1994) showed that when brain damage interferes with emotional processing, decision making can also become seriously impaired. Emotions help us judge what matters, recognize risk and choose between options, while reasoning helps us interpret and regulate emotional responses.

Takeaway: Emotion and logic work together when we make decisions.

Conclusion

Brain myths are widespread, but the real science is usually more interesting than the misconception. The brain is not divided into used and unused portions, one hemisphere does not define our entire personality, and development does not suddenly stop when we reach adulthood. At the same time, ideas such as neuroplasticity should not be exaggerated into promises that the brain can recover from every injury. The human brain is complex, connected and constantly responding to experience throughout life. The Building Brains Together website offers a wealth of resources, free courses, and play-based activities designed to help strengthen cognitive skills throughout the lifespan. These resources provide practical ways for people of all ages to support attention, memory, problem-solving and overall brain health in their everyday lives.

References

Cramer, S. C., Sur, M., Dobkin, B. H., O'Brien, C., Sanger, T. D., Trojanowski, J. Q., et al. (2011). Harnessing neuroplasticity for clinical applications. Brain, 134(6), 1591–1609.https://doi.org/10.1093/brain/awr039

Damasio, A. (1994). Descartes' error: Emotion, reason, and the human brain. Putnam.

Deary, I. J., Penke, L., & Johnson, W. (2010). The neuroscience of human intelligence differences. Nature Reviews Neuroscience, 11(3), 201–211.https://doi.org/10.1038/nrn2793

Dumitru, I., et al. (2025). Identification of proliferating neural progenitors in the adult human hippocampus. Science, 389, 58–63.https://doi.org/10.1126/science.adu9575

Eriksson, P. S., Perfilieva, E., Björk-Eriksson, T., Alborn, A. M., Nordborg, C., Peterson, D. A., & Gage, F. H. (1998). Neurogenesis in the adult human hippocampus. Nature Medicine, 4(11), 1313–1317.https://doi.org/10.1038/3305

Nielsen, J. A., Zielinski, B. A., Ferguson, M. A., Lainhart, J. E., & Anderson, J. S. (2013). An evaluation of the left-brain versus right-brain hypothesis with resting state functional connectivity MRI. PLOS ONE, 8(8), e71275.https://doi.org/10.1371/journal.pone.0071275

Rubinstein, J. S., Meyer, D. E., & Evans, J. E. (2001). Executive control of cognitive processes in task switching. Journal of Experimental Psychology: Human Perception and Performance, 27(4), 763–797.https://doi.org/10.1037/0096-1523.27.4.763

Steele, K. M., Bass, K. E., & Crook, M. D. (1999). The mystery of the Mozart effect: Failure to replicate. Psychological Science, 10(4), 366–369.https://doi.org/10.1111/1467-9280.00169