25 fascinating facts about the human brain

Here are 25 fascinating facts about the human brain that many people may not be aware of:

Brain Size and Composition

1. Weight and Texture: The average adult human brain weighs about 1.36kg and has a texture like firm jelly.
2. Water Content: Approximately 73-75% of the brain is made up of water. This means that dehydration, even as small as 2%, can have a negative effect on brain functions.
3. Fat Content: The brain is the fattiest organ in the body, consisting of at least 60% fat.

Brain Development

4. Growth in Early Life: The human brain triples its weight in the first couple of years and continues to grow until around age 18. It reaches full maturity mid-to-late 20s.
5. Brain Maturity: The frontal lobes (prefrontal cortex), which control planning and reasoning, are the last to strengthen and structure connections.

Brain Function and Activity

6. Unique Brain Activity: Each person’s brain activity is as unique as their fingerprints. This uniqueness is the result of a combination of genetic factors and individual life experiences.
7. Neuron and Synapse Numbers: The brain contains about 86 billion neurons, each forming connections that can add up to an an amount that is far too large for the human brain to fathom.
8. Speed of Information: Brain signals can travel up to 200+ miles per hour. Not all brains agree with an exact or maximum speed.
9. Constant Activity: The brain is always active, even when sleeping, debunking the myth that we only use 10% of our brain. A certain amount is used for a specific areas of focus. The rest of the brain is doing involuntary actions.

Memory and Learning

10. Memory Capacity: The human brain’s memory size can hold the equivalent of 2.5 million gigabytes of data or 2.5 petabytes. (2,500,000,000,000,000 bytes)
11. Short Term Memory: Short-term memory lasts about 20-30 seconds. Generally, recall is somewhat better for random numbers than for random letters (Jacobs, 1887) and also often slightly better for information we hear (acoustic encoding) rather than information we see (visual encoding) (Anderson, 1969). Memory – EdTech Books
12. Hippocampus and Memory: The hippocampus grows larger with more information to memorize, such as in the interesting case study of London’s taxi drivers. In a randomized controlled trial with 120 older adults, that aerobic exercise training increases the size of the anterior hippocampus, leading to improvements in spatial memory.

Pain and Sensation

13. No Pain Receptors in the Brain: The brain itself does not have pain receptors, making brain surgery possible without pain. This makes awake brain surgery possible.
14. Brain Freezes: Brain freezes, cold neuralgia or sphenopalatine ganglioneuralgia, are caused by the constriction and dilation of blood vessels in the throat or roof of the mouth in response to cold. (Scientists aren’t exactly sure what specifically causes brain freeze.)

Multitasking and Focus

15. Context-Switching: What we perceive as multitasking is actually context-switching, which can increase error rates and time to complete tasks. A study conducted by the University of California shows that it takes, on average, 23-minutes to regain focus after a distraction. When we switch context, we ask our brain to change focus while retaining focus. For example, watching sport while trying to bake a cake.

Emotional and Social Functions

16. Love and Brain Activity: Studies have shown that romantic love is associated with high activity in brain areas related to reward, motivation, emotion, and social functioning. When we are falling in love, chemicals associated with the reward circuit flood our brain.
17. Emotions During Dreams: The limbic system, including the amygdala, is active during dreams, indicating that emotions are processed even when sleeping. Neuroimaging studies reveal significant activity increases during REM sleep in emotion-related regions.

Physical and Cognitive Health

18. Impact of Dehydration: Even mild dehydration can negatively affect brain functions such as memory and attention.
19. Body Health and Brain Health: The health of the body, particularly what you eat and drink, significantly impacts brain performance.
20. Physical Fitness and Dementia: Highly physically fit individuals are less likely to develop dementia. This came from some analysis that combined the results of 58 studies into exercise and dementia.

Brain Structure and Complexity

21. Variety of Cell Types: The brain has more cell types than any other tissue in the human body, contributing to its complexity. The most common brain cells are neurons and non-neuron cells.
22. Brain Anatomy Uniqueness: No two people including twins have the same brain anatomy due to individual experiences and genetics. Anatomically-speaking, each of our brains is very similar; however, when it comes to the manner in which the brain works, each is completely different.
23. Visual Areas: The visual areas of the brain, located in the occipital lobe, are in the back of the brain, which is in the most posterior region of the brain.

Miscellaneous Facts

24. Blood Vessels: A typical human adult’s skull contains approximately 1500 grams of the brain (including gray matter and white matter) and 100-130 milliliters of blood.
25. Power Consumption: The human brain runs on about 20 watts of power, equivalent to the power needed easily light a small LED light. The brain alone consumes +- 20% of the body’s chemical energy.

Neuroscientists have not yet generated a theory explaining how brains work. These facts highlight the intricate and complex nature of the human brain, revealing its unique characteristics, functions, and the ongoing discoveries in neuroscience.