Stumped but learning!

Periodically I get requests to answer questions from students. I always try to be accommodating as it is fun to share my passion for veterinary medicine. Well, I got completely stumped on Thursday by a young man in grade six. I couldn’t answer either of his questions!!

Question number one: how heavy is the human’s brain compared to a dog’s brain? Question number two: if human’s only use 10% of their brain, how much of their brain would a dog use? Holy cow!!!

Here is what I have learned:

The average brain size of a human is 3lbs or 1,400 grams. Dolphins have roughly the same size while elephants’ brains are five times larger. On average, the dogs’ brain is 72 grams in size. There is a large range on this as Chihuahuas certainly have a different brain size compared to Great Danes.

The concept that humans only use 10% of their brain is a myth. There has been significant research using brain imaging techniques such as PET (positron emission tomography) scans and fMRI (functional magnetic resonance imaging) showing we use 100% of our brain. So, dogs do too!!

Let’s compare our brain function to our muscles function. While typing on my computer I am only actively using my fingers and arms to type. When trying to do yoga, I use many different muscle groups during the hour (and feel many others the next day!). We use a variety of areas of our brain for different behaviours. Not a lot of brain power is required for watching TV but when learning a new language many areas of the brain are used.

I also learned that if you were to lay out all the neurons in your brain out end to end it would cover 600 miles.