Why do so many of us enjoy going for a hike? Sure, there is beauty in what we see. But what makes it beautiful? We can try and explain it by saying that colours are beautiful or that being in nature makes us feel good. Look at the picture below and what do you notice first, and do you get a positive feeling?
When you look at the picture above your attention is immediately drawn to the vertical lines that are the cliffs and then the they are drawn the yellow canoe in the foreground. Then we take in the rest of the picture and realize it is pleasant to observe. No doubt it is a beautiful scene but what makes it so beautiful? After all what we see is no more then our eyes and visual neuron in our brains observing the angle at which light bounces off an object. This image can easily be broken down into tiny bits of data that can be analyzed by a computer just like our brains, and if the computer can analyze the same data our brains can, you would think it should be able to predict how we will react to any image.
In the picture above our eyes are drawn to vertical lines and bright colours because the neurons in our brains are programmed for that from prehistoric times. Imagine our ancestors walking through a forest where fruit that is ripe is colourful when it is ready to eat if you were proficient at finding bright colourful ripe fruit you would be a healthy and happy human that would have a survival advantage over another human that was not as skilled at finding bright colourful food. Because of being healthier you would likely have more offspring and pass on this trait. However, fruit does not always grow on the ground it can grow high up in trees, and if everyone else is looking for fruit at eye level or on the ground there is a lot of competition, but if you developed the skill of looking at the tops of trees for food you would have less competition then the other prehistoric humans and would again be healthier and happy, you would pass these traits on to your offspring. As a result, our eyes are drawn to vertical lines and bright colours because it has historically helped us survive.
The reasons we react to images in the way we do comes from our preprogrammed survival instincts not from abstract unknowns. Those ancient humans that developed reactions that promoted survival when presented with certain visual stimulus (think ripe fruit atop a tall tree) would have survived and passed these traits on, those that had different or opposite reactions to the same visual stimulus would not survive and die off. Now you might be thinking that you don’t think about any of these things when you walk in the forest, but the thinking part of the brain is the prefrontal cortex, there is a lot going on in other parts of our brains that we do not even know occurs our eyes communicate with the occipital lobe. Our limbic brain takes this information and creates a feeling such as fear or excitement. The limbic brain is not capable of explaining itself with words, for example when you see a wild animal running at you immediately have a feeling of fear and you turn and run or prepare to defend yourself, before you even think about what the animal will do you have already felt the fear and had your initial reaction and how we process visual stimulus is the same thing. Visual images generate a feeling which in turn makes us have a positive or negative reaction, and then we use our frontal cortex to explain why we like or dislike the image.
When you hike you give your limbic brain many opportunities to be exposed to positive stimulus, which in turn generate positive feelings. The more positive feeling you have the more you associate hiking with positive feelings and the more you want to get out there and hike. It is a win for your brain, it is a win for you. And even better there are no adverse side effects the next morning.