Homework 1: How I do an everyday task

How I go down a staircase?

When I am at the top of a staircase, the first input that is processed, leading to the realization that a staircase needs to be traversed, is the visual input. The image of the staircase is recognized as a pattern and classified as a type of 'stairs'. Next I found myself aware of the height and the width (in the forward direction) of each step. I also found myself subtly plotting a route to the end of the staircase*.

The actual descent (carried out one step at a time) began when I lifted a foot (no preference for left or right in my case) and positioned it above the next step (trying to position it exactly in the middle of the next step). Next, the knee of the other leg was bent (slowly at first and let free afterwards), till the foot hit the step. After, quickly balancing myself, I lifted the other foot from the previous step and positioned it above the next step and repeated the above process. The last step is tackled by finally putting both feet on the ground. I remember more than once being surprised at the last step because I was not paying attention and was unaware that the stairs had ended. Thus, I can safely say that I also kept track of the number of steps remaining. I have also found myself judging the parity (odd - even) of the stairs in cases where I was planning to go down 2 steps at a time.

I would like to conclude by stating that this is a process which evolves with practice and more and more steps add to it as one gains experience with the existing ones. I have had the (mis)fortune of having to nurse more than one grandparent who had forgotten all motor skills due to a neurological illness. I taught them to walk and to climb up and down stairs. I found that for them, while learning, only the next step mattered. All of their planning was to get to the next step only. Once they had both feet on the next step, they planned further.

* - Before writing this article, I tried many staircases. However, one in particular, led me to believe that I actually plotted a path to the end of the staircase (or atleast to an intermediate point in case the entire staircase is not visible at once). This staircase was divided into 4 parts. It went down for 5-6 steps, then turned left by 90^o, then again descended for 4-5 steps and turned 90^o, it again descended for 3 steps and turned 90^o, finally it descended for 7-8 steps and included a large last step which was twice the size of the other steps in width but had the same height. The 90^o turns had square connecting tiles. I found that stepping on and off the square connecting tiles could be done in two ways. I could stick to the left side and used the square connecting tile as another step in the staircase or I could first get to the square tile with both feet and then start over (this is necessary if you are descending with another person who already is on the left side). I found that if I were to go with the second option, I only cared about the first part of the staircase till I reached the first connecting tile and so on. I also found myself wishing to take the left side and optimize my path.