5.5.1. In Action (2)
In choosing this task, I made use of the fact that color discrimination is poor in peripheral vision [Hack #14] . By fixing my gaze at a position directly opposite me, over the road, and refusing to move my eyes or my head, I would be able to tell the color of each car only as it passed directly in front of me. (If I had chosen to discriminate black cars and white cars, there’s no color information required, so I would have been able to tell using my peripheral vision.) I wanted to do this so I wouldn’t have much time to do my color task, but would be able to filter out moving objects that weren’t cars (like people with strollers).
As a response, I tapped my right knee every time a red car passed and my left for blue ones, trying to respond as quickly as possible.
After 10 minutes of slow but steady traffic, I could discern a slight bias in my responses. My right hand would sometimes twitch a little if cars approached from that direction, and vice versa.
Now, I wouldn’t be happy claiming a feeling of a twitchy hand as any kind of confirmation of the Simon Effect. The concept of location in my experiment is a little blurred: cars that appear from the right are also in motion to the leftwhich stimulus location should be interfering with my knee-tapping response?
But even though I can’t fully claim the entire effect, that a car on the right causes a twitching right hand, I can still claim the basic interference effect: although I’d been doing the experiment for 10 minutes, my responses were still getting mucked up somehow.
To test whether my lack of agility at responding was caused by the location of the cars conflicting with the location of my knees, I changed my output, speaking “red” or “blue” as a response instead. In theory, this should remove the impact of the Simon Effect (because I was taking away the left-or-right location component of my response), and I might feel a difference. If I felt a difference, that would be the Simon Effect, and then its lack, in action.
And indeed, I did feel a difference. Using a spoken output, responding to the color of the cars was absolutely trivial, a very different experience from the knee tapping and instantly more fluid.
Taken from : Mind Hacks
