The phenomenom of not being able to find something you are looking for and then being shown that it is somewhere you have already checked is well known. It is attributed to inattentional blindness - the failure to perceive an object in plain sight when there are too many stimuli in view. I have found that the exact opposite is the case, hence my use of the term ‘attentional blindness’. The visual system can hide an object that is being looked at directly.
My DIY equipment is stored in the kind of state of ordered chaos that, I presume, many are familiar with. While apparently piled ad hoc on shelves, I know where everything is. One day I went to get my steel measuring tape but it was not in its place. I searched around the house in places where I might have left it but it was nowhere to be found. I went back to the cupboard in case I had simply failed to see it the first time but it was still not there so I made do with my 1·2m ruler.
About three weeks later I again went to get the tape measure having forgotten that it was missing. I noticed that there was no measured-shaped dust-free patch on the shelf. It seemed that the measure must have been missing for some time but there should still have been a noticeable difference between the dust inside and out of where the measure had been.
About a week later I went to the cupboard to get a mains extension lead and there was the tape measure. I picked it up and underneath was free of dust. My visual system, for some reason, had blocked the measure from view by replicating the surrounding shelf into the area it occupied.
Some time after I went to the kitchen to get a glass for a drink of water. I like to use my glasses in rotation so I put the next glass to be used on the worktop. The expected glass was missing so I checked in other rooms in case I had left it somewhere else. I could not find it so I went back to the kitchen and got another glass out of the cupboard right below where the glass should have been. I stood up, glass in hand, intending to put it on the worktop but the glass that I had been looking had now magically appeared. In both this case and the previous it seems that my visual system only hides the object when I am actively looking for it.
I was working on a computer program. I went to open a new source file. The files in the folder are listed in alphabetical order so I knew exactly where the file should appear in the list. However what I saw was a yellowed line where it should be.
© Copyright 2021 Andrew Jarvis.