Introduction

A phenomenon that we have exploited in a number of studies in the Eye Lab is saccadic suppression of displacement. This is an effect whereby the movement of objects in the visual world (i.e. displacements) are not detected very well if they occur while the eyes themselves are making a fast movement (saccade).

This effect is difficult to demonstrate on the web as it requires that the change in the stimulus is synchronised with the occurrence of a saccade, which we need an eye tracker to measure. However, saccadic suppression is a subset of the more general phenomenon of change blindness, and this we can demonstrate.

Change blindness is the phenomenon whereby humans are very poor at detecting a change to an object (e.g. its colour, orientation, position, and even appearance and disappearance) if that change occurs simultaneously with a more global change (such as the entire view being blanked for a moment).

The images on the following pages are approximately 145 kB each, so may take some time to download depending on the speed of your internet connection. So you might need to be patient , but let's go to the first step in the demonstration...

 

This demonstration was created by Michael MacAskill. A set of larger images are available which are more suited for PowerPoint or Keynote presentations- contact me if you would like them.