Donder's work attempts to describe the processes going on in the mind, by analyzing cognitive activity into separate stages. Until Donder's work, many scientists had assumed that the mental operations involved in responding to a stimulus occurred instantaneously.
Donder was particularly interested in "timing the mind" and used a subtraction technique to time the different mental processes that the brain goes through when faced with different tasks.
Donders performed experiments using reaction time tasks in 1868. His was the first attempt to analyze and measure the component processes of a simple task.
1. a simple reaction time task - e.g. you are seated in front of a panel that contains a light bulb and a response button. When the light comes on, you must press the button.
2. a choice reaction time task - e.g. you are seated in front of a panel with 2 light bulbs each with their own response button (modern days on a computer -J for when the left light comes on and K for the right light) When the target light goes on you must press the button corresponding to the appropriate light.
Donder's then predicted the kinds of processes that might be involved in each task :
1. A simple reaction time task would require :
1. Presentation of the stimulus (the light)
2. Which causes a mental response (perceiving the light)
3. Which leads to a behavioural response (pushing the button)
2. A choice reaction time task requires
1. Presentation of the stimulus (the light)
2. Which causes a mental response
• perceiving the light and
• deciding which light was illuminated and then which button to press
3. Which leads to a behavioural response (pushing the button)
As expected, simple tasks take the shortest amount of time, followed choice tasks taking the longest amount