An inexpensive and accurate method of measuring the force of responses in reaction time research

Together with reaction time (RT), the force with which people respond to stimuli can provide important clues about cognitive and affective processes. We discuss some of the issues surrounding the accurate measurement and interpretation of response force, and present a response key by which response force can be measured regularly and unobtrusively in RT research. The advantage of the response key described is that it operates like a standard response key of the type used regularly in classic RT experiments. The construction of the response key is described in detail and its potential assessed by way of an experiment examining response force in a simple reaction task to visual stimuli of increasing brightness and size.