Reaction Time and Uncertainty in Human Information Processing

A series of four experiments was performed based on a model of human information processing. The model postulates four stages in the processing of an external stimulus: encoding (stage 1), central processing (stage 2), response selection, e.e. decoding (stage 3), and response execution (stage 4). The total reaction time can be decomposed into two or more components which reflect the operation of these stages. It is argued that RT=A+B(Hc) where RT is total reaction time, A is the time taken for stages 1 and 3, B is the rate of central processing and Hc is an expression of the uncertainty associated with stage 2. Experiments based on this model investigated high speed scanning of random figures in human memory, retrieval time as a function of memory ensemble size, information processing as a function of speed versus accuracy, and memory retrieval and central comparison times in information processing. The results were consistent with the model, and it proved possible to quantify the rates of steps involved in the stages. (EB)