Models for response-response compatibility: The effects of the relation between responses in a choice task

A simple model is presented that consists of a stimulus-discrimination module and a motor-programming module. The motor-programming module is intended to account for RR-compatibility effects in different types of task. In combination with the stimulus-discrimination module, it is applied to a choice-RT task in which subjects have to perform rapid movements with the left or right hand in response to a left or right signal. The spatio-temporal patterns of the movements that have to be performed with the one or the other hand can be same or different. In the model the relation between the responses is mapped on the strength of inhibitory crosstalk between concurrent processes of motor programming. The stimulus-discrimination module implements a variant of an accumulator model or a random-walk model, and the transmission of information to the programming module can be continuous or discrete. Data that were generated by a model with discrete transmission were inconsistent with available experimental data. With continuous transmission, RR-compatibility effects can result from inhibitory crosstalk during concurrent processes of motor programming after presentation of the response signal and/or from the limiting effect of crosstalk on the level of pre-programming.