We all know that competition can bring out a stronger performance than would normally be expected. Nonetheless, with respect to the speed at which the nervous system can generate a response to sensory signals, it is unclear why the reaction time to two tandem signals can be faster than what is provided to each given alone. Some form of pooling or mutual activation of the two signal streams must be at work, resulting in faster processing than would occur if only one signal were being displayed.
This research examined reaction time to single or tandem stimulus signals, and monitored the location of brain activation. The results suggest that the mutual activation of signals is taking place at a rather central junction between sensory and motor processing systems.
