What Intervenes Between the Stimulus and Response?
Most people are able to respond to a task such as Dunk Tank within hundreds of milliseconds. This means that the response is almost instantaneous, but not quite. What accounts for the lag between the turtle speaking and you clicking the mouse button? No one knows for sure. Studies of electrical activity in the brain cortex have shown that when people respond quickly to a reaction-time test, the amplitude of their brain waves is relatively large. When people respond slowly, on the other hand, the amplitude of their brain waves is relatively small, indicating that fast and slow reactions may be distinct phenomena within the brain. Scientists have also studied electrical activity emanating from the brain stem, an area near the top of the spinal cord that controls the body’s automatic and obligatory activity (such as breathing). Here, too, brain stem activity shows different patterns for fast versus slow reaction times. Dunk Tank is a relatively simple task with a single stimulus and a sin
