Experimental psychology involves studying mental processes and behavior through controlled experiments. It has a long history, with early contributors including Wilhelm Wundt in Germany who studied emotional and mental processes, and Charles Bell who researched the nervous system. Modern experimental techniques involve giving a stimulus to different groups and recording any changes in responses to draw conclusions. Instruments used include electroencephalographs, functional magnetic resonance imaging, and mazes to study areas like perception, sensation, neurology, and experimental psychology.