Specializing in software and hardware tools for human behavioral research, assessment, and education, Psychology Software Tools, Inc. Psychology Software Tools (PST) offfers stimulus presentation software E-Prime®.- providing a asy-to-use environment for computerized experiment design, data collection, and analysis. E-Prime and Chronos® deliver millisecond-accurate stimulus presentation, responses, and sound output. PST also offers a hardware product line of advanced solutions for fMRI research, including an MRI Simulator, Digital Projection System, Button Response System, and Noise Cancellation Microphone.