Online – VCE – Psychology UNIT 4 : Sleep Year 12 Medical Technologies A sleep unit is available for purchase to schools. The set of 3 videos show a Keynote on Sleep, the sensors being placed on the body and the wavelengths of the person going to sleep. VCE – Psychology UNIT 4 : Sleep Year 12 Medical Technologies How do external factors influence behaviour and mental processes? In conjunction with the Epworth Sleep Lab, students undertake a comprehensive sleep education session.