b&w photograph C1&2: Very good condition Dr. Paul Valiant is opening an operant chamber that holds a white lab rat. Similar to photos 03.04.0118 and 03.04.0120. In this experiment rats pressed a lever for a nip of alcohol. Valiant was studying how the rats reacted when they had to work harder and harder, elevating their stress levels, to get the same quantity of alcohol. C1 & C2: Stamped on back: 'Saint Mary's Information Services'. Came in envelope marked 'Psychology 78-79 80-81'. C1: Written in pen: '78-79' (79 encircled).