This Btuiy iitilized a choice method to assess preference in adult rats Vho had been exposed to one of fonr treatments (Sucrose; Quinine; Water; and Handling) at an early age. The up and down (psychophysical) method (Dixon & Ilassey, 1957) vas used to determine the mean concentration of sucrose, Vhich Vhen mixed vith a set concentration of quinine, is Isohedonic (equally preferred) to a set concentration of sucrose (standard). Responses cltistered around a mean score (quinineeucx'ose mixture) vhich is hypothetically equivalent (equally preferred) to a fixed concentration of sucrose (standard). Sensitivity to quinine vas reflected by the response frequencies recorded since the rat vill Ingest the sucrose solution of greater concentration in a tvo choice situation (Young & Green, 1953)-