I earned an M.A. and a Ph.D. in experimental psychology from the University of California, Santa Barbara, where I used rats to investigate dopaminergic mechanisms underlying food reinforcement. (sciencemag.org)
However, motivational abnormalities were again found using more complex operant paradigms: BAC HD mice were as or more willing than age - matched control mice to work on a low - effort task (an FR5 schedule) for food reinforcement, but stopped responding more rapidly than did controls when the effort required for reinforcement increased (a progressive ratio task). (psychogenics.com)
In terms of measuring preference, dog social behaviors are highly susceptible to prior patterns of food reinforcement (Bentosela et al., 2008; Elgier et al. 2009), and dogs frequently treat interaction with their owner as an avenue to acquire food (Cook et al., 2014a), even suppressing interest in food under communicative situations (Pongrácz et al., 2013). (academic.oup.com)