“…This allows for researchers to use breakpoint-the maximum ratio at which animals will respond for reinforcer delivery-to assess relative measures of motivation across groups (Hodos, 1961;Hodos & Kalman, 1963;Richardson & Roberts, 1996). Progressive ratio tasks are widely used and applied to basic science questions across behavioral pharmacology and systems neuroscience fields to assess motivation for various reinforcers, such as drugs of abuse, food, water, and others (Gancarz et al, 2012;Hamill et al, 1999;Randall et al, 2012;Randall, Lee, Nunes, et al, 2014;Randall, Lee, Podurgiel, et al, 2014;Reilly, 1999;Rotolo et al, 2019Rotolo et al, , 2020Rowlett, 2000;Yohn et al, 2018;Zhang et al, 2007). They are also widely use in preclinical research to understand how environmental and genetic factors contribute to behavioral dysregulation in disease.…”