“…Behavioral inflexibility that includes impairments in reversal learning, is a common feature of many psychiatric illnesses and neurodegenerative disorders such as schizophrenia, attention-deficit/hyperactivity-disorder (ADHD), drug addiction, depression, Parkinson's or Huntington's diseases (Owen et al, 1992;Lawrence et al, 1999;Swainson et al, 2000;Cools, 2001;Rogers and Robbins, 2001;McLean et al, 2004;Fillmore and Rush, 2006;Waltz and Gold, 2007;Murray et al, 2008;Clark et al, 2009;Shell et al, 2018). Along with brain impairments associated with these diseases, a large literature has shown that across species, the frontal lobe and the basal ganglia (BG) play fundamental roles in enabling the different aspects of behavioral flexibility (Kirkby, 1969;Kolb, 1977;Pisa and Cyr, 1990;Owen et al, 1992;Eslinger and Grattan, 1993;Roberts et al, 1994;Wise et al, 1996;Dias et al, 1996Dias et al, , 1997Birrell and Brown, 2000;Swainson et al, 2000;Collins et al, 2000;Monchi et al, 2001;Cools, 2001;Crofts et al, 2001; Barense et al, 2002;Chudasama and Robbins, 2003;McLean et al, 2004;Ragozzino, 2007;Waltz and Gold, 2007;Floresco et al, 2008).…”