The multiple components of executive function are difficult to study in humans and animals, however, specific definitions such as dysfunctional impulsivity and impulsive choice have made determinations of deficits in executive psychopathology and frontal brain structure-function studies possible (Congdon and Canli, 2005; de Wit, 2009). Experimental studies suggest that specific frontal cortico-striatal circuits work as stop signals (Aron et al., 2007). Deficits in impulse control are associated with adolescence, Alcohol use disorders (AUD, alcoholism), other drug addiction, attention deficit/hyperactivity disorder (ADHD), anti-social personality disorder and other neuropsychiatric and neurological conditions (Congdon and Canli, 2008; Evenden, 1999). Impulsive choice is one aspect of impulsivity that involves the choice of small, sooner rewards over larger, delayed rewards (Cardinal et al., 2004). Psychological testing has used delay discounting, procedures designed to assess reward value and the ability to delay for greater rewards or to discount the greater reward for smaller immediate rewards. Delayed discounting has been used to assess impulsive choice of small, sooner rewards over larger, delayed rewards. Thus, the present value of a reward decreases as a function of duration of
