Effects of methylphenidate on sensitivity to reinforcement delay and to reinforcement amount in pigeons: Implications for impulsive choice.

Abstract

Methylphenidate has been shown to decrease impulsive choice (increase choices of a larger more delayed reinforcer). The purpose of this study was to investigate 2 potential behavioral mechanisms of this effect: a drug-induced change in control by reinforcement delay (Experiment 1) and/or by reinforcement amount (Experiment 2). In Experiment 1, pigeons responded under a rapid-acquisition, concurrent-chains choice procedure involving delay to reinforcement; the option with the shorter delay varied unpredictably across sessions. The pigeons accurately tracked the shorter delay across sessions (i.e., a preference for the option with the shorter delay developed within each session). Methylphenidate selectively decreased sensitivity to reinforcement delay-it attenuated the acquisition of preference at doses that did not systematically affect bias or response rates. In Experiment 2, pigeons responded under a rapid-acquisition, concurrent-chains choice procedure involving reinforcement amount. The pigeons accurately tracked the option with the larger reinforcement amount across sessions. Methylphenidate selectively decreased sensitivity to reinforcement amount-it attenuated the acquisition of preference at doses that did not systematically affect bias or response rates. These data suggest that methylphenidate attenuates the degree to which the various reinforcement dimensions control choice, and that drug effects on impulsive choice depend upon the relative contributions of drug-induced changes in control of behavior by each relevant dimension. (PsycINFO Database Record

Using a dependent schedule to measure risky choice in male rats: Effects of d-amphetamine, methylphenidate, and methamphetamine.

“…Ta et al (2008) found that amphetamine decreases sensitivity to delayed reinforcement, and Maguire et al (2009) observed decreases in sensitivity to reinforcement amount following amphetamine administration. However, although methylphenidate selectively decreased sensitivity to probabilistic reinforcement in the current experiment, Pitts et al (2016) found that methylphenidate decreases sensitivity to delayed reinforcement and sensitivity to reinforcer amount. This discrepancy may due to the species used across experiments (rat in the current experiment; pigeon in Pitts et al, 2016) or may be due to procedural differences.…”

“…Primarily, these studies have tested psychostimulant drug effects on choice controlled by several dimensions of reinforcement, such as delayed reinforcement and reinforcement magnitude. The drugs d -amphetamine and methylphenidate decrease sensitivity to reinforcement delay (Pitts et al, 2016; Ta et al, 2008) and reinforcement amount (Maguire et al, 2009; Pitts et al, 2016). While dependent schedules have been used to assess the neurochemical basis of delayed reinforcement (i.e., impulsive choice), they have not been used to study the neurochemical basis of probability discounting.…”

“…Onge & Floresco, 2009). Methylphenidate and methamphetamine were included because these drugs have been used in commonly used delay-discounting tasks (e.g., Adriani et al, 2004; Evenden & Ryan, 1996; Pardey, Kumar, Goodchild, & Cornish, 2013; Paterson, Wetzler, Hackett, & Hanania, 2012; Pitts & Febbo, 2004; Richards, Sabol, & de Wit, 1999; Siemian, Xue, Blough, & Li, 2017; Slezak & Anderson, 2011; Tanno, Maguire, Henson, & France, 2014; van Gaalen, van Koten, Schoffelmeer, & Vanderschuren, 2006; Wade, de Wit, & Richards, 2000) as well as in concurrent-chains procedures (Maguire et al, 2009; Pitts et al, 2016; Ta et al, 2008) but have not been tested in probability discounting. Also, using these drugs is important as they are known to have high abuse potential in both preclinical (Baladi, Nielsen, Umpierre, Hanson, & Fleckenstein, 2014; Balster & Schuster, 1973; Collins, Weeks, Cooper, Good, & Russell, 1983; Harrod, Dwoskin, Crooks, Klebaur, & Bardo, 2001; Marusich & Bardo, 2009; Munzar, Baumann, Shoaib, & Goldberg, 1999; Pickens, 1968) and clinical populations (Reynolds, Strickland, Stoops, Lile, & Rush, 2017; Rush, Essman, Simpson, & Baker, 2001; Rush, Stoops, Lile, Glaser, & Hays, 2011; Stoops, Glaser, Fillmore, & Rush, 2004; see Stoops, 2008 for a review) and are known to alter risky decision making in humans (e.g., Campbell-Meiklejohn et al, 2012) or alter neural circuits related to risky decision making (Bischoff-Grethe et al, 2017; Ersche et al, 2005; Kohno, Morales, Ghahremani, Hellemann, & London, 2014).…”

Effects of GluN2B-selective antagonists on delay and probability discounting in male rats: Modulation by delay/probability presentation order.

“…To determine if a drug alters sensitivity to reinforcer magnitude, control experiments can be conducted in which subjects respond for reinforcers that differ in magnitude only. For example, Pitts, Cummings, Cummings, Woodcock, and Hughes (2016) tested the effects of methylphenidate on sensitivity to delayed reinforcement and sensitivity to reinforcer magnitude by conducting two experiments. In Experiment 1, the delay to reinforcement differed across two reinforcer alternatives but magnitude was held constant.…”

Rejecting impulsivity as a psychological construct: A theoretical, empirical, and sociocultural argument.

“…Moreover, similar functions have been observed across a wide variety of animal species (Addessi, Paglieri, & Focaroli, 2011; Dandy & Gatch, 2009; Green, Myerson, & Calvert, 2010; Stevens, Hallinan, & Hauser, 2005; see review by Vanderveldt, Oliveira, & Green, 2016). Other work has further isolated the role of delay in intertemporal choices by evaluating other behavioral mechanisms involved, such as magnitude discriminations (e.g., Pitts, Cummings, Cummings, Woodcock, & Hughes, 2016; Pitts & Febbo, 2004; Strickland, Feinstein, Lacy, & Smith, 2016) and probability (e.g., Green & Myerson, 2004).…”