Progressive-ratio schedules and applied behavior analysis.

Establishing appropriate relations between the basic and applied areas of behavior analysis has been of long and persistent interest to me (e.g., Friman & Poling, 1996; Poling, Picker, Grossett, Hall-Johnson, & Holbrook, 1981; Porritt, Van Wagner, & Poling, 2009). Therefore, I read with enthusiasm the collection of articles on progressive-ratio (PR) schedules that appeared in the Summer 2008 issue the Journal of Applied Behavior Analysis (JABA). For nearly 50 years, since they were first described by Hodos (1961), such schedules have been used in basic research published in the Journal of the Experimental Analysis of Behavior and elsewhere to measure what is commonly termed the strength, potency, or effectiveness of scheduled reinforcers. (The three terms appear to be synonymous, and hereafter I will use only potency.) The essential logic, reflected in all of the JABA articles, is that there is a direct relation between how hard an organism will work for access to an object or activity, as indexed by the largest ratio completed under a PR schedule (the breaking point), and the potency of the reinforcer. It is important to recognize that reinforcer potency is a hypothetical construct, and prominent behavior analysts have argued consistently and compellingly that hypothetical constructs play no useful role in a science of behavior (e.g., Michael, 2004; Skinner, 1938). Unlike, for example, reinforcer delay or magnitude, reinforcer potency is not measured directly, but is instead inferred on the basis of how the scheduled event interacts with ongoing behavior. PR breaking strength is one measure of this interaction, but many others are tenable, including amount of time spent interacting with a reinforcer (think Premack principle), rate of responding engendered by a reinforcer, preference for a reinforcer (think matching equation), demand (in the behavioral economics sense) for a reinforcer, and resistance to disruption of behavior maintained by a reinforcer (behavioral momentum). Although I will not attempt to review the relevant literature, basic and applied studies (including those published in the JABA collection on PR schedules) make it clear that these measures are not necessarily equivalent. As an example, consider cocaine. Acute administrations of the drug reduce self-reported craving for food in humans as well as food intake in humans and nonhumans alike, but they increase PR breaking points at low to moderate doses (Jones, LeSage, Sundby, & Poling, 1995; Sizemore, Cannon, Smith, & Dworkin, 2003; Thompson, 1977). Does the drug increase the reinforcing potency of food and act as an establishing operation (EO), as suggested by PR breaking points, or decrease it and act as an abolishing operation (AO), as suggested by craving and consumption? As a second example, consider methylphenidate. A PR study with rats indicated that the drug increases breaking points for food reinforcers, suggesting that the drug is an EO (Poncelet, Chermat, Soubrie, & Simon, 1983). This suggestion is inconsistent with results of an experiment by Northup, Fusilier, Swanson, Roane, and Borrero (1997), who studied young people diagnosed with attention Please address correspondence to Alan Poling, Department of Psychology, Western Michigan University, Kalamazoo, Michigan 49008 (e-mail: [email protected]). doi: 10.1901/jaba.2010.43-347 JOURNAL OF APPLIED BEHAVIOR ANALYSIS 2010, 43, 347–349 NUMBER 2 (SUMMER 2010)