Choice Behavior Two

Complex Choice In a concurrent schedule of reinforcement, two (or more) response alternatives are available at the same time the subject is free to switch from one to the other at any time Just like potluck dinners However, in some (real-life) situations, choosing one alternative makes other alternatives unavailable. Where to go on vacation Which movie to watch in a multiplex Whom to marry In these cases, the choice may involve assessing complex, long-range goals. Concurrent-chain schedule of reinforcement see Figure 6.6 Choice link is a concurrent (A) VI 3 min vs (B) FI 3 min If Response A then VI 3 min schedule in terminal link If Response B then FI 3 min schedule in terminal link

No Switching Figure 6.6 – Diagram of a concurrent-chain schedule. The Principles of Learning and Behavior, 7e by Michael Domjan Copyright © 2015 Wadsworth Publishing, a division of Cengage Learning. All rights reserved.

Differences in delay, not ratios, control choice in concurrent chains (1996) Savastano and Fantino Figure 1

Complex Choice Choice with commitment Used to study Can not switch keys during terminal link Terminal Link stays in effect for fixed period of time Pattern of responding reflects the schedule of reinforcement Used to study preference between reinforcement schedules Pigeons prefer VI 3min over a FI 3min see fig 6.6 delay of reinforcers in the terminal link Conditioned reinforcers "self-control“ by combining different delays with different reward values

Self Control Self-regulation of one's behavior in accordance with personal beliefs, goals, attitudes and societal expectations. Choosing a large delayed reward over an immediate small reward. Which would you prefer? You can have $25 today or $25 a year from now? Subjective Value of $25 decreases the longer you have to wait for it Can determine subjective value of $25 with a series of comparisons You can have $20 today or $25 a year from now? You can have $15 today or $25 a year from now? You can have $10 today or $25 a year from now? Humans have more self-control then other animals and adults show more control then children. Choice of cake now or good health in the “future”

Self Control Concurrent chain schedules have been used to study ‘self-control’ in the lab with procedures for choosing a large delayed reward over an immediate small reward. Value discounting function value of a reward decreases with delay Example of value discounting in humans “college students” Choice between favorite juice in either 16 ml or 8 ml size As the delay gets longer the value decreases More decrease for the smaller 8 ml size See Figure 6.7 Value of a reinforcer is directly related to magnitude and inversely related to delay in delivery

FIGURE 6.7 The subjective value of 16 ml and 8 ml of juice as a function of delay in college students. Curves represent best-fitting hyperboloid functions (based on Jimura et al., 2009). The Principles of Learning and Behavior, 7e by Michael Domjan Copyright © 2015 Wadsworth Publishing, a division of Cengage Learning. All rights reserved.

Self Control Why not always choose the smaller reward? Some delayed rewards are large enough that they are worth waiting for If you need to wait for the small reward it also decreases in value Crossover of discounting functions see Figure 6.8 Both the small and large rewards loose value with delay If the delay for the small reward is long it decreases in value And if the large reward is really large it retains more value than the small reward at T1; a short time to small reward - impulsive choice of small reward at T2: longer wait time - value of large reward greater than the small reward

Figure 6.8 – Hypothetical relations between reward value and waiting time to reward delivery for a small reward and a large reward presented some time later. The Principles of Learning and Behavior, 7e by Michael Domjan Copyright © 2015 Wadsworth Publishing, a division of Cengage Learning. All rights reserved.

Self Control Change in delay function with age Compare Young adults to Senior adults Hypothetical monetary reward after some delay Young adults have a steeper discount function See Figure 6.9 The Principles of Learning and Behavior, 7e by Michael Domjan Copyright © 2015 Wadsworth Publishing, a division of Cengage Learning. All rights reserved.

FIGURE 6.9 Delay discounting for hypothetical monetary rewards among college students and senior adults (mean age 71). Notice that the rate of discounting is significantly slower among the older participants (based on Jimura et al., 2011). The Principles of Learning and Behavior, 7e by Michael Domjan Copyright © 2015 Wadsworth Publishing, a division of Cengage Learning. All rights reserved.

Self Control Individual difference in delay function Self control in Drug Addiction: Madden et al. (1997) heroin-dependent vs nondependent matched controls smaller amount immediately or $1000 in the future delay time to $1000 was varied (1 week to 25 years) heroine-dependent individuals had a steeper discount function Steeper discount function in childhood is predictive of drug abuse Has the same stability as personality traits Important aspect of achievement such as grades in school Impatience and Grades (Kirby, 2005) procedure bid real money in auctions for real delayed rewards two delayed reward amounts, large ($20) and small $(10) delay ranging from 1 to 43 days Discount rates were consistently negatively correlated with GPA Steeper discount rates predicted lower academic performance The Principles of Learning and Behavior, 7e by Michael Domjan Copyright © 2015 Wadsworth Publishing, a division of Cengage Learning. All rights reserved.

Can Self Control be Trained? Nonhuman animals and children behave more impulsively then adults in experimental situation adults have advanced verbal abilities adults have more experience with reinforcement Improve self-control with training by gradually increasing delays to the larger reward or gradually decreasing delays to the smaller reinforcer but impulsive behavior may begin to recur so require the participant to perform distracting activities such as talking or singing

Using a self-control training procedure to increase appropriate behavior Dixon (1998) Working with adult mentally disabled adults To improve self-control Leaving there chairs or not completing training exercises Multiple baseline across participants design see figure 1 Naturalistic baseline Choice baseline between smaller and larger reward Self-control training treatment gradual progressive-duration was introduced on the larger reinforcer