Economics, Ecologics, and Mechanics: The Dynamics of Responding Under Conditions of Varying Motivation

Abstract

The mechanics of behavior developed by Killeen (1994) is extended to deal with deprivation and satiation and with recovery of arousal at the beginning of sessions. The extended theory is validated against satiation curves and within-session changes in response rates. Anornalies, such as (a) the positive correlation between magnitude of an incentive and response rates in some contexts and a negative correlation in other contexts and (b) the greater prominence of incentive effects when magnitude is varied within the session rather than between sessions, are explained in terms of the basic interplay of drive and incentive motivation. The models are applied to data from closed economies in which changes of satiation levels play a key role in determining the changes in behavior. Relaxation of various assumptions leads to closed-form models for response rates and demand functions in these contexts, ones that show reasonable accord with the data and reinforce arguments for unit price as a controlling variable. The central role of deprivation level in this treatment distinguishes it from economic models. It is argued that traditional experiments should be redesigned to reveal basic principles, that ecologic experiments should be redesigned to test the applicability of those principles in more natural contexts, and that behavioral economics should consist of the applications of these principles to economic contexts, not the adoption of economic models as alternatives to behavioral analysis. goods, and the ecologic organism behaves to minimize deviations from optimal setpoints in its parameter space. Mechanics focuses on the efficient rather than the final causes of behavior, and provides a set of formal causes-a set of mathematical models-that expands simple assertions of causal agency into more precise functional relations between variables. The mechanical organism is not behaving to optimize anything; incitement makes it active, satiation decreases its excitability, and co-occurrence of particular responses with incentives increases the probability of those responses. The primary goal of this paper is to develop the mechanics to the point at which it is applicable to the experimental contexts that are favored by economic and ecologic theorists.

Rats don’t always respond faster for more food: The paradoxical incentive effect

“…It is conceivable that the two-pellet condition decreased hunger more than it increased the incentive motivation conferred by the second pellet of food (Killeen, 1995). Perhaps the rats in the two-pellet condition were simply less hungry.…”

Operant variability when reinforcement is delayed

“…The particular function is hyperbolic, but apart from its decreasing monotonicity, the function's particular form is not critical for our discussion. (Killeen [1995] and Killeen & Sitomer [2003] provide much evidence for a related theory.) As can be seen in the top panel, when responding is relatively distant from a potential reinforcer, elicited variability is high; and as the reinforcer is approached, elicited variability decreases.…”

Chronic stress impairs spatial memory and motivation for reward without disrupting motor ability and motivation to explore.

“…An animal that is more motivated will maintain high responding when confronted with higher work requirements, reflected through MPR as a higher value of a (Killeen, 1995).…”