Aversive functions of response effort: Fact or artifact?

Historically, effort has been viewed as aversive. Most supporting evidence comes from studies demonstrating increased force/effort requirements reduce operant responding. Changes in force/effort requirements, however, are often accompanied by changes in response definition when mechanical devices are used to define the response. As a consequence, responses measured at one point in a study may go unmeasured at other points. In an alternative approach, we used a continuous measurement strategy that provided a means to fix the threshold force defining the response class and simultaneously allowed independent manipulation of the force criteria required to produce reinforcement. Rats pressed a force transducer according to a fixed‐ratio 5 schedule of food delivery. The criterion force was systematically increased and decreased; the threshold for response detection was constant. When response rates included only criterion responses, overall rate decreased when force requirements increased. By contrast, when all responses, both those meeting force criteria and those that did not (above the threshold but below the criteria for reinforcement) were included in the rate calculation, increases in force increased response rate. Increases in force criteria also increased the maximum force (g) and time‐integral of force (g‐s) of operant behavior. Control conditions showed increases in responding could be explained by the emergence of subcriterion responses, irrespective of force. We conclude that prior results showing effort decreases response rates are due to an artifact arising from inadvertent changes in response definitions. Increases in effort may better be understood as changes in the response:reinforcer payoff owing to the emergence of a subcriterion response class.     

Prediction of calcaneal bone competence from biomechanical accommodation variables measured during weighted walking

Carrying weight while walking is a common activity associated with increased musculoskeletal loading, but not all individuals accommodate to the weight in the same way. Different accommodation strategies could lead to different skeletal forces, stimuli for bone adaptation and ultimately bone competence. The purpose of the study was to explore the relationships between calcaneal bone competence and biomechanical accommodation variables measured during weighted walking. Twenty healthy men and women (10 each; age 27.8 ± 6.8 years) walked on a treadmill at 1.34 m/s while carrying 0, 44.5 and 89 N weights with two hands in front of the body. Peak vertical ground reaction force and sagittal plane angular displacements of the trunk and left lower extremity during weight acceptance were measured and used to quantify accommodation. Calcaneal bone stiffness index T-score (BST) was measured using quantitative ultrasound. Correlation and stepwise multiple regression were used to predict calcaneal BST from the accommodation variables. Accommodations of the foot and ankle explained 29 and 54% (p ≤ .015) of the variance in calcaneal BST in different regression models. Statistical resampling using 1000 replications confirmed the strength and consistency of relationships, with the best model explaining 94% of the variance in calcaneal BST. Individuals who change foot and ankle function when carrying heavier weight likely alter the control of gravitational and muscular forces, thereby affecting calcaneal loading, bone adaptation and bone competence. These novel findings illustrate the importance of gait accommodation strategies and highlight a potential clinical consequence that requires further investigation.     

Using accelerator pedal force to increase seat belt use of service vehicle drivers

This study evaluated a device that applied a sustained increase in accelerator pedal back force whenever drivers exceeded a preset speed criterion without buckling their seat belts. This force was removed once the belt was fastened. Participants were 6 commercial drivers who operated carpet-cleaning vans. During baseline, no contingency was in place for unbuckled trips. The pedal resistance was introduced via a multiple baseline design across groups. On the first day of treatment, the device was explained and demonstrated for all drivers of the vehicle. The treatment was associated with an immediate sustained increase in seat belt compliance to 100%. Occasionally, drivers initially did not buckle during a trip and encountered the force. In all instances, they buckled within less than 25 s. These results suggest that the increased force was sufficient to set up an establishing operation to reinforce seat belt buckling negatively. Drivers indicated that they were impressed with the device and would not drive very long unbelted with the pedal force in place.     

Leibniz and Clarke in Conflict: The Role of “Force” and the Nature of God’s Providence

The intellectual background of the concept of force in the dispute between Leibniz and Clarke has not received enough scholarly attention. Vailati’s monograph, which is the most important study of the Leibniz-Clarke correspondence, focuses on a non-theological dimension in terms of the concept of force in this debate. Based on this perspective, Vailati’s conclusion is that Clarke’s understanding of force was totally different from that of Newton. However, the historical context shows that this is not the case. Clarke’s concept of motive force bore a strong resemblance to that of Newton, according to which force was an active principle that had been endowed upon matter at the beginning of God’s creation. Furthermore, the close link between force, matter and God’s providence had a long tradition of debate between Cartesian and Gassendian philosophers since early modern times. The different concepts of force dividing Cartesian and Gassendian philosophers were actually related to, and conditioned by, their underlying fundamental theological differences. The concept of force in the Leibniz-Clarke controversy, accordingly, could be regarded as along the lines of the earlier disputes between Cartesian and Gassendian philosophers.     

Effects of differing response-force requirements on food-maintained responding in CD-1 mice

The effect of force requirements on response effort was examined using outbred (CD-1) mice trained to press a disk with their snout. Lateral peak forces greater than 2 g were defined as threshold responses (i.e., all measured responses). Different force requirements were used to define criterion responses (a subclass of threshold responses) that exceeded the requirement. The reinforcer was sweetened, condensed milk, and it was delivered upon response termination. All mice were exposed to two ascending series of criterion force requirements (2, 4, 8, 16, and 32 g). Increasing the force requirement decreased criterion response rates, but increased threshold response rates. The time-integral of force (area under the force-time curve for individual responses, which is proportional to energy expenditure for each response) increased with the increase in the force requirement. These results conflict with the hypothesis that higher force requirements have aversive qualities and suggest that increased force requirements are more analogous to intermittent schedules of reinforcement. These data suggest that estimations of effort or energy expenditure should be measured independently of the force requirement. Individual differences in responding were found for the CD-1 outbred stock.     

God as Spirit—and Natural Science

The biblical sentence "God is Spirit" (John 4:24) occasioned the development of the Christian doctrine about God as Spirit. But since patristic times "spirit" was interpreted in the sense of Nus, which rather means "intellect." The biblical concept of spirit (pneuma), however, has its root meaning in referring to "air in movement," as in breath or storm. The similar concept of pneuma in Stoic philosophy has become the "immediate precursor" (Max Jammer) of the field concept in modern physics, so that the conclusion is suggested that God is spirit as something like a field of force rather than as intellect. This essay argues for such a conception by relating the divine eternity and immensity to the concepts of space and time, the basic requirements of any physical field. God's eternity and immensity are interpreted in terms of undivided infinite space (and time) which is presupposed in all concepts of parts of space or time (or space-time), therefore in all mathematical and physical measurement.     

Making life easier with effort: Basic findings and applied research on response effort

Early basic research showed that increases in required response effort (or force) produced effects that resembled those produced by punishment. A recent study by Alling and Poling determined some subtle differences between the two behavior-change strategies, but also confirmed that increasing required effort is an effective response-reduction procedure with enduring effects. In this paper we summarize basic research on response effort and explore the role of effort in diverse applied areas including deceleration of aberrant behavior, attention deficit hyperactivity disorder, oral habits, health care appointment keeping, littering, indexes of functional disability, and problem solving. We conclude that renewed interest in response effort as an independent variable is justified because of its potent effects and because the political constraints imposed on punishment- and reinforcement-based procedures have yet to be imposed on procedures that entail manipulations of response effort.     

Jeopardy Not Bonus Status for African American Women in the Work Force: Why Does the Myth of Advantage Persist?

African American women in the United States have a long history of employment outside of their homes. Their experiences are unique from other groups of majority and minority men and women due to the interaction of race, gender, and class. Despite long-standing and continuing struggles against discrimination, harassment, low pay, tokenism, and stereotypes, a myth that African American women enjoy a bonus or advantaged status in the work force has developed and persisted. In this article, Black women's work force experiences are examined from a social constructionist framework, misperceptions of Black women are critiqued, explanations are developed that explain the unique status of African American women and recommendations are proposed to eradicate the discrimination and marginal status that Black women have endured in the work force.     

May the force be with you

This paper is a critical assessment of argumentum ad baculum, or appeal to force. Its principal contention is that, contrary to common opinion, there is no general fallacy of ad baculum. Most real-life ad baculums are, in fact, fairly strong. A basic logical form for reconstructed ad baculums is proposed, and a number of heterodoxical conclusions are also advanced and argued for. They include that ad baculum is not necessarily a prudential argument, that ad baculum need not involve force, violence, or threats, and that one can argue ad baculum to oneself. The starting point of the paper, however, is a critical evaluation of three ad baculums from the exercise sets of Irving Copi's well-known Introduction to Logic.     

Confirmation of linear system theory prediction: Rate of change of Herrnstein's kappa as a function of response-force requirement

Four human subjects worked on all combinations of five variable-interval schedules and five reinforcer magnitudes (¢/reinforcer) in each of two phases of the experiment. In one phase the force requirement on the operandum was low (1 or 11 N) and in the other it was high (25 or 146 N). Estimates of Herrnstein's κ were obtained at each reinforcer magnitude. The results were: (1) response rate was more sensitive to changes in reinforcement rate at the high than at the low force requirement, (2) κ increased from the beginning to the end of the magnitude range for all subjects at both force requirements, (3) the reciprocal of κ was a linear function of the reciprocal of reinforcer magnitude for seven of the eight data sets, and (4) the rate of change of κ was greater at the high than at the low force requirement by an order of magnitude or more. The second and third findings confirm predictions made by linear system theory, and replicate the results of an earlier experiment (McDowell & Wood, 1984). The fourth finding confirms a further prediction of the theory and supports the theory's interpretation of conflicting data on the constancy of Herrnstein's κ.