Psychology

Traditionally, behavioral analysts have termed response strength as the organisms behavior state that is exhibited in various measures among them the rate, latency, the responding force and probability given varying contexts such as experimental context, deprivation context and reinforcement history. According to this concept, elevated response strength is exhibited by increased response rates or greater responses magnitude or shorter latency. However, Nevin, Atak and Mandell have so far challenged or refuted this conception arguing that some measures used including response rates are just variables of schedules of reinforcement and that they are amenable to specific training circumstances. Using low rate behaviors differential reinforcement for example, organisms can be taught or trained pacing their own responses as per the experimenters designed criteria. Nevin and his colleagues came up with a proposition for using resistance to change response as the correct one to measure the strength of response. In the year 2000, Nevin and grace gave an illustrative example using a wall (Domjan, 2009). They argued that a walls strength is not measured by its width, height or other of its dimensions but rather by the weight load amount it is able to withstand while under tests. Also, with all other factors being equal, reinforced concrete walls by rods of steel tends to be more stronger than other similar walls that are not reinforced with steel rods. According to Nevin, Mandell  Atak (1983, in the context of an organisms behavior, learning is considered not merely on how it performs while in a training setting or the classroom settings. What is more important is its performance while subjected to environmental contingencies that have been altered. Performances under the latter setting are said to be resistant to changes in the environment (Nevin, Mandel,  Atak, 1983).

Despite the fact that most behavioral analysts highly support the use of behavioral resistance to change as the effective tool for measuring the response strength, there has been debates on whether greater response strength can be produced by subjecting organisms to environmental circumstances. In the past, schedules of partial reinforcement were thought to be suitable for production of environmental changes resistant behaviors such as extinction by behaviorists. Actually, most of the books relating to or advocating for the use of reinforcement schedules for clinical purposes recommends that while imparting or coming up with a new behavior or skill, a person should first begin by reinforcing all the responses and at time carry out response approximations. With increasing proficiency of a learner, these behaviorists recommend the thinning out of the reinforcement to ensure that not all responses are reinforced but only some deemed vital or essential. This concept is known as PREE or the partial reinforcement extinction effect.

Nevin, 1992 proposed a different hypothesis on partial reinforcement extinction effect (Domjan, 2009). Although this was demonstrated empirically, Nevin came up with the hypothesis that resistance to change of a response is positively related to reinforcement density rate which is associated with a particular behavior. This means that responses that receive higher rates of reinforcement have greater resistance to change as compared to those that receive lower rates of responses after application of behavioral disruptor. This notion is conceptualized in the later behavioral momentum metaphor of Nevin (Nevin  Grace, 2000 found in Domjan, 2009).

There are evident implications of the behavioral momentum model one is the application of reinforcement fading procedure that moves from schedules of continuous reinforcement to schedules of partial reinforcement. This may increase the chances of occurrence of a relapse following changes in conditions from initial training to maintenance. The other implication is that an environment that is highly reinforcing may become counter productive especially when a behavioral therapist tries to reduce a behavior that is challenging. According to Nevin and Grace, behavior rate may decrease if there is an increase in persistence.

Statement of the problem
While employing the behavioral therapy, the various procedures that entail environmental enrichment may become more productive if the theory of behavioral momentum prediction can become more accurate and reliable through elimination of the discrepancies and conflicting findings.

Background of the study
Behavioral momentum metaphor concept was devised by John Nevin in the year 1992 (Domjan, 2009). Nevin who has a PHD psychology and has also studied engineering combined these two disciplines and came up with an operant behavior which he referred to as behavioral momentum. Behavioral momentum refers to a theory of behavior that entails quantitative analysis and it is also a comparative metaphor founded on physical momentum. This theory basically describes the relationship between rate of reinforcement produced on different situations and resistant to change. The momentum concept is derived from response rate produced by reinforcement schedules combination with behavioral dynamic relating to change resistance, two vital dimensions relating to operant behavior as well as analogous to physics mass and velocity. In situations whereby the rate of response that corresponds to velocity is constant or steady under unvarying conditions, combined with the notions that it is difficult to implement changes despite changes in schedules indicates some amount of momentum. On the other hand, behaviors that are change resistant while exposed to stimulus conditions present in reinforcement correlates to the mass concept in physics. As such, behavioral momentum can be used to refer to a behavior that persists even when exposed to certain stimulus despite factors of disruption being employed. Rates of response reduces slowly relative to the level of the baseline where a signal of reinforcement with higher densities is present than in reinforcements of low density (Nevin, Mandel,  Atak, 1983).

In the year 1938, skinner came up with the proposal that discriminated operant was the main fundamental unit of describing behavior. Discriminated operant also referred to as three term contingency is then divided into 3 vital components namely punishing or reinforcing consequence, a response and an antecedent discriminative stimulus context. Responding only occurs if there is a stimulus mainly because previous responses results in consequences in the presence of a stimulus (Honig,  Staddon, 1977).

According to the theory of behavioral momentum, discriminated operant has two aspects that are separable and that govern independently the rate of occurrence of behavior response as well as the response behavior persistence in the light of operant disruption punishment (Nevin  Grace, 2000 contained in Domjan, 2009). The reinforcement contingency of an operant between the reinforcing consequence and the response usually governs or controls the rate of response, that is, the matching law. Matching law refers to a quantitative association that exists between relative reinforcement rates and relative response rates in reinforcement schedules that are concurrent. It is more suitable and reliable for subjects that are non human when they are subjected to interval schedules that are concurrently variable. The applicability of the operant conditioning is less clear in various situations and this largely depends on the different assumptions made as well as the experimental situation details (Honig,  Staddon, 1977). Pavlovian relation that exists between the rates of obtained reinforcement as a result of discriminative stimulus presence in a contextual environment and the discriminative stimulus context environment dictates the resistance behavior in relation to change or the process of extinction of a pattern of response behavior. Change behavior resistance is evaluated as a conditional response in conditions of environmental stimulus response disruption such as extinction or satiation, in the light of stable and pre-disruption rates of response to behavior (Honig,  Staddon, 1977).

Skinner also contributed to the understanding of the way animals learn. He developed the skinner box also referred to as the operant chamber as a means of measuring behavior of animals that were freely moving, reinforcement schedules which are rules that specify when and how animals ought to behave for reinforcement to take place and also a graphical presentation of recording all operant responses. There are two reinforcement schedules in use today the interval schedules and ration schedules. While using interval schedules, first responses following the elapsing of unsignaled predetermined interval are usually rewarded. The duration of an interval is usually fixed or may be drawn randomly from distributions having certain mean. Interval sequence can also be determined using rules of, varying periodically, descending or ascending. While generating distributions with exponential distribution that are memoryless, such a schedule is referred to as variable interval or random interval schedule. In experimental sessions, the first interval is usually timed from its commencement to the end while other interval experiments carried out later are timed based on the preceding rewards. Ratio schedules reinforcement is the second type of schedule in use today. It is given after the emission of a number of actions. Number of responses required can either be fixed or obtained from a distribution randomly. The labeling of schedules is done based on their types as well as the parameter of the schedule (Nevin, Mandel,  Atak, 1983).

Resistance to disruption is viewed as the most superior or better measure of response rates that are stable in the response underlying strength expression. The reasons for this is due to the fact that response rates can be as a result of shaping of some behavior patterns by reinforcement contingency for example differential reinforcement of either low or high schedules of response rates, in situations where rates of reinforcement are equal. However, it is not clear whether such response rates differences indicate differences in a responses underlying strength (Zeiler  Harzem, 1979).

According to the theory of behavioral momentum, the relationship that exists between change resistance and rates of response is analogous to mass and velocity of any moving object and it is founded on the second law of motion devised or developed by Newton. The Newtons laws of motion is made up of 3 physical laws which lay the foundation for classical mechanics. These laws are at a state of net force absence, a body can only be resting or if moving, it can only do so following a straight line with its speed being constant. The second law states that a body that is experiencing or subjected to a force (F), experiences a related acceleration (a) that is related to the force. Fma with m being the bodys mass. This means that momentum of time derivative is equal to the force. The third law states that following exertion of a force by 1st body on a 2nd body, the latter body exerts a negative force (-F) on the former body. As such, -F and F have magnitudes that are equal with their directions being opposite (Nevin, Mandel,  Atak, 1983). The three physical laws give a description of the relationship existing between body motion and forces exerted on a body and they were developed by Isaac Newton in the 17th century. The second law in the law of motion that states that velocity changes in moving bodies or objects following the exertion or application of outside force tends to be directly related to the applied force and in turn inversely related to the body mass of the object. The theory of behavioral momentum is closely linked to this theory as it states that changes in the rates of response under disruptions conditions, expressed as Bx, and comparative to baseline rates of response, expressed as Bo tend to be directly related to the magnitude or the disruption force, denoted as f and also inversely correlated to reinforcement rate in a context of stimulus denoted as r. as such, log (BxBo)  - (fr (raised to power b)) (Domjan, 2009). B is a free parameter indicating the change resistance sensitivity to reinforcement rates in the context of a stimulus, that is, the stimulus-reinforcer relation (Domjan, 2009). Disruption resistance is basically assessed only when alternate stimulus contexts are distinctively discriminative and have differing reinforcement schedules signals.

Consistency has been observed with the theory on behavioral momentum in regard to disruption resistance. It has been found out that greater disruption resistance is experienced in stimulus contexts that have higher reinforcement magnitudes or rates. Much of the strong support of change resistance as  being influenced by relations of stimulus reinforcer as well s relations of independent response reinforcer emanates from various studies that combine or add reinforcement that is response independent to a single stimulus context.

Research questions
The paper seeks to answer the following research questions
Can the partial reinforcement extinction effect prediction be confirmed using interval schedules that are variable under contexts of free operant
Can behavioral momentum metaphor predictions be confirmed using a paradigm of restricted operant
Measures and procedures

Various studies have been carried out so far relating to behavioral momentum and PREE effect. In the year 1992, Nevin et al conducted a study using pigeons to assess their behavior based on operant conditioning. The study had pigeons that were pecking on some lighted disks on several variable interval separated by 60 seconds schedules of reinforcement with intermittent food across a multiple schedule of two components. After ever fifteen to thirty seconds, free reinforcers were added or presented only when the disk turned red but when it was green, no reinforcers were presented. Thus, the relation of response reinforcer became degraded or reduced when disk turned red since each reinforcer did not have immediate preceding response. Rates of response were much lower in the context of red as compared to the green context and this was consistence to the matching law. However, the relation of stimulus reinforcer was improved in the context of red disk since the collective good presentation rate was much greater. This was found to be in line with the theory of behavioral momentum which states that presession feeding resistance or satiation and reinforcement discontinuation in the green and red contexts or the extinctions was much greater in the context of red than in green context. Such results have been evident in cases where reinforcers are increased to one context via reinforcing the other alternative response.

This study and findings obtained by Nevin and his colleagues have been expanded across several species and procedures such as the gold fish study, on rats (several behavioral analysts have used rats), on pigeons and on human beings by several behavioral analysts. The framework of behavioral momentum has also been to explain the concept of partial reinforcement extinction effect by Nevin and Grace, in assessing the behavior persistence in relation to drugs as well as burke and Shahan, in increasing compliance to task and in understanding the social policies effects on global problems by Nevin.
Since disruption resistance while using different stimulus contexts happens to be analogous to moving objects inertial mass, the theory of behavioral momentum also argues that preference in procedures relating to concurrent chains relating to one stimulus context responding to initial links that are concurrently available offers access or leeway to one of those two stimulus contexts that are mutually exclusive. Just like in the case of multiple schedules, reinforcements of independent schedules have the capacity of functioning in terminal link context. The response of relative allocation in two links show how far an organism chooses or prefers to follow one terminal context link as compared to the other link. The theory of behavioral momentum also argues that preference of an organism to some stimulus offers a measure of the value of conditioned reinforcement over two contexts of terminal links.

Despite the fact that the theory of behavioral momentum offers a powerful framework of gaining a better understanding on reinforcement context and how this concept affects discriminated operant behavior persistence, several conflicting findings that are not consistent with this theory have been obtained. One of the examples is seen when equal rates of reinforcements are employed in different stimulus contexts. In such scenarios, manipulating the relations of response reinforcer has been found to affect change resistance while some schedules have been found to produce varying baseline rates of response. Also, reinforcement delays have been observed while employing the theory of behavioral momentum and introducing brief stimuli together with reinforcement also has led to delays in reinforcement. It is also not clear as to what factors have effects of change resistance while conditioned reinforcement is maintained.

Conclusion
Behavioral analysts have been studying the behavior of organisms hoping to establish patterns that can be used for clinical purposes. The theory of behavioral momentum is one of the most widely used today. Despite the fact that it has shown or proved to be reliable in most non human organisms that have been used during study such as the pigeon and rats, its effects or reliability as a therapy tool on human beings. Other studies are underway to assess the reliability of this theory and various modifications have been made so far to this theory to increase its reliability.