bluuebunny/crossref_metadata_2025 huggingface dataset:
SPECTRAL AND PATTERN RESPONSE IN THE RABBIT RETINA
Authors: Armington John C. , Adolph Alan R.
Published: March 2006

The advantages of presenting sensory data in terms of stimulus variables are stressed. Spectral sensitivity plots of local electroretinograms and ganglion cell discharges from the dark‐adapted rabbit retina illustrate the utility of using this kind of procedure. Spectral data agreed with the literature demonstrating two cone and one rod process in this animal. The spectral sensitivities of both the local electroretinogram and ganglion cell spikes were closely similar. Data pertaining to pattern vision may also be subjected to the same type of analysis and described in terms of stimulus variables.
BEHAVIOR ANALYSIS AND THE SEARCH FOR THE ORIGINS OF HYPERTENSION
Authors: Anderson David E.
Published: March 2006

Hypertension is a disorder of sodium regulation that develops over time in a context of the interactions of the individual with the environment. Experimental hypertension can be induced in laboratory animals and normotensive humans via increases in sodium intake under conditions of aversive behavioral control. Readiness for avoidance contingencies includes a breathing pattern characterized by subnormal rate and normal tidal volume. Studies with humans have shown that this inhibitory breathing pattern is associated with increased plasma acidity, increased renal sodium reabsorption, increased secretion of digitalis‐like hormones that inhibit sodium‐pump activity, and increased vasoconstriction and blood pressure. Behavioral research is needed that defines the necessary and sufficient conditions for inhibitory breathing and its role in the development of hypertension.
STABILITY OF VISCERAL BEHAVIOR IN THE AWAKE RAT DURING REST
Authors: Randall David C. , Brown David R.
Published: March 2006

Brady and colleagues have championed the importance of careful delineation and control of a subject's behavioral state. In this paper we develop the concept of visceral behavior from a physiological perspective. Sprague‐Dawley rats were instrumented to record arterial blood pressure, renal sympathetic nerve activity, and respiration. The rats were restrained in a conical cloth sock. Rats that were well adapted to the sock restraint showed a regular respiratory pattern and consistent pressure recordings; they rested quietly in the sock and moved only occasionally to adjust their position. Fourier analysis of blood pressure and nerve activity showed a concentration of power below 1 Hz. The coherence between the two signals was strong (0.83 ± 0.03) at 0.42 Hz. Conversely, during their initial adjustment to the sock restraint, the rats tended to show large fluctuations in blood pressure associated with episodic apneic breathing; 1 animal displayed this pattern of visceral behavior throughout most of the experiment. Despite this instability in pressure, the rats' overt behavior was stable: They rested quietly in the sock with only occasional position shifts. Spectral analysis and coherence computations showed large shifts in the distribution of power and frequency range over which arterial pressure and sympathetic activity were tightly coupled. These data are consistent with the view that an animal's circulatory adjustments, as well as adjustments in other aspects of its physiological state, constitute an important aspect of behavior, and that this behavior can influence the interpretation of biobehavioral data.
DESIGNING A BEHAVIORAL PROGRAM FOR A BARRIO IN TEGUCIGALPA, HONDURAS
Authors: Cohen Harold L.
Published: March 2006

Health in Housing initiated a behavioral program of education and skills training for children and adults in a community of 30,000 persons living in substandard conditions in Tegucigalpa, Honduras. To measure achievement in the long‐range project, 21 families of Flor del Campo participated in a preliminary three‐part survey of their (a) health, (b) housing and the environment, and (c) family history. Doctors, designers, and educators worked with Honduran personnel in the first survey. Following functional analyses of the home and surrounding environment and the physical status of the individuals living there, procedures provide the family with treatment and training for home and environment improvement. Graphic, verbal, and numerical data, incorporated into a master computerized system, record events of each family member: training programs experienced, health care delivery courses taken, medical treatments, growth of children, literacy changes, educational courses completed, kinds and amounts of foods eaten, household and building materials purchased. Ongoing functional analysis and a long‐range evaluation are made of the progress of each participating individual in a family. Teams revisit each house to observe and record any changes in the physical and environmental facility and the health and life‐styles, and to report any indications of new health problems or recurrences.
THE RELATIONS BETWEEN NEUROSCIENCE AND HUMAN BEHAVIORAL SCIENCE
Authors: Strumwasser Felix
Published: March 2006

Neuroscience seeks to understand how the human brain, perhaps the most complex electrochemical machine in the universe, works, in terms of molecules, membranes, cells and cell assemblies, development, plasticity, learning, memory, cognition, and behavior. The human behavioral sciences, in particular psychiatry and clinical psychology, deal with disorders of human behavior and mentation. The gap between neuroscience and the human behavioral sciences is still large. However, some major advances in neuroscience over the last two decades have diminished the span. This article reviews the major advances of neuroscience in six areas with relevance to the behavioral sciences: (a) evolution of the nervous system; (b) visualizing activity in the human brain; (c) plasticity of the cerebral cortex; (d) receptors, ion channels, and second/third messengers; (e) molecular genetic approaches; and (f) understanding integrative systems with networks and circadian clocks as examples.
EFFECTS OF REINFORCEMENT HISTORY ON RESPONDING UNDER PROGRESSIVE‐RATIO SCHEDULES OF REINFORCEMENT
Authors: Cohen Steven L. , Pedersen Jennifer , Kinney Gene G. , Myers James
Published: March 2006

The effects of experimental history on responding under a progressive‐ratio schedule of reinforcement were examined. Sixteen pigeons were divided into four equal groups. Groups 1 to 3 were trained to peck a key for food under a fixed‐ratio, variable‐ratio, or differential‐reinforcement‐of‐low‐rate schedule of reinforcement. After training, these pigeons were shifted to a progressive‐ratio schedule, later were shifted back to their original schedule (with decreased rates of reinforcement), and finally were returned to the progressive‐ratio schedule. Pigeons in Group 4 (control) were maintained on the progressive‐ratio schedule for the entire experiment. To test for potential “latent history” effects, pigeons responding under the progressive‐ratio schedule were injected with d‐amphetamine and given behavioral‐momentum tests of prefeeding and extinction. Experimental histories affected responding in the immediate transition to the progressive‐ratio schedule; response rates of pigeons with variable‐ratio and fixed‐ratio histories were higher than rates of pigeons with differential‐reinforcement‐of‐low‐rate and progressive‐ratio‐only histories. Pigeons with differential‐reinforcement‐of‐low‐rate histories, and to a lesser degree pigeons with variable‐ratio and fixed‐ratio histories, also had shorter postreinforcement pauses than pigeons with only a progressive‐ratio history. No consistent long‐term effects of prior contingencies on responding under the progressive‐ratio schedule were evident. d‐Amphetamine and resistance‐to‐change tests failed to reveal consistent latent history effects. The data suggest that history effects are sometimes transitory and not susceptible to latent influences.
AN INVESTIGATION OF THE DIFFERENTIAL‐OUTCOMES EFFECT WITHIN SESSIONS
Authors: Jones B. Maxwell , White K. Geoffrey
Published: March 2006

The differential‐outcomes effect is manifest as more accurate performance of a delayed conditional discrimination when alternative choice responses are followed by different reinforcers than when they are followed by the same reinforcer. In Experiment 1, a differential‐outcomes effect was demonstrated within sessions by signaling the duration of food access for correct responses with stimuli appearing in conjunction with the sample stimuli. The delayed matching‐to‐sample performance of 5 pigeons was more accurate when green choice responses (matching a green sample) were followed by 3.5‐s food access and red choice responses (matching a red sample) were followed by 0.5‐s food access (different‐outcome trials) than when the correct choice responses were both followed by 1.5‐s reinforcers (same‐outcome trials). In Experiment 2, the acquisition of this differential‐outcomes effect was characterized by a progressive decrease in rate of forgetting on different‐outcome trials and no change in rate of forgetting on same‐outcome trials. In addition, accuracy at the shortest delay intervals for both different‐outcome and same‐outcome trials increased over acquisition, but to a greater extent for different‐outcome trials. These data suggest that both memorial and attentional (time‐dependent and time‐independent) factors contribute to the differential‐outcomes effect.
CONTRAST AND UNDERMATCHING WITH REGULAR OR IRREGULAR ALTERNATION OF COMPONENTS
Authors: McLean Anthony P. , Morritt Carole F.
Published: March 2006

Behavioral contrast and response‐ratio sensitivity to reinforcement were compared in multiple schedules in which components alternated strictly or according to a pseudorandom sequence. Average component durations in the two regimes were always 60 s, and order of presentation of component alternation regimes was counterbalanced across subjects. In Part 1, the reinforcer rate in one component was reduced from 60 per hour to zero, while that in the other component was unchanged. Positive behavioral contrast occurred in the constant component in that response rates increased, but neither the reliability nor the magnitude of contrast was affected by the manner in which components alternated. Part 2 was similar, except that a number of different reinforcer rates were used in the varied component. Neither contrast nor sensitivity of response ratios to changes in reinforcer ratios depended on the regime of component alternation. Thus, the predictability in time of future reinforcement conditions, which is a feature of regular multiple scheduling, does not appear to be a determinant of multiple‐schedule performance.
BRIEF‐STIMULUS PRESENTATIONS ON MULTIFORM TANDEM SCHEDULES
Authors: Reed Phil
Published: March 2006

Three experiments examined the influence of a brief stimulus (a light) on the behavior of food‐deprived rats whose lever pressing on tandem schedules comprising components of different schedule types resulted in food presentation. In Experiment 1, either a tandem variable‐ratio variable‐interval or a tandem variable‐interval variable‐ratio schedule was used. The variable‐interval requirement in the tandem variable‐ratio variable‐interval schedule was yoked to the time taken to complete the variable‐ratio component in the tandem variable‐interval variable‐ratio schedule, and the length of the variable‐interval component in the latter schedule was yoked to the variable‐ratio component in the former schedule. If a brief stimulus occurred following completion of the first component, then behavior was differentiated in the two components; subjects responded more quickly in the variable‐ratio than in the variable‐interval component. If the stimulus was removed, then response rate was determined by the nature of the final component. Similar results were obtained in Experiments 2 and 3 with the use of a three‐component tandem variable‐ratio variable‐interval variable‐ratio schedule or tandem variable‐interval variable‐ratio variable‐interval schedule. Thus, a brief stimulus that was not explicitly paired with reinforcement engendered behavior typical of the component schedule preceding its presentation.
RESPONSE‐RATE DIFFERENCES IN VARIABLE‐INTERVAL AND VARIABLE‐RATIO SCHEDULES: AN OLD PROBLEM REVISITED
Authors: Cole Mark R.
Published: March 2006

In Experiment 1, a variable‐ratio 10 schedule became, successively, a variable‐interval schedule with only the minimum interreinforcement intervals yoked to the variable ratio, or a variable‐interval schedule with both interreinforcement intervals and reinforced interresponse times yoked to the variable ratio. Response rates in the variable‐interval schedule with both interreinforcement interval and reinforced interresponse time yoking fell between the higher rates maintained by the variable‐ratio schedule and the lower rates maintained by the variable‐interval schedule with only interreinforcement interval yoking. In Experiment 2, a tandem variable‐interval 15‐s variable‐ratio 5 schedule became a yoked tandem variable‐ratio 5 variable‐interval x‐s schedule, and a tandem variable‐interval 30‐s variable‐ratio 10 schedule became a yoked tandem variable‐ratio 10 variable‐interval x‐s schedule. In the yoked tandem schedules, the minimum interreinforcement intervals in the variable‐interval components were those that equated overall interreinforcement times in the two phases. Response rates did not decline in the yoked schedules even when the reinforced interresponse times became longer. Experiment 1 suggests that both reinforced interresponse times and response rate‐reinforcement rate correlations determine response‐rate differences in variable‐ratio 10 and yoked variable‐interval schedules in rats. Experiment 2 suggests a minimal role for the reinforced interresponse time in determining response rates on tandem variable‐interval 30‐s variable‐ratio 10 and yoked tandem variable‐ratio 10 variable‐interval x‐s schedules in rats.
HUMAN CHOICE IN CONCURRENT RATIO‐INTERVAL SCHEDULES OF REINFORCEMENT
Authors: Savastano Hernán I. , Fantino Edmund
Published: March 2006

Seven undergraduates participated in a concurrent‐choice experiment with monetary reinforcers. Response‐independent analogues of variable‐interval and variable‐ratio schedules were used to assess whether subjects would maximize reinforcement rate. The optimal pattern of behavior, in terms of maximizing reinforcement rate, involved a large bias toward the ratio alternative, with only occasional sampling of the interval schedule. Most experiments with pigeons, however, demonstrate matching of response rates to reinforcement rates, with only slight biases for the ratio schedule. Although subjects in the present experiment allocated more time to the ratio alternative than required by matching, the magnitude of the bias did not approximate that predicted by a maximizing account. After exposure to clock stimuli correlated with the operation of each schedule, 1 subject's behavior did show a substantial level of bias, increasing the total number of reinforcers obtained, and lay at a point between the predictions of matching and maximizing. The other subjects, however, continued to respond less optimally. The present results can be accounted for by a view of matching that incorporates the effects of delayed reinforcement.
REIN FORCER MAGNITUDE (SUCROSE CONCENTRATION) AND THE MATCHING LAW THEORY OF RESPONSE STRENGTH
Authors: Heyman Gene M. , Monaghan Michael M.
Published: March 2006

This experiment investigated the relationship between reinforcer magnitude (sucrose concentration) and response rate. The purpose was to evaluate the behavior of two parameters of an equation that predicts absolute response rate as a function of reinforcement rate and two free parameters. According to Herrnstein's (1970) theory of reinforced behavior, one parameter of this “response‐strength equation” measures the efficacy of the reinforcer maintaining responding and the other parameter measures motoric components of response rate, such as response duration. Seven rats served as subjects. Experimental sessions consisted of a series of five different variable‐interval schedules of reinforcement, each in effect for 5 minutes. Within each session, obtained reinforcement rates varied over more than a 30‐fold range, from about 20 per hour to 700 per hour. The reinforcer was sucrose solution, and, between sessions, its concentration was varied from 0.0 to 0.64 molar (0 to 21.9%). For sucrose concentrations of 0.16 to 0.64 m, response rate was a negatively accelerated function of reinforcement rate. Increases in sucrose concentration increased response rates maintained by low but not high reinforcement rates. This pattern of changes corresponds to a change in the reinforcement‐efficacy parameter of the response‐strength equation. In contrast, the motor‐performance parameter did not change as a function of sucrose concentration. These findings are inconsistent with the results of a similar study (Bradshaw, Szabadi, & Bevan, 1978) but support Herrnstein's theory of reinforced behavior.
BASIC RESEARCH NEEDED FOR STIMULATING THE DEVELOPMENT OF BEHAVIORAL TECHNOLOGIES
Authors: Mace F. Charles
Published: March 2006

The costs of disconnection between the basic and applied sectors of behavior analysis are reviewed, and some solutions to these problems are proposed. Central to these solutions are collaborations between basic and applied behavioral scientists in programmatic research that addresses the behavioral basis and solution of human behavior problems. This kind of collaboration parallels the deliberate interactions between basic and applied researchers that have proven to be so profitable in other scientific fields, such as medicine. Basic research questions of particular relevance to the development of behavioral technologies are posed in the following areas: response allocation, resistance to change, countercontrol, formation and differentiation/discrimination of stimulus and response classes, analysis of low‐rate behavior, and rule‐governed behavior. Three interrelated strategies to build connections between the basic and applied analysis of behavior are identified: (a) the development of nonhuman animal models of human behavior problems using operations that parallel plausible human circumstances, (b) replication of the modeled relations with human subjects in the operant laboratory, and (c) tests of the generality of the model with actual human problems in natural settings.
AUTOSHAPING THE PIGEON'S GAPE RESPONSE: ACQUISITION AND TOPOGRAPHY AS A FUNCTION OF REINFORCER TYPE AND MAGNITUDE
Authors: Allan Robert W. , Zeigler H. Philip
Published: March 2006

The pigeon's key‐pecking response is experimentally dissociable into transport (head movement) and gape (jaw movement) components. During conditioning of the key‐pecking response, both components come under the control of the conditioned stimulus. To study the acquisition of gape conditioned responses and to clarify the contribution of unconditioned stimulus (reinforcer) variables to the form of the response, gape and key‐contact responses were recorded during an autoshaping procedure and reinforcer properties were systematically varied. One group of 8 pigeons was food deprived and subgroups of 2 birds each were exposed to four different pellet sizes as reinforcers, each reinforcer signaled by a keylight conditioned stimulus. A second group was water deprived and received water reinforcers paired with the conditioned stimulus. Water‐ or food‐deprived control groups received appropriate water or food reinforcers that were randomly delivered with respect to the keylight stimulus. Acquisition of the conditioned gape response frequently preceded key‐contact responses, and gape conditioned responses were generally elicited at higher rates than were key contacts. The form of the conditioned gape was similar to, but not identical with, the form of the unconditioned gape. The gape component is a critical topographical feature of the conditioned key peck, a sensitive measure of conditioning during autoshaping, and an important source of the observed similarities in the form of conditioned and consummatory responses.
BIAS IN SELF‐EVALUATION: SIGNAL PROBABILITY EFFECTS
Authors: Critchfield Thomas S.
Published: March 2006

Two experiments examined apparent signal probability effects in simple verbal self‐reports. After each trial of a delayed matching‐to‐sample task, young adults pressed either a “yes” or a “no” button to answer a computer‐presented query about whether the most recent choice met a point contingency requiring both speed and accuracy. A successful matching‐to‐sample choice served as the “signal” in a signal‐detection analysis of self‐reports. Difficulty of matching to sample, and thus signal probability, was manipulated via the number of nonmatching sample and comparison stimuli. In Experiment 1, subjects exhibited a bias (log b) for reporting matching‐to‐sample success when success was frequent, and no bias or a bias for reporting failure when success was infrequent. Contingencies involving equal conditional probabilities of point consequences for “I succeeded” and “I failed” reports had no systematic effect on this pattern. Experiment 2 found signal probability effects to be evident regardless of whether referent‐response difficulty was manipulated in different conditions or within sessions. These findings indicate that apparent signal probability effects in self‐report bias that were observed in previous studies probably were not an artifact of contingencies intended to improve self‐report accuracy or of the means of manipulating signal probability. The findings support an analogy between simple self‐reports and psychophysical judgments and bolster the conclusion of Critchfield (1993) that signal probability effects can influence simple self‐reports much as they do reports about external stimuli in psychophysical experiments.
A TRANSFER OF SELF‐DISCRIMINATION RESPONSE FUNCTIONS THROUGH EQUIVALENCE RELATIONS
Authors: Dymond Simon , Barnes Dermot
Published: March 2006

The present study tested the idea that human self‐discrimination response functions may transfer through equivalence relations. Four subjects were trained in six symbolic matching‐to‐sample tasks (if see A1, choose B1; A1‐C1, A2‐B2, A2‐C2, A3‐B3, A3‐C3) and were then tested for the formation of three equivalence relations (B1‐C1, B2‐C2, B3‐C3). Two of the B stimuli (B1 and B2) were then used to train two different self‐discrimination responses using either detailed instructions (Subjects 1 to 3) or minimal instructions (Subject 4) on two complex schedules of reinforcement (i.e., subjects were trained to pick the B1 stimulus if they had not emitted a response, and to pick the B2 stimulus if they had emitted one or more responses on the previous schedule). All 4 subjects showed the predicted transfer of self‐discrimination response functions through equivalence relations (i.e., no response on the schedule, pick C1; one or more responses on the schedule, pick C2). Subjects also demonstrated this transfer when they were required to discriminate their schedule performance before exposure to the schedule (i.e., “what I intend to do”). Four control subjects were also used in the study. Two of these (Subjects 5 and 6) were not exposed to any form of matching‐to‐sample training and testing (nonequivalence controls). The 2 remaining subjects (7 and 8) were exposed to matching‐to‐sample training and testing that incorporated stimuli not used during the transfer test; C1 and C2 were replaced by N1 and N2 during the matching‐to‐sample training and testing, but C1 and C2 were used for the transfer tests (equivalence controls). All 4 subjects failed to produce the self‐discrimination transfer performances observed with the experimental subjects.
VARYING THE TEMPORAL PLACEMENT OF A DRINKING OPPORTUNITY IN A FIXED‐INTERVAL SCHEDULE
Authors: Raul Avila S. , Bruner Carlos A.
Published: March 2006

Three rats, lever pressing for food delivered on a fixed‐interval 128‐s schedule, were presented with a 16‐s opportunity to drink from a retractable water source. The temporal placement of the water probe within the reinforcement cycle was varied sequentially, in steps of 16 s. Although the lever‐pressing pattern was modulated by the intercalated water probe, water consumption during the probe itself was a decreasing function of time from the following reinforcer. These results were interpreted as evidence against the notion that schedule‐induced drinking is a “ubiquitous” phenomenon and are congruent with results from other “intruded stimulus” experiments.
CHOICE BETWEEN RELIABLE AND UNRELIABLE REINFORCEMENT ALTERNATIVES REVISITED: PREFERENCE FOR UNRELIABLE REINFORCEMENT
Authors: Belke Terry W. , Spetch Marcia L.
Published: March 2006

Pigeons' choices between a reliable alternative that always provided food after a delay (i.e., 100% reinforcement) and an unreliable one that provided food or blackout equally often after a delay (i.e., 50% reinforcement) was studied using a discrete‐trials concurrent‐chains procedure modified to prevent choice between alternatives following a blackout outcome. Initial links were fixed‐ratio 1 schedules, and terminal links were fixed‐time schedules. Stimuli presented during the terminal‐link delays were correlated with the food and blackout outcomes. In Experiment 1, terminal‐link durations were varied. With short terminal links (i.e., 10 s), 6 of 8 subjects showed strong preference for the 50% side. As terminal‐link duration increased to 30 s, preference, regardless of direction, became less extreme. In Experiment 2, the side‐key location of the 50% and 100% alternatives was reversed for 3 subjects. Preference for the 50% alternative reoccurred following the key reversal. When a 5‐s separation was subsequently interposed between the initial and terminal links for both alternatives, all birds reversed to a preference for the 100% side. In general, the strong preference for the 50% side was qualitatively consistent with the expectation that the procedure enhanced the conditioned‐reinforcement effectiveness of the food‐associated terminal‐link stimulus on the 50% side. Implications of the results for various accounts of choice of the 50% alternative are discussed.
INSTRUCTIONAL VERSUS SCHEDULE CONTROL OF HUMANS' CHOICES IN SITUATIONS OF DIMINISHING RETURNS
Authors: Hackenberg Timothy D. , Joker Veronica R.
Published: March 2006

Four adult humans chose repeatedly between a fixed‐time schedule (of points later exchangeable for money) and a progressive‐time schedule that began at 0 s and increased by a fixed number of seconds with each point delivered by that schedule. Each point delivered by the fixed‐time schedule reset the requirements of the progressive‐time schedule to its minimum value. Subjects were provided with instructions that specified a particular sequence of choices. Under the initial conditions, the instructions accurately specified the optimal choice sequence. Thus, control by instructions and optimal control by the programmed contingencies both supported the same performance. To distinguish the effects of instructions from schedule sensitivity, the correspondence between the instructed and optimal choice patterns was gradually altered across conditions by varying the step size of the progressive‐time schedule while maintaining the same instructions. Step size was manipulated, typically in 1‐s units, first in an ascending and then in a descending sequence of conditions. Instructions quickly established control in all 4 subjects but, by narrowing the range of choice patterns, they reduced subsequent sensitivity to schedule changes. Instructional control was maintained across the ascending sequence of progressive‐time values for each subject, but eventually diminished, giving way to more schedule‐appropriate patterns. The transition from instruction‐appropriate to schedule‐appropriate behavior was characterized by an increase in the variability of choice patterns and local increases in point density. On the descending sequence of progressive‐time values, behavior appeared to be schedule sensitive, sometimes even optimally sensitive, but it did not always change systematically with the contingencies, suggesting the involvement of other factors.
CUED AND UNCUED TERMINAL LINKS IN CONCURRENT‐CHAINS SCHEDULES
Authors: Alsop Brent , Stewart Karen E. , Honig Werner K.
Published: March 2006

Pigeons were trained on a concurrent‐chains schedule. The initial links were concurrent variable‐interval schedules arranged on two side keys. Each terminal link was a fixed‐interval schedule arranged on the center key. In cued conditions, different center‐key colors signaled the two terminal‐link schedules. In uncued conditions, the same center‐key color appeared for both terminal links. Experiment 1 arranged unequal initial links and equal terminal links. Preference for the shorter initial‐link schedule was greater when the terminal links were uncued. Experiment 2 arranged equal initial links and unequal terminal links. Preference for the shorter terminal‐link schedule was greater when the terminal links were cued. Although the results of Experiment 2 successfully replicated previous research, the results of Experiment 1 are not easily reconciled with conditioned‐reinforcement or discriminative‐stimulus accounts of the role of terminal‐link cues. Rather, terminal‐link cues appear to decrease sensitivity to initial‐link contingencies.
RATIO VERSUS DIFFERENCE COMPARATORS IN CHOICE
Authors: Gibbon John , Fairhurst Stephen
Published: March 2006

Several theories in the learning literature describe decision rules for performance utilizing ratios and differences. The present paper analyzes rules for choice based on either delays to food, immediacies (the inverse of delays), or rates of food, combined factorially with a ratio or difference comparator. An experiment using the time‐left procedure (Gibbon & Church, 1981) is reported with motivational differentials induced by unequal reinforcement durations. The preference results were compatible with a ratio‐comparator decision rule, but not with decision rules based on differences. Differential reinforcement amounts were functionally equivalent to changes in delays to food. Under biased reinforcement, overall food rate was increased, but variance in preference was increased or decreased depending on which alternative was favored. This is a Weber law finding that is compatible with multiplicative, scalar sources of variance but incompatible with pacemaker rate changes proportional to food presentation rate.
REVERSAL OF BASELINE RELATIONS AND STIMULUS EQUIVALENCE: I. ADULTS
Authors: Pilgrim Carol , Galizio Mark
Published: March 2006

Following the emergence of two four‐member equivalence classes (A1B1C1D1 and A2B2C2D2), 5 students were exposed to a series of phases including a baseline conditional discrimination reversal (i.e., choosing D2 was reinforced and D1 punished given Sample A1; choosing D1 was reinforced and D2 punished given Sample A2), the delayed introduction of CD/DC transitivity/equivalence probes, DE conditional discrimination training, a second baseline conditional discrimination reversal (i.e., choosing C2 was reinforced given B1, etc.), and a return to original baseline reinforcement contingencies. Results showed that baseline and symmetry probe performances were extremely sensitive to baseline modifications. In contrast, patterns on transitivity/equivalence probes remained predominantly consistent with the originally established equivalence classes, although there were exceptions on some E probe relations for 2 subjects. The dissociation between baseline and symmetry versus transitivity/equivalence patterns may have important implications because it is not easily accounted for by current models of equivalence phenomena.
DISCRIMINATIVE STIMULUS EFFECTS OF DIAZEPAM AND BUSPIRONE IN NORMAL VOLUNTEERS
Authors: Rush Craig R. , Critchfield Thomas S. , Troisi Joseph R. , Griffiths Roland R.
Published: March 2006

A within‐subject design was used to characterize the effects of dose manipulations on discriminative and self‐reported effects of oral diazepam and buspirone. Subjects were trained to discriminate diazepam (10 mg) versus placebo (n = 10), or buspirone (10 or 15 mg) versus placebo (n = 9). The compounds were identified to subjects by letter code before discrimination training began. In later sessions, correct identifications at 2 hr after the oral administration of drug earned money. All subjects showed accurate discrimination performance during the test‐of‐acquisition phase. In a low‐dose generalization phase, diazepam and buspirone produced dose‐related increases in drug identifications across a four‐fold range of doses. In a subsequent low‐dose training phase, in which subjects were trained to discriminate progressively lower drug doses, the median lowest discriminable dose of diazepam and buspirone was 2.5 and 7.5 mg, respectively. Dose‐response functions for drug identifications were shifted leftward in the low‐dose training phase relative to the low‐dose generalization phase, suggesting that reinforcement of progressively lower doses enhances drug discriminability. The self‐reported effects of diazepam and buspirone were similar (e.g., both drugs increased ratings of drug strength and clumsy/uncoordinated) and different (e.g., diazepam but not buspirone increased ratings of drowsy/sleepy; buspirone but not diazepam increased ratings of tense/nervous). This study demonstrates discriminative and self‐reported effects of diazepam and buspirone at doses lower than previously shown to be behaviorally active, and suggests that at commonly used clinical doses, diazepam is relatively more discriminable than buspirone.
PROCUREMENT TIME AS A DETERMINANT OF MEAL FREQUENCY AND MEAL DURATION
Authors: Mathis Carl E. , Johnson Deanne F. , Collier George H.
Published: March 2006

Foraging involves the expenditure of both time and effort in the acquisition of food; animals typically modify their meal patterns so as to reduce these expenditures or costs. The contribution of time, as compared with effort, to the overall cost perceived by an animal is not known. We investigated the effect of foraging time as a cost independent of effort by measuring the meal patterns of rats living in a laboratory foraging simulation in which they earned all their daily intake. They pressed a bar once to initiate an interval (procurement interval) leading to the presentation of a large cup of food from which they could eat a meal of any size. As the length of the interval increased from 1 s to 46 hr, meal frequency decreased regularly. Meal size increased in a compensatory fashion, and total daily intake was conserved through an interval of 23 hr. The changes in meal frequency occurred because of changes in the rat's latency to bar press after each meal. The functions relating meal frequency and size to the procurement interval were of the same shape as those seen when cost is the completion of a bar‐press requirement, which entails the expenditure of both effort and time. When the bar‐press requirement was increased to 10, meal frequency was reduced, but time and effort did not appear to simply add together in the rat's perception of cost. These data reveal that time is perceived to be a cost by rats foraging in this laboratory environment. These results suggest that the time parameters of foraging are different from those of consumption.
PRISONER'S DILEMMA AND THE PIGEON: CONTROL BY IMMEDIATE CONSEQUENCES
Authors: Green Leonard , Price Paul C. , Hamburger Merle E.
Published: March 2006

In three experiments pigeons played (i.e., chose between two colored keys) iterated prisoner's dilemma and other 2 × 2 games (2 participants and 2 options) against response strategies programmed on a computer. Under the prisoner's dilemma pay‐off matrix, the birds generally defected (i.e., pecked the color associated with not cooperating) against both a random response (.5 probability of either alternative) and a tit‐for‐tat strategy (on trial n the computer “chooses” the alternative that is the same as the one chosen by the subject on trial n − 1) played by the computer. They consistently defected in the tit‐for‐tat condition despite the fact that as a consequence they earned about one third of the food that they could have if they had cooperated (i.e., pecked the “cooperate” color) on all the trials. Manipulation of the values of the food pay‐offs demonstrated that the defection and consequent loss of food under the tit‐for‐tat condition were not due to a lack of sensitivity to differences in pay‐off values, nor to strict avoidance of a null pay‐off (no food on a trial), nor to insensitivity to the local (current trial) reward contingencies. Rather, the birds markedly discounted future outcomes and thus made their response choices based on immediate outcomes available on the present trial rather than on long‐term delayed outcomes over many trials. That is, the birds were impulsive, choosing smaller but more immediate rewards, and did not demonstrate self‐control. Implications for the study of cooperation and competition in both humans and nonhumans are discussed.
A QUANTITATIVE ANALYSIS OF EXTREME CHOICE
Authors: Davison Michael , Jones B. Maxwell
Published: March 2006

Six homing pigeons were trained on a variety of concurrent variable‐interval schedules in a switching‐key procedure. Unlike previous work, reinforcer ratios of up to 160 to 1 and concurrent extinction variable‐interval schedules were arranged in order to investigate choice when reinforcer‐frequency outcomes were extremely different. The data obtained over 11 conditions were initially analyzed according to the generalized matching law, which fitted the data well. The generalized matching law was then fitted only to conditions in which the reinforcer ratios were between 1 to 10 and 10 to 1. The deviations of choice measures from the other four more extreme reinforcer‐ratio conditions were significantly more towards equal choice than predicted by this second generalized matching fit. A contingency‐discriminability model, which predicts such deviations, described the data more effectively than did the generalized matching law, and also correctly predicted the maintenance of responding on both alternatives when one was associated with extinction.
A TRANSFORMATION OF SELF‐DISCRIMINATION RESPONSE FUNCTIONS IN ACCORDANCE WITH THE ARBITRARILY APPLICABLE RELATIONS OF SAMENESS, MORE THAN, AND LESS THAN
Authors: Dymond Simon , Barnes Dermot
Published: March 2006

In Experiment 1, 2 experimental subjects were given pretraining of nonarbitrary relations that brought their responses under the control of four contextual stimuli; same, opposite, more than, and less than. One control subject was not exposed to this pretraining. The 2 pretrained subjects and the 3rd nonpretrained subject then received training in six arbitrary relations, the following four relations being the most critical: same/A1‐B1, same/A1‐C1, less than/A1‐B2, more than/A1‐C2. All 3 subjects were then tested for seven derived relations, the following three relations being the most important: same/B1‐C1, more than/B1‐C2, less than/B1‐B2. The 2 pretrained subjects, but not the nonpretrained subject, showed the derived relations. One of the stimuli (B1) from the relational network and two novel stimuli (X1 and X2) were then used to train three different self‐discrimination responses on three complex schedules of reinforcement. That is, all 3 subjects were trained to pick X1 if they had not emitted a response, to pick B1 if they had emitted one response only, and to pick X2 if they had emitted two responses only. The 2 pretrained subjects, but not the nonpretrained subject, showed the predicted transformation of self‐discrimination response functions in accordance with the relations of sameness, more than, and less than (i.e., no response, pick B2; one response only, pick C1; and two responses only, pick C2). In Experiment 2, 2 new subjects were employed, and the arbitrary relational training and testing phases were modified to control for a procedural artifact that may have contributed to the results of the first experiment. Experiment 2 replicated the findings of Experiment 1. The pattern of results support the utility of a relational frames approach to understanding derived stimulus relations.
DELAYED MATCHING‐TO‐SAMPLE PERFORMANCE OF HENS: EFFECTS OF SAMPLE DURATION AND RESPONSE REQUIREMENTS DURING THE SAMPLE
Authors: Foster T. M. , Temple W. , Mackenzie C. , DeMello L. R. , Poling A.
Published: March 2006

Six domestic hens were trained under a delayed matching‐to‐sample procedure with red and green keylights as sample and comparison stimuli and a 1.5‐s delay interval. The hens were trained to stop pecking the sample stimuli when a tone sounded. Duration of the sample stimuli (2 to 10 s) and the number of pecks required on the key on which these stimuli were presented (0 to 10) were altered across conditions. Both the response requirement on the sample key and the duration of sample presentations affected accuracy. These findings are in agreement with those of earlier studies using other species and somewhat different procedures.
DISCRIMINATION TRAINING, PARTIAL REINFORCEMENT, AND INCREASES IN INTERTRIAL INTERVAL ALL REDUCE RESPONSE SPEED IN A CONTINUOUSLY REINFORCED KEY‐PECKING TASK
Authors: Reilly Steve , Macphail Euan M.
Published: March 2006

Pigeons were trained in a discrete‐trial task in which a response to the center key obtained illumination of a side key and a single response to the side key terminated a trial with either reinforcement or nonreinforcement. Center‐key speeds (i.e., reciprocals of latencies) declined with increases in intertrial interval, and it is argued that this effect is related to a decreased likelihood as intertrial interval increases that birds will be near the key at trial onset. Side‐key speeds on trials with reinforcement decreased both with increases in intertrial interval and with shifts from continuous reinforcement to either a discrimination or a partial‐reinforcement condition. The effects on side‐key speeds are compared with effects observed in alley‐running tasks using rats, and an interpretation in terms of frustration theory is offered for the results obtained in both types of task.
WITHIN‐SESSION RESPONSE RATES WHEN REINFORCEMENT RATE IS CHANGED WITHIN EACH SESSION
Authors: McSweeney Frances K. , Weatherly Jeffrey N. , Swindell Samantha
Published: March 2006

Three pigeons pecked keys and 5 rats pressed levers for food delivered on variable‐interval schedules. During baseline conditions, subjects responded on a variable‐interval 40‐s schedule throughout the session. During experimental conditions, the programmed rate of reinforcement changed every 10 min in the 50‐min sessions. When rats served as subjects, Herrnstein's (1970) hyperbolic equation provided a good description of the relation between rate of responding during a 10‐min interval and the rate of reinforcement obtained during that interval. Responding, measured over 10‐min blocks, was also approximately equally sensitive to changes in the programmed rate of reinforcement at all times in the session. Herrnstein's equation provided a poorer description of the changes in responding when pigeons served as subjects. Differences in experimental experience or differences in the absolute rates at which subjects responded may have contributed to the differences in results for these different species.
ASSESSING PREFERENCE FOR REINFORCERS USING DEMAND CURVES, WORK‐RATE FUNCTIONS, AND EXPANSION PATHS
Authors: Tustin R. Don
Published: March 2006

A behavioral economic model that explains the choice and allocation of work rate is used to predict performance patterns in three contexts: with single schedules, with concurrent schedules when total reinforcement is low, and with concurrent schedules when reinforcement increases. Performance in the three contexts is predicted to change in orderly ways depending on how the subject evaluates the reinforcers earned. Quadrant diagrams are used to generate reinforcer demand functions, work‐rate supply functions, and reinforcement‐rate expansion paths. Preference between reinforcers is viewed as being a variable, with preference reversing in some situations.
BEHAVIORAL ECONOMICS OF CONCURRENT ETHANOL‐SUCROSE AND SUCROSE REINFORCEMENT IN THE RAT: EFFECTS OF ALTERING VARIABLE‐RATIO REQUIREMENTS
Authors: Petry Nancy M. , Heyman Gene M.
Published: March 2006

These experiments examined the own‐price and cross‐price elasticities of a drug (ethanol mixed with 10% sucrose) and a nondrug (10% sucrose) reinforcer. Rats were presented with ethanol‐sucrose and sucrose, both available on concurrent independent variable‐ratio (VR) 8 schedules of reinforcement. In Experiment 1, the variable ratio for the ethanol mix was systematically raised to 10, 12, 14, 16, 20, and 30, while the variable ratio for sucrose remained at 8. Five of the 6 rats increased ethanol‐reinforced responding at some of the increments and defended baseline levels of ethanol intake. However, the rats eventually ceased ethanol‐reinforced responding at the highest variable ratios. Sucrose‐reinforced responding was not systematically affected by the changes in variable ratio for ethanol mix. In Experiment 2, the variable ratio for sucrose was systematically increased while the ethanol‐sucrose response requirement remained constant. The rats decreased sucrose‐reinforced responding and increased ethanol‐sucrose‐reinforced responding, resulting in a two‐ to 10‐fold increase in ethanol intake. Experiment 3 examined the substitutability of qualitatively identical reinforcers: 10% sucrose versus 10% sucrose. Increases in variable‐ratio requirements at the preferred lever resulted in a switch in lever preference. Experiment 4 examined whether 10% ethanol mix substituted for 5% ethanol mix, with increasing variable‐ratio requirements of the 5% ethanol. All rats eventually responded predominantly for the 10% ethanol mix, but total amount of ethanol consumed per session did not systematically change. In Experiment 5, the variable‐ratio requirements for both ethanol and sucrose were simultaneously raised to VR 120; 7 of 8 rats increased ethanol‐reinforced responding while decreasing sucrose‐reinforced responding. These data suggest that, within this ethanol‐induction procedure and within certain parameters, demand for ethanol‐sucrose was relatively inelastic, and sucrose consumption was independent of ethanol‐sucrose consumption. Demand for sucrose, on the other hand, was relatively elastic, and ethanol‐sucrose readily substituted for it. The results are discussed in terms of applying a behavioral economic approach to relationships between drug and nondrug reinforcers.
UNIT‐PRICE ANALYSIS OF OPIOID CONSUMPTION BY MONKEYS RESPONDING UNDER A PROGRESSIVE‐RATIO SCHEDULE OF DRUG INJECTION
Authors: English Justin A. , Rowlett James K. , Woolverton William L.
Published: March 2006

Several reports have indicated that drug consumption in self‐administration procedures is a function of the ratio of the instrumental requirement to the dose of drug, a quantity termed unit price. We evaluated three predictions from this unit‐price model in a reanalysis of data on opioid self‐administration in rhesus monkeys responding under a progressive‐ratio schedule (Hoffmeister, 1979). We evaluated whether consumption was inversely related to unit price, and compared the goodness of fit of an equation devised by Hursh, Raslear, Shurtleff, Bauman, and Simmons (1988) to that of a linear model predicting consumption as a function of dose. We also tested whether consumption was constant when the same unit price was comprised of different combinations of dose and instrumental requirement Consumption declined overall as unit price increased. The equation devised by Hursh et al. and the linear model based on dose fit the data equally well. Drug consumption was not uniform at a given unit price. The analyses suggest limits on the unit‐price model as a characterization of drug consumption.