bluuebunny/crossref_metadata_2025 huggingface dataset:
SIGNAL PROBABILITY, REINFORCEMENT AND SIGNAL DETECTION
Authors: McCarthy Dianne , Davison Michael
Published: March 2006

Five pigeons were trained to detect differences in light intensity. Two stimuli, S1 and S2, differing in intensity, were arranged on the center key of a three‐key chamber according to set probabilities. A peck on the center key turned on the two side keys. When S1 was presented on the center key, a peck on the left key was “correct” and when S2 was presented, a peck on the right key was “correct.” Correct responses produced reinforcement and incorrect responses produced 3‐second blackout. Detection performance was measured under three procedures. The first was a standard signal‐detection design in which the probability of S1 was varied and the number of reinforcements obtained for correct responses to S1 was allowed to covary. In the second procedure, the probability of S1 was again varied but the distribution of reinforcements between the two choices was kept equal. In the third procedure, probability of S1 was held constant while the distribution of reinforcements was varied between the two choices. Changes in response bias were a function of variations in the relative reinforcement ratio for the choice responses and not a function of variations in the probability of stimulus presentation. Discriminability remained constant across the three procedures.
CHAINED SCHEDULES OF AVOIDANCE: REINFORCEMENT WITHIN AND BY AVOIDANCE SITUATIONS
Authors: Dewaard Richard J. , Galizio Mark , Baron Alan
Published: March 2006

Four rats were exposed to chained schedules with variable‐cycle avoidance in both links. Responding in the initial link cancelled shocks scheduled once per minute and, according to a conjoint fixed‐ratio schedule, produced a terminal link where scheduled shock rates varied from 0 to 8 shocks per minute in different conditions of the experiment. Response rates in the terminal link increased as a function of the scheduled shock rate. Response rates in the initial link, on the other hand, decreased as a function of the shock rate actually received (rather than scheduled) in the terminal link. While consistent with other studies of aversive control, these results differ from those obtained in chained schedules of positive reinforcement in that increases in reinforcement within the terminal link of the chain did not systematically increase the reinforcing value of that link.
CHOICE FOR SIGNALED OVER UNSIGNALED SHOCK AS A FUNCTION OF SIGNAL LENGTH
Authors: Abbott Bruce , Badia Pietro
Published: March 2006

Subjects chose between signaled and unsignaled shock conditions while signal length was varied between .5 and 2.0 seconds in steps of .5 seconds in both ascending and descending series. Preference for the signaled condition failed to develop initially for five of six subjects when signals were .5 or 1.0 seconds but became strong for all subjects when signals were 2.0 seconds (ascending series). Preference declined when signals were shortened, but for most subjects this decline was small (descending series). Since discriminable shock‐free periods were present in the signaled condition at all signal lengths, these results suggest that safety may not be a sufficient condition for preference to develop for signaled shock.
AN EXPERIMENTAL ANALYSIS OF THE EFFECTS OF d‐AMPHETAMINE AND COCAINE ON THE ACQUISITION AND PERFORMANCE OF RESPONSE CHAINS IN MONKEYS
Authors: Thompson Donald M. , Moerschbaecher Joseph M.
Published: March 2006

In one component of a multiple schedule of food presentation, monkeys acquired a different four‐response chain each session by responding sequentially on three keys in the presence of four geometric forms (learning). In the other component, the four‐response chain was the same each session (performance). Both d‐amphetamine and cocaine, at the higher doses, disrupted the behavior in the learning component; the overall response rate decreased, the overall accuracy was impaired (i.e., percent errors increased), and there was less within‐session error reduction. The performance component was generally less sensitive than the learning component to the disruptive effects of both drugs on rate and accuracy. After prefeeding or during an extended session, the response rate decreased in both components, but accuracy was generally unaffected. When the four discriminative stimuli in both components were removed, the behavior was disrupted to a greater extent in the performance component. The disruptive effects of both drugs on behavior in the learning component were attenuated when the drugs were administered during the session after the response chain had been acquired. It was concluded that the greater sensitivity of the learning component to disruptive drug effects is related to the relatively weak stimulus control and/or the lower rate of reinforcement associated with that component.
DEFINING BEHAVIORAL CONTRAST FOR MULTIPLE SCHEDULES
Authors: McSweeney Frances K. , Norman Wayne D.
Published: March 2006

Two different definitions of behavioral contrast have been used for multiple schedules. One, interschedule, definition identifies contrast as changes in the rates of responding which occur when subjects move from one multiple schedule to another. The other, intraschedule, definition emphasizes changes in the rates of responding which occur relative to a baseline rate of responding. The baseline is the rate of responding emitted during a multiple schedule that supplies equal rates of reinforcement in the two components. The distinction between these two definitions is important for empirical and theoretical reasons. For example, theoretical confusion has arisen when the interschedule definition has been used to test and reject theories which implicitly define contrast by the intraschedule definition.
CHOICE AND NUMBER OF REINFORCERS
Authors: Moore Jay
Published: March 2006

Pigeons were exposed to the concurrent‐chains procedure in two experiments designed to investigate the effects of unequal numbers of reinforcers on choice. In Experiment 1, the pigeons were indifferent between long and short durations of access to variable‐interval schedules of equal reinforcement density, but preferred a short high‐density terminal link over a longer, lower density terminal link, even though in both sets of comparisons there were many more reinforcers per cycle in the longer terminal link. In Experiment 2, the pigeons preferred five reinforcers, the first of which was available after 30 sec, over a single reinforcer available at 30 sec, but only when the local interval between successive reinforcers was short. The pigeons were indifferent when this local interval was sufficiently long. The pigeons' behavior appeared to be under the control of local terminal‐link variables, such as the intervals to the first reinforcer and between successive reinforcers, and was not well described in terms of transformed delays of reinforcement or reductions in average delay to reinforcement.
CHOICE: EFFECTS OF CHANGEOVER SCHEDULES ON CONCURRENT PERFORMANCE
Authors: Tustin R. D. , Davison Mike
Published: March 2006

The components of concurrent schedules were separated temporally by placing interval schedules on the changeover key. The rates of responding on both the main and changeover keys were examined as a function of the reinforcement rates. In the first experiment, the sensitivity of main‐key performance to changing reinforcement rates was inversely related to the temporal separation of components, and changeover performance was monotonically related to the ratio of the reinforcement rates. In the second experiment, when the ratio of the reinforcement rates was scheduled to remain constant while the frequency of reinforcement was varied, changeover performance did not remain constant. A “sampling” interpretation of changeover responding was proposed and subsequently tested in a third experiment where extinction was always scheduled in one component and the frequency of reinforcement was varied in the second component. It was concluded that changeover performance can be interpreted using molar measures of reinforcement and that animals sample activities available to them at rates which are controlled by relative reinforcement rates.
EFFECTS OF RESPONSE‐INDEPENDENT NEGATIVE REINFORCERS ON NEGATIVELY REINFORCED KEY PECKING
Authors: Hutton Larrie , Lewis Paul
Published: March 2006

Previous research has shown that presenting response‐independent positive reinforcers reduces the response rate of an operant maintained by positive reinforcement. The present experiment investigated a similar effect using shock‐free time as a negative reinforcer. Brief shocks were delivered in the presence of a distinctive stimulus, and pigeon's key pecks were reinforced by the occasional presentation of a 2‐minute shock‐free period. Extra 2‐minute shock‐free periods were added independently of behavior. For each of three pigeons, response rate during shock‐on periods declined with added shock‐free periods; the more frequently the extra shock‐free periods occurred the greater the decline in response rate. This outcome is predicted by extending the Law of Effect to include negative reinforcement.
CONTROL OF THE TEMPORAL LOCATION OF POLYDIPSIC LICKING IN THE RAT
Authors: Alferink Larry A. , Bartness Tim J. , Harder Stuart R.
Published: March 2006

We studied the variables controlling the temporal location of polydipsic licking. Four rats were trained on a mixed fixed‐ratio 10 (no tone) chained fixed‐ratio 10 (no tone) fixed‐ratio 90 (tone) schedule and on a multiple fixed‐ratio 10 (tone) fixed ratio 100 (no tone) schedule. On the multiple schedule, drinking followed pellets if a fixed ratio 100 was upcoming for all four subjects and for two of the subjects if a fixed ratio 10 was upcoming. On the mixed schedule, drinking preceded the fixed‐ratio 90 component of the chain. Two subjects also drank after pellet delivery on the mixed schedule before both the fixed ratio 10 and the chain components. The number of licks was greater following a pellet than following a response. In a second phase with two of these subjects, the total response requirement of the chain was held constant at 100, while the size of the two ratios that constituted the chain was varied inversely. The tone signaled onset of the second link. Drinking followed the tone when it signaled fixed‐ratio 90, 95, or 100 but not when it signaled fixed ratio 75, 80, or 85. These results show, on the one hand, that polydipsic licking is controlled by discriminative properties of the pellet rather than by its eliciting or “thirst‐producing” characteristics. On the other hand, the fact that drinks were longer following a pellet than following a response suggests a contribution of thirst to polydipsia.
UNDERMATCHING ON CONCURRENT VARIABLE‐INTERVAL SCHEDULES AND THE POWER LAW
Authors: Wearden J. H.
Published: March 2006

The phenomenon of undermatching on concurrent variable‐interval schedules is shown to be derivable by transforming the individual interreinforcement intervals of each variable‐interval schedule and averaging the transformed values to produce an “estimate” of the rate of reinforcement the schedules deliver. If the transformation is based on a power function with a fractional exponent, such as is found in many studies of temporal control in animals, matching response ratios to the ratios of these estimated rates of reinforcement yields undermatching. If the concurrent variable‐interval schedules are arranged such that the individual intervals in each schedule have a constant proportionality (a procedure found in many commonly used variable‐interval schedules) the slope of the line relating logarithms of response ratios and of programmed reinforcement ratios is identical to the exponent of the power transformation applied to the individual time intervals in the variable‐interval schedules. In other cases this simple relation does not hold but the degree of undermatching is greater the lower the value of the exponent of the power function. This account of undermatching predicts values similar to those typically observed.
TOWARD A QUANTITATIVE THEORY OF PUNISHMENT
Authors: de Villiers Peter A.
Published: March 2006

In two experiments, pigeons' key pecking for food on concurrent variable‐interval schedules was punished with electric shock according to concurrent variable‐interval punishment schedules. With unequal frequencies of food but equal rates of punishment associated with the two keys and at several intensities of shock, the response and time allocation of all six pigeons overmatched the obtained relative frequency of food. The overmatching was predicted by a subtractive model of the interaction between punishment and positive reinforcement but not by two alternative models. Increases in the k and re parameters of the generalized matching law could not account for the observed shifts in preference.
DEVELOPMENT OF COMPLEX, STEREOTYPED BEHAVIOR IN PIGEONS
Authors: Schwartz Barry
Published: March 2006

A pigeon's peck on one key moved a light down one position in a 5 × 5 matrix of lights, while a peck on another key moved the light across one position. Reinforcement depended upon the occurrence of four pecks on each key (moving the matrix light from the top left to the bottom right), and a fifth peck on either key ended a trial without food. Though there were 70 different sequences that led to reinforcement, each of 12 pigeons developed a particular, stereotyped sequence which dominated its behavior (Experiment 1). Extinction produced substantial increases in sequence variability (Experiment 2). Removal of the matrix cues disrupted performance, though it partially recovered with extended training (Experiment 3). The pigeons did not master a contingency which required a different sequence on the current trial than on the previous one (Experiment 4), though they were able to learn to emit sequences which began with either left‐left or left‐right response patterns (Experiment 5). The experiments suggest that contingencies of reinforcement may contribute to the creation of complex units of behavior, and that stereotypy may be a likely consequence of contingent reinforcement.
TEMPORAL DISCRIMINATION AND A FREE‐OPERANT PSYCHOPHYSICAL PROCEDURE
Authors: Stubbs D. Alan
Published: March 2006

Pigeons were presented a series of keylight time periods (separated by blackouts) during which two response keys were lit, one by blue light and the other either by orange or green. Blue‐key responses changed the color on the other key. Orange‐key responses sometimes produced food during the first half of a time period; green‐key responses sometimes produced food during the second half. In three experiments, the probability of a green‐key response increased as a function of elapsed time. Experiment 1 compared performance when the duration of the keylight periods was varied across a wide range. Discrimination performance was similar across the range of durations. Experiment 2 varied both relative reinforcement rate and the local reinforcement rate for orange‐key and green‐key responses. These manipulations produced changes in response bias but not discrimination sensitivity. Experiment 3 varied the local temporal placement of reinforcers within time periods and demonstrated that choice behavior was affected by differential reinforcement at different points during the time periods. The results were consistent with previous research on duration discrimination that used psychophysical trials procedures.
RESPONSE STRENGTH IN MULTIPLE PERIODIC AND APERIODIC SCHEDULES
Authors: Mandell Charlotte
Published: March 2006

Responding in multiple periodic and aperiodic schedules of equal mean reinforcement rate was examined during extinction, satiation, and in the presence of various free‐food schedules. In Experiments I and II, pigeons were trained on multiple variable‐interval‐fixed‐interval schedules. Decreases in the rate of responding due to extinction, satiation, or food schedules were approximately equal regardless of the temporal pattern of reinforcer presentation. In Experiment III, pigeons responded on a two‐component multiple schedule in which each component was a two‐member homogeneous response chain terminating in a fixed‐interval schedule during one component and in a variable‐interval schedule during the other. The length of both terminal links was varied over a series of conditions. Initial‐link responding in the fixed‐interval component was reduced more by increasing terminal‐link length than was initial‐link responding in the variable‐interval component. However, no differences in resistance to satiation and extinction were obtained across the fixed and variable components. If the relative decrease in responding produced by satiation and extinction is used as an index of the “value” of the conditions maintaining responding, then these data suggest that fixed and variable schedules of equal mean length are equally valued. This conclusion, however, is not consistent with findings of preference for variable over fixed schedules obtained in studies using concurrent‐chain procedures.
ALTERNATIVE FIXED‐RATIO FIXED‐INTERVAL SCHEDULES OF REINFORCEMENT
Authors: Rider David P.
Published: March 2006

Five rats were trained under alternative fixed‐ratio fixed‐interval schedules, in which food reinforcement was provided for the completion of either a fixed‐ratio or a fixed‐interval requirement, whichever was met first. Overall response rate and running rate (the rate of responding after the postreinforcement pause) decreased for all subjects as the fixed‐ratio value increased. As the proportion of reinforcements obtained from the fixed‐ratio component increased and the alternative schedule approached a simple fixed ratio, overall response rate and running rate both increased; conversely, as the proportion of reinforcements obtained from the fixed‐interval component increased and the alternative schedule approached a simple fixed interval, response rates decreased. Postreinforcement pause length increased linearly as the average time between reinforcements increased, regardless of the schedule parameters. A break‐run pattern of responding was predominant at low‐and medium‐valued fixed ratios. All subjects displayed at least occasional positively accelerated responding within interreinforcement intervals at higher fixed‐ratio values.
DISCRIMINATION AND DIFFERENTIATION OF RESPONSE NUMBER IN STIMULUS DIRECTED PECKING OF PIGEONS
Authors: Dodd Peter W. D.
Published: March 2006

In Experiment 1, autoshaping trials terminated with food only if pigeons emitted more than a target number of responses during a trial in one condition and fewer than a target number in another. The median number of responses per trial shifted in accordance with the requirements. The responding of yoked‐control birds that received response‐independent reinforcers did not vary with the response requirements. In Experiment 2, the number of responses in an autoshaping trial became the discriminative stimulus for reinforcement in the second component of a chained schedule. In one condition, responding was reinforced only if the number of responses in the first component was above a target value; in the other condition, responding was reinforced only if the number was below the target value. The distribution of the first‐component response numbers did not shift systematically between discrimination conditions, but response rates in the second component indicated that the number of responses in the autoshaping trial was a discriminable property of behavior.
REDUCTION OF SHOCK DURATION AS NEGATIVE REINFORCEMENT IN FREE‐OPERANT AVOIDANCE
Authors: Bersh Philip J. , Alloy Lauren B.
Published: March 2006

Rats were trained on a free‐operant procedure in which shock duration was controlled by responses within a limited range of interresponse times. Shocks of 1.6‐mA intensity occurred randomly with average density of 10 shocks per minute. As long as interresponse times were 15 seconds or less, any shocks received were at the briefer of two durations (.3 second). Whenever interresponse times exceeded 15 seconds, any shocks received were at the longer duration (1.0 second). For six of eight animals, avoidance responding developed quickly and reached levels of better than 90%. Four yoked animals stopped responding within the first few sessions. Shock duration reduction without change in shock probability or intensity was sufficient for the acquisition and maintenance of avoidance responding.
CHOICE AND REINFORCEMENT DELAY
Authors: Gentry G. David , Marr M. Jackson
Published: March 2006

Previous studies of choice between two delayed reinforcers have indicated that the relative immediacy of the reinforcer is a major determinant of the relative frequency of responding. Parallel studies of choice between two interresponse times have found exceptions to this generality. The present study looked at the choice by pigeons between two delays, one of which was always four times longer than the other, but whose absolute durations were varied across conditions. The results indicated that choice is not uniquely determined by the relative immediacy of reinforcement, but that absolute delays are also involved. Models for concurrent chained schedules appear to be more applicable to the present data than the matching relation; however, these too failed to predict choice for long delays.
CONDITIONAL DISCRIMINATION LEARNING: A CRITIQUE AND AMPLIFICATION
Authors: Schrier Allan M. , Thompson Claudia R.
Published: March 2006

Carter and Werner recently reviewed the literature on conditional discrimination learning by pigeons, which consists of studies of matching‐to‐sample and oddity‐from‐sample. They also discussed three models of such learning: the “multiple‐rule” model (learning of stimulus‐specific relations), the “configuration” model, and the “single‐rule” model (concept learning). Although their treatment of the multiple‐rule model, which seems most applicable to the pigeon data, is generally excellent, their discussion of the other two models is incomplete and sometimes inaccurate. Potential problems of terminology are discussed in the present paper, as are additional lines of research that deserve consideration by those interested in further work in this area. The issue of response versus stimulus selection (configuration versus compound‐cue learning) is discussed in connection with the configuration model. Particular attention is given to Carter and Werner's criticism of the application, in studies with other species, of the learning set procedure in testing for single‐rule learning. Some of the important related issues are: the bias for improvement on new problems in a series, the adequacy of a multiple‐rule model to explain learning set formation, and evidence in favor of the single‐rule model, at least in primates. Consideration of these additional contributions to the study of conditional discrimination learning emphasizes the usefulness of this task in the comparative study of cognitive processes.
SHAPING THE LOCATION OF A PIGEON'S PECK: EFFECT OF RATE AND SIZE OF SHAPING STEPS
Authors: Eckerman David A. , Hienz Robert D. , Stern Sander , Kowlowitz Vicki
Published: March 2006

For several pigeons, pecking at particular locations within a ten‐inch‐wide response area was reinforced by grain presentations. The reinforced locations changed systematically to “shape” response location back and forth across the area. The rate and size of these shifts in reinforced locations were varied in both between‐subject and within‐subject comparisons to evaluate the influence of these variables on the shaping process. Larger step sizes produced larger shifts in location for all sizes inspected, with all sizes from .5 to 3.0 inches effective in shaping behavior. More rapid steps were approximately as effective as slower steps for all rates of shift inspected from 25 reinforcers to 400 reinforcers per step. These data suggest that shaping peck location proceeds most efficiently with rapid, relatively large shifts in criterion performance.
REINFORCEMENT AND PUNISHMENT EFFECTS IN CONCURRENT SCHEDULES: A TEST OF TWO MODELS
Authors: Farley Joseph
Published: March 2006

The joint effects of punishment and reinforcement on the pigeon's key‐peck response were examined in three choice experiments conducted to compare predictions of Farley and Fantino's (1978) subtractive model with those made by Deluty's (1976) and Deluty and Church's (1978) model of punishment. In Experiment 1, the addition of equal punishment schedules to both alternatives of a concurrent reinforcement schedule enhanced the preference exhibited for the more frequent reinforcement alternative. Experiment 2 demonstrated decreases in the absolute response rate for each member of a concurrent reinforcement schedule when increasing frequencies of punishment were added to each alternative. Experiment 3 found that preference for the denser of two reinforcement schedules diminished when the absolute frequencies of reinforcement were increased by a constant factor and conditions of punishment for both alternatives were held constant. Diminished preferences were obtained regardless of whether the frequency of punishment associated with the denser reinforcement schedule was greater or less than that associated with the lean reinforcement alternative. The results from all three experiments uniquely supported Farley and Fantino's (1978) subtractive model of punishment and reinforcement.
CONTEXT DEPENDENT CHANGES IN THE REINFORCING STRENGTH OF SCHEDULE‐INDUCED DRINKING
Authors: Heyman Gene M. , Bouzas Arturo
Published: March 2006

Previous experiments show that the opportunity to engage in schedule‐induced responding is reinforcing. In this experiment, the reinforcing strength of schedule‐induced drinking was measured. Four rats were trained on a concurrent‐chain schedule. The two terminal links provided food pellets on identical fixed‐time schedules. In addition, one terminal link also provided the opportunity to press a button that operated a water dipper. In this link, the rats showed polydipsic drinking. Button‐pressing rate for polydipsic drinking was a bitonic function of pellet rate, and it was possible to describe the relationship with a slightly modified version of the matching equation for primary reinforcement. This equation also closely fit the data from other studies. Initial‐link response rates, however, did not appear to be influenced by the availability of water in the terminal links. Control conditions suggested that the reinforcing strength of polydipsia was strongly bound to the context provided by periodic food reinforcement.
SHORT‐TERM MEMORY IN THE RHESUS MONKEY: A BEHAVIORAL ANALYSIS OF DELAYED‐RESPONSE PERFORMANCE
Authors: Kojima Shozo
Published: March 2006

This study obtained quantitative data on the bodily orientations of rhesus monkeys in a delayed‐response task and determined whether such orientations mediate the correct response in a choice trial. The basic task was a two‐key chain schedule with the key leading to food signaled in the initial component. During the subsequent delay interval, the signal was removed, but it was necessary that one of the keys be pressed to advance the schedule to the terminal choice component. The position of the key pressed thus indicated orientation during the delay interval. When the monkeys had free access to the left and right keys, they tended to press the key leading to food throughout the chain schedule components and received food on more than 85% of the trials, even when the delay was extended to 20 seconds. However, when orientation toward the food key was disrupted by forcing the monkeys to press an extraneous center key during the delay, choice performance deteriorated. Requiring the center key presses early, rather than late, in the delay component had a strong disruptive effect. The relation of the results to the mediating coding‐response hypothesis is discussed.
DELAY‐INTERVAL ILLUMINATION CHANGES INTERFERE WITH PIGEON SHORT‐TERM MEMORY
Authors: Tranberg Daniel K. , Rilling Mark
Published: March 2006

Pigeons acquired a successive delayed matching‐to‐sample task at delay intervals ranging from 2.5 to 7 seconds. Test sessions were conducted during which delay‐interval illumination conditions were changed from those illumination conditions that prevailed during the baselines. Compared to baseline delayed matching performance, changing delay‐interval illumination disrupted matching. This disruption occurred whether the change in delay‐interval illumination represented an increase or a decrease, relative to the baseline, and whether there was or was not a change in illumination during the test session. It was concluded that illumination per se introduced during delay intervals of delayed matching tasks does not interfere with pigeon short‐term memory. Rather, a change in delay‐interval illumination, relative to the baseline, appears to retroactively interfere in pigeon short‐term memory.
AN ANALYTIC COMPARISON OF HERRNSTEIN'S EQUATIONS AND A MULTIVARIATE RATE EQUATION
Authors: McDOWELL J. J.
Published: March 2006

Herrnstein's equations are approximations of the multivariate rate equation at ordinary rates of reinforcement and responding. The rate equation is the result of a linear system analysis of variable‐interval performance. Rate equation matching is more comprehensive than ordinary matching because it predicts and specifies the nature of concurrent bias, and predicts a tendency toward undermatching, which is sometimes observed in concurrent situations. The rate equation contradicts one feature of Herrnstein's hyperbola, viz., the theoretically required constancy of k. According to the rate equation, Herrnstein's k should vary directly with parameters of reinforcement such as amount or immediacy. Because of this prediction, the rate equation asserts that the conceptual framework of matching does not apply to single alternative responding. The issue of the constancy of k provides empirical grounds for distinguishing between Herrnstein's account and a linear system analysis of single alternative variable‐interval responding.
A REVISED LIST OF SPANISH TRANSLATIONS OF OPERANT TERMINOLOGY
Authors: Gallegos Xochitl , Colotla Victor A.
Published: March 2006

The experimental analysis of behavior has grown enormously in Latin America within the last decade. This paper offers an updating revision of suggested Spanish translations of operant expressions.
VISUAL ATTENTION IN RETARDED ADULTS: COMBINING STIMULI WHICH CONTROL INCOMPATIBLE BEHAVIOR
Authors: Huguenin Nancy H. , Touchette Paul E.
Published: March 2006

Eight severely retarded young men learned color and line‐tilt discriminations. After 95% accuracy was achieved for both dimensions, they were combined to form “conflict‐compound” stimuli in which prior reinforcement history was reversed for one element of the compound and unchanged for the other. When responding to the compound was 95% accurate, control exerted by each element was measured. The unchanged element consistently exercised control in agreement with the reinforcement contingencies associated with the compound, regardless of whether it was color or line orientation. The reversed element, which had a conflicting prior history or reinforcement, most often exerted control associated with original training, or no control, suggesting that it had been “ignored” during the compound. Conflict compounds produced selective attention. When elements were combined to form “compatible‐compound” stimuli, both exercised control in agreement with the compound in post‐tests. Selective attention was not produced by compatible compounds.
MAINTENANCE OF RESPONDING BY SQUIRREL MONKEYS UNDER A CONCURRENT SHOCK‐POSTPONEMENT, FIXED‐INTERVAL SHOCK‐PRESENTATION SCHEDULE
Authors: Barrett James E. , Stanley Jennifer A.
Published: March 2006

A chain‐pulling response was initially developed under a shock‐postponement (avoidance) schedule with two squirrel monkeys. Few responses occurred on a lever where responding initially had no scheduled consequence or, subsequently, when a 3‐minute fixed‐interval shock‐presentation schedule was concurrently arranged for lever responses. Appropriate rates and patterns of lever responding developed and were later maintained under the fixed‐interval 3‐minute shock‐presentation schedule alone when the chain and shock‐postponement schedule were removed. When both the shock‐postponement and shock‐presentation schedules were again simultaneously in effect, steady rates of chain pulling were maintained by the shock‐postponement schedule and positively accelerated rates and patterns were maintained on the lever by the shock‐presentation schedule. Response rates under both schedules were directly related to shock intensity. A history of exposure to a shock‐postponement schedule, even though with a topographically different response and manipulandum, was sufficient for the development and eventual maintenance of responding by the presentation of shock. Further, differential performances can be maintained simultaneously by the presentation and postponement of electric shock.
PHYSICAL RESTRAINT PRODUCES RAPID ACQUISITION OF THE PIGEON'S KEY PECK
Authors: Locurto C. M. , Travers Tania , Terrace H. S. , Gibbon John
Published: March 2006

The acquisition and maintenance of autoshaped key pecking in pigeons was studied as a function of intertrial interval. At each of six intervals, which ranged from 12 seconds to 384 seconds, four pigeons were physically restrained during training while four other pigeons were not restrained. Restrained subjects acquired key pecking faster and with less intragroup variability at each interval. The effects of restraint were specific to acquisition and were not evident in maintained responding after five postacquisition sessions.
CHOICE BETWEEN REWARDS DIFFERING IN AMOUNT AND DELAY: TOWARD A CHOICE MODEL OF SELF CONTROL
Authors: Green Leonard , Snyderman Mark
Published: March 2006

A concurrent‐chain procedure was used to study pigeons' choices between rewards differing in both amount and delay. The shorter delay terminated with a 2‐second access to grain whereas the longer delay terminated with a 6‐second access to grain. The ratio of the delays was constant within a given condition while their absolute values were varied. Over conditions, ratios of 6:1, 3:1, and 3:2 were studied. As the absolute values of the delays to reinforcement increased, preference for the longer‐delayed but larger reward decreased under both the 6:1 and 3:1 ratios, but increased under the 3:2 ratio. These results are inconsistent with choice models predicting no change in preference when the ratios of delays and amounts are held constant. In addition, the change in preference under the 3:1 ratio is inconsistent with a simple multiplicative interaction of the trade off between reinforcer amount and delay, and suggests that delay is a more potent determinant of choice than is amount. These results have implications for models that view choice between small immediate rewards and large but delayed rewards as underlying the behavior commonly called self control.
KEY‐PECK DURATIONS UNDER BEHAVIORAL CONTRAST AND DIFFERENTIAL REINFORCEMENT
Authors: Whipple William R. , Fantino Edmund
Published: March 2006

Pigeons were maintained on a multiple schedule in which both components were variable‐interval one‐minute schedules. When they were switched to a condition in which one component was extinction, behavioral contrast was observed. The median durations of the key pecks in the unchanged component did not decrease in size. The results are incompatible with a theory of behavioral contrast which considers the added pecks to be short‐duration responses. In a second experiment, pigeons were required to emit short‐duration key pecks in one component of a multiple schedule, and long‐duration pecks in the other. Two of three pigeons learned to emit responses appropriate to the requirements of the component in effect, suggesting that the duration of the key‐peck response is sensitive to differential reinforcement.
REINFORCEMENT OF HUMAN OBSERVING BEHAVIOR BY A STIMULUS CORRELATED WITH EXTINCTION OR INCREASED EFFORT
Authors: Perone Michael , Baron Alan
Published: March 2006

Young men pulled a plunger on mixed and multiple schedules in which periods of variable‐interval monetary reinforcement alternated irregularly with periods of extinction (Experiment 1), or in which reinforcement was contingent on different degrees of effort in the two alternating components (Experiment 2). In the baseline conditions, the pair of stimuli correlated with the schedule components could be obtained intermittently by pressing either of two observing keys. In the main conditions, pressing one of the keys continued to produce both discriminative stimuli as appropriate. Pressing the other key produced only the stimulus correlated with variable‐interval reinforcement or reduced effort; presses on this key were ineffective during periods of extinction or increased effort. In both experiments, key presses producing both stimuli occurred at higher rates than key presses producing only one, demonstrating enhancement of observing behavior by a stimulus correlated with the less favorable of two contingencies. A control experiment showed that stimulus change alone was not an important factor in the maintenance of the behavior. These findings suggest that negative as well as positive stimuli may play a role in the conditioned reinforcement of human behavior.
ALTERNATIVE REINFORCEMENT EFFECTS ON FIXED‐INTERVAL PERFORMANCE
Authors: Lattal Kennon A. , Boyer Susan S.
Published: March 2006

Pigeons' key pecks were reinforced with food on a fixed‐interval schedule. Food also was available at variable time periods either independently of responding or for not key pecking (a differential‐reinforcement‐of‐other‐behavior schedule). The latter condition arranged reinforcement following the first pause of t seconds after it became available according to a variable‐time schedule. This schedule allowed separation of the effects of pause requirements ≤ five‐seconds and reinforcement frequency. The time spent pausing increased as the duration of the pause required for reinforcement increased from 0 to 30 seconds and as the frequency of reinforcement for pausing increased from 0 to 2 reinforcers per minute. Key pecking was more evenly distributed within each fixed interval with shorter required pauses and with more frequent reinforcement for pausing. The results complement those obtained with other concurrent schedules in which the same operant response was reinforced in both components.
SECOND‐ORDER AUTOSHAPED KEY PECKING BASED ON AN AUDITORY STIMULUS
Authors: Burt J. S. , Westbrook R. F.
Published: March 2006

In Experiment 1, pigeons were exposed either to paired or to unpaired presentations of a tone and grain, and then to paired presentations of a keylight with the tone. Substantial second‐order conditioned pecking to the keylight was produced in the birds that had received paired presentations of tone and grain. In Experiment 2, second‐order pecking to the keylight increased in probability across four groups that had received, respectively, 20, 80, 140, or 200 paired presentations of tone and grain. In Experiment 3, the amount of pecking directed towards a keylight which predicted the first‐order, tone CS was as substantial in birds without a prior history of key pecking as in birds with such a history. A further experiment failed to discover any significant differences in the levels of second‐order pecking to a keylight paired with a first‐order tone CS or with a first‐order keylight CS. Thus, an auditory signal that does not itself support pecking may enable a localized visual stimulus to evoke key pecking.
MIRROR PECKING AND TIMEOUT UNDER A MULTIPLE FIXED‐RATIO SCHEDULE OF FOOD DELIVERY
Authors: Ator Nancy A.
Published: March 2006

Pigeons were trained to peck a key under a multiple fixed‐ratio 25 fixed‐ratio 175 schedule of food presentation. In the first condition, either a mirror or the opportunity to produce a 30‐second timeout were available. In a second condition, mirror and timeout availability were reversed for the two groups. Following a return to the initial condition, mirror and timeout keys were presented together for all birds. Mirror and timeout responses occurred predominantly in the pause in the larger fixed‐ratio component, regardless of whether the opportunities for the two responses were available singly or together. Mirror responding occurred in a greater proportion of the pauses than did timeouts. When the opportunities for both mirror pecking and timeout were available concurrently, they occurred with probabilities similar to those under the single conditions. Within the pause itself, mirror responses most frequently occurred immediately after reinforcement. Timeouts occurred most frequently toward the end of the pause, and some timeouts occurred in the early part of the run. Longer preratio pausing occurred in the larger fixed‐ratio component in the conditions in which the mirror was present, whether or not any mirror pecks were recorded.
MEMORY FOR SEQUENCES OF STIMULI AND RESPONSES
Authors: Wasserman Edward A. , Nelson Keith R. , Larew Mark B.
Published: March 2006

Two experiments sought to determine if pigeons could discriminate and remember recent sequences of stimuli and responses. A variant of Konorski's short‐term memory procedure involving successive presentation of sample and test stimuli was used. The samples were stimulus‐response pairs of the form, (S‐R)1‐(S‐R)2. Differential test responding disclosed memory of the two‐item samples, with birds showing earlier and greater control by the second item than the first (Experiment 1). When the retention interval separating the second item of the sample sequence from the test stimulus was lengthened from .5 to 2.0 or 4.0 sec, a systematic loss of stimulus control resulted; however, when varied over the same temporal range, the interval between the two items of the sample sequence had a much smaller effect, or none at all (Experiment 2). These results support an account of response‐sequence differentiation that stresses short‐term memory of organized behavior patterns.
THE CONTRIBUTION OF AN ADDED COUNTER TO A FIXED‐RATIO SCHEDULE
Authors: Ferster C. B. , Peele David B.
Published: March 2006

Although previous research showed that a visual counter increased the rate of responding on a large fixed‐ratio schedule, a theoretical analysis of the factors responsible for fixed‐ratio performance suggests that the primary control by number of responses since reinforcement is to weaken the performance. The present experiment employed a multiple schedule in which the same fixed‐ratio value alternated with and without an added counter. It tested the hypothesis that the differential reinforcement of high‐rate responding masked the attenuation of the fixed‐ratio performance from the unoptimal discriminative control produced by the fixed relation between number of responses and reinforcement. In the present experiment the postreinforcement pause was consistently longer in the components with the added counter, while running rates remained comparable between the components of the multiple schedule. Both components of the multiple schedule involved differential reinforcement of high‐rate responding while only the components with the added counter amplified the discriminative control by number of pecks since reinforcement.
ACQUISITION AND MAINTENANCE OF TRUSTING BEHAVIOR
Authors: Hake Don F. , Schmid Tom L.
Published: March 2006

This study determined whether a two‐person exchange situation contained natural contingencies for trusting behavior or whether external contingencies were necessary. Pairs of college students worked matching‐to‐sample problems for money. On each trial there was one problem and the subjects determined which of them would solve it. Trusting behavior was defined as an increase in the number of consecutive problems each subject allowed his partner to work during sessions that also ended with an equitable distribution. Simply, trust was a temporary deviation from equity. A subject could give the problem to the other person (cooperate), or not respond and let the other person take the problem (share). Other possibilities were for both subjects to try to take the problem (complete), or for neither subject to respond and thereby let the person who worked the last problem also work the next one (passive trust). When only four lever pulls were required to distribute a problem (no external contingencies to reach either equity or trust) subjects reached equity, but only minimal trust (strict alternation of single problems) developed in 18 sessions. When 30 or 60 lever pulls were required to distribute a problem (smaller response requirement for passive trust and therefore a contingency for trust), trusting behavior developed after a few sessions (fixed ratio 30) or after several trials of the first session (fixed ratio 60) and it ordinarily expanded gradually to 10 to 15 consecutive problems through passive trust. The aversiveness of the inequity involved in trusting appears to necessitate a contingency for acquisition. Once trust develops, however, this aversiveness is reduced as subjects learn the inequity is only temporary (e.g., once trust was acquired at fixed ratio 60 it was maintained at fixed ratio 4, which would not initially produce it), and the direction of the inequity appears to become of questionable importance (e.g., being behind was alternated over rather than within sessions and usually not in a systematic manner).
ON THE EXPONENT IN THE “GENERALIZED” MATCHING EQUATION
Authors: Allen Craig M.
Published: March 2006

A power function equation between ratios of behavior and ratios of reinforcement rates has been called a generalized form of Herrnstein's (1961) matching law, even without a formal relationship having been shown between the two equations. The present work uses a functional relationship to prove that when ratios of reinforcement are not equivalent to ratios of behavior, and the transform leading to this inequality is consistent for every pair of reinforcement rates, the result is a power function relationship between response and reinforcement ratios. The label “generalized matching equation” for the power function equation is thus validated formally.
DELAY OR RATE OF FOOD DELIVERY AS A DETERMINER OF RESPONSE RATE
Authors: Shull Richard L. , Spear D. J. , Bryson Aloha E.
Published: March 2006

Pigeons were confronted with two keys: a green food key and a white changeover key. Food became available for a peck to the green key after variable intervals of time (mean = 113 seconds). A single peck on the changeover key changed the color of the food key to red for a fixed period of time during which the timing of the variable‐interval schedule in green was suspended and the switching option eliminated and after which the conditions associated with green were reinstated. In Experiment 1 a single food presentation was obtainable during each red‐key period after a minimum delay timed from the switch. This delay and the duration of the red‐key period were held constant during a condition but varied between conditions (delay = 2.5, 7.5, 15, or 30 seconds; red‐period duration = 30, 60, 120, 240, or 480 seconds). In Experiment 2 additional food presentations were scheduled during a 240‐second red‐key period with the delay to the first food delivery held constant at 30 seconds, and the delays to later food deliveries varied over conditions. Considering the data from both experiments, the rate of switching to red was a decreasing function of the delay to the first food, the delay to the second food, and perhaps the delay to the third food after a switch. There was no clear evidence that the rate of food in the red‐key period made an independent contribution. The ordering of response rates among conditions was consistent with the view that each food presentation after a response adds an incremental effect to the rate of the response and that each food presentation's contribution is a decreasing function of its delay timed from the response.