bluuebunny/crossref_metadata_2025 huggingface dataset:
THE EFFECTS OF AMOUNT OF TRAINING PER REVERSAL ON SUCCESSIVE REVERSALS OF A COLOR DISCRIMINATION
Authors: Beale I. L.
Published: March 2006

Three groups of pigeons were trained on a red‐green discrimination in which the stimuli were alternately presented in a multiple schedule of reinforcement. The discrimination was reversed 24 times. Groups were given 1, 2, or 4 hr of training on each discrimination. Increasing the length of training had two principal effects on reversal performance: it increased the rate of extinction of responding to one of the stimuli and increased the rate of reacquisition of responding to the other. The latter effect involved both an increase in reacquisition of responding to a positive stimulus within reversals and an increase in recovery of responding to the previous negative stimulus between reversals. Improvements in performance of each group over the series of reversals were qualitatively similar to the two effects of length of training on each discrimination, and were analogous to effects obtained in other studies involving overtraining and successive reversals of simultaneous discriminations.
INTERRESPONSE TIME DURATION IN FIXED‐INTERVAL SCHEDULES OF REINFORCEMENT: CONTROL BY ORDINAL POSITION AND TIME SINCE REINFORCEMENT1
Authors: Shull Richard L. , Brownstein Aaron J.
Published: March 2006

The times between each of the first thirteen responses after reinforcement (the first twelve interresponse times) were determined for two pigeons whose pecking was reinforced on fixed‐interval schedules of food reinforcement ranging from 0.5 min to 5 min. These interresponse times were classified with respect to their ordinal position in the sequence of responses and with respect to the time since the preceding reinforcement at which the initiating response occurred. The median interresponse time durations were essentially constant after the sixth response after reinforcement regardless of the time at which the interresponse time was initiated. The durations of the first few interresponse times after reinforcement decreased as the number of preceding responses increased and as the time since the preceding reinforcement increased.
FACTORS INFLUENCING INHIBITORY STIMULUS CONTROL: DIFFERENTIAL REINFORCEMENT OF OTHER BEHAVIOR DURING DISCRIMINATION TRAINING1
Authors: Weisman R. G.
Published: March 2006

Pigeons were trained to respond on a multiple variable‐interval 1‐min variable‐interval 1‐min schedule, then switched to a multiple variable‐interval 1‐min differential‐reinforcement‐of‐other‐behavior discrimination training. The rate of reinforcement was held constant during the shift from non‐differential reinforcement to discrimination training. Behavioral contrast and post‐discrimination inhibitory stimulus control followed the observation of a reduction in the rate of responding to the stimulus correlated with reinforcement for the non‐occurrence of pecking.
APPARENT MOVEMENT DETECTION IN THE PIGEON1
Authors: Siegel R. K.
Published: March 2006

Pigeons were trained to discriminate between the presence and absence of apparent movement in visual displays. Generalization gradients obtained on the dimension of speed indicated a broad range of movement detection. Extremely accurate discrimination performance on displays varying in direction of movement suggested formation of a “movement concept”.
UNBIASED AND UNNOTICED VERBAL CONDITIONING: THE DOUBLE AGENT ROBOT PROCEDURE1
Authors: Rosenfeld Howard M. , Baer Donald M.
Published: March 2006

Subjects who were told they were “experimenters” attempted to reinforce fluent speech in a supposed subject with whom they spoke via intercom. The supposed subject was to say nouns, one at a time, on request by the “experimenter”, who reinforced fluent pronunciation with points. Actually, the “experimenter” was talking to a multi‐track tape recording, one track of which contained fluently spoken nouns, the other track containing disfluently spoken nouns. If the “experimenter's” request for the next noun was in a specified form a word from the fluent track was played to him as reinforcement; requests in any other form produced the word from the disfluent track. Repeated conditioning of specific forms of requests was accomplished with two subject‐“experimenters,” who were unable to describe changes in their own behavior, or the contingencies applied. This technique improved upon an earlier method that had yielded similar results, but was less thoroughly controlled against possible human bias.
SOME EFFECTS OF PUNISHMENT SHOCK INTENSITY UPON DISCRIMINATIVE RESPONDING
Authors: Powell Robert W.
Published: March 2006

Three pigeons received visual discrimination training under both multiple variable‐ratio extinction and variable‐interval extinction schedules. All birds developed nearly perfect discrimination. When punishment for every tenth response during food reinforcement was presented, responding decreased as shock intensity increased. At the same time, responding during extinction, which was not punished, increased at intermediate punishment intensities, but returned to low levels under severe punishment. A second procedure, in which punishment and no‐punishment sessions alternated unsystematically, was employed with two of the birds. The results under this procedure essentially replicated the data obtained as punishment shock intensity increased gradually.
A RAPID AUTOMATIC TECHNIQUE FOR GENERATING OPERANT KEY‐PRESS BEHAVIOR IN RATS
Authors: Davidson Arnold B. , Davis Dixon J. , Cook Leonard
Published: March 2006

Experimentally naive rats were trained to key press on a fixed‐ratio 10 schedule of food reinforcement by a completely automatic procedure within a single, 1‐hr session. Control procedures demonstrated that the resulting behavior was an operant, under control of the schedule of reinforcement and the specified reinforcing stimulus (food). A simple, combination food‐tray operandum, also described, was used as the basis for the training technique.
EFFECTS OF LONG‐TERM SHOCK AND ASSOCIATED STIMULI ON AGGRESSIVE AND MANUAL RESPONSES1
Authors: Hutchinson R. R. , Renfrew J. W. , Young G. A.
Published: March 2006

Squirrel monkeys were exposed to response‐independent, fixed‐frequency shock that produced biting attack upon a pneumatic hose. Attacks decreased within and across sessions at low intensities and high frequencies of shock, but increased within and across sessions at higher intensities and lower shock frequencies. Stimuli paired with shock, when presented alone, came to produce biting, and stimuli correlated with shock parameters that produced increases in responding within sessions produced similar increases when presented alone. Further experiments showed that continuing exposure to shock also produced lever pressing or chain pulling, with longer shock exposure again producing higher response rates. Whereas biting generally decreased throughout the intershock interval, manual responding generally increased as shock time approached, but immediately before shock was often suppressed. Following shock, biting attack predominated over manual behavior. The results suggest a possible explanation for the extreme resistance of avoidance behavior to extinction, and may also partially explain the persistence of responding during schedules of response‐produced shock. Relationships of the present findings to naturalistic observations of relations between fleeing, freezing, and fighting performances are discussed.
SECOND‐ORDER OPTIONAL AVOIDANCE AS A FUNCTION OF FIXED‐RATIO REQUIREMENTS
Authors: Krasnegor Norman A. , Brady Joseph V. , Findley Jack D.
Published: March 2006

Two rhesus monkeys responded on a fixed‐ratio schedule in Stimulus 1 (blue light) to avoid the onset of Stimulus 2 (green light). Failure to avoid Stimulus 2 required a second fixed‐ratio performance to avoid Stimulus 3 (red light) in the presence of which unavoidable shock occurred. Relative frequencies of avoidance performance in the blue light and in the green light were inversely related to the ratio requirement under each stimulus condition. Both differential response‐cost and avoidance‐failure probability factors were related to the observed changes.
MEASURING FLICKER THRESHOLDS IN THE BUDGERIGAR1
Authors: Ginsburg Norman , Nilsson Virginia
Published: March 2006

A method of measuring thresholds in animals is described and illustrated in the case of flicker fusion in the budgerigar. After training with reinforcement for pecking at a high‐frequency light (115 Hz) and nonreinforcement for pecking at a low‐frequency light (20 Hz), subjects were given threshold trials and reinforcement trials mixed randomly in equal number. In threshold trials (no reinforcement), the target began flashing at 115 Hz and decreased in flash rate with each peck until the subject stopped responding. During reinforcement trials, the target continued to flash at 115 Hz, and responses were reinforced on a variable‐ratio schedule. Flicker thresholds obtained from two birds showed a linear relation to the logarithm of intensity in accordance with the Ferry‐Porter law.
THE EFFECTS OF BRIEF STIMULI PRESENTED UNDER A MULTIPLE SCHEDULE OF SECOND‐ORDER SCHEDULES
Authors: Lorge John de
Published: March 2006

The effects of briefly presented stimuli paired or not paired with food reinforcement were investigated in the pigeon on a multiple schedule containing second‐order schedules. A stimulus paired with food reinforcement was presented on a variable‐interval schedule in one unit of the multiple schedule and either a stimulus not paired with food reinforcement or no stimuli were scheduled in the other unit. Response rates were highest when behavior was followed by the food‐paired stimulus. Presentation of the food‐paired stimulus at completion of each 1‐min variable‐interval component maintained a steady rate of responding between consecutive food presentations. Pausing following food reinforcement was greatest in the second‐order schedule not containing the paired stimulus. Reversing the stimulus pairings led to a reversal of the relative response rates and patterns of responding for each stimulus.
ELICITATION AND PUNISHMENT OF INTRASPECIES AGGRESSION BY THE SAME STIMULUS1
Authors: Roberts Carl L. , Blase Karen
Published: March 2006

Fighting responses were elicited in pairs of rats by shocks over a period of 46 days. During certain blocks of these days, “punishing” shocks were made contingent on the shock‐elicited fights. Fighting frequency was reduced as a direct function of the intensity of the contingent shocks. Fighting frequency recovered completely when contingent shocks were removed.
OBSERVING RESPONSES AND INFORMATIVE STIMULI1
Authors: Wilton R. N. , Clements R. O.
Published: March 2006

Pigeons were trained on a trial procedure. A trial began with the illumination of a pecking key by a white light. After a fixed interval, a key peck could turn the key to one of two equi‐probable colors and produce a delayed trial outcome—an equi‐probable occurrence of either reinforcement or nonreinforcement. After a trial, the key turned dark and the trial ended. The response could be made into an observing response by correlating the key colors with the outcomes. Response rates in the fixed interval then increased to a level greater than when the colors and outcomes were uncorrelated. In another phase, the response produced only the colors. The trial outcomes occurred some seconds after the fixed interval without a response being required. Correlating the colors with the outcomes again increased response rates. In a second experiment, a further condition was added in which reinforcement was the outcome on every trial. Response rates were lower than when there were equi‐probable reinforcement and nonreinforcement outcomes with correlated colors, and about the same as when there were equi‐probable outcomes with uncorrelated colors. The results suggest that stimuli providing information about the probability of reinforcement are themselves reinforcing.
MATCHING TO RELATIVE REINFORCEMENT FREQUENCY IN MULTIPLE SCHEDULES WITH A SHORT COMPONENT DURATION1
Authors: Shimp Charles P. , Wheatley Kimbal L.
Published: March 2006

Three pigeons performed on two‐component multiple variable‐interval variable‐interval schedules of reinforcement. There were two independent variables: component duration and the relative frequency of reinforcement in a component. The component duration, which was always the same in both components, was varied over experimental conditions from 2 to 180 sec. Over these conditions, the relative frequency of reinforcement in a component was either 0.2 or 0.8 (±0.03). As the component duration was shortened, the relative frequency of responding in a component approached a value equal to the relative frequency of reinforcement in that component. When the relative frequency of reinforcement was varied over conditions in which the component duration was fixed at 5 sec, the relative frequency of responding in a component closely approximated the relative frequency of reinforcement in that component. That is, the familiar matching relationship, obtained previously only with concurrent schedules, was obtained in multiple schedules with a short component duration.
CONCURRENT SCHEDULES OF RESPONSE‐INDEPENDENT REINFORCEMENT: DURATION OF A REINFORCING STIMULUS
Authors: Brownstein Aaron J.
Published: March 2006

Presentations of grain to three pigeons were determined by two response‐independent schedules. Interpresentation intervals varied with a mean interval of 1.5 min for each schedule. Both were concurrently operative, but grain was presented by one only when the chamber was illuminated with blue light and by the other only during amber illumination. A response on a white key, the only key in the chamber, alternated the stimulus conditions and the effective schedule. Grain presentation durations associated with the illumination conditions were varied from 1.5 to 4.5 sec. The proportion of the total session time spent in an illumination condition closely approximated the relative grain presentation duration provided in that illumination. For two of the birds, the proportion of the total number of grain presentations obtained in an illumination condition was an increasng function of the presentation duration in that illumination.
AUTOMATED PREFERENCE TESTING APPARATUS FOR RATING PALATABILITY OF FOODS1
Authors: Thompson R. D. , Grant C. V.
Published: March 2006

An electronic preference testing apparatus is described for measuring taste preference of rodents and other small animals with solid or liquid foods. The apparatus is designed on the principle of the two‐choice, preference technique. It operates photoelectrically with a sequence of presentations so that whenever a subject eats from a compartmentalized food tray, a standard and a test food are each briefly sampled alone before both foods are presented together (in alternate positions) for preference determination. Preferences are automatically recorded on digital counters. The apparatus is built in two modules (a preference tester and the master control) connected by multiconductor cable. The modular design provides portability and isolation of the animals from the major noise‐producing components. Diagrams of the apparatus are given, and test results from a trial that evaluated positional bias and a sucrose‐concentration preference experiment are presented to demonstrate its application in research.
SEQUENTIAL PATTERNS IN POST‐REINFORCEMENT PAUSES ON FIXED‐INTERVAL SCHEDULES OF FOOD1
Authors: Shull Richard L.
Published: March 2006

Responding by one pigeon was reinforced with food on fixed‐interval schedules of 30, 60, and 300 sec duration. A second pigeon was studied under fixed‐interval durations of 60 and 300 sec. For both birds, the average post‐reinforcement pause was one‐half the duration of the fixed interval. Autocorrelation coefficients revealed first‐order sequential dependencies in series of post‐reinforcement pauses. On the 300‐sec fixed‐interval schedule, successive post‐reinforcement tended to alternate between long and short durations. At the shorter fixed‐interval durations there was less evidence of alternation sequences. A second experiment was conducted to determine if the time intervals between the first response after reinforcement and the next reinforcement (the work periods) were responsible for the alternation patterns in the series of post‐reinforcement pauses. To evaluate the role of the work period, several procedures were used to modify the work period from that obtained on the fixed‐interval 300‐sec schedule. Adding a schedule to the fixed‐interval schedule that set the minimum amount of time that could elapse between the first response after reinforcement and the next reinforcement eliminated the alternation pattern. Control schedules indicated that the elimination of alternation patterns resulted from constraints on the work period per se and not from confounded changes in the interreinforcement intervals.
RATE CHANGES AFTER UNSCHEDULED OMISSION AND PRESENTATION OF REINFORCEMENT
Authors: Zimmerman Donald W.
Published: March 2006

Changes in response rate similar to frustration effects were studied in a two‐lever situation. Responding on one lever on a fixed‐interval schedule produced access to water for 5 sec and an exteroceptive stimulus. In the presence of this stimulus, responding on another lever on a fixed‐interval schedule produced access to water for 5 sec and terminated the stimulus. Occasional omission of a previously scheduled reinforcer after responding on the first lever resulted consistently in increases in rate on the second lever during the immediately succeeding interval. In another procedure, occasional presentation of a previously unscheduled reinforcer after responding on the first lever resulted consistently in decreases in rate on the second lever during the immediately succeeding interval. Changes occurred after the first omissions or presentations and were about the same in magnitude as the procedure continued over several sessions. Typically, an increase or decrease in rate was maintained throughout an entire 100‐sec interval. Changes in rate on the second lever of approximately the same magnitude also occurred when rate on the first lever was near‐zero under a schedule that differentially reinforced behavior other than lever pressing.
CONTRAST AND INDUCTION IN RATS ON MULTIPLE SCHEDULES1
Authors: Pear Joseph J. , Wilkie Donald M.
Published: March 2006

Eight rats were trained on a variable‐interval schedule in the presence of a light (Phase I). Responding was then extinguished in the presence of darkness that alternated with the light (Phase II). Reinforcement was then introduced in the presence of darkness (Phase III). Several rats were then returned to the condition of Phase II (Phase IV) and then to that of Phase III (Phase V). The responding of most rats showed clear behavioral contrast in Phase II–i.e., an increase in responding in the presence of the light. When, for three rats, Phase III was introduced early after the occurrence of positive contrast, either positive induction occurred, i.e., an increase in responding in the presence of the light, or there was little change. Negative contrast did not occur. It was further shown that positive contrast dissipates over time, thus replicating a result previously obtained with pigeons and that the positive induction effect seems also to dissipate over time. The introduction of reinforcement in the presence of darkness (Phases III and V) after the dissipation of positive contrast seemed to have little consistent effect.
SECOND‐ORDER SCHEDULES WITH FIXED‐RATIO COMPONENTS: VARIATION OF COMPONENT SIZE1
Authors: Lee Julia K. , Gollub Lewis R.
Published: March 2006

Key pecking by pigeons was reinforced with food under second‐order schedules with fixedratio units. A constant total number of key pecks was required for reinforcement under each condition, but the size and, inversely, number of fixed‐ratio components were varied. The total response requirement of 256 pecks was divided into fixed‐ratio units of 128, 64, 32, 8, and 2 responses. A brief stimulus, which always preceded food reinforcement, was presented upon completion of each fixed‐ratio unit. Under most conditions, the pattern of within‐unit responding was typical of that under simple fixed‐ratio schedules. Overall response rate was an inverted U‐shaped function of component size. That is, response rates were highest under moderate sized units (fixed ratio 128 and 64). This relationship is consistent with previous determinations of rate as a function of fixed‐ratio value for simple fixed‐ratio schedules.
STIMULUS FUNCTIONS IN SOME CHAINED FIXED‐RATIO SCHEDULES OF REINFORCEMENT1
Authors: Sheldon M. H.
Published: March 2006

For two pigeons, behavior was compared in equivalent two‐link chained and tandem schedules in which 100 responses were required for food reinforcement but the responses required in the two links of the chained schedule were varied over the values 2–98, 50–50, and 98–2. Initial pausing, response rate in each link, and the total time to complete each ratio were recorded. In chained components, initial‐link pausing (for both birds) and total time to complete the ratio (for one bird) were generally shorter when the response requirement was 2–98 than when it was 50–50 or 98–2; for terminal‐link pausing this relationship was reversed for both birds. There were also systematic changes in behavior in tandem components, and in the relationship between behavior in chained and tandem components. The results are discussed in terms of conditioned reinforcement.
EFFECT OF DELAY‐INTERVAL ILLUMINATION ON MATCHING BEHAVIOR IN THE CAPUCHIN MONKEY1
Authors: D'Amato M. R. , O'Neill Ward
Published: March 2006

Experiment 1 demonstrated that delayed matching‐to‐sample in the capuchin monkey was superior when the delay interval was spent in darkness rather than in moderate illumination. In contrast with previous studies in which the delayed‐matching ability of primates appeared limited to 60 sec or less, in the dark condition all subjects showed above‐chance matching at a 120‐sec delay interval. Experiment 2 verified that darkness during the delay interval can facilitate delayed matching and provided evidence that the effective variable was the illumination level of the delay interval rather than change in illumination, which in Exp. 1 was confounded with illumination level.
TEACHING SERIAL POSITION SEQUENCES TO MONKEYS WITH A DELAYED MATCHING‐TO‐SAMPLE PROCEDURE1
Authors: Mackay Harry A. , Brown Stephen M.
Published: March 2006

Comparison was made of two methods for training monkeys to “observe” a two‐member serial position sequence by pressing two consecutively lighted keys and then to “report” the sequence by pressing the same two keys in the same order but without the lights. A fading technique involving gradual elimination of brightness cues from “reporting” keys was found more effective than a no‐fading procedure in which the cues remained bright during training and then were suddenly removed. Animals that failed to learn to report a new sequence with the no‐fading procedure sometimes developed behavior incompatible with that desired. They made repeated and specific errors that prematurely terminated trials of the sequence to‐be‐learned, even though the correct key was cued by a bright light. They behaved appropriately, however, on succeeding trials of other sequences. Thus, the errors were followed by trials on which reinforcement occurred. Manipulation of this contingency indicated its importance in maintaining the stereotyped error patterns.
TESTING FOR INHIBITORY STIMULUS CONTROL WITH S− SUPERIMPOSED ON S+1
Authors: Davis J. Michael
Published: March 2006

Pigeons learned a successive discrimination between a positive stimulus (red) correlated with a variable‐interval 1‐min reinforcement schedule and a negative stimulus (vertical line) correlated with either a variable‐interval 5‐min schedule or extinction. Transfer tests measured the rate of responding to the positive stimulus alone, to various orientations of the negative stimulus, and to the same line orientations superimposed on the positive stimulus. Although there were no gradients with minima at the training value for the negative stimulus dimension, the addition of the negative stimulus dimension to the positive stimulus always resulted in a lower response rate than that for the positive stimulus alone. The results demonstrate that an operational definition of inhibitory stimulus control that requires increased responding to stimuli more distant from a negative stimulus (along some dimension) is not always consistent with a definition that requires the suppression of responding in the presence of one stimulus, the positive stimulus, by the simultaneous presentation of another, the negative stimulus.
CONTROL OF RESPONDING BY LOCATION OF AUDITORY STIMULI: RAPID ACQUISITION IN MONKEY AND RAT1
Authors: Harrison J. M. , Downey P. , Segal M. , Howe M.
Published: March 2006

Monkeys require a considerably larger number of trials to bring responding under the control of the location of an auditory stimulus than cats, rats, and bats with the same experimental procedures. The present experiment sought to determine the conditions necessary for rapid acquisition of control of responding by location of noise and tone bursts in the monkey. Monkeys were run in an enclosure that contained four loudspeakers and four manipulanda. Two conditions were used in training. In the adjacent condition, a stimulus (noise or tone burst) was presented through one or other of two speakers and a response on the manipulandum adjacent to the speaker was reinforced with food. In the nonadjacent condition, a stimulus was presented through one of two speakers and a response on a manipulandum remote from the speaker was reinforced with food. Acquisition of control was measured by change in the percentage of reinforced responses during training. In the adjacent condition, responding came under control of location within zero to three sessions. In nonadjacent conditions, the animals required 14 to 20 sessions to come under control of location. These latter numbers are comparable to those reported in the literature for localization discrimination in monkeys.
DISCRIMINATION TRAINING AND STIMULUS COMPOUNDING: CONSIDERATION OF NON‐REINFORCEMENT AND RESPONSE DIFFERENTIATION CONSEQUENCES OF SΔ1
Authors: Weiss Stanley J.
Published: March 2006

In Exp. 1, four rats were trained on a two‐component multiple schedule with tone and light each associated with different variable‐interval schedules. Extinction in light‐out no‐tone, common to previous studies reporting additive summation to compounded discriminative stimuli, was omitted from training. In testing, the simultaneous presentation of tone and light controlled a response rate intermediate between that controlled by these stimuli presented singly. In Exp. 2, animals were trained on three‐ply multiple schedules. While tone and light were each associated with variable‐interval schedules for both groups, light‐out no‐tone signalled extinction for one and differential‐reinforcement‐of‐behavior‐other‐than‐bar‐pressing for the other. This permitted response reduction during light‐out no‐tone to be viewed independently of non‐reinforcement. Responding of both groups showed summation to tone plus light in testing, with the effect clearly larger for extinction‐trained subjects. These experiments indicate that: (1) discrimination training afforded by extinction has been integral to additive summation previously reported, (2) response differentiation and non‐reinforcement consequences of extinction training contribute to the magnitude of summation, and (3) summation and peak shift might be functionally related phenomena.
TAKING AND THE DISRUPTION OF COOPERATION1
Authors: Schmitt David R. , Marwell Gerald
Published: March 2006

Subjects could either cooperate or respond on a lower‐paying individual task. In Exp. I and II, either subject could make a response that took $1.00 of the other's earnings whenever subjects chose to cooperate. The two experiments differed as to whether taking responses were effective continuously or intermittently. Both experiments showed that the opportunity to take disrupted cooperative behavior. Experiment III indicated that if taking was possible regardless of whether the subjects cooperated or responded on the individual task, subjects either cooperated or terminated the experiment.
FACILITATION OF FOOD‐REINFORCED RESPONDING BY A SIGNAL FOR RESPONSE‐INDEPENDENT FOOD1
Authors: LoLordo Vincent M.
Published: March 2006

Five pigeons whose key pecking was maintained by 4‐sec access to grain on a variable‐interval 2‐min schedule received Pavlovian differential conditioning trials superimposed upon the instrumental baseline. The conditioned stimuli were changes in the stimulus on the key from white to red, or to a white horizontal line against a dark background. The positive conditioned stimulus was 20 sec long, and was followed immediately by 8‐sec access to grain. The negative conditioned stimulus, also 20 sec long, was never paired with response‐independent food. All pigeons responded more rapidly in the presence of the positive conditioned stimulus than in the presence of the negative one. The positive conditioned stimulus produced an increase in response rate over the pre‐conditioned stimulus period. The negative conditioned stimulus had no marked effect upon response rate. When the roles of the positive and negative stimuli were reversed, and the duration of the response‐independent reinforcement was reduced to 4 sec, the new positive conditioned stimulus came to facilitate responding, and the new negative conditioned stimulus no longer produced facilitation. A second discrimination reversal produced similar outcomes. When a third reversal was initiated, and the duration of response‐independent reinforcement was reduced to 2 sec, the difference between the effects of the positive and negative stimuli diminished.
COLOR‐NAMING FUNCTIONS FOR THE PIGEON1
Authors: Wright Anthony A. , Cumming William W.
Published: March 2006

Six pigeons were trained to match wavelengths in a three‐key matching‐to‐sample paradigm. Test trials were occasionally presented, where probe wavelengths appeared on the center key and choices were made to the training stimuli presented on the side keys. Color naming functions were obtained by plotting the percentage of test trials that each training stimulus wavelength was chosen for each center key probe wavelength. The wavelength where the functions intersected was interpreted as a transition point between pigeon hues. Three experiments employed different wavelengths as training stimuli. The first two experiments demonstrated that the intersection of the color‐naming functions occurred in all cases at 540 nm and 595 nm. The third experiment employed 540 nm and 595 nm as two of the three training stimuli, and the relatively slow acquisition, together with the resulting color‐naming functions, supported the proposition that 540 nm and 595 nm may be transition point wavelengths between pigeon hues.
PEAK SHIFT IN CONCURRENT SCHEDULES1
Authors: Winton A. S. W. , Beale I. L.
Published: March 2006

Pigeons were exposed to two keys, a main key and a changeover key. Initially non‐differential training was given in which pecking the main key was reinforced on a variable‐interval 2‐min schedule when the key displayed the first stimulus, a black line on a blue background, and was reinforced on an identical but independent variable‐interval 2‐min schedule when the key displayed a plain blue stimulus. Later, differential training was given in which pecking the main key was reinforced on a variable‐interval 2‐min schedule when the first stimulus was displayed; and was reinforced on a variable‐interval 10‐min schedule when a second stimulus, a black line of another orientation on a blue background, was displayed. During non‐differential and differential training, each peck on the changeover key changed the stimulus on the main key. Generalization tests were given before and after the differential training. These consisted of presentations on the main key of seven orientations of the black line on the blue background, including the first and second stimuli, with no reinforcements being given. Changeover‐key pecks changed the stimuli on the main key. Generalization gradients were obtained using three measures: time spent, responses, and response rate in the presence of each test stimulus. Typically, maximum values on these measures occurred to stimuli away from the first in a direction opposite the second stimulus, and minimum values occurred to stimuli away from the second in a direction opposite the first.
CHAINED AND TANDEM FIXED‐INTERVAL SCHEDULES OF PUNISHMENT1
Authors: Silverman Philip J.
Published: March 2006

Pigeons' key pecks were both punished with electric shock on four‐component chained and tandem fixed‐interval schedules and reinforced on a variable‐interval schedule of food presentation. Pecking was suppressed less in the early components of the chained schedule than in the early components of the tandem schedule. Related multiple and mixed schedules of punishment were also presented; these schedules were identical to the chained and tandem schedules, respectively, except that components changed independently of responding. Similar effects were obtained, in that responding was suppressed in all components of the mixed schedule and only in the fourth component of the multiple schedule of punishment. The performances maintained on the chained and tandem schedules of punishment were generally symmetrical to those found in analogous chained and tandem schedules of food reinforcement.
AUDITORY GENERALIZATION GRADIENTS FOR RESPONSE LATENCY IN THE MONKEY1
Authors: Moody David B. , Stebbins William C. , Iglauer Carol
Published: March 2006

Two monkeys were trained to press and hold a response key in the presence of a light and to release it at the onset of a pure tone. Initially, all responses with latencies shorter than 1 sec were reinforced without regard to the frequency of the pure tone, and the intensity of the pure tone that resulted in equal latencies at each frequency was determined. The second stage of the experiment consisted of discrimination training, during which releases to one pure‐tone frequency (positive stimulus) were reinforced and releases to a second frequency (negative stimulus) were extinguished. Median latencies to the negative stimulus slowly increased as did the variability of the latency distribution for the negative stimulus. There was no evidence of a concurrent decrease in latencies to the positive stimulus indicative of behavioral contrast. The third part of the experiment consisted of determining maintained generalization gradients by increasing the number of nonreinforcement stimuli. The gradients that eventually resulted showed approximately equal latencies to all frequencies of the negative stimulus and shorter latencies to the positive stimulus frequency.
SUPPRESSION OF OPERANT VS CONSUMMATORY BEHAVIOR1
Authors: DeCosta M. Joseph , Ayres John J. B.
Published: March 2006

The magnitude and variability of conditioned suppression of bar pressing and dipper licking were compared. In two steady‐state experiments, suppression of bar pressing was more profound and more stable from day to day. The two measures of suppression were uncorrelated as indexed by Pearson product‐moment correlation coefficients computed for adjacent trials. Correlations within measures (internal consistency) were somewhat higher for the bar‐press system except when a high proportion of rats completely suppressed on one of the correlated trials. In a transient state experiment in which possible adventitious punishment of both response systems was eliminated, suppression of bar pressing was again more profound and considerably slower to extinguish.
THE REMOVAL AND RESTORATION OF STIMULUS CONTROL1
Authors: Stoddard L. T. , Sidman Murray
Published: March 2006

When a well‐learned circle versus ellipse discrimination was made impossibly difficult for the subjects (rhesus monkeys), the controlling stimulus‐response topographies were replaced by competing topographies. The identification of two training conditions sufficient to reinstate the original discrimination permitted the following inferences: the original controlling topography had merely decreased in probability of occurrence, whereas the “strength” of the stimulus‐response relation remained unchanged; discriminations along the apparently continuous circle‐ellipse dimension actually involved several distinct stimulus‐control topographies.
NON‐SPATIAL DELAYED ALTERNATION BY THE PIGEON1
Authors: Williams Ben A.
Published: March 2006

Pigeons were trained on a non‐spatial delayed alternation task in which the color not pecked on the previous trial was correct. When varying delays were interposed between trials, alternation accuracy decreased as a function of delay, but remained greater than chance with a 45‐sec delay. Successful alternation on the longer delays was accomplished without behavioral mediation of the delay intervals. Also, during initial testing when a position cue was available in addition to the color cue after incorrect trials, alternation accuracy was greater after a preceding incorrect trial than after a correct trial. When the position cue was removed, no differences occurred as a function of the outcome of the preceding trial.
DISCRETE‐TRIALS SPACED RESPONDING IN THE PIGEON: THE DEPENDENCE OF EFFICIENT PERFORMANCE ON THE AVAILABILITY OF A STIMULUS FOR COLLATERAL PECKING1
Authors: Schwartz Barry , Williams David R.
Published: March 2006

Four pigeons were exposed to a discrete‐trial schedule in which only responses spaced by at least 6 sec were reinforced. After 45, fifty‐trial sessions, they failed to meet the spacing requirement in over 90% of the trials. When an alternative, non‐contingent key (pecks on which had no consequence) was illuminated concurrently with the first key, the spacing performance of the three pigeons that pecked the non‐contingent key improved so that they were obtaining 75% of the possible reinforcers. These data demonstrated the importance of collateral behavior in mediating spaced performance. It was suggested that pigeons may successfully refrain from responding on the spacing procedure only when another stimulus correlated with reinforcement is available for pecking, and that the form that collateral behavior takes may, in general, be non‐arbitrary, and species dependent.
THE ROLE OF INFORMATION IN THE EMISSION OF OBSERVING RESPONSES: A TEST OF TWO HYPOTHESES1
Authors: Wilson R. N. , Clements R. O.
Published: March 2006

Pigeons were trained on a trial procedure in a Skinner box. Each trial began with a fixed‐interval schedule. Responding on this schedule produced a stimulus and a delayed trial outcome. The stimulus signalled whether the forthcoming outcome was reinforcement or nonreinforcement. Thus, the response was an observing response. When reinforcement was the outcome on 20% of the trials, response rates in the fixed interval were higher than when reinforcement was the outcome on 80% of the trials. This result is consistent with the hypothesis that observing responses are reinforced by the information associated with the stimulus signalling reinforcement. The result seems inconsistent with the hypothesis that observing responses are also reinforced by the information associated with the stimulus signalling nonreinforcement.
OBSERVING BEHAVIOR IN SQUIRREL MONKEYS UNDER A MULTIPLE SCHEDULE OF REINFORCEMENT AVAILABILITY1
Authors: Lorge John O. de , Clark Fogle C.
Published: March 2006

Observing behavior of two squirrel monkeys was examined under a multiple schedule of four components. Lever (observing) responses produced either a stimulus indicating the availability of food or another stimulus indicating food was not available. Key responses in the presence of the food‐available stimulus produced food on a continuous reinforcement schedule. In the absence of food‐available stimuli, responding on the key had no scheduled consequences. Observing responses produced food‐available stimuli according to three different random‐interval schedules with mean interstimulus availability times of 1, 2, and 4 min. In the fourth component of the multiple schedule (observing extinction) food‐available stimuli never occurred. Each component of the schedule was correlated with a distinctive auditory stimulus. Observing rates decreased with decreasing frequency of the food‐available stimulus. Observing rates during extinction continued decreasing when the brief stimulus indicating food unavailability was no longer produced by lever pressing. When the brief stimulus was reinstated response rates increased abruptly.
RAPID ACQUISITION OF AN AUDITORY LOCALIZATION DISCRIMINATION BY RATS1
Authors: Beecher M. D. , Harrison J. M.
Published: March 2006

Acquisition of a sound localization discrimination by rats was investigated. Two loudspeakers were located outside an experimental enclosure containing two levers and a dipper feeder. In the same‐side condition, responses on the lever nearest the sound‐producing speaker were reinforced. Animals in this condition acquired the discrimination rapidly, generally within the first session. In the opposite‐side condition, responses on the lever furthest from the sound‐producing speaker were reinforced. Acquisition for animals in this condition began below the chance level (50% correct responses) and took on the order of 10 sessions to approach the final, high level. The course of acquisition in both cases appeared to depend upon an initial tendency of rats to respond on the lever nearest the source of sound in this situation. The rise‐decay time of the 4‐kHz tone burst signal clearly affected the performance level reached. It did not, however, affect the rate at which the discrimination was acquired.
COMPOUND STIMULUS CONTROL BY DISCRIMINATIVE STIMULI ASSOCIATED WITH HIGH AND MODERATE RESPONSE RATES1
Authors: Adams Donald L. , Allen Joseph D.
Published: March 2006

Four rats received water on a fixed‐ratio schedule for lever pressing in the presence of a tone (or light) stimulus and on a variable‐interval schedule in the presence of a light (or tone) stimulus. Following stabilization of a high response rate during the fixed‐ratio component and a moderate response rate during the variable‐interval component, brief periods with the light and tone presented simultaneously but with no responses reinforced were inserted into the regular training schedule. Response rates during the compound stimuli were intermediate between the response rates controlled by the individual fixed‐ratio and variable‐interval associated stimuli.
SOME TEMPORAL PARAMETERS OF NON‐CONTINGENT REINFORCEMENT1
Authors: Lachter Gerald D.
Published: March 2006

In each baseline session, pigeons were exposed to a multiple schedule in which each of five distinctive stimuli was correlated with a different frequency of reinforcement. In one component, responses were reinforced with a probability of 0.10 (random‐ratio schedule); in the other four components, responses were reinforced with different scheduled temporal frequencies averaging 30 to 240 sec between reinforcements (random‐interval schedules). For periods lasting 30 sessions, contingent reinforcement was discontinued and reinforcement was presented independent of responding at irregular intervals averaging 30, 60, or 120 sec, while the sequence of stimuli continued. After each such period, the baseline was reinstated for 30 sessions. The data indicated that: (1) The rate of responding in the presence of all stimuli decreased as exposure to the non‐contingent reinforcement procedure was prolonged, at all the frequencies of reinforcement employed; (2) The rate under the random‐ratio schedule declined faster than the rates under all the random‐interval schedules, presumably because the decrease in reinforcement frequency under this stimulus condition was greatest; (3) The decline in rates of responding under the stimuli correlated with the random‐interval schedules tended to be greatest for the stimuli paired with the lowest frequencies of reinforcement.
OPERANT CONDITIONING IN THE BAT PHYLLOSTOMUS HASTATUS1,2
Authors: Beecher M. D.
Published: March 2006

Bats of the species Phyllostomus hastatus were trained to press a pigeon key with food as the reinforcer. Patterns of responding under fixed‐ratio, fixed‐interval, and variable‐interval schedules of reinforcement were similar to those typically shown by other species. In a simple auditory discrimination, responding readily came under stimulus control. It is suggested that the behavioral method could be applied to various problem areas of bat behavior.
FIXED‐RATIO REINFORCEMENT OF SPACED RESPONDING1
Authors: Bigelow George
Published: March 2006

Responses by rats were reinforced with food under a second‐order schedule involving fixed‐ratio reinforcement of temporally spaced responses. Requirements of 20, 8, and 3 responses were examined. The typical characteristic of spaced responding was maintained under the ratio schedules: interresponse time distributions were similar to those typically seen, and were not noticeably affected by the ratio value. Comparison of total response rate, correct response rate, and accuracy showed correct response rate to be the most consistently affected by changes in the ratio value. Substantial evidence of schedule control was seen only for correct responses. Incorrect response records were erratic, but rates generally declined as reinforcement was approached. Correct response records were characterized by increasing rate as reinforcement was approached. It was suggested that the pattern of fixed‐ratio performance revealed may be affected by the behavioral unit examined.
DELAYED REINFORCEMENT IN A MULTIPLE SCHEDULE1
Authors: Wilkie Donald M.
Published: March 2006

Three rats and a pigeon were first trained on a two‐component multiple schedule in which reinforcement in the two components occurred immediately after a response. Later, reinforcement in one component was delayed by a few seconds. During both stages of the experiment, reinforcement was scheduled by equal variable‐ (pigeon) or random‐interval (rats) schedules in the two components. The main effect of the delayed reinforcement was to increase the rate of responding in the unchanged (non‐delay) component. This behavioral contrast effect did not appear in all cases to be dependent upon a reduction in the rate of responding or the frequency of reinforcement in the delay component. This finding suggests that a reduction in response rate and/or reinforcement frequency in one component of a multiple schedule may not be a necessary prerequisite for the occurrence of behavioral contrast. This finding is, however, consistent with an explanation that suggests that behavioral contrast results from the introduction of a less‐preferred condition in one component of a multiple schedule, since it is known that animals “prefer” immediate to delayed reinforcement.