bluuebunny/crossref_metadata_2025 huggingface dataset:
MAINTAINED GENERALIZATION TESTING OF CONDITIONED SUPPRESSION1
Authors: Winograd Eugene
Published: March 2006

This study concerns the use of a multiple stimulus discrimination procedure for producing data on the generalization of conditioned suppression. Four rats were maintained on a variable interval schedule of milk reinforcement in the presence of five stimuli varying in auditory click rate. When response rates were stable, electric shock was regularly paired with the termination of one of the click stimuli. For two rats the shock was paired with the slowest click rate, and for two rats shock was paired with the fastest click rate. The VI schedule remained in effect. Plots of the relative rates of response to each of the five stimuli yielded concave gradients for both animals suppressed at the slowest click rate, and flat gradients with a sharp drop at the warning stimulus for both animals suppressed at the fastest click rate. When the warning stimuli were reversed for both pairs of subjects, both gradient forms were reproduced. The present procedure was contrasted with procedures used by other investigators.
A COMPUTER‐ORIENTED SYSTEM FOR HIGH‐SPEED RECORDING OF OPERANT BEHAVIOR1
Authors: III Herbert Barry , Kinnard William J. , Watzman Nathan , Buckley Joseph P.
Published: March 2006

A method is described by which large quantities of data, generated at high and variable rates from a large number of test boxes, are recorded on a single eight‐channel punched paper tape. The data, which include a record of the occurrence time of each event in 1/10‐sec units are in a compact form, suitable for conversion to standard Hollerith punched card codes and for decoding and summarizing by a large digital computer. Experience with the system has demonstrated a high degree of accuracy and reliability, and low operating cost.
DISCRIMINATION LEARNING AS A FUNCTION OF STIMULUS LOCATION ALONG AN AUDITORY INTENSITY CONTINUUM1
Authors: Sadowsky Stephen
Published: March 2006

Eight groups of rats were trained on an auditory intensity discrimination in which the discriminative stimuli were separated by 10 decibels (db). Four pairs of stimuli were selected from different regions along a 60 — 100 db (SPL) intensity continuum. Counterpart groups were trained on each stimulus pair, with the relative intensity positions of the reinforced stimulus (SD) and the non‐reinforced stimulus (SΔ) reversed for the two groups. Discrimination acquisition curves were compared to determine whether stimuli separated by equal logarithmic units were of comparable “difficulty”, and to determine the relative effectiveness of an SD serving as the more versus less intense member of a stimulus pair. It was concluded that: (1) When SD is the more intense, auditory intensities of constant logarithmic separation are graded in “difficulty” along the intensity continuum; high intensity discriminative stimuli are most readily discriminated. When SΔ is the more intense, this graded effect is not evident. (2) For a given continuum location, discrimination is inferior when SΔ is the more intense. This effect is most pronounced at the high intensity end of the continuum and is chiefly attributable to differences in the rate of SΔ responding.
AN ANALYSIS OF CONTRAST EFFECTS IN MULTIPLE SCHEDULES1
Authors: Nevin John A. , Shettleworth Sara J.
Published: March 2006

Some phenomena of behavioral contrast in multiple schedules are reviewed, and three accounts of contrast are considered. Rate changes within a constant schedule component (transient contrasts) are distinguished from rate changes across successive schedule cycles (sustained contrasts). Pigeons were exposed to a three‐component multiple schedule, in which a stimulus correlated with a constant variable interval schedule of reinforcement was preceded by a stimulus correlated with more frequent variable interval reinforcement, or by an extinction stimulus. If the preceding stimulus was correlated with more frequent reinforcement, the response rate in the constant component was low and increased with time. If the preceding stimulus was correlated with extinction, the rate in the constant component was high and decreased with time. Similar transient contrasts were observed in a two‐component multiple schedule with different variable interval schedules in the two components. The transient contrast effects in the three‐component schedule were shown to depend on differential reinforcement frequency rather than differential response rate in the preceding component. Such transient contrasts were not sufficient to account for sustained contrast effects observed in these experiments. The relation of these findings to the concepts of excitation and inhibition is discussed.
CONCURRENT SCHEDULES OF INTERRESPONSE TIME REINFORCEMENT: PROBABILITY OF REINFORCEMENT AND THE LOWER BOUNDS OF THE REINFORCED INTERRESPONSE TIME INTERVALS1
Authors: Malott Richard W. , Cumming William W.
Published: March 2006

Data were obtained with rats on the effects of interresponse time contingent reinforcement of the lever press response using schedules in which interresponse times falling within either of two temporal intervals could be reinforced. Some of the findings were (a) the mode of the interresponse time distribution generally occurred near the first lower bound when the maximum reinforcement rate for the two lower bounds was equal; this also frequently occurred even when the reinforcement rate was less for the first lower bound; (b) as is the case with schedules using a single interval of reinforced interresponse times the values of the lower bounds partially determined the location and spread of the distributions; but the particular pair of values used did not seem to influence the effects of the probabilities of reinforcement; (c) although the modal interresponse time was usually at the lower bound of one of the two intervals of reinforced interresponse times, no simple relation existed between either the probability or rate of reinforcement of interresponse times in these two intervals and the location of this mode.
THE ROLE OF DISCRIMINATION TRAINING IN THE GENERALIZATION OF PUNISHMENT1
Authors: Honig Werner K.
Published: March 2006

Pigeons were trained to respond equally to various orientations of three parallel lines projected on a response key. One group was then punished for responding to the vertical lines, but not punished in a line‐absent condition. Two other groups were also punished but had no opportunity to make such a discrimination. Orderly generalization gradients were obtained from the discrimination group during recovery from punishment, with least responding to the vertical lines and higher rates to other orientations. Gradients obtained from the non‐discrimination groups were flat. A discrimination of punishment contingencies appears to be necessary for a stimulus correlated with punishment to acquire control over its reductive effects.
TRANSFER OF AN ESCAPE RESPONSE FROM TAIL SHOCK TO BRAIN‐STIMULATED ATTACK BEHAVIOR
Authors: Adams David , Flynn John P.
Published: March 2006

Nine cats, each with two hypothalamic electrodes in sites which when stimulated produced either quiet attack or attack accompanied by certain forms of vocalization, were trained to escape from tail shock by jumping onto a stool. They were then tested for transfer of the escape response to brain stimulation. Stimulation of the seven sites that yielded quiet biting attack did not elicit the learned response of jumping onto the stool. Stimulation of eight of the 11 sites that yielded attack accompanied by vocalization did elicit the learned response. It was concluded that attack behavior elicited by brain stimulation should not be considered a special case of the response to aversive stimulation, but that attack and response to aversive stimulation involve independent but overlapping systems.
NEGATIVE REINFORCEMENT AS SHOCK‐FREQUENCY REDUCTION1
Authors: Herrnstein R. J. , Hineline Phillip N.
Published: March 2006

Is a conditioned aversive stimulus necessary in avoidance conditioning? Or is a reduction in the rate of aversive stimulation alone sufficient to generate and maintain an avoidance response? Rats were subjected to an avoidance procedure in which shocks occurred randomly in time, but a response could reduce the overall rate of shock. Fifteen acquisition curves, obtained from 16 animals, showed both immediate and delayed, rapid and gradual increases in response rate; there was no representative acquisition curve. Response rates were directly related to the amount by which the response reduced shock frequency. In extinction, when shock rates were not affected by responding, the response total was inversely related to the amount by which the response had reduced shock frequency during prior conditioning, with as many as 20,000 extinction responses when the shock frequency reduction had been relatively small. Responding on this procedure shows that avoidance conditioning can occur without benefit of either classical exteroceptive stimuli or covert stimuli inferred from the temporal constancies of a procedure. It also shows that reduction in shock rate is alone sufficient to maintain avoidance.
STIMULUS GENERALIZATION: THE ORDERING AND SPACING OF TEST STIMULI1
Authors: Stevenson Joan G.
Published: March 2006

Twenty‐four pigeons learned a successive discrimination between 500 mμ (S+) and 574 mμ (S—). When tested in extinction, some birds received stimuli around S+, with no S— presentations. These birds showed a positive peak shift, with maximum responding not at 550 mμ, but displaced to 538 mμ and 544 mμ. Other birds were tested with stimuli around S—, with no S+ presentations. These birds showed a negative shift, with least responding not at 574 mμ, but at 586 mμ. Though the first group was tested around S+ and the second around S—, total responding between groups did not differ. When retested on the other half of the continuum, however, birds that had gone from the S+ half to the S— half responded fewer times than those that had gone from the S— half to the S+ half. In a second experiment, reducing stimulus spacing from 6 mμ, to 2 mμ produced flatter gradients and decreased the amount of positive shift. In a third experiment, birds were tested across the whole continuum with stimuli presented in serial order. A sequence from 538 mμ to 586 mμ produced no responding after the first part of the session; a sequence from 586 mμ to 538 mμ produced responding throughout the session.
PUNISHMENT OF AN EXTINGUISHING SHOCK‐AVOIDANCE RESPONSE BY TIME‐OUT FROM POSITIVE REINFORCEMENT1
Authors: Nigro M. R.
Published: March 2006

Two experiments were conducted to determine the effects of punishment by time‐out from positive reinforcement on the extinction of discriminated shock‐avoidance responding. Subjects were trained initially to bar press for food on an intermittent schedule of reinforcement and, concurrently, to avoid shock at the onset of a warning signal. Experiment I compared avoidance extinction performance under no punishment and when avoidance responding resulted in a 30‐sec TO from reinforced appetitive responding. In Exp II, the contingent use of TO punishment was compared with its random, or noncontingent use. The results of both experiments showed that in the absence of punishment, avoidance extinction was characterized by short latencies and nearly 100% avoidance responding. Avoidance responding in extinction was little affected by noncontingent TO punishment. When TO was made contingent upon avoidance responding, however, avoidance latencies immediately increased and the frequency of avoidance responses subsequently decreased to zero.
HUMAN, FREE‐OPERANT AVOIDANCE OF “TIME OUT” FROM MONETARY REINFORCEMENT1
Authors: Baron Alan , Kaufman Arnold
Published: March 2006

To assess the aversive effects of withdrawing monetary reinforcement, human subjects were exposed to a free‐operant avoidance procedure in which periods of no reinforcement occurred if the subject failed to respond, and each response postponed withdrawal of reinforcement. Avoidance behavior was developed either through specific instructions about the consequence of responding or through preliminary escape‐avoidance training. In all cases, rates of response were found to be a positively accelerated function of decreases in the duration by which responding postponed reinforcement withdrawal. The findings with respect to the function relating avoidance behavior to the interval of postponement were viewed as similar to those obtained when shock is used as the aversive event in free‐operant avoidance conditioning.
SOME EFFECTS ON GENERALIZATION GRADIENTS OF TANDEM SCHEDULES1
Authors: Yarczower Matthew , Dickson James F. , Gollub Lewis R.
Published: March 2006

The relationship between training conditions and stimulus generalization gradients was examined using tandem schedules of reinforcement. Schedules were selected so that frequency of reinforcement and rate of responding were varied somewhat independently of each other. A peak‐shift in the generalization gradient was obtained when extinction had been associated with one of the stimuli. No comparable peak shift was obtained when there were equal response rates in the training stimuli even with dissimilar frequencies of reinforcement. The data imply that response rates at the end of training, rather than reinforcement frequency per se, determine the characteristics of the generalization gradient.
STIMULUS FACTORS IN AVERSIVE CONTROLS: CONDITIONED SUPPRESSION AFTER EQUAL TRAINING TO TWO STIMULI1
Authors: Hoffman Howard S. , Selekman Warren L. , Fleshler Morton
Published: March 2006

Pigeons trained to peck a key for food were periodically presented with tones ending with electrical shock until tone presentation consistently suppressed ongoing pecks. Shock was then discontinued and gradients of stimulus generalization were assessed by presenting tones with frequencies above, below, and at the frequencies of those used to develop conditioned suppression. When the training tones had frequencies at 670 and 1500 cps, resulting gradients were bi‐modal with peak suppression at 670 and 1500 cps. Of the other test tones, 1000 cps produced the most suppression. When the training tones had frequencies at 450 and 2250 cps, bi‐modal gradients were again obtained with peak suppression to the 450 and 2250 cps tones. Of the other test tones, 1000 cps produced the least suppression. These results support the hypothesis that generalized response tendencies summate.
DISCRIMINATION AND EMISSION OF TEMPORAL INTERVALS BY PIGEONS1
Authors: Reynolds G. S.
Published: March 2006

Because the frequency distribution of IRTs showed little or no control by a DRL schedule, the schedule was modified so that the pigeon's behavior after each IRT would indicate whether or not it had discriminated the duration of the IRT. After every two pecks on a red key, the key changed to blue for 30 sec. Then it automatically became red again. Pecks on the blue key were reinforced with food on a VI schedule only when the preceding IRT on the red key had been longer than 18 sec. The birds did not selectively emit longer IRTs on the red key: the value of IRTs/op did not increase with IRT duration. However, they did discriminate the duration of the IRT emitted on the red key: the rate of pecking on the blue key was an increasing function of the duration of the preceding IRT on the red key.
PROBABILITY OF RESPONSE AND PROBABILITY OF REINFORCEMENT IN A RESPONSE‐DEFINED ANALOGUE OF AN INTERVAL SCHEDULE1
Authors: Millenson J. R.
Published: March 2006

Variable interval (VI) responding was hypothesized to be a function of differential reinforcement susceptibilities of various unspecified behavior chains that mediate interresponse times (IRTs). To test this hypothesis, probabilities of reinforcement were regulated for the lengths of chains of key pecking responses of pigeons, analogous to the way that VI regulates probabilities of reinforcement for IRTs. This procedure generated a number of VI‐like effects, supporting the notion that VI behavior can be construed as a special case of an interaction between the organism's function relating reinforcement susceptibilities to chain length and the experimenter's function relating probabilities of reinforcement to chain length.
SCHEDULES USING NOXIOUS STIMULI. II: LOW INTENSITY ELECTRIC SHOCK AS A DISCRIMINATIVE STIMULUS
Authors: McMillan D. E. , Morse W. H.
Published: March 2006

The presence or absence of pulses of low intensity electric shock was used as a discriminative stimulus to control responding under fixed ratio reinforcement in the squirrel monkey. Initially brief periods of non‐reinforcement were lengthened only when discriminative control was evident. Discriminative control was studied by (1) varying the duration of non‐reinforcement periods; (2) reversing the stimulus conditions correlated with reinforcement and non‐reinforcement periods; and (3) determining the minimum shock intensity necessary to maintain discriminative control. Stimulus control was not reliably affected by d‐amphetamine, chlorpromazine, or morphine. The discriminative control by pulses of low intensity electric shock was similar to that by other discriminative stimuli, except that the control developed slowly and was better when the pulsing shock was correlated with reinforcement than when correlated with non‐reinforcement.
A RAT CHAMBER AND ELECTRODE PROCEDURE FOR AVOIDANCE CONDITIONING1
Authors: Azrin N. H. , Hopwood J. , Powell J.
Published: March 2006

A method was developed for studying the reactions of rats to aversive shock. The distinctive features were the design of the chamber and a method of restraint that allowed the use of surface electrodes to deliver the shock. Advantages of this method were: (1) accurate specification of the shock actually received by the rat; (2) elimination of all unauthorized escape or avoidance reactions; (3) elimination of the shock scramblers and floor grids required with foot‐shock; and, (4) rapid acquisition of performance under various avoidance procedures and various frequencies of shock delivery.
SOME STATISTICAL TREATMENTS COMPATIBLE WITH INDIVIDUAL ORGANISM METHODOLOGY
Authors: Revusky Samuel H.
Published: March 2006

Consider experimental treatments with consequences so irreversible that baseline performance cannot be recovered. The conventional method of assessing the effects of such treatments by statistical means involves separate experimental and control groups. An alternative proposed here is to administer the experimental treatment to each subject, one subject at a time and in a random order; whenever any subject receives the experimental treatment, those subjects which have not yet received it receive a control treatment. This procedure permits results significant at the one‐tailed 0.05 level to be obtained with four subjects; if a two‐group procedure evaluated by means of the U test is used, a minimum of six subjects is needed for the same significance level. More generally, the procedure permits equal sensitivity to any experimental effect with over 30% fewer subjects than a two‐group procedure. Extensions of the basic method are made to a variety of levels of the experimental treatment and to treatments without irreversible effects, and limitations of the method are discussed.
SOME EFFECTS OF FIXED‐INTERVAL DURATION ON RESPONSE RATE IN A TWO‐COMPONENT CHAIN SCHEDULE
Authors: Kendall Stephen B.
Published: March 2006

In Exp. I three pigeons were trained on a two‐component chain schedule. Responding on a 1‐min variable‐interval schedule in the initial component led to a sequence of two fixed‐interval schedules in the terminal component. The rate of reinforcement in the terminal component was kept constant while the values of the two fixed intervals were varied. Three combinations of fixed‐interval schedules were studied, FI 0.25, FI 1.75 (minutes) or FI 1.00, FI 1.00, or FI 1.75, FI 0.25. The rate for each subject declined in the initial component as the value of the first fixed interval was increased. Experiment II was conducted to assess the role of the second fixed‐interval schedule in the terminal component in determining the rate of responding in the initial component. For each chain schedule the rate of responding in the initial component was determined both with and without the second of the sequence of fixed intervals. In all three cases the rate of responding in the initial component decreased when the second fixed interval was removed. Increasing the first fixed interval in Exp. I had a greater effect on variable‐interval performance than did the removal of the second fixed interval in Exp. II.
THE REINFORCEMENT OF SHORT INTERRESPONSE TIMES1
Authors: Shimp Charles P.
Published: March 2006

Five contingencies were superimposed successively on a variable‐interval schedule of reinforcement. In each of the resulting conditions, a different short, interresponse time was reinforced and an interresponse‐time distribution was obtained from each of three pigeons. The lower bound of the reinforced interresponse times ranged from 0.3 to 2.4 sec. The resulting distributions were combined, according to a rationale based upon concurrent operants, induction, and a property of variable‐interval schedules, to describe the interresponse‐time distributions from a variable‐interval schedule.
SEVERAL METHODS FOR TEACHING SERIAL POSITION SEQUENCES TO MONKEYS1
Authors: Sidman Murray , Rosenberger Peter B.
Published: March 2006

Three keys were available for monkeys to press. The objective was to teach the animals to press the keys in sequences up to 10 members in length. With fading procedures, a light that cued the correct key at a given serial member of the sequence faded out slightly each time the animal selected it, and became slightly brighter after the animal made an error at that sequence member. The correct keys were faded out, starting from the end of the sequence and proceeding toward the beginning. With control procedures, the cue lights were turned off suddenly, rather than being faded gradually. In almost every instance, the animals learned a longer series of unlighted key positions with the fading procedures than they did when each key‐light was turned off suddenly. Also, requiring the animals to press a series of keys cued by lights before they could reach the sequence members they were to learn hampered them in learning the later serial members. By using several different sequences, it was possible to replicate these findings within the individual animal.
PUNISHMENT AND RATE OF POSITIVE REINFORCEMENT1
Authors: Holz William C.
Published: March 2006

This experiment investigated the effect of several punishment intensities on two responses maintained by contrasting rates of reinforcement. The responses were concurrently reinforced according to two different variable‐interval schedules. Because these schedules were independent of one another and programmed different rates of reinforcement, the two responses occurred at dissimilar rates. When responses were simultaneously suppressed by punishment, both rates were reduced proportionately until suppression was virtually complete. In other words, the per cent suppression resulting from punishment was independent of the rate at which the response was reinforced. Phenomena found in single‐response studies were duplicated here. Responding tended to increase both within and between punishment sessions at mild and moderate punishment intensities. Cessation of punishment led to a “compensatory” overshooting beyond the prepunished response rate.
DOUBLE DISCRIMINATION AVOIDANCE WITH A SINGLE STIMULUS1
Authors: Keehn J. D.
Published: March 2006

Four white rats were trained to avoid electric shocks by depressing a bar after the onset of a stimulus and releasing it after termination of the stimulus. All subjects acquired the behavior of holding the bar in the presence of the stimulus and releasing it in the absence of the stimulus, but one animal almost always required a “priming” shock. The others exhibited a high level of shock avoidance.
RESPONSE SUPPRESSION PRODUCED BY VESTIBULAR STIMULATION IN THE RAT1
Authors: Riccio David C. , Thach John S.
Published: March 2006

Seven rats were trained to stable performance levels on either Fixed Ratio 47, Variable Ratio 47, Variable Interval 1‐min, or Fixed Interval 1‐min schedules of food reinforcement. Subjects were then tested for sensitivity to vestibular stimulation from rotation, using an ascending method of limits technique with increments in velocity of one revolution per minute every 5 min. Centrifugal forces were minimized by locating the test chamber over the axis of rotation. Response rates decreased in all subjects as a function of increasing rotation speed. In addition, characteristic differences in the patterns of response decrement were found between subjects on ratio and on interval schedules. Repeated tests indicated high intra‐subject reliability in sensitivity to rotation. Similarities of these data to “motion sickness” phenomena in other species were noted. It is suggested that this behavioral approach provides a sensitive and quantifiable technique for assessing the effects of vestibular stimulation in animals.
ATTACK PRODUCED BY INTERMITTENT REINFORCEMENT OF A CONCURRENT OPERANT RESPONSE1
Authors: Hutchinson R. R. , Azrin N. H. , Hunt G. M.
Published: March 2006

Squirrel monkeys pressed a lever to produce food on several fixed‐ratio schedules; they could also bite a rubber hose. Biting attack occurred during the postreinforcement pause and in early portions of the ratio response run. Also, biting attacks increased after transitions to higher values of the fixed‐ratio requirement and in extinction. The results show that extinction‐induced aggression effects occur in primates.
SUPPRESSION OF BEHAVIOR BY TIMEOUT PUNISHMENT WHEN SUPPRESSION RESULTS IN LOSS OF POSITIVE REINFORCEMENT1
Authors: Kaufman Arnold , Baron Alan
Published: March 2006

This investigation, using rats as subjects and punishment by timeout for responses maintained on a ratio schedule, sought to determine whether behavior would be suppressed by timeout punishment when such suppression also reduced reinforcement density or frequency. A series of experiments indicated that timeout punishment suppressed responding, with the degree of suppression increasing as a function of the duration of the timeout period. Suppressive effects were found to decrease as a function of increases in deprivation (body weight) and were eliminated when the punished response also was reinforced. It was concluded that timeout can produce aversive effects even when loss of reinforcement results. An alternative interpretation of the findings, based on the effects of extinction periods and delay of reinforcement on chained behavior, was discussed.
THE DISSOCIATION OF DISCRIMINATIVE AND CONDITIONED REINFORCING FUNCTIONS OF STIMULI WITH CHANGES IN DEPRIVATION1
Authors: Fischer Kurt , Fantino Edmund
Published: March 2006

Pigeons were studied in two experiments designed to explore the effects of deprivation level upon responding in each link of a two‐link chained schedule. The stimulus associated with the terminal link of the chain can be both a discriminative stimulus (SD) for responding in the presence of the stimulus and a conditioned reinforcer (Sr) for responding in the preceding link. Previous findings have indicated that the Sr function was more readily weakened by satiation than was the SD function, i.e., the rate of responding decreased more rapidly in the initial link of the chain than in the terminal link. The first of the present experiments, in which tests were conducted after a series of sessions, produced different results: rates of responding in the two links declined simultaneously. The second experiment supported the hypothesis that the effects of satiation interact with the duration of maintenance on the satiation procedure: in early sessions the Sr function was more readily disrupted, but in later sessions the rates of responding in the two links declined simultaneously. Subsequent to this extensive series of identical sessions, the pigeons' deprivation level was altered before a session by pre‐feeding the pigeons up to their normal post‐session weights. The rates of responding failed to reflect fully this change in deprivation in the first such session, suggesting that the pigeons' behavior had become partially independent of deprivation level.
STIMULUS BIAS IN THE ABSENCE OF FOOD REINFORCEMENT
Authors: Lander D. G.
Published: March 2006

Pigeons sometimes peck a key at different rates in the presence of different stimuli, even when the same schedule of reinforcement is correlated with each of these stimuli. The possibility that the occurrence of such stimulus bias is dependent on adventitious effects of food reinforcement in the presence of the stimuli was evaluated by correlating extinction with two stimuli. Both pigeons showed stimulus bias, indicating that the occurrence of this phenomenon is not critically dependent upon any effects of scheduled food reinforcements.
INDIFFERENCE BETWEEN PUNISHMENT AND FREE SHOCK: EVIDENCE FOR THE NEGATIVE LAW OF EFFECT1
Authors: Schuster Richard , Rachlin Howard
Published: March 2006

Pigeons were trained to respond under two conditions with two identical variable‐interval schedules of positive reinforcement. While the schedules operated for separate response keys, they were not available concurrently. During one condition, each response was punished with electric shock. During the other condition, shocks were delivered independently of responding. The punishment suppressed responding but the free shocks did not. However, when allowed to choose, the pigeons preferred the condition associated with the lowest rate of shock regardless of whether or not the shock was dependent on responding. In general, shocks exerted their greatest effect on whichever response had the greatest influence on shocks. In this respect, punishment is instrumental in suppressing behavior and the properties of punishment are symmetrical to those of reinforcement. This empirical symmetry dictates a corresponding conceptual symmetry in terms of a positive law of effect accounting for response increments and a negative law accounting for response decrements.
OPERANT CONTROL OF RESPONSE LATENCY IN MONKEYS: EVIDENCE FOR A CENTRAL EXPLANATION1
Authors: Saslow Carol A.
Published: March 2006

Two monkeys (M. mulatto) were trained to press a telegraph key after onset of a tone and release it quickly in response to a subsequent light or click stimulus occurring after a variable interval. After training first with a fixed time limit on response latency for key release and then with a continuously adjusting limit, reaction time to click was 160 msec and to light, about 200 msec. Temporal contingencies or “payoff bands” were then introduced which reinforced only responses with latencies which fell between two limits 50 msec apart. Feedback was given as to whether each latency was too slow, within the band, or too fast. A trained monkey could precisely center its latency distribution on any 50 msec‐wide payoff band located from 200 to 600 msec after the stimulus, with from 60 to 80% of its responses achieving reinforcement. Distribution statistics were comparable to those of trained human subjects. Because such precise timing might be accomplished by a peripheral adjustment, such as changing the manner of holding the key, latency of electromyographic activation was measured in participating arm muscles in one monkey. Electromyographic activation preceded key release by a constant interval, regardless of response latency, indicating a more central mechanism for timing of brief intervals.
FACTORS INFLUENCING INHIBITORY STIMULUS CONTROL: DISCRIMINATION TRAINING AND PRIOR NON‐DIFFERENTIAL REINFORCEMENT1
Authors: Weisman R. G. , Palmer Judith A.
Published: March 2006

In Exp. I, shallow U‐shaped gradients of inhibition in the line‐orientation dimension were obtained from birds that had a vertical (0°) line on a green surround correlated with extinction and a blank green surround correlated with reinforcement. Birds that had massed extinction in the presence of the 0° line showed flat gradients. Thus, discrimination training, but not massed extinction, appears to generate inhibitory control. In Exp. II, as in studies of control by a stimulus correlated with punishment, non‐differential training across the line‐orientation dimension preceded further sessions. Steep inverted gradients about the 0° line were obtained after discrimination training with the 0° line correlated with extinction. Gradients obtained after massed extinction tended to be flat. Again, discrimination training was critical in obtaining negative gradients of stimulus control.
THE EFFECT OF INFORMATIVE FEEDBACK ON TEMPORAL TRACKING IN THE PIGEON1
Authors: Staddon J. E. R.
Published: March 2006

Pigeons emitted interresponse times that were reinforced if they fell between an upper and a lower bound (t < IRT < t + t/10). Brief stimuli followed each response; under some experimental conditions the color of these stimuli was correlated with whether the preceding interresponse time was longer or shorter than that specified by the schedule. Preliminary experiments indicated that these “feedback” stimuli acquired no discriminative properties even after prolonged training. A modified procedure, in which t varied cyclically throughout each experimental session, allowed the stimuli to acquire such properties: stimulus control was demonstrated under the training conditions, for two of the pigeons, and under transfer conditions for all three birds. A series of probe conditions, followed by a replication of the simple procedure using a multiple schedule, indicated that the controlling property of the stimuli was not the relation between stimuli, interresponse time, and value of t, but a variable determined by the interaction between the animals' responding and the cyclic procedure. This variable was probably the relative frequency of the less‐frequent feedback stimulus.
REINFORCEMENT CONTINGENCIES MAINTAINING COLLATERAL RESPONDING UNDER A DRL SCHEDULE1
Authors: McMillan D. E.
Published: March 2006

Two‐key conjunctive schedules were studied with one key (food key) under a differential‐reinforcement‐of‐low‐rate 20‐sec schedule, while the consequences of responding on another key (collateral key) were varied. When food depended not only upon a food‐key interresponse time in excess of 20 sec, but also upon the occurrence of one or more collateral‐key responses during the food‐key interresponse time, the rate of collateral‐key responding was low and food‐key interresponse times rarely exceeded 20 sec. When collateral‐key responses could produce a discriminative stimulus correlated with the availability of food under the DRL schedule, the discriminative stimulus functioned as a conditioned reinforcer to maintain higher rates of collateral‐key responding, and the spacing of food‐key responses increased. If the occurrence of the discriminative stimulus was independent of collateral‐key responses, the rate of collateral‐key responding was again low, but the spacing of food‐key responses was still controlled by the discriminative stimulus. Both the conditioned reinforcer and the explicit reinforcement contingency could maintain collateral‐key responding, but the adventitious correlation between collateral‐key responses and the delivery of food could not maintain very much collateral‐key responding. The pattern of responding on the food‐key was determined to a much greater extent by the correlation between the discriminative stimulus and the delivery of food than by the pattern of responding on the collateral key.
REPEATED MEASUREMENTS OF REINFORCEMENT SCHEDULE EFFECTS ON GRADIENTS OF STIMULUS CONTROL1
Authors: Zeiler Michael D.
Published: March 2006

Two experiments studied the effects of reinforcement schedules on generalization gradients. In Exp. 1, after pigeons' responding to a vertical line was reinforced, the pigeons were tested with 10 lines differing in orientation. Reconditioning and the redetermination of generalization gradients were repeated from 8 to 11 times with the schedule of reinforcement varied in the reconditioning phase. Stable gradients could not be observed because the successive re‐conditionings and tests steepened the gradients and reduced responding. Experiment 2 overcame these effects by first training the birds to respond to all of the stimuli. Then, brief periods of reinforced responding to the stimulus correlated with reinforcement alternated with the presentation of the 10 lines in extinction. The development of stimulus control was studied eight times with each bird, twice with each of four schedules of reinforcement. Gradients were similar each time a schedule was imposed; the degree of control by the stimulus correlated with reinforcement varied with particular schedules. Behavioral contrast occurred when periods of reinforcement and extinction alternated and was more durable with fixed‐interval, variable‐interval, and variable‐ratio schedules than with fixed‐ratio or differential‐reinforcement‐of‐low‐rate schedules.
THE RABBIT AS A SUBJECT IN BEHAVIORAL RESEARCH1
Authors: Rubin H. B. , Brown H. J.
Published: March 2006

Domestic rabbits were exposed to a wide variety of variables employed in behavioral research. It was found that: (1) Although food could be used as a reinforcer, the long periods of severe deprivation required to reduce body weight made its use impractical. (2) Water was an efficient reinforcer in that it maintained high rates of behavior after 22 hr of deprivation. (3) Except that rates of responding were higher, fixed‐ratio and variable‐interval schedules of reinforcement produced patterns of behavior similar to those demonstrated by rats and pigeons. (4) Although the duration of the post‐reinforcement pause was a function of the duration of the interval under fixed‐interval schedules, scalloping, as defined as a gradually increasing rate of responding between reinforcement, was not evident. (5) When provided with the means to both turn on and turn off intracranial stimulation, the duration of the stimulation and the frequency with which it was turned on and off was a function of the intensity of the stimulation. (6) Electric shock could suppress behavior and maintain escape responding, but would maintain avoidance responding only in a few subjects.
REINFORCEMENT DURATION AND THE PEAK SHIFT IN POST‐DISCRIMINATION GRADIENTS1
Authors: Mariner Robert W. , Thomas David R.
Published: March 2006

Pigeons were trained to key‐peck for food, first with single‐stimulus training and then with successive discrimination (multiple schedule) training. In the multiple schedule, two different wavelengths were each correlated with equally frequent variable‐interval reinforcement but different durations (6 sec vs. 2 sec) of access to grain. For some birds, the different durations of feeding cycle were cued by different intensities of the food hopper light. For some of these “cued” birds, single‐stimulus training had been carried out with 6‐sec feedings and when multiple‐schedule training was introduced, the novel stimulus was correlated with 2‐sec feedings. For the others, 2‐sec feedings were originally used, and the novel stimulus was then present during the 6‐sec reinforcement duration. The cueing procedure enhanced discrimination performance, and was necessary for the consistent production of a peak shift. In addition, the condition in which original training had been carried out with 6‐sec feedings, and thus reinforcement duration was reduced in the presence of the novel stimulus, led to the best performance.
ANALYSIS OF RESPONSE RATES DURING STIMULUS GENERALIZATION1
Authors: Migler Bernard , Millenson J. R.
Published: March 2006

In the presence of one click frequency, the presses of two hungry rats on one of two levers were reinforced with food on variable‐interval schedules; in the presence of a different click frequency, presses on the other lever were reinforced. In stimulus generalization tests, a variety of click frequencies were presented and reinforcement withheld. The test stimuli were found to exert control over which of the two levers the rats pressed, but not over the rate of pressing the selected lever. The results were interpreted as further evidence that intermediate rates in generalization gradients may be the result of the alternation of several distinct behavior patterns.
THE CONTROL OF FEEDING BEHAVIOR BY AN IMPRINTED STIMULUS1
Authors: Hoffman Howard S. , Stratton James W. , Newby Valerie
Published: March 2006

Imprinted ducklings were trained to peck a pole using brief presentations of the imprinted stimulus as the response‐contingent (reinforcing) event. Subjects' were then permitted to spend extended periods with continuous access to food and the imprinted stimulus (via a pole peck). For other (control) subjects the experimental situation was restricted to either responding for the stimulus, or feeding in the absence of the stimulus. For subjects in the control conditions, both activities occurred in cyclic fashion. When, however, there was continuous opportunity to respond for the stimulus and food was available, the tendency to respond was related to the tendency to feed. Other experiments showed that independent presentations of the stimulus could initiate feeding in imprinted ducklings with no prior pairing of the stimulus with food and with no prior pole‐peck training. The most consistent control over feeding, however, was exhibited by ducklings that were imprinted and also accustomed to periodic removals of the stimulus. It is concluded that in ducklings, imprinting procedures are sufficient to endow an arbitrary stimulus with the capacity to release feeding behavior.
ATTENTION AND GENERALIZATION DURING A CONDITIONAL DISCRIMINATION1
Authors: Reynolds G. S. , Limpo A. J.
Published: March 2006

A conditional discrimination was established and analyzed, using four pigeons. The discrimination was among four compound stimuli projected on the response key—a white circle or triangle on a red or green background—during two conditions of illumination in the chamber, no illumination or flashing illumination. The two lighting conditions indicated whether the stimuli on the key containing triangles or those containing red would be the occasion for reinforcement. After the discrimination formed, generalization to intermediate and extreme values of the conditional stimulus and the attention of the birds to separate aspects of the stimulus on the key under each of the conditional stimuli were studied. All subjects generalized across values of the conditional stimulus, the lighting of the chamber. But subjects differed in the manner in which they treated the compound stimuli: two tended to attend to one or the other aspect of the stimulus on the key depending on the conditional stimulus, and two offered no evidence of such selective attention. Thus, the differential control of responding by the conditional stimuli cannot be attributed to a shift in attention between the figure and ground aspects of the compound stimuli.
EFFECTS OF d‐AMPHETAMINE ON OBSERVING BEHAVIOR IN THE SQUIRREL MONKEY1
Authors: Clark Fogle C.
Published: March 2006

Four squirrel monkeys were trained to press a lever, which produced stimuli indicating availability or non‐availability of reinforcement for pushing a key. Food reinforcements were available for the key response at random intervals with an average rate of 1 per min. When food was available, a single lever response produced a red light behind the key. Reinforcement availabilities and red keylights remained until terminated by a reinforced key response. When reinforcement was not available, each lever response produced a 0.5‐sec green light on the key. Except after lever responses, the key remained dark. Under this procedure, lever responses functioned as observing behavior in that they produced discriminative stimuli correlated with the availability or non‐availability of reinforcement for key responses. The procedure generated a high rate of responding on the lever, short latencies of the key response after onset of red lights and few responses to the key in the absence of red lights. Intramuscular d‐amphetamine, in doses from 0.125 to 1.0 mg/kg, abolished both observing behavior and key responding for periods that increased as a function of dose. However, both observing and key rates were increased at the smallest dose in two subjects whose performances included responding to the key in the absence of red lights. Results are discussed in relation to previous findings regarding effects of amphetamines on operant behavior and on observing and monitoring performance.
A NEW TECHNIQUE FOR MEASURING THERMOREGULATORY BEHAVIOR IN THE RAT
Authors: Wright John W. , Meyer Merle E.
Published: March 2006

A tracking procedure was used to investigate the ability of rats to regulate their ambient temperature. Rats were placed in a chamber with two levers; depressions of one lever controlled a cold‐water flow (11°C) and the other controlled the flow of hot water (57 ± 1°C). If it alternated responses, the rat could regulate temperature within these two extremes. With training, this regulatory behavior resulted in a narrow environmental temperature range that approximated normal body temperature.
THE CONCURRENT REINFORCEMENT OF TWO INTERRESPONSE TIMES: ABSOLUTE RATE OF REINFORCEMENT1
Authors: Shimp Charles P.
Published: March 2006

Three pigeons obtained food on a one‐key schedule of reinforcement for two concurrent, discriminated interresponse times. The overall rate of reinforcement was determined by a family of variable‐interval schedules and by a continuous reinforcement schedule. The average frequency of reinforcement varied from 1.1 to 300 reinforcements per hour; the relative frequency of reinforcement for each of the two interresponse times was 0.5 throughout the experiment. The number of responses per minute increased sharply as the number of reinforcements per hour increased from 1 to 20. Beyond 30 reinforcements per hour, the curve was approximately flat, although it sometimes decreased slightly at the highest reinforcement rates. The relative frequency of the shorter interresponse time also increased sharply as the number of reinforcements per hour increased from 1 to 20. The asymptote of the relative frequency function approximately equalled the relative reciprocal of the length of the shorter interresponse time for reinforcement rates greater than 30 or 40 reinforcements per hour. This approximation was obscured by the response‐rate function.
THE EFFECT OF A FADING PROCEDURE UPON THE ACQUISITION OF CONTROL BY AN OVERSHADOWED AUDITORY FEATURE1
Authors: Westbrook R. F. , Miles C. G.
Published: March 2006

Pigeons' key‐pecking responses were reinforced in the presence of a compound stimulus that consisted of an auditory feature (a tone) and a visual feature (a light) and non‐reinforced in the presence of a compound stimulus that was either a noise and a dark key, or noise and a light. In the condition where reinforcement trials differed from non‐reinforcement trials on the basis of both auditory and visual features, the tone exerted very little control over responding on test. In the condition where reinforcement differed from non‐reinforcement trials solely on the basis of the auditory features, an abrupt and a gradual introduction of the visual feature of the negative stimulus, a light, were compared for their effect upon control in the compounds. The tone acquired strong control in both cases. Evidence indicated that the tone had acquired control in the gradual condition without the occurrence of responses to the negative stimulus. An incidental finding was that when the negative stimulus consisted of a noise and a light, which was introduced abruptly, responding over the light dimension with tone, on test, was peaked at a point other than that light value used as positive and negative during training.