bluuebunny/crossref_metadata_2025 huggingface dataset:
POST‐REINFORCEMENT PAUSES AND RESPONSE RATE OF MONKEYS ON A TWO‐HAND FIXED‐RATIO SCHEDULE1
Authors: Laursen Arne Mosfeldt
Published: March 2006

Fixed‐ratio behavior of monkeys was analyzed separately for two hands. While one hand responded on the fixed‐ratio schedule the other performed a holding response and the function of the hands changed in alternate ratio runs. After performance was stable on the fixed ratio (70 responses, two monkeys; 100 responses, two monkeys, 120 responses, two monkeys) 90 sessions of further training equalized post‐reinforcement pauses and the mean interresponse time of the two hands. Hand preference in reaching for food remained unchanged. Then, the fixed‐ratio requirement was changed (a) in small sequential steps, (b) in two large steps, and, (c) within sessions alternating two runs at a high ratio with two runs at a low ratio. The mean duration of post‐reinforcement pauses was correlated with a fixed ratio maintained throughout a session but single pauses were neither controlled by the immediately preceding nor by the following ratio run when a cue to its length was available. The mean interresponse time was insensitive to changes in fixed ratio. The fixed‐ratio performance was generally similar to that of pigeons and rats.
FIXED‐RATIO PERFORMANCE UNDER CONDITIONS OF DELAYED REINFORCEMENT1
Authors: Morgan M. J.
Published: March 2006

Four rats were trained on a schedule in which completion of a fixed number of lever presses initiated a signalled delay period, at the end of which food was delivered. Lever presses made during the delay had no scheduled consequences. Delays of 12, 3, and 0.75 sec were used, and it was found that the latency of the first response after food (the post‐reinforcement pause) increased with length of delay. There was, on the other hand, no consistent effect of delay upon rates of responding after the post‐reinforcement pause.
AIRFLOW AS A DISCRIMINATIVE STIMULUS1
Authors: Van Houten Ronald , Seraganian Peter , Rudolph Robert
Published: March 2006

In one experiment, pigeons were taught to discriminate airflow by having availability of reinforcement signalled by its presence and extinction signalled by its absence. After they reached criterion, some were trained on a discrimination reversal. Others were trained on an intradimensional discrimination with a low airflow velocity associated with reinforcement and a higher airflow velocity associated with extinction. All discriminations were learned rapidly, indicating that airflow velocity can function as a discriminative stimulus. In the second and third experiments, naive pigeons were trained to discriminate the presence of a compound stimulus (one of three tonal intensities paired with one of three airflow velocities) from its absence. These pigeons were subsequently given a component stimulus test during extinction on four stimulus values; the two training values, the tone alone, and the airflow alone. High or moderate velocity airflow controlled more responding than any of the three tone intensities. However, low velocity airflow controlled more responding only when a low intensity tone was employed.
CONTROL OF PREFERENCE IN CHILDREN BY CONDITIONED POSITIVE REINFORCEMENT1
Authors: Favell Judith Elbert , Favell James E.
Published: March 2006

A preference measure was employed with children to evaluate the conditioned positive reinforcing function of a stimulus that preceded reinforcement. A match‐to‐sample procedure was arranged in which subjects could respond to either the form or color dimension of a compound sample stimulus. Intermittent token reinforcement was provided equally for color and form matches. Two stimuli were employed (Stimulus A and Stimulus B), each consisting of a distinctive tone and colored light. One of these stimuli (the paired stimulus) preceded each token delivery, and the other did not (nonpaired stimulus). The paired stimulus was dependent upon each response to one match dimension, and the nonpaired stimulus followed each response to the other dimension. Three of the five subjects responded primarily to the dimension that was followed by the paired stimulus. This effect was obtained regardless of which stimulus (A or B) was paired and on which match dimension (color or form) the paired stimulus was dependent. These results were unaltered by discontinuing the nonpaired stimulus. The other two subjects demonstrated consistent preferences for the form dimension and Stimulus A, respectively.
EFFECTS OF CONCURRENT SCHEDULES ON HUMAN FIXED‐INTERVAL PERFORMANCE1
Authors: Poppen Roger
Published: March 2006

Young adults performed a lever‐pressing task for money on two schedules of reinforcement: concurrent fixed‐interval 1 min—differential‐reinforcement‐of‐low‐rate 20‐sec, and concurrent fixed‐interval 1‐min—fixed ratio 100 responses. All subjects were trained on both schedules. Fixed‐interval performance concurrent with the differential reinforcement procedure was characterized by high constant rates with no post‐reinforcement pauses. Fixed‐interval performance concurrent with fixed ratio was characterized by low rates and lengthy post‐reinforcement pauses. These results differ from those obtained in prior studies on the effects of conditioning history upon subsequent fixed‐interval performance. The prior work, using non‐concurrent procedures, had shown that fixed‐interval performance following differential reinforcement of low rates was characterized by post‐reinforcement pauses and low rates, while fixed‐interval performance following fixed ratio exhibited high constant rates and no post‐reinforcement pause. The present results suggest that alternative concurrent contingencies are another major determinant of human fixed‐interval performance.
A YOKED‐CHAMBER COMPARISON OF CONCURRENT AND MULTIPLE SCHEDULES
Authors: Killeen Peter
Published: March 2006

Pigeons were exposed to alternative pairs of variable‐interval schedules correlated with red and green lights on one key (the food key). In one experimental chamber, responses on a white key (the changeover key) changed the color of the food key and initiated a 2‐sec changeover delay. Pigeons in a second chamber obtained food by pecking on a colored key whenever the pigeons in the first (concurrent) chamber had obtained food for a peck on that key color. There was no changeover key in the second (multiple) chamber: changeover responses in the first chamber alternated the schedules and colors in both chambers. The pigeons in both chambers emitted the same proportion of responses on each of the variable‐interval schedules, and mastered discrimination reversals at the same rate. The pigeons differed only in their absolute response rates, which were greater under the concurrent schedules. In a second experiment, changes in key color occurred automatically, with different proportions of time allocated to the two variable‐interval schedules. Matching of relative response frequency to relative reinforcement frequency was affected by the relative amounts of time in each component, by rate of changeovers, and by manipulations of the variable‐interval scheduling.
EFFECTS OF DIFFERENT DELAY OF REINFORCEMENT PROCEDURES ON VARIABLE‐INTERVAL RESPONDING1,2
Authors: Pierce C. H. , Hanford P. V. , Zimmerman J.
Published: March 2006

Two experiments studied responding in the rat when the first bar press after a variable period of time produced a cue light that remained on for either 10, 30, or 100 sec and terminated with the delivery of food. In Experiment I, response rate decreased and time to the first response after reinforcement increased as the delay of reinforcement increased. Similar results were obtained whether the delay consisted of retracting the lever during the delay, a fixed delay with no scheduled consequence for responding, or every response during the delay restarted the delay interval. In Experiment II, fixed‐delay and fixed‐interval schedules of the same duration during the delay period had no differential effect on either response rate or time to the first response after reinforcement, but differentially controlled responding during the delay periods.
IN COMPATABILITY BETWEEN THE PIGEONS' UNCONDITIONED RESPONSE TO SHOCK AND THE CONDITIONED KEY‐PECK RESPONSE1
Authors: Smith Richard F. , Gustavson Carl R. , Gregor Gary L.
Published: March 2006

High‐speed photography was used to compare the pigeon's response to unsignalled shock with the pigeon's key‐peck response. During shock, pigeons flex their neck (i.e., the distance between their eyes and shoulders decreases). Following shock, the neck is extended. During key pecking, the neck remains extended and the head moves toward the key in a slight arc as though attached to a fixed fulcrum. Response topography during pecking and shock appear to be incompatible, and it is concluded that the difficulty in key‐peck training pigeons to escape electric shock is due to interference from the unconditioned flexion response. This conclusion supports the species‐specific defense theory of escape and avoidance behavior.
VICARIOUS CONDITIONED ACCELERATION: SUCCESSFUL OBSERVATIONAL LEARNING OF AN AVERSIVE PAVLOVIAN STIMULUS CONTINGENCY
Authors: Riess Dave
Published: March 2006

Five rats (observers) were trained to avoid unsignalled shocks in a shuttlebox and then habituated to brief light presentations. They were next confined on an observation platform while another rat (model) received light‐shock pairings in the opposite compartment. The observers were exposed only to the sight and sound of the model during classical conditioning and were not shocked themselves. Test presentations of the light during subsequent avoidance sessions produced response rate increases (vicarious conditioned acceleration) comparable to those obtained in other studies where the avoidance animals were used in classical conditioning. Following sessions in which the model was not shocked after the light, the light presentations during avoidance eventually failed to elicit any response increases in the observers. When the model was again shocked, immediate recovery of avoidance acceleration occurred in the observers during the light.
RESPONDING UNDER DISCRETE‐TRIAL FIXED‐INTERVAL SCHEDULES OF REINFORCEMENT1
Authors: Schneider Bruce A. , Neuringer Allen J.
Published: March 2006

A fixed‐interval schedule of reinforcement was modified by dividing each interval into 4‐sec trial periods. No more than one response could occur during each trial because the operandum was inactivated for the remainder of any trial in which a response occurred. For example, under a 28‐sec schedule, no more than seven responses could be emitted between reinforcements. Probabilities of responding by pigeons under six values of this discrete‐trial fixed‐interval schedule were best described by a two‐state model: responding was either absent or infrequent immediately after reinforcement; then, at some variable time after reinforcement, there was an abrupt transition to a high and constant probability of responding on each trial. Performances under the discrete‐trial procedure were less affected by uncontrolled sources of variance than performances under equivalent free‐operant fixed‐interval schedules.
TWO DIFFERENT KINDS OF KEY PECK IN THE PIGEON: SOME PROPERTIES OF RESPONSES MAINTAINED BY NEGATIVE AND POSITIVE RESPONSE‐REINFORCER CONTINGENCIES1
Authors: Schwartz Barry , Williams David R.
Published: March 2006

Pigeons emitted almost exclusively short‐duration key pecks (shorter than 20 msec) when on negative automaintenance procedures, in which pecks prevented reinforcement. Peck durations under fixed‐interval and fixed‐ratio reinforcement schedules were generally two to five times longer than pecks under a negative automaintenance schedule. However, initial key pecks were of short duration, independent of procedure. The frequency of short‐duration pecks was insensitive to differential reinforcement, while the frequency of long‐duration pecks was sensitive to differential reinforcement. It is proposed that short‐duration pecks arise from the pigeon's normal feeding pattern and are directly enhanced by food presentation, while long‐duration pecks are controlled by the contingent effects of food presentation. The implications of the existence of two classes of pecks for the functional definition of operants and the separation of phylogenetic and ontogenetic sources of control of key pecking are discussed.
THE DEVELOPMENT OF STIMULUS CONTROL WITH AND WITHOUT A LIGHTED KEY1
Authors: Van Houten Ronald , Rudolph Robert
Published: March 2006

In two experiments, the effect of an illuminated response key on the acquisition of stimulus control by an airflow stimulus was assessed. In the first experiment, pigeons were given nondifferential training with airflow emerging from behind the response key in one of three conditions of illumination: trained to peck a lighted key, trained to peck an unlighted key with a houselight present, trained to peck a key in total darkness. After 10 days of training on a variable‐interval schedule of reinforcement, all subjects were given a generalization test on airflow velocity. The gradients for subjects trained in the dark were sharp, while those for subjects trained in lighted conditions were shallow. In the second experiment, the effect of an irrelevant keylight on the acquisition of an airflow velocity discrimination was assessed. Two groups of pigeons were trained to discriminate two airflow velocities. One group was trained with a lighted response key and the other was trained to peck the response key in total darkness. The dark‐trained subjects acquired the discrimination more rapidly. The results demonstrate that the acquisition of stimulus control by airflow with either a differential or nondifferential training procedure can be overshadowed by keylight.
REINFORCEMENT OMISSION ON TEMPORAL GO—NO‐GO SCHEDULES1
Authors: Staddon J. E. R.
Published: March 2006

Either a partial blackout, or the blackout plus a “feeder flash”, occurred in lieu of reinforcement on two procedures that produced opposite patterns of responding after reinforcement. Response rate was elevated after reinforcement omission on the procedure that produced a “pause‐and‐respond” pattern following reinforcement, but depressed after reinforcement omission on the procedure that produced a “respond‐and‐pause” pattern. The effect of blackout plus feeder flash was generally intermediate between the effects of blackout and the effects of reinforcement. These results are consistent with an interpretation of reinforcement omission effects in terms of the discriminative temporal control exerted by reinforcement and stimuli similar to it.
THE PSYCHOLOGICAL DISTANCE TO REWARD1
Authors: Duncan Barbara , Fantino Edmund
Published: March 2006

Pigeons' responses in the presence of two concurrently available (initial‐link) stimuli produced entry into one of two different and mutually exclusive terminal link stimuli according to identical but independent variable‐interval schedules. In one experiment, a two‐component chained fixed‐interval schedule produced food in one terminal link while a simple fixed‐interval schedule produced food in the other terminal link. When the interreinforcement intervals were equal in the two terminal links (i.e., the simple fixed‐interval was twice the size of each of the components in the chained schedule) pigeons preferred the simple fixed‐interval as measured by their relative rates of responding in the concurrently available initial links. This preference increased as the duration of the terminal links increased. The preference could be reversed by making the simple fixed‐interval schedule sufficiently longer than the chained schedule. In the second experiment, the terminal links consisted of two‐ vs three‐component chained fixed‐intervals, again with equal interreinforcement intervals. Pigeons preferred the two‐component chain to the three‐component chain, although these results were less consistent and less dramatic than those in the first experiment. Again, preference increased as the duration of the terminal links increased. The results show that an organism's choice for a schedule will be substantially lowered by the chaining operation even when the interreinforcement interval remains constant.
THE EFFECTS OF TERMINAL‐LINK FIXED‐INTERVAL AND VARIABLE‐INTERVAL SCHEDULES ON RESPONDING UNDER CONCURRENT CHAINED SCHEDULES1
Authors: MacEwen David
Published: March 2006

Previous work using variable‐interval schedules in the terminal links of concurrent chained schedules suggested that relative choice proportion in the initial links equalled relative rate of reinforcement in the terminal links. With fixed‐interval terminal‐link schedules, however, matching was not obtained. The present study held pairs of fixed‐interval terminal‐link schedules in a constant ratio but varied absolute sizes. Relative choice for the smaller terminal‐link fixed‐interval schedule was a negatively accelerated, increasing function of absolute size of the fixed‐interval pairs. Matching was found only with the fixed‐interval pair of 5 and 10 sec. When pairs of variable‐interval schedules were arranged so that the harmonic mean of the intervals equalled the fixed‐interval parameter values, relative choice functions were like those for fixed‐interval schedules.
THE WYCKOFF OBSERVING RESPONSE—A REAPPRAISAL1
Authors: Hirota Theodore T.
Published: March 2006

Pigeons were trained on a Wyckoff observing response procedure in which key responses were reinforced on a mixed schedule consisting of fixed‐interval and extinction components. In Experiment 1, stepping on a pedal (a) converted the mixed schedule to a multiple schedule, (b) replaced the mixed‐schedule stimulus with an unlit key (or, in different phases, a blackout), or (c) had no consequence. In Experiment 2, pedal standing removed the mixed‐schedule stimulus that was physically similar to the multiple‐schedule stimuli or one that was less similar. In Experiment 3, Wyckoff's differential and nondifferential discrimination procedure was repeated. The results of Experiments 1 and 2 showed that the Wyckoff pedal response was controlled by neither the removal of the mixed‐schedule stimulus nor the production of discriminative stimuli. The results indicated a correlation between key‐response rates and pedal‐standing time. Experiment 3 showed that high response rates to mixed‐schedule stimuli were correlated with little pedal‐standing time while high key‐response rates to multiple‐schedule stimuli were correlated with considerable pedal standing time. The correlation between key‐response rates and pedal‐standing time was related to the physical arrangement between the key and pedal operanda.
CONCURRENT PERFORMANCES: A BASELINE FOR THE STUDY OF CONDITIONED ANXIETY1
Authors: de Villiers Peter A. , Millenson J. R.
Published: March 2006

Three rats were trained to lever press on concurrent random interval 2‐min random interval 2‐min schedules of milk reinforcement. With a 5‐sec changeover delay, relative response rate matched the relative reinforcement duration associated with each lever. A stimulus, during which unavoidable shocks occurred at random intervals, was superimposed on this concurrent baseline, and shifts in preference were found. However, data from this procedure were ambiguous, apparently confounded by shock‐elicited response bursts. Termination of the shocks during the stimulus resulted in a rapid recovery of matching, which was preceded by a brief facilitation of responding on the less‐preferred lever. The procedure was then changed to a conventional conditioned anxiety paradigm with a variable duration pre‐shock stimulus. A marked shift in relative response rate towards the preferred lever was found in all three rats; that is, responding on the preferred lever was far less suppressed during the pre‐shock stimulus than responding on the less‐preferred lever.
EFFECTS OF RESPONSE‐SHOCK INTERVAL AND SHOCK INTENSITY ON FREE‐OPERANT AVOIDANCE RESPONDING IN THE PIGEON1
Authors: Klein Marty , Rilling Mark
Published: March 2006

Two experiments investigated free‐operant avoidance responding with pigeons using a treadle‐pressing response. In Experiment I, pigeons were initially trained on a free‐operant avoidance schedule with a response‐shock interval of 32 sec and a shock‐shock interval of 10 sec, and were subsequently exposed to 10 values of the response‐shock parameter ranging from 2.5 to 150 sec. The functions relating response rate to response‐shock interval were similar to the ones reported by Sidman in his 1953 studies employing rats, and were independent of the order of presentation of the response‐shock values. Shock rates decreased as response‐shock duration increased. In Experiment II, a free‐operant avoidance schedule with a response‐shock interval of 20 sec and a shock‐shock interval of 5 sec was used, and shock intensities were varied over five values ranging from 2 to 32 mA. Response rates increased markedly as shock intensity increased from 2 to 8 mA, but rates changed little with further increases in shock intensity. Shock rates decreased as intensity increased from 2 to 8 mA, and showed little change as intensity increased from 8 to 32 mA.
SCHEDULES OF ELECTRIC SHOCK PRESENTATION IN THE BEHAVIORAL CONTROL OF IMPRINTED DUCKLINGS1
Authors: Barrett James E.
Published: March 2006

The behavioral effects of various schedules of electric shock presentation were investigated during and after the imprinting of Peking ducklings to moving stimuli. The behavior of following a moving imprinted stimulus was differentially controlled by a multiple schedule of punishment and avoidance that respectively suppressed and maintained following behavior. Pole‐pecking, reinforced by presentations of the imprinted stimulus, was suppressed by response‐produced shock (punishment); various schedules of response‐independent shock and delayed punishment had an overall minimal effect. The delivery of response‐independent shock in the presence of one of two stimuli, both during and after imprinting, resulted in a marked reduction in choice of the stimulus paired with shock. The experiments provide no support for a differentiation of imprinting from learning on the basis of the behavioral effects of aversive stimuli. Instead, as is the case with other organisms, the schedule under which shock is delivered to imprinted ducklings appears to be an important determinant of the temporal patterning of subsequent behavior.
CHOICE BEHAVIOR AND THE ACCESSIBILITY OF THE REINFORCER1
Authors: Fantino Edmund , Squires Nancy , Delbrück Nicola , Peterson Christa
Published: March 2006

In Experiment 1, matching of relative response rates to relative rates of reinforcement was obtained in concurrent variable‐interval schedules when the absolute values of the two concurrent variable‐interval schedules varied from 6 sec and 12 sec to 600 sec and 1200 sec. Increases in the duration of the changeover delay, however, produced decreases in the relative response rates and, consequently, some deviation from matching. In Experiment 2, matching of relative response rates to the relative duration of the reinforcer failed to occur when the equal variable‐interval schedules arranging access to the two different reinforcer durations (1.5 and 6 sec) were varied in size from concurrent variable‐interval 10‐sec schedules to concurrent variable‐interval 600‐sec schedules.
SECOND‐ORDER SCHEDULES: COMPARISON OF DIFFERENT PROCEDURES FOR SCHEDULING PAIRED AND NONPAIRED BRIEF STIMUL1
Authors: Stubbs D. Alan , Cohen Steven L.
Published: March 2006

Pigeons performed on a second‐order schedule in which fixed‐interval components were maintained under a variable‐interval schedule. Completion of each fixed‐interval component resulted in a brief‐stimulus presentation and/or food. The relation of the brief stimulus and food was varied across conditions. Under some conditions, the brief stimulus was never paired with food. Under other conditions, the brief stimulus was paired with food; three different pairing procedures were used: (a) a response produced the simultaneous onset of the stimulus and food; (b) a response produced the stimulus before food with the stimulus remaining on during food presentation; (c) a response produced the stimulus and the offset of the stimulus was simultaneous with the onset of the food cycle. The various pairing and nonpairing operations all produced similar effects on performance. Under all conditions, response rates were positively accelerated within fixed‐interval components. Total response rates and Index of Curvature measures were similar across conditions. In one condition, a blackout was paired with food; with this different stimulus in effect, less curvature resulted. The results suggest that pairing of a stimulus is not a necessary condition for within‐component patterning under some second‐order schedules.
REINFORCEMENT OF SPACED RESPONDING IN A SIMULTANEOUS DISCRIMINATION1
Authors: Zeiler Michael D.
Published: March 2006

Pigeons were exposed to three stimuli simultaneously with responses reinforced according to differential‐reinforcement‐of‐low‐rate schedules. Responses to one stimulus (the positive stimulus) that were spaced appropriately resulted in food presentation. The variables manipulated were the time parameter of the schedule (5, 10, 20, 30 sec) and the consequences of responding to the other two stimuli (the negative stimuli). The percentage of the total responses that occurred to each stimulus was independent of the schedule value but was dependent on the consequences of responding to the negative stimuli. If responses to both reset the schedule timer, responding was confined largely to the positive stimulus. If responses to neither had scheduled effects, the birds were more likely to respond to those stimuli. Responding to one negative stimulus could be selectively attenuated by having responses to that stimulus alone reset the timer. With the schedule time value held constant, the absolute rate of responding to the positive stimulus was either stable or decreased with maintained exposure; it did not change as a function of increases or decreases in responding to the negative stimuli. Rather than interacting and affecting each other, responses to the three stimuli were controlled independently by their relation to reinforcement. There was no evidence that responses to the negative stimuli mediated the spacing of responses to the positive stimulus.
CHOICE BETWEEN TWO‐COMPONENT CHAINED AND TANDEM SCHEDULES1
Authors: Schneider J. W.
Published: March 2006

Pigeons were trained on a two‐key choice procedure in which a pair of equal and concurrently available variable‐interval schedules (initial links) arranged entry into one or the other of two mutually exclusive schedules (terminal links) that ended in primary reinforcement. The terminal links were two‐component chained or tandem schedules. Responses during the initial links were distributed equally on the two keys whenever the terminal links were associated with the same sets of interreinforcement intervals. Whether or not the terminal‐link interreinforcement intervals were the same on the two keys, initial‐link responding was affected by neither the presence nor relative durations of differentially signalled components within a terminal‐link schedule. The simplest interpretation of these results is that initial‐link responding is maintained directly by delayed primary reinforcement, rather than conditioned reinforcement afforded by the stimuli correlated with the terminal‐link schedule components. This finding suggests that aspects of chained schedule performance usually attributed to conditioned reinforcement might best be reinterpreted in terms of delayed primary reinforcement and various discriminative functions served by the component‐correlated stimuli.
CONTROL OF RESPONDING BY LOCATION OF AUDITORY STIMULI: ROLE OF DIFFERENTIAL AND NON‐DIFFERENTIAL REINFORCEMENT1
Authors: Downey Paul , Harrison J. M.
Published: March 2006

Sound was presented to monkeys through one of two loudspeakers, each adjacent to a response key. A response on the key adjacent to the sound source was reinforced (correct response). A response on the other key produced a timeout (incorrect response). Under these conditions, over 90% of responses were correct within one or two sessions. When the procedure was changed so that a response on either key was reinforced independently of which speaker was sounding, similar control by location developed within one or two sessions. When conditions were modified by moving the keys away from the immediate vicinity of the speakers, the animals required about 20 sessions to reach a stable level of greater than 90% correct responses under differential reinforcement conditions. No control by location developed under nondifferential reinforcement conditions.
THE DETECTION OF VISUAL INTENSITY DIFFERENCES BY PIGEONS
Authors: Hodos William , Bonbright James C.
Published: March 2006

Pigeons were trained in a conditional discrimination procedure to discriminate between visual stimuli that varied in intensity. The magnitude of the intensity difference ranged from 0.80 to 0.05 logarithmic units. Psychometric functions were calculated from the data and the mean difference threshold for the 11 subjects was approximately 0.12 logarithmic units. A signal‐detection analysis of the data suggested that stimuli that were below the calculated threshold were detectible to the subjects.
REINFORCEMENT AND RESPONSE RATE INTERACTION IN MULTIPLE RANDOM‐INTERVAL AVOIDANCE SCHEDULES1
Authors: de Villiers Peter A.
Published: March 2006

Two experiments were conducted to investigate the interaction between response rate and reinforcement frequency in multiple random‐interval avoidance schedules. Responses cancelled delivery of shocks that could be scheduled at different random intervals in each component. When shock‐frequency reduction was taken as the measure of reinforcement, the relationship between response rate and frequency of reinforcement was described by the same equations used by Herrnstein (1970) to describe responding with positive reinforcement.
PUNISHMENT CONTRAST DURING FREE‐OPERANT AVOIDANCE
Authors: Lattal Kennon A. , Griffin Margaret A.
Published: March 2006

Punishment of bar‐pressing responses of rhesus monkeys with electric shock in one component of a multiple free‐operant avoidance schedule suppressed responding in that component. These decreases were concomitant with response rate increases in the unpunished component (punishment contrast). Response rates in both components increased when punishment was removed and decreased in successive sessions. These effects of punishment on unpunished responding were similar to those obtained during single and multiple schedules of positive reinforcement and they suggest a further similarity in the development of discriminations during positive and negative reinforcement schedules.
LEVER ATTACKING BY RATS DURING FREE‐OPERANT AVOIDANCE1
Authors: Pear Joseph J. , Moody Joseph E. , Persinger Michael A.
Published: March 2006

Rats pressed a lever to avoid shock on a free‐operant avoidance schedule. Some subjects were also exposed to extinction in which the response‐shock contingency was eliminated while the shock‐shock contingency remained in effect. A specially constructed lever was used that registered not only presses, but also biting attacks on the lever. Throughout various phases of the study, shocks often elicited lever biting as well as post‐shock responding. The results suggested that shock‐elicited attacks that are forceful enough to activate the operandum might account for some of the responding that occurs in experiments on free‐operant avoidance behavior. In particular, shock‐elicited operandum attacking might account for post‐shock response bursting during free‐operant avoidance and the extreme persistence of responding sometimes noted when shocks are delivered during the extinction of avoidance behavior. To the extent that this is true, these phenomena should not be characterized as operant behavior in interpreting the results of experiments on free operant avoidance.
ACCURACY OF PERFORMANCE ON A MATCHING‐TO‐SAMPLE PROCEDURE UNDER INTERVAL SCHEDULES1
Authors: Boren M. C. P. , Gollub L. R.
Published: March 2006

Correct matches on a matching‐to‐sample procedure were reinforced under fixed‐interval, chained fixed‐interval, and fixed‐interval schedules with exteroceptive stimulus changes correlated with time since the last reinforcer (an added clock). For all four pigeons, accuracy changed within the fixed‐interval and fixed‐interval schedules with added clock, decreasing from the beginning of the interval to some point in the middle. The performance then became increasingly more accurate until the end of the interval. Under the chained schedules, accuracy also changed within the components. During the initial component, accuracy decreased from the beginning of the fixed interval to some point in the middle or at the end. During the middle component, the performance usually remained at an intermediate level of accuracy. During the terminal component, the initially inaccurate performance became increasingly more accurate throughout the interval. Systematic relationships between response rate and per cent error showed that all four pigeons performed most accurately at high rates. The accuracy of the performance at low rates was also quite high. These relationships held for all three types of schedules through an eight‐fold variation in scheduled interreinforcement time.
BEHAVIORAL DEFINITION OF MINIMAL REACTION TIME IN MONKEYS1
Authors: Saslow Carol A.
Published: March 2006

Two monkeys (Macaca mulatta) were trained to press a key after onset of a tone and to release it after a 1‐sec fixed foreperiod terminated by a light. The effects of imposing temporal contingencies on key release reaction times were determined by reinforcing only those releases whose latencies from the light fell within a “payoff band”, two time limits 50 msec apart located at some delay following the light. Over several days this delay was first gradually decreased, shortening the interval between light and payoff band, and then gradually increased again. For each delay, the median reaction time and a measure of variability were obtained from the latency distribution. For both animals, median latency could be decreased to 180 msec with the variability remaining small. Moving the payoff band still closer to the light resulted in further decrease in median latency but an abrupt increase in variability. This is in agreement with a model for simple reaction time derived from human research which suggests that this increased variability results from the inclusion of high‐variability foreperiod time estimations in the latency distribution. These results indicate that interpretation of monkey response latencies as “minimal reaction times” requires examination of temporal reinforcement contingencies and variability of latencies.
DRUGS AND PUNISHED RESPONDING I: RATE‐DEPENDENT EFFECTS UNDER MULTIPLE SCHEDULES1
Authors: McMillan D. E.
Published: March 2006

The effects of drugs were studied in pigeons whose responses were punished with electric shock during one component of a multiple fixed‐interval 5‐min fixed‐interval 5‐min schedule of food presentation. Most of the drugs analyzed for rate‐dependent effects increased low rates of both punished and unpunished responding, while increasing higher rates less, or decreasing them; however, low rates of punished responding sometimes were increased more by pentobarbital, diazepam, and chlordiazepoxide than were matched rates of unpunished responding. In contrast, d‐amphetamine and chlorpromazine usually increased low rates of unpunished responding more than matched rates of punished responding. These two drugs also decreased high rates of unpunished responding less than they decreased high rates of punished responding. Thus, the effects of drugs on punished responding depend on the control rate of punished responding; however, the rate‐dependent effects of drugs on punished responding are not always the same as they are for unpunished responding.
PERFORMANCE IN CONCURRENT FIXED‐INTERVAL SCHEDULES1
Authors: White A. J. , Davison M. C.
Published: March 2006

Six pigeons were trained on a variety of concurrent fixed‐interval fixed‐interval schedules. Matching between response or time ratios and ratios of obtained numbers of reinforcements was found for eight of 12 schedules studied. Cumulative records showed both typical burst‐and‐break patterns and also atypical response patterns in which response rate was constant between reinforcements on a schedule. Matching occurred only when the same pattern was present on both concurrent schedules. When different response patterns were generated by the two schedules, the pigeons consistently emitted fewer responses to the shorter fixed‐interval than required by matching.
EFFECTS OF FOOD DEPRIVATION ON FREE‐OPERANT AVOIDANCE BEHAVIOR1
Authors: Leander J. David
Published: March 2006

Lever pressing was maintained by Sidman's shock‐postponement procedure and Herrnstein and Hineline's shock‐frequency‐reduction procedure with rats. Food deprivation to 80% and 70% of the animals' body weights on free feeding resulted in decreased response rates in both avoidance paradigms tested. Reinstatement of free‐feeding conditions increased body weights and response rates and decreased shock rates. The effects of food deprivation were not dependent upon any particular avoidance parameters, or types, intensities, or durations of electric shock. These results mean that weight control is essential in long‐term studies of avoidance behavior, and in studies of the effects on avoidance behavior of physiological interventions, such as hypothalamic lesions, that themselves may produce weight changes.
FUNCTION OF INTERTRIAL INTERVAL IN MATCHING‐TO‐SAMPLE1
Authors: Holt Gary L. , Shafer James N.
Published: March 2006

Twelve pigeons were trained on matching‐to‐sample using either a 0‐, 5‐, 15‐, 25‐, or 60‐sec intertrial interval. Eight of these 12 pigeons were given one of the following intertrial interval changes: 0 to 60, 0 to 5, 5 to 0, 60 to 0, 15 to 25, 5 to 15, 60 to 5, 5 to 1, 1 to 5, 1 to 25, and 25 to 1 sec. Most intertrial interval changes were repeated at least once. The 0‐sec intertrial interval subjects failed to match beyond chance levels, while other intertrial interval values resulted in matching acquisition. Changes from 0 sec to other intertrial interval values increased and changes to 0 sec decreased matching performance. Changes to intertrial interval values other than 0 sec resulted in little change in matching accuracy once stable performance had been attained.
MAINTAINING RESPONDING DURING STIMULUS GENERALIZATION TESTING IN EXTINCTION1
Authors: Malott Kay , Malott Richard W. , Glenn Michael F.
Published: March 2006

Resistance to extinction and generalization gradients were studied following training with a long‐adjusting‐interval schedule. One large reinforcer occurred at the end of each daily training session. Sessions varied in length from 20 sec to 42.66 min, but were usually the latter. Repeated generalization tests were subsequently conducted for these subjects and subjects trained with a more conventional short‐random‐interval schedule. The long‐adjusting‐interval schedule produced generalization gradients that were not qualitatively different from those produced by the conventional procedure. However, the advantages of the long‐adjusting‐interval schedule are: (1) greater resistance to extinction both within and across generalization tests and (2) more stable gradient slopes within and across tests.
CHOICE OF LONGER OR STRONGER SIGNALLED SHOCK OVER SHORTER OR WEAKER UNSIGNALLED SHOCK1
Authors: Badia Pietro , Culbertson Stuart , Harsh John
Published: March 2006

Unsignalled, inescapable shocks were presented to four albino rats in one study and to six rats in a second study. By pressing a lever, subjects could change the condition to signalled shock for 3 min after which unsignalled shock was automatically reinstated. All subjects changed frequently to the signalled shock schedule. After a minimum of three 6‐hr sessions or after changeover responding stabilized at the previous values, higher values of signalled shock intensity or duration were introduced. In the first study, the duration of signalled shock was increased in increments of 0.5 sec. In the second study, the intensity of signalled shock was increased in increments of either 0.2 or 0.4 mA. Duration subjects chose signalled shock four (2.0 sec) to nine times (4.5 sec) longer than unsignalled shock (0.5 sec). Intensity subjects chose signalled shock two (2.0 mA) to three times (3.0 mA) more intense than unsignalled shock (1.0 mA).
SELF‐IMPOSED TIMEOUTS UNDER INCREASING RESPONSE REQUIREMENTS1
Authors: Dardano J. F.
Published: March 2006

Self‐imposed timeouts by pigeons working under a progressive‐ratio food schedule were studied under different conditions. The main findings were (1) continued production of timeouts over an extended series of sessions, (2) more frequent responding on the key with the timeout consequence than on a key having no consequence, (3) an inverse relationship between number of timeouts and level of body weight, (4) production of timeouts when the timeout duration was brief, lengthy, or controlled by the pigeon, and (5) dependence of self‐imposed timeouts on variables controlling responding under the progressive‐ratio schedule. Under all experimental conditions, with the exception of performances at the high body weight, timeouts were more frequent during the longer progressive‐ratio steps and usually were localized in the post‐reinforcement pause or the early part of the step. The timeout behavior could be interpreted as either an escape from aversive stimuli generated by the progressive‐ratio schedule or as a response reinforced by the consequent stimulus change.
RESPONSE DECREMENTS PRODUCED BY EXTINCTION AND BY RESPONSE‐INDEPENDENT REINFORCEMENT1
Authors: Boakes Robert A.
Published: March 2006

The effects of extinction and of response‐independent (free) reinforcement in decreasing rates of key pecking by pigeons were compared in single schedule (Phase 1) and multiple (Phase 2) conditions. In both phases, response rates decreased more rapidly with extinction than with free reinforcement conditions. Behavioral contrast was obtained from subjects trained in a multiple schedule involving extinction in Phase 2, whereas subjects trained in a multiple schedule involving free reinforcement showed a slight negative induction effect. Whether subjects experienced extinction or free reinforcement under single stimulus conditions did not affect subsequent performance in the discrimination situation of the second phase. Disinhibition testing was carried out at the end of both phases, but there was no evidence for disinhibitory effects under any condition.
ANALYSIS OF THE CONTROL EXERTED BY A COMPLEX COOPERATION PROCEDURE1
Authors: Hake D. F. , Vukelich Ron
Published: March 2006

The study examined the effects of the availability of a non‐cooperative response on cooperative responding when cooperation did not have to result in an equal distribution of work or reinforcers. Also, an attempt was made to determine if the cooperative responding was under the control of the cooperation procedure. Pairs of institutionalized retardates were tested in full view of each other. For each subject, reinforcers (money) were contingent upon responses on each of two panels: (1) a matching panel for working matching‐to‐sample problems, and (2) a sample panel for producing the sample stimulus. The matching panels of the two subjects were 6 m apart, but a subject's sample panel could be placed at different distances from his matching panel. For each subject, either his own or his partner's sample panel could be nearest his matching panel such that less walking was required to reach one sample panel than the other. Subjects could work either individually, by producing their own sample stimulus, or cooperatively, by producing the sample stimulus for their partner. Subjects selected whichever solution involved the least amount of walking. The importance of testing for control by the cooperation procedure was indicated by the findings that cooperative‐like responses were not always under the control of the cooperation procedure.
STIMULUS GENERALIZATION AND DELAY OF REINFORCEMENT DURING ONE COMPONENT OF A MULTIPLE SCHEDULE1
Authors: Richards Ralph W.
Published: March 2006

The key pecking of six pigeons was reinforced according to a variable‐interval 1‐min schedule during each of two successively presented stimuli. When the key was illuminated by a black line on a white background, reinforcement was delayed for 10 sec. When the key was illuminated by a plain white light, reinforcement was not delayed. All subjects responded at a lower rate during the presentation of the black line. A subsequent generalization test along the line‐orientation dimension produced a U‐shaped gradient, with the nadir located at or near the training stimulus, for each subject. These gradients suggested that the lower rate of response during the stimulus associated with delayed reinforcement may have been due to an inhibition of responding.
A RATE MEASURE OF THE RELATIVE AVERSIVENESS OF SIGNALLED VS UNSIGNALLED SHOCK1
Authors: MacDonald Larry , Baron Alan
Published: March 2006

Five rats were trained on a two‐component multiple schedule with each component consisting of a two‐link chain schedule. Differential response suppression in the initial links of the chain schedules was used as a measure of the relative aversiveness of events introduced into the subsequent terminal links. When unsignalled shock was scheduled in one terminal link and signalled shock in the other (in addition to equal numbers of food reinforcers), responding was suppressed to a greater degree in the initial link preceding the unsignalled‐shock condition. Reversing the terminal‐link positions of unsignalled shock and signalled shock led to a reversal of the differential response suppression in the initial links. These results confirm previous findings that signalled shock is less aversive than unsignalled shock and extend the generality of this phenomenon from choice measures to rate measures of aversiveness.
AVOIDANCE CONDITIONING WITH SHOCK CONTINGENT UPON THE AVOIDANCE RESPONSE1
Authors: Lambert Joseph V. , Bersh Philip J. , Hineline Philip N. , Smith G. David
Published: March 2006

Rats learned either a lever‐press response, a shuttle response or a one‐way crossing response, which produced one immediate shock but was instrumental in avoiding five identical shocks scheduled to occur later. These responses were acquired both with and without support of an escape contingency. These results support shock‐frequency reduction as a sufficient condition for the acquisition and maintenance of avoidance.