Yoking Procedure Research Articles

Punishment in training contexts decrease operant renewal in zebrafish (Danio rerio)

A previously reinforced and then extinguished response can recur following a change in the environmental context despite extinction remaining in effect, often referred to as renewal. Using zebrafish, the present study examined how adding a punishment contingency to the training context affected the level of renewal. In Context A, responding was reinforced during Phase 1a and then exposed to either reinforcement plus punishment or reinforcement only in Phase 1b. During Phase 2, we extinguished responding in Context B and extinction remained in effect when returning to Context A during Phase 3. Responding was lower with than without the punishment history in Phase 1b after controlling reinforcement rates with a yoking procedure. Thus, the history of punishment produced lower levels of renewal compared with the absence of punishment. These findings join others suggesting contexts mediate the effects of reinforcement, extinction, and punishment contingencies.

Learning to avoid looking: Competing influences of reward on overt attentional selection

Pairing a stimulus with large reward increases the likelihood that it will capture attention and eye-gaze, even when such capture has negative consequences. This suggests that a stimulus’s signalling relationship with reward (the co-occurrence of that stimulus and reward) has a powerful influence on attentional selection. In the present study, we demonstrate that a stimulus’s response relationship with reward (the reward-related consequences of attending to that stimulus) can also exert an independent, competing influence on selection. Participants completed a visual search task in which they made a saccade to a target shape to earn reward. The colour of a distractor signalled the magnitude of reward available on each trial. For one group of participants, there was a negative response relationship between making a saccade to the distractor and reward delivery: looking at the distractor caused the reward to be cancelled. For a second group, there was no negative response relationship, but an equivalent distractor–reward signalling relationship was maintained via a yoking procedure. Participants from both groups were more likely to have their gaze captured by the distractor that signalled high reward versus low reward, demonstrating an influence of the signalling relationship on attention. However, participants who experienced a negative response relationship showed a reduced influence of signal value on capture, and specifically less capture by the high-reward distractor. These findings demonstrate that reward can have a multifaceted influence on attentional selection through different, learned stimulus-reward relationships, and thus that the relationship between reward and attention is more complex than previously thought.

Generalization of learned variability across multiple dimensions in humans

This study examined whether trained variability would generalize across dimensions of the target response. Two experiments used a computerized rectangle drawing task that required participants to click and drag a mouse cursor to create rectangles on a computer screen. In Experiment 1, one group received points when successive rectangles varied in their size, shape and location (VAR), another group were yoked to the VAR group and received points that were allocated to them using a yoking procedure (YOKE), regardless of the variability in the size, shape or location of the rectangle drawn. Variability was higher for a dimension when variability on that dimension was directly reinforced. In Experiment 2, three groups of participants received points when rectangles varied on two dimensions; each group differed in the two dimensions that required variation. Variability was again higher for the reinforced dimensions for two of the three groups. Comparison with the YOKE group showed that the variability on those dimensions where variability was not directly reinforced was affected by reinforcement for variability on the other dimensions. Specifically, the variability in Shape and Location was significantly higher when these two dimensions occurred with other dimensions where variability was reinforced (as in Experiment 2) compared to when they were not required to vary (as in the YOKE group). This suggests that, for these two groups, the reinforced variability on the other two dimensions generalized to the third dimension. Implications of this finding to our understanding of factors that promote behavioral variability are discussed.

The efficiency and efficacy of equivalence-based learning: A randomized controlled trial.

Because it employs an emergent-learning framework, equivalence-based instruction (EBI) is said to be highly efficient, but its presumed benefits must be compared quantitatively with alternative techniques. In a randomized controlled trial, 61 college students attempted to learn 32 pairs of proprietary and generic drug names using computer-based match-to-sample presentations of auditory and written drug names. Students who received EBI experienced pairings based on stimulus equivalence theory, and they mastered the material quickly. Control-group students practiced relations drawn at random from those that the EBI group learned via training or emergence. Students in the criterion-control group required many more trials to achieve the same accuracy as the EBI group. By way of a yoking procedure, students in the trial-control group received the same number of trials as the EBI students but achieved poorer accuracy and little mastery. Thus, EBI was more efficient and effective than unstructured presentation.

Timing in response-initiated fixed intervals.

Different events can serve as time markers that initiate intervals in schedules of reinforcement. Pigeons were exposed to fixed-interval (FI) schedules in which the onset of the interval was signaled by the illumination of a key light or initiated by a peck to a lighted key. Food was delivered following the first response after the interval elapsed. In Experiment 1, three pigeons were exposed to a multiple schedule. One component was a standard FI schedule: Key light illumination signaled the onset of the interval. The other component was a response-initiated fixed-interval (RIFI) schedule: The first key-peck response determined the onset of the interval. In Experiment 2, three pigeons were exposed to a multiple FI-RIFI schedule of reinforcement and on occasional trials food was not delivered (i.e. "no-food" or "peak trials"). A yoking procedure equated reinforcement rates between the schedule types in both experiments. Absolute response rates early in the intervals were higher in the RIFI schedules of both experiments. Normalized response-rate gradients, ogive fits of normalized response gradients, and breakpoints were not systematically different for the schedule types in Experiment 1, indicating similar patterns of responding between interval onset and food delivery. However, during peak trials in Experiment 2 the duration of responding at a high rate was longer for RIFI schedules than FI schedules. This suggests that timing precision was reduced in the RIFI schedules and that relative "distinctiveness" of a time marker may determine its efficacy.

Control over the scheduling of simulated office work reduces the impact of workload on mental fatigue and task performance.

Two experiments tested the hypothesis that task-induced mental fatigue is moderated by control over work scheduling. Participants worked for 2 hr on simulated office work, with control manipulated by a yoking procedure. Matched participants were assigned to conditions of either high control (HC) or low control (LC). HC participants decided their own task scheduling, whereas LC participants had to follow these fixed schedules. For Experiment 1, fatigue was higher in LC participants who worked harder, so Experiment 2 compared control effects in high- and low-workload groups. As predicted, the impact of workload was reduced under HC conditions, for subjective fatigue, and most secondary tasks and aftereffects. The findings are interpreted within the framework of compensatory control theory.

Rats' performance on variable-interval schedules with a linear feedback loop between response rate and reinforcement rate.

Three experiments investigated whether rats are sensitive to the molar properties of a variable-interval (VI) schedule with a positive relation between response rate and reinforcement rate (i.e., a VI+ schedule). In Experiment 1, rats responded faster on a variable ratio (VR) schedule than on a VI+ schedule with an equivalent feedback function. Reinforced interresponse times (IRTs) were shorter on the VR as compared to the VI+ schedule. In Experiments 2 and 3, there was no systematic difference in response rates maintained by a VI+ schedule and a VI schedule yoked in terms of reinforcement rate. This was found both when the yoking procedure was between-subject (Experiment 2) and within-subject (Experiment 3). Mean reinforced IRTs were similar on both the VI+ and yoked VI schedules, but these values were more variable on the VI+ schedule. These results provided no evidence that rats are sensitive to the feedback function relating response rate to reinforcement rate on a VI+ schedule.

Effects of the Kappa-opioid Receptor Agonist, U69593, on the Development of Sensitization and on the Maintenance of Cocaine Self-administration

Previous studies showed that prior administration of kappa-opioid agonists decreased the development of sensitization to some of the behavioral effects of cocaine. The present study sought to determine whether the development of sensitization to cocaine's reinforcing effects was also sensitive to antagonism by kappa-opioid agonists. During a pretreatment phase, the kappa-opioid agonist, U69593 (0.0 or 0.32 mg/kg) was administered prior to (1) 2 daily injections of cocaine (0.0 or 20.0 mg/kg), or (2) cocaine or saline administered via a yoking procedure. Cocaine pretreatment decreased the latency to acquisition of cocaine self-administration. However, prior administration of U69593 during the pretreatment phase failed to attenuate the development of this sensitized response to cocaine's reinforcing effect. In other groups, the effect of acute U69593 pretreatment on the maintenance of cocaine self-administration was examined during a 10 hr session. During training and testing, a stimulus was associated with each self-administered cocaine infusion for one group whereas responding of another group was reinforced by a cocaine infusion alone. On the test day, pretreatment with U69593 (0.32 mg/kg) decreased responding during each hour of the 10 hr session for the group that was reinforced with cocaine plus the cocaine-associated stimulus. U69593 failed to produce a long-lasting disruption of cocaine self-administration for rats that were trained and tested without the cocaine-associated stimulus. These data suggest that the acquisition and maintenance of cocaine self-administration are differentially sensitive to manipulations of kappa-opioid systems. Further, the disruption of cocaine self-administration by U69593 may be due to interactions with mechanisms that underlie facilitative effects of stimuli that have been associated with self-administered cocaine infusions.

Influence of the cost of responding

In three experiments, the effect of costs associated with responding on judgments of the causal effectiveness of the response was examined. In Experiment 1, the temporal interval between outcomes was matched on a variable interval (VI) and a variable ratio (VR) schedule. When each response was made at some "cost," and outcomes represented some "gain" for the subject, the rating of causal effectiveness for responses was higher on the VR than on the VI schedule. This relationship was absent when the outcome was a triangle flash. In Experiment 2, the number of responses required per outcome on a VI and a VR schedule were matched, and responses on the VR schedule were rated as more causally effective. In Experiment 3, a VI-to-VR yoking procedure was used. With minimal response costs, judgments were similar on the VI and VR schedules, but with greater response costs, responses performed on the VR schedule were rated as more causally effective than those emitted on the VI schedule.

Instrumental performance on negative schedules

Three experiments examined the performance of rats pressing a lever for food reinforcement on a schedule in which high rates of response resulted in lowered rates of reinforcement (i.e. a schedule with a negative component). In Experiment 1, rats responded on a variable interval (VI) schedule with a conjoint component such that every 30 responses a reinforcement programmed by the VI schedule was cancelled. These subjects generally emitted a lower response rate than rats responding on a VI schedule yoked to the former subjects with respect to the delivery of reinforcement, although response rate differences were sometimes not large. Similar response-rate effects were obtained in Experiment 2 using a within-subject yoking procedure. In Experiment 3, reinforced interresponse times were matched on negative and VI schedules yoked in terms of reinforcement rate, and the response rate emitted in these conditions were similar. These results give support to theories of instrumental conditioning that stress the str...

Bandwidth Knowledge of Results and Motor Learning: More than Just a Relative Frequency Effect

Motor learning is facilitated when knowledge of results (KR) is presented in accordance with a goal-centred bandwidth (i.e. when the error exceeds a tolerance limit about a movement goal). However, under different conditions of the bandwidth procedure the frequency with which KR is provided is also affected—the wider the goal-centred tolerance limits, the lower the frequency of KR. Since low-KR frequency conditions also have been shown to facilitate motor learning, it is not known whether the bandwidth KR effect is a unique phenomenon in motor learning or is simply due to differences in the frequency of KR. In the present study we partitioned the effects due to bandwidth KR from the effects due to KR frequency using a yoking procedure. Results from the acquisition performance trials indicated that bandwidth procedures exerted both error reduction and performance stabilization influences on motor behaviour that exceeded the effects of the relative frequency control procedures. Bandwidth procedures further resulted in better performance consistency during retention than the relative frequency conditions. These findings were discussed in terms of how KR about movement error and KR about the correctness of movement affect the learning of motor skill.

Overshadowing and potentiation of instrumental responding in rats as a function of the schedule of reinforcement

In Experiment 1, rats trained to lever press on variable-ratio-30 (VR) and VR-10 schedules with a 500-ms signaled delay between the reinforced response and food delivery responded at a higher rate than control subjects receiving unsignaled delayed reinforcement. These results stand in contrast to previous studies using a variable interval (VI) schedule in which the signal produces a lower response rate. Experiment 2 compared VR and VI schedules using yoked control conditions. A slightly lower response rate in the signaled condition was found on VR and VI schedules. This effect was interpreted as arising from schedule differences engendered by the yoking procedure. Experiment 3, using VI 60-s and VR-30 schedules demonstrated lower responding in the signaled condition with VI and elevated responding with VR relative to control subjects that received unsignaled food presentations. These results are discussed with reference to associative and “efficiency” theories of instrumental performance.

Overshadowing of responding on ratio and interval schedules by an independent predictor of reinforcement

This experiment replicated previous demonstrations that interposing a brief stimulus between reinforced responses and the presentation of the reinforcer reduces responding maintained by intermittent reinforcement schedules. Furthermore, we could find no significant difference between the relative size of the reduction during training on ratio and interval schedules when the predictive significance of the response and stimulus was controlled by a yoking procedure.

Effects of Self-Determined and High Performance Standards on Spelling Performance:

The effects of self-determined and high performance standards were compared to a non-treatment control condition on the spelling performance of 10 special education students for an entire school year. A yoking procedure was employed whereby pupils received the same number of points, based on their average scores in Baseline, regardless of being exposed to self-determined or high performance standards. The results indicated that superior performance occurred during both self-determined or high performance standards conditions when compared to the non-treatment control condition. This effect was significant standards conditions was significant (p=>.01. Suggestions for future research and implications of the present investigation were made.

STIMULUS‐REINFORCER CONTINGENCIES AND LOCAL BEHAVIORAL CONTRAST1

Four pigeons were exposed to a series of multiple schedules of variable-interval reinforcement in which pecks were required on one key (operant key) and components were signalled on a second key (signal key). Four additional pigeons experienced identical conditions, except that a yoking procedure delivered food on variable-time schedules, with no key pecks required. One of the components of the multiple schedule was constant throughout the experiment as a variable-interval (or variable-time) 30-second schedule. Operant-key responding during the constant component was uniform throughout the component, uninfluenced by changes in the duration of the variable component, and only slightly influenced by changes in reinforcement frequency correlated with the variable component. By comparison, signal-key response rate during the constant component was highest at the onset of the component, was higher when the variable component was 60-sec long than when it was 1-sec long, and was higher when no reinforcement occurred in the variable component than when reinforcement was scheduled in the variable component. These characteristics of signal-key pecking matched characteristics of local positive behavioral contrast. These data are taken to support the "additivity theory" of behavioral contrast and to suggest that Pavlovian stimulus-reinforcer relations contribute primarily to the phenomenon of local positive contrast.

Response suppression on DRL by rats with septal damage.

The effectiveness of the differential reinforcement for low rates of responding (DRL) contingency in suppressing response rates of septal rats was investigated by using a Multi-DRL-yoked-VI (variable interval) schedule of reinforcement. The yoking procedure equated the interreinforcement times on the two schedules. Each schedule was in effect for half of each session, and the change in schedule was signaled by the presence or absence of a cue light. Schedule order and DRL delay requirement were varied. For both normal and septal rats, the response rates were higher in the VI component than the DRL component; this effect demonstrates that the responding of septals as well as normals is suppressed by the differential reinforcement of a particular class of IRTs. A sharp difference in the level of responding occurred at the point of transition from one component of the multiple schedule to the other, which provides evidence of a discrimination between the two schedules for both normals and septals. The conclusion is that the responding of septals is suppressed by the DRL contingency and not controlled solely by the density and distribution of reinforcement.

YOKED VARIABLE‐RATIO AND VARIABLE‐INTERVAL RESPONDING IN PIGEONS1

Pigeons' key pecks were maintained by variable-ratio or variable-interval schedules of food reinforcement. For pairs of pigeons in one group, variable-ratio reinforcement was arranged for one pigeon's pecks; for the second pigeon, reinforcement was arranged according to a variable-interval schedule yoked to the interreinforcement times produced by the first pigeon. For pairs of pigeons in another group, variable-interval reinforcement was arranged for one pigeon's pecks; for the second pigeon, reinforcement was arranged according to a variable-ratio schedule yoked to the interreinforcement responses produced by the first pigeon. For each pair, the yoking procedure was maintained for four or five consecutive sessions of 50 reinforcements each. In more than three-quarters of the pairs, variable-ratio response rates were higher than variable-interval rates within two sessions; in all cases, the rate difference developed within four sessions.

The sensitivity of the pigeon’s keypeck to the differential reinforcement of long interresponse times

Keypecking of pigeons was studied under differential-reinforcement-of-low-rate (DRL) and variable-interval (VI) schedules in which the interreinforcement times on the two schedules were equated by a yoking procedure. Each schedule was available for half of every session and a change of schedule was signaled by a change of key color. The value of the DRL schedule was varied from .5 to 300 sec. Response rates were always higher in the VI schedule, but within sessions there was a sharp change in response rate coincident with the change in schedule only under lower schedule values. A group without prior training was tested with a 180-sec schedule value, and it, too, developed a higher response rate during the VI schedule, showing that the effect was not dependent on prior experience under low schedule values. In all conditions except the .5- and 1-sec values of the schedule, the mean proportion of responses emitted during the VI schedule was approximately .85 of the responses emitted during both schedules. The conclusion was that the requirement of a minimum interresponse time for reinforcement may work its effect by determining which responses may occur just prior to the reinforced response and thus receive delayed reinforcement.

Preconditioning of reinforcing properties to an exteroceptive feedback stimulus

Three groups of rats were given Pavlovian preconditioning by means of a yoking procedure and subsequently trained to avoid. One group received a light stimulus during preconditioning at the same times as the master avoiding animals received an exteroceptive feedback stimulus. During the subsequent avoidance training, this group was then given the same light stimulus as a feedback stimulus on successful avoidance trials. The group learned two-way avoidance in about the same number of trials as one-way avoidance is typically learned and substantially faster than two other control groups. These data indicate that feedback stimuli develop reinforcing properties by a Pavlovian mechanism. The data of the control groups indicate that feedback stimuli do not provide “information” about responding in the present situation.

Age differences in organization and recall: The effects of training in categorization

An alternating sort/recall task was employed to train fourth graders and college students in organizational strategies. Free-sorting Ss, at both age levels, sorted a group of words into two to seven categories. Analyses of final sorting patterns indicated reliable differences between the children and adults. The organizational schemes thus developed by the free-sorting Ss were taught, by means of a yoking procedure, to other Ss. Results indicated that the recall of fourth graders was improved when they were forced to learn the sorting patterns developed by the older Ss. Similarly, impairment in the recall of college students was observed when they were required to sort according to the organization employed by the fourth graders. These findings imply that changes in organization can result in changes in recall performance.