Additional-delay schedules: A continuum of temporal contingencies by varying food delay

Pigeons performed on discrete-trial, temporally defined schedules in which the food delay (D) was adjusted according to the latency of the key peck (X) and two schedule parameters (t and A). The schedule function was D = A(t − X), where D is the experienced delay between a response and a reinforcer. The schedule parameter t is the maximum value below which the present contingencies occur. A is the additional delay to reinforcement for each second the response latency is shorter than the t value. When A = 0 s, the schedule is a continuous reinforcement schedule with immediate reinforcement. When A = 1 s, the schedule is a conjunctive fixed-ratio 1 fixed-time t-s schedule. When A approaches infinity, the schedule becomes a differential reinforcement of long latency schedule. The latencies for subjects with t = 10 s and t = 30 s were observed with the present schedules having seven values for A between 0 s and 11 s. In addition, the latencies for subjects for which t = 30 s were observed at an A value of 31 s to 41 s. As the A value increased, the latencies approached the t value for subjects for which t = 10 s. The latencies for 30-s-t subjects did not approach t, even when the A value was 41 s. The latencies for 10-s-t subjects at 11-s A value were longer than those under yoked conditions having exactly the same delays/interreinforcement intervals. These results demonstrated a continuum of latency related to the schedule continuum (value of A) at a small t value.     

Timeout from concurrent schedules.

Response-contingent timeouts of equal duration and frequency were added to both alternatives of unequal concurrent schedules of reinforcement. For each of 4 pigeons in Experiment 1, relative response rates generally became less extreme as the frequency of timeout increased. In Experiment 2, relative response rates consistently approached indifference as the duration of timeout was increased. Variation in time allocation was less consistent in both experiments. Absolute response rates did not vary with the timeout contingency in either experiment. In a third experiment, neither measure of choice varied systematically when the duration of a postreinforcement blackout was varied. In contrast to the present results, preference has been shown to vary directly with the parameters of shock delivery in related procedures. The pattern of results in the first two experiments follows that obtained with other manipulations of the overall rate of reinforcement in concurrent schedules. The results of the third experiment suggest that an intertrial interval following reinforcement is not a critical feature of the overall rate of reinforcement.     

Determinants of pigeons' waiting time: Effects of interreinforcement interval and food delay

Four pigeons performed on three types of schedules at short (i.e., 10, 30, or 60 s) interreinforcement intervals: (a) a delay-dependent schedule where interreinforcement interval was held constant (i.e., increases in waiting time decreased food delay), (b) an interreinforcement-interval-dependent schedule where food delay was held constant (i.e., increases in waiting time increased interreinforcement interval), and (c) a both-dependent schedule where increases in waiting time produced increases in interreinforcement interval but decreases in food delay. Waiting times were typically longer under the delay-dependent schedules than under the interreinforcement-interval-dependent schedules. Those under both-dependent schedules for 1 subject were intermediate between those under the other two schedule types, whereas for the other subjects waiting times under the both-dependent procedure were similar either to those under the delay-dependent schedule or to those under the interreinforcement-interval-dependent schedule, depending both on the subject and the interreinforcement interval. These results indicate that neither the interreinforcement interval nor food delay is the primary variable controlling waiting time, but rather that the two interact in a complex manner to determine waiting times.     

快速书写条件下硬笔笔迹变量与认知及个性特征的关系

以圆珠笔为书写工具．北京市某中学高一学生为被试,有效数据169人．探讨了在快速抄写条件下,笔迹书写特征与认知及个性的关系：18个笔迹变量可抽取笔压、结构、特征、字体和空间五个反映字的书写特征的因素;书写特征与认知因素间,横、竖笔压与概念形成速度。整篇压与视力追踪、字位与眼手协调相关显著;横笔压与16PF测验中的畏缩退怯——冒险敢为有正相关;竖笔压与艾森克个性因素的N有高相关。     

Schedule interactions involving punishment with pigeons and humans

The principal aim of the present experiments was to assess whether punishment increased or decreased the rate of unpunished behavior (contrast and induction, respectively) for which reinforcement rate was held constant, with physical and nonphysical punishers (electric shock and response cost), pigeon and human subjects, signaled and unsignaled components (multiple and mixed schedules), and the presence or absence of a blackout period between components. Across the three experiments there were 20 punishment conditions. Induction was found in nine of those, less consistent response-rate reduction was found in three, contrast was found in four, and in four there was no change in responding from conditions without punishment. Contrast occurred consistently only with multiple schedules during the first exposure to electric-shock punishment. Induction and no change, however, were found with every combination of the independent variables studied. Four conclusions regarding the interactions between punished and unpunished responding emerged from the present results: (a) Both contrast and induction occurred with the reinforcement rate held constant and a blackout between components, (b) induction was more common than contrast, (c) contrast occurred only in the presence of a stimulus different from that correlated with the punisher, and (d) contrast diminished with prolonged exposure to punishment. None of the current theoretical accounts of punishment contrast can explain the present results.     

MEMORY PROCESSES IN DELAYED SPATIAL DISCRIMINATIONS: RESPONSE INTENTIONS OR RESPONSE MEDIATION?

Pigeons were trained on a pair-comparison task in which left versus right choices were reinforced following different sequences of two center-key stimuli. Choice accuracy was higher when retention intervals occurred after the entire sequence than when they separated the two stimuli comprising it, and this effect occurred independently of whether the initial and terminal stimuli came from the same or different dimensions. The initial stimulus from the prior trial was a source of proactive interference only in groups for which the retention interval separated the two sequence stimuli. By contrast, differential delay-interval behavior was observed only in groups for which the retention interval followed presentation of the entire sequence. These results indicate that coding processes in delayed discriminations are influenced by the location of the retention interval, and that response mediation affects retention performances if the reinforced choice can be determined prior to the interval.     

Response-independent Events In The Behavior Stream

The metaphor of the behavior stream provides a framework for studying the effects of response-independent food presentations intruded into an environment in which operant responding of pigeons was maintained by variable-interval schedules. In the first two experiments, response rates were reduced when response-independent food was intruded during the variable-interval schedule according to a concomitantly present fixed-time schedule. These reductions were not always an orderly function of the percentage of response-dependent food. Negatively accelerated patterns of key pecking across the fixed-time period occurred in Experiment 1 under the concomitant fixed-time variable-interval schedules. In Experiment 2, positively and negatively accelerated and linear response patterns occurred even though the schedules were similar to those used in Experiment 1. The variable findings in the first two experiments led to three subsequent experiments that were designed to further illuminate the controlling variables of the effects of intruded response-independent events. When the fixed and variable schedules were correlated with distinct operanda by employing a concurrent fixed-interval variable-interval schedule (Experiment 3) or with distinct discriminative stimuli (Experiments 4 and 5), negatively accelerated response patterns were obtained. Even in these latter cases, however, the response patterns were a joint function of the physical separation of the two schedules and the ratio of fixed-time or fixed-interval to variable-interval schedule food presentations. The results of the five experiments are discussed in terms of the contributions of both reinforcement variables and discriminative stimuli in determining the effects of intruding response-independent food into a stream of operant behavior.     

8─11个月婴儿迂回行为发展特点与学习能力的研究

采用程序标准化的婴儿迂回行为测验,探讨了２４４名８－１１个月婴儿的迂回行为发展特点及学习能力。结果表明：（１）８－１１个月婴儿的迂回行为水平表现出随婴儿月龄的增长而提高的趋势。（２）８－１１个月的婴儿具有从反复尝试中学会迂回行为的可能性,其中９、１０个月的婴儿的学习可能性较大,而８个月婴儿的学习可能性较小。（３）８－１１个月婴儿的学习速度随月龄增大而提高。     

Predicting and scaling hens' preferences for topographically different responses

Six hens were exposed to several concurrent (second-order) variable-interval schedules in which the response requirements on the alternatives were varied. The response requirements were one key peck versus five key pecks, one key peck versus one door push, and five key pecks versus one door push. Response- and time-allocation ratios undermatched the obtained reinforcement ratios but were well described by the generalized matching law. Time and response bias estimates from two pairs of response requirements were used to predict bias in the third pairing. The predicted values were close to those obtained; this result supports the notion that both numerically and topographically different responses act as constant sources of bias within the generalized matching law. The differences between the response and time biases could be accounted for by the different times needed to complete each response requirement. The results also suggest that the door push is a useful operant for research with domestic hens.     

Contrast and reallocation of extraneous reinforcers as a function of component duration and baseline rate of reinforcement

Four pigeons responded on multiple schedules arranged on a “main” key in a two-key experimental chamber. A constant schedule component was alternated with another component that was varied over conditions. On an extra response key, conjoint schedules of reinforcement that operated in both components were arranged concurrently with the multiple schedule on the main key. On the main key, changes in reinforcement rate in the varied component were inversely related to changes in response rates in the constant component (behavioral contrast). On the extra key, some reinforcers were reallocated between components, depending on the schedules in effect on the main key in the varied component. In the varied component, the obtained rates of reinforcement on the extra key were inversely related to main-key reinforcement rate. In the constant component, extra-key reinforcer rates were positively related to main-key reinforcer rates obtained in the varied component, and were not a function of response rates on the extra key. In two comparisons, the rate at which components alternated and the value of the main-key schedule in the constant component were varied. Consistent with earlier work, long components reduced the extent of contrast. Reductions in contrast as a function of component duration were accompanied by similar reductions in the extent of reinforcer reallocation on the extra key. In the second comparison, lowering the rate of reinforcement in the constant component increased the rate at which extra-key reinforcers were obtained, reduced the extent of reinforcer reallocation, and reduced contrast. Overall, the results are consistent with the suggestion that some contrast effects are due to the changes in extraneous reinforcement during the constant component, and that manipulations of component duration, and manipulations of the rate of reinforcement in the constant component, affect contrast because they influence the extent of extraneous reinforcer real-location.