Stimulus Preexposure, Comparison, and Changes in the Associability of Common Stimulus Features

In four experiments, rats received preexposure either to both of two compound flavours (AX and BX), or to just one (BX). Experiment 1 demonstrated a perceptual learning effect, showing that, for animals given preexposure to both flavours, an aversion conditioned to AX generalized only poorly to BX. Subsequent experiments assessed the properties of the common feature, X. Experiment 3 showed that the two preexposure treatments did not differ in the extent to which they produced habituation of the neophobia evoked by X. Experiment 2 showed that conditioning to X proceeded more rapidly in subjects given preexposure to both AX and BX than in subjects preexposed to BX alone. In Experiment 4, a similar effect was found when the elements of the compounds were presented serially. It is concluded that the perceptual learning effect of Experiment 1 occurs in spite of the fact that preexposure to two stimuli tends to maintain the associability of their common elements.     

The Reinforcing Effect of a Differentiating Stimulus

Twenty Sprague Dawley rats, aged 22 to 26 months were given subcutaneous injections of 4.5 mg/kg methylphenidate or distilled water. Twelve minutes after the single injection was given, rats began 90 trials of avoidance conditioning. Drug animals made significantly more correct responses than did the control animals. Results indicate that use of methylphenidate in aged rats improved avoidance learning.     

Stimulus Equivalence and The Blocking Effect

The Psychological Record - The purpose of this experiment was to examine the blocking effect within the context of a stimulus equivalence paradigm. Ten subjects were provided with a prior history...     

The Effect of Prior Fear Levels on UCS-expectancy Ratings to a Fear-relevant Stimulus

This study investigated the effect of levels of prior fear to a fear-relevant stimulus on UCS expectancy ratings in a threat conditioning procedure. The results suggested that UCS-expectancy ratings are independently influenced by both the nature of the stimulus (whether it is fear-relevant or fear-irrelevant) and the level of prior fear to the stimulus. Furthermore, significantly higher UCS-expectancy levels caused by prior fear and stimulus type were accompanied in some stages of the experiment by greater magnitudes of skin conductance responses during the stimulus.     

复合运动刺激视觉追踪的初步研究

本实验采用多目标追踪和复合刺激研究范式,将注意追踪和知觉的整体优先性两个研究领域中存在的知觉组织规律相结合,对单一和多个复合刺激进行注意追踪研究.结果表明:在单一或多个复合刺激追踪过程中,同样遵循静态知觉组织原则;不同知觉组织形式对知觉加工有不同的影响,突出的颜色变化可以促进知觉组织加工.     

The Effect of Delayed Responding on Stroop-Like Task Performance Among Preschoolers

Forty-four preschoolers completed 2 conditions of a Stroop-like procedure (e.g., saying “boat” for car and “car” for boat) that differed in whether a 3-s delay was imposed before responding. The test card was visible during the delay period for half of the children and occluded for the other children. Preschoolers’ interference control was significantly improved in the delay condition. There was no difference between the two delay variants (test card visible or occluded). Children were more prone to interference as testing progressed regardless of whether the delay was present. These results suggest that delays effectively reduce interference by reducing the potency of the competing response during test trials, although memory demands may moderate the effectiveness of delays.     

Stimulus control of responding during a fixed-interval reinforcement schedule

During training sessions, pecks by pigeons on a response key illuminated by a vertical line of white light resulted in reinforcement and an ensuing blackout according to a fixed-interval schedule. Training sessions were followed by dimensional stimulus control test sessions during which the orientation of the line present throughout the fixed interval was varied. Inverted U-shaped (excitatory) gradients of responding, with maximum responding occurring in the presence of the vertical line, were observed during the terminal part of the fixed interval. U-shaped (inhibitory) gradients of responding, with minimum responding occurring in the presence of the vertical line, were observed during the early part of the fixed interval when the preceding interval had terminated with reinforcement and blackout but not when the preceding interval had terminated with blackout only. These results suggest that the dimensional control by the stimulus present throughout the fixed interval is of a conditional variety. Whether the fixed-interval stimulus exerts inhibitory or excitatory dimensional control depends upon the presence and absence, respectively, of stimuli associated with reinforcement.     

Responding during reinforcement delay in a self-control paradigm.

Eight pigeons chose between a small, immediate reinforcer and a large, increasingly delayed reinforcer. Responding during the large-reinforcer delays was examined. During large-reinforcer delays, pecks on one key produced the small, immediate reinforcer; pecks on the other key had no effect. Thus, a pigeon could reverse its initial choice of the large, delayed reinforcer, or it could maintain its original choice. Pigeons that made a relatively high number of initial large-reinforcer choices tended to maintain these choices, and those pigeons that actually received a relatively high number of large reinforcers, tended to respond more frequently on the ineffective key during the delay periods. The findings suggest that some previous studies of self-control training in pigeons may have resulted in increased self-control partially due to a lack of opportunity for the pigeons to change their choices.     

The Influence of Retention Interval on the US Preexposure Effect: Changes in Contextual Blocking over Time

A number of studies manipulating the length of the interval between conditioning and testing indicate spontaneous recovery from overshadowing, suggesting that certain instances of overshadowing represent a deficit in memory retrieval rather than a failure of animals to form an association between the overshadowed stimulus and the US. The present series of experiments examined the influence of lengthening the retention interval on blocking, another stimulus selection phenomenon that is typically interpreted as an acquisition deficit. The results indicated that when subjects were tested shortly (3 days) after training conditioning to a taste blocked subsequent conditioning to an odor conditioned in compound with that taste (Experiment 1), whereas prior conditioning to an odor did not block subsequent conditioning to a taste conditioned in compound with that odor (Experiment 2). This pattern of results was essentially unchanged when testing occurred at a longer (21-day) retention interval. However, there was evidence of a US preexposure effect in Experiment 2 when subjects in the US ONLY control condition were tested at the 3-day retention interval, but not when testing occurred 21 days after conditioning. Experiments 3 and 4 examined whether this loss of the US preexposure effect over time might actually represent a change in the degree of contextual blocking as the retention interval is lengthened. Exposure to the conditioning context either during the interval between Phase 1 and Phase 2 of conditioning (Experiment 3) or prior to Phase 1 of conditioning (Experiment 4) alleviated this US preexposure effect suggesting that the loss of the US preexposure effect as the retention interval is lengthened observed in Experiment 2 is due to changes in the degree of blocking by contextual stimuli over time. The results are discussed in terms of differential susceptibility of forgetting of two functional roles played by a contextual stimuli in the current situation-context as a CS and context as a retrieval cue for other CS-US associations.     

Establishing Transfer of Compound Control in Children: A Stimulus Control Analysis

The Psychological Record - Five-year-old children received training on four symbolic match-to-sample tasks with single-element stimuli (A1-B1, A2-B2; P1-Q1, P2-Q2). Then they received training on...     

Latent Inhibition of Contextual Stimuli Reduces the US Preexposure Effect in Rats

Two experiments are reported which utilized latent inhibition of contextual stimuli prior to administering unsignaled presentations of the Us in an attempt to further assess the role of contextual stimuli in the US preexposure effect. Specifically in Experiment 1, rats received either 0-, 5-, 10-, or 15-minute exposure to the context in which the unsignaled Uss were to occur (latent inhibition). Following preexposure to the US, animals were trained in a CER paradigm with a tone CS. Measures of suppression to the tone indicated that the greatest US preexposure effect occurred in the 0 group and that no US preexposure effect was evident in the 15 group. Experiment 2 includec two important control groups which were omitted in Experiment 1 (no US preexposures) and an additional dependent variable (time to initiate licking) to measure fear to contextual stimuli. These results are discussed in terms of the role context conditioning may play in US preexposure.

     

Effects of Responding or Not Responding to Hecklers on Audience Agreement with a Speaker

The hypothesis that responding to hecklers would produce more agreement with a speaker than not responding, stemmed from commodity theory (Brock, 1968). One hundred twenty-one introductory speech students participated in what they were told was a "speech workshop" (not a psychology experiment). Two types of responding to live hecklers were used: In one, the speaker responded in a calm, relevant manner; in the other, she responded in an upset, irrelevant manner. In a third condition, the speaker did not respond to the heckles. There were two additional conditions: One in which the speaker responded to interruptions, and a further control in which there were neither heckles nor interruptions. In these five conditions, the speaker either argued for or against the audience's position. Regardless of whether or not the speaker's position agreed with the audience's, upset-irrelevant responding decreased the speaker's persuasiveness over making no response, while calm-relevant responding tended to enhance persuasiveness. Finally, in agreement with all other empirical studies, it was clearly shown that heckling, whether responded to or not, did not improve the speaker's effectiveness.     

The Stimulus as a Series of Contexts for Practice

This study of concept attainment investigated the hypothesis that different forms of hypothesis (conjunctive/disjunctive) presented by the S would meet different arrays of contingencies. Sixty Ss, aged between 16 and 50, of both sexes, of various occupations, but all in the top 2% to 3% of the United Kingdom population in terms of intelligence, each attempted two concept-attainment problems, in the reception mode, with both attributes and form of concept unknown. The experimental material was that developed by Neisser and Weene, with concepts taken from their Level II. Instances were presented one by one on a typewritten sheet, on which the S was required to write an hypothesis after the presentation of each instance. Different types of contingency (positive and negative; confirming and infirming) differed in difficulty; different forms of hypothesis met characteristically different arrays of the four types of contingency. The results support the hypothesis above and call in question Bruner, Goodnow, and Austin's conclusion that the most important type of contingency is always the positive infirming.     

Stimulus generalization and delay of reinforcement during one component of a multiple schedule

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.     

不同材料语义知觉对抓握运动影响的行为研究

语言与抓握运动对应脑皮层之间的联系已得到大量神经生理学研究的证明,但两者外显行为的联系并未得到系统的验证。本研究以二维物体为刺激材料,通过比较词语知觉和图片知觉对抓握运动的影响,探讨语义知觉对抓握运动的影响。结果发现:词语知觉对抓握运动存在语义效应,即知觉语义为"大"的词语时其最大抓握孔径大于知觉语义为"小"的词语时的情况,而图片知觉无此效应。     

The Effects of a Pretrained Excitatory Stimulus on Schedule-Induced Polydipsia in the Rat

The purpose of the present study was to test two predictions derived from the application of Pavlovian conditioning principles to the schedule-induced polydipsia (SIP) phenomena. The first prediction was that a pretrained excitatory signal for pellet delivery would facilitate the development of SIP. A second prediction was that phenomena which are typically observed in Pavlovian conditioning experiments, such as learned irrelevance, latent inhibition, and the US preexposure effect, would also be observed in the SIP paradigm. The results indicated that a group given excitatory pretraining to a tone failed to develop SIP more rapidly than controls when this tone was used to signal pellet deliveries during SIP training. However, learned irrelevance, latent inhibition, and the US preexposure effect were demonstrated. Thus, these data generally support the predictions derived from the Pavlovian conditioning view of SIP.

     

A Multimethod Examination of the Effect of Insomnia Symptoms on Anxious Responding to a Social Stressor

A growing number of studies identify insomnia symptoms as a potential risk factor for the development of anxiety disorders. However, little research has examined potential mechanisms through which insomnia could confer increased risk for anxiety. A separate line of literature suggests sleep is necessary for adaptive emotional and behavioral responding to stressors, a potential mechanism linking insomnia symptoms to anxiety risk. To test whether insomnia symptoms affect emotional and behavioral responding to an anxiety-relevant stressor, the current study recruited a sample of 99 undergraduates with varying levels of insomnia symptoms. Participants completed self-report and psychophysiological measures before, during, and after an impromptu speech task. Results indicated that, after covarying for negative affectivity, increased insomnia symptoms were significantly associated with elevated anticipatory anxiety and skin conductance response prior to the speech, and increased skin conductance response, emotion regulation difficulties, and safety aid use during the speech. Taken together, results provide evidence for the notion that insomnia symptoms are associated with maladaptive emotional and behavioral responding to an anxiety-relevant stressor.     

The Quantal Interpretation of Stimulus Control

The Psychological Record -