The effect of intertrial conditioned stimuli in autoshaping

Three autoshaping experiments, using pigeon subjects, examined the effect of presenting an S+ or an S- on acquisition to a different conditioned stimulus (CS). Experiment 1 found that signalling intertrial food with an S+ or an S- allowed acquisition of responding to the target-CS; however, that acquisition was slower when the signal was the S+. Experiment 2 found that even when the S+ or S- were presented without food in the intertrial interval, acquisition was slower in the group receiving the S+. Experiment 3 found that a similar, but weaker effect occurred when the S+ or S- stimuli were presented in the session prior to target-CS training, rather than intermixed. These results have implications for the interpretation of experiments that use a signalling manipulation to assess the interaction of CS and context in Pavlovian conditioning; they suggest that signalling unconditioned stimuli (USs) may have consequences other than that of modulating context-US learning.     

Effect of information feedback upon intertrial consistency of time judgment

Male college students made verbal estimations of time intervals ranging from five to 80 sec on six blocks of five trials. Some subjects were given information feedback (IF) about judgment errors after each trial and the remaining subjects were given no IF. Judgments of the no-IF group changed from initial overestimations to final underestimations of the intervals across blocks of trials. Judgments of the IF group did not significantly change across blocks. In the no-IF group, each block of trials correlated strongest with immediately adjacent blocks; i.e., the correlation matrix had a superdiagonal form. Interblock correlations were weakened by IF, and the superdiagonal form was not obtained in the matrix of the IF group. Previous theories of the superdiagonal form are considered inadequate to explain these results. An alternative hypothesis, based on changing decision criteria with blocks, which IF attenuates, is proposed to explain these data.     

Role of conditioned contextual stimuli in reinstatement of extinguished fear

If the unconditioned stimulus (US) is presented independently of the conditioned stimulus (CS) following extinction, the conditioned response may be reinstated to the CS. Three experiments are reported that suggest that reinstatement is mediated by conditioning to contextual stimuli that are present during both US presentation and testing. Shocks presented to rats following the extinction of conditioned suppression reliably reinstated suppression to the CS, but only when they were presented in the context in which testing was later to occur. Reinstatement was also reversed by extinguishing fear to the context through nonreinforced exposure to the context between shock presentation and testing. Reinstatement was obtained in these experiments in spite of procedures that have been used in the past to minimize the influence of context conditioning. Moreover, fear of the context was never detected directly by depressed bar-press rates in the absence of the CS. The results do not support the hypothesis that reinstatement results from an increment in the strength of a memory of the US that has been weakened during extinction. Problems inherent in controlling and detecting levels of context conditioning that may influence behavior toward nominal CSs are discussed.     

Salient stimuli in advertising: the effect of contrast interval length and type on recall

Salient auditory stimuli (e.g., music or sound effects) are commonly used in advertising to elicit attention. However, issues related to the effectiveness of such stimuli are not well understood. This research examines the ability of a salient auditory stimulus, in the form of a contrast interval (CI), to enhance recall of message-related information. Researchers have argued that the effectiveness of the CI is a function of the temporal duration between the onset and offset of the change in the background stimulus and the nature of this stimulus. Three experiments investigate these propositions and indicate that recall is enhanced, providing the CI is 3 s or less. Information highlighted with silence is recalled better than information highlighted with music.     

A short intertrial interval facilitates acquisition of context-conditioned fear and a short retention interval facilitates its expression

Rats were shocked in a context on two occasions and then tested for fear reactions as indexed by freezing. Rats spent the interval between conditioning trials and between conditioning and test in their home cages. A short interval between context-conditioning trials or between trials involving a discrete conditioned stimulus (CS) produced better learning than longer intervals. A short retention interval between conditioning and test produced better performance than longer intervals. The effects of the intertrial interval on learning are the opposite of those reported previously and are opposite to those predicted by contemporary learning theories. The effects of the training to test interval on performance are predicted by Wagner's sometimes opponent process (SOP) theory (Wagner, 1981).     

The interactive effects of stimulus generalization decrement and contextual pre-exposure cues upon fear incubation

Models of fear incubation may be described as explanations for the interference of Pavlovian extinction. From this perspective, the effects of several parameters upon the incubation phenomenon were examined. Fear incubation was found to be attenuated by manipulations associated with stimulus generalization decrement (Experiment 1), as well as pre-exposure manipulations (Experiment 2). These findings were incorporated within existing models of incubation.     

The effect of feedback sign on task performance depends on self-concept discrepancies

Control theories claim that information about performance is often used by multiple goal systems. A proposition tested here was that performance information can create discrepancies in self-concept goals, directing cognitive resources away from the task goal system. To manipulate performance information, 160 undergraduates were given false positive or false negative normative feedback while working on a task that did or did not require substantial cognitive resources. Half of the participants were then given an opportunity to reaffirm their self-concepts following feedback, whereas half were not. Feedback sign positively related to performance only for those working on the cognitively intense task and not given a chance to reaffirm. Otherwise, feedback sign was negatively related to performance, albeit weakly.     

The effect of feedback on luminance thresholds for peripherally presented stimuli

The effect of a central task on peripheral vision was determined by obtaining absolute luminance thresholds for peripherally presented stimuli. A competing central task was provided by interrupting the fixation light and requiring the S to reilluminate it. Data were obtained over five sessions, with feedback information provided on each trial. Thresholds were highest for the initial session and declined as a function of practice. The magnitude of the change depended upon the interruption rate. When central and peripheral stimuli compete for attention, priority is given initially to the central task, but, with practice, the differences are reduced.     

The face-specific proportion congruency effect: social stimuli as contextual cues

Previous research shows that larger interference is observed in contexts associated with a high proportion of congruent trials than in those associated with a low proportion of congruent trials. Given that one of the most relevant contexts for human beings is social context, researchers have recently explored the possibility that social stimuli could also work as contextual cues for the allocation of attentional control. In fact, it has been shown that individuals use social categories (i.e., men and women) as cues to allocate attentional control. In this work, we go further by showing that individual faces (instead of the social categories they belong to) associated with a high proportion of congruent trials can also lead to larger interference effects compared to individual faces predicting a relatively low proportion of congruent trials. Furthermore, we show that faces associated with a high proportion of congruent trials are more positively evaluated than faces associated with a high proportion of incongruent trials. These results demonstrate that unique human faces are potential contextual cues than can be employed to apply cognitive control when performing an automatic task.     

The role of context in intertrial interval effects in autoshaping

Two experiments evaluated the role of differential conditioning of the context in mediating the effect of intertrial interval (ITI) in autoshaping. In Experiment 1 pigeons were given acquisition with two keylights, each presented in a particular context. A given keylight/context combination had associated with it either a short (10-sec) or a long (2-min) ITI. Acquisition was more rapid with the long ITI. Tests with those keylights in a common third context indicated that the longer ITI had resulted in greater conditioning. On the other hand, pigeons trained on keylights with mixed ITIs in a third context evoked more responding when they were tested in the short ITI context compared with the long ITI context. That suggests that a context with a history of a short ITI enhances performance. In Experiment 2, two keylights were initially conditioned with mixed ITIs and then extinguished in different contexts under different ITI lengths. Extinction was more rapid for the keylight presented with a short ITI. That difference persisted when the keylights were tested with mixed ITIs in a common third context, suggesting a difference in associative strength of the keylights. The results are interpreted in terms of differential context conditioning resulting in differences in learning about the keylight.     

The contextual malleability of approach-avoidance training effects: approaching or avoiding fear conditioned stimuli modulates effects of approach-avoidance training

Previous research showed that the repeated approaching of one stimulus and avoiding of another stimulus typically leads to more positive evaluations of the former stimuli. In the current study, we examined whether approach and avoidance training (AAT) effects on evaluations of neutral stimuli can be modulated by introducing a regularity between the approach-avoidance actions and a positive or negative (feared) stimulus. In an AAT task, participants repeatedly approached one neutral non-word and avoided another neutral non-word. Half of the participants also approached a negative fear-conditioned stimulus (CS+) and avoided a conditioned safe stimulus (CS?). The other half of the participants avoided the CS+ and approached the CS?. Whereas participants in the avoid CS+ condition exhibited a typical AAT effect, participants in the approach CS+ condition exhibited a reversed AAT effect (i.e. they evaluated the approached neutral non-word as more negative than the avoided non-word). These findings provide evidence for the malleability of the AAT effect when strongly valenced stimuli are approached or avoided. We discuss the practical and theoretical implications of our findings.     

The influence of intertrial interval food on extinction and devaluation in chain schedules

The authors exposed pigeons to 2 equal 3-link chains by using variable-interval schedules of reinforcement. An intertrial interval (ITI) bisected by free food separated the chains. After baseline training, the authors presented terminal links in a successive discrimination to devalue 1 terminal link: The authors reinforced responses to 1 terminal link and extinguished responses to the other. The authors then presented full chains in extinction, except that they continued to deliver free food during the midpoint of the ITI. There were 2 principal findings. First, across all extinction conditions, responding decreased but did not extinguish. Second, when extinction testing revealed a terminal link devaluation effect in the 3rd condition, responding to the initial link was affected, but not middle-link responding. Overall, the results suggested that ITI food presentations can exert a substantial effect on responding in 3-link chain schedules, and they appear to influence both the pattern of extinction and devaluation effects.     

反馈间隔影响反馈加工：整合行为和电生理研究的视角

反馈在现实生活中扮演着重要角色, 通过反馈信息进行学习是人类获取知识和技能的有效手段。反馈间隔是指个体行为发生到反馈刺激呈现之间的时间间隔。在反馈加工过程中, 反馈间隔是一个重要影响因素, 但反馈间隔影响反馈加工的研究结果不一。对反馈间隔影响反馈加工的行为和电生理研究分别做了介绍, 对结果出现差异的原因进行了分析。未来的研究应考虑结合行为研究与电生理研究, 并统一反馈间隔的操作定义。