The effects of vicarious experience and stimulus intensity on pain termination and work avoidance

The purpose of the present investigation was to evaluate the role of vicarious experience in the acquisition of pain termination and work avoidance. Fifty-six experimental subjects were randomly assigned to view a film of a model who either terminated exposure to a pain stimulus and work task after 10 sec (high-avoidant) or 70 sec (low-avoidant). Following the film presentation, subjects were exposed to the pain stimulus and work task. Half of the subjects were randomly chosen to perform the task with a low-intensity pain stimulus (LP) and the other half performed the task while exposed to a high-intensity pain stimulus (HP). The results indicated that subjects in the high-avoidant model conditions (HA) did significantly less work and tolerated the pain stimulus for significantly fewer seconds compared to the low-avoidant model groups (LA). Subjects in the LP groups tolerated the pain stimulus significantly longer and did significantly more work compared to subjects in the HP groups. No significant interaction was observed. The results provide support for the hypothesis that behavioral reactions to pain can be acquired by vicarious experience. Implications for future research are discussed.     

Effects of perceived similarity on vicarious emotional conditioning

The present experiment tested the hypothesis that perceived similarity between observers and models enhances vicarious emotional conditioning. Subjects were led to believe that they were either similar to the model in beliefs and attitudes, different from him or were given no information about him. They then underwent a vicarious classical conditioning procedure by witnessing the model express pain reactions in conjunction with a neutral stimulus. Observers developed emotional reactions to the neutral stimulus alone after seeing it paired with modeled pain expressions. Preceived similarity, however, had no significant effect on either the level of vicarious conditioning or the rate of extinction. Subjects who had no information concerning the model displayed stronger autonomic responses to the model's pain expressions, and more frequent and intense autonomic responses to the conditioned stimulus during tests for acquisition and extinction. In correlational analyses, subjects in the latter condition also yielded a significant positive relationship between self-reported arousal and vicarious emotional conditioning. The obtained findings were interpreted in terms of the emotion arousing properties of unfamiliarity.     

Studies in observational paired-associate learning: Informational,social, and individual difference variables

Four experiments examined the relative importance of informational (proportion of correct responses and kinds of errors emitted by a model), social (model competency, sex of model, video vs. audio taped model), and individual difference (sex of subject, grade) variables in observational paired-associate learning. In Experiments I–III, vicarious subjects received cycles of study-model-test trials, while direct subjects were given the same sequences with intervening test or stimulus familiarization trials. In Experiment IV, vicarious subjects received cycles of study-test-model-test trials, while direct subjects received the cycles with a test trial replacing the model trial. No confirmation was provided on test and model trials. Whereas the effects attributable to social and individual difference variables were generally negligible, mere accuracy of the model's responses repeatedly covaried with performance on the last test trial of each cycle. Conditional analyses established that (1) vicarious facilitation is comparable across cycles and localized in items responded to incorrectly on immediately preceding test trials, and (2) observers learn fewer incorrect than correct model responses. Vicarious groups performed at reliably higher levels than direct subjects on model correct but not incorrect items. The results strongly suggest a close correspondence between direct and vicarious verbal learning principles and mechanisms.     

Differentiation between vicarious instigation and classical conditioning of electrodermal responses

In past research of vicarious conditioning when a conditioned stimulus (CS) was repeatedly presented both to a model and an observer, the observer's reaction to the CS may have been the result of a vicariously conditioned reaction to the CS, as well as a vicariously instigated reaction to the inferred emotional state of the model who anticipates the reception of a noxious stimulus when the CS is presented. In order to partial out these two reactions, the present experiment employed 32 subjects of both sexes who took part in a two-group study of differential, vicarious classical conditioning of skin conductance responses. In one of the group, the tones serving as CS+ and CS- and which preceded the aversive and non aversive events to the mode, were presented over earphones to both the confederate model and the observer subject. In the second group, only the subjects had earphones on and were led to believe that the model was not aware of the CS presentations. This eliminated the possibility of vicariously instigated reactions. Although the conditioning effects produced in the present study were somewhat weak, results clearly showed equal levels of vicarious instigation and conditioning in the two groups. These results indicate that the potential confounding of these two reactions studies has not significantly affected result or conclusions from previous studies.     

The effect of modification of expressive displays on vicarious emotional arousal

Several recent experiments have demonstrated that modulation of the facial expressive response is accompanied by changes in autonomic arousal and subjective response to painful stimuli. The present study asked whether facial self-regulation may also bring about changes in covert vicarious emotional experience. Three groups of subjects were exposed to a videotaped model displaying intermittent pain to shock in a differential vicarious autonomic conditioning paradigm. Subjects in the inhibit and amplify groups were asked, respectively, (a) to inhibit their facial muscles or (b) to pose a facial response of pain when the model was shocked. It was predicted that the inhibit group would show less autonomic arousal to the model's expressive display (empathy) and less conditioning (as measured by skin conductance and heart rate change), and the amplify group more empathy and conditioning, than a third group who was given no facial instruction. In fact, the amplify group showed more skin conductance arousal, heart rate acceleration, and activity in response to the model's expressive display of pain than did the other two groups (which were not different from each other), but no more autonomic or facial conditioning. The overall pattern of physiological data is interpreted as generally supportive of a facial feedback theory of emotion: where significant between-groups' differences were obtained in facial activity, as in vicarious instigation, autonomic arousal differences also emerged; where no expressive differences were obtained, as in vicarious conditioning, no differences in autonomic arousal were found.     

What’s good for me depends on what I see in you: Intimacy avoidance and resources derived from close others

Past research has demonstrated that comfort with intimacy differentially affects the extent to which a person assimilates/contrasts to a close other. Specifically, individuals comfortable with intimacy benefit most from assimilating to those who embody positive aspects, whereas individuals uncomfortable with intimacy benefit most from contrasting to those who embody a mix of positive and negative aspects. Using a multi-method approach, the current research provides evidence suggesting that both those who are positively regarded and those who engender mixed feelings have the potential to benefit the perceiver differentially as a function of the types of traits that are most salient at the time. In Study 1, consistent with predictions, high-avoidant individuals contrasted to the salient traits of a romantic partner and performed better on an intelligence test after thinking about their partner’s unintelligent compared to intelligent traits, whereas low-avoidant individuals assimilated. In Study 2, high-avoidant individuals contrasted to friends’ traits and exhibited more positive cardiovascular responses (i.e., greater challenge) while talking about friends’ negative traits and more negative responses (i.e., greater threat) while talking about friends’ positive traits. Together, these findings suggest that there are situations during which low- and high-avoidant individuals differentially benefit from highly regarded close others.     

The development of selective inhibitory control: The influence of verbal labeling

The role of language in the development of selective inhibitory control was examined in four groups: Children aged 7-9 years, children aged 11-13 years, adults aged 20-27 years, and adults aged 62-76 years. We used a modified stop-signal task in which participants inhibited or executed responses based on a visual signal. Response execution and inhibition were assessed by measurement of reaction times (RTs) and error rates to a go signal and RTs to a stop signal. Four task variations were compared in which subjects named (1) the stimulus, (2) the intended action (go/stop), (3) something irrelevant, or (4) nothing. Results showed different developmental trends for response execution and inhibition across the lifespan. Moreover, response execution was faster and more accurate when subjects named the stimulus instead of the intended action. The increase in response accuracy when naming the stimulus was greatest for children. In contrast to expectations, naming the intended action did not influence response inhibition. Overall, these findings suggest that verbal labeling supports the initiation but not the inhibition of actions.     

Transient effects of acquisition history on generalization in a matching-to-sample task

This study examined the role of learning history on the acquisition of a matching-to-sample task. Twelve preschool children learned four stimulus classes through instructions, shaping, or imitation. After reaching criterion, the subjects were exposed to changed discrimination contingencies to determine how each learning history affected the acquisition of responses appropriate to the new contingencies. All subjects reached criterion on the new relations, although the subjects with a shaping history adapted slightly more quickly than those subjects with a history of instructions or imitation. Given sufficient exposure to changed contingencies, rule-driven insensitivity to contingencies was overcome by experience with consequences. This result may be specific to younger subjects, but it suggests that instructions can be used in education without creating insensitivity to contingencies.     

A connectionist modeling study of the neural mechanisms underlying pain’s ability to reorient attention

Connectionist modeling was used to investigate the brain mechanisms responsible for pain’s ability to shift attention away from another stimulus modality and toward itself. Different connectionist model architectures were used to simulate the different possible brain mechanisms underlying this attentional bias, where nodes in the model simulated the brain areas thought to mediate the attentional bias, and the connections between the nodes simulated the interactions between the brain areas. Mathematical optimization techniques were used to find the model parameters, such as connection strengths, that produced the best quantitative fits of reaction time and event-related potential data obtained in our previous work. Of the several architectures tested, two produced excellent quantitative fits of the experimental data. One involved an unexpected pain stimulus activating somatic threat detectors in the dorsal posterior insula. This threat detector activity was monitored by the medial prefrontal cortex, which in turn evoked a phasic response in the locus coeruleus. The locus coeruleus phasic response resulted in a facilitation of the cortical areas involved in decision and response processes time-locked to the painful stimulus. The second architecture involved the presence of pain causing an increase in general arousal. The increase in arousal was mediated by locus coeruleus tonic activity, which facilitated responses in the cortical areas mediating the sensory, decision, and response processes involved in the task. These two neural network architectures generated competing predictions that can be tested in future studies.     

Cognitive style and recognition memory in young adults

Differences between impulsive and reflective subjects may be related to the amount of information processed in a given task. This possibility was tested in a visual-verbal probe recognition task. Twenty-three impulsive and 23 reflective adults subjects were divided into experimental and control groups. Experimental subjects were briefly exposed to a complex stimulus, whereas control subjects were given a comparable exposure to a different stimulus. Subjects were asked to choose between equal number of positives (stimulus-relevant) and negative probe items. A comparison of areas under memory operating characteristic curves for experimental subjects indicated that the recognition threshold for positive probes for impulsive subjects was significantly lower than the threshold for reflective subjects. The difference between subjective likelihood criteria was not significant. Also, accuracy of experimental subjects was significantly greater than that of control subjects. Differences in information availability were thought to be indicative of differences in selective attention processes.     

Visual encoding of patterns is subject to dual-task interference

Two stimuli were presented at varying stimulus onset asynchronies (SOAs), with each stimulus associated with a distinct task. The first stimulus was a tone at one of either two or three frequencies. In two conditions, the task associated with a tone was either a speeded two-alternative discrimination (2AD), or a speeded three-alternative discrimination (3AD) based on the pitch of the tone. In a third condition, subjects were told to ignore the tone. The second stimulus was a briefly exposed study matrix of red and black squares followed by a mask. After a fixed delay, the mask was replaced by a test matrix that was either the same or different from the study matrix. The task associated with the matrices was to indicate, with no speed pressure, whether the study matrix and the test matrix were the same or different. Results from each speeded AD condition showed that subject's accuracy in the matrix task decreased as the SOA between the tone and the study matrix decreased. This effect was larger for the 3AD tone task than with a 2AD tone task. In addition, within each speeded AD condition, longer RTs in the tone task were associated with lower accuracy in the matrix task. None of these effects was evident when the subjects were told to ignore the tone. These results suggest that encoding visual information can be subject to significant capacity limitations imposed by cross-modal multitasking.     

Effects of differentially modeled stimuli on vicarious autonomic arousal

The present study examined effects of variations in modeled pain cues on level of vicarious arousal, using heart rate and blood-volume amplitude as psychophysiological measures. Students were assigned randomly to one of four groups in which they either (a) underwent directly the cold-pressor test, (b) observed a model exposed to the cold-pressor test and expressing pain by facial and bodily movements, (c) heard only the modeled verbal expressions of pain, or (4) observed the model express neither verbal expressions nor physical movements while undergoing the painful stimulation. The results show aversive stimulation increases heart rate whereas vicarious aversive stimulation produces reductions in heart rate. The deceleration of heart rate was not found in response to all three forms of modeling. Both direct and vicarious aversive stimulation produced decreases in the amplitude of vasomotor responses. The size of the decrement between direct stimulation and the minimal modeling condition of vicarious arousal showed significant differences, but differences between direct stimulation and the maximal modeling condition were not significant. The vasoconstriction was found in response to two forms of modeling.     

金钱奖赏对海洛因戒断者工作记忆刷新功能的促进作用减弱

采用有无金钱奖赏条件下的n-back任务，探讨金钱奖赏对海洛因戒断者工作记忆刷新功能的影响。结果发现：所有被试在金钱奖赏条件下的反应时都显著短于无奖赏条件下的反应时；海洛因戒断组在有无金钱奖赏条件下的反应时的差值显著小于正常组在有无金钱奖赏条件下的反应时的差值；在1-back和2-back任务中，正常组的正确率显著高于海洛因戒断组的正确率。结果表明：金钱奖赏对海洛因戒断者工作记忆刷新功能存在一定的促进作用，但是其促进作用幅度要弱于正常人；海洛因戒断者的工作记忆刷新功能可能存在损伤。     

The disruptive nature of pain: An experimental investigation

Pain interrupts, distracts and takes effort to ignore. Focusing our research attention upon this central aspect of pain experience, an experimental paradigm is introduced to study the disruptive nature of pain. Healthy volunteers were exposed several times to an electrical pain stimulus and a control stimulus. Tone probes were presented immediately (100 ms) and later on (1500 ms) after pain/control onset, and after pain/control offset (1000 ms). Results clearly showed disruption during pain. This disruptive effect was most marked immediately after onset. No differential results between pain and control conditions were observed later on during the pain experience. These results are interpreted within current cognitive and psychophysiological theories of attention. Emphasis is placed upon the importance of the experimental investigation of the role of attention in pain processing.     

Learning to fear a second-order stimulus following vicarious learning

Vicarious fear learning refers to the acquisition of fear via observation of the fearful responses of others. The present study aims to extend current knowledge by exploring whether second-order vicarious fear learning can be demonstrated in children. That is, whether vicariously learnt fear responses for one stimulus can be elicited in a second stimulus associated with that initial stimulus. Results demonstrated that children's (5–11 years) fear responses for marsupials and caterpillars increased when they were seen with fearful faces compared to no faces. Additionally, the results indicated a second-order effect in which fear-related learning occurred for other animals seen together with the fear-paired animal, even though the animals were never observed with fearful faces themselves. Overall, the findings indicate that for children in this age group vicariously learnt fear-related responses for one stimulus can subsequently be observed for a second stimulus without it being experienced in a fear-related vicarious learning event. These findings may help to explain why some individuals do not recall involvement of a traumatic learning episode in the development of their fear of a specific stimulus.     

Interactive and vicarious acquisition of auditory preferences in Northern bobwhite (Colinus virginianus) chicks

Studies examining the effects of stimulus contingency on filial imprinting have produced inconsistent findings. In the current study, day-old bobwhite chicks (Colinus virginianus) received individual 5-min sessions in which they were provided contingent, noncontingent, or vicarious exposure to a variant of a bobwhite maternal assembly call. Chicks given contingent exposure to the call showed a significant preference for the familiar call 24 hr following exposure and significantly greater preferences than chicks given noncontingent exposure. Chicks given vicarious exposure to recordings of another chick interacting with the maternal call showed significant deviations from chance responding; however, the direction of chick preference (toward the familiar or unfamiliar) depended on the particular call used. These results indicate that both direct and indirect (vicarious) exposure to stimulus contingency can enhance the acquisition of auditory preferences in precocial avian hatchlings. Precocial avian hatchlings thus likely play a more active role in directing their own perceptual and behavioral development than has typically been thought.     

Observational learning of two visual discriminations by pigeons: a within-subjects design.

Pigeon's observational learning of successive visual discrimination was studied using within-subject comparisons of data from three experimental conditions. Two pairs of discriminative stimuli were used; each bird was exposed to two of the three experimental conditions, with different pairs of stimuli used in a given bird's two conditions. In one condition, observers were exposed to visual discriminative stimuli only. In a second condition, subjects were exposed to a randomly alternating sequence of two stimuli where the one that would subsequently be used as S+ was paired with the operation of the grain magazine. In a third experimental condition, subjects were exposed to the performance of a conspecific in the operant discrimination procedure. After exposures to conspecific performances, there was facilitation of discriminative learning, relative to that which followed exposures to stimulus and reinforcement sequences or exposures to stimulus sequences alone. Exposure to stimulus and food-delivery sequences enhanced performance relative to exposure to stimulus sequences alone. The differential effects of these three types of exposure were not attributable to order effects or to task difficulty; rather, they clearly were due to the type of exposure.     

Choice As A Function Of Reinforcement Ratios In Delayed Matching-to-sample

Pigeons were studied in two experiments using a delayed matching-to-sample task. In Experiment 1, 4 subjects were exposed to a task in which the proportion of reinforcement associated with matching and nonmatching, and the overall proportion of reinforcement associated with selecting each choice, regardless of the sample stimulus, were varied. Choice was sensitive to both proportions. A least squares regression analysis showed that Wixted's (1989) proportions of reinforcement model closely fit the data from Experiment 1; however, the model failed to make accurate qualitative predictions for some test conditions. In Experiment 2, 4 subjects were exposed to a delayed matching-to-sample task in which the retention intervals and the reduction in delay to reinforcement signaled by the onset of the sample stimulus were independently varied. When the retention interval was short and when the delay-reduction value of the sample stimulus was high, the sample exerted greater control over choice; the control by the overall proportion of reinforcements for selecting each choice stimulus was correspondingly low. Conversely, when the retention interval was long and the delay-reduction value of the sample stimulus was low, the sample exerted relatively less control over choice; control by the overall proportion of reinforcements obtained for selecting each choice stimulus was correspondingly high. A signal detection analysis found that sensitivity to reinforcement varied directly with retention interval. Data were also consistent with misallocation models. No evidence was found to suggest that pigeons ignore the rate at which selecting individual choice stimuli is reinforced, as has been reported in studies with human subjects.     

Locus of control and cerebral asymmetry.

Data about the lack of synchronism of flexor carpi ulnaris peak EMG values of bimanual reactions during a semantic and during a visuospatial discrimination reaction time task are reported. The effects of type of task as well as the presence or absence of an unexpected stimulus preceding the reaction stimulus on lack of synchronism clearly depend upon the locus of control of the subjects, as measured on Rotter's I-E scale. On the basis of several arguments it is proposed that the measure of lack of synchronism reflects in an opposite sense the amount of dopaminergic activation or motor readiness in the sense in which Pribram and McGuinness in 1975 and Tucker and Williamson in 1984 have defined these concepts. The results for 15 women and 18 men show that more internally oriented subjects are more activated by a semantic task and by an unexpected preparatory stimulus in this type of task than more externally oriented subjects. The opposite appears to hold on the visuospatial task and unexpected preparatory stimuli therein. Together with earlier findings about reaction times and a number of relevant findings in the literature, the results are interpreted as indicative of basic differences in asymmetric tonic activation of the cerebral hemispheres between more internally and more externally oriented subjects. A model is proposed to explain phasic activating effects which ensue when tonically more left- or right-activated subjects perform left- or right-hemisphere tasks and when supplementary irrelevant stimuli are received.     

Endogenous-like orienting of visual attention in rats

This study investigated the orienting of visual attention in rats using a 3-hole nose-poke task analogous to Posner, Information processing in cognition: the Loyola Symposium, Erlbaum, Hillsdale, (1980) covert attention task for humans. The effects of non-predictive (50% valid and 50% invalid) and predictive (80% valid and 20% invalid) peripheral visual cues on reaction times and response accuracy to a target stimulus, using Stimuli-Onset Asynchronies (SOAs) varying between 200 and 1,200 ms, were investigated. The results showed shorter reaction times in valid trials relative to invalid trials for both subjects trained in the non-predictive and predictive conditions, particularly when the SOAs were 200 and 400 ms. However, the magnitude of this validity effect was significantly greater for subjects exposed to predictive cues, when the SOA was 800 ms. Subjects exposed to invalid predictive cues exhibited an increase in omission errors relative to subjects exposed to invalid non-predictive cues. In contrast, valid cues reduced the proportion of omission errors for subjects trained in the predictive condition relative to subjects trained in the non-predictive condition. These results are congruent with those usually reported for humans and indicate that, in addition to the exogenous capture of attention promoted by both predictive and non-predictive peripheral cues, rats exposed to predictive cues engaged an additional slower process equivalent to human's endogenous orienting of attention. To our knowledge, this is the first demonstration of an endogenous-like process of covert orienting of visual attention in rats.