Alcohol and unpleasant stimulation: subjective shock calibration and pain and discomfort perception

In an experiment 8 men participated in an alcohol and a sober condition in a rotated order. In both conditions subjects first calibrated a shock scale to a subjective criterion and then rated their subjective pain and total discomfort. Subjects calibrated the shock scale higher when intoxicated and rated the calibrated level equally painful in the sober and intoxicated conditions, but when intoxicated subjects actually rated the higher shock level as less uncomfortable. The shock scale was calibrated higher under intoxication not because subjects wanted to impress the experimenter but because less pain and discomfort was actually experienced.     

Effects of nonverbal dissimulation on emotional experience and autonomic arousal.

Three studies are reported that examine the relationship between the nonverbal display of emotional affect and indices of the emotional state. Subjects were asked either to conceal or to exaggerate the facial display associated with the anticipation and reception of painful shocks that varied in intensity. Both self-reports of shock painfulness and skin conductance measures of emotional response showed significant changes paralleling the changes induced in expressive behavior; that is, the suppression of expressive responses decreased the magnitude of phasic skin conductance changes and subjective reports of painfulness as compared to the free expression or exaggeration of pain-related expressive response. The effects were obtained for shocks of varying intensities and for both male and female subjects. The findings support theories of emotion that assume that expressive responses serve a self-regulatory as well as a social-communicative function, and further suggest that the self-regulation is mediated neurally, rather than via a process of self-attribution. Finally, the results highlight the need for research on dissimulation in social interaction to consider the effects of acting upon the actor, as well as its effects upon the inferences of observers.     

Integration of noxious stimulation across separate somatosensory communications systems: a functional theory of pain

Functional measurement analyses and psychophysical techniques were used to assess how separate, cross-modal, aversive events are integrated in judgements of pain. Subjects made magnitude estimations of noxious stimuli produced by a 6 X 6 factorial design of electric shocks and loud tones. Group data and most of the individual results were consistent with a model of linear pain summation: The estimates of pain approximated the linear sum of the pain estimates of the individual electrocutaneous and auditory components. The relation between painful sensation and current intensity could be described by a mildly expansive power function with an exponent of about 1.1. Auditorily produced painful sensation related to sound pressure level by a mildly compressive power function with an exponent of about 0.90 as a representative figure. Results are interpreted in terms of a functional theory of pain. Noxious events are first transformed to psychological scale values via stimulus-specific psychophysical transfer functions. The outputs of these functions are then combined with other pain-related internal representations of either sensory or cognitive origin, according to simple algebraic models.     

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.     

Judgments of genuine, suppressed, and faked facial expressions of pain.

The process of discriminating among genuine, suppressed, and faked expressions of pain was examined. Untrained judges estimated the severity of pain being experienced when viewing videotaped facial expressions of chronic pain patients undergoing a painful diagnostic test or dissimulating reactions. Verbal feedback as to whether pain was experienced also was provided, so as to be either consistent or inconsistent with the facial expression. Judges were able to distinguish genuine pain faces from baseline expressions but, relative to genuine pain faces, attributed more pain to faked faces and less pain to suppressed ones. Advance warning of deception did not improve discrimination but led to a more conservative or nonempathic judging style. Verbal feedback increased or decreased judgments, as appropriate, but facial information consistently was assigned greater weight. An augmenting model of the judgment process that attaches considerable importance to the context in which information is provided was supported.     

Acceptance versus distraction: brief instructions, metaphors and exercises in increasing tolerance for self-delivered electric shocks

The current study compared the effects of an acceptance versus distraction rationale on coping with experimentally induced pain. Eighty participants were randomly assigned to one of five conditions: Full-Acceptance, Full-Distraction, Instruction-only-Acceptance, Instruction-only-Distraction and No-Instructions. Participants completed a simple matching task and were intermittently given the choice either to receive an electric shock and continue, or to avoid the shock and terminate the task. Only the Full-Acceptance strategy (that included experiential exercises and a metaphor) had a significant effect on task tolerance as measured by an increase in the number of shocks delivered post-intervention relative to baseline. In addition, the participants in both of the acceptance conditions showed lower levels of believability in that they were more likely to continue with the task even when reporting more pain. The results support the prediction that acceptance-based interventions work by undermining the behavioural-control functions of pain-related thoughts and feelings, and call for a systematic analysis of how metaphors and exercises work in analogue research.     

The time course of learned helplessness, inactivity, and nociceptive deficits in rats

Four experiments are reported which explore the nature of the effects of inescapable shock on subsequent shuttlebox escape learning. The first experiment demonstrated that shuttle escape deficits dissipate within 48 hr after treatment with inescapable shock. Experiment 2 showed that exposure to inescapable shock suppressed unlearned activity in the shuttlebox and that this activity deficit recovered within 48 hr. Experiment 2A demonstrated that this shuttlebox crossing decrement was at least partly attributable to the inescapability of the shocks. These results suggested that activity factors might partly mediate the shuttle escape learning deficit reported in Experiment 1. Experiment 3 explored the possibility that activity and shuttle escape learning deficits are subserved by the effects of inescapable shock on pain sensitivity. The results supported this notion. It was found that rats were less sensitive to painful stimulation 24 hr after inescapable shock and that this analgesic tendency also dissipated within 48 hr after pretreatment. The implications of these results were discussed.     

Pain combines additively across different sensory systems: a further support for the functional theory of pain

Subjects made magnitude estimations of noxious stimuli produced by a 6 X 6 factorial design of electric shocks (pulse trains) and loud tones. Group data and all individual results conformed to a linear additive model of pain. The estimates of pain approximated the linear sum of the pain estimates of the individual electrocutaneous and auditory components. Pain related differently to the two inducing stimuli. It grew as a mildly expansive power function of current intensity (with an exponent of about 1.2) but as a mildly compressive power function of sound-pressure level (with an exponent of about 0.8). These results replicate recent findings by the same authors in 1986 using a more aversive type of electric stimulation. They are interpreted as supportive of a new functional approach to understand pain and pain-related phenomena.     

The role of regression and range effects in determination of the power function for electric shock

A scale for the apparent intensity of electric shock applied to the forearm was derived from cross-modality matching functions relating noise level, number, and force of handgrip to both line length and shock. For each response mode, the effects of psychophysical regression were estimated from the line judgments and used to make adjustments in the corresponding shock judgments. For shocks ranging from (1.0 to 5.5 mA, combined estimates of subjective magnitude were found to grow as the 2.26 power of the stimulating current.     

The formalin test and the opioid nature of stress-induced analgesia

Exposure to electric shock produces an analgesic reaction (SIA) that is reversed by opiate antagonists ("opioid" SIA) under some conditions but not under other conditions ("nonopioid" SIA). A number of studies using tail-flick to radiant heat as the measure of pain sensitivity have found that a small number of shocks lead to nonopioid SIA, while a large number of shocks produce opioid SIA. In contrast, a small number of shocks have been reported to produce opioid SIA when the Formalin test was used to measure pain reactivity. However, the Formalin test involves administering a chronic pain stimulus (injection of Formalin into the paw) for an extended period before the shocks. Here it is reported that this "preexperimental" stress is sufficient to convert the SIA after a small number of shocks measured by tail-flick to the opioid form.     

Biting attack by rats in response to aversive shock

Paired rats are known to behave aggressively when given painful electric shocks. The present study developed a procedure whereby individual rats given shocks might bite an inanimate target object. Unavoidable shock was delivered to the rat while it was restrained in a position close to, and facing a target object. Biting of the target was recorded automatically. Shock caused the rat to bite metal, wood, or rubber targets. Biting was most frequent immediately after shock and decreased as a direct function of time since the shock. Almost every shock produced biting and the behavior continued as long as the shocks were delivered. Biting ceased within and between sessions when shocks were discontinued. These results show how the pain-aggression relation can be studied objectively with rats.     

Deliberate Self-Harm and State Dissociation: An Experimental Investigation

The purpose of this study was to test the relation between deliberate self-harm (DSH) and state dissociation. Participants (N = 85) were randomly assigned to self-administer either a very mild electric shock below their pain threshold (a no-self-harm control condition) or an electric shock they were told could “cause minor tissue damage that would heal quickly,” but which was in fact equal to a predetermined pain threshold (a DSH condition). After task completion, 42 participants rated the extent of their dissociation before the shock and 43 rated the extent of their dissociation after the shock. Results indicated that women in the DSH group experienced more dissociation compared to men, but only after the shock. Potential reasons for this gender effect are discussed.     

Effects of uncertainty,delay, and focus of attention on reactions to an aversive situation

The hypotheses of informational cognitive control, based on the idea that being able to predict the occurrence of an unpleasant event facilitates a reduction of its impact, has not received clear support in previous research. The present experiment investigated the effects of three variables on subjective reactions to mild electric shock: (1) temporal uncertainty about when the shocks would occur, (2) the period of delay before the shock, and (3) attention to either the sensory properties of the shocks or emotional reactions to them. The results showed that low temporal uncertainty and short periods of delay led to reduced anxiety during the period preceding the shock but did not reduce the reported intensity of the shocks themselves. Higher ratings of both shock intensity and distress were obtained when the focus of attention was on the sensory properties of the stimuli rather than on the affective reactions to them. It was concluded that (i) the attentional focus of the subject is an important determinant of rated stimulus effects, and (ii) prediction, though it may reduce prestimulus anxiety, has no real effect on the impact of the stimulus itself.     

The observer's acquaintance with the model's stimulus in vicarious classical conditioning

To disentangle possibel mediating mechanisms in vicarious learning, the observer's acquaintance with an annoying stimulus was varied before taking part in a classical conditioning procedure where the model ostensible received strong electric shocks. For a total 64 observers of both sexes the pre-conditioning acquaintance was varied in a 2times2 factorial design with Intensity (strong/week) and Modality (shock/tone) as independent variables. In the differential long interstimulus interval conditioning procedure, skin conductance responses (SCRs) were employed as the main dependent measure, and were supplemented by post-experimental questionnaire ratings. Data analyses indicated that the observers with a weak intensity of pre-experimental acquaintance conditioned SCRs better than those with a strong intensity, which was contrary to hypotheses. For the post-experimental ratings no such effect was indicated. The results are discussed in terms of the observer's perceived self-suffering to the model's stimulus and the intensity of the model's emotional state as perceived by the observer. It is argued that the groups with a strong intensity of pre-experimental discomfort preceived the model's emotional state as less intense than the groups who had encountered a weak intensity stimulus.     

Naloxone and shock-elicited freezing in the rat.

The freezing behavior of the rat that occurs following painful electric shock was found to increase when the animal was pretreated with the opiate antagonist naloxone. Freezing was a positive linear function of drug dose and shock intensity (Experiment 2). Naloxone pretreatment enhanced freezing only when the animal was given two or three shocks but did not affect freezing when the animal was given only one shock or not shocked at all (Experiments 3, 4, and 5). Naloxone must be present during shock, nor just during the observation period, in order to increase freezing (Experiment 6). These results suggest that when an animal is shocked, it releases endogenous analgesics (endorphins) that make a subsequent shock less aversive. Naloxone, by blocking the endorphin system, makes the shock more aversive than it would normally be.     

Effects of a stimulus associated with a victim's pain on later aggression.

Male college students participated in an experiment designed to associate a neutral stimulus with a victim's pain and then to assess the impact of the paired stimulus on their aggression. The subjects were either provoked or not provoked by a confederate's shock evaluation. They then observed a flashing white light that was associated with either their former evaluator's pain or an irrelevant, affectively neutral event. The subjects then administered electric shocks to a different confederate, with whom they had not interacted previously, at the flash of both the familiar white light (the conditioned stimulus) and a novel blue light. Results supported the prediction that provoked subjects would give more intense shocks to the conditioned stimulus when it had been associated with their evaluator's pain. Unprovoked subjects were found to give less intense shocks to the light that had been associated with their evaluator's pain.     

Threat of pain influences social context effects on verbal pain report and facial expression

Current theoretical models of pain catastrophizing have diverging predictions regarding the role of social context and perceived threat on pain expression. The communal coping model of catastrophizing predicts that high pain catastrophizers display more pain expression in the presence of another, regardless of the threat value of the pain, while a cognitive appraisal model predicts high pain catastrophizers to express more pain when pain has increased threat value, regardless of social context. A 2 × 2 factorial design was used to test the validity of both predictions. Healthy participants with varying levels of pain catastrophizing were exposed to a cold pressor task, consisting of a 60 s immersion and 60 s recovery period. Interestingly, the immersion results revealed that beyond and independent from the effects of pain catastrophizing, the effect of threat on verbal pain report and facial expression was dependent on social context and vice versa. In a threatening context, perceived threat of pain mediated the inhibitory effect of social presence on pain expression, suggesting that the observer acted as a safety signal. In the recovery period, social presence enhanced facial expression, but only when no threat was induced. The results are discussed in terms of the dynamic interaction between social context and threat appraisals.     

From personal goals disclosed to personality judgments composed: Trait perceptions made on the basis of idiographic goals

Traits and goals represent discrete units of personality. Here, we examined the consensus, validity, and cues of trait judgments made on the basis of targets’ goals. Targets (N = 409) generated lists of personal goals and rated their traits. Observers were provided with targets’ (a) lists of goals, (b) first goals, or (c) fifth goals, and then reported trait judgments of targets. Perceptions of targets, which were formed on the basis of the emotional content of goals, were largely consistent among observers. Furthermore, observer reports made on the basis of participants’ lists of goals converged with self-reports of all traits whereas reports made on the basis of single goals converged with self-reports of certain (e.g., extraversion), but not all, traits.     

Observing emotion in infants: facial expression,body behavior,and rater judgments of responses to an expectancy-violating event

Eleven-month-old European-American, Japanese, and Chinese infants (ns = 23, 21, and 15, respectively) were videotaped during baseline and stimulus episodes of a covert toy-switch procedure. Infants looked longer at the object during the expectancy-violating event (stimulus episode) but did not produce more surprise-related facial expressions. American and Japanese infants produced more bodily stilling during stimulus than baseline, and American infants also produced more facial sobering. Naive raters viewing both episodes could correctly identify the expectancy-violating event. Rater judgments of surprise were significantly related to infants' bodily stilling and facial sobering. Judgments of interest were related to cessation of fussing. Thus, observer judgments of infant emotions can be systematically related to behaviors other than prototypic emotional facial expressions.