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.     

Contextual Fear after Signalled versus Unsignalled Shocks: Effect of Extent of Prior Experience with Context and Signal

In the first two experiments, rats were differentially familiarized with a discrete stimulus and/ or a context prior to receiving either shocks signalled by that stimulus or unsignalled shocks in that context. As indexed by freezing, in none of the pre-exposure conditions did the signalled-shock rats consistently acquire less contextual fear than the unsignalled-shock animals. Both pre-exposure to the stimulus and relatively short pre-exposure to the future conditioning context resulted in more contextual fear in the signalled-shock than in the unsignalled-shock subjects. In a third experiment, freezing in the target conditioning context was especially enhanced in rats that had been familiarized with a stimulus, conditioned with the stimulus as a signal for shock, and subsequently further conditioned to the stimulus in a different, non-target context. The level of freezing to the stimulus in a neutral test context was positively related to the level of freezing in the target conditioning context in all experiments. These results were discussed in terms of context-shock, stimulus-shock, and context-stimulus associations.     

Inhibitory conditioning resulting from a reduction in the magnitude of reinforcement

Five experiments, all employing conditioned suppression in rats, studied inhibitory conditioning to a stimulus signalling a reduction in shock intensity. Experimental subjects were conditioned to a tone signalling a 1·0 mA shock and to a tone-light compound signalling a 0·4 mA shock. On a summation test in which it alleviated the suppression maintained by a third stimulus also associated with the 1·0 mA shock, the light was established as a conditioned inhibitor. Retardation tests gave ambiguous results: the light was relatively slow to condition when paired, either alone or in conjunction with another stimulus, with the 0·4 mA shock, but the difference from a novel stimulus control group was not significant. Two final experiments found no evidence at all of inhibition on a summation test in which the light was presented in conjunction with a stimulus that had itself been associated with the 0·4 mA shock. The results of these experiments have implications for the question of what animals learn during the course of inhibitory conditioning.     

Conditioned changes in pain reactivity I: A discrete CS elicits hypoalgesia, not hyperalgesia, on the tail-flick test

Prior work suggests that a stimulus which has been paired with an aversive event may elicit either an increase or decrease in pain reactivity. In four experiments we attempted to isolate the variables which determine the direction of the conditioned response. In all experiments, one stimulus was paired with shock (the CS+) while another was nonreinforced (the CS−). Pain reactivity was assessed by measuring tail withdrawal from radiant heat (the tail-flick test). Experiment 1 tested whether the amount of training plays a critical role. We found that the CS+ elicits longer tail-flick latencies irrespective of whether subjects received 6 or 24 CS-US pairings. Although there was some evidence that subjects may exhibit a general hyperalgesia at 2 min after the presentation of the conditioned stimulus, the results of Experiment 2 revealed that this effect was an artifact caused by differences in the amount of time between test trials. The results of Experiment 2 also showed that the difference observed between the CS+ and CS− was not due to a CS− induced hyperalgesia. Rather, it reflects a CS+ induced hypoalgesia. Experiment 3 evaluated whether the time of day at which testing occurs is important. We found that subjects exhibit conditioned hypoalgesia when tested in either the light or dark portion of the light-dark cycle. In Experiment 4 we examined whether it matters if subjects are tested in the training context or a neutral context. We found that subjects exhibit conditioned hypoalgesia during the CS+ irrespective of where they are tested. The results suggest that a CS+ elicits hypoalgesia, not hyperalgesia, on the tail-flick test over a wide range of conditions.     

The Effect of Counterconditioning on Evaluative Responses and Harm Expectancy in a Fear Conditioning Paradigm

In fear conditioning, extinction targets harm expectancy as well as the fear response, but it often fails to eradicate the negative affective value that is associated with the conditioned stimulus. In the present study, we examined whether counterconditioning can serve to reduce evaluative responses within fear conditioning. The sample consisted of 70 nonselected students, 12 of whom were men. All participants received acquisition with human face stimuli as the conditioned stimuli and an unpleasant white noise as the unconditioned stimulus. After acquisition, one third of the sample was allocated to an extinction procedure. The other participants received counterconditioning with either a neutral stimulus (neutral tone) or a positive stimulus (baby laugh). Results showed that counterconditioning (with both neutral and positive stimuli), in contrast to extinction, successfully reduced evaluative responses. This effect was found on an indirect measure (affective priming task), but not on self-report. Counterconditioning with a positive stimulus also tended to enhance the reduction of conditioned skin conductance reactivity. The present data suggest that counterconditioning procedures might be a promising approach in diminishing evaluative learning and even expectancy learning in the context of fear conditioning.     

Power imbalance,its legitimacy,and aggression

Sixty Japanese female students were asked to exchange shocks in electric roulette games with female opponents. The subjects were assigned to either the 80%, 50%, or 20% win conditions. Half of them were then led to judge that the power unbalance was legitimate by being informed that the assignment was based on a prior performance contest, with the good performer being assigned to the advantageous position. The other subjects were led to perceive the power imbalance as illegitimate by being informed that the assignment was randomly decided. The opponents always severely attacked them. The retaliation by the subjects was analyzed by a two-way ANOVA with Power Imbalance and Legitimacy. It was found that the subjects both in the 20% and 50% win conditions set more intense shocks to their opponents than those in the 80% win condition. This is not consistent with the fear of retaliation hypothesis which had predicted that the subjects would refrain from intensely aggressing against the opponent who had a greater aggressive capacity. It was also found that in the 80% win condition, the subjects set more intense shocks when the unbalance had been determined by their performance than when determined by luck, whereas in the 20% win condition, they set more intense shocks when the imbalance had been determined by luck than when determined by their performance. These suggest that retaliation depended upon perceived justifiability of aggression which was predicated on the legitimacy of the power imbalance. Finding in the 50% win condition that the shock settings were higher when the power imbalance had been determined by their performance than when determined by luck was interpreted in terms of their heightened competitiveness.     

One-trial conditioned suppression: effects of instructions on extinction

Two experimental groups of undergraduate volunteers received a single Pavlovian conditioning trial consisting of a paired presentation of a tone conditioned stimulus (CS) and a shock unconditioned stimulus (UCS). Control groups received either the CS alone or the UCS alone. Subjects from one experimental group were subsequently instructed that they would not receive further shocks, while the other experimental group received no such instructions. The CS alone was then presented once to all four groups while subjects were engaged in a button-pressing task maintained by slide reinforcement. During the latter phase, rate of button-pressing was measured. Classically conditioned suppression of button-pressing was obtained in the noninstructed experimental group but not in the instructed group. The results demonstrate that suppression can be a sensitive index of Pavlovian conditioning in humans but question the use of conditioned suppression as an adequate experimental analog of clinically observed anxiety-motivated behavior.     

Effects of attack and uncontrollable noise on aggression

After being either attacked or treated in a more neutral manner by an experimental confederate, male subjects shocked the confederate while being stimulated by loud noise. Among previously attacked subjects, possession of control over offset of the noise led to the delivery of shocks significantly shorter in duration than those given by subjects who did not have control. Mere predictability of noise offset did not have the same effect. Subjects who could control the noise did not differ from those who heard no noise with respect to the duration of shocks given. Noise had no effect on shock duration among nonattacked subjects. In a follow-up study subjects who were given bogus information that they were aroused by noise were less punitive toward an attacking confederate than subjects given no such information. The overall conclusion is that noise facilitates aggression in subjects who have been instigated to aggress to the degree that noise-produced arousal is misattributed to the instigating stimulus.     

Dynamics of hostile aggression: Influence of anger,hurt instructions,and victim pain feedback

The research basically examined some of the dynamics of hostile aggression by looking at the effects of different Buss procedure instructions and levels of victim pain feedback on the aggressive behavior of angered and nonangered men. In a 2 × 2 × 2 completely crossed factorial experiment, male undergraduates were initially either angered or not by an experimental accomplice. When later given the ostensible opportunity to administer shocks to the same accomplice in a typical Buss procedure, the subjects were either told that longer and more intense shocks would probably interfere with the person's learning as well as causing him more pain (hurt instructions) or given no information about the effects of shocks on learning (standard instructions). Finally, after each shock they administered, the subjects were provided with either high or low victim pain feedback. The angered men were significantly more aggressive than their nonangered counterparts, and a significant interaction between anger and instructions indicated this was especially true for the men given hurt instructions. Significant interactions between the other independent variables and trial blocks revealed that the angered men, particularly those receiving hurt instructions and high victim pain feedback, displayed the greates increases in aggression. The results provide qualified support for the derived proposition about hostile aggression that signs and/or knowledge of victim injury and pain can stimulate more intense aggression from angry individuals.     

The fear potentiated startle effect. Blink reflex modulation as a result of classical aversive conditioning

A differential conditioning study examined whether an acoustic startle probe, presented during extinction of an aversively conditioned visual stimulus, potentiated the reflex eyeblink response in humans and whether this potentiation varied with the change in affective valence of the conditioned stimulus. Sixty college students were randomly assigned to view a series of two slides, depicting either unpleasant/highly arousing, unpleasant/moderate arousing, neutral/calm, pleasant/moderate arousing or pleasant/highly arousing scenes and objects (duration: 8 sec). During preconditioning (8 trials) and extinction (24 trials) acoustic startle probes (white noise bursts [50 ms; 95 dBA] were administered during and between slide presentation). During acquisition (16 trials) CS+ was reinforced by an electric shock. Startle response magnitudes significantly increased from preconditioning to extinction and were substantially larger to CS+. Conditioned startle reflex augmentation linearly increased with the pleasantness of the slides. Furthermore, subjects showed a greater post-conditioning increase of judged aversiveness to slides that they had previously reported to be more pleasant, exactly paralleling the startle reflex results.     

Nicotine trained as a negative feature passes the retardation-of-acquisition and summation tests of a conditioned inhibitor

Nicotine functions as a negative feature in a Pavlovian discriminated goal-tracking task. Whether withholding of responding to the conditional stimulus (CS) reflects nicotine functioning as a conditioned inhibitor is unknown. Accordingly, the present research sought to determine whether nicotine trained as a negative feature passed the retardation-of-acquisition and summation tests, thus characterizing it as a pharmacological (interoceptive) conditioned inhibitor. In the retardation test, rats received either nicotine (0.4 mg/kg) or chlordiazepoxide (5 mg/kg) negative feature training in which the drug state signaled when a 15-sec light CS would not be paired with sucrose; light was paired with sucrose on intermixed saline sessions. Following acquisition of the discrimination, both groups received nicotine CS training in which sucrose was intermittently available on nicotine but not intermixed saline sessions. Acquisition of conditioned responding to the nicotine CS was slower in the nicotine negative feature group than in the chlordiazepoxide negative feature group. In the summation test, rats were assigned to either the nicotine negative feature group or a pseudoconditioning control. In this control, the light CS was paired with sucrose on half the nicotine and half the saline sessions. Both groups also received excitatory training in which a white noise CS was paired with sucrose. The summation test consisted of presenting the white noise in conjunction with nicotine. Conditioned responding evoked by the white noise was decreased in the negative feature but not the pseudoconditioning group. Combined, the results provide the first evidence that an interoceptive stimulus (nicotine) can become a conditioned inhibitor.     

Status of the provoker,opportunity to retaliate,and interest in video violence

Two hypotheses derived from affect-dependent stimulus arrangement theory [Zillmann D, Bryant J (1985): In: “Selective Exposure to Communication.” Hillsdale, NJ: Erlbaum Associates.] were tested: (1) provoked persons will express less interest in seeing video violence than will those not provoked, unless they anticipate an opportunity to retaliate against their provocateur; and (2) when provoked persons anticipate an opportunity to retaliate against a provocateur who is not high status, they will express greater interest in seeing video violence than will those not provoked. After being provoked or not provoked by a high or low status experimenter, half the 160 male college student participants were led to believe that their evaluation of the experimenter would determine the experimenter's grade for conducting the research, and half were not given any reason to expect an opportunity to evaluate him. Then each man indicated his degree of interest in seeing each of twelve video selections that had been described in brief paragraphs, three each in four content categories: aggressive, humorous, mildly erotic, and neutral. In confirmation of the first hypothesis, provoked subjects who did not anticipate opportunity to retaliate expressed less interest in seeing aggressive material than did those not provoked. In relationship to the second hypothesis, provoked subjects showed the greatest interest in aggressive video material when they anticipated an opportunity to retaliate against a low status provocateur, but their interest was not greater than corresponding nonangered subjects. The effect of provocation upon interest in the other categories of video material was generally in line with what would be predicted from the theory. When there was no anticipated opportunity to retaliate, interest in humorous material was greater in provoked subjects than in those not provoked. In the case of the mildly erotic category of video selections, there was less interest expressed among provoked subjects when they anticipated having a chance to retaliate against a low status experimenter.     

Cross-modal transfer of conditioned suppression in rats: Effects of US intensity and extinction of the initial conditioning task

In conditioned suppression of water licking behavior by rats, we obtained data indicating general transfer of fear conditioning. A series of experiments resulted in two major findings. First, pairing of a neutral stimulus with a shock in the initial conditioning task facilitated acquisition of subsequent fear conditioning to another neutral stimulus, if the conditioned fear of the initial task was extinguished prior to the second task and if equally strong shocks were employed in both conditioning tasks. Second, omission of the extinction treatment or employment of weaker shocks in the initial task resulted in retardation, rather than facilitation, of the second conditioning task. An application to human clinical settings is discussed.     

Pavlovian phenomena in conditioned acceleration—Stimulus summation

Four naive male rats were separately fear-conditioned to two stimuli (light and sound) by pairing these stimuli with shocks. During Sidman avoidance these unreinforced stimuli elicited increases in response rates (conditioned acceleration). In a multiple schedule with light-shock and sound-shock reinforcements in the first component, the rats were tested for summation effects in the second (avoidance) component by presenting the light twice, the sound twice and the compound twice. They were then extinguished by eliminating the shocks in the first component. The effects of compounding were evidenced by: (1) a sizeable and reliable amplitude increase to the compound stimulus during conditioning; (2) a smaller and less consistent decrease in latencies during conditioning in all four subjects; and (3) a greater resistance to extinction for the compound stimulus as measured by mean amplitudes for all four subjects and on six of seven extinction sessions. Latency data during extinction were inconclusive. An additional unexpected finding was what appeared to be a two-factor secondary extinction of the avoidance itself as a result of Pavlovian extinction. The responding in the first four minutes of avoidance was inhibited to such an extent that the number of shocks received during this period increased 700 per cent from the last three conditioning sessions to the first three extinction sessions.     

Instigation to aggress and escalation of aggression examined from a personological perspective: The role of irritability and of emotional susceptibility

Two studies were conducted using Buss hostility machine paradigm to investigate the role of individual differences in irritability and emotional susceptibility on the instigation to aggress by a self-esteem lowering manipulation and on the hypothesized escalation of aggression over trials. The role of sex was also examined. In the first study, 60 highly irritable and 60 low irritable subjects were given the opportunity to deliver electric shocks to an experimental confederate, half after being provoked by a negative judgement on their performance in a learning task, half without such an experience. Each group of subjects was divided equally between males and females. It was found that highly irritable subjects, both males and females, delivered higher shocks after provocation than low irritable subjects under similar circumstances. An upward drift of shock level over trials was found only in provoked males and only in highly irritable females. In the second study, 60 highly emotionally susceptible and 60 low emotionally susceptible males and females were given the opportunity to deliver electric shocks to an experimental confederate, half after experiencing provocation, half without such an experience. It was found that provoked subjects delivered higher shocks than unprovoked subjects and that highly emotionally susceptible subjects delivered higher shocks than low emotionally susceptible subjects. Whereas an upward drift of shock levels over trials was found only in provoked males, the same effect was found in females, whether provoked or not. These findings are discussed in terms of the importance of stable personality characteristics that may mediate aggressive response.     

Blocking and unblocking of conditioned analgesia

Two experiments with rat subjects assessed the blocking phenomenon using inhibition of responding to painful thermal stimulation as an index of conditioned analgesia established through conditioned stimulus (CS)-shock pairings. In Experiment 1, a group of rats receiving the standard blocking procedure ($\text{A+}\text{AB+}$) showed shorter response latencies during a hot plate test of pain sensitivity in the presence of the added CS than groups of rats receiving various blocking control procedures. Experiment 2 replicated the blocking outcome of Experiment 1 and also demonstrated that the addition of a second shock unconditioned stimulus (US) during the compound conditioning phase attenuated the blocking effect; i.e., unblocking was observed. However, the deletion of a second shock US during compound conditioning in a group that had received two shocks on each trial in the first phase of the experiment failed to result in unblocking. These data extend the associative account of conditioned analgesia to situations involving stimulus selection and the implications for the analysis of aversive learning are discussed.     

Contextual control of appetitive conditioning: Influence of a contextual stimulus generated by a partial reinforcement procedure

Three experiments with rat subjects examined the effects of a context switch after conditioning treatments in which the conditioned stimulus (CS) was either paired with food on every presentation (continuous reinforcement) or on some of its presentations (partial reinforcement). In each experiment, a target CS was given one of these treatments in Context A, and another CS was given a treatment during sessions that were intermixed in Context B. Final tests of the target CS in Context A and Context B often revealed no loss of responding with the switch to B. However, a loss was observed when partial reinforcement had been associated with Context A and continuous reinforcement had been associated with Context B. Those conditions caused equal decrements in responding to partially reinforced and continuously reinforced targets. The results suggest that under the present conditions partial reinforcement can generate a contextual stimulus that becomes associated with the physical context and controls responding to the CS.     

The fear potentiated startle effect

A differential conditioning study examined whether an acoustic startle probe, presented during extinction of an aversively conditioned visual stimulus, potentiated the reflex eyeblink response in humans and whether this potentiation varied with the change in affective valence of the conditioned stimulus. Sixty college students were randomly assigned to view a series of two slides, depicting either unpleasant/highly arousing, unpleasant/moderate arousing, neutral/calm, pleasant/moderate arousing or pleasant/highly arousing scenes and objects (duration: 8 sec). During preconditioning (8 trials) and extinction (24 trials) acoustic startle probes (white noise bursts [50 ms; 95 dBA] were administered during and between slide presentation). During acquisition (16 trials) CS+ was reinforced by an electric shock. Startle response magnitudes significantly increased from preconditioning to extinction and were substantially larger to CS+. Conditioned startle reflex augmentation linearly increased with the pleasantness of the slides. Furthermore, subjects showed a greater post-conditioning increase of judged aversiveness to slides that they had previously reported to be more pleasant, exactly paralleling the startle reflex results.

     

Exposure to pornography,permissive and nonpermissive cues,and male aggression toward females

The present study examined the role of permissive and nonpermissive cues in mediating the relationship between exposure to erotica and aggression. Male subjects viewed either neutral slides with a silent female or erotic slides with a female who made permissive, nonpermissive, or no comments about the slides. The males rated the slides and subsequently rated the female confederate. Male subjects were then given an opportunity to administer their choice of several intensities of shock to the female in a competitive reaction-time task. Subjects in the permissive cues condition rated the erotic slides as more arousing, saw the female as more reasonable and accepting, and selected more intense shocks for the female than did subjects in the other conditions. One explanation of these results is that permissive cues in the presence of erotica led the male to believe that other normally inappropriate behaviors would be tolerated.     

Reevaluation of things past

The ability of rats to reevaluate previously presented information in light of subsequently provided information was evaluated using a CER (conditioned emotional response) procedure. In Experiment 1, rats suppressed responding to a compound light + tone stimulus that was repeatedly paired with shock. Groups of rats were then presented with only one element of the compound (the tone), either presented alone or paired with shock, for 15 days. During this 15-day period, two control groups received trials with the shock alone or neither stimulus nor shock. All of the rats were then tested with the other element of the compound (the light). Rats that had received the tone paired with shock during the intervening training continued to suppress to the light, whereas rats that had received the tone alone showed rapid extinction of the CER to light. The control groups showed that this effect was not due to the number of shock presentations received. A subsequent experiment also demonstrated that these results were not due to nonspecific stimulus effects. Apparently, a subsequent change in the associative strength of one element results in a similar change to the other element of a previously established compound stimulus.