Relationship between projective and direct measures of fear arousal.

The present study reports on the use of a projective measure which in 2 independent replications appeared to be a valid measure of level of induced fear, and which showed a high correlation (+.75) with a direct response scale. However, the data suggest that despite the magnitude of their relationship, the 2 measures are differentially sensitive to expressions of motivation which reflect the Ss' general style of defensive emotional response. Ss who reported themselves as being reticent in expressing their feelings of pain showed greater fear arousal on the projective measure than on the direct measure, while the opposite was true of Ss who reported that they were likely to express their pain to others (p     

Classical conditioning of autonomic fear responses is independent of contingency awareness.

The role of contingency awareness in classical conditioning experiments using human subjects is currently under debate. This study took a novel approach to manipulating contingency awareness in a differential Pavlovian conditioning paradigm. Complex sine wave gratings were used as visual conditional stimuli (CS). By manipulating the fundamental spatial frequency of the displays, we were able to construct pairs of stimuli that varied in discriminability. One group of subjects was given an “easy” discrimination, and another was exposed to a “difficult” CS+ and CS–. A 3rd group was exposed to a stimulus that was paired with the unconditional stimulus (UCS) 50% of the time and served as a control. Skin conductance response (SCR) and continuous UCS expectancy data were measured concurrently throughout the experiment. Differential UCS expectancy was found only in the easy discrimination group. Differential SCRs were found in the easy discrimination group as well as in the difficult discrimination group, but not in the 50% contingency control. The difficult discrimination group did not exhibit differential UCS expectancy but did show clear differential SCR. These observations support a dual process interpretation of classical conditioning whereby conditioning on an implicit level can occur without explicit knowledge about the contingencies. The role of contingency awareness in classical conditioning experiments using human subjects is currently under debate. This study took a novel approach to manipulating contingency awareness in a differential Pavlovian conditioning paradigm. Complex sine wave gratings were used as visual conditional stimuli (CS). By manipulating the fundamental spatial frequency of the displays, we were able to construct pairs of stimuli that varied in discriminability. One group of subjects was given an “easy” discrimination, and another was exposed to a “difficult” CS+ and CS–. A 3rd group was exposed to a stimulus that was paired with the unconditional stimulus (UCS) 50% of the time and served as a control. Skin conductance response (SCR) and continuous UCS expectancy data were measured concurrently throughout the experiment. Differential UCS expectancy was found only in the easy discrimination group. Differential SCRs were found in the easy discrimination group as well as in the difficult discrimination group, but not in the 50% contingency control. The difficult discrimination group did not exhibit differential UCS expectancy but did show clear differential SCR. These observations support a dual process interpretation of classical conditioning whereby conditioning on an implicit level can occur without explicit knowledge about the contingencies. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The moderating effects of stimulus valence and arousal on memory suppression.

This study examined the separate and combined effects of stimulus valence and arousal on retrieval inhibition. Participants performed Anderson and Green's (2001) memory suppression task with stimuli varying across dimensions of valence and arousal. Memory was tested through free and cued recall as well as speeded recognition. Results showed that both stimulus valence and arousal influenced the extent to which participants successfully inhibited retrieval, but not in the ways anticipated. Specifically, the strongest inhibition effects were for highly arousing, pleasant words. In addition, unpleasant stimuli that were suppressed were better recalled during both cued and free-recall tasks than pleasant stimuli that were suppressed. Across all tests of memory performance, there were no significant differences between the experimental conditions for highly arousing, unpleasant words. The implications of these findings are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of fear arousal and suppression of fear upon social perception.

A research was designed to study the effects of fear arousal and suppression of fear upon social perception. "It was hypothesized that individuals subjected to a fear-producing situation would tend to project their feelings upon some social objects, and further, instructions to inhibit emotional reactions would increase the amount of projection." Sixty male volunteers from introductory psychology classes were randomly assigned to one of three groups: Control, Fear-Expression and Fear-Suppression. "The data indicate that the arousal of fear results in a tendency to project fear onto a stimulus object in the environment. The results are also consistent with the hypothesis that suppression facilitates the tendency to project although, in this latter instance, one is less confident in rejecting the null hypothesis. Several alternative explanations of the effects of the suppression variable were considered and the role of cognitive variables in the projection process were discussed." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of fear arousal upon task performance and verbal behavior.

80 undergraduate females were classified as being either high or low in fear of speaking in front of a group. ? were told that they were to speak following a task; the remaining Ss did the task without expecting to speak. All Ss spoke about the task for 1 min. immediately following the task. Experimental Ss took significantly longer to perform the task, and naive judges were able to detect differences in the verbal productions of the groups. Formal aspects of S's verbal productions also discriminated among high- and low-fear Ss. Implications for theory and importance of assessing different types of behavior are briefly discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Temporal gradient of fear arousal in psychopaths.

Skin conductance of psychopathic (P) and nonpsychopathic (NP) criminals and noncriminal controls (N = 11 each group) was monitored while the numbers 1-12 were consecutively presented on a memory drum. After the 1st trial, Ss were informed that on each of the remaining 5 trials they would receive a strong electric shock when Number 8 appeared. Log conductance increases in the interval prior to shock were significantly smaller and began later for the P than for the NP Ss. The psychopaths were less responsive to shock than were the NP criminals but did not differ significantly from the noncriminal controls. There were no significant differences among groups in the rate of recovery from the effects of shock. The results were consistent with the hypothesis that the temporal gradient of fear arousal and response inhibition is steeper for psychopaths than for normal persons. (20 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Steady-state methadone effect on generalized arousal in male and female mice.

Methadone is widely used in treatment of short-acting opiate addiction. The on-off effects of opioids have been documented to have profound differences from steady-state opioids. The authors hypothesize that opioids play important roles in either generalized arousal (GA) or aversive state of arousal during opioid withdrawal. Both male and female C57BL6 mice received steady-state methadone (SSM) through osmotic pumps at 10 or 20 mg/kg/day, and GA was measured in voluntary motor activity, sensory responsivity, and contextual fear conditioning. SSM did not have any effect on those GA behaviors in either sex. Females had higher activity and less fear conditioning than males. The effects of SSM on stress-responsive orexin gene expression in the lateral hypothalamus (LH) and medial hypothalamus (MH, including perifornical and dorsomedial areas) were measured after the behavioral tests. Females showed significantly lower basal LH (but not MH) orexin mRNA levels than males. A panel of GA stressors increased LH orexin mRNA levels in females only; these increases were blunted by SSM at 20 mg/kg. In summary, SSM had no effect on GA behaviors. In females, SSM blunted the GA stress-induced LH orexin gene expression. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Effects of Fear and Anger Facial Expressions on Approach- and Avoidance-Related Behaviors.

The facial expressions of fear and anger are universal social signals in humans. Both expressions have been frequently presumed to signify threat to perceivers and therefore are often used in studies investigating responses to threatening stimuli. Here the authors show that the anger expression facilitates avoidance-related behavior in participants, which supports the notion of this expression being a threatening stimulus. The fear expression, on the other hand, facilitates approach behaviors in perceivers. This contradicts the notion of the fear expression as predominantly threatening or aversive and suggests it may represent an affiliative stimulus. Although the fear expression may signal that a threat is present in the environment, the effect of the expression on conspecifics may be in part to elicit approach. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Opioid Receptors Regulate the Extinction of Pavlovian Fear Conditioning.

Rats received a single pairing of an auditory conditioned stimulus (CS) with a footshock unconditioned stimulus (US). The fear (freezing) that had accrued to the CS was then extinguished. Injection of naloxone prior to this extinction significantly impaired the development of extinction. This impairment was mediated by opioid receptors in the brain and was not observed when naloxone was injected after extinction training. Finally, an injection of naloxone on test failed to reinstate extinguished responding that had already accrued to the CS. These experiments show that opioid receptors regulate the development, but not the expression, of fear extinction and are discussed with reference to the roles of opioid receptors in US processing, memory, and appetitive motivation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Morphine promotes autonomic learning.

Morphine (0.01-10 mg/kg) promoted rapid autonomic learning of discriminative, Pavlovian conditioned heart rate decelerations to tone signals in male and female rabbits, and the higher doses (1-10 mg/kg) promoted decelerative heart rate orienting reflexes to novel tones. Morphine does dependently reduced heart rate acceleration to signaled shock but had no effect on heart rate acceleration to unsignaled shock. Morphine did not impair retention of cardiac conditioned reflexes, and its U-shaped dose effect, increasing conditioned heart rate discrimination early in training, reappeared in extinction. The authors propose that morphine promotes autonomic learning of preparatory, compensatory reflexes to signaled stressors that reduce their stressful effects. This action may mimic the normal, adaptive function of an endogenous messenger released by the Pavlovian contingency. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Acute cortisol elevations cause heightened arousal ratings of objectively nonarousing stimuli.

To test the effects of cortisol on affective experience, the authors orally administered a placebo, 20 mg cortisol, or 40 mg cortisol to 85 men. Participants' affective responses to negative and neutral stimuli were measured. Self-reported affective state was also assessed. Participants in the 40-mg group (showing extreme cortisol elevations within the physiological range) rated neutral stimuli as more highly arousing than did participants in the placebo and 20-mg groups. Furthermore, within the 20-mg group, individuals with higher cortisol elevations made higher arousal ratings of neutral stimuli. However, cortisol was unrelated to self-reported affective state. Thus, findings indicate that acute cortisol elevations cause heightened arousal in response to objectively nonarousing stimuli, in the absence of effects on mood. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Experiencing activation: Energetic arousal and tense arousal are not mixtures of valence and activation.

R. E. Thayer (1989) proposed 2 types of activation: energetic arousal (awake-tired) and tense arousal (tense-calm). This view has been challenged by claims that energetic arousal and tense arousal are mixtures of valence and a single activation dimension. The authors present a direct test of this hypothesis by computing the correlation between the residuals of energetic arousal and tense arousal after removing the shared variance with valence. Whereas the valence activation hypothesis predicts a strong positive correlation between the 2 residuals, the authors found that it was not significantly different from 0. This finding reaffirms the view of energetic arousal and tense arousal as 2 distinct types of activation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fear and social comparison.

Schachter (1959) had found a positive relationship between fear and the desire to be with others (affiliation). Schachter concluded, following Festinger (1954), that a person will attempt to reduce cognitive dissonance with regard to his self-picture in terms of information obtainable from others. This investigation attempts to determine the validity of this hypothesis by focusing on the dimension of the intensity of the emotion. "If a person is uncertain as to the intensity of his emotional reaction, he should seek information from others that will help him measure it. To the extent that he has information from others regarding the intensity of their reactions, his desire to be with them prior to the impending experience should be reduced." The hypothesis was supported; however, factors such as sex and order of birth were seen to affect S's reaction to threat. From Psyc Abstracts 36:04:4GE86G. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Estradiol and orexin-2 saporin actions on multiple forms of behavioral arousal in female mice.

Estrogens modulate almost all aspects of female behavioral arousal; however, apart from that of sexual behavior, the neurobiology of female arousal remains unclear. Because orexins-hypocretins are neurotransmitters known to be important for behavioral arousal, the authors hypothesized that orexins may be a target for estrogen. Gonadectomized female mice received an intracerebral injection of either phosphate-buffered saline, the neurotoxin saporin (SAP), or the orexin-2-saporin conjugate (OXSAP) in the lateral hypothalamus. SAP- and OXSAP-treated mice were also divided into groups receiving either estradiol capsules or oil capsules. Mice were tested in 3 behavioral tests measuring different modes of arousal: sensory responsiveness, running wheel activity, and fearfulness. OXSAP mice showed decreases in sensory responsiveness and fearfulness concomitant with a reduction in orexin cell number. Estradiol affected all behaviors tested but decreased fearfulness only when combined with OXSAP treatment. These data indicate that estrogens modulate orexins' effects on fearfulness. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

D-Cycloserine and the Facilitation of Extinction of Conditioned Fear: Consequences for Reinstatement.

Several recent studies have reported that D-cycloserine (DCS), a partial N-methyl-D-aspartate agonist, facilitates extinction of learned fear in rats. Other studies have shown that representation of the unconditioned stimulus (US) can reinstate learned fear after extinction. This study examined whether this reinstatement effect occurs in Sprague-Dawley rats given DCS at the time of extinction. Results showed that saline-treated rats exhibited the reinstatement effect but DCS-treated rats did not (Experiments 1 and 2). This lack of reinstatement in DCS-treated rats was not due to residual effects of DCS on either US or context processing (Experiment 3). Overall, these results (a) raise questions about the mechanisms underlying DCS facilitation of extinction and (b) suggest that DCS might have substantial practical benefit. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fear of failure, achievement motivation, and aspiring to prestigeful occupations.

From a list of 40 occupations, 67 male undergraduates were asked (a) which occupation was nearest the one they intended to strive for, (b) what satisfaction could be expected from each occupation listed, (c) which were realistically attainable, and (d) which would they settle for if the stress of occupational achievement could be avoided. As fear of failure (FF) increased (a) the prestige of aspired-to occupations decreased, (b) willingness to settle for less satisfying and less prestigeful occupations increased, and (c) the person became more likely to perceive that occupations with extremely low probabilities of attainment were within his reach. Effects of achievement motivation were very weak but generally in a direction opposite to that of FF. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Impact of Healthy Aging on Awareness and Fear Conditioning.

Fear conditioning has provided a useful model system for studying associative emotional learning, but the impact of healthy aging has gone relatively unexplored. The present study investigated fear conditioning across the adult life span in humans. A delay discrimination task was employed using visual conditioned stimuli and an auditory unconditioned stimulus. Awareness of the reinforcement contingencies was assessed in a postexperimental interview. Compared with young adult participants, middle-aged and older adults displayed reductions in unconditioned responding, discriminant conditioning, and contingency awareness. When awareness and overall arousability were taken into consideration, there were no residual effects of aging on conditioning. These results highlight the importance of considering the influence of declarative knowledge when interpreting age-associated changes in discriminative conditioned learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Temporal Encoding in Fear Conditioning Revealed Through Associative Reflex Facilitation.

[Correction Notice: An erratum for this article was reported in Vol 118(3) of Behavioral Neuroscience (see record 2007-16851-001). The article contained several errors. On page 396, second paragraph, the sentence beginning on line 6 should read as follows: "Having a stable baseline is critical for studies of reflex facilitation because the experimental designs invariably entail repetitive CR testing, if only to achieve reasonable statistical power (see Choi et al., 2001b; Lindquist & Brown, 2004)." On page 400, the first heading should read as follows: "Comparison of New and Old Reflex Facilitation Procedures". On page 400, the first sentence under the abovementioned heading should read as follows: "We decided not to use the original measure of reflex facilitation, developed by J. S. Brown et al. (1951), because it suffers from severe interpretational limitations, elaborated in detail elsewhere (Choi et al., 2001b; Leaton & Cranney, 1990; Lindquist & Brown, 2004)."] Temporal encoding in Pavlovian fear conditioning was examined through conditional facilitation of the short-latency (Rl) component of the rat eyeblink reflex. Rats were fear-conditioned to a tone conditional stimulus (CS) with either a 3- or 9-s interstimulus interval (ISI) between CS onset and the onset of the grid-shock unconditional stimulus (US). Rl facilitation was tested over 2 days, in counterbalanced order, at a latency of 3 s and 9 s from CS onset. CS-produced Rl facilitation, the conditional response (CR), was 3-4 times larger when the test latency equaled the conditioning ISI. These results, coupled with the known neurophysiology of Rl facilitation, suggest that this CR could disclose differences in the time course of CS-generated output from the amygdala when driven by cortical versus subcortical CS-CR pathways. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

One-Trial Learning and Superior Resistance to Extinction of Autonomic Responses Conditioned to Potentially Phobic Stimuli.

Human subjects were exposed to pictures of potentially phobic (snakes) and supposedly neutral (houses) objects as conditioned stimuli (CSs) in a Pavlovian conditioning experiment with shock as unconditioned stimulus (US), and skin conductance and finger pulse volume as dependent variables. The skin conductance responses conditioned to phobic stimuli were acquired after one CS-US pairing, and showed practically no extinction, whereas the responses to neutral stimuli showed very little resistance to extinction after both 1 and 5 reinforcements. The superior resistance to extinction of the phobic condition was interpreted to be a specific associative effect. In general, the skin conductance acquisition data showed tendencies similar to those during extinction. For finger pulse volume responses, however, there were very weak conditioning effects, and no effect of stimulus. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Duchenne smile, emotional experience, and autonomic reactivity: A test of the facial feedback hypothesis.

This study examined the modulatory function of Duchenne and non-Duchenne smiles on subjective and autonomic components of emotion. Participants were asked to hold a pencil in their mouth to either facilitate or inhibit smiles and were not instructed to contract specific muscles. Five conditions--namely lips pressing, low-level non-Duchenne smiling, high-level non-Duchenne smiling, Ducherme smiling, and control--were produced while participants watched videoclips that were evocative of positive or negative affect. Participants who displayed Duchenne smiles reported more positive experience when pleasant scenes and humorous cartoons were presented. Furthermore, they tended to exhibit different patterns of autonomic arousal when viewing positive scenes. These results support the facial feedback hypothesis and suggest that facial feedback has more powerful effects when facial configurations represent valid analogs of basic emotional expressions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)