Compensatory and mimetic conditioned responses to effects of heroin in addicted persons

Study 1: The aim of this study was to analyze in persons detoxified of heroin, compensatory conditioned responses (CCRs) that are opposite to the unconditioned physiological, and subjective effects that are induced by this substance. The procedure consisted in presenting slides with images of neutral stimuli (NSs) and conditioned stimuli (CSs) of heroin to both non-addicted and detoxified addicted persons. The evaluated responses were heart rate (HR) and desire for heroin (DH). Study 2: The aim was to facilitate the emission of mimetic conditioned responses (MCRs) to the unconditioned physiological, and subjective effects of heroin in detoxified heroin addicts. Three different stimulus series were manipulated: SA, during which the participant remained alone; SB, administration of a needle prick given by the researcher; SC, performance of the "pump" ritual without drug by the participants. The responses measured were HR and DH. The results of both studies are considered, respectively, to be indicators of compensatory and mimetic conditioned responses.     

Arousal transfer: The influence of fear arousal on subsequent sexual arousal for subjects with high and low sex guilt

Male subjects (N = 128) with high or low sex guilt either were or were not threatened with shock (fear arousal manipulation) and then viewed either an erotic or a neutral film (sex arousal manipulation). Then all subjects viewed and rated slides of attractive women and slides of landscapes (neutral control slides). If fear arousal was specifically transferred to sexual arousal as is often predicted rather than simply causing a general increase in arousal, then it would be expected that subjects who had been exposed to the threat would show high arousal in response to the slides of women and low arousal to the slides of landscapes, whereas subjects who had not been threatened would show low arousal to both the slides of women and landscapes. Physiological (pulse rate, skin resistance), self-report, and word association measures consistently indicated that (a) both of the arousal manipulations were effective, (b) the slides of women were arousing, (c) sex guilt influenced responses as would be expected from previous research, but (d) did not indicate support for arousal transference. These findings (a) provide information concerning the influence of guilt on drives, (b) raise questions about the transfer of arousal that was noted in less controlled investigations, and (c) highlight the need for additional controls in research of this type.     

Psychophysiological and subjective reactions of social phobics and normals to facial stimuli

Nine social phobics and 9 normal control subjects were exposed to slides of angry faces, happy faces, and neutral objects (i.e. flowers or mushrooms). Skin conductance responses (SCRs) to the stimuli and eyeblink rate (EBR) during stimulus exposure were recorded. In addition, subjects were asked to rate the stimuli in terms of pleasantness. While angry face stimuli elicited greater SCRs, stronger inhibition of EBR, and were evaluated more negatively than the other stimuli, there were no differences between social phobics and normals in these respects. Thus, the findings lend no support to the idea that social phobics are particularly sensitive to facial cues in general or to negative facial cues in particular.     

Childhood anxiety and attention to emotion faces in a modified stroop task

This study used an emotional face stroop task to investigate the effects of self‐report trait anxiety, social concern (SC), and chronological age (CA) on reaction time to match coloured outlines of angry, happy, and neutral faces (and control faces with scrambled features) with coloured buttons in a community sample of 74 children aged 6 –12 years. The results showed an interference of colour matching for angry (relative to neutral) faces in children with elevated SC. The same effect was not found for happy or control faces. In addition, the results suggest that selective attention to angry faces in children with social concern (SC) was not significantly moderated by age.     

The incubation theory of fear/anxiety: experimental investigation in a human laboratory model of Pavlovian conditioning

The aim of this work was to test Eysenck's incubation theory of fear/anxiety in human Pavlovian B conditioning of heart rate (HR) responses. The conditioned stimuli (CSs) were phobia-relevant slides (snakes and spiders) and the unconditioned stimuli (UCSs) were aversive noises. The subjects were presented with two levels of noise intensity during acquisition and three levels of nonreinforced CS presentation (CS-only) in a delay differential (CS+/CS-) conditioning paradigm (2 x 3 x 2). Consistent with the incubation theory, conditioned HR acceleratory responses were sustained (resistance to extinction) for high-noise intensity and short-presentations of CS-only subjects. During the extinction phase, HR acceleratory responses quickly extinguished in low-noise intensity groups after the first presentations of CS-only. These findings were interpreted as support for the incubation theory of phobic fear.     

Covariation bias,classical conditioning,and phobic fear

The present study investigated whether phobics show an illusory correlation (IC) between phobia-relevant stimuli and aversive events. Nineteen treated and 19 untreated spider phobics were exposed to a series of 72 slides. Three different categories were used: Phobia-relevant slides (spiders), alternative fear-relevant slides (weapons), and neutral slides (flowers). Slides were randomly paired with either a shock, a siren, or nothing at all. All slide/outcome combinations occurred equally frequently. A posteriori recorded contingency estimates indicated that untreated phobics dramatically overestimate the covariation of spiders and shock. On-line recorded outcome expectancies revealed that the bias to overestimate the spider-shock contingency is highly resistant to extinction. The covariation bias was accompanied by differentially heightened electrodermal first interval responses (FIR) and unconditioned electrodermal responses (third interval responses: TIR) on phobia-relevant trials. Treated phobics did not show a covariation bias, indicating that such bias can be modulated by behavioral treatment. The present findings sustain the hypothesis that phobic subjects process information in a fear-confirming way.     

Brain asymmetry and autonomic conditioning: Sensitization control

In the present experiment we report effects of cerebral asymmetry, or laterality, during classical conditioning to facial emotional stimuli. Twenty-five female subjects were presented with slides of a happy face in one visual half-field (VHF), and simultaneously a slide of an angry face in the other VHF, followed by shock as the unconditioned stimulus (UCS). To control for effects of sensitization, a new stimulus, never associated with the UCS, was introduced in the extinction phase. Dependent measures were phasic heart rate responses (HR) and skin conductance responses (SCR). The HR results showed a significant right hemisphere effect for the CS-UCS association, that was not attributable to UCS sensitization. No significant effects were found for the SCRs. The basic HR finding was a right hemisphere superiority for learning of a conditioned association.     

Covariation detection in treated and untreated spider phobics.

Twenty treated and 18 untreated spider phobics were exposed to a series of 72 slides. Three different categories of slides were used: phobia-relevant slides (spiders), alternative fear-relevant slides (weapons), and neutral slides (flowers). Slides were randomly paired with either a shock, a tone, or nothing at all. Despite the absence of a systematic correlation between slides and outcomes, untreated phobics strongly overestimated the covariation between spider slides and shock. Treated phobics did not show a covariation bias, suggesting that such bias can be modulated by behavioral treatment. In addition, untreated subjects were more confident about their contingency estimates than were treated subjects. The present results fit with earlier studies.     

Stimulus properties of facial expressions and their influence on the classical conditioning of fear

The influence of particular stimulus properties of facial expressions of emotion upon associative learning to a neutral cue was examined in the present investigation. A compound stimulus, composed of either a fearful, happy, or neutral facial expression paired with a neutral cue (tone), signaled an aversive event (mild electric shock). Phasic change in skin conductance (SC) was used as the measure of associative learning. Analyses of variance revealed that subjects who saw a fearful expression paired with the tone gave larger SC responses to the fearful expression than to the tone. The opposite pattern was obtained for subjects who had a happy expression paired with the tone. Subjects who had the neutral expression paired with the tone showed no significant difference in their responses to the two stimuli. Results of the present investigation were consistent with those of an earlier study by Lanzetta and Orr (1980), and extend the earlier theoretical interpretations by suggesting that fear expressions function as excitatory stimuli and happy expressions act as inhibitory stimuli. Methodological changes in the present study, which include a shorter CS interval and asynchronous stimulus onsets, also extend the previous findings.This research was supported by National Science Foundation Grant No. 7912422-AO1 and by funds from the Lincoln Filene endowment to Dartmouth College.     

Emotional distraction unbalances visual processing

Brain mechanisms used to control nonemotional aspects of cognition may be distinct from those regulating responses to emotional stimuli, with activity of the latter being detrimental to the former. Previous studies have shown that suppression of irrelevant emotional stimuli produces a largely right-lateralized pattern of frontal brain activation, thus predicting that emotional stimuli may invoke temporary, lateralized costs to performance on nonemotional cognitive tasks. To test this, we briefly (85 ms) presented a central, irrelevant, expressive (angry, happy, sad, or fearful) or neutral face 100 ms prior to a letter search task. The presentation of emotional versus neutral faces slowed subsequent search for targets appearing in the left, but not the right, hemifield, supporting the notion of a right-lateralized, emotional response mechanism that competes for control with nonemotional cognitive processes. Presentation of neutral, scrambled, or inverted neutral faces produced no such laterality effects on visual search response times.     

False autonomic feedback: Effects of attention to feedback on ratings of erotic stimuli

This study examines the roles played by sound track type, attention to sound track, and meaning of sound track in mediating the effects of false autonomic feedback on attractiveness ratings of erotic stimuli. Male subjects were instructed either to ignore or to pay attention to a pulsed or continuous sound track that was described either as heart-rate feedback or as a neutral auditory stimulus while slides of nude females were shown. Slides associated with a change in either the pulsed sound track or the continuous-tone sound track (increase slides) were subsequently rated as significantly more attractive than those associated with steady sound (stable slides). This effect was contingent on the meaning given to the auditory stimuli, with subjects in the heart-rate condition showing a stronger tendency to rate increase slides more positively than stable slides, by comparison with subjects in the neutral sounds condition. Within the heart-rate condition, subjects told to pay attention to the feedback showed greater rating differences between these two types of slide than those told to ignore it. This pattern of findings contrasts with those of an earlier experiment (Parkinson & Manstead, 1981), where differential unpleasantness ratings of slides of skin diseases depended on the attention paid to the sound track but not on its meaning. It is concluded that the effects of false autonomic feedback are contingent upon the kind of emotional stimuli that are presented.This article is based on research supported by the Economic and Social Research Council (UK). We gratefully acknowledge the assistance of Andrew Gregory, who was responsible for the computer program used in generating the sound track, and we would like to thank the anonymous reviewers for their comments on a previous version of this paper.     

A Novel Demonstration of Enhanced Memory Associated with Emotional Arousal

The relationship between emotional arousal and long-term memory is addressed in two experiments in which subjects viewed either a relatively emotionally neutral short story (presented as a brief slide show) or a closely matched but more emotionally arousing story and were tested for retention of the story 2 weeks later. Experiment 1 provides essential replication of the results of Heuer and Reisberg (1990) and illustrates the common interpretive problem posed by the use of different stimuli (slides) in the neutral versus emotional stories. In Experiment 2, identical slides (and sequence) were used in both the neutral and arousal stores. Two different stories were created by varying the narration that accompanied each slide. In both experiments, subjects who viewed the arousal story both experienced a greater emotional reaction to the story than did the subjects who viewed the neutral story, and subsequently exhibited enhanced memory for the story. Subjects in Experiment 2 who viewed the arousal story also recalled more slides than did the subjects who viewed the neutral story. This effect was greatest for story phase 2, the phase in which the emotional slide narration occurred. Because this enhanced retention of the story slides cannot be explained by any differences in the slides themselves, the results provide new evidence to support the contention that emotional arousal influences long-term memory in normal human subjects.     

Remember me? Psychopathic traits and emotional memory in an undergraduate sample

We investigated the effects of psychopathy on emotional memory among a predominantly female undergraduate sample. Undergraduates (N = 153, mean age = 20.1; 80.1% female; 57.1% Caucasian) completed a facial memory task. Participants were presented with a series of faces (sad, scared, angry, happy, neutral), completed a self-report measure of psychopathy, and were presented with another series of faces (with some from the first phase, and some new). Participants were asked whether they recognized each face from the first set, and reaction time (RT) was measured. Although memory for emotional faces did not differ from neutral faces, there were main effects of emotion, gender and psychopathy on RT. A significant 3-way interaction revealed that males who were higher in psychopathy had slower RTs; they were slow to remember sad, angry and neutral faces. In conclusion, psychopathy may affect emotional memory differently across gender. Specifically, undergraduate men, but not women, with higher psychopathy levels may show impaired memory for emotional faces. Implications for future studies of emotional memory and psychopathy are discussed.     

Posture affects emotional responses: A Head Down Bed Rest and ERP study

Body posture, mainly represented by horizontal bed rest, has been found to be associated with cortical inhibition, altered perceptual and cognitive processing. In the present research, the influence of Head Down Bed Rest (HDBR) – a condition also termed simulated microgravity – on emotional responses has been studied. Twenty-two male subjects were randomly assigned to either Sitting Control or HDBR group. After 3-h, subjects attended to a passive viewing emotional task in which 75 IAPS slides, divided into 25 pleasant, 25 neutral and 25 unpleasant, were presented in random order for 6 s each, while EEG was recorded from F7, F8 and Pz locations. Results showed in Sitting Controls the expected greater P300 and Late Positive Potential (LPP) to pleasant and unpleasant compared with neutral slides, an effect which indicates greater processing of emotional arousing stimuli. The HDBR group showed smaller non-significant differences among all emotional conditions in both ERP components. Arousal and valence subjective evaluations, typically less sensitive to experimental manipulation, did not differentiate groups. The observed ability of HDBR to inhibit cortical emotional responses raises an important issue on the risk that astronauts underestimate a dangerous/threatening situation or that long-term bedridden inpatients develop depressive symptoms.     

The amygdala is involved in affective priming effect for fearful faces

The object of this study was to investigate whether the amygdala is involved in affective priming effect after stimuli are encoded unconsciously and consciously. During the encoding phase, each masked face (fearful or neutral) was presented to participants six times for 17ms each, using a backward masking paradigm. During the retrieval phase, participants made a fearful/neutral judgment for each face. Half of the faces had the same valence as that seen during encoding (congruent condition) and the other half did not (incongruent condition). Participants were divided into unaware and aware groups based on their subjective and objective awareness assessments. The fMRI results showed that during encoding, the amygdala elicited stronger activation for fearful faces than neutral faces but differed in the hemisphere according to the awareness level. During retrieval, the amygdala showed a significant repetition priming effect, with the congruent faces producing less activation than the incongruent faces, especially for fearful faces. These data suggest that the amygdala is important in unconscious retrieving of memories for emotional faces whether they are encoded consciously or unconsciously.     

The involvement of distinct visual channels in rapid attention towards fearful facial expressions

This paper reports five experiments demonstrating that the low spatial frequency components of faces are critical to the production of rapid attentional responses towards fearful facial expressions. In our main experiments, low spatial frequency (LSF) or high spatial frequency (HSF) face pairs, consisting of one fearful and one neutral expression, were presented on a computer screen for a brief period. Participants were required to identify as quickly as possible the orientation of a bar target that immediately replaced one of the faces. Responses were faster when targets replaced the location of LSF fearful faces, compared with LSF neutral faces. By contrast, there were no differences between responses to targets replacing HSF fearful versus HSF neutral faces. This facilitation in spatial orienting occurred specifically with short time intervals between faces and target, and is consistent with a rapid processing of fear cues from LSF inputs that can serve to guide attention towards threat events.     

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.