Arne Öhman

Unconscious anxiety : phobic responses to masked stimuli

We tested the hypothesis that an unconscious preattentive perceptual analysis of phobic stimuli is sufficient to elicit human fear responses. Selected snake- and spider-fearful Ss, as well as normal controls, were exposed to pictures of snakes, spiders, flowers, and mushrooms. A separate forced-choice recognition experiment established backward masking conditions that effectively precluded recognition of experimental stimuli both for fearful and nonfearful Ss. In the main experiment, these conditions were used to compare skin conductance responses (SCRs) to masked and nonmasked phobic and control pictures among fearful and nonfearful Ss. In support of the hypotheses, snake- and spider-fearful Ss showed elevated SCRs to snake and spider pictures as compared with neutral pictures and with responses of the nonfearful Ss under both masking conditions. Ratings of valence, arousal, and dominance indicated that the fearful Ss felt more negative, more aroused, and less dominant in relation to both masked and nonmasked phobic stimuli.

Automatically elicited fear: Conditioned skin conductance responses to masked facial expressions

Abstract This study examined automatic elicitation of conditioned skin conductance responses (SCRs), when a backward masking procedure prevented the subjects conscious awareness of the conditioned stimuli (CSs). The CSs were pictures of emotional facial expressions. A differential conditioning procedure was used. One facial expression (e.g. an angry face) was aversively conditioned by a shock unconditioned stimulus, whereas another facial expression (e.g. a happy face) was never presented with the shock. After conditioning, the CSs were presented backwardly masked by a neutral face. This procedure prevented conscious perception of the CS. Nevertheless, reliable differential SCRs were obtained when the CS had been an angry face. This effect, however, was dependent on the subjects direction of attention. When attention was focused on the mask, no differential responding was observed. Thus it was concluded that, when fear-relevant stimuli (angry faces) served as the CS, elicitation of SCRs was automatic in...

Electrodermal activity and vulnerability to schizophrenia: A review

Because electrodermal variables show consistency over time and situations, and evidence of genetic loading, it is of interest to examine such measures in adult schizophrenics and in children at risk for the disorder. Samples of adult schizophrenics are heterogeneous with regard to electrodermal activity. One group, the nonresponders, fails completely to respond to simple moderate intensity nonsignal stimuli. The other, the responders, does not differ from normals in frequency of response to nonsignal stimuli, but tends to show elevated tonic levels, and bilaterally asymmetrical and rapidly recovering responses. These two groups differ in other physiological and psychological measures, and in clinical picture. The responder pattern is predictive of poor outcome of acute schizophrenic episodes. A similar hyperactive pattern was found to differentiate children genetically at high or low risk for schizophrenia, and to predict psychiatric breakdown in the former group in Mednick and Schulsingers original high risk study. The relationship to risk has been less evident in later studies, but similar, albeit weaker, tendencies have been reported. It is concluded that the nonresponding pattern may be secondary to a clinical picture of withdrawal and confusion, whereas the responder pattern may index vulnerability to schizophrenic episodes. On the psychological level, it is argued that this relationship is best conceptualized in attentional terms couched in information-processing language.

Facial expressions as conditioned stimuli for electrodermal responses: a case of "preparedness"?

Converging data suggest that human facial behavior has an evolutionary basis. Combining these data with Seligmans preparedness theory, it was predicted that facial expressions of anger should be more readily associated with aversive events than should expressions of happiness. Two experiments involving differential electrodermal conditioning to pictures of faces, with electric shock as the unconditioned stimulus, were performed. In the first experiment, the subjects were exposed to two pictures of the same person, one with an angry and one with a happy expression. For half of the subjects, the shock followed the angry face, and for the other half, it followed the happy face. In the second experiment, three groups of subjects differentiated between pictures of male and female faces, both showing angry, neutral, and happy expressions. Responses to angry conditioned stimuli showed significant resistance to extinction in both experiments, with a larger effect in Experiment 2. Responses to happy or neutral conditioned stimuli, on the other hand, extinguished immediately when the shock was withheld. The results are related to conditioning to phobic stimuli and to the preparedness theory.

The Face of Wrath: Critical Features for Conveying Facial Threat

We examined the role of different facial features (shape of eyebrows, eyes, mouth, nose, and the direction of gaze) in conveying the emotional impact of a threatening face. In two experiments, a total of 100 high school students rated their impression of two sets of schematic faces in terms of semantic differential scales (Activity, Negative Evaluation, and Potency). It was found that the different facial features could be ordered hierarchically, with eyebrows as the most important feature, followed by mouth and eyes. Eyebrows thus fundamentally categorised faces as threatening or nonthreatening. The different shapes of mouth and eyes provided subsequent categorisations of faces within these primary categories.

Cognition and Event‐Related Potentials II. The Orienting Reflex and P300

This panel was expected to review the literature pertaining to the effects of novelty and surprise on E R P components, particularly the P300, and the literature on the orienting reflex (OR). This paper records the correspondence between members of the panel before the conference. I t consists of an edited version of the material that was circulated to the conference participants before the meeting. No major reconciliation of views resulted from the conference discussion, nor could one be expected, given the rather different perspectives adopted by the panelists. The issues presented raise questions that need to be considered by psychophysiologists. This paper, therefore,

PREPAREDNESS AND AROUSABILITY AS DETERMINANTS OF ELECTRODERMAL CONDITIONING.

Abstract ‘Arousability’, as defined through spontaneous electrodermal responses, has been empirically linked to anxiety, phobic symptoms and outcome of systematic desensitization. Previous data from our laboratory indicate that ‘preparedness’, as defined through potentially phobic vs. fear-irrelevant or ‘neutral’ conditioned stimuh, is an important determinant of electrodermal conditioning. The present experiment compared groups selected to be high or low in spontaneous responding during differential conditioning to potentially phobic or neutral stimuh. It was found that the effects of these two factors were essentially additive, i.e. conditioning and resistance to extinction were better for phobic stimuli and for high-arousal groups. The high-aroused group with phobic stimuh showed diffuse responding during acquisition, not differentiating between reinforced and unreinforced cues. However, it was the only group that failed to extinguish during 20 trials, which indicates that high arousal gives superior resistance to extinction particularly for phobic stimuli.

Preattentive processing, preparedness and phobias: Effects of instruction on conditioned electrodermal responses to masked and non-masked fear-relevant

We hypothesized that autonomic responses conditioned to fear-relevant stimuli, in contrast to responses conditioned to neutral stimuli, can be elicited after only an automatic, non-conscious analysis of the stimulus. Consequently, they may be expected to be insensitive to verbal instructions. Normal subjects were conditioned to either fear-relevant stimuli (snakes or spiders) or neutral stimuli (flowers or mushrooms) in a differential conditioning paradigm with shock as the unconditioned stimulus. In a subsequent extinction series, half of the subjects were shown the conditioned stimuli under masking conditions preventing their conscious recognition, whereas the other half were exposed to non-masked stimuli. Then half of the subjects in each of the masking conditions were verbally instructed that no more shocks would be delivered and then the extinction trials followed. Consistent with our hypothesis, differential responses to the fear-relevant CSs+ and CSs- remained unaffected by both masking and instruction, whereas differential responding to neutral stimuli was wiped out by the masking procedure and the verbal instruction.

Modeling processes in the acquisition of fears: vicarious electrodermal conditioning to fear-relevant stimuli.

Fear-relevant (snakes, spiders, and rats) and fear-irrelevant (flowers, mushrooms, and berries) pictures were compared as conditioned and instigating stimuli in a vicarious classical conditioning paradigm with skin conductance responses as the dependent variable. A female confederate model and subject watched the pictures side by side. A female stimulus presentations, the experimenter interrupted to investigate alleged overreactions of the model to one of the stimulus classes. The model then vividly described a phobia for this object, which was to serve as a vicarious instigating stimulus. The experiment continued for a few conditioning trials, and then the experimenter announced that the disturbing stimulus would be omitted before the second part of the experiment. There was no effect of stimulus content on vicariously instigated responses, although significant overall instigation was observed. However, the responses to the stimulus that was paired with the models phobic stimulus, that is, the vicariously conditioned responses, failed to extinguish during the second part of the experiment when it was fear-relevant but extinguished immediately when it was fear-irrelevant.

Habituation of the electrodermal orienting reaction to potentially phobic and supposedly neutral stimuli in normal human subjects

Abstract Three experiments concerning habituation of the electrodermal orienting response to pictures of phobic and neutral objects in normal human subjects are reported. In the first one, two independent groups were given either 16 presentations of snake pictures, or 16 presentations of pictures of houses. The pictures differed between subjects but a certain subject saw the same pictures throughout the experiment. The results showed no significant difference between groups in response magnitude, but significantly fewer trials to habituation in the group given neutral pictures. The second experiment used a within-subject design, with mixed presentation of either a snake and a house picture, or a spider and house picture. The responses to phobic stimuli were larger than those to neutral ones, and the latter took significantly fewer trials to habituate. The third experiment used a between-subject design where some shocks were given before the experiment, and the subject was threatened that some shocks would also be given during the experiment. This procedure potentiated the difference between the stimuli, so that the responses to the phobic pictures were about four times as large as those to the neutral stimuli.