The informational impact of mood on effort mobilization: a study of cardiovascular and electrodermal responses

The impact of mood on effort quantified as autonomic adjustments was investigated in an experiment. The authors induced positive versus negative moods with either 1 of 2 mood induction procedures (music vs. autobiographical recollection) that differed in the extent of required effort. Then participants performed an achievement task after demand appraisals were made. Results were as predicted. During the mood inductions, autonomic reactivity (systolic blood pressure [SBP], diastolic blood pressure, heart rate, skin conductance responses) was stronger in the relatively effortful recollection conditions than in the relatively effortless music conditions. Mood valence had no impact here. But in the context of task performance, the authors found (a) mood congruency effects on the demand appraisals that reflected subjectively higher demand in a negative than in a positive mood, and (b) stronger SBP reactivity in a negative mood compared with a positive mood. Furthermore, SBP reactivity during task performance was correlated with achievement.     

Some psychological determinants of electrodermal responses to deception

This study explores some of the psychological determinants of electrodermal responses to deception. There were four groups of 24 subjects, consisting of normal males and females, and personality-disordered males and females. The deceptive paradigms used consisted of three guilty knowledge card tasks that differed in the nature of the stimuli used and in procedural instructions. There was also a general question task involving five neutral questions and two emotive moral questions. After each task self-report analogue scales were administered in order to record the subjects' reactions to each task and the type of countermeasure they had used. The subjects also completed the Eysenck Personality Inventory, the Gough Socialization Scale and the Arrow-Dot test. Detectability on card tasks was found to relate to the following: procedural instructions, countermeasure strategies, involvement in the task, the extent to which the critical items are processed into memory, and lack of confidence in one's ability to beat the machine. Personality factors of Introversion, Neuroticism and Ego control had some significant correlations with differential responsivity but this was not consistent across subject samples or tasks. Differential responsivity to questions raising moral issues did not relate significantly to whether or not the subject admitted or denied such behaviour.     

Differentiation between vicarious instigation and classical conditioning of electrodermal responses

In past research of vicarious conditioning when a conditioned stimulus (CS) was repeatedly presented both to a model and an observer, the observer's reaction to the CS may have been the result of a vicariously conditioned reaction to the CS, as well as a vicariously instigated reaction to the inferred emotional state of the model who anticipates the reception of a noxious stimulus when the CS is presented. In order to partial out these two reactions, the present experiment employed 32 subjects of both sexes who took part in a two-group study of differential, vicarious classical conditioning of skin conductance responses. In one of the group, the tones serving as CS+ and CS- and which preceded the aversive and non aversive events to the mode, were presented over earphones to both the confederate model and the observer subject. In the second group, only the subjects had earphones on and were led to believe that the model was not aware of the CS presentations. This eliminated the possibility of vicariously instigated reactions. Although the conditioning effects produced in the present study were somewhat weak, results clearly showed equal levels of vicarious instigation and conditioning in the two groups. These results indicate that the potential confounding of these two reactions studies has not significantly affected result or conclusions from previous studies.     

SCORIT: A computer subroutine for scoring electrodermal responses

Given digitized electrodermal response records sampled at a rate of 20/sec and at a sensitivity level between 140 and 170 ohms, a computer subroutine for scoring skin resistance responses is described. It is designed to score multiple responses on a trial, which makes it particularly suitable for classical conditioning experiments involving long interstimulus intervals. The subroutine returns to the main program response latency, base resistance, peak resistance, and time from base to peak. Since SCORIT is written in FORTRAN IV, it can be employed in virtually any modern central computing facility at costs substantially below those involved in hand scoring.     

Heart-rate and electrodermal orienting responses to visual stimuli differing in complexity

Orienting response (OR) theory predicts that amount of information in the stimulus, or stimulus complexity, should be an important determinant of OR elicitation and habituation, more intense and more slowly habituating ORs being expected to complex than to simple stimuli. This prediction was tested in an experiment where subjects were exposed to simple and complex visual stimuli in randomized order, while heart-rate and skin conductance were measured. Complex stimuli evoked a more pronounced deceleratory heartrate response than did simple stimuli. However, the two conditions did not differ in rate of habituation of this response. For skin conductance responses, on the other hand, the complex stimulus took more trials than the simple stimulus to reach habituation, whereas the two conditions did not differ in response magnitude. Thus, the hypothesis of more intense orienting to complex stimuli was supported by the heart-rate data, and that of slower habituation to complex stimuli, of the skin conductance data.     

The relation of vicarious to direct instigation and conditioning of electrodermal responses

Abstract.— Three groups with 16 Ss each and run in pairs, participated in a differential, successive components, long interstimulus interval conditioning paradigm with the skin conductance response as dependent variable. For the problem solving group the task was described as guessing which of two lamps (CS₂s) would follow after two different tones (CS₁s). In the observer group they were further informed that the other subject in the pair, the model, would receive shocks at CS+ offset, which actually was the case for the model group. Skin conductance responses were scored in five intervals during and after the non-overlapping presentation of the two CSs with a duration of 8 sec each. The results indicated no differentiation in any interval for the problem-solvers, and parallel instigation to shock and threat of shock, and conditioning in the observer and model groups, with the exception of conditioning in the 1st interval for observers only. The results were interpreted as parallel instigation and conditioning between vicarious and direct learning, the reported difference being due only to different UCS-intensities causing a blocking of first-order conditioning in the model but not in the observer group.     

Conditioning of electrodermal responses through vicarious instigation and through perceived threat to a performer

Abstract.— In order to demonstrate vicarious classical conditioning, and to investigate the necessity of vicarious instigation for vicarious conditioning of skin conductance responses, two groups of 32 students each observed a performer ( P ) allegedly trying to solve easy and difficult number series displayed for both the P and the observers ( Os ). Difficult problems served as CS+ and easy ones as CS-for os in both groups; indicated shock to the P as unconditioned stimulus (UCS) for one group, and perceived threat of shock to P as UCS for the other. Within the two groups half of the os were instructed to empathize with the P , whereas the other half was instructed just to watch her movements. The results demonstrated vicarious instigation and conditioning for the group having indicated shock as UCS, and conditioning without instigation for the group having perceived threat of shock as UCS. Since results for the conditioned response and the vicariously instigated response go beyond earlier interpretations, a theoretical elaboration in the cognitive direction is argued for.     

Lateral asymmetries in electrodermal responses to nonattended stimuli: a reply to Walker and Ceci

Walker and Ceci (1983) pose a number of interesting and potentially important criticisms and alternative explanations regarding the laterality finding and hypothesis of Dawson and Schell (1982). The present evaluation finds each of the criticisms and alternative explanations to be inadequate. We then distinguish between two alternative interpretations of the Dawson and Schell hypothesis, one based on inherent functional properties of the two hemispheres and the other based on the notion that each hemisphere is a partially independent pool of processing resources. Walker and Ceci's fundamental objection seems to apply only to the first interpretation.     

Lateral asymmetries in electrodermal responses to nonattended stimuli: a response to Dawson and Schell

Recently, Dawson and Schell (1982) provided convincing evidence that words presented to the nonattended ear during a dichotic-listening task undergo automatic semantic analysis in the absence of intention or awareness. Because of its methodological rigor, this finding is important in the context of the long-standing controversy surrounding the preattentive processing phenomenon. However, we challenge the authors' suggestion of a right-hemisphere locus for this phenomenon. We offer a methodological basis for the findings and propose a countersuggestion of a left hemisphere, or at least bilateral, processing locus.     

Resistance to extinction of conditioned electrodermal responses: a study of the incubation fear hypothesis

In the present study we examined Eysenck's incubation hypothesis of fear. Probability of skin conductance response (SCR) was analyzed for a sample of 79 undergraduate women, ranging in age from 18 to 25 years. Different groups of participants were conditioned to two levels of unconditioned stimuli (UCS) intensity and presented to three levels of unreinforced conditioned stimuli (CS) exposures (extinction phase) in a delay differential conditioning paradigm. The CSs were fear-relevant slides (snakes and spiders) and the UCSs were aversive tones. Analysis did not show a clear incubation effect; instead an increased resistance to extinction of SCR probability in association to the high-UCS and the short unreinforced CS presentation was evident. Findings support partially Eysenck's incubation theory of fear/anxiety.     

Brain asymmetry and human electrodermal conditioning

Two experiments are reviewed that demonstrate effects of brain laterality on human classical conditioning. Pictures of facial emotional expressions were used as conditioned stimuli (CSs) together with shock as unconditioned stimlus (UCS). Bilateral electrodermal responses were recorded as dependent measures. In the first experiment, one group was conditioned to an angry face, and one group to a happy face. During extinction, the face-CSs were presented to the right hemisphere on half of the trials and to the left hemisphere on the other half of the trials. Results showed that the right hemisphere was superior in showing persisting effects of learning, and especially to the angry CS+. In the second experiment, lateralized presentations of the angry and happy faces were made during acquisition, with foveal presentations during extinction. Once again, the angry face elicited greater skin conductance responses (SCRs) during extinction in the group that had this stimulus presented to the right hemisphere during acquisition. It is concluded that emotional conditioning is differentially regulated by the two hemispheres of the brain.     

Brain asymmetry and human electrodermal conditioning

Two experiments are reviewed that demonstrate effects of brain laterality on human classical conditioning. Pictures of facial emotional expressions were used as conditioned stimuli (CSs) together with shock as unconditioned stimulus (UCS). Bilateral electrodermal responses were recorded as dependent measures. In the first experiment, one group was conditioned to an angry face, and one group to a happy face. During extinction, the face-CSs were presented to the right hemisphere on half of the trials and to the left hemisphere on the other half of the trials. Results showed that the right hemisphere was superior in showing persisting effects of learning, and especially to the angry CS+. In the second experiment, lateralized presentations of the angry and happy faces were made during acquisition, with foveal presentations during extinction. Once again, the angry face elicited greater skin conductance responses (SCRs) during extinction in the group that had this stimulus presented to the right hemisphere during acquisition. It is concluded that emotional conditioning is differentially regulated by the two hemispheres of the brain.     

Sex differences and bilateral electrodermal activity

The present study was aimed at replicating the results of a previous work on sex differences and electrodermal asymmetry from our laboratory (Román,et al. 1987). Skin conductance was bilaterally recorded in a sample of 44 dextral volunteers (22 males and 22 females) during a stimulus-free period, and the performance of two tasks (verbal and spatial). Subjects were grouped into two groups of right-hand and left-hand dominance in their electrodermal responses (EDRs) in accordance with their laterality coefficient scores at rest. During the tasks subjects appeareed clearly differentiated by their lateralization in the magnitude and frequency of EDRs independently of gender: right-hand responders showed higher electrodermal activity on their right hand, while left-hand responders showed higher electrodermal activity on their left hand. Sex differences were not observed within each responsiveness pattern. The orientation of phasic electrodermal changes remained constant throughout the different conditions.