Sensation Seeking and Psychophysiological Responses to Auditory Stimulation

This study tested the hypothesis that the orienting response (OR) is one of the biological correlates of sensation seeking. Skin conductance (SC), heart rate (HR), and peripheral vasomotor (VM) activity were recorded while ten 60dB, 1000 Hz, slow-rise-time tones were presented to male subjects with high (N = 16) and low (N = 15) total scores on Form V of the Sensation Seeking Scale (SSS). There were no significant differences between groups in the SC or VM responses to the first (novel) tone or in the rate at which these responses habituated. The HR response to the first tone was deceleration (an OR) for the high SS group (as well as for a high Disinhibition subgroup), while the response of the low SS group (and a low Disinhibition subgroup) included what appeared to be startle components—a short-latency accelerative response that habituated rapidly on subsequent trials. It is suggested that individuals with low sensation seeking tendencies may be unusually prone to startle, and that subsequent research on the biological correlates of sensation seeking should take into account individual differences in the tendency to give orienting, defensive, and startle responses.     

Autonomic Correlates of Depression and Clinical Improvement Following Electroconvulsive Shock Therapy

Electrodermal responses (EDRs) and heart rate (HR) were recorded during a variety of tasks from 20 hospitalized depressed patients before and after a series of electroconvulsive shock treatments (ECTs). The depressed patients, compared to nondepressed controls during the pre-ECT test, exhibited lower skin conductance levels, smaller phasic skin conductance responses with longer latencies, higher tonic HR, and smaller HR changes to stimuli. This response pattern suggests a complex state of “environmental rejection” coupled with “low arousal” in the depressed patients. Certain EDR measures were related to the severity of depressive symptomatology while tonic HR was related to the agitation/retardation symptoms. Patients who subsequently responded well following ECT were more like the controls on certain pre-treatment measures than those who failed to respond favorably. There were little EDR or HR changes following ECT and what changes did occur were unrelated to differences in clinical improvement. It was suggested that, despite temporary clinical improvement following ECT, depressed patients have a chronic affective disorder which is reflected in the EDR and HR measures.     

Dependence of EDR Recovery Times and Other Electrodermal Measures on Scale of Measurement: A Methodological Clarification

Edelberg (1970) and Boucsein and Hoffmann (1979) found shorter recovery times with a constant voltage method as compared with a constant current method. In the present paper it is pointed out that this effect may be due to the use of different scales of measurement rather than to any electrophysiological aspects of the recording procedure. The mathematical relationship between resistance and conductance implies that recovery times are shorter for SCRs than for corresponding SRRs. For demonstration purposes, recovery times were computed from an SR record and compared with those computed from the same record after computerized transformation to SC. Research implications of the demonstrated effect are discussed, and the relevance of measurement scale to two other electrodermal measures, area below the curve and range-corrected amplitude, is pointed out.     

Ambulatory Electrodermal Monitoring: Effects of Ambient Temperature, General Activity, Electrolyte Media, and Length of Recording

The feasibility of long-term monitoring of electrodermal activity (EDA) from freely moving subjects was assessed by examining several confounding variables including epidermal hydration, ambient temperature, and physical activity. EDA was monitored from 12 subjects during a normal working day. A portable 4 channel cassette recorder (Medilog) was employed to record skin conductance, ambient temperature, and arm movements. The effects of epidermal hydration were assessed using different 0.05 KCl electrolyte media. EDA was quantified throughout the day during several 5-min rest periods and subsequent simple reaction time tasks. In order to distinguish between the influence of time of day and electrode/electrolyte aging, an extra pair of fresh electrodes was applied at each measurement period. Significant effects of temperature, electrolyte medium, and time of measurement on several indices of EDA were obtained. The implications of these data for long-term ambulatory EDA monitoring were discussed.     

The Psychological Significance of Task-Induced Tonic Changes in Somatic and Autonomic Activity

Two experiments tested the view that task-induced autonomic-somatic gradient parallelism does exist and that the steeper the physiological gradients, over the course of a task, the more involved the subject and the greater the effort. Thirty-three male subjects performed easy and difficult versions of a continuous reaction time task. In both experiments the difficult task prompted steeper electromyographic (EMG) activity gradients than did the easy version. Scores on heart rate (HR) and skin conductance did not show clear gradients. However, task-dependent effort was positively related to the magnitude of the initial HR acceleration and to the steepness of the EMG gradient. The autonomic-somatic coupling hypothesis of Obrist did not explain the results. Instead, evidence for ventilatory-somatic parallelism was found.     

Response Requirements and Directional Fractionation of Autonomic Responses

Physiological responses were monitored while 27 male Ss were shown a series of 45 colored slides of homicide victims. Nine of the Ss were required to simply look at each slide (Nonraters), 9 were required to push 1 of 7 buttons, after each trial to indicate how disturbing they found the slide to be (Raters). Evidence for directional fractionation of autonomic responses to the slides was obtained for only the Nonraters. Their responses included cardiac deceleration, an increase in skin conductance, digital vasoconstriction, and cephalic vasodilation. The Raters responded with cardiac acceleration, an increase in skin conductance, and both digital and cephalic vasoconstriction. The Raters also showed a larger increase in tonic skin conductance over trials than did the Nonraters. To determine whether the physiological responses of the Raters were influenced by the requirement to make a motor response, 9 other Ss pressed a button after each slide. The physiological responses of these latter Ss were almost identical with those of the Nonraters. The results are consistent with the hypothesis that the requirement to rate the stimuli was associated with appraisal and cognitive elaboration. They also indicate that response requirements can have a profound effect upon autonomic responsivity.     

Getting Individual Differences in Autonomic Reactivity to Work For Instead of Against You: Determining the Dominant "Psychological" Stress Channel on the Basis of a "Biological" Stress Test

The purpose of this study was to develop a procedure to increase the re liability of autonomic measures, such as skin conductance (SC) and heart rate (HR), when assessing negative emotional responding. The strategy was to capitalize on the individual difference factor by determining prior to the start of an experiment each subject's most reactive autonomic channel. To achieve this objective, a “biological” stress test (balloon-burst test) was used. Subjects were then classified by using a median-split, rank-ordered procedure, as high SC responders, high HR responders. high responders in both channels, or low responders in both channels. The generality of the responder-non-responder classification was then assessed to a “psychological” stressor which involved presentations of a fear-eliciting bodily-injury slide. Transfer effects were obtained with those subjects defined as high responders on a given channel displaying greater reactivity on that channel when compared to subjects classified as low responders. The implications of these findings for clinical research were discussed.     

Effects of Length of Training and Amount of Tone Frequency Change on Amplitude of Autonomic Components of the Orienting Response

The present study investigated amplitude of the skin conductance response (SCR), heart rate response (HRR), and linger pulse volume (FPV) response components of the orienting response to a change in lone frequency following habituation training. Experimental subjects received either 5 or 20 presentations of a 1000 Hz, 70 dB training stimulus of 3 sec duration followed by presentation of a test stimulus. Half of these subjects received a test stimulus of 670 Hz (decrease of 250 mels), while for the other half, the test stimulus was a 380 Hz (decrease of 500 mels) tone. Two independent control groups received 6 and 21 presentations of the training stimulus respectively. This resulted in a 3 × 2 factorial design (N = 90). The results indicated that test trial SCR amplitude was significantly larger in experimental groups than in control groups and that larger responses occurred for a change of 500 mels than for one of 250 mels. Experimental groups also displayed significantly larger HRRs than did control groups, but within (he experimental groups, response amplitude was not influenced by amount of change. Length of training had no significant effect on either SCR or HRR amplitude on the test trial. For digital vasoconstriction, experimental groups displayed significantly larger FPV responses than did the control groups only after 2(1 training trials, and response amplitude was not influenced by amount of stimulus change.     

Physiological Correlates of Mental Activity: Eye Movements, Alpha, and Heart Rate During Imagining, Suppression, Concentration, Search, and Choice

Rapid eye movements (REMs), EEG alpha, and tonic heart rate (HR) were measured during 6 types of cognitive tasks—imagining a liked person, suppressing thoughts of the person, searching one's mind for alternative solutions, arithmetic involving little concentration, problems involving high concentration, and choosing a preferred activity. The latter 3 required verbalization, the former 3 did not. Only suppression and search did not differ significantly from each other on at least one physiological variable. Imagining, suppression, and search yielded few REMs, high alpha, and low HR. High concentration yielded many REMs, low alpha, and high HR. Choice yielded many REMs, low alpha, and intermediate HR. Low concentration yielded few REMs, low alpha, and high HR. Suppression produced somewhat less alpha than imagining but did not differ significantly in REMs.     

The Effects of Monetary Incentive and Frustrative Nonreward on Heart Rate and Electrodermal Activity

Further investigation of a recent theoretical model positing the existence of mutually antagonistic appetitive versus aversive motivational systems was conducted by providing monetary incentives for 3 trials and then either with or without warning terminating the incentives for the last 2 trials. Two dependent measures-heart rate and electrodermal activity–were employed to test the predictions that incentives would activate the appetitive system and produce heart rate acceleration, while unsignalled termination of incentives (frustrative nonreward) would activate the aversive system and produce relative electrodermal activity increases. An additional goal was to investigate the effects on heart rate of different magnitudes of incentive per response unit and varying the amount of work per response unit–two ways of achieving different total amounts per trial. The data showed a clear and graded heart rate response to varying the amount of work per response unit. These results were interpreted as consistent with the conclusion that the heart rate response is a function of the amount of incentive per unit of effort. In contrast to the clear effect on heart rate, the incentive manipulations had no observable effect on electrodermal activity. Conversely, electrodermal activity showed a clear response to frustrative nonreward, while heart rate was not affected. These results were interpreted as consistent with the notion of separate motivational systems mediating different behavioral effects.     

Some Antecedents of Directional Fractionation: Effects of "Intake-Rejection," Verbalization Requirements, and Threat of Shock on Heart Rate and Skin Conductance

Following recent contradictory claims in the literature regarding the phenomenon of directional fractionation, the present study was designed to investigate variables related to this differential patterning of autonomic response. Heart rate (HR) and skin conductance (SC) were recorded from 89 male students who either attended to flashing lights or worked a subtraction problem under threat-of-shock or no-shock conditions. Effects of instructions to verbalize later were also investigated. While significant task differences were demonstrated which were consistent with the directional fractionation hypothesis, instructions to verbalize later affected neither HR nor SC. Threat of shock significantly elevated HR during the task only for Ss attending to flashing lights. However, threat of shock significantly raised HR and SC levels immediately after instructions (and preceding the task) when combined with instructions for subtraction. Results were contrary to arousal theory, supportive of Lacey's theory of an “intake-rejection” dimension, and contrary to Campos and Johnson's verbalization findings.     

Face the Beast and Fear the Face: Animal and Social Fears as Prototypes for Evolutionary Analyses of Emotion

This paper applies a functional-evolutionary perspective to fear in the context of encounters with animals and threatening humans. It is argued that animal fear originates in a predatory defense system whose function is to allow animals to avoid and escape predators. Animal stimuli are postulated to be differentially prepared to become learned elicitors of fear within this system. Social fears are viewed as originating in a dominance/submissiveness system. The function of submissiveness is to avert attacks from dominating conspecifics. Signs of dominance paired with aversive outcomes provide for learning fear to specific individuals. Data which in general are interpreted as supportive of this conceptualization are reviewed. To explain the mechanism behind the causal relationships suggested in the evolutionary analysis, an information-processing model is presented and empirically tested. It is argued that responses to evolutionary fear-relevant stimuli can elicit the physiological concomitants of fear after only a very quick, “unconsciousness,’ or preattentive stimulus analysis. Support for this notion is presented from backward masking studies where it is demonstrated that conditioned autonomic responses to fear-relevant stimuli can be elicited even with masked stimuli.     

The Three Arousal Model: Implications of Gray''s Two-Factor Learning Theory for Heart Rate, Electrodermal Activity, and Psychopathy

Gray's two-factor learning theory postulates a behavioral activation system (BAS), a behavioral inhibition system (BIS), and a nonspecific arousal system receiving excitatory inputs from both the BAS and the BIS. The BAS initiates behavior in response to conditioned stimuli for reward (approach) or for relieving nonpunishment (active avoidance). The BIS, which is viewed as an anxiety system, inhibits behavior in response to cues for punishment (passive avoidance) or frustrative nonreward (extinction), and its activity is decreased by the anti-anxiety drugs (alcohol, barbiturates, minor tranquilizers). Thus, the BIS is an arousal system which inhibits rather than energizes behavior. A review of the literature suggests that heart rate (HR) is strongly associated with activity of the BAS. This interpretation subsumes the previous findings of cardiac-somatic coupling, incentive effects on HR, and increased HR in connection with active coping in the face of threat. Electrodermal activity (EDA), on the other hand, increases when there is an activation of the BIS. A consideration of these differing effects on HR and EDA permits a specification of conditions in which these two measures will or will not show directional fractionation. With this theoretical model it is possible to relate the clinical features of psychopathy to the psychophysiological data with the single assumption that primary psychopaths have a deficient BIS. As a result, they show normal approach, active avoidance, and HR, but they suffer from poor passive avoidance and extinction with reduced EDA in response to threatening stimuli.     

Effects of intrinsic pleasantness and goal conduciveness appraisals on somatovisceral responding: Somewhat similar, but not identical

In the emotion literature, appraisals of an event's pleasantness and goal conduciveness are often considered as interchangeable and subsumed under the term valence. Some appraisal theories, however, emphasize that there is a conceptual difference between these two appraisals. With the current study, we investigated whether such a conceptual difference would be reflected in different somatovisceral response profiles for intrinsic pleasantness and goal conduciveness. Participants viewed unpleasant and pleasant pictures (intrinsic pleasantness) and performed either goal conducive (i.e., decreasing the size of unpleasant pictures, increasing the size of pleasant pictures) or goal obstructive (i.e., increasing the size of unpleasant pictures, decreasing the size of pleasant pictures) arm movements. Our data suggest that the two appraisals have somewhat similar, but not identical, response patterns. Thus, our results emphasize the importance of distinguishing between intrinsic pleasantness and goal conduciveness. Moreover, we find evidence that the efferent effects of the two appraisals combine multiplicatively, and that predictability of goal conduciveness may influence the impact of goal conduciveness appraisals on somatovisceral responding.