Heart Rate and Blink Rate Responses During Mental Arithmetic With and Without Continuous Verbalization of Results

The purpose of this study was to investigate the effect of speech motor activity during the performance of mental arithmetic tasks on the cardiac-eyelid motor relationship. In 29 subjects, heart rate and blink rate responses were analyzed during the performance of tasks with and without continuous verbalization of results. Heart rate and blink rate were differentially affected by the experimental conditions. Significant heart rate increases were observed under both test conditions with responses being largest during verbalization. Significant blink rate increases, in contrast, occurred only when verbalization of results was required. The interactions between verbalization vs no-verbalization and both the order of tasks and task type were significant only for heart rate. Furthermore, neither between-subject nor within-subject correlations provided evidence for a close positive relationship between heart rate and blink rate under either the verbalization or the no-verbalization condition. The present results support the suggestion that heart rate and concomitant somatic activity may be “uncoupled” under certain stimulus conditions.     

Alterations in Cardiac Contractility During Classical Aversive Conditioning in Dogs: Methodological and Theoretical Implications

An investigation of sympathetic influences on the heart was undertaken in dogs using classical aversive conditioning procedures. For this purpose, heart rate and cardiac contractile changes were measured, the latter using techniques assessing the rate of change or slope at which either the muscles of the left ventricle contract, or blood is accelerated in the ascending aorta, or the pulse pressure wave ascends from diastole to systole. Sympathetic influences were found to be more clearly manifest in contractile rather than heart rate changes as indicated by the greater attenuating influence of beta-adrenergic blockade on anticipatory and unconditioned responses. Anticipatory sympathetic influences on the heart were commonly acute, becoming minimal upon repeated exposure to the aversive procedures. The rate of change or slope measures appear to detect sensitively extrinsic sympathetic influences on contractility. They are minimally influenced by intrinsic effects on contractility such as heart rate as well as non-contractile events such as diastolic blood pressure. The slope of the ascending limb of the pulse pressure wave appears to offer a means of assessing contractility in human Ss.     

The Cardiac-Somatic Conditioned Relationship in Cats With Mesencephalic Lesions

The problem of dependence or independence of conditioned autonomic-somatic responses has deep implications for learning theories and psychosomatic diseases. Recently, Miller (1969) has postulated independent mechanisms for both responses. On the other hand, Obrist et al. (1970) look at these processes in normal subjects as dependently interrelated. In this work, the conditioned heart rate (CHR) was studied during formation of avoidance conditioning in normal cats and in cats with lesions in mesencephalic reticular formation. The results tend to favor the hypothesis of independence of both processes.     

Changes in Cardiac Refractory Period During Signalled Shock Avoidance in Dogs

The effect of training during an aversive conditioning schedule on the ventricular effective refractory period (ERP) and the occurrence of repetitive extrasystoles (RE) was investigated in 11 dogs. The ERP was decreased significantly at avoidance onset during the first 5 days of the experiment. but remained unaltered during the second 5 days of testing. The changes in ERP were most pronounced on the first day. REs were observed most during avoidance in the animal with the greatest decrease in ERP but inconsistently in other animals. The potential use of aversive Training procedures to study the role of neural factors in cardiac arrhythmias is discussed.     

Coronary Risk and Coping with Aversive Stimuli

In this research the effects of predictability of an aversive stimulus on GSR amplitude and the cardiac anticipation of that stimulus were investigated as a function of coronary risk. Thirty male infarction patients, 16 controls with high- and 18 controls with low-infarction risk, received 10 aversive auditory stimuli, 5 of which were preceded by a warning signal. Predictability reduced GSR amplitude in all groups but significantly more in the low-risk group as compared with the patients and the high-risk group. Cardiac anticipatory acceleration was significantly stronger in the low risk group than in the other two groups. These results were discussed in terms of the effects of anxiety and attention on coping with aversive stimuli.     

Cardiac Cycle Time Effects on Performance, Phasic Cardiac Responses, and Their Intercorrelation in Choice Reaction Time

Temporal relationships between phasic cardiac responses and choice reaction time (RT) performance were studied in 8 human volunteers using a speed-accuracy tradeoff design. “Cardiac cycle time” was varied by presenting stimuli at either the R wave of the electrocardiogram or 350 msec afterward. The speed and accuracy of choice RT performance were systematically manipulated by rewarding subjects for responding as close as possible to five different RT targets (150, 200, 250, 300, and 350 msec). The magnitude of both the cardiac deceleration which preceded stimulus onset and the cardiac acceleration which followed the response varied systematically with RT; both anticipatory deceleration and accelerative recovery were larger for faster RTs. More importantly, the timing of the shift from anticipatory deceleration to accelerative recovery varied systematically as a function of both cardiac cycle time and RT. Correlations between performance and cardiac interbeat intervals (IBIs) before, during, and after the RT were uniformly low, but showed consistent variation as a function of temporal proximity of the IBI to the stimulus. An hypothesis which relates timing of task completion, timing of vagal inhibition, and phasic cardiac responses was proposed to account for the timing of the shift from anticipatory deceleration to accelerative recovery.     

Beat-by-Beat Cardiac Responses in Normals and Schizophrenics to Events Varying in Conditional Probability

Anticipatory cardiac deceleration and poststimulus acceleration were studied in schizophrenic inpatients and controls during performance of a counting task. Reduced cardiac responding has been reported for schizophrenic patients for paradigms using relatively long intertrial intervals. During a relatively fast rate of stimulus presentation (3-s interstimulus interval), changes in cardiac interbeat interval were measured in 20 inpatient male chronic schizophrenics and 18 control volunteers. Subjects counted an infrequent tone which was always followed by at least one frequent tone. Control subjects showed significant anticipatory cardiac deceleration preceding the unpredictable tones, whereas patients did not show a differential cardiac deceleration. Control subjects showed poststimulus acceleration that was inversely proportional to the conditional probability of events, whereas patients exhibited greatly reduced poststimulus acceleration; patterns for both groups resembled findings previously observed for event-related potential and pupillary dilation data. Analysis of cardiac cycle time indicated significant variation in primary bradycardia associated with the delay between stimuli and immediately preceding R-waves in controls (replicating Lacey & Lacey, 1980), with only an immediate bradycardia at stimulus reception for patients regardless of cardiac cycle time. The data reinforce the notion that the manner in which information is used by schizophrenics, as reflected by cardiac responsivity, differs both quantitatively and qualitatively from that of controls.     

Aversive Pavlovian conditioning in psychopaths: peripheral and central correlates

Differential aversive Pavlovian conditioning with a foul odor as unconditioned stimulus (US) and neutral faces as conditioned stimuli (CS) was compared between 9 noncriminal psychopaths as defined by the Hare Psychopathy Checklist Revised and 12 healthy controls. Event-related potentials (ERP), heart rate, skin conductance response, corrugator EMG, and startle response potentiation as well as valence, arousal, and contingency of the CS were assessed. Whereas the healthy controls (HC) showed significant CS +/CS- differentiation, the psychopaths (PP) failed to exhibit a conditioned response although unconditioned responses were comparable between the groups. N100, P200, and P300 to the CSs revealed that psychopaths were not deficient in information processing and showed even better anticipatory responding than the HC group indicated by the terminal contingent negative variation (tCNV), that lacked, however, CS+ and CS- differentiation. These data indicate a deficit in association formation in psychopaths that may be related to deficient interaction of limbic-subcortical and cortical structures.     

Aversive noise effects on performance and thalamocortical responsiveness in cats

The effects of noise bursts (115dBA) on runway performance, emotional behaviors, and visual thalamocortical responsiveness were examined in five cats. Aversion thresholds for noise were subsequently determined in a shuttle box preference test. For three animals the noise was aversive, produced a disruption of runway performance and escape behaviors, and significantly attenuated the intracortical evoked potential (EP) components produced by stimulation of the optic tract. Examination of videotapes taken during noise stimulation indicated that the EP returned to preaversion amplitudes simultaneously with behavioral habituation. The EP intracortical components remained within control levels for animals for whom the noise was not aversive. The aversion effects were concluded to be produced by high arousal activating cortical inhibition. The subsequent behavioral and electrophysiological habituation may involve negative feedback modulation of reticular activity, whereupon cortical functioning returns to preaversion levels.     

Autonomic Activity During Anticipation of An Aversive Tone in Noninstitutionalized Sociopaths

Fifteen noninstitutionalized, compulsive-gambler sociopaths and 15 controls were run in a modification of Hare's (1965b) gradient of fear paradigm. Both heart rate and bilateral skin conductance were averaged during 8 3-sec intervals prior to the presentation of a 95dB tone. The controls showed both earlier and larger electrodermal anticipation of the tone than the sociopaths. For both groups of subjects, electrodermal anticipation of the tone began sooner and was larger in amplitude in the right hand than in the left hand. There were no significant heart rate differences between the two groups of subjects.     

Effects of Control Over Aversive Stimulation and Type A Behavior on Cardiovascular and Plasma Catecholamine Responses

Cardiovascular, plasma catecholamine, and behavioral effects of control over aversive events were studied in 87 Type A and B male adults. Subjects performed a choice reaction time (RT) task during which they received loud noise bursts and/or electric shocks on designated trials. About half of the cases were told they could avoid noise and shock by attaining a predetermined criterion of RT speed (Contingency). The remaining half were instructed that noxious stimulation would be delivered randomly, irrespective of their performance (No Contingency). Half of the cases in each treatment were exposed to high frequency of aversive stimulation (High FAS), whereas the remaining half received low frequency of such stimulation (Low FAS). Within Contingency, High and Low FAS were designed to signify failure and success, respectively. Aversive stimulation in No Contingency was gratuitous and, therefore, did not convey information about performance. Relative to No Contingency, the Contingency treatment induced greater increases in RT speed, systolic and diastolic blood pressure, and plasma epinephrine. Differential FAS did not potentiate these differences. It also was found that the Type A subjects had higher systolic blood pressure and heart rate responses than Type B's. The prediction that Contingency (particularly with High FAS) would elicit greater physiologic and behavioral hyperresponsiveness in A's than B's received some support in the data for RT speed and plasma NE. Findings were discussed in terms of sympathetic activation of hemodynamic changes under conditions of active coping. Consideration was given to the role of the sympathetic nervous system and Type A behavior in cardiovascular disease.     

Tone Intensity and Rise-Decay Time Effects on Cardiac Responses During Sleep

If the prolonged orienting response, reflected in monophasic cardiac deceleration, indicates attention to stimulus inputs, it should not be easy to evoke the response during sleep. Two experiments confirmed and extended previous work showing that the heart rate response in sleep is primarily accelerative. Acceleration occurred with low intensity. 1000 Hz tones of gradual onset and even to tone offsets when either tone onsets or offsets also elicited a K-Complex. In the absense of a K-complex, there were no significant or consistent changes. Since the accelerative component was present on the first trial, habituation could not account for its appearance. It was concluded that the sleep response probably does not reflect an orienting response.     

Affective, Behavioral, and Avoidance Responses on the Visual Cliff: Effects of Crawling Onset Age, Crawling Experience, and Testing Age

Two visual cliff experiments with human infants are reported that were designed to determine relationships among cardiac responses, avoidance and other behavioral responses, and developmental factors. The developmental factors considered were age at crawling onset, age at testing, and amount of crawling experience. In Experiment 1, infants were given either 30 or 60 days of crawling experience following crawling onset. In Experiment 2, infants were tested at either 9 or 12 months of age and crawling onset age was recorded. Infants were tested using a crawling avoidance procedure and the placing procedure that has been established for heart rate responses. Crawling onset age was the best predictor of avoidance behavior. Heart rate response was also a significant predictor of visual cliff avoidance, and was found to be related to testing age, especially for late crawlers. Looking down behavior was also found to distinguish crawling avoidance and crossing of the deep side of the cliff apparatus. These results, it is argued, suggest that fear is not the primary determinant of avoidance behavior on the visual cliff, but does contribute to avoidance at later ages.     

An Attempt to Elk it Cardiac Orienting and Defense Responses in the Newborn to Two Types of Facial Stimulation

Cardiac and behavioral reactivity of the human newborn to facial stimulation eliciting approach and escape responses were compared in order to test the distinction between cardiac orienting and defensive reactions. Each infant received 8 trials each of check stimulation (stroking near the mouth) and ear stimulation (pinch on the ear lobe). HR response to both tactile stimuli were accelerations of different amplitude when motor responses were also present. When no overt behavioral response was observed, stroking on the check elicited cardiac deceleration while ear stimulation again elicited acceleration. Thus, cardiac orienting was demonstrated in newborns when a rooting stimulus was presented that did not elicit overt head turning. The HR response to ear stimulation on trials unaccompanied by observed movements was a larger acceleration than to cheek stimulation when movement was present. This finding suggests that movement itself does not produce the observed HR increase, but rather that central processing of the signal value of the stimulus determines both overt and cardiac responding.     

Psychopathy and Physiological Activity During Anticipation of an Aversive Stimulus in a Distraction Paradigm

Two investigators independently rated 51 white, male prison inmates on a 7-point psychopathy scale (interrater reliability = .89). The combined ratings were used to divide the inmates into low (1), medium (M). and high (H) psychopathy groups of 17 subjects each. Following a sample trial, each inmate was given two trials in which he could choose how to spend his time during a 5–6 min wait for an aversive stimulus (120dB tone). Three choices were available: 1) continuous white noise, 2) a recording of a nightclub comedian, or 3) a continuous tone that changed in frequency 10 sec before delivery of the aversive stimulus. The aversive stimulus could be avoided on one trial but not on I he other (the order was counterbalanced). When the aversive stimulus was unavoidable (Trial UA), 46 (90.2%) of the inmates spent all or most of their time listening to the comedian, i.e., they adopted a “nonvigilant” strategy, while 38 (74.5%) adopted this strategy when the aversive stimulus was avoidable (Trial A). There were no group differences in the type of strategy used on either trial, or in the physiological responses given by the nonvigilant subjects on Trial UA. Group H tended to give smaller electrodermal responses and a larger increase in HR in anticipation of the sample tone than did Group L, a pattern that is consistent with previous research using classical conditioning or “count down” procedures. On Trial A the nonvigilant subjects in Group H showed a significantly smaller increase in nonspecific skin conductance activity than did Group L. It is suggested that making use of distraction when an aversive stimulus is avoidable results in less conflict and heightened emotional arousal in psychopaths than in other inmates. Some speculations on how psychopaths cope with threat are offered.     

Fearfulness and Startle Potentiation during Aversive Visual Stimuli

Recent experimental research suggests an association between negative affect and potentiation of the human startle reflex, as well as enhancement of this effect among fearful compared to low fear subjects. In the present study, 32 undergraduates were selected for high or low total Fear Survey Schedule scores. Acoustic startle probes were presented while subjects received warned presentations of aversive and neutral photographic slides. High fear but not low fear subjects showed potentiated short-latency cardiac acceleration and blink magnitude, and reduced blink latency, during aversive compared to neutral slides. These results support the hypothesis that affective modulation of startle is enhanced among high fear compared to low fear subjects. Considered in the context of prior findings, the results suggest that this individual difference effect generalizes across psychophysiological components of the startle reflex and diverse procedures for manipulating affect.     

Cardiac Responses Associated with "Yoked-Chair" Shock Avoidance in Squirrel Monkeys

While functional cardiac changes and myocardial pathology have been associated with shock avoidance, whether these effects arc due to shock alone or other aspects of the avoidance situation has not been determined. With 6 groups of “yoked-chair” squirrel monkeys. electrocadiogram, blood pressure, and myocardial pathology were studied. Each avoidance monkey was paired with a yoked monkey which could not cope with shock and received each delivered to the avoidance monkey. The effect of this stress was observed in 5 of 6 yoked monkeys u physical deterioration and severe bradycardia with ventricular arrest, but no significant myocardial necrology. With one exception, paired avoidance monkeys showed no effect of stress. Since previous research has shown that the avoidance situation induces a sympathetic activation which is manifested as myofibrillar degeneration and the present in experiment demonulraled that the yoked situation elicits a parasympathetic-like response and bradycardia with ventricular arrests. cardiac response to the stress of shock avoidance varies depending on whether it occurred in the avoidance or yoked situation.     

Cardiac and Metabolic Responses to “Space Invaders”: An Instance of Metabolically-Exaggerated Cardiac Adjustment?

Heart rate, plus various ventilatory and metabolic indices, were monitored while 24 male subjects played a computer game of the “space invaders” type and during a control condition, in which analogous but ineffective actions were requested and the game proceeded automatically. Relative to baseline, subjects showed much larger increases in heart rate during “space invaders” than during the control condition. However, oxygen consumption, carbon dioxide production, respiratory rate and volume also increased more. While the absolute magnitude of metabolic differences between conditions could be regarded as modest relative to heart rate differences, given the effective range of variations possible for each parameter, the existence of highly significant differences in oxygen consumption and carbon dioxide production militates against assertions of overall cardiac-metabolic independence during “space invaders.” Nevertheless, analysis of individual differences in heart rate reactivity would seem to provide some evidence of metabolically-unjustified heart rate changes during “space invaders.” High heart rate reactors during “space invaders” did not differ from low reactors in either oxygen consumption or carbon dioxide production. In addition, this relatively high heart rate reactivity was specific to the “space invaders” condition; high and low heart rate reactors displayed no differences in heart rate, or in any other physiological measure, during the control condition or during baseline.     

Hemodynamic Changes as a Function of Classical Aversive Conditioning in Human Subjects

Eleven subjects underwent a discriminative classical aversive conditioning paradigm while heart rate, stroke index, and hence cardiac index were continuously monitored. Ten out of 11 subjects showed heart rate decreases to the conditioned stimulus at the time of shock onset. This decrease in rate did not change other hemodynamic parameters. The hemodynamic response to the unconditioned stimulus was an increase in heart rate and cardiac index even though stroke index decreased. These results suggest that the conditioned heart rate changes in human heart rate conditioning are too small to alter other hemodynamic variables.     

Cardiac and Metabolic Activity in Mild Hypertensive and Normotensive Subjects

Heart rate, respiration, and metabolic activity were monitored at rest and during the mental challenge of a video game in 22 mild hypertensive and 53 normotensive young men. Subjects also completed the Eysenck Personality Questionnaire and the Jenkins Activity Survey. The mild hypertensive subjects displayed higher resting heart rates than the normotensives and larger magnitude heart rate increases to the video game. Although groups did not differ in resting respiratory activity, the metabolic rates tended to be higher in the mild hypertensives and they showed reliably greater increases in oxygen consumption and carbon dioxide production during mental challenge. These data were subjected to a variety of interpretations. However, in the absence of psychophysiological assessment during physical exertion, and without direct measurement of cardiao output and arteriovenous oxygen differences, the present results did not permit a choice to be made between rival explanations, and they certainly cannot discount the hypothesis that some borderline hypertensives display excessive cardiac activity and tissue overperfusion during stress. The personality measures did not differentiate groups. However, correlational analyses within each group revealed that whereas systolic blood pressure was positively and significantly related to neuroticism in the mild hypertensive group, for the normotensive subjects the direction of correlation was reversed. In addition, scores on the Jenkins Activity Survey correlated positively with heart rate reactivity to the video game for the mild hypertensives, but not for the normotensives.