Voluntary control of human heart rate: Effect on reaction to aversive stimulation: A replication and extension.

In anticipation of receiving painful stimuli, 20 female Ss learned to regulate their heart rate (HR) when provided with meter biofeedback and monetary bonuses for HR changes and instructions to increase or decrease their rate. Voluntary slowing of HR was associated with a relative reduction in perceived aversiveness of the stimuli, particularly in those Ss who scored high on a cardiac-awareness questionnaire (i.e., reported experiencing cardiac reactions to fear situations in daily life). These fingings replicate and extend previous findings by the authors (see record 1974-31631-001) on HR self-regulation, perception of aversive stimulation, and individual differences in cardiac awareness. They also provide further support for the hypothesis that biofeedback training for relevant physiological responses may serve as a behavioral strategy for changing anxiety and fear reactions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Morphine influences on classical aversive conditioned heart rate in rats.

Investigated in 3 experiments the effects of morphine and the morphine antagonist naloxone on the development of a classical aversive heart rate (HR) conditioned response (CR) to a tone conditioned stimulus (CS) paired with an electric shock unconditioned stimulus (US). In Exp I, groups of rats received either 0.25, 5 or 10 mg/kg, sc, of morphine. Three other groups were given 0.1, 5, or 10 mg/kg of naloxone. All morphine groups showed attenuation HR responses to the CS on preconditioning CS-alone trials. During conditioning, the 10-mg/kg morphine group showed a markedly decremented bradycardia CR and tachycardia unconditioned response (UR), whereas the 5-mg/kg morphine group showed a normal CR in combination with a decremented UR. In the Exp II, 1 mg/kg naloxone given after conditioning failed to reverse the CR and UR losses produced by 10 mg/kg of morphine given prior to conditioning. 10 mg/kg of morphine produced only a minor reduction in a HR CR established in a drug-free state, but the tachycardia UR was severely reduced. Exp III showed that 1 mg/kg of naloxone was effective in reversing analgesia induced by 10 mg/kg of morphine. 10 mg/kg dose of morphine interfered with the learning of a HR CR, perhaps principally by reducing the aversive or emotional consequences of the shock US. Direct cardiovascular effects of morphine seemed to interfere with the performance of the tachycardia UR, but not with the performance of the bradycardia CR. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of respiration on heart rate in an aversive classical conditioning situation.

Previous research has attempted to assess respiratory influences on the cardiac response in anticipation of shock. These studies have utilized either control of rate of respiration, sustained inhalation or exhalation, control of amplitude of respiration, or some combination of these. In the present study, 30 18-25 yr. Old male undergraduate ss inhaled at the start of each trial, held their breath, exhaled during a 4-sec tone, and then refrained from breathing in again until they received an electric shock. Thus, each trial corresponded to 1 breath cycle. Cs-ucs interval and duration of breath holding were varied orthogonally. The 3 major findings were: (a) a reliable, large magnitude (20 bpm) deceleration followed the inhalation at the start of each trial; (b) the acceleratory component of the cardiac response in anticipation of shock increased with cs-ucs pairings, and therefore could not be considered an orienting reflex; and (c) the biphasic form of the cardiac response occurred over an 8-10 sec. Period, regardless of cs-ucs interval, and appeared to be "locked" to the cs rather than to the ucs. (french summary) (16 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Some consequences of the reaction to an aversive event.

In a free-responding situation an animal that merely reacts to an aversive event may appear to anticipate that event. To illustrate this problem, one of the typical reactions of a rat to a brief electric shock is considered. Although electric shock usually reduces the overall response rate, a given shock often leads to a burst of responses. The simulated behavior of such purely reactive Ss resembles the actual behavior of rats under conditions of nondiscriminative avoidance and punishment. Similar problems arise in other learning situations, and the yoked design is shown to be an inappropriate control, even without the assumption of individual differences. Several tests are described that distinguish the anticipation of an event from the reaction to an event. (17 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Multiple somatic measures and heart rate during classical aversive conditioning in the cat.

In 2 experiments, a total of 9 freely moving cats were subjected to classical aversive conditioning under either a delay or a trace paradigm using a tone conditioned stimulus (CS) and a shock unconditioned stimulus (UCS). During a 7- or 9-sec CS-UCS interval, heart rate (HR) decelerated and concomitantly, general activity, neural activity in the pyramidal motor system, respiration amplitude, and neck muscle electromyogram (EMG) decreased. General activity and pyramidal activity were more related to HR than were respiration and EMG. The close correspondence between HR and the various measures of somatic activity are interpreted as showing the dependence of HR change on the metabolic demands of the organism. The concomitance demonstrated between HR change and somatic change provides further evidence against HR change as a direct index of emotional or motivational processes. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Locus of control and the response to aversive events.

Reports on a previous series of studies by the author and his colleagues which used locus of control as an independent variable and provided evidence in support of data from situationally contrived studies of perceived control. It is concluded that the impact of stressors seems to be diminished in situations in which participants can exercise some degree of control. Likewise, persons assessed as holding internal control expectancies seem to be better able to withstand the assault of stressors than externals. Fatalistic persons seem to have less recourse to cognitions that can lessen the impact of stressful events. (French abstract) (23 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Acoustic stimulation in hypoxic-ischemic encephalopathy: heart rate analysis

The object of this study was to analyze the cortical thickness (Ct.Th) of the ventral and dorsal shell of the vertebral bodies throughout the human spine in aging and in osteoporosis. Therefore, the complete front column of the spine of 26 autopsy cases (aged 17-90, mean 42 years) without diseases affecting the skeleton and of 11 cases (aged 58-92, mean 77 years) with proven osteoporosis were removed. A sagittal segment prepared through the center of all vertebral bodies was undecalcified, embedded in plastic, ground to a 1 mm thick block, and stained using a modification of the von Kossa method. The analysis included the measurement of the mean cortical thickness of both the ventral and dorsal shell, respectively (from the third cervical to the fifth lumbar vertebral body). The qualitative investigation of the structure of the cortical ring completed the analysis. The presented data revealed a biphasic curve for both the ventral and dorsal shell, skeletally intact with high values of the cortical thickness in the cervical spine (285 microm), and a decrease in the thoracic (244 microm) and an increase in the lumbar spine (290 microm). The mean thickness of the ventral shell is in general greater than the thickness of the dorsal shell in both skeletally normal and osteoporotic cases. The cortical thickness of the spine showed no gender-specific differences (p = NS). There was a slight decrease of the cortical thickness with aging; however, this decrease and the correlation of cortical thickness to age was only significant below vertebral body T8 (r = 0.225-0.574; p(r) < 0.05-0.005). Most interestingly, however, osteoporosis presents itself with a highly significant loss of cortical thickness throughout the whole spine. This decrease of cortical thickness was more marked in the dorsal shell (p < 0.05) than in the ventral shell (ventral from C3 to T6 [p < 0.05] below T6 [p = NS]). We therefore conclude that in osteoporosis the loss of spinal bone mass is not only a loss of trabecular structure but also a loss of cortical thickness. Furthermore, these results may explain the development of regions of least resistance within the spine in aging and the clustering of osteoporotic fractures in the lower thoracic and lumbar spine.     

The effect of aversive stimuli on reaction time in schizophrenia.

"… the experiment was to assess the motivational role of aversive stimuli in modifying the performance of normal and… schizophrenic… males… [on] a visual reaction time task… . During… [one] series Ss responded under… experimental conditions… [part of which] involved the use of intense noise as an aversive stimulus. None of the experimental conditions appreciably altered the performance of normal Ss. However, schizophrenic Ss performing under… [conditions involving noise] displayed greater improvement than control Ss." 22 refs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Voluntary control of hypothalamic temperature.

Reports 3 experiments in which 7 male Sprague-Dawley rats were given direct voluntary control of hypothalamic temperature by having their responses produce temperature changes in the water perfusing their hypothalamic thermodes. When heat stressed, Ss worked vigorously for hypothalamic cooling; brain cooling is thus a reward for a warm animal. Exp. II compared rates of responding for brain cooling and external cooling and found that, under a given set of heat-stress conditions, the rates of responding for internal and external cooling were the same. Exp. III determined whether reductions in hypothalamic temperature caused temperature changes at any other place in the body besides the one in the anterior hypothalamic-preoptic area; however, no other area was found. Results indicate that an interoceptive stimulus is a rewarding event and its effectiveness as a reward is comparable to that of an exteroceptive stimulus. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Style of adaptation to perceived aversive maternal stimulation and selective attention to evaluative cues.

Tested the hypothesis that given sustained exposure to aversive maternal control, the male child tends to adapt by 1 of 2 coping styles: (a) a closed style involving social avoidance and narrowed attention to evaluative cues, and (b) an open style embracing manipulative social approach and heightened attention to evaluative cues. 49 experimentally defined closed style and open style aversive-control male undergraduates were compared in their ability to recognize briefly exposed evaluative words. The closed style group correctly identified fewer words than the open style group as predicted. Incorrectly identified words reflected a tendency toward evaluative self-enhancement for both groups. Control comparisons revealed neither difference. Some promising relations between coping styles, breadth of attention to evaluative cues, and paranoid behavior are noted. (16 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of alcohol administration on psychophysiological and subjective-emotional responses to aversive stimulation in anxiety-sensitive women.

Examined the effects of anxiety-sensitivity (AS) levels, and 1.00 ml/kg alcohol, on autonomic and subjective-emotional responses to aversive stimulation (i.e., noise bursts). Ss were 30 university women divided into 3 AS groups (high, moderate, and low), on the basis of Anxiety Sensitivity Index (ASI) scores. When sober, high-AS women provided higher emotional arousal ratings while anticipating the noise bursts than did low-AS women. Alcohol dampened the noise burst-anticipation ratings, particularly in the high-AS group. ASI scores were positively correlated with degree of sober skin conductance level (SCL) reactivity and with degree of alcohol dampening of SCL reactivity. Thus, high-AS women may use alcohol to normalize their anticipatory emotional and electrodermal overreactivity to threat. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Personal control over aversive stimuli and its relationship to stress.

Reviews experimental research relating types of personal control to the experience of stress. 3 main types of personal control may be distinguished: (a) behavioral (direct action on the environment), (b) cognitive (the interpretation of events), and (c) decisional (having a choice among alternative courses of action). Each type of control is related to stress in a complex fashion, sometimes increasing it, sometimes reducing it, and sometimes having no influence at all. It may be generally said that the relationship of personal control to stress is primarily a function of the meaning of the control response for the individual, i.e., the stress-inducing or stress-reducing properties of personal control depend upon the nature of the response and the context in which it is embedded and not just upon its effectiveness in preventing or mitigating the impact of a potentially harmful stimulus. (66 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The concept of uncertainty in animal experiments using aversive stimulation.

Reviews rat experiments using aversive stimuli in which some element of uncertainty was involved. Nine cases of conditions that produce uncertainty are described, and relevant experimental facts are examined. Rats were found to prefer situations involving certainty to those involving uncertainty, and the rats' basal rate of responding was found to be less in suppression situations involving uncertainty about aversive environmental events than in those involving relative certainty. Results are obtained when the aversive stimuli the rats received were physically matched in quantity among the conditions compared. Results are discussed with reference to the safety signal, preparatory response, time allocation, contextual fear, and information hypotheses. It is concluded that the function of the concept of uncertainty is to organize a class of studies that are otherwise unrelated. (59 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Style of adaptation to perceived aversive material control and internal scanning behavior.

Tested the proposal that comparability in life-styles exists between normal college males who have adopted closed and open styles of coping with aversive maternal control (i.e., perceived high control, low nurturance) and the life-styles of process and reactive schizophrenics. Breadth of internal scanning behavior, defined in terms of the availability of alternate word meanings, was studied with the expectation that closed-style males would be broader internal scanners in keeping with the adaptive-style model and with the limited evidence on process-reactive schizophrenics. 56 white male undergraduates completed the Parental Attitude Research Instrument, A. Heilbrun's parent-child interaction rating scales, A. Willner's unusual meanings vocabulary test, and the Stroop Color-Word Test. Closed-style males were superior to open-style males on a test of nondominant word namings and also provided more remote free word associations. No differences were found on a word-meaning test not requiring extended meanings. (24 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Autonomic control of heart rate during physical exercise and fractal dimension of heart rate variability

The objectives of the present study were to investigate autonomic nervous system influence on heart rate during physical exercise and to examine the relationship between the fractal component in heart rate variability (HRV) and the system's response. Ten subjects performed incremental exercise on a cycle ergometer, consisting of a 5-min warm-up period followed by a ramp protocol, with work rate increasing at a rate of 2.0 W/min until exhaustion. During exercise, alveolar gas exchange, plasma norepinephrine (NE) and epinephrine (E) responses, and beat-to-beat HRV were monitored. HRV data were analyzed by "coarse-graining spectral analysis" (Y. Yamamoto and R. L. Hughson. J. Appl. Physiol. 71: 1143-1150, 1991) to break down their total power (Pt) into harmonic and nonharmonic (fractal) components. The harmonic component was further divided into low-frequency (0.0-0.15 Hz) and high-frequency (0.15-0.8 Hz) components, from which low-frequency and high-frequency power (Pl and Ph, respectively) were calculated. Parasympathetic (PNS) and sympathetic (SNS) nervous system activity indicators were evaluated by Ph/Pt and Pl/Ph, respectively. From the fractal component, the fractal dimension (DF) and the spectral exponent (beta) were calculated. The PNS indicator decreased significantly (P < 0.05) when exercise intensity exceeded 50% of peak oxygen uptake (VO2 peak). Conversely, the SNS indicator initially increased at 50-60% VO2peak (P < 0.05) and further increased significantly (P < 0.05) at > 60% VO2peak when there were also more pronounced increases in NE and E.(ABSTRACT TRUNCATED AT 250 WORDS)     

Reactivity of skin blood flow and heart rate to external thermal stimulation in anencephaly

Stromal endometriosis refers to the presence of endometriotic stroma without the presence of endometrial glands. We report a case in the uterine cervix in which the diagnosis of Kaposi's sarcoma was considered before being discounted on histological and immunohistochemical grounds.     

Pharmacologic control of heart rate in atrial fibrillation

Atrial fibrillation is associated with a resting heart rate in excess of age-matched subjects in sinus rhythm, and there is an additional steep rise in rate during exertion. This article reviews the factors responsible for this tachycardia, the pharmacologic agents commonly used for heart rate control, and the effects of atrial antiarrhythmic agents on the heart rate during paroxysmal atrial fibrillation.     

Sensory deprivation and autocontrolled aversive stimulation in the reduction of snake avoidance.

Selected 30 female snake-aversive college students based on responses to the Fear Survey Schedule. Ss in Group 1 (n = 10) underwent 5 hrs of sensory deprivation. Periodically during 3 subsequent hours, they could initiate the presentation of slides which showed snakes in varying degrees of realism. 5 of these Ss saw the slides in random order, and 5 saw them in order of increasing verisimilitude. 10 other Ss could do the same without previous deprivation; 10 more, without deprivation, saw the slides with frequencies yoked to an S in Group 1. Deprived Ss evidenced significantly more fear reduction, both on approach behavior to a live snake and on a self-report measure, than the other 2 groups. Random presentations evoked more viewing responses, and more fear reduction in deprived Ss, than hierarchical order. Results suggest that sensory deprivation may be a useful tool in behavior modification contexts. (French summary) (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)