Biomedical subjects

J T Cacioppo

Publications and source records attributed to J T Cacioppo.

At least 55 records · Page 3Linked to original sources

PubMed1994

Social neuroscience: autonomic, neuroendocrine, and immune responses to stress.

The immune system is influenced by central nervous system processes that are shaped by social and psychological factors. Considerations of social factors, intrapersonal process, and autonomic psychophysiology therefore may contribute to a fuller understanding of both immune and brain function. Research reviewed here (a) examines the socioemotional factors that contribute to, or moderate, responses to brief and chronic stressors, (b) determines whether or not stable individual differences in heart rate reactivity predict neuroendocrine and immune responses to a brief psychological stressor and to an influenza virus vaccine, and (c) investigates the autonomic origins of individual differences in low and high heart rate reactivity and their relationship to neuroendocrine and immune responses to chronic and acute stressors. Among our findings are: (a) acute psychological stressors activate the sympathetic adrenomedullary system across individuals and affect immune function; and (b) individuals characterized by high sympathetic cardiac reactivity to acute psychological stressors also show a relative activation of the hypothalamic pituitary adrenocortical system and altered immune function.

Arousal↗

PubMed1994

Origins of baseline variance and the Law of Initial Values.

The Law of Initial Value (LIV) asserts that the magnitude of a phasic psychophysiological response is dependent on the initial baseline level. Although results in accord with the LIV are often observed, exceptions are frequent, especially for between-subjects analyses. A general assumption in studies of the LIV is that a given baseline difference is equivalent regardless of its functional origin. The present study examined the relationships between basal heart period variance, arising from alternate sources, and the magnitude of the chronotropic response to a speech stressor. Results reveal that baseline differences due to orthostatic manipulations, which are known to be largely of autonomic origin, yielded larger LIV effects than did individual differences in basal heart period, which include a significant nonautonomic component. The minimal LIV-like effects of baseline differences associated with non-autonomic factors, relative to variations in autonomic control, may contribute to the inconsistent appearance of between-subjects LIV effects.

Adolescent↗

PubMed1994

The effects of an acute psychological stressor on cardiovascular, endocrine, and cellular immune response: a prospective study of individuals high and low in heart rate reactivity.

High and low reactors were preselected on the basis of their heart rate reactivity to a speech stressor in a prescreening session. In the main study, subjects were exposed to a mental arithmetic plus noise stressor. Cardiovascular activity was recorded during baseline and stressor, and blood was drawn prior to and following the stressor for endocrine and immune assays. Results revealed that the stressor decreased the blastogenic response to concanavalin A and increased natural killer cell numbers and cytotoxicity, absolute numbers of CD8+ T-lymphocytes, norepinephrine and epinephrine levels, heart rate, and blood pressure responses. In addition, cortisol and natural killer cell cytotoxicity responses to the stressor differentiated individuals high versus low in heart rate reactivity. These results suggest that the interactions among the autonomic nervous system, endocrine system, and immune system are not only amenable to psychophysiological analysis but that such analyses may play an important role in illuminating underlying mechanisms.

Adolescent↗

PubMed1994

Autonomic cardiac control. I. Estimation and validation from pharmacological blockades.

Pharmacological blockades have been used to estimate the relative contributions of the autonomic branches to cardiac chronotropic control. Systematic biases in these estimates, however, can arise from both methodological and physiological factors. Selective blockades can be interpreted by two inferential models, and a single blockade condition can yield estimates of autonomic control for both autonomic branches. The residual autonomic control of the heart after blockade of a single division provides an index of the functional contribution of the unblocked branch. In contrast, the change in chronotropic state of the heart after blockade of the same division reflects the subtractive loss of that branch and thus provides an index of the normal contribution of the blocked branch. We demonstrate that the systematic biases that can arise in blockade studies introduce distortions of the subtractive and residual estimates that are of equal magnitude but opposite sign. Consequently, the discrepancy between the subtractive- and residual-model estimates provides a measure of bias in blockade studies and permits the derivation of validity indices that can facilitate interpretations of blockade data.

Adrenergic Antagonists↗

PubMed1994

Autonomic cardiac control. II. Noninvasive indices and basal response as revealed by autonomic blockades.

Heart period, systolic time intervals, low and high frequency heart period variability, blood pressure, and respiration were measured in female subjects under three drug conditions (saline, atropine sulfate, metoprolol) while sitting and standing on three consecutive days. Following preinfusion baseline recordings, saline, metoprolol (14 mg), or atropine sulfate (2 mg) was infused for 15 min (by using a double-blind procedure). Recordings were taken during a postinfusion baseline and in response to an orthostatic stressor (standing versus sitting postures). At the end of the metoprolol session, atropine sulfate was infused and responses were monitored during the postinfusion (i.e., double blockade) baseline and during orthostatic stressor. Analyses of the blockade data revealed that the preejection period (PEP) reflected sympathetic but not vagal influences on the heart, and high frequency (HF, 0.12-0.40 Hz) heart rate variability (respiratory sinus arrhythmia) reflected vagal but not sympathetic influences on the heart. No other measure provided a specific index of the tonic sympathetic or vagal activation of the heart. Postinfusion PEP under saline predicted individual differences in postinfusion cardiac sympathetic activation, whereas postinfusion heart period (but not HF variability) under saline predicted individual differences in postinfusion cardiac vagal activation.

Adult↗

PubMed1994

Autonomic cardiac control. III. Psychological stress and cardiac response in autonomic space as revealed by pharmacological blockades.

Behavioral contexts can evoke a variety of autonomic modes of response, characterized by reciprocal, coactive, or independent changes in the autonomic divisions. In the present study, we investigated the reactive autonomic control of the heart in response to psychological stressors, using quantitative methods for analyzing single and double autonomic blockades, and through the use of noninvasive indices based on heart period variability and systolic time intervals. Analysis of the effects of pharmacological blockades revealed an overall pattern of increased sympathetic and decreased parasympathetic control of the heart during speech stress, mental arithmetic, and a reaction-time task. Unlike the classical reciprocal sympathetic-parasympathetic response to orthostatic challenge, however, the responses of the autonomic branches to stress were uncorrelated. This reflected notable individual differences in the mode of autonomic response to stress, which had considerable stability across stress tasks. The putative noninvasive indices of sympathetic (preejection period) and parasympathetic (respiratory sinus arrhythmia) control changed in accord with the results of pharmacological blockades. Together, these results emphasize the substantial individual differences in the mode of autonomic response to stress, the advantages of a quantitative approach to analyzing blockade data, and the importance of validity estimates of blockade data.

Adult↗

PubMed1994

Individual differences in the autonomic origins of heart rate reactivity: the psychometrics of respiratory sinus arrhythmia and preejection period.

Heart rate reactivity has been conceptualized, at least implicitly, as a unidimensional construct ranging from low to high, reflecting individual differences in adrenergic reactivity to daily stressors. However, an individual's classification as high in heart rate reactivity ignores possible individual differences in the autonomic origins of this reactivity. Sixty-eight women were exposed to orthostatic and speech stressors to determine the psychometric properties (postural stability, convergent and discriminant validity) of heart rate, preejection period, and respiratory sinus arrhythmia. Results revealed that (a) basal, stress, simple reactivity (stress - baseline), and residualized change indices of heart rate, preejection period, and respiratory sinus arrhythmia were stable across postures and (b) heart rate reactivity was significantly related to preejection period and respiratory sinus arrhythmia reactivity, whereas the latter two measures were unrelated. Reactivity classifications may therefore be significantly improved by attention to concurrent estimates of the activity of both autonomic branches.

Adolescent↗

PubMed1993

Neurobehavioral organization and the cardinal principle of evaluative bivalence.

The principle of evaluative bivalence asserts that behavioral processes often organize along the evaluative dimension, due to a fundamental pattern of bivalent neurobehavioral organization extending throughout the neuraxis. This principle offers a powerful approach to the explication of complex behavioral relationships and the integration of diverse literatures. It also offers a guiding conceptual framework for the study of neurobehavioral relationships which holds the promise of integrating rather than diversifying the study of neural mechanisms for disparate behavioral phenomena.

Animals↗

PubMed1993

Rudimentary determinants of attitudes. II: Arm flexion and extension have differential effects on attitudes.

In the pain-flexor reflex, arm extension is temporally coupled with the onset of the unconditioned aversive stimulus, whereas flexion is associated with its offset; when retrieving desirable stimuli, arm flexion is more closely coupled temporally to the acquisition or consumption of the desired stimuli than arm extension. It was posited that these contingencies foster an association between arm flexion, in contrast to extension, and approach motivational orientations. Six experiments were conducted to examine this hypothesis. Ideographs presented during arm flexion were subsequently ranked more positively than ideographs presented during arm extension, but only when the Ss' task was to evaluate the ideographs when they were presented initially. Arm flexion and extension were also each found to have discernible attitudinal effects. These results suggest a possible role for nondeclarative memory in attitude formation.

Adult↗

PubMed1993

What underlies medical donor attitudes and behavior?

Donor attitudes, intentions, and behaviors have typically been conceptualized as organized along a bipolar continuum. This conceptualization is evident in I. G. Sarason et al.'s study of increasing participation in a bone-marrow registry in this issue. When the cumulative research on blood, bone-marrow, and organ donor behavior is considered, however, evidence suggests that a single, bipolar continuum may be insufficient and that a 2-dimensional (Positivity x Negativity) evaluative space may be minimally required to effectively represent and target the underlying substrates of donor behaviors. Negative beliefs and fears may constitute a particularly difficult obstacle to inducing donor behaviors and, thus, to promoting self-perceptions by people as donors. Understanding and changing these negative substrates, therefore, may be important if public health campaigns to increase donor behavior are to be cost-effective.

Attitude to Health↗

PubMed1993

Cardiac psychophysiology and autonomic space in humans: empirical perspectives and conceptual implications.

Contemporary findings reveal that autonomic control of dually innervated visceral organs does not lie along a single continuum extending from parasympathetic to sympathetic dominance. Rather, a bivariate autonomic space bounded by sympathetic and parasympathetic axes is the minimal representation necessary to capture the modes of autonomic control. We here empirically instantiate a quantitative bivariate model for the chronotropic control of the heart in humans. This model provides a more comprehensive characterization of psychophysiological response than simple measures of end-organ state and permits a differentiation of behavioral states and processes that would otherwise remain obscure. The model also illuminates and subsumes general principles such as the law of initial values and reveals a fundamental physiological rationale for the selection of heart period over heart rate as a metric for cardiac chronotropy. The present article also considers strategies for psychophysiological investigations within the autonomic space model, the limitations of these methods, and analytical tools for assessing their validity.

Adult↗

PubMed1993

Respiratory sinus arrhythmia: autonomic origins, physiological mechanisms, and psychophysiological implications.

Respiratory sinus arrhythmia (RSA) is being used increasingly in psychophysiological studies as an index of vagal control of the heart and may be among the most selective noninvasive indices of parasympathetic control of cardiac functions. A comprehensive understanding of RSA, however, requires an appreciation of its multiple autonomic and physiological origins. We review the physiological bases of RSA and show that RSA arises from multiple tonic and phasic processes of both central and peripheral origin. These underlying mechanisms are at least partially differentiated, have distinct dynamics and consequences, and may be differentially sensitive to behavioral and cognitive events. These multiple mechanisms are relevant for psychophysiological studies of RSA, and a thorough understanding of RSA can only be achieved through an appreciation of the dynamics of its underlying origins. There is a distinction between the psychophysiological and neurophysiological domains, and conceptual and empirical bridges between these domains are needed.

Arousal↗

PubMed1992

Vagal stimulation and cardiac chronotropy in rats.

Increasing frequencies of electrical stimulation of the right vagus nerve in the rat yielded a progressive lengthening of heart periods. Stimulation was capable of driving vagal control of cardiac chronotropy over its full physiological dynamic range, to the point of sinus block. The steady-state transfer function between vagal stimulation frequency and cardiac chronotropy was approximately linear, with a slope of 7.4 ms/Hz. The linearity of the stimulation-heart period function is consistent with previous reports in dogs, rabbits and humans, although the slope of the function was considerably lower in the rat.

Animals↗

PubMed1992

Social psychological contributions to the decade of the brain. Doctrine of multilevel analysis.

The 1990s were declared by Congress to be the "decade of the brain." This declaration is important to all psychologists, not only neuroscientists, because with this declaration come expectations of the cognitive and behavioral sciences generally and because the brain does not exist in isolation but rather is a fundamental component of developing and aging individuals who themselves are mere actors in the larger theater of life. This article examines the importance of a multilevel, integrative approach to the study of mental and behavioral phenomena in the decade of the brain, reviews how this approach highlights the synergistic relationship between theoretical and clinically relevant research, and illustrates how this approach can foster the transition from microtheories to general psychological theories.

Behavior↗

PubMed1992

Relationship between facial expressiveness and sympathetic activation in emotion: a critical review, with emphasis on modeling underlying mechanisms and individual differences.

Two important questions bearing on personality processes and individual differences are how do facial expressiveness and sympathetic activation vary as a function of the intensity of an emotional stimulus, and what is the functional mechanism underlying facial expressiveness and sympathetic activation in emotion? A formulation is proposed that is based on 2 propositions: (a) All strong emotions result in some degree of activation of the organism (i.e., principle of stimulus dynamism) and (b) there are individual differences in the gain (amplification) operating on the facial expressive and sympathetic response channels (i.e., principle of individual response uniqueness). This formulation organizes much of the existing data on internalizers and externalizers and yields novel predictions regarding the subpopulation labeled as generalizers.

Arousal↗

PubMed1992

Age-related changes in cardiovascular response as a function of a chronic stressor and social support.

The effects of aging, chronic stress, and social support on cardiovascular functioning were examined using a cross-sectional design. Thirty-six family caregivers of Alzheimer's disease victims and 34 control Ss performed 2 active coping tasks while continuous noninvasive measures of cardiovascular activity were monitored. Results revealed that caregivers high in social support displayed typical age-related decreases in heart-rate reactivity, whereas caregivers low in social support displayed age-related increases in heart-rate reactivity. Analyses further indicated that only Ss with low social support were characterized by age-related increases in systolic blood pressure. These results suggest that social support can moderate age-related changes in cardiovascular functioning, particularly in Ss exposed to a chronic stressor.

Adult↗

PubMed1991

Autonomic determinism: the modes of autonomic control, the doctrine of autonomic space, and the laws of autonomic constraint.

Contemporary findings reveal that the multiple modes of autonomic control do not lie along a single continuum extending from parasympathetic to sympathetic dominance but rather distribute within a 2-dimensional space. The physiological origins and empirical documentation for the multiple modes of autonomic control are considered. Then a formal 2-dimensional conception of autonomic space is proposed, and a quantitative model for its translation into a functional output surface is derived. It is shown that this model (a) accounts for much of the error variance that has traditionally plagued psychophysiological studies, (b) subsumes psychophysiological principles such as the law of initial values, (c) gives rise to formal laws of autonomic constraint, and (d) has fundamental implications for the direction and interpretation of a wide array of psychophysiological studies.

Animals↗

PubMed1990

Inferring psychological significance from physiological signals.

A century has passed since the publication of William James's Principles of Psychology, yet most of the questions James raised about the relation between physiological events and molar psychological or behavioral processes, such as emotion, remain unanswered. The sluggish progress in capitalizing on physiological signals to address general psychological questions is due in part to shortcomings in the quantification of physiological signals in humans and, perhaps more important, to the way in which investigators have been thinking about the relation between physiological signals and psychological operations. In this article, we illustrate these points, and we provide a conceptual framework to foster research and analysis of psychological phenomena based on physiological signals. Psychological operations and physiological responses are defined in terms of configural and temporal properties, and psychophysiological relations are conceptualized in terms of their specificity (e.g., one-to-one versus many-to-one) and their generality (e.g., situation or person specific versus cross-situational and pancultural). This model yields four classes of psychophysiological relations: (a) outcomes, (b) concomitants, (c) markers, and (d) invariants. Finally, the model specifies how to determine whether a psychophysiological relation is an outcome, concomitant, marker, or invariant, and it describes important limitations in inferences of psychological significance based on physiological signals when dealing with each.

Behavior↗