Phasic Heart Rate Changes Research Articles

Evoked K-complexes and altered interaction between the central and autonomic nervous systems during sleep in alcohol use disorder.

There is evidence for impairment in both central nervous system (CNS) and autonomic nervous system (ANS) function with prolonged alcohol use. While these impairments persist into abstinence, partial recovery of function has been demonstrated in both systems during sleep. To investigate potential ANS dysfunction associated with cortical CNS responses (impairment in CNS-ANS coupling), we assessed phasic heart rate (HR) fluctuation associated with tones that did and those that did not elicit a K-complex (KC) during stable N2 non-rapid eye movement (NREM) sleep in a group of 16 recently abstinent alcohol use disorder (AUD) patients (41.6±8.5 years) and a group of 13 sex- and age-matched control participants (46.6±9.3 years). Electroencephalogram (EEG) and electrocardiogram (ECG) data were recorded throughout the night. Alcohol consumption questionnaires were also administered to the AUD patients. AUD patients had elevated HR compared to controls at baseline prior to tone presentation. The HR fluctuation associated with KCs elicited by tone presentation was significantly smaller in amplitude, and tended to be delayed in time, in the AUD group compared with the control group, and the subsequent deceleration was also smaller in AUD patients. In both groups, the increase in HR was larger and occurred earlier when KCs were produced than when they were not, and there was no difference in the magnitude of the KC effect between groups. Phasic HR changes associated with KCs elicited by tones are impaired in AUD participants, reflecting ANS dysfunction possibly caused by an alteration of cardiac vagal trafficking. However, only the timing of the HR response was found to relate to estimated lifetime alcohol consumption in AUD. The clinical meaning and implications of these novel findings need to be determined.

Differential heart rate responses to social and monetary reinforcement in women with obesity.

Obesity is often accompanied by weight stigmatization; subsequently, individuals with obesity frequently face social rejection. It has been shown that recurrent negative social experiences can alter the perception of social cues. However, the way individuals with obesity process social stimuli is not well understood. This study aims to investigate obesity-related alterations in social compared to nonsocial information processing. Women with obesity (n = 14) and without obesity (n = 14) participated in a social and a monetary incentive delay task in which they anticipated and received positive, negative, and neutral outcomes in the form of faces or money. During the experiment, phasic heart rate changes and reaction times were measured. Women with obesity, compared to lean women, exhibited a stronger differentiation during the anticipation of monetary and social reinforcement, showing slower reaction times to social cues compared to monetary cues. During the outcome processing phase, women with obesity relative to controls demonstrated diminished heart rate responses particularly to negative social outcomes. Interestingly, differences in cardiac responses in participants with obesity were moderated by weight-related teasing experiences. In women with obesity, a higher BMI was associated with blunted cardiac responses to social cues relative to monetary cues only if they reported more emotional pain after weight-related teasing. Our results contribute to a better understanding of social information processing in obesity and give first evidence for the role of negative social experiences in reinforcement processing.

Executive functioning in attention-deficit/hyperactivity disorder: questioning the notion of planning deficits with heart rate reactivity

This study employed a paired stimulus paradigm to compare phasic changes in heart rate among children (age categories 6-8, 9-10, and 11-12) and adults (age categories 18-19 and 20-22) with attention-deficit/hyperactivity disorder (ADHD) and age-matched controls. A sample of 95 participants (19 ADHD-diagnosed children, 34 controls, 20 ADHD-diagnosed adults, and 22 controls) solved a planning task, the Tower of London, through 4 levels of difficulty. It was hypothesized that groups with ADHD would show greater heart rate acceleration and less final deceleration than would controls, and that these heart rate responses would change with age and difficulty level as well. Though heart rate differences were found among age categories and difficulty levels, none were found between participants with ADHD and controls. The lack of ADHD differences are not consistent with the behavioral evidence that planning by itself is one of the marked executive function deficits in ADHD. Because ADHD differences were not evident, the effects either were not present or were smaller than that of difficulty level and age. Possible explanations for this lack of difference and future directions are discussed.

Framing the Ultimatum Game: Gender differences and autonomic responses

The present study aimed at investigating whether the way offers are framed in the Ultimatum Game (UG) affects behavioral and autonomic responses in men and women. The "I give you" and "I take" expressions were used as gain and loss frames, respectively. Skin conductance and heart rate were recorded as indices of autonomic activation in response to unfair, mid-value, and fair offers. Acceptance rates were higher in men than in women under the gain frame. Moreover, men showed higher acceptance rates under the gain than under the loss frame with mid-value offers, whereas women's choices were not affected by frame. On the physiological level, men produced differential autonomic response patterns during decision-making when offers were presented under gain and loss framing. The "I take" frame, by acting as a loss frame, elicited in men the characteristic defensive response pattern that is evoked by aversive stimulation, in which increases in skin conductance are coupled with increases in heart rate. On the other hand, the "I give you" frame, by acting as a gain frame, elicited in men increases in skin conductance associated with prevailing heart rate deceleratory responses, reflecting a state of enhanced attention and orienting. In contrast, women's autonomic reactivity was not affected by frame, consistent with behavioral results. Phasic changes in heart rate were crucial in revealing differential functional significance of skin conductance responses under different frames in men, thus questioning the assumption that this autonomic measure can be used as an index of negative emotional arousal in the UG.

Phasic heart rate changes during word translation of different difficulties

The heart rate (HR) can be modulated by diverse mental activities ranging from stimulus anticipation to higher order cognitive information processing. In the present study we report on HR changes during word translation and examine how the HR is influenced by the difficulty of the translation task. Twelve students of translation and interpreting were presented English high- and low-frequency words as well as familiar and unfamiliar technical terms that had to be translated into German. Analyses revealed that words of higher translation difficulty were accompanied by a more pronounced HR deceleration than words that were easier to translate. We additionally show that anticipatory HR deceleration and HR changes induced by motor preparation and activity due to typing the translation do not depend on task difficulty. These results provide first evidence of a link between task difficulty in language translation and event-related HR changes.

Attentive Perception Can Diminish Vagal Inhibition

A systematic decrease in heart rate when anticipating an important stimulus or when preparing to react is called anticipatory bradycardia. Numerous studies have shown that the initiation of motor activity prompts the termination of anticipatory bradycardia in reaction time tasks. However, in experiments with procedures based on more complex reactions, the termination of anticipatory bradycardia is delayed until later cardiac cycles. This unexpected effect may be attributed to perceptual processes that are engaged in the feedback mechanism essential for effectiveness in prolonged and complex motor reactions. The experiment presented in this article was carried out to verify the hypothesis that the initiation of a motor reaction, when processed simultaneously with sustained attentive perception, does not evoke acceleration of heart rate. The experimental task was a simulated shooting at a moving target. The procedure in the experimental group induced participants to attentively observe events before and after the required reaction, whereas in the control group, attentive perception of task events after the reaction was not possible. The expected pattern of heart-rate changes appeared in the experimental group. During the initial block of trials, the initiation of the motor reaction did not evoke immediate termination of anticipatory bradycardia. During later trials in the experimental group and during all trials in the control group, heart-rate changes were completely typical - heart rate increased after the motor reaction began. The results show that attentive perception engaged immediately after the initiation of motor activity can affect the pattern of phasic heart-rate changes observed during typical reaction time tasks. Additionally, the difference between the patterns characteristic of the initial and later trials suggests possible competition between the neuronal influences that modulate heart rate.

An open-source LabVIEW application toolkit for phasic heart rate analysis in psychophysiological research

The cardiovascular system has been extensively measured in a variety of research and clinical domains. Despite technological and methodological advances in cardiovascular science, the analysis and evaluation of phasic changes in heart rate persists as a way to assess numerous psychological concomitants. Some researchers, however, have pointed to constraints on data analysis when evaluating cardiac activity indexed by heart rate or heart period. Thus, an off-line application toolkit for heart rate analysis is presented. The program, written with National Instruments' LabVIEW, incorporates a variety of tools for off-line extraction and analysis of heart rate data. Current methods and issues concerning heart rate analysis are highlighted, and how the toolkit provides a flexible environment to ameliorate common problems that typically lead to trial rejection is discussed. Source code for this program may be downloaded from the Psychonomic Society Web archive at www.psychonomic.org/archive/.

Developmental Change in Feedback Processing as Reflected by Phasic Heart Rate Changes.

Heart rate was recorded from 3 age groups (8-10, 12, and 20-26 years) while they performed a probabilistic learning task. Stimuli had to be sorted by pressing a left versus right key, followed by positive or negative feedback. Adult heart rate slowed following negative feedback when stimuli were consistently mapped onto the left or right key (response-dependent condition) but not when responses to stimuli were always followed by negative feedback (uninformative condition). Young children's heart rate showed slowing following both response-dependent and uninformative negative feedback. These findings suggest that the ability to assess the relevance of performance feedback improves with age, resulting in improved adjustment to dynamical changes in the task environment.

Developmental change in auditory selective attention as reflected by phasic heart rate changes

Heart rate was recorded from five different groups of children (ages 7, 10, 12, 14, and 20 years) while they were performing an auditory selective attention task. The participants were instructed to count rare tone pips embedded in a series of standard tone pips presented at one (attended) ear while ignoring rare and standard stimuli presented at the other (unattended) ear. A pattern of anticipatory heart rate deceleration followed by acceleration was associated with rare tone pips at the attended ear but not with rare tone pips that should be ignored. The absence of differential sensitivity of heart rate responses to rare tone pips presented at the unattended ear was observed for all age groups. These findings were interpreted to suggest that the ability to ignore irrelevant target stimuli has reached mature levels during middle childhood. The depth of anticipatory deceleration increased until age 14, suggesting that the ability to maintain attentional set continues to develop beyond childhood.

Evoked heart rate and blood pressure in an S1–S2 paradigm

Phasic changes in heart rate (HR) and blood pressure (BP) in an S1–S2 paradigm were studied in three experiments. In each experiment, a memory search task was performed at S1. The outcome of this task indicated whether a fast or a delayed response had to be given after S2. Besides this response instruction, there were two other task manipulations: in one experiment the memory load at S1 was varied, whereas in each experiment a different kind of performance feedback was given. Both HR and BP showed a triphasic pattern, consisting of an initial decrease, followed by an increase and another decrease. The BP patterns were quite consistent, and delayed a few seconds relative to the HR pattern. The memory load manipulation at S1 showed that the changes early in the S1–S2 interval (initial decrease and subsequent increase) reflect the processing of S1. The effects of response instruction showed that the second HR deceleration, and the subsequent BP decrease, reflect the preparation of the motor response. In Experiment 2 the level of the evoked HR and BP patterns was shifted as a function of the type of reward (a bonus or noise).

Development of fear-related heart rate responses in neonatal rabbits

Classical simple conditioning of heart rate (HR) was studied in rabbits between the 1st and 18th neonatal day. An auditory stimulus (1000 Hz, 5 s) served as the conditioned stimulus (CS), and a train of electric impulses (100 Hz, 500 ms, 1–1.5 mA) was used as the unconditioned stimulus (US). HR responses developed during orientation session (CS-alone) as well during acquisition (CS-US paired) were analyzed and compared to those developed by young adult rabbits (3-month-old). In all neonatal animals tested, baseline HR measured during an adaptation session preceding conditioning, was similar though significantly higher than that measured in adult rabbits (Newman-Keuls P < 0.05). Before the 10th neonatal day, the animals did not show either somatomotor or HR orienting responses to the CS-alone presentations. Consequently, since orienting reactions play a necessary role in the formation and manifestation of conditioned reflexes, 1 to 10-day-old infant rabbits were not submitted to the acquisition session. All the other neonatal groups, while showing orienting behaviours similar to those exhibited by adults (head and pinna movement), presented different patterns of HR orienting responses (no response, bradycardia, tachycardia, bradycardia/tachycardia etc.). As for the acquisition session, the first bradycardic response, similar to that developed by adult rabbits, was found in 18-day-old rabbits. However, also in this neonatal group the amplitude of the conditioned response was significantly smaller when compared to that exhibited by young adults (Newman-Keuls P < 0.01). In addition, in some of the 10-day-old neonates, HR appeared very unstable and dropped to very low values (as low as 146 beats/min) early during conditioning, apparently as a consequence of CS-US association. As for the unconditioned response, no differences were found between adult rabbits and the neonatal animals older than 12 days. In contrast, most of the 10-day-old rabbits showed either bradycardia or no response to the unconditioned stimulus. Considering the ability of mammalian infants to learn somatomotor conditioned responses at early stages of maturation, conditioning of HR responses occurs late during ontogeny. Since this incapacity to show HR conditioned responses before the 18th postnatal day cannot be ascribed to their inability to show phasic HR changes nor to a failure in detecting the auditory stimulus, these results suggest the possibility that HR conditioned responses may be mediated by neural structures developing later during maturation.

Autonomic mediation of unconditioned and conditioned heart rate responses in the 16-day-old rat

In three experiments, we examined the cardiac response of 16-day-old rats to a 10-sec olfactory stimulus before and after aversive Pavlovian conditioning. The unlearned (orienting) response to the novel stimulus was bradycardia, and the conditioned response was a brief period of bradycardia early in the conditioned stimulus, followed by pronounced tachycardia. After selective blockade of the parasympathetic and sympathetic systems with atropine or atenolol, the deceleratory orienting response was found to be the result of an increase in vagal discharge, accompanied by a co-occurring decrease in sympathetic stimulation of the heart. The initial deceleratory component of the conditioned response was produced by an increase in parasympathetic stimulation of the heart, and the acceleratory component was generated by an increase in sympathetic activity. These results are discussed in terms of their significance for the neural and autonomic origins of the phasic changes in heart rate that are elicited by the olfactory stimulus during different stages of conditioning.

Age differences in responses to temporally modulated patterns at 6 and 12 weeks

In this study of young infants' attentive responses to patterned visual stimuli, 6- and 12-week-old groups of infants responded differently, based on behavioral and cardiac indices of attention, to temporal modulation. Looking behavior and phasic heart-rate changes were measured while infants viewed checkerboard and bull's-eye patterns presented continuously, flashed at 1 Hz, or flashed at 5 Hz. For 12-week-oid subjects, visual fixation increased with increasing flashing rate, and cardiac responses were more decelerative to flashing than to continuous patterns. For 6-week-old subjects, total durations of visual fixation did not differ among conditions; however, durations of first fixation to each pattern were reduced in the flashing conditions. These infants showed slight decelerative cardiac responses to the continuous and 1-Hz patterns but markedly accelerative responses to the 5-Hz patterns. State changes and/or movement increases were coded from videotape and were rejected as major contributors to this accelerative response. The observed differences between 6- and 12-week-old infants add to a multitude of evidence suggestive of discontinuities around 2 months of age.

Effects of sympathetic tone on vagally induced phasic changes in heart rate and atrioventricular node conduction in the anesthetized dog.

We examined the effects of stellate ganglia stimulation on the phase-dependent chronotropic and dromotropic responses to brief vagal bursts in open-chest anesthetized dogs. Stellate stimulation affected the phasic vagal effects on heart rate by shortening the latent period, shifting the phase at which maximum decrease in heart rate occurred to earlier phases, and reducing the maximum decrease in heart rate. These effects were due primarily to an increase in the basic heart rate. No significant sympathetic-parasympathetic interaction occurred for heart rate, indicating that accentuated antagonism did not occur with brief vagal bursts. Stellate stimulation primarily decreased the amplitude of the phasic vagal effects on atrioventricular nodal conduction, regardless of the underlying heart rate, and a significant sympathetic-parasympathetic interaction was associated with this effect. The peak of the phase-dependent vagal effects on heart rate and atrioventricular nodal conduction were phase-shifted with one another. From these findings, we postulate the small changes in sympathetic tone might shift the predominant phase-dependent vagal effect from one on heart rate to one on atrioventricular nodal conduction. Furthermore, our results suggest that dynamic vagal control of heart rate and atrioventricular node conduction involves both phase-dependent and phase-independent factors. Sympathetic activity appears to affect only the phase-independent factor(s) in the control of heart rate, whereas it affects both phase-dependent and phase-independent factors in the control of atrioventricular node conduction.

Electrocardiographic T-wave changes are more pronounced in type A than in type B men during mental work.

Phasic changes in heart rate (HR) and electrocardiographic T-wave amplitude (TWA) were monitored in healthy Type A (coronary-prone) and Type B (non-coronary-prone) men during the performance of a difficult arithmetic task. Type As showed significantly greater reductions in TWA as compared to Type Bs, though no group differences were present in HR change. This pattern of results, wherein a significant Type A-B difference was observed in a phasic measure of ventricular performance (TWA), but not in one of supraventricular performance (HR), suggests that Type As experience excessive neurally mediated sympathetic stimulation of the myocardium during mental work.

Cardiac orienting and habituation to auditory and vibrotactile stimuli in the infant decerebrate rat.

Phasic changes in heart rate were used to evaluate sensory reactivity and habituation in 5- and 12-day-old normal and decerebrate rats. Twenty-four and forty-eight hours after thalamic transection, temporally paired auditory or vibrotactile stimuli were repeatedly presented in a sensory disparity paradigm. While tone stimuli failed to evoke consistent cardiac change, vibrotactile stimuli produced cardiac decelerations, characteristic of the orienting response, in all subject groups. The magnitude of this response was comparable in both normal and decerebrate subjects at 5 days of age, but demonstrated a more notable increase with age in the normal subjects. Habituation of the cardiac response was apparent in all groups, and was not significantly different in the normal and decerebrate subjects. No consistent responses were apparent in any group to the unexpected omission of the second stimulus of the pair. Results indicate that orienting and habituation processes can persist in the absence of the cerebral hemispheres and support the view that lower levels of the neuraxis are capable of mediating a range of adaptive functions.

Phasic changes in heart rate and respiration correlated with PGO-spike activity during REM sleep

The correlation between PGO-spike activity and phasic changes in heart rate and respiration during REM sleep has been studied in unrestrained cats.