Respiratory Sinus Arrhythmia Predicts Heart Rate and Visual Responses during Visual Attention in 14 and 20 Week Old Infants

The prediction of cardiac attentional responses by respiratory sinus arrhythmia was tested in infants at 14 and at 20 weeks of age. Heart rate, heart rate variability, and respiratory sinus arrhythmia were measured in a 5-min baseline period. Respiration and heart rate responses were recorded during the habituation of infant visual attention. The level of respiratory sinus arrhythmia in the baseline was significantly correlated with the cardiac deceleration, especially in the 20-week-old infants. The relationship between cardiac and respiratory responses during attention was stronger in the 20-week-olds, paralleling the increase in respiratory sinus arrhythmia at this age. Visual fixation durations were also significantly correlated with measures of heart rate variability from the baseline. These results imply that cardiac variability not only predicts the level of cardiac attentional responsivity, but may be useful in the indexing of individual differences in the responsivity of more general attentional systems.     

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.     

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.     

Development and Stability in Visual Sustained Attention in 14, 20, and 26 Week Old Infants

Infants were studied at 14, 20, and 26 weeks of age in a longitudinal design. They were presented with varying and complex patterns on a TV screen. Two-thirds of the presentations were accompanied by a stimulus in the periphery delayed in time from the onset of fixation on the central stimulus. As in previous research, the infants were not as easily distracted by the interrupting stimulus when the presentation occurred at the point of maximal heart rate deceleration as when the presentation occurred at the end of the heart rate response. Infants with large amounts of respiratory sinus arrhythmia (i.e., heart rate variability) in a baseline recording were less distractible during the deceleration-defined trials than were infants with low amounts of respiratory sinus arrhythmia. Intra-individual patterns of development in respiratory sinus arrhythmia over the testing ages were closely paralleled by patterns of heart rate responding during sustained attention. Individual differences in baseline levels of heart rate and respiratory sinus arrhythmia were more stable than individual differences in sustained attention. The stability of attention responses over age may be mediated by the stability of the physiological system (e.g., heart rate, respiratory sinus arrhythmia, etc.), and by the within-age relation of attention to heart rate variability.     

Assessment of autonomic function by the spectral analysis of heart rate variability: an examination in a mirror drawing task]

The effect of an experimental task on autonomic function was investigated by spectral analysis of heart rate variability in 13 male college students. Power spectral density of heart rate variability has been said to contain two significant components: respiratory sinus arrhythmia (RSA) as an index of cardiac vagal activity, and Mayer wave related sinus arrhythmia (MWSA) as an index of sympathetic activity with vagal modulation. Those two components were examined during a task of mirror drawing on the CRT. In order to eliminate the effect of respiratory rate on RSA, the respiratory rate was controlled at 15 breaths/min. Furthermore, the coefficient of variance of R-R interval (CV-RR) and the fluctuation of plethysmograph (PTG) were calculated simultaneously. Results indicated that, while RSA decreased significantly, MWSA did not change during the task. On the other hand, neither CV-RR nor PTG showed any significant differences during the task. These findings indicated that cardiac parasympathetic activity was diminished in the mirror drawing task. The significance of spectral analysis of heart rate variability were discussed.     

Cardiac deceleration and E-wave brain potential components in young, middle-aged and elderly adults

Event-related potentials (ERPs), heart rate, and behavioral data were recorded from young, middle-aged, and elderly adults during an S1-S2 recognition memory paradigm. Anticipatory and evoked cardiac decelerations decreased significantly with age, as did the accuracy of recognition memory. The E-wave prior to S2 did not differ with age, however, and was not correlated with heart rate deceleration in any age group. Correlations between physiological measures and performance were weak in all groups. Taken together, the data provide little support for the hypothesis that the poorer recognition memory of older adults is related to an increasing uncoupling of E-wave and anticipatory heart rate with age.     

Event-related brain potential and heart rate manifestations of visual selective attention

Twenty-eight volunteers were instructed to attend stimuli presented at one side of the computer screen and to ignore stimuli presented at the other side. Both attended and unattended stimulus series consisted of targets (25%) and nontargets (75%) defined on the basis of stimulus shape. Attended targets required a binary choice based on stimulus color. Selective attention led to the expected increase in both midlatency (N2b) and late (P3) brain potential components. Furthermore, selective attention led to increased anticipatory cardiac slowing preceding the target stimulus and to increased primary bradycardia. Correlational analyses revealed a positive relation between the effects of selective attention on N2b amplitude and primary bradycardia suggestive of cortical involvement in the chronotropic control of heart rate.     

Individual differences in resting heart rate and spontaneous electrodermal activity as predictors of attentional processes: effects on anticipatory heart rate deceleration and task performance

The present study was concerned with the question of whether tonic resting heart rate (HR) and resting spontaneous electrodermal activity account for the association between anticipatory HR deceleration and task performance in a choice reaction time (RT) task with a fixed foreperiod. The task employed (a varied mapping paradigm) differed from simple RT tasks especially with regard to processing and attention demands. Subjects were required to determine as quickly and accurately as possible whether a 'complex' probe, presented for 80 ms, was identical or not to one of two distinct memory items, presented at the onset of each trial. Reaction times as well as accuracy of responses were determined. Additionally, reaction time and error data were synthesized to obtain a joint measure of response behaviour. The results of the present study were indicative of a reliable anticipatory HR deceleration extended over the last seconds preceding the probe stimulus. In agreement with previous findings, the HR deceleration grew stronger over blocks of trials and was sensitive to detection requirements, i.e. probe complexity. Furthermore, HR deceleration was related to task performance. Subjects with stronger decelerations (below the median on mean deceleration) exhibited a more impulsive (fast-inaccurate) and subjects above the median a more reflective (slow-accurate) response style. The effect was mainly due to a significant difference in RT. Further results indicated that the relationship between anticipatory deceleration and RT performance was especially due to the response behaviour of one group of subjects. Subjects above the median of resting HR and resting spontaneous electrodermal activity behaved in a prominent reflective manner and also displayed the lowest foreperiod deceleration. Results were discussed in terms of differences in the regulation or control of attentional processes.     

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.     

HEART RATE AND SOMATIC CHANGES DURING AVERSIVE CONDITIONING AND A SIMPLE REACTION TIME TASK

Four experiments are reported, all of which are concerned with evaluating in human Ss the relationship between the deceleration of heart rate, observed to anticipate both aversive and non-aversive stimuli, and several aspects of somatic-motor activity. In a simple reaction time task, a decrease in spontaneous bursts of EMG activity and both respiration amplitude and frequency were found to be concomitant with the deceleration of heart rate during the foreperiod and to be directly correlated with reaction time. The decrease in anticipatory somatic activity to an aversive stimulus was found in a second experiment to extend to spontaneous eye movements and blinks, which also had a marked concomitance with the anticipatory deceleration of heart rate. However, experimentally imposed somatic activity, i.e. continuous finger tapping, increased in intensity around the time the UCS was expected. A third experiment provided additional evidence that the anticipatory cardiac deceleration to aversive stimuli was not mediated significantly by respiratory maneuvers. Finally, evidence was provided that the basis for the spontaneous EMG bursts may be related to somatic responses elsewhere in the body, such as postural adjustments.     

The cardiac cycle time effect revisited: temporal dynamics of the central-vagal modulation of heart rate in human reaction time tasks

Lacey and Lacey (1974) suggested that during reaction time tasks higher brain centers dynamically adjust efferent vagal nerve pulses to the sino-atrial node of the heart, inducing phase-dependent heart rate changes. Since then, animal and human neuro-physiological results have provided evidence for this hypothesis. Higher subcortical and cortical brain centers may have reciprocal interactive pathways relating to autonomic control comparable to those at the level of peripheral autonomic changes and brain stem reflexes. In humans such central effects may be observed in the short latency vagal control of heart rate that has been studied mostly in reaction time (RT) tasks. RT task parameters modulate vagal pulses to the cardiac sino-atrial node (SAN), which in turn exerts a phase-dependent change in the ongoing cardiac interbeat interval. Simulations of human RT task effects in an animal model of heart rate change support this hypothesis. The current study examined evidence for vagal control of three human phasic heart rate responses in RT tasks. The evidence indicates that the initiation of an RT response triggers a reflexive shift from vagal activation to vagal inhibition. This shift is cardiac cycle phase dependent. Graded anticipatory cardiac deceleration during the warning interval of an RT task varies with task relevance and time uncertainty. This response may be part of a control process engaged in time keeping. Hence, temporal variables mediate the central-autonomic-vagal modulation of heart rate.     

Developmental differences in the preparatory heart rate response: childhood through adulthood

The present article examines developmental differences across childhood, adolescence, and adulthood in the triphasic anticipatory heart rate response and the impact of age on the relationship between anticipatory deceleration (D2) and reaction time (RT). Heart rate and RT were recorded from participants ages 5-25 during a fixed, 6 s anticipatory paradigm. The triphasic anticipatory heart rate response was larger in children, with the children displaying a delayed acceleratory component. Across this wide age range sample, D2 significantly predicted RT, but a model that included Age and D2 predicted significantly more of the RT variance. When comparing across ages on the triphasic response components or the relationship between D2 and RT, researchers should account for developmental effects.     

Developmental change in intentional action and inhibition: A heart rate analysis

The ability to inhibit is a major developmental dimension. Previous studies examined developmental change in instructed inhibition. The current study, however, focused on intentional inhibition. We examined heart rate responses to intentional action and inhibition, with a focus on developmental differences. Three age groups (8–10, 11–12, and 18–26 years) performed a child‐friendly marble paradigm in which they had to choose between intentionally acting on, or inhibiting, a prepotent response. As instructed, all age groups chose to intentionally inhibit on approximately 50 percent of the intentional trials. A pronounced heart rate deceleration was observed during both intentional action and intentional inhibition, but this deceleration was most pronounced for intentional inhibition. Heart rate responses did not differentiate between age groups, suggesting that intentional action and inhibition reach mature levels early in childhood.     

Anticipatory HR deceleration as a function of perceived control and probability of aversive loud noise: A deployment of attention account

Five groups of 10 undergraduate subjects each participated in an experiment to examine the effects of perceived control over, and the probability of occurrence of, noxious (white-noise) stimulation on anticipatory heart rate (HR) deceleration. All groups performed an arithmetic task, the numbers for which were changed on each of the 20 trials, but three groups were defined as active groups since they were instructed that the occurrence of noxious stimulation was contingent upon their performance on the task. The actual probability of occurrence of noxious stimulation (i.e., either 0.9, 0.5 or 0.1) was manipulated between these three groups. A fourth (passive) group (0.5 probability of occurrence) was instructed as to the non-contingent relationship between performance and the aversive white noise. The last group was a control group which only performed the task, and thus both provided an estimate of the rate of return to baseline following the expected HR acceleration to the task and eliminated the need for a within-subject control period to assess HR deceleration. The results indicated that all active and passive groups produced significant HR decelerations, relative to the control group, prior to the noxious stimulus. However, all active groups (regardless of probability levels) displayed significantly greater, and required more trials to maximally develop, anticipatory deceleration than the passive group. In addition, the results for the active groups revealed a direct relationship between the probability of occurrence of noxious stimulation and the magnitude of anticipatory deceleration. It is argued that the results cannot be adequately accommodated by the preparatory-adaptive-response theory. A deployment-of-attention account is suggested since it appears both to account for the obtained pattern of results completely and to generate additional testable predictions for the future.     

Cardiac responses associated with affective processing of unpleasant film stimuli.

The autonomic basis of cardiac reactions to unpleasant film stimuli was investigated. Film clips depicting major surgery, threats of violence, and neutral material were presented to 46 subjects. Self-report measures of emotion were obtained, as well as heart rate, respiration rate, respiratory sinus arrhythmia, T-wave amplitude and skin conductance level. Resting vagal tone was estimated in a paced breathing task prior to film viewing. Spontaneous blink rate was also taken as a measure of visual engagement during film viewing. Coherent increases in sympathetic activation accompanied the film containing violent threats, whereas the surgery film yielded greater electrodermal activation, as well as heart rate deceleration and T-wave increase. These data support the hypothesis of differential autonomic response patterns to specifically unpleasant material. As compared with threat and neutral films, greater blink rate inhibition was observed during the surgery film. Individual differences in parasympathetic cardiac control measured at rest were able to discriminate cardiac response patterns during film viewing.     

Baseline respiratory sinus arrhythmia and heart rate responses during sustained visual attention in preterm infants from 3 to 6 months of age

Three groups of preterm infants were studied longitudinally at 14, 20, and 26 weeks of age (corrected for gestational age). The groups included infants with no perinatal medical complications, those with mild respiratory problems requiring ventilatory assistance, and those with respiratory distress syndrome. Baseline heart rate and respiratory sinus arrhythmia (RSA) were recorded for 5 min, and heart rate was also recorded while the infants engaged in sustained visual attention to stimuli presented on video monitors. The heart rate response during stimulus orienting and sustained attention was smaller in those infants with respiratory distress syndrome than in the other preterm infants and in comparison with the response seen in full-term infants in previous research. Magnitude of RSA was positively correlated with the attention responses irrespective of the preterm group assignment. There was greater stability in baseline heart rate and RSA for the preterm infants than has been found with full-term infants. These data suggest that the cardiorespiratory functioning of the preterm infant indexes a stable individual difference characteristic that is correlated with heart responses during sustained attention, and heart rate attention systems may be damaged in the high-risk preterm infant.     

Age effects on heart rate,sustained potential,and P3 responses during reaction-time tasks

—Relationships between physiological responses and slowed reaction time (RT) among elderly subjects were tested in 48 healthy young, middle-aged, and elderly men (mean ages 24, 45, and 71 years) using signaled simple and choice RT tasks. There were age reductions in P3 amplitude and heart rate (HR) deceleration, but no effects of age on P3 latency. Sustained potential (SP or CNV) amplitude paradoxically increased with age, possibly indicating weaker inhibitory function. P3 amplitude, SP amplitude, and HR deceleration were most strongly correlated with RT among younger subjects, but SP amplitude was correlated with RT in the elderly group during the choice task. HR deceleration shared a small amount of variance with SP amplitude and RT in the young group. There was no HR-SP-RT relationship in the older groups. Choice-simple task differences in P3 amplitude and RT were correlated in the young and elderly groups. The results suggest that HR, SP, and P3 responses may reflect physiological processes related to the slower RTs of healthy elderly subjects.     

Pericranial muscular,respiratory, and heart rate components of the orienting response

We have earlier found that voluntary attention to weak auditory stimuli induces inhibition of respiration, heart rate, and electromyographic (EMG) activity of masticatory and lower facial muscles and that these responses lower the auditory threshold for low-frequency sounds. In the current study, we examined whether this inhibitory response pattern also occurs during involuntary orienting to novel, nonsignal sounds. Environmental sounds of low intensity were presented unexpectedly during the performance of a reading task. Orienting responses (ORs) were elicited as indicated by heart rate deceleration and skin conductance responses. Inhibitory respiratory and pericranial EMG responses appeared to be intrinsic components of the OR. Together with the autonomic responses, they habituated when a nonsignal auditory stimulus was repeatedly presented. Our results also suggest that eye and pinna movements occurred toward the sound source. The results of the current study are consistent with the hypothesis of Sokolov (1963) that the primary function of the OR is enhancement of sensory sensitivity.     

Respiration Sinus Arrhythmia in Psychotic Children

Ten psychotic and 10 normal children, paired for age and sex, were compared for respiratory sinus arrhythmia differences under conditions of spontaneous and 5, 10, and 15 sec interval breathing. Cardiac rate and respiratory changes were simultaneously recorded. Parameters of degree of change and timing for each respiratory-cardiac cycle and its associated changes in heart rate were measured and compared statistically. Results show significant differences between psychotics and normal controls as follows:

• 1 The psychotics did not sustain the acceleratory phase of the cardiac cycle as did the controls.
• 2 The lag intervals (interval between onset of inspiration and onset of cardiac acceleration, interval between onset of expiration and onset of cardiac deceleration) were more consistent for the normal controls than for the psychotics.
• 3 At maximum respiratory depths the psychotics no longer demonstrated a direct relationship between depth of respiration and degree of cardiac rate change as did the controls.

We conclude that there is a different or less well-coordinated combination of operative forces in the sinus arrhythmia mechanism of the psychotics as compared to the controls.     

A comparison of cardiovascular and autonomic adjustments to three types of cold stimulation tasks.

Two types of 'cold pressor' tasks are used frequently in research settings: immersing the hand or foot in ice water, and applying an icebag to the forehead. Both tasks have commonly been selected as 'alpha-adrenergic' tasks due to expected increases in blood pressure and peripheral resistance. However, the forehead cooling task has been used by others to produce increased vagal tone due to the elicitation of the 'diving reflex' and subsequent bradycardia. This differs from the prototypical increase in heart rate during hand immersion. The present study directly compared the cardiovascular adjustments of hand immersion and forehead stimulation. As stimulation of the trigeminal nerve is thought to increase vagal activity during forehead cooling, a third condition in which most of the face was covered with an icebag was included to ostensibly stimulate more of the trigeminal. 18 males had counterbalanced exposures to hand immersion, forehead cooling, and facial cooling for 90 s each. Cardiovascular variables derived from impedance cardiography and the ECG were measured. Respiration was paced at 14 breaths/min to facilitate comparisons of respiratory sinus arrhythmia across conditions. No differences among baseline or tasks were found for respiratory rate or cardiac output. The pattern of results for hand immersion was that of increased heart rate with moderate blood pressure increases. In contrast, the forehead and facial cooling tasks elicited small heart rate decreases with little change in blood pressure. Facial cooling elicited significantly more vagal activation than hand cooling as indexed by respiratory sinus arrhythmia. The patterns of response for facial and forehead cooling were almost identical. Probable reasons for the lack of significant blood pressure responses during the facial and forehead cooling are discussed.