bluuebunny/crossref_metadata_2025_split huggingface dataset:
Measuring Baseline‐Treatment Differences in Heart Rate Variability: Variance versus Successive Difference Mean Square and Beats per Minute versus Interbeat Intervals
Authors: Heslegrave Ronald J. , Ogilvie John C. , Furedy John J. 
Published: February 2007

ABSTRACTIt is argued that: if linear trends are present in heart rate (HR) data, due to sinus arrhythmic variation and the gradual nature of the HR response to an external treatment, the time‐series statistic successive difference mean square (SDMS) will be a logically more appropriate estimate of HR variability than is variance. A fifty‐subject study assessed both the empirical import of this argument as well as the question of the appropriate scale of measurement, i.e., either beats per minute (BPM) or interbeat intervals (IBI). Separate analyses to determine changes in HR variability from baseline to treatment conditions were carried out using each combination of statistic and scale to define HR variability. These analyses showed that HR variability either did not change or was significantly decreased by the treatment depending on the combination of statistic and scale used to define HR variability. This differential result, depending on the type of analysis, was due to the fact that nonrandom linear trends in the HR data spuriously inflated variance relative to SDMS and affected the BPM scale significantly more than the IBI scale. The major result from this study is that the combination of SDMS as the variability statistic, and IBI as the scale of measurement for HR, is both the best and most appropriate technique for assessing changes in HR variability. In addition, the IBI scale should be considered when analyzing mean HR scores if differential linear trends exist between conditions being compared, as in this case, since the IBI scale should increase statistical precision for detecting differences between mean HR scores during those conditions. Finally, when the more appropriate SDMS statistic and IBI scale define HR variability, this study supports the claims of previous investigators who have reported that increases in cognitive functioning led to decreases in HR variability.
Microneurography: A Technique Producing Information about Factors Affecting Cardiovascular Control
Authors: Wolf Steven L. 
Published: February 2007

ABSTRACTThis article discusses the technique of microneurography and its limitations. Stimuli capable of changing sympathetic neural discharge, recorded from peripheral nerves in conscious subjects, are noted. The notion that both internal and external stimuli can alter sympathetic activity should encourage psychophysiologists to examine these factors as possible elements used by subjects to process signals representing a component of autonomic behavior.
Vaginal and Pelvic Floor Responses to Sexual Stimulation
Authors: Gillan Patricia , Brindley G. S. 
Published: February 2007

ABSTRACTVaginal vascular responses to vibratory stimulation of the clitoris, recorded as changes in the amplitude of oscillations of light reflectance at the heart‐beat frequency, are: a) very repeatable, b) widespread throughout the vagina but of greater amplitude in its lower anterior wall than elsewhere, c) of very short latency (2–3 sec), but cumulative over 30 sec or more. Such responses are not imitated by raising the abdominal pressure, voluntarily contracting the pelvic floor or the flexors or adductors of the hips, or raising the blood pressure by exercise. They are absent in the foot, hand and rectum when present in the vagina. Sexual fantasy provokes vaginal responses very similar to those from vibratory stimulation of the clitoris, though somewhat less repeatable. Mean vaginal light reflectance, averaged over a cardiac cycle, responds to the same stimuli which affect the amplitude of pulsation. It is, however, much more subject to artifact. Changes in thermal conductivity closely parallel those in amplitude of oscillation of reflectance, with a time‐lag which is probably mainly instrumental. Vibratory stimulation of the clitoris causes sustained reflex contraction of the pelvic floor. This reflex (never, it seems, previously described) may be regarded as a tonic counterpart of the well‐known phasic bulbocavernosus reflex. The vascular events at and after orgasm and their relationship to features of the pelvic floor electromyogram are described and illustrated; the heart rate falls greatly during the 10 sec after orgasm, the amplitude of vaginal vascular pulsation remains above its prestimulation value for as long as 15 min, and pelvic floor electromyographic activity remains enhanced for at least 2 min.
Generalization of Conditioned Muscle Tension: A Closer Look
Authors: Glaus Kathleen D. , Kotses Harry 
Published: February 2007

ABSTRACTIn EMG biofeedback it has been suggested that covariation in tension levels between a trained and untrained muscle increases with continued training of the target muscle. Predictions of this sort are in contrast to the notion of response generalization which would predict decreased covariation between trained and untrained muscles with continued training. This study examined covariation between facial and forearm EMG levels during facial EMG biofeedback, and evaluated changes in such covariation which occurred with continued facial EMG training. Two groups of individuals were trained either to increase or to decrease facial muscle tension in 3 laboratory sessions during which simultaneous measures of facial and forearm EMG were obtained at 1‐min intervals. Comparison of facial EMG measures for these groups with those for a third, noncontingent control group revealed bidirectional conditioned effects for each training session. Some covariation between forearm and facial EMG was apparent for all groups. However, examination of change in covariation across sessions revealed that covariation decreased for groups receiving facial muscle training, whereas covariation levels exhibited by the noncontingent feedback group remained stable. This finding was consistent with the concept of response generalization but not with the notion of muscle tension generalization as employed in EMG biofeedback.
Pre‐ejection Period: Measuring Beta‐adrenergic Influences Upon the Heart
Authors: Newlin David B. , Levenson Robert W. 
Published: February 2007

ABSTRACTIncreasing interest among psychophysiologists in sympathetic (beta‐adrenergic) influences upon the heart has created the need for noninvasive techniques for assessing these influences. The validity of pre‐ejection period (PEP), a systolic time interval, as a measure of beta‐adrenergic influences upon myocardial contractility is evaluated. Details of a procedure for determining PEP using a polygraph and digital computer are presented. This methodology is then applied to an experiment in which the intracardiac (PEP) and arterial subintervals of pulse transmission time (PTT) are measured during biofeedback‐assisted control of PTT in order to evaluate the relative contribution of changes in PEP to PTT control.
Myocardial Dysfunction and Pathology Associated with Environmental Stress in Squirrel Monkey: Effect of Vagotomy and Propranolol
Authors: Corley K. C. , Mauck H. P. , Shiel F. O'M. , Barber J. H. , Clark L. S. , Blocher C. R. 
Published: February 2007

ABSTRACTThe influence of autonomic innervation on stress‐induced cardiomyopathy and heart rate changes was analyzed by selective removal of parasympathetic and sympathetic myocardial inputs. Squirrel monkeys with bilateral cervical vagotomy or β‐adrenergic receptors blocked by propranolol were studied in shock stress and restraint situations. Because propranolol reduced stress‐induced lesions and tachycardia, enhanced sympathetic β‐receptor activity was considered responsible for these effects in intact monkeys. No role for increased parasympathetic activity in myocardial pathology was indicated. Enhanced sympathetic activity was also implicated by lesions and tachycardia of vagotomy monkeys. However, vagotomy alone induced myocardial pathology and confounded the effects of shock stress. Stress‐induced cardiac arrest in both vagotomy and propranolol monkeys was observed. An imbalance of either autonomic input was suggested to be responsible for this dysfunction. Thus, autonomic innervation was involved in stress‐induced cardiomyopathy and heart rate changes.
Pulse Transit Time: Relationship to Blood Pressure and Myocardial Performance
Authors: Obrist Paul A. , Light Kathleen C. , McCubbin James A. , Hutcheson J. Stanford , Hoffer J. Lee 
Published: February 2007

ABSTRACTThe purpose of this research was to evaluate, in human subjects, the degree to which pulse transit time (PTT) covaries with systolic (SBP) and diastolic (DBP) blood pressure, and the degree to which PTT is sensitive to sympathetic influences on myocardial performance. Six studies were performed involving 118 young adult males. In all subjects, cardiovascular activity was assessed in both the resting state and during three stressors: the cold pressor, a pornographic movie and unsignaled shock avoidance reaction time task. The studies differed with respect to where on the arterial tree the pulse wave was transduced, whether blood pressure was measured invasively or noninvasively, and whether the myocardial sympathetic innervations were intact or not. It was observed that PTT covaried quite consistently with SBP but very inconsistently with DBP. The degree of covariation was influenced by the individual's reactivity and, with DBP, by the type of stress. PTT was appreciably influenced by myocardial sympathetic excitation and to a lesser degree by vascular processes. The use of PTT as an index of blood pressure and myocardial performance is discussed.
Effects of Electrodermal Lability and Introversion on Vigilance Decrement
Authors: Hastrup Janice L. 
Published: February 2007

ABSTRACTPrevious research has suggested that an autonomic nervous system measure, electrodermal lability, and a personality measure, introversion‐extraversion, both predict vigilance decrement; mixed results have been obtained in research seeking to correlate these two variables. Two vigilance tasks requiring an easy and a difficult sensory discrimination produced an overall decline in performance over time, but electrodermally labile subjects (those with high frequencies of spontaneous fluctuations of skin conductance and slow habituation to a series of tones) did not show a decline on the difficult task. Signal detection measures of sensitivity and response bias suggest that the Observed differences reflected changes in sensitivity over time and not just differences in criterion for responding. While not correlated with electrodermal lability, introversion was related to a higher initial level of performance on the difficult task. Vigilance tasks requiring rapid but cognitively sample discriminations appear to be more effective in eliciting overall declines in performance. The presence of such a decline may be necessary for observing differential declines in performance between electrodermal labiles and stabiles.
An Anal Probe for Monitoring Vascular and Muscular Events During Sexual Response
Authors: Bohlen Joseph G. , Held James P. 
Published: February 2007

ABSTRACTA method for quantifying physiological changes in the pelvis during sexual response is presented. The basis of the system is an anal probe which simultaneously measures changes in blood volume and muscle tension in men and women. An LED‐transistor photoplethysmograph and pressure transducer were chosen because their physical and electrical properties avoid several of the vulnerabilities encountered in other techniques for quantifying sexual response. The probe configuration minimizes motion artifact, permits comparison of the same sampling site across sessions and subjects, and quantifies the interaction between blood volume and varying contact pressure. Electrical signals are fed directly to a strip‐chart recorder and a dedicated real‐time computer system. Automatic analog‐to‐digital conversion of the original data avoids errors in manual extraction of analog data, maximizes precision in data analysis, and permits digital plotting to simulate higher or lower chart paper speeds. Configuration of a vaginal probe which utilizes the same transducer elements as the anal probe is also presented.
The Relationship of EDA to Electrode Size
Authors: Mitchell David A. , Venables Peter H. 
Published: February 2007

ABSTRACTThe pari passu relationship between contact area of electrode and SCLs and SCR amplitudes which is predicted on the basis of current electrical models of EDA was investigated in a series of experiments employing a wide range of commonly used contact areas: .017 to .786 cm2 (.15 to 1.0 cm diameter). Having systematically eliminated obvious methodological and procedural problems a nonmonotonic relationship remained. On the basis of these findings two recommendations were made: 1) the use of an intermediate size, .5 cm2 (.80 cm diameter), of electrode in recording EDA; 2) SCLs and SCR amplitudes should be reported in terms of actual electrode size rather than specific conductance units as previously suggested. No effect of electrode size was found for time‐based measures of EDA. Results are discussed in terms of practical implications.
The Effects of Operant Reinforcement Schedules on the Modification of Human Heart Rate
Authors: Hatch John P. 
Published: February 2007

ABSTRACTThirty‐six male students were instructed to raise or lower their heart rates (HRs) and were provided with one of three different schedules of HR biofeedback. Within each direction of control condition, subjects were exposed to continuous beat‐by‐beat visual feedback, no feedback, or feedback presented according to a variable ratio (VR) schedule. During 4 training sessions VR subjects received feedback of a randomly selected 100%, 75%, 50%, or 25% of their heartbeats. All groups significantly altered their HRs in the instructed direction. For HR speeding, VR feedback produced significantly faster HRs than did continuous feedback while the VR schedule was in effect. No significant differences in HR slowing performance occurred among the three slowing groups. Resting initial HR levels did not significantly affect either speeding or slowing performance.
The Acquisition of Autonomic Control Through Biofeedback: The Case Against an Afferent Process and a Two‐Process Alternative
Authors: Lacroix J. Michael 
Published: February 2007

ABSTRACTBrener has proposed a general theory of the development of voluntary control which offers as its focus an account of the process underlying the acquisition of control over autonomic responses. This account views the acquisition process as consequent to the development of the subject's ability to discriminate afferentation related to the response state to be produced and to his formulating an appropriate response image on the basis of this afferentation. The paper begins with an extensive review of biofeedback studies pertinent to the theory. This review yields little convincing evidence for Brener's views. Selected studies on the performance and the acquisition of motor skills and on the nature of the image are then examined. These suggest that the development of control of a response may rely primarily on efferent processes, with afferent processes playing, at most, a secondary role. A two‐process theory of the acquisition of autonomic control is then presented. The theory proposes that, in most instances, biofeedback training leads to autonomic control through a process consisting primarily in the identification of efferent behavioural programmes already within the subject's repertoire. The theory further proposes that an afferent acquisition process such as postulated by Brener may also underlie the development of autonomic control, but only under conditions where behavioural programmes effective in controlling the target response are either unavailable or inaccessible to the subject.
Multiple Late Positive Potentials in Two Visual Discrimination Tasks
Authors: Friedman David , Vaughan Herbert G. , Erlenmeyer‐Kimling L. 
Published: February 2007

ABSTRACTEvent‐related potentials (ERPs) were recorded from 30 adolescents during two versions of the continuous performance test (CPT). Task B involved more complex processing than Task A, because subjects were required to store and compare successive stimuli to determine if a target had occurred, while Task A required a simple match‐mismatch decision. This was corroborated behaviorally, with Task B producing greater error rate, longer reaction times, and greater reaction time variance than Task A.Principal Components Analysis (PCA) with Varimax rotation was performed separately on the signal (SIG) and non‐signal (NSIG) ERPs from each task to objectively verify the presence of multiple positive peaks which had been visually identified in the individual and grand mean waveforms. These PCAs yielded factor structures and “components” whose shapes, time courses and factor score topographies were similar across ERP subsets, suggesting that each might represent activity within the same brain region.Differences in these factors across data sets were also evident. To assess these, ANOVAs of the factor scores from the PCA performed on the ERPs pooled across stimuli and tasks were performed. Consistent between‐task effects were shown by P450, P550 and slow wave, potentials which appear to reflect processes related to the discriminative outcome.These data conclusively demonstrate the presence of multiple late positive components within the latency range of the classical P300 wave.
Normalizing Effects of Methylphenidate on Hyperactive Children's Vigilance Performance and Evoked Potentials
Authors: Michael Robin L. , Klorman Rafael , Salzman Leonard F. , Borgstedt Agneta D. , Dainer Karen B. 
Published: February 2007

ABSTRACTEvoked potentials during the × and B‐X versions of the Continuous Performance Test (CPT) were evaluated in 29 hyperactive children after ingestion of placebo or methylphenidate (0.3 mg/Kg). Twenty‐one age matched normal children were also assessed twice but without any drugs.In both tests, placebo‐treated hyperactives made more omission and commission errors and displayed smaller late positive components (LPC) of the evoked response to salient experimental cues. Methylphenidate ameliorated hyperactives’ performance in both tasks and enlarged their LPCs in CPT‐X. Several of these drug effects and diagnostic differences were absent for older hyperactive subjects, probably because some of the procedures were too easy for them. For younger patients the present tasks were sufficiently challenging, and the results reflect normalization of their deficits in sustained attention.
Sympathetic Nerve Activity Underlying Electrodermal and Cardiovascular Reactions in Man
Authors: Wallin B. Gunnar 
Published: February 2007

ABSTRACTThe paper summarizes results of micro‐electrode recordings of sympathetic activity in human muscle and skin nerves. The nerve activity was correlated with blood pressure, plasma noradrenaline, electrodermal and/ or plethysmographic activity. Baroreflex and thermoregulatory mechanisms were studied as well as effects of arousal or emotional stimuli.
Publication Recommendations for Electrodermal Measurements
Authors: Fowles Don C. , Christie Margaret J. , Edelberg Robert , GRINGS William W. , Lykken David T. , Venables Peter H. 
Published: February 2007

ABSTRACTThe paper recommends an acceptable methodology for recording electrodermal activity which reflects a consensus of experts in the field. These recommendations are presented with a minimum of technical discussion in order to maximize their usefulness to investigators who are not specialists in this area.For most purposes, skin conductance (SC) is to be preferred over skin potential (SP). It is recommended that SC be recorded from palmar sites with silver‐silver chloride electrodes and an electrode paste consisting of a sodium chloride electrolyte in a neutral ointment cream medium. The area of contact with the skin should be controlled and time allowed for stabilization of the skin‐electrode paste interface. Electrode bias potentials and polarization should be monitored during use. Signal conditioning is achieved by the application of a constant 0.5 volt across the electrodes and measurement of the resultant current flow by amplifying the voltage developed across a small resistor in series with the skin. The measurement of the amplitude‐or even the detection‐of small responses requires some form of tonic level control, permitting an adjustment of the tonic level. A circuit is provided for signal conditioning and tonic level control.SP can be recorded with the same electrodes and electrode paste, unless the results are to be related to the British work on SP level, in which case the original potassium chloride electrolyte in an agar medium should be used. SP recordings require that one of the electrodes be placed over an inactive reference site, preferably over the ulnar bone near the elbow. No external voltage is applied, but some form of tonic level control may be needed. Electrodes need to be checked for bias potentials but not polarization.
Selective Attention Effects on the Reflex Blink
Authors: Silverstein Louis D. , Graham Frances K. , Bohlin Gunilla 
Published: February 2007

ABSTRACTPast work has shown that facilitation of reflex blinking accompanies cardiac deceleration when the attention of subjects is directed to a reflex‐eliciting stimulus. The present studies showed that when warning stimuli directed attention instead to weak (tactile) stimuli presented simultaneously with reflex‐eliciting (acoustic) stimuli, cardiac deceleration was still present but reflex magnitude was unchanged or inhibited. However, latency to reflex onset remained facilitated, i.e., latency and magnitude changes were discordant. The findings were interpreted as evidence for two independent processes: a process capable of selectively enhancing or attenuating sensory input and a non‐selective process presumably facilitating motor pathways.
Heart Rate Discrimination Before and After Exercise‐Induced Augmented Cardiac Activity
Authors: Jones Gary E. , Hollandsworth James G. 
Published: February 2007

ABSTRACTAlthough there is little direct evidence available, there is a pervasive assumption that HR is easily detected during periods of physical stress or exertion. It has also been suggested that distance runners are keenly aware of their cardiac functioning. The present study assessed cardiac awareness while at rest and again following vigorous exercise for groups of subjects differing in physical fitness. Thirty‐six subjects were solicited and composed groups of Sedentary, Tennis, and Distance Running groups. Each group was composed of equal numbers of male and female subjects. HR awareness was assessed using 35 10‐sec discrimination trials. Veridical feedback was composed of light flashes triggered by EKG R‐spikes whereas false feedback was composed of flashes at rates 10, 20, or 30 percent above or below their actual rate. At the end of each trial, subjects indicated the degree of certainty of their choice. Discrimination accuracy was measured at rest and again following exercise which raised HR level by 75 percent. Analyses of variance indicated that male runners were significantly more accurate discriminators at rest than any other group. Similar superiority was not shown by the female runners. After exercise, the tennis and sedentary groups showed significant overall increases in awareness during augmented cardiac functioning. Exercise did not produce additional increments in awareness for the male runners. A battery of post experimental questionnaires largely failed to discriminate experimental groups.