bluuebunny/crossref_metadata_2025 huggingface dataset:
Classically Conditioned Blood Pressure Decreases Induced by Electrical Stimulation of Posterior Lateral Hypothalamus in Rabbits
Authors: Brickman Andrew L. , Schneiderman Neil
Published: February 2007

An experimental group of 5 rabbits received 5 acquisition sessions during which repeated presentation of a 550 Hz tone for 10 sec as the conditioned stimulus (CS) was always followed immediately by 25 pulse per sec, 10 sec train‐duration stimulation of the posterior lateral hypothalamus as the unconditioned stimulus (US). A control group of 5 rabbits received random presentations of the CS and US. The unconditioned responses (URs) to intracranial stimulation consisted of tachycardia and a depressor response; conditioned responses (CRs) consisted of depressor responses unaccompanied by systematic changes in heart rate. Neither systematic heart rate nor blood pressure responses occurred to the CS in the control group.

The present results contrast with those of previous studies in rabbits in which higher frequency, shorter pulse‐train hypothalamic stimulation as US induced a pressor response and reflexive bradycardia as URs, and bradycardia unaccompanied by blood pressure changes as CRs. It is concluded that hypothalamic stimulation as US permits more than one cardiovascular response pattern to be studied under controlled conditions during classical conditioning.
Effect of EMG Biofeedback and Progressive Muscle Relaxation Training on Awareness of Frontalis Muscle Tension
Authors: Sime Wesley E. , DeGood Douglas E.
Published: February 2007

Awareness of muscle tension, as estimated by a modification of the Kinsman et al. (1975) procedure for determining probability of correct estimation (P(c)) of absolute differences in muscle tension between adjacent trials, was examined before and after volunteer subjects underwent 4 sessions of either: 1) EMG biofeedback (BF) training, 2) progressive muscle relaxation (PMR) training, or 3) a placebo‐control (MC) procedure which involved listening to music as an alleged guide for relaxation. The subjects were 30 females (mean age = 28.3 yrs) responding to an offering of experimental treatment for anxiety and tension. Measurements of frontalis muscle tension (EMG) and P(c) were made before and after training. The results showed that EMG was significantly reduced by BF and PMR training but not by the MC procedure. Increases in P(c) after training were significantly greater for BF than for PMR or MC training. There were no group differences for subjective report of tension. Correlations between pre‐ to post‐training EMG and P(c) change scores were significant only for the BF group and the combined group of BF and PMR subjects. These results suggest that: 1) both BF and PMR training were effective in producing frontalis EMG reductions, 2) the following relationship may exist among training groups in terms of relative influence upon awareness of tension—BF training > PMR training > MC training, and 3) awareness of tension appears to be related to the ability to reduce EMG although the exact nature of this relationship remains unclear.
Event Related Potentials of Brain (CNV and P300) In A Paired Associate Learning Paradigm
Authors: Peters Jon F. , Billinger Thomas W. , Knott John R.
Published: February 2007

Cortical electrical activity as reflected by CNV and P300 was examined in paired associate learning and discriminative reaction time paradigms. The CNV amplitude following the first of a pair of trigrams showed an inverse relationship to acquisition; P300 amplitude increased monotonically. Amplitude of both waveforms was larger in the central‐parietal area than the frontal area in the paired associate learning paradigm, while in the discriminative reaction time paradigm CNV was maximal in the frontal area and P300 was maximal in the parietal area. The CNV data are interpreted as reflecting early arousal and attentional processes, whereas P300 may reflect the subject's decision about the relevance of the stimulus.
Oxygen Consumption and Ambulation During Operant Conditioning of Heart Rate Increases and Decreases in Rats
Authors: Brener Jasper , Phillips Keith , Connally Samuel R.
Published: February 2007

Using a shock‐avoidance procedure, large discriminated increases and decreases in mean heart rate (HR) were conditioned respectively in two groups of free‐moving rats. Accompanying the conditioned HR responses were equally significant variations in Oxygen Consumption and Ambulation indicating a nonspecific effect of the experimental contingencies. Ambulation and Oxygen Consumption were found to be correlated in some but not all experimental conditions. Thus, partial indices of somatomotor activity may not provide an adequate reflection of variations in general activity (energy consumption) and therefore may not be employed to draw meaningful conclusions regarding the integration of cardiac and somatomotor processes. Discriminated HR responses were acquired more rapidly by subjects in the Increase condition than by subjects in the Decrease condition. However, the latencies of the discriminated HR changes were considerably longer for the Increase than for the Decrease subjects. An unexpected result was that 5 of the 6 Decrease subjects developed profound bradycardic arrhythmias. These arrhythmias were under strong stimulus control and were exhibited only during a stimulus (SD) signalling that the reinforcement contingencies were in effect.
Development of a Neuromuscular Blocking Procedure for Heart Rate Conditioning in Immobilized Pigeons
Authors: Migani‐Wall Sandra A. , Cabot John B. , Cohen David H.
Published: February 2007

Pharmacological neuromuscular blockade has been used for some years in behavioral experiments to eliminate somatomotor responding. However, such blockade has other pharmacological actions, particularly on the autonomic nervous system, that confound its use in such experiments. The present study develops an immobilization procedure for the pigeon that allows heart rate conditioning with acquisition rates and response dynamics equivalent to those of non‐immobilized animals. Part I describes preliminary screening of four classes of blocking agents: curariform, depolarizing, steroidal, and a blocker of excitation‐contraction coupling. None alone were satisfactory in inducing and maintaining immobilization free of undesirable cardiovascular effects. However, these experiments led to a promising regimen in which immobilization was induced with pancuronium bromide and maintained with pancuronium and gallamine triethiodide. Part II describes this regimen and presents conditioning data showing that, for a majority of immobilized animals, conditioned heart rate change differed in no respect from that of non‐immobilized controls. Moreover, there were no differences between immobilized and non‐immobilized sensitization groups, and baseline heart rates neither differed among groups nor changed over training.
Electromechanical Switching of Preamplifier Input Leads: A Method of Increasing the Usefulness of Electrophysiological Recording Instruments
Authors: Milligan W. Lloyd
Published: February 2007

Experiments involving electrophysiological recording frequently consist of a trial interval during which a response is measured and a longer duration intertrial interval during which the response returns to its tonic level. If it is not necessary to record a response during the intertrial interval, the recording instrument is wasted during this time. This article describes a circuit which permits automatic switching of input leads so that responses can be recorded from more than one set of subjects sequentially. This arrangement results in more efficient utilization of laboratory instrument resources. An increase in data is obtained at minimal cost.
Extraversion and Individual Differences in Auditory Evoked Response
Authors: Stelmack Robert M. , Achorn Edwin , Michaud Aurelda
Published: February 2007

The auditory evoked response to low (0.5K Hz) and high (8.0K Hz) frequency tones at three levels of intensity (40, 55, and 80 dB) were recorded for subjects differing in degree of extra‐version. Introverts were observed to have greater N1‐P2 amplitude than extraverts with the low frequency tones at 55 and 80 dB intensity. The results support Eysenck's general proposal relating introversion to higher levels of cortical activity.
Effects of Alpha Feedback Training on Occipital EEG, Heart Rate, and Experiential Reactivity to a Laboratory Stressor
Authors: Chisholm Ronald C. , DeGood Douglas E. , Hartz Mary A.
Published: February 2007

The intent of this study was to examine whether brief alpha biofeedback training would alter the degree of physiological and experiential stress evidenced in an aversive laboratory situation. While occipital alpha and heart rate were monitored, 36 subjects underwent 8 presentations of a warning tone preceding fingertip electric shock by 30 sec. Subjects were then placed into one of three treatments taking place in dim light with eyes open. Group 1 received 24 min of contingent feedback. Group 2 received an equivalent amount of non‐contingent feedback and Group 3, a no‐feedback control condition, listened to music. Following the treatment period, 12 additional tone‐shock pairings were presented, equally divided between eyes‐open and eyes‐closed trials, also with and without continuation of the treatment period “signal” (i.e. contingent, non‐contingent feedback, or music). The results revealed that, in general, enhanced alpha density was maintained by the contingent feedback group during the post‐treatment aversive situation. However, the reduction in alpha suppression was not systematically accompanied by corresponding heart rate and self‐report reductions in situational reactivity. It was concluded that alpha feedback training was not sufficient to produce a generalized relaxation to the aversive situation. Alternative accounts of the results, focusing primarily on independence of response systems, are discussed.
The Psychopath and the Lie Detector
Authors: Lykken David T.
Published: February 2007

The article by Raskin and Hare (1978) asserts or very plainly implies that: 1) the control question lie test is extraordinarily accurate; 2) that this high accuracy can be achieved by objective scoring of the polygraph charts; 3) that the theory of this test is psychologically reasonable and was confirmed by the experiment reported; 4) that subjects give qualitatively different autonomic responses when lying than they do when telling the truth; and 5) that the experiment described shows that psychopaths can no more “beat” the lie detector than non‐psychopaths. All of these socially important claims or implications are critically examined and all of them are found to be untenable.
Autoregressive Spectral Estimates of Newborn Brain Maturational Level: Classification and Validation
Authors: Crowell David H. , Kapuniai Linda E. , Jones Richard H.
Published: February 2007

In order to examine the reliability and validity of classification of EEG maturational levels, brain activity before and after peripheral sensory stimulation was measured in two groups of full‐term newborn infants (N=50 and 48). Autoregressive coefficients from two derivations (C‐A, O‐A) were classified by means of logistic discrimination relative to three age groups: a low birthweight group of less than 35 weeks gestational age, a comparable two‐day‐old group, and a group 6 weeks to 3 months of age. Results demonstrated that EEG maturational level of two‐day‐old full‐term neonates can be reliably and validly classified. Autoregressive spectral analysis may function as a major technique for the hypothesis testing and classification of infant EEG.
Auditory Brainstem Recovery Processes From Birth to Adulthood
Authors: Salamy A. , McKean C. M. , Pettett G. , Mendelson T.
Published: February 2007

Two treatments‐by‐subjects with repeated measures experiments were performed to determine maturational changes in the recovery processes along the classical auditory pathway.

Subjects ranged in age from birth to adulthood. Brainstem evoked potentials (BEPs) recorded from the surface of the scalp were obtained at stimulus presentation rates of 10–40/sec for all subjects. In addition, some newborns and adults received repetition rates of 50–80/sec.

The amplitude and latency of selected BEP components which reflect discrete levels of brainstem integration, were measured. At stimulus rates of 10–40/sec strong age and rate effects evinced but significant interactions emerged only for those waves representative of rostral brainstem activity. A test of trend revealed that the newborns, in comparison with all other age groups, displayed slower recovery to increasing rates of stimulation (10–40/sec). The differential response of the individual BEP components conforms to the known caudo‐rostral maturation of the brainstem.

Stimulus rates above 50/sec (50–80/sec) produced a relatively uniform depression (refractoriness) in the early BEP components irrespective of age. Only potentials generated in rostral structures continued to covary with rate of stimulation.

These studies indicate that in the human brainstem the mechanisms responsible for neuronal recovery are essentially mature in the neonatal period.
Background Noise Levels and Heart Rate Orienting: Response Detection Using Time Series Analysis
Authors: Lobstein Tim , Webb Bob , Cort Janet
Published: February 2007

The purpose of this paper is two‐fold. The first is to introduce a method of analyzing single trials of beat‐to‐beat heart rate in adult subjects, by which significant changes in heart rate following a stimulus may be detected. The second is to demonstrate the economy of this form of analysis by presenting it in the context of a small‐scale experiment. The experiment examined heart rate orienting responses to a standard auditory signal, comparing the effects of high and low continuous background noise. The higher background noise level was found to enhance the accelerative component of the heart rate response to auditory signals.
Prestimulus Effects on Human Startle Reflex in Normals and Schizophrenics
Authors: Braff David , Stone Claudia , Callaway Enoch , Geyer Mark , Glick Ira , Bali Likh
Published: February 2007

Graham (1975) demonstrated that a weak prestimulus could effectively inhibit or facilitate the eyeblink component of the startle reflex in humans, depending on the temporal duration of the prestimulus. This study had three goals: 1) to replicate the findings of Graham, 2) to establish the reliability of this phenomenon by a test‐retest comparison, and 3) to compare the eyeblink reflex response of normal subjects with schizophrenic subjects. Seven prestimulus durations of continuous tone (from 0 to 2000 msec) were presented to 20 normal subjects and the results confirmed that maximal inhibition of eyeblink amplitude occurred in the 120 msec prestimulus condition. Increased amplitude occurred nonsignificantly when the prestimulus lasted for 2000 msec. On retest, 14 normal subjects showed a significant degree of reliability. When 20 normal subjects were compared to 12 schizophrenic subjects, significant differences in eyeblink response were found for blink amplitude and latency in the 60 msec prestimulus condition. This change is consistent with information processing “overload” theories of sensory overstimulation in schizophrenia. The blink reflex is a rather stable phenomenon and is probably altered in schizophrenia and/or by antipsychotic medication.
Reactivity to Heteromodal Stimulation as a Function of Stimulus Intensity and Inner Arousal
Authors: Alexander Robert , Epstein Seymour
Published: February 2007

In a preliminary study, it was observed that when increasingly intense light stimuli were presented simultaneously with a loud noise, magnitude of the skin conductance response increased over the first three levels of increasing light intensity, and then exhibited a paradoxical decrease. The present study extended the previous one by adding more intense stimuli and by examining the influence of inner sources of arousal in the form of motor effort and tonic skin conductance. Twenty subjects, half of whom squeezed a dynamometer during stimulus presentations, were presented with four intensities of noise combined with four intensities of light in all combinations in a randomized Latin Square design. Compared to the previous study, an increase in paradoxical responding was observed. However, the results could not be interpreted by simply assuming a reflexive inhibitory response to high levels of total stimulation. Rather they suggested the occurrence of what we have referred to as “intensity learning,” which involves a selective diminution in reactivity to high intensity stimuli while reactivity and alertness are retained to low intensity stimuli.
Coronary‐Prone Behavior Pattern and Cardiovascular Response
Authors: Manuck Stephen B. , Craft Suzanne , Gold Kenneth J.
Published: February 2007

Two studies were carried out examining the relationship between coronary‐prone behavior pattern and cardiovascular responses to an experimental stressor. Among 52 subjects of the Type A (coronary‐prone) and Type B (non‐coronary‐prone) behavior patterns in Study I, Type A males showed greater elevations of systolic blood pressure than Type B males on exposure to a difficult cognitive task; no reliable differences were found for Type A and B females. Due to a conceptual similarity of the coronary‐prone behavior pattern and the personality dimension of Internal External locus of control, 48 male subjects in Study II were selected with respect to four subject groups: Type A‐Internals, Type A‐Externals, Type B‐Internals, and Type B‐Externals. Again, Type As showed a more pronounced systolic response than subjects of the Type B pattern, though diastolic blood pressure and heart rate responses did not vary by coronary‐prone behavior pattern. While locus of control‐Internals tended to show greater task‐related systolic elevations than Externals, this effect was not significant. Self‐reports of anxiety increased during the period of the task, but revealed no differences among Type A and B subjects of either study. It was concluded that for male subjects the Type A‐Type B dimension constitutes a salient variable of individual differences mediating the systolic pressor response.
The Distribution of Attention Across Auditory Input Channels: An Assessment Using the Human Evoked Potential
Authors: Hink Robert F. , Fenton Wayne H. , Pfefferbaum Adolph , Tinklenberg Jared R. , Kopell Bert S.
Published: February 2007

In order to determine the extent to which distraction disrupts performance when attention is divided, the distribution of attention across five auditory input channels was assessed using the N1 component of the human auditory evoked potential. In addition, the possibility that methylphenidate (Ritalin) affects the distribution of attention across input channels was tested. Sixteen subjects performed a tone discrimination task under conditions of focused attention and divided attention, both with and without the presence of stimuli interposed between the points to be attended. The subjects performed in two sessions during which they received either methylphenidate (10 mg) or a placebo in a double‐blind design. The results showed that the interposed stimuli were receiving some attention resulting in a disruption of performance. Methylphenidate did not affect the distribution of attention as reflected in the N1 wave. The data are interpreted as showing that: 1) distraction plays a major role in producing performance deficits observed with divided attention; and 2) methylphenidate does not appreciably affect the distribution of attention across input channels.
Overhabituation and Dishabituation Responses as a Function of Stimulus Intensity and Amount of Overhabituation Training
Authors: Smith Barry D. , Council James
Published: February 2007

Several important issues regarding overhabituation and its effects have been raised. Of particular interest are the effects of amount of overhabituation on responses during overhabituation, the existence of important individual differences in response frequency and amplitude during overhabituation, and the effect of varied amounts of overhabituation training and of stimulus intensity on test and dishabituation response amplitudes. In the present study, each of 108 subjects was randomly assigned to one of three overhabituation exposure conditions (60, 120, or 180 trials) and one of two auditory stimulus intensities (60 or 85 dB). After reaching a phasic electrodermal habituation criterion, each subject received the appropriate number of overhabituation presentations of the standard stimulus (SS), followed by a test stimulus and an additional SS (the dishabituation stimulus). Results showed significantly higher frequencies and amplitudes of electrodermal responses to tonal stimuli with increasing numbers of overhabituation trials, but no significant changes over trial blocks. Individual differences were found. Subjects in a group defined by numerous overhabituation responses showed slower habituation, larger responses and higher frequencies of nonspecific responses during overhabituation, and larger test responses. Finally, the amplitude of test responses increased with increasing length of overhabituation and with increased intensity.
Electrodermal Indices of Stress and Cognition: Possible Hydration Artifacts
Authors: Bundy Robert S. , Mangan Steven M.
Published: February 2007

The study was designed to examine the relationship between electrodermal frequency (EF) and skin conductance level (SCL) in a paradigm that has previously demonstrated that these measures can operate independently. Electrodermal activity was recorded during 3 10‐min periods. All subjects rested during the first and last periods. Half of the subjects rested during the second period, and half were in a shock‐threat condition. Between the second and third periods a fresh electrode set was applied, and the subjects either inflated a balloon, operated a pursuit rotor, or were interviewed. Both measures were low for the rest periods and high during the shock‐threat condition except during the last rest period when SC was unexpectedly high, thus replicating previous research. However, application of new electrodes in the last period demonstrated that this high SCL was due to a time dependent effect, probably hydration, and was not due to the differential effects of stress and cognitive activity on the two electrodermal measures.
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

It 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

This 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

Vaginal 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

In 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

Increasing 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

The 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

The 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

Previous 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

A 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

The 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

Thirty‐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

Brener 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

Event‐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

Evoked 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

The 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

The 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

Past 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

Although 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.
The Production of Specific Decreases in Interbeat Interval and the Molor Skills Analogy
Authors: Johnston Derek W. , Lethem Jane
Published: February 2007

Johnston (1977) has argued that studies ofthe self‐control of heart rate have not provided clear support for thetheor that biofeedback aided leaming is analogous to a motor skill. This could be because the tasks studied are not modelled closely enough on the skills analogized and because feedback might aid control rather than leaming. These possibilities were examined in a series of five studies on decreasing interbeat interval (i.e. increasing heart rate) by a specific amount. It was shown in two studies that analogue feedback was superior to binary. The effect of frequency of feedback was weaker but frequent feedback was better than infrequent in two out of three studies. Feedback plus verbal instructions was better than verbal instructions alone and performance deteriorated when feedback was withdrawn. The results support the view that heart rate control does resemble a motor skill when the task set the subject has close similarity to a conventional skilled task and that, under these circumstances, feedback primarily aids performance and not leaming.
The Topography of Event‐Related Slow Potentials During Reflex Movement (Ankle Jerk) Conditioning
Authors: Ragazzoni A. , Bruneau N. , Martineau J. , Roux S. , Lelord G.
Published: February 2007

The morphology and scalp distribution of slow negative potentials elicited in type I conditioning, requiring no instruction, were studied. The paradigm involved the presentation of a conditioned stimulus (S1), followed 1500 msec later by an unconditioned stimulus (H), the electrical stimulation of the popliteal nerve evoking an ankle jerk (Hoffmann reflex).

Our topographical data showed that two components develop in the interstimulus interval S1‐H: a large fronto‐central early component followed by a late centro‐parietal negative component which precedes the H‐reflex movement. This negative shift terminates abruptly in a positivity post‐H‐reflex.

These anticipatory components show similarities, particularly at the parietal site, to slow waves elicited in a CNV paradigm involving the presentation of an indicative stimulus (S1) followed by an imperative stimulus (S2) requiring an operant motor response.

These results are discussed in terms of conditioning, arousal, and early preparatory and time estimation processes.