bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analyzing Event‐Related Potentials: The Utility of High and Low Pass Filtering in Improving the Relationship Between Various Amplitude Measures and Principal Components Analysis Factor Scores
Authors: Pritchard Walter S. , Brandt Michael E. , Barratt Eernest S. 
Published: February 2007

ABSTRACTThe present investigation sought to determine whether the relationship between event‐related potential (ERP) principal components analysis (PCA) factor scores and analogous waveform amplitude measures could be improved by high‐ and low‐pass filtering the waveforms at a suitable cutoff value. Visual oddball ERPs were submitted to a varimax‐rotated PCA performed on the variance/covariance matrix. Principal components corresponding to P300 and Slow Wave were obtained. In keeping with the fact that the variance/covariance PCA analyzes sources of variance around the grand mean waveform, the grand mean waveform was subtracted from each of the original waveforms, and baseline‐referenced amplitude measurements were then made of P300 and Slow Wave. P300 was measured both as the maximum positive peak between 275 and 425 ms, and as the average amplitude during that interval. Slow Wave was measured as the average amplitude during the interval 400–700 ms. The P300 measurements were then repeated after high‐pass filtering the difference waveforms at 2 Hz. Slow Wave measurements were repeated after low‐pass filtering at 2 Hz. The value of 2 Hz was chosen as giving a reasonable cutoff based upon estimates of the wavelengths of the two components derived from inspection of their respective factor loading vectors.The correlation between factor scores and amplitude measurements was .94 for unfiltered Slow Wave and actually declined slightly but significantly to .91 when the waveforms were low‐pass filtered. It would appear that Slow Wave factor scores emerging from a PCA can be fairly well approximated by a time‐band measurement algorithm, and that this approximation is not improved by low‐pass filtering. For both filtered and unfiltered measurements of P300, the amplitude/factor score correlation was significantly higher for the time‐band method than for the peak method. Further, high‐pass filtering at 2 Hz improved the time‐band/factor score correlation significantly from .62 to .75. This improvement is probably because the unfiltered measurements were tapping sources of variance due both to the higher frequency P300 component as well as a simultaneously active, lower frequency Slow Wave component. Theoretical implications of these findings are discussed.
Effects of Smoking on Vegetative Reactivity to Noise in Women
Authors: Woodson Phillip P. , Buzzi Roberto , Nil Rico , Báuttig Karl 
Published: February 2007

ABSTRACTMultichannel psychophysiological recording was used to monitor phasic stress reactivity to intermittent environmental noise bursts both before and after either real or sham smoking by women. Smoking induced heart rate acceleration, peripheral vasoconstriction, and increased pulse velocity. These tonic effects were accompanied by a suppression of noise‐induced tachycardia and a partial inhibition of noise‐induced vasoconstriction. Contrary to its activating effect on cardiovascular tonus, smoking lowered skin conductance amplitudes. Subjective stress to the successive noise bursts increased over time in the sham smokers but remained unchanged in real smokers, both prior to as well as after smoking. This lack of sensitization prior to real smoking may be a learned relaxation response based on anticipation. It was concluded that smoking not only shifts the tonus of vegetative functions but also partially stabilizes the system against external stress loads.
Effects of Stimulus Omission and Stimulus Novelty on Dishabituation of the Skin Conductance Response
Authors: Siddle David A. T. , Hirschhorn Tania 
Published: February 2007

ABSTRACTThe present experiment (N=64) examined the effects of stimulus omission and stimulus novelty on dishabituation of the skin conductance response. During the training phase, subjects received 15 S1‐S2 pairings. On trial 16, S2 was omitted for one group, replaced by an experimentally‐novel stimulus for a second, and replaced by an experimentally‐familiar stimulus for a third. The control group simply received a further S1–S2 pairing on trial 16. All groups received a further S1–S2 pairing on trial 17. Tone, white noise, light, and vibration served equally often as experimental events, and responses to S1 and to S2 on trial 17 constituted the data of primary interest. The data indicated that both stimulus omission and stimulus novelty on trial 16 produced dishabituation to S2 on trial 17, whereas presentation in an unexpected position of an experimentally‐familiar stimulus did not. The results are discussed in terms of the concept of priming.
Diastolic Blood Pressure and Heart Rate Biofeedback Training During Orthostatic Stress
Authors: Weipert Doris , Shapiro David , Suter Thomas 
Published: February 2007

ABSTRACTForty male college student volunteers were asked either to increase their diastolic pressure or their heart rate while sitting and during orthostatic stress (going from a sitting to a standing position), and half of them were also given second‐ to‐second visual feedback for the target variable. Systolic blood pressure was also continuously recorded. Comparisons were made between baseline and voluntary control conditions, and test trials were included to examine immediate carry‐over effects.With voluntary control instructions, substantial increases in tonic levels were obtained for the three cardiovascular variables in both sitting and postural change conditions. In general, the increases were significantly greater for feedback than for no‐feedback conditions. Phasic effects of feedback were also observed during postural change conditions: the blood pressure troughs and the heart rate peak occurred earlier with feedback than for instructions only. Immediate transfer effects were obtained in feedback conditions only.The results were discussed in terms of concomitant effects of somatic and cognitive activities. The distinctive feedback effects on the time course of the responses suggest that a precise analysis of response patterns is needed in selecting appropriate feedback methods in the management of orthostatic hypotension.
Proportional Jerk: A New Measure of Motion as Applied to Eye Movements in Sleep and Waking
Authors: Aserinsky Eugene 
Published: February 2007

ABSTRACTThe third derivative of motion or the change in the rate of acceleration (also known as jerk) is examined in terms of its applicability to the study of psychophysiological function. An algorithm of this third derivative is presented to show that jerk can be derived from the arithmetic difference of two slopes which constitute the portion of motion being differentiated. By modifying the algorithm, a new parameter termed “proportional jerk’ or PJ is formulated whereby one slope is measured relative to the other slope; this PJ provides information about the smoothness of movement without being influenced by the velocity as is the traditional jerk measure. A practical application of the PJ to waking saccades and REMs in 11 human subjects revealed that REMs are significantly “jerkier’ or less smooth than waking calibration eye movements. Whereas the waking eye movements had a well‐defined negative phase of the PJ, the REMs did not show such stereotypical behavior. This is in accord with previous work which showed that waking saccade velocity increases to a maximum and then decreases whereas REMs maintain their peak or near peak velocities for varying periods. It was suggested that PJ can be useful in detecting subtle temporal changes in the course of movements and may be used as a parameter of motion even when the absolute amplitude is unknown.
For Distinguished Early Career Contribution to Psychophysiology: Award Address, 1985
Authors: Johnson Ray 
Published: February 2007

ABSTRACTA model of P300 amplitude is proposed that reduces the many hypothetical constructs invoked to explain variations in P300 amplitude to three dimensions: 1) Subjective Probability, 2) Stimulus Meaning, and 3) Information Transmission. Evidence is presented to support the assertion that variables on the subjective probability and stimulus meaning dimensions have independent and additive contributions to overall P300 amplitude. The amplitude contributions of both of these dimensions, however, are modulated by a multiplicative relation with the proportion of transmitted stimulus information. Within each dimension, the fundamental experimental variables and their interrelations are specified. An example is presented to show how, by using an additive factors method, the respective amplitude effects of the probability and stimulus meaning dimensions can be separated. Supporting data are presented to show that the proposed model provides a reasonable and testable framework in which to conceptualize P300 results.
Effects of Arousal on Habituation of Electarodermal versus Vasomotor Responses
Authors: Goldwater Bram C. 
Published: February 2007

ABSTRACTWhile there is considerable evidence (hat habituation of electrodermal responses is retarded under conditions of heightened arousal, less work has been done on vasomotor responses. A few studies have, however, suggested that arousal has the opposite effect on vasomotor responses, producing an acceleration of habituation In this case. The present study compared skin conductance (SC) and finger pulse volume (PV) responses to a series of tone stimuli under conditions of “high arousal” (HA)‐where subjects were standing during testing‐and “low arousal” (LA)‐where subjects were seated. Tonic measures confirmed that the experimental manipulation was effective in raising SC level and nonspecific activity and lowering PV level in the HA relative to the LA condition. Significant Group (HA vs. LA) X Measure (SC vs. PV) interactions for response frequency and number of trials to habituation were consistent with the prediction that arousal exerts differential effects upon habituation in the two response systems. These data provide further challenges to theories based on unitary models of autonomic response mechanisms.
An Evaluation of Different Techniques for Removing Eye‐Blink Artifact from Visual Evoked Response Recordings
Authors: O'Toole Dennis M. , Iacono William G. 
Published: February 2007

ABSTRACTThis investigation compared four methods used to control eye‐blink artifact in visual evoked response (VER) recordings using the augmenting‐reducing paradigm: rejecting trials containing blinks, presenting the stimuli through closed eyelids, and two different techniques for subtracting a proportion of the averaged electro‐oculogram (FOG) from the averaged VER. The two subtraction procedures differed in the way in which they estimated the amount of EOG to be subtracted and in the case with which they could be applied. Twenty normal, female subjects were exposed to a series of four different intensity light flashes twice with eyes open and once with eyes closed. Blinking was monitored by recording the EOG and EEG was recorded from three midline electrodes. The results indicated that the two subtraction techniques were very similar. They effectively removed ocular artifact and produced corrected VERs that showed high retest stability. Presenting the flashes through closed lids yielded idiosyncratic data, and rejecting trials contaminated by blinks was found to have limited utility with the VER paradigm used in the present study.
Behavioural Energetics: Some Effects of Uncertainty on the Mobilization and Distribution of Energy
Authors: Brener Jasper 
Published: February 2007

ABSTRACTSeveral sets of data illustrating dissociation of metabolic and muscular work rates are presented. During response acquisition, the rate of energy expenditure declines although work rates remain constant and goal achievement increases. When higher response costs are demanded for goal achievement, work rates increase whereas energy expenditure remains constant. Decreases in outcome probability also give rise to increases in motor intensity and work rate but do not influence the rate of energy expenditure. It is proposed that behaviourally‐related variations in metabolic rate are influenced by environmental uncertainty (“what to do”), whereas variations in the intensity of motor output are influenced by response uncertainty (“how to do it”). The processes of response selection which provide the means by which response uncertainty is resolved, activate motor channels for the expression of energy mobilized by the prevailing state of environmental uncertainty.
A Passive Behavioral Measure of Sleep Onset in High‐Alpha and Low‐Alpha Subjects
Authors: Perry Thomas J. , Goldwater Bram C. 
Published: February 2007

ABSTRACTPolygraph recordings were conducted with normal subjects who were not sleep‐deprived lo examine the association between EFG alpha dynamics and a passive behavioral index of sleep/ wake status, and to assess the usefulness of that index in subjects who do not produce abundant wakeful alpha activity. I In‐ behavioral indicator of sleep unset comprised the depression of a telegraph key initialed by loss of extensor tension in the finger. Alpha abundant (high‐alpha) subjects showed a strong association of alpha level (as sleep Stage Wake (w) vs. Stage I sleep) with behavioral level, and a strong association of alpha loss events with key closure events. Mean latencies between alpha loss and key closure varied from ‐ 1.8 to 18.4 s with a median of 1.0 s. As expected, high‐alpha subjects also showed significant correlations between alpha level and changes in peripheral physiological variables in the vicinity of sustained alpha losses. Compared with Stage W. Stage 1 was associated with a greater incidence of slow eye movements, lower abdominal breathing amplitude, and a higher thoracic:abdominal breathing ratio. Similar correlations were observed in both high‐alpha and low‐alpha subjects between these variables and the key index, supporting its potential generality as an indicator of sleep onset.
The Sleeping Rat Shows Signs of Orienting Response to Neutral Stimuli
Authors: Johnen Marga 
Published: February 2007

ABSTRACTCortical arousal, cardiac response, and body movement to auditory stimuli were studied during slow wave sleep (SWS) of the rat. Rats were exposed to sequences of 10 tone pulses of a frequency of 16 kHz, a sound pressure level of 60dB, and n duration of 2 s (Experiment I) or 10 s (Experiment II). Repeated stimulus presentations permitted the evaluation of short‐term habitation. Similar results were found in both experiments, i.e. habitation of the cortical arousal response and of the phasic cardiac deceleration to stimulus onset and offset. With repeated presentations, cardiac acceleration showed a less regular course than cardiac deceleration and cortical arousal. Subsequently presented tone pulses of 80dB did not result in a recovery of the habituated response. Cardiac deceleration and cortical arousal on the one hand, and cardiac acceleration and motor activity on the other hand, were strongly correlated. The results are compared with human studies.
Heart Rate Acceleration and its Relationship to Total Serum Cholesterol, Triglycerides, and Blood Pressure Reactivity in Men with Mild Hypertension
Authors: Jorgensen Randall S. , Nash John K , Lasser Norman L. , Hymowitz Norman , Langer Alan W. 
Published: February 2007

ABSTRACTThis study investigated heart rate (HR) acceleration and its relationship to serum cholesterol, triglycerides, and blood pressure reactivity in a group of men with unmedicated mild hypertension. Each man's cardiovascular responses were monitored as he performed the Stroop Color Word Interference test and played the Pac Man Videogame. In comparison to their low HR accelerator counterparts, high HR accelerators manifested greater systolic and diastolic blood pressure responses during behavioral challenge. Moreover, high HR accelerators exhibited higher levels of serum cholesterol and triglycerides than low HR accelerators, even though these determinations were made from blood drawn during the clinic visit that preceded the clinic visit where cardiovascular reactivity was assessed. Heart rate acceleration and its positive association with serum lipids, as well as its role as a potential individual difference relevant to the profiling of persons at greater risk for the development of atherosclerosis were discussed.
Bilateral Electrodermal and Electrocortical Activity in Anticipation of Sensorimotor Tasks
Authors: Rockstroh Brigitte , Elbert Thomas , Lutzenberger Werner , Birbaumer Niels , Roberts Larry E. 
Published: February 2007

ABSTRACTThe present study investigated the relationship between lateralized sensorimotor activation and lateralized elevation of electrodermal activity. Within a two‐stimulus reaction time paradigm skin conductance responses (SCRs) were recorded from both hands, while subjects awaited and performed unilateral sensorimotor tasks. A tactile warning stimulus was applied 6 s prior to a tactile imperative stimulus either to the same or to the contralateral hand; the imperative stimulus was associated with a choice reaction time task.Task‐dependent lateral asymmetry with larger skin conductance responses contralateral to the involved hemisphere indicated contralateral facilitatory processes rather than inhibition. This asymmetry disappeared with repeated stimulation (across trials). Only right‐hand (left hemispheric) tasks proved to be sensitive to habituation.The asymmetry, recorded in slow brain potentials (SPs), assured that lateralized cortical processing was induced through the present experimental arrangement. The brain potentials specified the time course of lateralized processing, exhibiting larger late negative shifts at the precentral areas contralateral to the hand involved in the sensorimotor task and larger early negativity and a more pronounced positive evoked potential (late positive complex, LPC) contralateral to the hand stimulated by the tactile warning stimulus.
A Comparison of Additional Heart Rates During Active Psychological Challenge Calculated From Upper Body and Lower Body Dynamic Exercise
Authors: Turner J. Rick , Carroll Douglas , Hanson Jane , Sims Jane 
Published: February 2007

ABSTRACTHeart rate, oxygen consumption, and blood pressure were recorded while 22 young males performed a stressful mental arithmetic task and played a video game. Measurements were also made while subjects undertook two separate graded dynamic exercise tasks, an upper body and a lower body task. All measures changed as a function of psychological challenge, and during exercise heart rate and oxygen consumption changed as an orderly function of workload. For each subject, heart rate was plotted against oxygen consumption over the various workloads for each exercise task separately, thereby generating two regression lines per subject. In conjunction with oxygen consumption values during the psychological tasks, these regressions allowed the prediction of expected heart rate values during psychological challenge, and thus the computation of additional heart rate as the difference between actual heart rate and predicted heart rate. Actual heart rate during psychological challenge was substantially greater than predicted heart rate, i.e., there was considerable additional heart rate. This was the case irrespective of whether upper or lower body exercise was used to compute the predictions, and there was no significant difference between the additional heart rates generated from the two exercise tasks, which produced regression lines with similar slope and intercept values.
Novel Approaches to the Problem of Latency Jitter
Authors: Möucks Joachim , Köuhler Walter , Gasser Theo , Pham Dinh Tuan 
Published: February 2007

ABSTRACTThis paper deals with the issue of variable latencies of single potentials. A new method is proposed for obtaining estimates of single latency shifts, which allows furthermore a statistical test on the presence of latency jitter. In the Appendix, we give a precise description of the algorithmic procedure in order to allow an implementation of the new approach. A simulation study using real data from 41 children demonstrated that the procedure performed much better than the familiar Woody algorithm which produced highly unstable estimates. The new statistical test on presence of latency jitter was validated and also evaluated using simulations. The test was specifically sensitive to latency jitter but not to other types of variation of single potentials. In an application of real flashevoked potentials evidence for the presence of variable latencies was found.
Computerized Cardiovascular Monitoring: Method and Data
Authors: Linden Wolfgang , Estrin Ronald 
Published: February 2007

ABSTRACTThis paper describes the development of a digitized, real‐time, microcomputer‐based signal processing system which records the following variables: systolic and diastolic blood pressure, heart rate, pulse transit time, blood volume pulse, and R‐, S‐, and T‐wave amplitudes of EKG signals. Forty‐eight healthy subjects participated in a three‐task stress response study in order to gather initial data for evaluating the reliability and validity of this monitoring system. The three tasks represented replications of earlier studies: 1) reading aloud of a monotonous neutral text (Reading Only, RO); 2) mental arithmetic without vocalization (Arithmetic Quiet, AQ); and 3) mental arithmetic with vocalization (Arithmetic Aloud, AA). The findings provided support for the reliability and validity of the new monitoring system given that few data were lost, and resting values as well as differential task responses were found to be comparable with earlier data sets derived via similar experimental protocols.
Relation of Learned Heart Rate Control to Self‐Report in Different Task Environments
Authors: Williams Robert J. , Roberts Larry E. 
Published: February 2007

ABSTRACTA widely‐expressed view based on early studies of the verbal report in biofeedback holds that response awareness is unnecessary for learned control of visceral responding. However, more recent evidence has questioned this view. This article reports two experiments that analyzed verbal reports with the methods of recent studies while examining procedural differences between early and recent research. Experiment 1 assessed the effects of bidirectional versus unidirectional training on heart rate control and self‐report. Experiment 2 examined heart rate control and self‐report in two task environments that differed with regard to whether somatomotor action was afforded or allowed. No instances of response learning without response awareness were observed in either experiment, even when task environments approximating those of the early biofeedback studies were used. The results support viewpoints of biofeedback that assign a role to response awareness in the development of instructed control.
Brown and Eccles' Depiction of Vagal Effects: An Old and Widely Used Method Reexamined
Authors: Velden Manfred , Karemaker John M. , Wolk Christoph , Schneider Roland 
Published: February 2007

ABSTRACTIt can be shown that the procedure for representing the effect of the vagal innervation of the heart introduced by Brown and Eccles in 1934 distorts the actual course of the inhibitory effect. A corrected procedure is proposed. It is stressed that cycle phase specificity of the stimulation can be studied only by drawing different curves representing the course of the vagal effect for different times of stimulation within the cardiac cycle.