bluuebunny/crossref_metadata_2025_split huggingface dataset:
Skeletal Muscular Patterning: Topographical Analysis of the Integrated Electromyogram
Authors: Cacioppo John T. , Marshall‐Goodell Beverly , Dorfman Donald D. 
Published: February 2007

ABSTRACTThe extraction of mean amplitude from integrated electromyographic (IEMG) responses provides a valid but limited measure of muscle action potentials (MAPs). More comprehensive topographical analyses of IEMG responses based on frequency analyses are unsatisfactory since IEMG responses are aperiodic, and autoregressive procedures may be unsatisfactory since autocorrelations constitute an irreversible transformation of the original waveform, represent a substantial loss of information in contrast to the original waveform, and harbor little apparent relationship to MAPs. In a Theoretical Investigation, a mathematical procedure is developed to quantify topographical features of both the amplitude and temporal dimensions of the IEMG response. Procedures for extracting these parameters and the relationship between each and the recruitment of MAPs are illustrated. In a Validation Study, surface electromyograms are recorded from the preferred forearm under various conditions of mild isometric forearm contraction. Results support the viability, reproducibility, and validity of the topographical analysis.
Task Difficulty, Heart Rate Reactivity, and Cardiovascular Responses to an Appetitive Reaction Time Task
Authors: Light Kathleen C. , Obrist Paul A. 
Published: February 2007

ABSTRACTCardiovascular responses of 72 young men were assessed during an appetitive reaction time task where winning money incentives was either easy, difficult, or impossible. The impossible condition led to reduced responses (e.g., longer pre‐ejection period (PEP) and pulse transit time (PTT) and greater falls in systolic and diastolic pressures) as well as reports of trying less hard than the easy or the difficult condition. Regardless of task difficulty, subjects showing greater heart rate (HR) increases at task onset maintained higher HR levels than low HR reactors throughout the task. Overall, these high HR reactors also showed higher SBP and shorter PEP, PTT and left ventricular ejection time than low HR reactors, although these differences were less pronounced by the end of the task. Based on their responses to various standardized inventories, high and low HR reactors did not differ in behavioral traits such as Type A, suppressed hostility, or active coping as the preferred coping style. However, a subsample of subjects with extreme scores indicating suppressed hostility (N = 12) did show elevated HR and systolic pressure during both relaxation and the appetitive task.
Type A Behavior and Psychophysiological Responses in Adult Women
Authors: Lawler Kathleen A. , Rixse Andra , Allen Michael T. 
Published: February 2007

ABSTRACTThe purpose of this study was to assess both coronary‐prone behavior and physiological responses to stress in adult women. Forty‐one women, aged 25–55, were tested; half were professional or executive‐level employed women, the remainder were housewives. Based on the Jenkins Activity Survey, the working women scored as strong Type A's; the housewife group contained both A's and B's. The heart rate, blood pressure and skin conductance responses were compared for these groups while they rested, performed math problems, and attempted to solve visual puzzles. Type A women showed higher heart rates and larger increases in systolic and diastolic blood pressure; Type B women showed larger phasic heart rate decelerations. Employment was not a prerequisite for increased cardiovascular responsivity in Type A's; however, the unemployed Type A's indicated a desire to work. Given the similarities between employment status, Type A behavior and physiological responses in these working women as compared to men, their risk for coronary heart disease may also be similar.
Cardiac and Metabolic Responses to “Space Invaders”: An Instance of Metabolically‐Exaggerated Cardiac Adjustment?
Authors: Turner J. Rick , Carroll Douglas , Courtney Hazel 
Published: February 2007

ABSTRACTHeart rate, plus various ventilatory and metabolic indices, were monitored while 24 male subjects played a computer game of the “space invaders” type and during a control condition, in which analogous but ineffective actions were requested and the game proceeded automatically. Relative to baseline, subjects showed much larger increases in heart rate during “space invaders” than during the control condition. However, oxygen consumption, carbon dioxide production, respiratory rate and volume also increased more. While the absolute magnitude of metabolic differences between conditions could be regarded as modest relative to heart rate differences, given the effective range of variations possible for each parameter, the existence of highly significant differences in oxygen consumption and carbon dioxide production militates against assertions of overall cardiac‐metabolic independence during “space invaders.” Nevertheless, analysis of individual differences in heart rate reactivity would seem to provide some evidence of metabolically‐unjustified heart rate changes during “space invaders.” High heart rate reactors during “space invaders” did not differ from low reactors in either oxygen consumption or carbon dioxide production. In addition, this relatively high heart rate reactivity was specific to the “space invaders” condition; high and low heart rate reactors displayed no differences in heart rate, or in any other physiological measure, during the control condition or during baseline.
Estimating Neonatal Oxygen Consumption from Heart Rate
Authors: Woodson Robert , Field Tiffany , Greenberg Reena 
Published: February 2007

ABSTRACTThe relationship between heart rate (HR) and oxygen consumption (V̇o2) has been investigated in a sample of 20 low‐risk, term neonates aged 14–48 hrs. Repeated, simultaneous measurements of HR and V̇o2 were performed on each neonate during each of three epochs ordered by increasing level of activity. A robust linear relationship was found between HR and V̇o2, with an average correlation of.90. Substantial variation was observed across individuals in the slope of the HR‐V̇o2 regression line. This variation was curvilinearly related to ponderal index (PI), with low PI neonates having the shallowest and steepest slopes. These findings suggest that HR may provide a flexible, non‐restrictive means of estimating neonatal V̇o2 but that the impact of prenatal growth history and postnatal growth performance on the estimation of V̇o2 from HR merits further investigation.
Effects of Water Temperature on Some Noninvasively Measured Components of the Human Dive Reflex: An Experimental Response‐Topography Analysis
Authors: Furedy John J. , Morrison James W. , Heslegrave Ronald J. , Arabian Jane M. 
Published: February 2007

ABSTRACTThe human dive reflex (DR) essentially consists of HR deceleration (HRD) and peripheral vasoconstriction. The dominant view of the DR's mechanism is (adaptive) oxygen conservation such that the DR is often referred to as the oxygen‐conserving reflex. However, this and other issues have not been resolved because the literature has lacked precise measurement quantification and experimental control. The present study was designed to test the oxygen conservation hypothesis in a controlled laboratory setting and varied temperature between three groups of 16 subjects (10°, 20° and 40° C). The range was chosen to produce maximal variation in the rate of trigeminal cold‐fibre activity, and minimal pain‐fibre activity. The response‐topography results were consistent with an earlier study, and also yielded evidence that the DR varied inversely with temperature. This seems contrary to the oxygen‐conservation view, and indirectly implicates the role of the trigeminal nerves in the afferent mechanisms of the human DR. A physiological analysis of these results is offered.
Systolic Blood Pressure and a Simple Reaction Time Task
Authors: Paller Ken , Shapiro David 
Published: February 2007

ABSTRACTCardiovascular changes during a reaction time task have been hypothetically related to the speed of response with implications for a close connection between the two, but little research has attempted to characterize the pressor response in this situation. In this study, continuous measures of heart rate, respiration, and systolic blood pressure (using a noninvasive tracking‐cuff system) were made in 12 subjects during a visually signalled reaction time task with a fixed foreperiod of 6 sec. Consistent and significant changes were shown over the course of the foreperiod–an increase in systolic pressure, a multiphasic pattern in heart rate, and a decrease in respiration amplitude. There was a nonsignificant increase in respiration rate. Correlations between response latency and various indices of physiological level and change during the foreperiod were low and nonsignificant. The changes in heart rate and systolic blood pressure during the foreperiod appeared independent of one another. Interrelationships between the physiological measures in their phasic and tonic changes, and the implications of the findings for cardiovascular‐behavioral interactions are discussed.
Stimulus Omission and Dishabituation of the Skin Conductance Response
Authors: Siddle David A.T. , Remington Bob , Kuiack Marg , Haines Erica 
Published: February 2007

ABSTRACTThree experiments investigated the effects on the skin conductance response of S2 omission following 15 S1‐S2 presentations. These effects were examined at omission and on the following S1‐S2 (re‐presentation) trial. In Experiment 1 (N = 36), S1 was a 5‐sec slide of a snake and S2 was 1 sec of either 65 or 105 dB white noise. The S1‐S2 interval was 4 sec. Both frequency and amplitude of omission responses were a positive function of S2 intensity, and responding to S2 re‐presentation was reliably higher than on the preomission trial. Experiment 2 (N = 36) used the same S1, an S2 of 105dB, and two additional groups which controlled for stimulus omission and spontaneous recovery. Omission of S2 again produced increased responding to its re‐presentation. In Experiment 3 (N = 72), S1 and S2 were moderately intense tones (80dB) and lights (1089 cd/cm2. The procedure for the experimental and two control groups was essentially the same as in Experiment 2, except that S1 modality was counterbalanced across subjects. The experimental group displayed significantly larger responses to S2 on the re‐presentation trial than the control groups regardless of its modality. The results are discussed in terms of theories of habituation with special emphasis on the concept of priming utilized by Wagner (1976) and Öhman (1979).
An Evaluation of Trait, State, and Reaction Aspects of Activation Processes
Authors: Fahrenberg Jochen , Walschburger Peter , Foerster Fritz , Myrtek Michael , Müller Wolfgang 
Published: February 2007

ABSTRACTPsychophysiology is traditionally concerned with certain “indicators” of activation (arousal, stress‐strain). The experimental investigation of general mechanisms of activation should, therefore, be supplemented by evaluating the assessment and predictability of individual differences in trait, state, or reaction aspects of activation. Male students (N = 125) were examined under five conditions (rest, mental arithmetic, interview, anticipation, and blood taking) on one psychological and seven physiological criterion measures of activation state and reaction. Five variables are assumed to be adequate predictors of substantial criterion variance: questionnaire scores for emotional lability, reported frequency of somatic complaints, physical capacity (O2 max during ergometer test), cardiorespiratory reactivity (during breathholding and cold pressor tests), and an explicit instructional set emphasizing or deemphasizing the importance of the experimental results. Statistical analysis by correlation and multiple regression procedures reveals that these dispositional variables fail to reliably predict individual differences in state and reaction parameters of activation processes.
Perceptual and Motor Space Representation: An Event‐Related Potential Study
Authors: Ragot Richard 
Published: February 2007

ABSTRACTThe purpose of this experiment was to study the brain potentials generated during spatial tasks related to the “schema corporel” (a mental map of sensory‐motor relationships). Seven right‐handed subjects performed a choice reaction‐time task (Experiment 1), in which the spatial position of a visual stimulus (right or left of a fixation point) was varied independently of the spatial position of the response (right or left hand). The subjects also made self‐paced extensions and flexions of the right and left index fingers (Experiment 2). Experiments 1 and 2 were performed with the hands both crossed and uncrossed.Spatio‐temporal maps showed that the P300 component elicited by the choice RT situation in Experiment 1 was largest ipsilateral to the hand involved in the response, whether or not the hands were crossed. The later part of the pre‐movement potentials during Experiment 2 and the motor potential were significantly larger contralateral to the moving hand under all conditions. Thus this pattern of lateralization can be attributed to the superimposition of a bilateral P300 wave on the asymmetrical motor potential. This suggests that distinct neuronal populations are involved in the generation of these two components.P300 latency and RT reflected the spatial conflict: both were longer when the stimulus and response were on opposite sides than when they were on the same side, even when the hands were crossed. However, the average P300 latency was not increased when the hands were crossed, whereas the average RT was substantially increased. Since the additional time required for programming the movement in the crossed hand situation had no effect on P300 generation, we infer that the P300 does not index this motor programming. However, P300 does reflect the stimulus‐response spatial matching, since its latency was delayed by spatial conflict.
Factoring the Coherence Matrix: Patterning of the Frequency‐Specific Covariance in a Multichannel EEG
Authors: Tucker Don M. , Roth David L. 
Published: February 2007

ABSTRACTCurrent methods in research on the electrophysiology of human information processing include high speed quantification of EEG signals from multiple electrodes. The data from each electrode comprise a time series, from which the frequency information can be extracted through Fourier analysis. A problem in this research is appropriately handling the large amount of data in such a way that the topographic patterning of the electrical activity can be related to differential usage of brain regions during specific forms of cognition. We illustrate how factor analysis can be applied to describe the regional patterning of covariance in the spectral information of a multichannel EEG. Rotated factors delineate distinct patterns of electrophysiological activity across the head. Coherence factors show good replicability over repeated observations, and lateralized effects of cognitive activity are observed in the factor loadings. Further applications of this method are discussed, including some suggestions relevant to applying confirmatory, hypothesis testing factor analyses.
Effects of Stimulation Rate and Attribute Cuing on Event‐Related Potentials During Selective Auditory Attention
Authors: Hansen Jonathan C. , Hillyard Steven A. 
Published: February 2007

ABSTRACTAuditory event‐related potentials (ERPs) were recorded from subjects who attended selectively to a sequence of tones of one frequency and ignored a comparable sequence of tones having a different frequency and spatial origin. In one condition the tones consisted of randomized sequences of brief tone pips while in a second condition the tones were brief increments in intensity (pedestals) of continuous tones at the two frequencies. The tone pips and pedestals were delivered at comparable interstimulus intervals (ISIs), which were short (250–550 ms) in some runs and long (1250–2750 ms) in others. For both classes of stimuli, the subject's task was to detect occasional “target” tones of a slightly shorter duration than the more frequent “standard” tones. Stimuli of the attended frequency elicited a broad negative ERP component (Nd) relative to the unattended tone ERPs. The Nd wave had a considerably shorter onset latency and was smaller in overall amplitude at the faster rate of stimulation. However, the Nd wave did not differ in latency or amplitude between the tone pip and pedestal conditions at corresponding ISIs, suggesting that a high rate of information delivery is a more important factor in accelerating Nd onset than is the continuous reinforcement of the sensory cues that define the two classes of input.
A Reexamination of Fear and Its Determinants on the Visual Cliff
Authors: Bertenthal Bennett I. , Campos Joseph J. 
Published: February 2007

ABSTRACTRichards and Rader (1983) argue in their recent Psychophysiology paper that crawling experience plays no significant role in the development of visual cliff performance, and also that “fear” is not related to the development of the avoidance of heights. It is our contention that these conclusions rest upon oversimplified assumptions about the nature of fear and its determinants on the visual cliff. A very different set of inferences emerge from an alternative conceptualization of the problem. In contrast to Richards and Rader, we argue that heart rate cannot be simply equated with fear but rather represents one of many loosely correlated indices. Evidence is presented to show that behavioral and cardiac responses converge to demonstrate fear of heights by locomotor infants. It is further argued that the role of crawling experience is not given an adequate test by Richards and Rader. The theoretically important test involves a comparison between locomotor and prelocomotor infants. Data from such comparisons are reviewed and found to support self‐produced locomotion as an important predictor of visual cliff performance.
The Effect of Modification of Baroreceptor Activity on Reaction Time
Authors: Toon Peter D. , Bergel Derek H. , Johnston Derek W. 
Published: February 2007

ABSTRACTThe Laceys' hypothesis that baroreceptor stimulation has a direct effect on performance was tested by experimental manipulation of baroreceptor activity while subjects performed reaction time tests. Baroreceptor activity was altered by varying external cervical pressure and hence carotid sinus transmural pressure. The physiological effects of the baroreflex on heart rate and pulse transit time (a measure which generally correlates well with blood pressure) were seen both when baroreceptor stimulation was increased and when it was decreased. However, no difference in reaction time was found between the two conditions, therefore failing to support the Laceys' hypothesis.
Effects of Methylphenidate on Young Adults' Performance and Event‐Related Potentials in a Vigilance and a Paired‐Associates Learning Test
Authors: Strauss Jaine , Lewis Jeffrey L. , Klorman Rafael , Peloquin Lori‐Jeanne , Perlmutter Richard A. , Salzman Leonard F. 
Published: February 2007

ABSTRACTTwenty‐two normal young men received a counterbalanced and double blind administration of 20 mg methylphenidate and placebo. Two tasks were administered in counterbalanced order: an uninterrupted 45‐min vigilance test and a paired‐associates learning test. As previously reported, under placebo, accuracy and speed decreased monotonically over the course of the vigil. This degradation of performance was significantly reduced by the stimulant drug. Event‐related potentials (ERPs) were derived for correctly detected targets and nontargets. The most salient pharmacologic effects involved a late positive wave (P464) identified as P3b. Methylphenidate reversed or reduced the decrease in amplitude and increase in latency of P464 present over phases of the placebo session. The results suggest that the stimulant‐induced improvement in performance may be mediated by enhancement of evaluation processes.In the paired‐associates test there were no pharmacologic effects. Instead there was an unexpected, pronounced improvement in learning in the second session, irrespective of the substance administered. However, the ERP evoked by the “stimulus” cue of each pair was systematically related to the achievement of learning criteria. A late positive was identified as P3b (P555) increased significantly in amplitude following the attainment of learning. There were no amplitude changes among ERPs evoked in the early post‐criterion, late post‐criterion, or overlearning “phases.” Nor were there amplitude changes between early and late pre‐criterion categories. Thus, ERP amplitude displayed a binary association with the achievement of learning.
Spectral Analysis of the Visual Evoked Potential (VEP): Effects of Stimulus Luminance
Authors: Jutai J.W. , Gruzelier J.H. , Connolly J.F. 
Published: February 2007

ABSTRACTPower spectral analysis was performed on the visual evoked potentials (VEPs) of subjects who had participated in an augmenting‐reducing study. Six flash luminances were used (0.31, 0.65, 1.25, 2.5, 5.0, and 10.0 fL). EEG recordings were taken from Cz O1, O2, T3, and T4 scalp locations. Power in six frequency ranges was examined (0–2, 2–6, 6–10, 10–14, 14–18, and 18–22 Hz). Power in the lowest three frequency ranges increased linearly with stimulus luminance at all electrode sites. Power in the highest three ranges increased linearly with luminance at occipital sites only. Power was greater in the left hemisphere than in the right for 18–22 Hz activity recorded at occipital locations. The reverse asymmetry occurred for 6–14 Hz activity recorded at temporal locations. The results suggest that individual differences in stimulus control in EEG recordings taken from scalp locations overlying nonspecific cortex are due primarily to the contributions of higher frequency components of the VEP spectrum. A thalamo‐cortical model of stimulus control is described.
Acquisition of Skeletal Conditioned Responses in Pavlovian Conditioning
Authors: Prokasy William F. 
Published: February 2007

ABSTRACTThere are four stages in the acquisition of skeletal responses when employing Pavlovian methodology: contingency detection, response selection, response acquisition, and response shaping. A two‐phase output model describes in detail the underlying response likelihood changes across the first three of the stages. Phase 1 of the model applies to the first two stages while Phase 2 applies to stage three. It was shown that Phases 1 and 2 are independent by virtue of the fact that shifts in the parameters of one are not necessarily correlated with changes in the parameters of the other and the fact that independent variable manipulations which affect one Phase do not necessarily influence the other. These results imply that there is no single, continuous underlying associative strength function across trials.