bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hostility Patterns and Cardiovascular Reactivity to Stress
Authors: Houston B. Kent , Smith Matthew A. , Cates David S. 
Published: February 2007

ABSTRACTSixty male subjects performed two challenging tasks while systolic blood pressure, diastolic blood pressure, and heart rate were monitored. They also completed the Cook and Medley Hostility Scale and measures of social support and mode of anger expression. Subgroups of subjects who differed in the patterns of their responses to the hostility items were identified via cluster analytic techniques. Exaggerated reactivity in systolic blood pressure to the two experimental tasks was exhibited by subjects in a subgroup who appear to have negative feelings toward people, but disavow these feelings and inhibit aggression so as not to alienate others. However, these individuals may have difficulty concealing their view of others and controlling their anger which, in turn, may erode their social support.
Effects of Beta‐Adrenergic Activity on T‐Wave Amplitude
Authors: Contrada Richard J. , Krantz David S. , Durel Lynn A. , Levy Linda , LaRiccia Patrick J. , Anderson Judith R. , Weiss Theodore 
Published: February 2007

ABSTRACTThis study addresses the hypothesis that electrocardiographic T‐wave amplitude is influenced by beta‐adrenergic stimulation of the heart. Beta‐adrenergic activity was manipulated both pharmacologically and through behavioral challenge. Under resting conditions, 12 healthy men underwent infusion of placebo and then the beta‐agonist, isoproterenol, and the beta‐blocker, propranolol, in a counterbalanced, crossover design. During infusion of placebo, subjects also underwent two behavioral challenges, a structured interview and mental arithmetic. Analysis of the resting data indicated that propranolol produced a significant increase in T‐wave amplitude, and isoproterenol produced significant T‐wave amplitude attenuation. As previously reported, drug effects were also in evidence for heart rate. Behaviorally‐induced reduction of T‐wave amplitude was observed for mental arithmetic but not structured interview, which again paralleled heart rate data. Both pharmacological and behavioral data reported in this study support the hypothesis that the T‐wave is significantly affected by beta‐sympathetic influence on the heart. However, a nonspecific effect of heart rate change on T‐wave amplitude would also account for these results. The findings are discussed in terms of their implications for the utility of T‐wave amplitude in psychophysiological research.
Attention to Color: An Analysis of Selection, Controlled Search, and Motor Activation, Using Event‐Related Potentials
Authors: Wijers Albertus A. , Mulder Gijsbertus , Okita Tsunetaka , Mulder Lambertus J.M. , Scheffers Marten K. 
Published: February 2007

ABSTRACTIn this study the organization of information processing in a selective search task was examined by analyzing event‐related potentials. This task consisted of searching for target letters in a relevant (attended) color. The ERPs revealed two different effects of attention: an early occipital negativity (± 150 ms) reflecting feature‐specific attention, and a later, central N2b component (± 240 ms) reflecting covert orienting of attention. A later, prolonged negativity (search‐related negativity) (± 300 ms), maximal at Cz, was related to controlled search to letters in the attended color. Detection of relevant targets resulted in a parietal P3b component. Depending on stimulus presentation conditions an earlier response to both attended and unattended targets was found: an N2 component (± 250 ms). In these same conditions, C3‐C4’ asymmetries (Corrected Motor Asymmetries–CMA) suggested motor activation at ± 300 ms, in the same time range as search‐related negativity. It was argued that N2 and CMA suggest the existence of a preattentive target detection system, operating in parallel with a slower serial attentive system, as reflected by N2b and search negativity.
The Effect of Lateral Visual Fixation and the Direction of Eye Movements on Heartbeat Discrimination
Authors: Weisz Jüalia , Baláazs Låaszlö , Láang Eszter , ÁDám Gyöurgy 
Published: February 2007

ABSTRACTThis study was undertaken to determine whether the asymmetrical activation of the two cerebral hemispheres affects the accuracy of heartbeat perception. Hemispheric preference—the tendency to activate one hemisphere rather than the other—was assessed by the directionality of conjugate lateral eye movements. Actual differential hemispheric activation was achieved by contralateral visual fixation. The results of 44 right‐handed male subjects showed that right hemisphere preferent subjects (“left‐movers”) performed better on a heartbeat discrimination task than left hemisphere preferent subjects (“right‐movers”). The direction of lateral visual fixation also influenced heartbeat discrimination: subjects fixating to the left were more accurate than those fixating to the right.
Cardiopulmonary Adjustments During Operant Heart Rate Control
Authors: Hatch John P. , Borcherding Steve , Norris Lea K. 
Published: February 2007

ABSTRACTTwenty‐three healthy men and women participated in a 5‐session experiment in which they attempted to increase and decrease their heart rate with the assistance of visual analogue biofeedback. As a group subjects did successfully raise and lower heart rate from resting baseline. These changes in heart rate were closely paralleled by changes in V̂, a measure of cardiac vagal tone. Heart rate slowing was associated with increases in V̂, and heart rate speeding was associated with decreases in V̂. Respiration rate and amplitude did not differ significantly between heart rate slowing and speeding trials, and covariance analysis indicated that respiratory changes did not account for the heart rate or V̂ effects. The weighted coherence between respiration and heart rate showed that cardiopulmonary coupling increased during heart rate slowing and decreased during heart rate speeding. Individual differences in cardiac vagal tone and cardiopulmonary coupling were unrelated to heart rate speeding and slowing performance.
The Relationship Between N2 and N400: Scalp Distribution, Stimulus Probability, and Task Relevance
Authors: Deacon Diana , Breton Françloise , Ritter Walter , Vaughan Herbert G. 
Published: February 2007

ABSTRACTThe N2 and N400 components of the event‐related brain potential were compared along several dimensions. In one task, subjects discriminated on the basis of size, and in another task, subjects discriminated on the basis of semantic category. In one set of conditions stimuli deviated infrequently along one stimulus dimension (either in size or semantic category) and in another set of conditions stimuli deviated infrequently along two stimulus dimensions (both size and semantic category). When subjects discriminated on the basis of size, infrequent deviation in the size of the stimuli was associated with a negativity that peaked around 320 ms (N2). When subjects discriminated on the basis of semantic category, infrequent deviation in the semantic category of the stimuli was associated with a negativity that peaked around 400 ms (N400). N2 and N400 were found to be generally alike in scalp distribution, hemispheric asymmetry, and sensitivity to stimulus probability. N2 was not elicited when size changes were task irrelevant and N400 was not elicited when changes in semantic category were task irrelevant.
Prediction of Tonic Parasympathetic Cardiac Control Using Respiratory Sinus Arrhythmia: The Need for Respiratory Control
Authors: Grossman Paul , Karemaker John , Wieling Wouter 
Published: February 2007

ABSTRACTRespiratory sinus arrhythmia (RSA) has received much attention in recent years due to the large body of evidence indicating that variations in this phenomenon represent alterations in parasympathetic cardiac control. Although it appears that respiratory sinus arrhythmia is mediated by vagal mechanisms, the extent to which the well‐known respiratory influences (i.e., rate and tidal volume) on respiratory sinus arrhythmia (in altering its magnitude) may moderate the relationship between RSA and cardiac vagal tone has never been systematically studied.We addressed this issue by examining intraindividual relationships among RSA magnitude, respiration (rate and tidal volume), and heart period among six healthy male adults after intravenous administration of 10 mg propranolol, a beta‐adrenergic blocker. Subjects were exposed to various behavioral tasks which altered all physiological variables measured. Variations in heart period after beta blockade were assumed to be predominantly vagally mediated. Within‐subject regression analyses consistently showed that respiratory parameters influenced RSA magnitude, but not tonic variations in beta‐blocked heart period, suggesting that respiratory‐mediated RSA alterations are not associated with changes in cardiac vagal tone. Only when respiratory variables were statistically controlled was there evidence of a reasonable correspondence between beta‐blocked heart period and RSA amplitude, providing support for the idea that respiratory parameters need to be controlled when using RSA amplitude as an index of cardiac vagal tone. Repeated‐measures analyses of variance of mean levels of heart period and respiratory sinus arrhythmia across subjects supplemented and supported the intraindividual results. These findings point to the importance of controlling for respiratory parameters when using respiratory sinus arrhythmia as a cardiac vagal index.
PRES: The Controlled Noninvasiv Stimulation of the Carotid Baroreceptors in Humans
Authors: Rau Harald , Elbert Thomas , Geiger Bertram , Lutzenberger Werner 
Published: February 2007

ABSTRACTTo study physiological and psychological effects of baroreceptor activity, the cervical neck cuff technique has been frequently used to stimulate the carotid baroreceptors mechanically. Using this technique, no satisfying control conditions to date have been available.Because the carotid stretch receptors are sensitive not only to the pressure level, but also to the rate of change, it is possible to manipulate the receptor firing through changes in carotid pulse amplitude. The device described here relies on the application of short changes in cuff pressure tied to different phases withing the cardiac cycle (phase related external suction (PRES)). A brief external suction during systole has potent stimulatory effects on baroreceptors whereas the application of the very same pressure pulse during diastole inhibits the firing burst associated with the pulse wave. To allow an ongoing period of stimulation, a sequence of alternating negative/positive pressure pulses is applied. In the stimulation condition, the R‐wave of the electrocardiogram triggers a negative pulse which is followed by a positive one during diastole. In the control condition this relationship is reversed.Two experiments are reported confirming different baroreceptor effects of the two conditions. PRES allows for blind or double‐blind experiments to investigate effects of baroreceptor activity on physiology and behavior.
Respiratory Sinus Arrhythmia and Cardiovascular Responses to Stress
Authors: Lane James D. , Adcock R. Alison , Burnett Rachel E. 
Published: February 2007

ABSTRACTThe parasympathetic nervous system provides mechanisms that could attenuate sympathetically mediated heart rate stress responses and might have even more general antagonistic actions on stress reactivity. Individuals characterized by higher levels of parasympathetic tone might, through such mechanisms, be less reactive when stimuli elicit sympathetically mediated responses. Respiratory sinus arrhythmia (RSA) is considered to be a noninvasive index of cardiac parasympathetic (vagal) tone. The present study investigated whether individual differences in RSA level at rest could predict variations among individuals in the magnitude of cardiovascular responses to psychological stress. None of the measures of resting respiratory sinus arrhythmia, derived from spectral analysis of beat‐to‐beat changes in resting heart rate, predicted the observed variations in cardiovascular task reactivity. However, scores reflecting respiratory sinus arrhythmia as the percentage of total heart rate variability (RSAnorm) were negatively correlated with blood pressure levels, both at rest and during the task. Furthermore, subjects with higher scores for RSAnorm demonstrated a faster adaptation of heart rate responses during stress, which suggests the development of parasympathetic antagonism to ongoing sympathetic arousal. Although a simple relationship between respiratory sinus arrhythmia and reactivity was not observed, these results encourage further investigation of RSA measures as psychophysiological indices of individual differences in parasympathetic (vagal) cardiac tone, or perhaps of general parasympathetic/sympathetic balance, which could modulate the expression of potentially pathogenic stress responses.
Family History of Hypertension and Cardiovascular Changes During High and Low Affect Provocation
Authors: Lamensdorf Angela M. , Linden Wolfgang 
Published: February 2007

ABSTRACTThe present study investigated whether subjects with a positive family history of hypertension would display differential responses in blood pressure and heart rate across different laboratory tasks. We also wanted to know whether subjects would display stable within‐subject responses across different laboratory tasks. Twenty‐three family history positive subjects and 23 with a negative family history participated in three tasks: 1) mental arithmetic, 2) a conversation about the weather (low affect task), and 3) a conversation about a recent upsetting, interpersonal event (high affect task). Positive family history was associated with elevated diastolic resting blood pressure and greater diastolic responsivity overall. For both groups, arithmetic was associated with the greatest heart rate changes, whereas the distressing conversation was accompanied by the greatest diastolic blood pressure response. Stability of cardiovascular activation across different tasks was present only for heart rate; it was weak for diastolic blood pressure, and completely absent for systolic blood pressure.
The relationship between trait hostility and cardiovascular reactivity: A quantitative review and analysis
Authors: SULS JERRY , WAN CHOI K. 
Published: February 2007

AbstractResults of a series of meta‐analyses indicated that high and low scorers on most trait hostility measures do not consistently differ in blood pressure or heart rate reactivity to traditional laboratory stressors. The few significant effects were modest in size, and instances of hyporeactivity were found. When stressors were classified as provocative versus nonprovocative, in accord with Trait x Situation approaches, however, Potential for Hostility‐Interpersonal Style was predictive of exaggerated systolic and diastolic blood pressure responses and the Cook–Medley Hostility Inventory was predictive of diastolic blood pressure responses to provocative stressors. Hence, the next generation of studies of the hostility–reactivity hypothesis should emphasize interpersonal stressors. Alternative mechanisms for the disease consequences of hostility should also be examined, however, because the available evidence indicates that the hyperreactivity hypothesis is unlikely to furnish a complete explanation for the association between hostility and heart disease.
Conscious and nonconscious processes: An ERP index of an anticipatory response in a conditioning paradigm using visually masked stimuli
Authors: WONG PHILIP S. , SHEVRIN HOWARD , WILLIAMS WILLIAM J. 
Published: February 2007

AbstractThis study investigates the nonconscious elicitation of a previously conditioned response by using a differential conditioning paradigm with visually masked affectively valent facial schematics. Electrodermal (skin conductance response [SCR]) and brain (event‐related potential [ERP]) activity were main dependent measures. Following a preconditioning phase in which subjects viewed energy masked pleasant and unpleasant facial schematics, conditioning with an aversive shock was established to unmasked presentations of an unpleasant face in a partial factorial design. A postconditioning phase of masked presentations, when compared with the preconditioning phase, revealed how the conditional effect within awareness might affect the same stimuli when presented outside awareness. An adaptive staircase technique was used to establish individual threshold levels, which represented a methodological advance over procedures typically used in visual masking research. The results revealed that responses to the CS+ (unpleasant face) changed significantly in predicted directions from preconditioning to postconditioning phase when compared with responses to the CS− (pleasant face). The SCR results systematically replicated recent Ohman, Dimberg, and Esteves (1988) findings, with the pattern of responses resembling a resistance to extinction effect. A new finding emerged for the brain responses. For the CS+, distinct slow wave activity occurred just before the point at which the shock had been delivered in the conditioning phase; no such activity was found for the CS−. This slow wave activity is similar to what has been described by others as an expectancy wave. The results indicate that an anticipatory process, as indexed by different physiological systems, can be elicited entirely outside awareness. Implications are discussed in regard to the nature of conscious and nonconscious processes.
An ERP study on visual spatial priming with peripheral onsets
Authors: EIMER MARTIN 
Published: February 2007

AbstractVisual event‐related potentials were measured for peripheral target stimuli that were preceded by a peripheral square. Targets appeared either at the same location as the square or in the opposite visual hemifield. In Experiment 1, 75% of the trials were same‐location trials, and in Experiment 2, same‐ and opposite‐location trials were equiprobable. The subject's overt response was dependent either on the identity or on the location of the target. In both experiments, opposite‐location targets elicited an enhanced PI at posterior electrodes ipsilateral to the position of the letter. This enhancement may be due to a sensory inhibition of same‐location targets. Same‐location targets elicited an enhanced negativity between 130 and 300 ms, with a first peak located parietally and a second peak broadly distributed over midline electrodes. This effect was larger in Experiment 1 than in Experiment 2 and is interpreted as enhanced processing of same‐location targets due to an attentional orienting process elicited by the peripheral square.
Signal attenuation as a function of integrator time constant and signal duration
Authors: BLUMENTHAL TERRY D. 
Published: February 2007

AbstractIn some laboratories, cyeblink electromyogram is rectified and smoothed before the analog signal is digitized. The relationship among the integrator time constant, the duration of the response, and the attenuation of the data was investigated by passing a number of signals at durations of 5, 10, 20, 50, and 100 ms into a contour‐following integrator (Coulbourn model S76–01), which first rectifies and then smooths (integrates) the signal. Integrator time constants of 10, 42, 70, 144, and 300 ms were used. The output of the integrator was sampled (1,000 Hz) and stored on a Macintosh SE computer. The integrator attenuated the signal, and the amount of attenuation increased as the duration of the signal decreased and as the time constant of the integrator increased. For brief inputs, the integrator does not charge fully, so only the early portion of the charge limb is present, and this early portion is the steepest part of the charge limb. Therefore, the longer the time constant, the less likely that small or brief responses will be detected.
Feasibility of intracranial near‐infrared optical scanning
Authors: GRATTON GABRIELE , MAIER JOHN S. , FABIANI MONICA , MANTULIN WILLIAM W. , GRATTON ENRICO 
Published: February 2007

AbstractLight injected at a point on a surface of a scattering medium is emitted at the surface after traveling a quasisemicircular path deep into the medium. This phenomenon can be exploited to detect objects immersed in the medium from time‐resolved measurements of light intensity at the surface. Our experiments on model systems demonstrate that absorbing objects, surrounded by bone and other scattering material, can be detected. The technique yields surface images of absorbing objects submerged in a scattering medium. Images of the same phantoms inside the cavity of a skull can be obtained by the same technique.
Modulation of event‐related brain potentials by word repetition: Effects of local context
Authors: RUGG MICHAEL D. , DOYLE MICHAEL C. , HOLDSTOCK JULIET S. 
Published: February 2007

AbstractIn four experiments, event‐related brain potentials (ERPs) were evoked by visually presented word pairs in a task requiring responses to occasional target pairs. In Experiments 1 and 2, some pairs comprised items that had been presented previously. These repeated pairs consisted of words that had been paired together when first presented (same context condition) or words that had first been presented on consecutive trials (different context condition). ERP repetition effects were equivalent in the two conditions. In Experiment 3, same‐context repeats were contrasted with a condition in which a repeated word was paired with a new word. Only the same‐context pairs evoked a repetition effect. Experiment 4 showed that repetition effects to different‐ and same‐context repeats remained equivalent when first presentations of the members of different‐context pairs were separated by six intervening trials. We conclude that the ERP repetition effect shows little sensitivity to local context.
Brain event‐related potential correlates of overfocused attention in obsessive‐compulsive disorder
Authors: TOWEY JAMES P. , TENKE CRAIG E. , BRUDER GERARD E. , LEITE PAUL , FRIEDMAN DAVID , LIEBOWITZ MICHAEL , HOLLANDER ERIC 
Published: February 2007

AbstractA hypothesis of overfocused attention in obsessive‐compulsive disorder was investigated by measuring auditory event‐related potentials (ERPs) during a selective attention task. Unmedicated patients (n= 18) with this disorder showed significantly larger attention‐related processing negativity (PN), with earlier onset and longer duration, than did normal controls (n= 15). In the N200 region (160–250 ms), PN was larger in patients with fewer nonspecific neurological soft signs. This task, however, did not yield any group differences in mismatch negativity (N2a) or classical N200 (N2b). P300 amplitudes for attended targets were smaller for patient than normal groups, but the reverse was true for P300 and positive slow wave amplitudes for unattended nontargets. Collectively, these ERP abnormalities suggest a misallocation of cognitive resources. Because of the importance of the frontal lobe in the control of selective attention, PN enhancement in patients with obsessive‐compulsive disorder may reflect hyperactivation of this region. This conceptualization is consistent with recent functional neuroimaging findings.