bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influences of Potential for Hostility, Type A Behavior, and Parental History of Hypertension on Adolescents’ Cardiovascular Responses During Stress
Authors: McCann Barbara S. , Matthews Karen A. 
Published: February 2007

ABSTRACTWe investigated the influences of Type A behavior, potential for hostility, and parental history of diagnosed hypertension on adolescents’ cardiovascular responses to three behavioral stressors. The participants were 72 male and 99 female adolescents enrolled in grades 6 to 12. Results showed that adolescents with a hypertensive parent had larger diastolic blood pressure responses during all three stressors than did adolescents without hypertensive parents; this effect was particularly pronounced among the Type As. Adolescents rated as high on potential for hostility had elevated systolic and diastolic blood pressure responses, particularly during isometric exercise. Results regarding parental history of hypertension and Type A replicate previous studies in adolescents. Results regarding potential for hostility showed for the first time that early signs of hostility are related to psychophysiological responses thought to be pathophysiological mechanisms in the etiology of cardiovascular diseases.
Effects of Foveal Task Load on Visual‐Spatial Attention: Event‐Related Brain Potentials and Performance
Authors: Kramer Arthur F. , Sirevaag Erik J. , Hughes Paul R. 
Published: February 2007

ABSTRACTThe effects of foveal task difficulty on the processing of events in the visual periphery were investigated through an analysis of event‐related brain potentials and performance measures. Subjects performed a foveally presented continuous monitoring task both separately and together with an arrow discrimination task that was presented at three different retinal eccentricities. The subjects detected occasional failures in the monitoring task while also responding to designated targets in the left and right visual fields. The analysis of the event‐related brain potentials elicited by discrete events in the arrow discrimination task indicated that the amplitude of the N190 and P300 components decreased with both the introduction of the foveal task and an increase in its difficulty. The N160 component was sensitive to the distribution of attention within a task but was uninfluenced by dual task demands. These findings suggest that the N160 reflects the distribution of attention to different spatial locations within a task while the N190 may index the distribution of general purpose perceptual resources. P300 appears to index the allocation of perceptual/central processing resources. The implications of the results for models of resource allocation and attentional gradients are discussed.
Electrodermal Lability and Dichotic Listening
Authors: O'Gorman J. G. , Lloyd Jacqueline E. M. 
Published: February 2007

ABSTRACTSubjects identified as electrodermal labiles and stabiles on the basis of frequency of nonspecific skin conductance responses during a resting period were presented with a series of auditory stimuli followed by dichotic presentation of different sets of words to each ear with the requirement to report as many words as possible irrespective of ear. Labiles performed better than stabiles on the dichotic listening task and were found to habituate skin conductance response more slowly to both tones and dichotic stimuli, and to show higher skin conductance level during both stimulus series and higher heart rate level during the dichotic series. There were no significant differences between the groups on a measure of EEG alpha activity during either series. The data were consistent with an arousal rather than an attentional interpretation of the labile‐stabile difference.
ERP Components in Picture Matching in Children and Adults
Authors: Friedman David , Sutton Samuel , Putnam Lois , Brown Charles , Erlenmeyer‐Kimling L. 
Published: February 2007

ABSTRACTEvent‐related potentials (ERPs) were recorded from 22 young children (aged 6–8) and 25 adults (aged 20–38) in a modification, using pictorial stimuli, of Posner's (1978) letter‐matching paradigm. Subjects were required to decide whether two line drawings, presented sequentially, were the same or different on the basis of whether they were physically identical, shared the same name, or were in the same category. Subjects always made a choice “same’ or “different” delayed response whose meaning depended on the operative instruction condition in that block of trials.The ERPs elicited by S1 and S2 with this paradigm from both age groups were of complex morphology, with P300 to both S1 and S2, the E‐wave preceding S2, and N400 possibly homologous for children and adults. P300, N400, and E‐wave probably had similar functional roles for children and adults as attested by the lack of significant interactions between age groups and the cognitive variables manipulated in the experiment. However, group differences in scalp distribution for one of these components suggest that although they may be generically similar across groups, they are probably not identical with respect to brain generators. In addition, there were group differences in timing of P300 in the two age groups. Overall, the ERP findings suggest that the cognitive processing of children and adults in the same task is different, although the behavioral data lend only partial support for these conclusions.
Early and Late Selection in Young and Old Adults: An Event‐Related Potential Study
Authors: de Jong Huib Looren , Kok Albert , van Rooy John C.G.M. 
Published: February 2007

ABSTRACTThe present experiment investigated differences in processing between young and old adults in a combined visual selection‐memory search paradigm. No evidence was found for age‐related differences in early visual selective attention. The elderly achieved relatively fast reaction times in the memory search task at the cost of a high error percentage. From these findings, and from the morphology of the event‐related potential, it was concluded that old subjects perform controlled memory search more superficially than young subjects, In both old and young subjects high memory load was associated with decreased positivity in the P3 and Slow Wave area. This is interpreted in terms of Okita et al.'s(1985) concept of search negativity. N2 amplitude was found to be larger to non‐target trials for both attended and unattended inputs. The latter result is discussed in relation to theories about N2 as an indicator of automatic mismatch detection.
Difficulty and Instrumentality of Imminent Behavior as Determinants of Cardiovascular Response and Self‐Reported Energy
Authors: Wright Rex A. , Gregorich Steve 
Published: February 2007

ABSTRACTCollege‐aged male subjects were presented with an easy or moderately difficult memorization task and were told that they could earn either a very low or a very high chance of obtaining a modest prize if they did well. Cardiovascular (heart rate, systolic blood pressure, diastolic blood pressure) and subjective measures were taken during an interval immediately preceding the task performance period. Results indicated greater systolic blood pressure and self‐perceived energy in the moderately difficult condition than in the easy condition only when the probability of attaining the prize (if subjects did well) was high. When the probability of goal attainment (given success) was low, systolic responses and self‐reported energy levels were minimal in both task conditions. Predictions regarding the impact of energy levels upon goal attractiveness ratings were not supported, possibly for methodological reasons.
Variations in Period‐Analysed EEG Asymmetry in REM and NREM Sleep
Authors: Armitage Roseanne , Hoffmann Robert , Loewy Derek , Moffitt Alan 
Published: February 2007

ABSTRACTMonopolar EEG was recorded from lateral frontal and parietal sites with linked ear reference during sleep in 24 adults. Electrode placement followed the 10–20 International system. EEG was quantified using digital period analyses. The absolute difference in interhemispheric EEG parameters was compared for Stage 2, REM, and a slow wave sleep measure. The absolute difference measures reflect the degree of symmetry or asymmetry, regardless of the hemisphere of origin. Theta and delta activity in slow wave sleep was more asymmetrical than in either Stage 2 or REM. REM sleep was associated with the smallest asymmetries. These results do not support a right hemisphere REM, left hemisphere NREM relationship. Rather they suggest that REM sleep is associated with relative hemispheric symmetry whereas asymmetries are most prominent in slow wave sleep. Stage 2 sleep was significantly less asymmetrical than slow wave on a number of theta and delta measures. The significant differences between slow wave and Stage 2 sleep may denote functional differences within NREM sleep stages.
Effects of Motivation and Verbal Response Type on Psychophysiological Detection of Information
Authors: Elaad Eitan , Ben‐Shakhar Gershon 
Published: February 2007

ABSTRACTTwo independent experiments were designed to investigate the effects of motivation to deceive and the type of verbal response on psychophysiological detection using the Guilty Knowledge Technique. The first was a field experiment in which 72 subjects were randomly assigned to 8 experimental conditions. These conditions were created by a 2 × 4 factorial design (two motivational states crossed with four verbal response modes‐affirming, denying, repeating, or no verbal response to questions about personal information). The second experiment was a laboratory experiment in which 160 students were assigned to the same 8 conditions. Results of both experiments indicated that highly motivated subjects were detected better than less motivated subjects. The act of lying was associated with enhanced differential responsivity, but no effects were obtained for verbal response versus no response or for variable versus standard verbal response. Differential responsivity tended to decline when questions were repeated. The first experiment revealed a clear advantage of electrodermal measures over respiration and cardiovascular measures. The results were discussed in relation to previous findings, a new theoretical formulation, and practical implications.
Prepulse Rise Time and Startle Reflex Modification: Different Effects for Discrete and Continuous Prepulses
Authors: Blumenthal Terry D. , Levey Bard J. 
Published: February 2007

ABSTRACTThe rise time of an auditory prepulse was varied to determine whether the onset transient of the prepulse is of primary importance in the modification of the acoustic startle reflex. In Experiment 1, 20‐ms long discrete prepulses were presented at a lead time of 150 ms, and prepulse rise time was varied from 0.1 to 20 ms. Although all prepulses resulted in decreased response amplitude (inhibition of startle), varying rise time from 0.1 to 20 ms had no effect on reflex modification. These results suggest that the startle response is not sensitive to prepulse rise time changes in the range used here. In Experiment 2, continuous prepulses (in which lead time equals duration) were presented. Several of these prepulses had a lead time of 150 ms and rise times ranging from 0.1 to 150 ms, whereas others had a rise time of 0.1 ms and lead times of 50 to 150 ms. The results showed that only the fast‐rising, 50‐ms lead time prepulse decreased response amplitude, with the other prepulses having no effect on amplitude, relative to control responding. Rise time changes generally had no effect on responding, but responses were larger at longer lead times than at shorter lead times. Response probability was inhibited by fast‐rising prepulses at lead times of 50 to 130 ms. Together with the results of Experiment 1, these findings suggest that startle reflex inhibition is determined by the onset of a prepulse, and that this inhibition is not sensitive to small changes in prepulse rise time. Also, startle reflex facilitation is determined by the steady‐state portion of the prepulse, and this effect is sensitive to prepulse duration. The inhibitory and facilitatory effects combine to determine the amount and direction of reflex modification, and these effects have different time courses, suggesting different mechanisms. It is suggested that reflex modification is due to the activation of a transient system for startle inhibition and a sustained system for startle facilitation.
Aerobic Fitness, Physical Activity, and Psychophysiological Reactions to Mental Tasks
Authors: Steptoe Andrew , Moses Jennifer , Mathews Andrew , Edwards Sara 
Published: February 2007

ABSTRACTThe association between aerobic fitness, exercise, and psychophysiological reactivity was assessed in cross‐sectional and prospective analyses. Seventy‐five healthy but sedentary adults carried out a sub‐maximal exercise test and easy and difficult problem solving tasks. Blood pressure, heart rate, skin conductance level, respiration rate, tidal volume, and oxygen consumption were monitored and additional heart rate was also computed. Differences between relatively fit and unfit individuals were found in respiration rate during tasks and in skin conductance level during post‐task recovery periods, with a tendency toward diminished heart rate reactivity in fitter people. Subjects were subsequently allocated to four conditions: high intensity aerobic training, moderate intensity aerobic training, an undemanding strength and flexibility program (designed as an attention‐placebo condition), and waiting list control. Training programs were conducted over a 10‐week period, and were followed by a second laboratory session. Appropriate changes in aerobic performance over the training period were observed in the 12‐min run/walk test. There were no important modifications in psychophysiological stress reactions associated with the different experimental conditions. These results are discussed in relation to the literature concerning the effects of fitness and physical activity on physiological response patterns.
Do Instructions Modify Effects of Beta‐adrenoceptor Blockade on Anxiety?
Authors: Fredrikson Mats , Klein. Kerstin , ÖHman Arne 
Published: February 2007

ABSTRACTTo study the interaction between physiological and cognitive factors in anxiety, 44 subjects with public speaking anxiety were allocated to four different groups. Two groups received either beta‐adrenoceptor blockade (100 mg of atenolol) or placebo orthogonally crossed with an instruction that heart rate would decrease or an instruction that did not mention cardiovascular effects. During the delivery of a speech, measures of heart rate, systolic and diastolic blood pressures, and self‐reported anxiety were obtained. All variables increased during an anticipation period before speech, and heart rate, systolic blood pressure, and self‐reported anxiety increased further during speech. Regardless of instructions, atenolol decreased heart rate and systolic blood pressure during both anticipation and speech, whereas no differences were found in self‐reported anxiety. This lack of a relationship was seen in spite of the correctly perceived heart rate reduction in the atenolol‐treated group receiving an instruction that heart rate would decrease. Cardiac aware subjects, according to the Autonomic Perception Questionnaire, showed higher levels of heart rate and self‐reported anxiety at rest than did cardiac unaware subjects. During speech, even though heart rate was similar in atenolol treated groups, self‐reported anxiety was higher in cardiac aware than in cardiac unaware subjects. The lack of a relationship between heart rate and self‐reported anxiety is discussed in terms of primary and secondary emotions. It is suggested that the perception of external rather than internal cues determines situationally elicited anxiety.
Asymmetrical Brain Electrical Activity Discriminates Between Psychometrically‐Matched Verbal and Spatial Cognitive Tasks
Authors: Davidson Richard J. , Chapman Jean P. , Chapman Loren J. , Henriques Jeffrey B. 
Published: February 2007

ABSTRACTThis study compared the asymmetry of different features of brain electrical activity during the performance of a verbal task (word finding) and a spatial task (dot localization) that had been carefully matched on psychometric properties and accompanying motor activity. Nineteen right‐handed subjects were tested. EEG was recorded from F3, F4, C3, C4, P3, and P4, referred to both Cz and computer‐derived averaged‐ears references, and Fourier transformed. Power in the delta, theta, alpha, and beta bands was computed. There were significant Task X Hemisphere effects in all bands for Cz‐referenced data and for the alpha and beta bands for ears‐referenced data. The effects were always either greater power suppression in the hemisphere putatively most engaged in task processing or greater power in the opposite hemisphere. Correlations between EEG and task performance indicated that Cz‐referenced parietal alpha asymmetry accounted for the most variance in verbal task performance. Power within individual hemispheres or across hemispheres was unrelated to task performance. The findings indicate robust differences in asymmetrical brain physiology that are produced by well‐matched verbal and spatial cognitive tasks.
Photoresistive Measurement of the Pavlovian Conditioned Eyelid Response in Human Subjects
Authors: Durkin Martin , Prescott Louisa , Jonet C. Jean , Frank Elaine , Niggel Michael , Powell Donald A. 
Published: February 2007

ABSTRACTAn inexpensive technique is described for measuring eyelid closure during classical (Pavlovian) conditioning experiments. This technique employs a Coulbourn Instruments Co. densitometric device that focuses a beam of infrared light on the cornea. Reflection of the light is interrupted by the eyelids when they are closed, which is sensed by an infrared detector. The latter causes a voltage change to occur, which can then be measured in a variety of ways. Details of both the hardware required and software developed for this purpose are described.
Disruption and Recovery of the Orienting Response Following Shock or Context Change in Preweanling Rats
Authors: Saiers Jane A. , Richardson Rick , Campbell Byron A. 
Published: February 2007

ABSTRACTPrevious research has shown that placement of preweanling rats in an unfamiliar environment inhibits both heart rate and behavioral orienting responses to an auditory stimulus, and that the orienting response gradually reappears during the following 15 min. Four experiments designed to evaluate two potential explanations of this effect were conducted. If the arousal induced by an unfamiliar environment disrupts sensory information processing, so should the arousal induced by mild electric shock. In two experiments, the orienting response was inhibited in proportion to number of shocks received and rate of recovery was comparable to that observed in the unfamiliar environment. New environments also contain many unfamiliar stimuli which may overload the rats’ limited information processing capacity. In two experiments a change in environmental stimulation was shown to inhibit the orienting response. Recovery of the orienting response followed the same time course as that seen following shock or placement in an unfamiliar environment. Although the results of this study clearly demonstrate environmental inhibition of the orienting response, they provide little support for either the “arousal” or the “information overload” hypotheses of orienting response inhibition. The implications of these data for current theoretical conceptualizations of the orienting response are discussed.
Existing and Training Induced Differences in Aerobic Fitness: Their Relationship to Physiological Response Patterns During Different Types of Stress
Authors: DE Geus Eco J.C. , van Doornen Lorenz J.P. , de Visser Dianne C. , Orlebeke Jacob F. 
Published: February 2007

ABSTRACTAerobic fitness has been associated with various desirable psychological and physiological characteristies. Recently, attenuation of physiological reactivity during stressful situations was added to this list, although comparison of the stress responses of sportsmen and sedentary subjects has yielded equivocal results. The present study examined cardiovascular patterns rather than single variables, and tried to clarify these matters. Tasks were used that were known to increase blood pressure through different combinations of changes in cardiac output and vascular resistance. Autonomic nervous system dynamics underlying these response patterns were studied using preejection period as an index of β‐adrenergic activity, and respiratory sinus arrhythmia as an index of vagal activity. Pre‐existing differences in aerobic fitness in a sample of sedentary subjects were related to their responses during the stressful tasks and the recovery periods afterwards. This approach prevented confounding of the relationship between fitness and stress‐reactivity with the psychological effects of regular exercise. Furthermore, it excluded the bias in psychological makeup that is introduced when subjects spontaneously engaged in sports are compared to non‐exercising persons. To rule out a third (hereditary?) factor underlying both stress‐reactivity and fitness, physiological responses before and after a seven‐week training program were compared to those of subjects in a waiting list control group. Substantial individual differences in aerobic fitness were found in spite of the fact that all subjects reported low levels of habitual activity. During two active coping tasks, diastolic blood pressure reactivity and vagal withdrawal were negatively related to these pre‐existing differences in fitness. No such relation was seen during a cold pressor test or during recovery from the tasks. Neither β‐adrenergic cardiac reactivity nor heart rate responses were related to fitness, but the absolute heart rate during the tasks was lower in the more fit subjects. Seven weeks of training were not effective in changing either reactivity or recovery of any of the variables. The discrepancy between cross‐sectional and longitudinal results in the present study suggests that training of longer duration is necessary to induce the psychological or physiological changes underlying reduced reactivity. The latter may include changes in cardiac vagal/sympathetic balance or in adrenoceptor sensitivity. Alternatively, both psychological and physiological determinants of stress‐reactivity may be related to aerobic fitness at a dispositional level.
Electrodermal Responsivity in Young Hypotensive and Hypertensive Men
Authors: Fredrikson Mats , Edman Gunnar , Levander Sten E. , Schalling Daisy , Svensson Jan , Tuomisto Martti 
Published: February 2007

ABSTRACTElectrodermal responses were recorded during the presentation of 16 moderately intense (1000 Hz, 90dB) tones in three groups of young men: borderline hypertensives (138/79 mmHg), normotensives (112/65 mmHg), and hypotensives (104/63 mmHg). Electrodermal response habituation was measured as a decline in response over trials, number of trials to a response criterion of three successive nonresponses, and number of inversions of response amplitude (larger responses following smaller responses) in the stimulus sequence. Habituation was fastest in hypotensives. Nonspecific electrodermal responses at rest and during tone presentations were most frequent in borderline hypertensives, least frequent in the hypotensive group, with the normotensive group falling in between. There were no significant differences in electrodermal level. The rapid habituation rate in hypotensives is discussed in terms of cursory information processing associated with impulsive behaviour. The higher nonspecific electrodermal activity in borderline hypertensives is interpreted to indicate increased sympathetic nervous system activity.