bluuebunny/crossref_metadata_2025_split huggingface dataset:
ERP and behavioral changes during the wake/sleep transition
Authors: HARSH JOHN , VOSS URSULA , HULL JOHN , SCHREPFER STEFFI , BADIA PIETRO 
Published: February 2007

AbstractEvent‐related potentials (ERPs) following infrequent and frequent stimuli were studied as subjects moved from wakefulness to sleep. Subjects were instructed to respond to the infrequent “target” stimuli (attend condition) or to ignore the stimuli (ignore condition). Parietal P300, prominent following target ERPs in wakefulness under the attend condition, disappeared in association with reduced behavioral responsiveness and emergence of a central negativity (N350). The N350 and preceding and following positivities (P220 and P450) became the dominant feature of both target and nontarget ERPs under both attend and ignore conditions. The P220‐N350‐P450 complex was larger and peak latencies were shorter under the attend condition. Peak amplitudes tended to be larger following targets, especially under the attend condition. The findings suggest that, although the processes under‐lying P300 are less likely to be engaged, processing of stimulus deviance and task relevance continues in sleepiness and sleep, and is reflected by variance in N350 and related activity.
Influence of caffeine on selective attention in well‐rested and fatigued subjects
Authors: LORIST MONICQUE M. , SNEL JAN , KOK ALBERT , MULDER GIJSBERTUS 
Published: February 2007

AbstractEffects of caffeine were studied in a visual focused selective search task in well‐rested and fatigued subjects. A dose of 200 + 50 mg caffeine or placebo, dissolved in decaffeinated coffee, was administered in a double‐blind and deceptive fashion. The task was to detect a target letter on one diagonal of a visual display designated as relevant and ignore stimuli presented on the irrelevant diagonal. Behavioral measures were supplemented by event‐related potential (ERP) measures. Subjects reacted faster in the caffeine condition. Caffeine enhanced the N1 and the N2b components. Selection of relevant information apparently was more adequate in this condition. Search negativity was not affected by caffeine. Caffeine effects on the P3 elicited by target letters were more pronounced in the fatigued than in the well‐rested subjects, indicating that the effects of caffeine are dependent on the state of the subject. The results suggest that caffeine has specific rather than general effects on information processing.
Changes in brain activity patterns in aging: The novelty oddball
Authors: FABIANI MONICA , FRIEDMAN DAVID 
Published: February 2007

AbstractA decrease in the frontal lobes' efficiency is supposed to play a role in age‐related changes in cognitive function. If frontal lobes are involved in the maintenance of working memory, the elderly may require increased frontal activity because of more rapid memory decay. This is consistent with the fact that the P3 component of the eventrelated potential (ERP) has a more frontal orientation with increasing age. However, frontally distributed P3s are also observed in young people when novel stimuli are unexpectedly presented in an oddball paradigm. Young and old subjects were run in an auditory novelty oddball in which ERPs were recorded from 30 scalp sites. The young adults' P3s showed either a posterior (targets) or more frontally oriented (novels) scalp focus. The elderly were less accurate in their memory for the novel stimuli, and their P3s showed anterior and posterior foci to both targets and novels. The young adults' target P3s changed over time from a frontal to a posterior focus, whereas the old adults' did not. These results are consistent with decreased ability of the elderly to maintain the templates needed for stimulus categorization.
Cardiac function and behavioral reactivity during infancy
Authors: SNIDMAN NANCY , KAGAN JEROME , RIORDAN LINDA , SHANNON DANIEL C. 
Published: February 2007

AbstractLongitudinal cardiac data from the end of the fetal period to 21 months of age were examined for change and stability over age and relations to the temperamental characteristics of high and low reactivity at 4 months of age and fear to the unfamiliar in the second year. Heart period and power in the cardiac spectra changed dramatically over the first 2 years, and individual differences were not preserved until 9‐14 months of age. Sleep heart period at 2 weeks of age and low frequency power at 2 months of age were better predictors of the temperamental categories than later measures of the same variables, suggesting that cardiac function early in life may be an especially sensitive index of temperamental qualities.
P300 topography in Alzheimer's disease
Authors: HOLT LORI E. , RAINE ADRIAN , PA GRACE , SCHNEIDER LON S. , HENDERSON VICTOR W. , POLLOCK VICKI E. 
Published: February 2007

AbstractThis study assessed whether P300 scalp topography distinguishes subjects with Alzheimer's disease (AD) from controls. Specifically, it was predicted that the AD group would show maximum P300 amplitude over frontal areas and t he largest P300 reduction over parietal and left hemisphere areas. These hypotheses were tested using a standard auditory oddball paradigm to compare 26 AD subjects and 26 controls matched on age, sex, handedness, and education. P300 was measured at frontal, central, parietal, and occipital sites over left and right hemispheres and along the midline. Results revealed that the distribution of P300 was different for the two groups such that the controls manifested a maximum over parietal areas, whereas the AD subjects showed a maximum at frontal sites with the largest reductions in P300 over parietal areas. No hemispheric differences in P300 were found. These results are consistent with the hypothesis that P300 represents the activity of multiple neural generators that are differentially disrupted by the disease process.
Attentional modulation of startle in psychosis‐prone college students
Authors: SCHELL ANNE M. , DAWSON MICHAEL E. , HAZLETT ERIN A. , FILION DIANE L. 
Published: February 2007

AbstractAttentional modulation of startle eyeblink was studied in college students putatively at risk for psychosis and in normal controls. At‐risk subjects had extreme scores on scales for either anhedonia or perceptual aberration‐magical thinking (per‐mags). Subjects were presented with to‐be‐attended and to‐be‐ignored tones; white noise startle probes were presented at lead intervals of 60, 120, 240, or 2,000 ms following the onset of attended and ignored tones and during intertone intervals. Controls showed greater inhibition of startle blink at 120 ms and greater facilitation at 2,000 ms during to‐be‐attended than to‐be‐ignored tone, demonstrating attentional modulation of prepulse inhibition and facilitation. Both at‐risk groups showed normal overall levels of early inhibition and late facilitation. However, per‐mags failed to show attentional modulation of either inhibition at 120 ms or facilitation at 2,000 ms; anhedonics showed no modulation of inhibition and modulation of facilitation was delayed in development. The results for the per‐mags are strikingly similar to those observed in schizophrenic patients and suggest that these deficits index a trait‐linked vulnerability to disorders in the schizophrenic spectrum.
Hebb's concept of cell assemblies an the psychophysiology of word processing
Authors: PULVERMÜLLER FRIEDEMANN 
Published: February 2007

AbstractHebb's brain‐theoretical approach suggests that tightly connected networks of neurons, Hebbian cell assemblies, are the building blocks of cognitive functions. These assemblies are not necessarily restricted to a small cortical locus but may be dispersed over distant cortical areas. Assemblies with different topographies can be postulated for different kinds of words, such as meaningful content versus grammatical function words or words eliciting motor versus visual associations. Evidence from evoked potentials and gamma‐band electrocortical responses elicited by lexical material supports a cell assembly model of language and other higher cognitive functions.
On the validity of estimating EEG correlation dimension from a spatial embedding
Authors: PRITCHARD WALTER S. , KRIEBLE KELLY K. , DUKE DENNIS W. 
Published: February 2007

AbstractWe demonstrate by using simulations that spatial embedding of single‐variable time series data does not reliably reconstruct state‐space dynamics. Instead, correlation dimension estimated from spatially embedded data is largely a measure of linear cross‐correlation in the data set. For actual electroencephalographic (EEG) data, we demonstrate a high negative correlation between spatial correlation dimension and the average amount of lag‐zero cross‐correlation between “nearest‐neighbor” embedding channels (the greater the cross‐correlation, the lower the dimension). We also show that the essential results obtained from spatially embedding EEG data are also obtained when one spatially embeds across a set of highly cross‐correlated stochastic (second‐order autoregressive) processes. Although, with appropriate surrogate data, correlation dimension estimated from spatially embedded data detects nonlinearity, its use is not recommended because correlation dimension estimated from temporally embedded data both reconstructs state‐space dynamics and, with appropriate surrogate data, detects nonlinearity as well.
Predicting sleep latency from the three‐process model of alertness regulation
Authors: ÄKERSTEDT TORBJÖRN , FOLKARD SIMON 
Published: February 2007

AbstractThis paper presents a modification of the quantitative “three‐process model of alertness regulation” to predict sleep latency in connection with irregular sleep/wake patterns. This model uses a circadian and a homeostatic component(sleep loss) that are summed to yield predicted alertness (on a scale of 1 to 20) across a specified time span. The timing of sleep from two studies of irregular sleep were used as input to the model. The predicted alertness at bedtime was regressed on empirical sleep latency from two studies. The maximum R2 (0.88) was reached for an exponential function, with the model acrophase set to 2048. The predictions were cross validated on another set of sleep latency data from an irregular sleep study and a maximum R2 of 0.65 was obtained. In both studies, the prediction from the model explained more variance that did self‐rated alertness at bedtime. Cross validation was also carried out sucessfully with published data from two studies of shift work. It was concluded that sleep latency on irregular schedules may be predicted with accuracy from knowledge of the prior sleep/wake pattern. This may have practical consequences for rest/actvity management.
Effects of interstimulus interval on scalp topographies evoked by noxious sural nerve stimulation
Authors: DOWMAN ROBERT 
Published: February 2007

AbstractThe amplitude of the late pain‐related negative‐positive peak complex, which we have labeled SP3 (134–150 ms) and SP6 (277–331 ms), respectively, increased with increasing interstimulus interval (ISI). This contrasts with the nociceptive spinal withdrawal reflex and subjective pain rating data, which implied that nociceptive somatosensory processes were unaffected by ISI at stimulus levels that were well within the pain range. A scalp topographic analysis strongly suggested that none of the brain areas responsible for SP3 or SP6 are involved exclusively in nociception. We also observed a pain‐related positive potential apporximately 161–177 ms following sural nerve stimulation that has not been reported by others. A dipole source localization analysis and the effects of ISI and stimulus intensity on this potential suggest that it is generated by the response of primary somatosensory cortex neurons to inputs arising from the innocuous peripheral afferents and that this response is inhibited by noxious inputs.
Probing picture perception: Activation and emotion
Authors: Cuthbert Bruce N. , Bradleym Margaret M. , Lang Peter J. 
Published: February 2007

AbstractWhen acoustic startle probes are presented during picture viewing, the blink reflex is augmented for unpleasant foreground stimuli and reduced during pleasant stimuli. The present experiment assessed the hypothesis that this affect‐Startle effect increases as pictures are judged to be more arousing. Eyeblinks elicited by startle probes of three different intensities were recorded while subjects viewed pictures varying in both pleasure (pleasant, neutral, and unpleasant) and arousal (low, moderate, and high). Both blink potentiation during unpleasant content and blink diminution during pleasant content were clearly strongest for picture contents high in arousal. The effect was present for all probe intensities tested.
Tracking early and late stages of information processing: Contributions of startle eyeblink reflex modification
Authors: Jennings Penny D. , Schell Anne M. , Filion Diane L. , Dawson Michael E. 
Published: February 2007

AbstractStartle eyeblink modification was examined as a measure of information processing. College students were presented with tones of 5 and 7 s duration of either high or low pitch, followed by startle‐eliciting stimuli at lead intervals of 120, 2.000, 4,500, or 6,000ms. Attention to tones was manipulated by instructing the task group to count the longer tones of either pitch. The no‐task group had no instructed task. Startle eyeblink was inhibited at the short lead interval and facilitated at the long lead intervals in both groups. The task group showed greater inhibition and facilitation during attended than during ignored tones, indicating that early and late controlled processing was occurring. In the task group, I he degree of facilitation appeared to reflect the degree of cognitive demands of the task. Startle eyeblink modification may provide a sensitive measure of the nature and timing of stapes of processing in active and passive attentional conditions.
Reproducibility of blood pressure and heart rate reactivity: A meta‐analysis
Authors: Swain Annette , Suls Jerky 
Published: February 2007

AbstractReproducibilities of blood pressure and heart rule (HR) reactivity reported in studies assessing responses to the same laboratory stressors across occasions were reviewed with meta‐analytic techniques. Changes in HR had the greatest reproducibility (r =.555), followed by systolic blood pressure (SBP) (.407) and diastolic blood pressure (DBF) (.348), Both SBP and HR response reproducibility was higher at shorter lest‐retest intervals, whereas DBP values varied unsystematically with length of test‐retest interval Older samples exhibited higher SBP and DBP reproducibility to stressors. SBP and DBP reproducibilities were better for tasks that did not make speech demands. The reliability of reactivity assessment was higher when based on three or more measurements, On the basis of able evidence, the drop in stress reproducibility, as test‐retest interval increases, places limits on the viability of BP reactivity as a strong marker or risk factor for coronary heart disease.
Event‐related brain potentials in a varied‐set memory search task: A reconsideration
Authors: KOTCHOUBEY B. I. , JORDAN J. S. , GRÖZINGER B. , WESTPHAL K. P. , KORNHUBER H. H. 
Published: February 2007

AbstractEvent‐related potentials (ERPs) were recorded in 19 healthy subjects as they completed two Sternberg (1969, American Scientist, 57, 421–457) memory tests. In separate sessions, either single digits (i.e., 0–9) or 10 abstract figures were used as stimuli. In both sessions, memory set sizes were 1 (M1), 2 (M2), or 4 (M4). The amplitude and latency of the parietal P400 and the frontocentral negativity preceding P400 varied significantly with set size, but only between M1 and M2, whereas reaction time increased dramatically from M1 to M2 and from M2 to M4. These findings challenge previous assertions that the ERPs reflect aspects of the exhaustive serial search proposed by Sternberg. A late parietal positivity (P620), which failed to vary with set size, was larger in response to figures than to digits and may represent the search for, or utilization of, semantic traces of the stimuli.
Perceptual factors affecting age‐related differences in focused attention: Performance and psychophysiological analyses
Authors: ZEEF ELLY J. , SONKE CORINE J. , KOK ALBERT , BUITEN MEREL M. , KENEMANS J. LEON 
Published: February 2007

AbstractIn this study, the impact of two perceptual factors, feature similarity and spacing, on age‐related differences in performance and psychophysiological measures were investigated within a focused attention paradigm. Young and old subjects performed an Eriksen letter identification task, in which centrally presented targets were flanked by response‐compatible or response‐incompatible letters. In feature similarity conditions, targets and flankers had a low or high amount of feature overlap. In spacing conditions, flankers were presented at four different lateral positions from the target. In the condition with high feature overlap and shortest target‐flanker distance, old subjects showed greater interference by incompatible flankers than young subjects. Feature similarity was of little influence on age‐related differences. However, spacing turned out to be of critical importance. Age‐related interference effects disappeared when the target‐flanker distance increased. This appears to be due to a decrease in response competition.
Brain activation, affect, and aerobic exercise: An examination of both state‐independent and state‐dependent relationships
Authors: PETRUZZELLO STEVEN J. , TATE ANDREW K. 
Published: February 2007

AbstractResting electroencephalograph (EEG) asymmetry is a biological marker of the propensity to respond affectively to, and a measure of change in affect associated with, acute aerobic exercise. This study examined the EEG‐affect–exercise relationship. Twenty participants performed each of three randomly assigned 30‐min conditions: (a) a nonexercise control, (b) a cycling exercise at 55% VO2max, and (c) a cycling exercise at 70% VO2max. EEG and affect were assessed pre‐ and 0, 5, 10, 20, and 30 min postcondition. No significant results were seen in the control or 55% conditions. In the 70% exercise condition, greater relative left frontal activation preexercise predicted increased positive affect and reduced state anxiety postexercise. Participants (n= 7) with extreme relative left frontal activation post‐exercise reported concomitant decreases in anxiety, whereas participants (n= 7) with extreme relative right frontal activation postexercise reported increases in anxiety. These findings (a) replicate prior work, (b) suggest a dose‐response intensity effect, and (c) support the idea that exercise is an emotion‐eliciting event. Affective responses seem to be mediated in part by differential resting levels of activation in the anterior brain regions. Ongoing anterior brain activation reflected concurrent postexercise affect.
Assessment of posture and motion by multichannel piezoresistive accelerometer recordings
Authors: FAHRENBERG JOCHEN , FOERSTER FRIEDRICH , SMEJA MANFRED , MÜLLER WOLFGANG 
Published: February 2007

AbstractModern assessment of posture and motion involves the use of wide bandwidth piezoresistive accelerometers. The direct current (DC) component allows for assessment of slow motion and change in position referring to the gravitational axis; the alternating current (AC) component, calibrated in g, represents acceleration along the sensitive axis of the device. A method study was designed to evaluate the division in DC and AC components, reliabilities, discrimination between conditions, and detection of types of physical activities. Recordings were made in 26 student participants for eight conditions: sitting, standing, lying supine, sitting and typing on a PC keyboard, walking, climbing stairs, walking downstairs, and cycling. This procedure was repeated in reversed order. A classification of physical activities according to the eight conditions (first trial) and based on four parameters, that is DC components trunk, thigh, and lower leg and AC component trunk, was correct in almost 100% of patterns, when applied to the second trial.
An in vivo comparison of two circumferential penile strain gauges: The introduction of a new calibration method
Authors: JANSSEN ERICK , VISSENBERG MARIETTE , VISSER SAMBHAVO , EVERAERD WALTER 
Published: February 2007

AbstractThis study assessed the comparability of two types of penile strain gauges using both a circular and a newly developed oval calibration device. A group of 25 sexually functional participants places both an electromechanical and an indium/gallium‐in‐rubber strain gauge on the penis and viewed an erotic film. The electromechanical gauge as calibrated on the circular device resulted in greater penile circumference changes than the indium/gallium‐in‐rubber gauge. Mean circumference changes were not different for the two strain gauges when the oval calibration device was used. The use of an oval calibration device improves ecological validity of calibration of penile strain gauges. Standard inclusion of this method in studies on male sexual response will increase comparability of research findings.
The effect of unconditional stimulus modality and intensity on blink startle and electrodermal responses
Authors: SIDDLE DAVID A. T. , LIPP OTTMAR V. , DALL PATRICIA J. 
Published: February 2007

AbstractAttentional accounts of blink facilitation during Pavlovian conditioning predict enhanced reflexes if reflex and unconditional stimuli (US) are from the same modality. Emotional accounts emphasize the importance of US intensity. In Experiment 1, we crossed US modality (tone vs. shock) and intensity in a 2 × 2 between‐subjects design. US intensity but not US modality affected blink facilitation. In Experiment 2, we demonstrated that the results from Experiment I were not due to the motor task requirements employed. In Experiment 3, we used a within‐subjects design to investigate the effects of US modality and intensity. Contrary to predictions derived from an attentional account, blink facilitation was larger during conditional stimuli that preceded shock than during those that preceded tones. The present results are not consistent with an attentional account of blink facilitation during Pavlovian conditioning in humans.
Cerebral processing of words and the development of chronic pain
Authors: KNOST BÄRBEL , FLOR HERTA , BRAUN CHRISTOPH , BIRBAUMER NIELS 
Published: February 2007

AbstractThe processing of pain‐related, body‐related, and neutral words was assessed in individuals with prechronic pain and matched healthy controls. Integrated surface electromyogram, heart rate, skin conductance level, and visual event‐related potentials from 11 electrode sites were recorded during the presentation of three word types at perception threshold. Startle responses were recorded from words presented above perception threshold. The patient and control groups did not differ in recognition performance. Pain‐related words evoked an enhanced early component (N100) of the visual event‐related potential only in the prechronic pain group. In both groups the late slow wave and the startle response were enhanced for body‐ and pain‐related words compared with those for neutral words. All word types elicited larger late positivities in the prechronic pain group and in the right compared with the left hemisphere. These data suggest differential cortical processing of pain‐related material in persons at a prechronic pain stage.