bluuebunny/crossref_metadata_2025_split huggingface dataset:
Brain Generators Implicated in the Processing of Auditory Stimulus Deviance: A Topographic Event‐Related Potential Study
Authors: Giard Marie‐Hélène , Perrin François , Pernier Jacques , Bouchet Patrick 
Published: February 2007

ABSTRACTThe neurophysiological mechanisms underlying mismatch negativity (MMN) can be inferred from an examination of some of the brain generators involved in the process of this event‐related potential (ERP) component. ERPs were recorded in two studies in which the subjects were involved in a selective dichotic listening task. Subjects were required to silently count rare stimuli deviating in pitch from a sequence of standard stimuli in one ear, while ignoring all the stimuli (standards and deviants) delivered randomly to the other ear. The results showed that, in all cases, the negative wave elicited by the deviant stimuli showed the highest amplitudes over the right hemiscalp irrespective of the ear of stimulation or the direction of attention. Scalp radial current density analysis showed that this asymmetric potential distribution could be attributed to the sum of activities of two sets of neural generators: one temporal, located in the vicinity of the primary auditory cortex, predominantly activated in the hemisphere contralateral to the ear of stimulation, and the other frontal, involving mainly the right hemisphere.The results are discussed in light of Näätänen's model: we suggest the dissociation of two functional processes on the basis of activity of distinct brain areas: a sensory memory mechanism related to the temporal generators, and an automatic attention‐switching process related to the frontal generators.
Acute Emotional and Cardiovascular Effects of Stressful Mental Work During Aerobic Exercise
Authors: Roth David L. , Bachtler Shawn D. , Fillingim Roger B. 
Published: February 2007

ABSTRACTThe acute effects of engaging in challenging mental work during a single session of aerobic exercise were examined on measures of subjective mood and cardiovascular function. Fifty‐seven female subjects were randomly assigned to participate in either a 10‐min aerobic exercise condition or a no‐exercise control condition. Half of the subjects in each group performed digits backward problems during this time period, and no mental stressors were presented to the other subjects. The results indicated that the exercise and mental stress conditions had additive effects on subjective anxiety levels and on cardiovascular responses during exercise. Both exercise and mental stress increased heart rate. In addition, exercise had anti‐anxiety and vasodilative effects, but both of these influences were attenuated by opposing main effects for mental stress exposure. No effects were found for exercise on measures of cardiovascular reactivity to a later digits backward stressor. The results are consistent with previous research in suggesting that exposure to mental stressors during aerobic exercise provides no acute psychological benefits but attenuates some of the mood improvements and vasodilative effects of the exercise activity.
The Processing of Temporal Intervals Reflected by CNV‐Like Brain Potentials
Authors: Elbert Thomas , Ulrich Rolf , Rockstroh Brigitte , Lutzenberger Werner 
Published: February 2007

ABSTRACTThe present study employed event‐related potentials (ERPs) of the brain to improve the understanding of temporal processing. A reproduction paradigm was realized by presenting a visual stimulus (illuminated screen) for intervals of varying length. A few seconds after presentation of such standard intervals the visual stimulus was switched on again and subjects were asked to reproduce the duration of the standard interval by turning off the illumination after a corresponding interval had elapsed. The length of standard intervals varied randomly with each of the following lengths being presented 20 times: 1, 2, 3, 4, 6, and 8 s. Reproduction was accurate for standard intervals up to 3 s but deteriorated with increasing interval length. Brain potentials during reproduction intervals of 1–3 s differed from those recorded during the longer intervals. A CNV‐like slow negative shift developed during the shorter reproduction intervals. Negativity was reduced or even absent, when subjects had to reproduce standard intervals of 4 s or longer. The ERP results suggest that intervals shorter than 3–4 s may evoke a processing mode that is qualitatively different from the one dominating when periods in the range of several seconds have to be processed.
EEG Slow Wave Activity, REM Sleep, and Rectal Temperature During Night and Day Sleep in Morning‐Type and Evening‐Type Subjects
Authors: Kerkhof Gerard A. , Lancel Marike 
Published: February 2007

ABSTRACTDuring 3 baseline nights (2 for adaptation) and during 3 days of a sleep‐wake reversal, electrophysiological characteristics of sleep and rectal temperature were recorded in 8 morning‐type (M‐type) and 8 evening‐type (E‐type) subjects, living in a quiet sleep laboratory. Outcomes of visual sleep scoring revealed the following general tendencies for day‐sleep as compared to night‐sleep: shorter sleep latencies, shorter REM (rapid eye movement sleep) latencies, advance of the time of maximum REM duration, increased duration of slow wave sleep, more intermittent wakefulness, and decreased subjective sleep quality. Furthermore, for the M‐types consistently shorter sleep latencies and—for day‐sleep—longer REM latencies were observed than those for the E‐types. With regard to the parabolic time course of REM duration, M‐types appeared to be relatively phase advanced, in particular for their day‐sleep. In addition, subjective sleep quality was consistently higher for the M‐types, with the exception of the first day‐sleep. The temporal distributions of EEG delta (0.5–3.5 Hz) energy over the first four NREM/REM cycles of day‐sleep all deviated from a monotonically decreasing trend. Compared to night‐sleep the M‐types showed a relative increase of delta energy for Cycle 2, whereas for the E‐types a relative increase for Cycles 3 and 4 was observed. An analysis of delta energy, employing a pattern‐recognition technique independently from visual sleep scoring, revealed an overall faster rate of accumulation for the M‐types. Following sleep onset, rectal temperature showed a decrement, which was larger for the M‐types. Moreover, rectal temperature and delta energy were negatively related, as indicated by a negative mean intraindividual correlation. These results are discussed in relation to the characteristic sleep‐wake behavior of M‐types and E‐types.
The Effect of Repeated Testing on ERP Components During Auditory Selective Attention
Authors: Shelley Anne Marie , Ward Philip B. , Michie Patricia T. , Andrews Sally , Mitchell Penny F. , Catts Stanley V. , McConaghy Nathaniel 
Published: February 2007

ABSTRACTThe present study examined long‐term repetition effects on human auditory event‐related potentials (ERPs). ERPs were recorded from subjects performing the same multidimensional auditory selective attention task on six separate occasions spaced one week apart. The task required subjects to attend to tones that varied along the dimensions of location (L), pitch (P), and duration (D) and to detect prespecified target (L+P+D+) combinations of these attributes. Processing negativity (PN) between 100–400 ms did not change in amplitude or onset latency as a function of repeated experience with the task. In contrast, two measures of “very late” PN were reduced with practice. Specifically, the location effect measured over the 400–700‐ms epoch was significant only for Weeks 1 and 2, and the separation of the L+P+D‐ ERP from other D‐ ERPs, measured over the 700–1000‐ms epoch, was significantly reduced from Week 1 to Week 2. A late negative component (700–1000 ms) elicited by correctly identified targets increased between Weeks 1 and 2, consistent with subjects adopting the strategy of rehearsal of the target itself rather than the L+P+D‐ standard. P2 amplitude increased significantly for all standards, possibly due to decreased latency jitter in later weeks. N1 latency became significantly shorter over weeks, reflecting either increasing confidence in stimulus discrimination with repeated testing or the overlapping of an unchanging N1 with an increasing P2.
Subjective and Objective Measures of Sleepiness: Effect of Benzodiazepine and Caffeine on Their Relationship
Authors: Johnson Laverne C. , Freeman Charles R. , Spinweber Cheryl L. , Gomez Steven A. 
Published: February 2007

ABSTRACTAs part of a larger project on the effects of benzodiazepine and caffeine on daytime sleepiness, performance and mood, this study examined the relationship among the Multiple Sleep Latency Test, lapses during a tapping task, a Visual Analog Scale, and the Stanford Sleepiness scale. Subjects were 80 male, adult nonsmokers aged 20.3±2.7 years. The Multiple Sleep Latency Test, Stanford Sleepiness Scale, and the Visual Analog Scale were obtained at two‐hour intervals beginning at 0700 h and ending at 1700 h. The tapping task (lapses) was administered each day at 0600 h, 1000 h, and 1400 h. A lapse was a 3‐s or greater pause between taps. Correlations between the Multiple Sleep Latency Test and subjective (Visual Analog Scale and the Stanford Sleepiness Scale) measures were significant at 0600 h, but became nonsignificant as the day progressed. Correlations between lapses and the two subjective measures were generally nonsignificant. The two objective measures were significantly correlated in the total group but not in all treatment groups. The subjective measures were significantly correlated in the total sample and in each treatment group. This study reaffirms the importance of time of day when measuring sleepiness, and suggests that subjective and objective measures may measure different aspects of sleepiness.
Modulation of Slow Cortical Potentials by Instrumentally Learned Blood Pressure Responses
Authors: Elbert Thomas , Roberts Larry E. , Lutzenberger Werner , Birbaumer Niels 
Published: February 2007

ABSTRACTWe assessed whether instrumentally‐learned pressor responses inhibit electrocortical acitivity, as predicted by learning theories of idiopathic hypertension. Subjects received beat‐by‐beat feedback for increases and decreases in mean arterial pressure measured from the finger (Peñáz method). Slow potentials were recorded from the midsagittal line during the final training session. Also recorded at this time were heart rate, eye movements, respiration, and post‐session verbal reports of the subject's control strategies. Thirteen of 14 subjects differentiated blood pressure increases and decreases at p<.05 or better during the final session (within‐subject discriminative operant procedure). Slow potentials were less negative on blood pressure increase compared to decrease trials at all midsagittal sites (p<.02), indicating relative cortical inhibition by pressor responses. This effect occurred even though subjects reported tensing of muscles on increase trials (p<.01), a behavioral activity previously associated with augmented rather than diminished cortical negativity. On increase trials slow potentials shifted toward positivity just prior to heart rate deceleration (the latter effect confirming activation of the baroreceptors).
Mismatch Detection and the Latency of Temporal Judgments
Authors: Novak Gerald , Ritter Walter , Vaughan Herbert G. 
Published: February 2007

ABSTRACTEvent‐related potentials were recorded in two auditory tasks involving the discrimination of pitch or duration of binaurally presented tones. Frequently‐presented nontarget tones, when compared to the same tones in a simple reaction time task, elicited two negative peaks, NA1 and NA2, followed by a positive peak, nontarget positivity. Infrequently‐presented target tones, when compared to the nontargets, elicited mismatch negativity (MMN), followed by N2 and P3b. The peak latencies of NA1 and NA2 did not differ between the pitch and duration tasks, but the duration of NA1 and the peak latencies of mismatch negativity, N2, and P3b, as well as reaction time, increased in parallel for the duration task. It is proposed that the NA1‐nontarget positivity sequence reflects the initiation, maintenance, and termination of an attention‐modulated process, which is required for the performance of an auditory discrimination task, and that the MMN‐N2‐P3b sequence reflects a process elicited by infrequently‐presented targets, which is the main determinant of reaction time under these testing conditions.
Event‐Related Potentials and the Identification of Deviant Visual Stimuli
Authors: Czigler István , Csibra Gergely 
Published: February 2007

ABSTRACTThe effects of deviant visual stimuli on event‐related potentials were investigated in a counting task (Experiment 1) and in a reaction time task (Experiment 2). In Experiment 2 the interstimulus interval was either short or long (340 vs. 1020 ms). The stimuli (two angles within a frame) were frequent (Standard) or deviant (differing from the Standard either in the orientation of the two angles, or in the thickness of the frame, or in both of these features). In various conditions the target stimuli were defined by one of the deviant features or by the conjunction of these features. Subjects were more accurate in the counting task, and the reaction time was shortest when the target feature was the deviant angle orientation. Performance was lowest for the conjunction of the deviant features. The deviant angle orientation elicited a posterior negative wave in the 140‐180 ms range. As the interstimulus interval increased, the magnitude of this component decreased. All stimuli with relevant (attended) deviant features elicited another posterior negative wave in the 180–260 ms range as well as an anterior positivity with similar latency. When the interstimulus interval was short, and the only target was the Conjunction Deviant, the summed occipital activity to the relevant features of deviant nontarget stimuli was larger than the negativity to the Conjunction Deviant. Target stimuli elicited late positive waves, which were sometimes preceded by central negativity.
The 24‐Hour Sleep Propensity Function: Experimental Bases for Somnotypology
Authors: Lavie Peretz , Zvuluni Amir 
Published: February 2007

ABSTRACTThe present study investigated the temporal structure of sleep propensity during 48 hours using an ultrashort 7‐min sleep/13‐min wake cycle. Eight subjects were tested under two experimental conditions of either attempting sleep, or resisting sleep after a monitored night in the laboratory. Electrophysiological recordings were carried out during the 7‐min trials. The temporal structure and the overall level of sleepiness of the 48‐hour sleep propensity functions calculated from the amount of total sleep in each trial revealed a high within‐subjects stability. This was found both across the two days of the study within conditions, and across conditions. Also, diurnal levels of sleepiness were systematically related to nocturnal sleep parameters. Subjects having short nocturnal sleep latencies and higher sleep efficiencies slept more during the day. It is proposed that the structure and level of the sleep propensity function can be used to characterize individuals along two dimensions of somnotypology: “morningness‐eveningness” and “sleepy‐alert.”
Reliable responses to a cardiovascular reactivity protocol: A replication study in a biracial female sample
Authors: KAMARCK THOMAS W. , JENNINGS J. RICHARD , STEWART CHRISTOPHER J. , EDDY MICHAEL J. 
Published: February 2007

AbstractThis replication study was designed to examine the reliability of individual differences in cardiovascular responsivity to a standardized PC‐based cognitive task protocol (Kamarck et al., 1992) in a female community sample. Thirty women, both black and white (ages 25–44 years), were administered the protocol twice with a 1‐month retest interval using a mobile laboratory at a community‐based testing site. Measures of heart rate and blood pressure reactivity were obtained comparing assessments taken at rest and during three protocol tasks. Preejection period, stroke volume, and total peripheral resistance changes were estimated using impedance cardiography assessments. As in previous studies with males, individual differences in heart rate and systolic and diastolic blood pressure responses to the protocol were highly reliable (.80 or greater) when data were aggregated across three tasks and two testing sessions. Reliability of cardiac contractility (preejection period) and stroke volume changes to these tasks exceeded .70. This reactivity assessment procedure has now produced reliable results in three studies and appears to be exportable across diverse samples and settings.
Optimal digital filters for long‐latency components of the event‐related brain potential
Authors: FARWELL LAWRENCE A. , MARTINERIE JACQUES M. , BASHORE THEODORE R. , RAPP PAUL E. , GODDARD PHILIP H. 
Published: February 2007

AbstractA fundamentally important problem for cognitive psychophysiologists is selection of the appropriate off‐line digital filter to extract signal from noise in the event‐related brain potential (ERP) recorded at the scalp. Investigators in the field typically use a type of finite impulse response (FIR) filter known as moving average or boxcar filter to achieve this end. However, this type of filter can produce significant amplitude diminution and distortion of the shape of the ERP waveform. Thus, there is a need to identify more appropriate filters. In this paper, we compare the performance of another type of FIR filter that, unlike the boxcar filler, is designed with an optimizing algorithm that reduces signal distortion and maximizes signal extraction (referred to here as an optimal FIR filter). We applied several different filters of both types to ERP data containing the P300 component. This comparison revealed that boxcar filters reduced the contribution of high‐frequency noise to the ERP but in so doing produced a substantial attenuation of P300 amplitude and, in some cases, substantial distortions of the shape of the waveform, resulting in significant errors in latency estimation. In contrast, the optimal FIR filters preserved P300 amplitude, morphology, and latency and also eliminated high‐frequency noise more effectively than did the boxcar filters. The implications of these results for data acquisition and analysis are discussed.
Effects of stimulus preexposure and intermodality change on electrodermal orienting
Authors: SIDDLE DAVID A. T. , LIPP OTTMAR V. , DALL PATRICIA J. 
Published: February 2007

AbstractPrevious research has indicated that an intermodality change trial presented after a habituation series elicits larger orienting responses than does the first stimulus of that series. Experiment 1 (N= 48) investigated whether this effect was still present if the change stimulus was not novel but was presented once prior to the habituation series. Two groups of subjects were presented with a series of 24 tones or vibrotactile stimuli. Trial 25 was an intermodality change test trial for half of the subjects in each group (change), whereas the remaining subjects received an additional habituation stimulus (no change). Prior to the habituation trials, each subject was exposed once to the test stimulus used in the change condition. Although response magnitude on the test trial was larger in the change condition than in the no‐change condition, test trial response magnitude did not exceed that on the first trial of the habituation series. In Experiment 2 (N= 84), one group was preexposed to the test stimulus, another was preexposed to an experimentally irrelevant stimulus, and a third received no stimulus prior to habituation training. Test trial response magnitude was larger than responses to the first stimulus of habituation in the change group that was not exposed to a stimulus prior to habituation but not in the preexposed groups. Preexposure to a stimulus prior to habituation training abolished the intermodality change effect even when the test stimulus was novel. The present results pose problems for noncomparator theories of habituation and support the notion that anticipatory processes are important in orienting and habituation.
Autonomic cardiac control. II. Noninvasive indices and basal response as revealed by autonomic blockades
Authors: CACIOPPO JOHN T. , BERNTSON GARY G. , BINKLEY PHILIP F. , QUIGLEY KAREN S. , UCHINO BERT N. , FIELDSTONE ANNETTE 
Published: February 2007

AbstractHeart period, systolic time intervals, low and high frequency heart period variability, blood pressure, and respiration were measured in female subjects under three drug conditions (saline, atropine sulfate, metoprolol) while sitting and standing on three consecutive days. Following preinfusion baseline recordings, saline, metoprolol (14 mg), or atropine sulfate (2 mg) was infused for 15 min (by using a double‐blind procedure). Recordings were taken during a postinfusion baseline and in response to an orthostatic stressor (standing versus sitting postures). At the end of the metoprolol session, atropine sulfate was infused and responses were monitored during the post‐infusion (i.e., double blockade) baseline and during orthostatic stressor. Analyses of the blockade data revealed that the preejection period (PEP) reflected sympathetic but not vagal influences on the heart, and high frequency (HF, 0.12–0.40 Hz) heart rate variability (respiratory sinus arrhythmia) reflected vagal but not sympathetic influences on the heart. No other measure provided a specific index of the tonic sympathetic or vagal activation of the heart. Postinfusion PEP under saline predicted individual differences in postinfusion cardiac sympathetic activation, whereas postinfusion heart period (but not HF variability) under saline predicted individual differences in postinfusion cardiac vagal activation.
The effect of D‐amphetamine, clonidine, and yohimbine on human information processing
Authors: HALLIDAY ROY , NAYLOR HILARY , BRANDEIS DANIEL , CALLAWAY ENOCH , YANO LOVELLE , HERZIG KAREN 
Published: February 2007

AbstractTwelve subjects were tested with D‐amphetamine, yohimbine, clonidine, and a placebo on a task with two levels of stimulus and two levels of response complexity. The purpose of this study was to test the hypothesis that noradrenergic durgs affect early stimulus processes. D‐amphetamine speeded reaction time (RT), clonidine slowed it, and yohimbine had no effect. D‐amphetamine and yohimbine decreased N1 latency and clonidine increased it. D‐amphetamine and yohimbine decreased P3 latency and clonidine increased it but, in each case, only when latency estimates were based on single trials, not on averages. D‐amphetamine's effect on RT, not P3, as measured by the average, is consistent with previous results. Single trial measures appear more sensitive. Speeding of N1 and single‐trial P3 data indicate that noradrenergic durgs affect processing of early (visual) information. D‐amphetamine's speeding of single‐trial P3 estimates was attributed to its noradrenergic actions. Yohimbine's speeding of P3 without changing RT is consistent with neural net (parallel) simulations but not with a serial model. These findings support the assumption that different neurotransmitters modulate specific cognitive processes.