bluuebunny/crossref_metadata_2025 huggingface dataset:
Graphical and Statistical Techniques for Cardiac Cycle Time (Phase) Dependent Changes in Interbeat Interval
Authors: Jennings J. Richard , van der Molen Maurits W. , Somsen Riek J.M. , Ridderinkhof K. Richard
Published: February 2007

Cardiac cycle time effects refer to the relative lengthening or shortening of a single cardiac cycle as a function of when in the cycle brief sensorimotor events occur. These effects may provide short‐latency measures of cardiac sensitivity to psychological events. Conventional representations have, however, failed to clearly separate changes in interbeat interval due to cycle time—i.e., phase dependent changes—from other types of change. This paper advocates a particular technique of plotting to solve these representation problems. Heartbeat timing is represented in real time and in the context of beats both preceding and following the event of interest. The plot, a phase‐sensitive plot, conceptualizes phase‐sensitive (cardiac cycle time) effects as a change in linear or higher order trend. Thus, an adaptation of trend analysis is proposed as an efficient statistical analysis that follows directly from the proposed representational technique.
The Startle Eyeblink Response to Low Intensity Acoustic Stimuli
Authors: Blumenthal Terry D. , Goode Christopher T.
Published: February 2007

Four experiments were conducted to investigate the acoustic startle response to stimuli of low intensities. Eyeblink responses (integrated EMG from orbicularis oculi) were measured from male and female college students. Experiment 1 compared tone and noise stimuli varying in intensity (50 and 60 dB(A) SPL), with noise stimuli producing greater response amplitude and probability than tone stimuli. Experiment 2 was designed to investigate temporal summation of low intensity stimuli using single and paired 70dB(A) SPL broadband noises, and an onset‐to‐onset interval between the brief stimuli in a pair equal to the duration of the single stimuli. Increasing the duration of single stimuli resulted in larger responses, illustrating temporal summation. Experiment 3 used 60 and 70 dB(A) SPL broadband noise varying in rise/fall time, with faster‐rising stimuli producing larger responses, and more intense stimuli producing larger and more probable responding. Experiment 4 employed the startle modification paradigm using 60 and 70 dB(A) SPL broadband noises as startle stimuli and a 50dB(A) SPL tone as a prepulse. Response amplitude and probability to both 60 and 70 dB(A) SPL stimuli were significantly inhibited by the 50dB(A) SPL prepulse. These studies show that the acoustic startle response is more sensitive than previously thought, and the elicitation of startle by low intensity stimuli argues against the limitation of the startle reflex as a high intensity phenomenon. These findings can increase the application of this response system by showing that startle stimuli need not be of high intensity, because reliable and differential startle can be elicited and modified at relatively low stimulus intensities.
Effects of Inter‐Item Lag on Word Repetition: An Event‐Related Potential Study
Authors: Karayanidis Frini , Andrews Sally , Ward Philip B. , McConaghy Neil
Published: February 2007

Prior exposure to a word can greatly facilitate performance to subsequent presentations of that word. ERP studies have shown that this facilitation is associated with an attenuation of a negative peak normally occurring around 400 ms poststimulus. Recent studies have interpreted this repetition effect as reflecting either lexical access or episodic memory mechanisms. However, there is now increasing evidence that neither of the above mechanisms alone can fully account for repetition effects. The present experiment recorded ERPs to immediate and delayed word repetition during a lexical decision task in order to investigate the time‐course of ERP repetition effects. Immediate repetition was found to produce greater response facilitation than delayed repetition. The ERP waveforms of both immediate and delayed word repetition diverged from that of initial word presentation at approximately 300 ms poststimulus. The waveforms for repeated words separated around 400 ms poststimulus with immediate repetition showing a more rapid resolution of negativity and earlier late positivity than delayed repetition. It is suggested that the negativity may reflect processes involved in the overall activation contributing to word recognition, whereas the late positivity may be related to the repetition of stimulus categorization and decision processes.
An ERP‐Based, Control‐Question Lie Detector Analog: Algorithms for Discriminating Effects Within Individuals' Average Waveforms
Authors: Rosenfeld J. Peter , Angell Andrea , Johnson Mary , Qian Jia‐HE
Published: February 2007

Two experimental, P3‐based analog control question tests were run. In both, guilty subjects were presented with a set of seven phrases describing antisocial acts of which they were innocent, plus one phrase describing a guilty act (the analog relevant question), and one act to which a “yes” response (yes‐target stimulus) was required to assure attention. Innocent subjects (run only in Experiment 1) saw all innocent acts plus the yes‐target act. Thus nine acts were seen by guilty and innocent subjects. In both experiments, all subjects had to selectively review their guilty acts privately. Also in both experiments, all subjects were especially questioned about four acts of which guilty subjects were known to be innocent of all but one, and of which innocent subjects were known to be innocent of all. (These falsely accused acts were regarded as control question analogs.) In Experiment 1, the private review and rehearsal took place on the same day as the main test. In Experiment 2, one subgroup (delay‐only) of guilty subjects was run as in Experiment 1, except that the private review‐rehearsal was separated from the main run by 7–14 days. Another subgroup (delay‐rehearsal) of guilty subjects was run just as was the subgroup delay‐only, except that the delay‐rehearsal subgroup additionally received a non‐selective additional interrogation/rehearsal on the delayed main run day. Parietally maximal P3 responses were obtained to yes‐target items in all groups. In Experiment 1, only in the guilty group was the relevant‐minus‐control P3 amplitude difference significant. In Experiment 2, the difference was significant only in the delay‐rehearsal subgroup. A four‐step algorithm (involving relevant‐control amplitude differences and relevant target vs. control‐target cross‐correlations) was used to assess effects within individuals. In Experiment 1, 12 of 13 guilty subjects and 13 of 15 innocent subjects were correctly diagnosed. In Experiment 2, 3 of 8 delay‐only subjects and 7 of 8 delay‐rehearsal subjects were correctly diagnosed. In Experiment 2, the relevant‐minus‐control group P3 amplitude difference was significant in the delay‐rehearsal but not in the delay‐only subgroup. The results suggest that temporally proximal, non‐selective rehearsal procedures are sufficient to activate personal knowledge of a salient (oddball). P3‐generating stimulus phrase, and that even selective rehearsal of guilty acts is not sufficient without temporal proximity.
Weak Sensory Stimuli Induce a Phase Sensitive Bradycardia
Authors: Jennings J. Richard , Molenvan der Maurits W. , Somsen Rlek J.M. , Brock Kay
Published: February 2007

We attempted to demonstrate that significant perceptual stimuli would induce different degrees of heart rate deceleration depending on when (phase) in the cardiac cycle they occurred. Relative to previous work, we concurrently examined a number of factors that might alter the amplitude of such a cardiac cycle time effect. Stimulus intensity and presence or absence of a speeded response were manipulated. Liminal stimuli and a perceptual rather than motor set were expected to maximize any cardiac cycle time effect. Respiratory phase, length of average interbeat interval, and number of trials were also investigated. Twenty‐four college aged, male volunteers were randomly separated into equal groups receiving instructions either to judge which of two weak visual stimuli occurred or to execute a speeded, discriminative response to the stimuli. Discriminative stimuli were presented at either 0, 150, 250, 350, or 500 ms after the R‐wave of the electrocardiogram. Stimuli were presented with an intensity that had yielded either 63% or 90% correct detections in a prior psychophysical assessment. A phase dependent deceleration occurred after both intensities of stimuli. Poststimulus deceleration was greater for stimuli in early to mid cycle as suggested by earlier work. As expected, this result was clear when the stimuli were presented during the expiratory phase of respiration. Neither perceptual/motor set nor stimulus intensity altered the phase sensitive deceleration. Thus, phase sensitive deceleration was confirmed using demanding sensory stimuli and an improved representational technique.

Integrative Summary

By controlling response speed and graphically separating anticipatory and stimulus induced effects, we have demonstrated primary bradycardia. Poststimulus deceleration was a decreasing function of time of stimulus presentation within the cardiac cycle. As expected, primary bradycardia was present during the expiratory phase, but not the inspiratory phase of respiration. Manipulations designed to enhance perceptual analysis altered performance but failed to significantly alter the cardiac response. Thus, we were able to produce a robust primary bradycardia, but were unable to alter the strength of primary bradycardia by manipulation of perceptual variables.
Cortical Activity Elicited by Changes in Auditory Stimuli: Different Sources for the Magnetic N1OOm and Mismatch Responses
Authors: Sams Mikko , Kaukoranta Elina , Hämäläinen Matti , Näätanen Risto
Published: February 2007

Magnetic responses to frequent and infrequent auditory stimuli, all presented in the same stimulus block in randomized order, were recorded. The standard stimuli, comprising 90% of all the stimuli, were 100‐ms, 1000 Hz, 90dB sinusoidal tone bursts. There were three deviant tones, each presented at a probability of 3.3%, which differed from the standard tone on one dimension only: frequency deviant (1500 Hz), intensity deviant (67dB SPL), or duration deviant (50 ms). All mismatch fields, i.e., responses elicited by different deviants, as well as N100m to the standards and deviants, could be explained by neural activity in the supratemporal auditory cortex. The source of N100m to standards and deviants was significantly posterior to the sources for the three different mismatch fields. The mean locations of the equivalent dipoles for the different mismatch fields did not differ significantly from each other, but some differences were found for individual subjects.
A Major Effect of Recording Site on Measurement of Electrodermal Activity
Authors: Scerbo Angela Scarpa , Freedman Lauren Weinstock , Raine Adrian , Dawson Michael E. , Venables Peter H.
Published: February 2007

Although the medial phalanx has been recommended as the preferred site for recording skin conductance activity, a review of articles published in Psychophysiology indicates that a large minority (34%) of studies employ the distal phalanx. Informal observations also suggest that the distal site may be more reactive than the medial site. This study formally tests this observation by recording skin conductance from both medial and distal phalanges. Twenty‐four right‐handed subjects (12 male, 12 female) were exposed to a series of 10 orienting and defensive stimuli. Electrodes were placed on the fore and middle fingers of each hand, with distal sites used on one hand and medial sites on the other for each subject. Skin conductance amplitudes were 3.5 times larger at distal than medial sites (p<.002), while skin conductance levels were 2.08 times larger at distal sites (p<.0005). A significant Site × Stimulus interaction (p<.025) indicated that the distal site was more sensitive to habituation over trials and to increases in skin conductance amplitudes with increasing stimulus intensity than the medial site. On the basis of these findings it is recommended that distal sites be used in preference to medial sites in the recording of skin conductance activity.
Cardiovascular Reactivity in Type A and B Males to Mental Arithmetic and Aerobic Exercise at an Equivalent Oxygen Uptake
Authors: Delistraty Damon A. , Greene William A. , Carlberg Karen A. , Raver Karen K.
Published: February 2007

Cardiovascular hyperreactivity (i.e., response in excess of metabolic requirements) to psychologyical stress has been implicated in the development of coronary heart disease. The purpose of this study was to evaluate cardiovascular hyperreactivity to psychological stress in Type A and B subjects. Fifteen Type A and 15 Type B young men performed mental arithmetic and cycle ergometry tasks. Linear regressions were calculated for each dependent variable during exercise with oxygen uptake serving as the independent variable. All cardiovascular variables were significantly correlated (p<0001) with oxygen uptake during exercise. The regression equations obtained during exercise were then used to predict the value of each cardiovascular variable at the oxygen uptake level obtained during mental arithmetic for each person. Repeated measures ANOVA compared responses observed during arithmetic with responses predicted from exercise at an equivalent oxygen uptake in Type A and B subjects. Heart rate, total peripheral resistance, and mean arterial pressure were significantly greater (p<0001) and stroke volume was significantly lower (p<.0002) during arithmetic than during exercise, while Heather index, cardiac output, and arteriovenous oxygen difference did not differ significantly. No significant differences were found between Type A and B males. Results demonstrated that cardiovascular hyperreactivity was equally robust across Type A and B subjects.
Can Echoic Memory Store Two Traces Simultaneously? A Study of Event‐Related Brain Potentials
Authors: Winkler István , Paavilainen Petri , Näätänen Risto
Published: February 2007

The mismatch negativity, a component of the event‐related brain potential elicited by infrequent deviants in sequences of auditory stimuli, is presumably generated by an automatic mismatch process in a mechanism that compares the current stimulus to the trace of the previous one. The present study addressed the possible simultaneous existence of two such traces. Two equiprobable (45% each) frequent stimuli (“standards”), one of 600 Hz and the other of 700 Hz, were presented together with an infrequent (10%), “deviant” stimulus which was of differnet frequency in different blocks. These deviants elicited a mismatch negativity, though a smaller one than that obtained in corresponding blocks with only one standard stimulus. Two aspects of the present results from the blocks with two standard stimuli implicate two parallel stimulus traces in these blocks: 1) deviants elicited a mismatch negativity (MMN) of approximately the same amplitude when preceded by sequences of four identical standards as when preceded by sequences of four stimuli containing both standards; 2) in contrast to the one‐standard condition, the magnitude of stimulus deviance did not affect the MMN component elicited by the different deviants.
Symptom‐Specific Psychophysiological Responses in Chronic Pain Patients.
Authors: Flor Herta , Birbaumer Niels , Schugens Markus M. , Lutzenberger Werner
Published: February 2007

Symptom‐specific psychophysiologiocal responding was assessed in 20 chronic back pain patients, 20 patients suffering from temporomandibular pain and dysfunction, and 20 matched healthy controls. Surface EMG from the lower and upper back, the masseter, and the biceps muscles, and heart rate and skin conductance level were continuously recorded during adaptation, resting baseline, and stressful and neutral imagery phases. Univariate and multivariate analyses of variance were performed on raw data as well as data corrected for autocorrelation. The results showed significantly higher EMG reactivity which was lateralized to the left side at the patients site of pain but not distal sites. This hyperreactivity was observed only during stressful imagery. The healthy controls displayed a significantly higher response in heart rate, but skin conductance level was not significantly different. The results are interpreted as indicative of idiosyncratic muscular response patterns to personally relevant situations at the site of pain in patients suffering from chronic muscular pain.
Temporal stability of task‐induced cardiovascular, adrenergic, and psychological responses: The effects of race and hypertension
Authors: MILLS PAUL J. , BERRY CHARLES C. , DIMSDALE JOEL E. , NELESEN RICHARD A. , ZIEGLER MICHAEL G.
Published: February 2007

This study examined the test‐retest reliability of task‐induced responses of blood pressure, heart rate, norepinephrine, epinephrine, anger, and anxiety in 98 black and white normotensive and hypertensive individuals. Subjects completed three laboratory tasks (standing, mental arithmetic, and cold pressor) on two occasions 10 days apart. For all subjects, all baseline and test‐retest correlation coefficients were significant (rs = .23–.71; median = .58). Baseline‐adjusted (residual scores) reactivity test‐retest correlation coefficients were consistently smaller (rs = .02–.55; median = .36). In contrast to the white hypertensives, white normotensives, and black normotensives, the black hypertensives showed no significant baseline‐adjusted test‐retest correlation coefficients (rs =−.21–.40; median = .12). Epinephrine responses revealed a significant session by race interaction; blacks had 20% higher mean values and whites had 10% lower mean values upon retesting. The data suggest that race and hypertension may interact to affect the temporal stability of task‐induced responses to stressors.
Age‐related changes in scalp topography to novel and target stimuli
Authors: FRIEDMAN DAVID , SIMPSON GREGORY , HAMBERGER MARLA
Published: February 2007

Event‐related brain potentials (ERPs) were recorded from young, middle‐aged, and older adults to infrequent target and novel stimuli during a version of the oddball paradigm. Analyses of scalp distribution suggested that the shift to a more frontally oriented topography with increasing age was confined to the P3 component (as compared to N1 and P2) elicited by both target and novel stimuli. This first demonstration of an age‐related shift in the scalp distribution of the novelty P3 elicited by auditory stimuli was associated with an age‐related increase in the false‐alarm rate to novel stimuli. These age‐associated differences in scalp distribution and false‐alarm rate are consistent with a change in frontal lobe activity with increasing age.
An evaluation of the automaticity of sensory processing using event‐related potentials and brain‐stem reflexes
Authors: HACKLEY STEVEN A.
Published: February 2007

Selective attention effects on reflexes and evoked potentials are reviewed with the aim of evaluating three theories regarding sensory automaticity. (a) Theperipheral‐gating theory, which assumes that ignored stimuli can be filtered out soon after transduction, was tentatively rejected because neither auditory‐nerve nor retinal potentials are reliably affected by attention. (b) At the other extreme, the assumption that sensory analyses are obligatory and cannot benefit from attentional resources (i.e.,strong‐automaticity theory) was also rejected, because longer latency componets were found to be modifiable by attention. (c) Anintermediate theoryprovides the best fit to present electrophysiological data. The earliest sensory analyses are assumed to be strongly automatic and then, at forebrain levels, there is a transition from strong to weak automaticity (i.e., analyses are obligatory but modifiable by attention). This transition can begin as early as about 15 ms for audition and about 80 ms for vision.
The reliability of ERP components in the auditory oddball paradigm
Authors: SEGALOWITZ SIDNEY J. , BARNES KERRY L.
Published: February 2007

Nineteen adolescents (average age 15 years, 3 months) were tested and retested using a standard 40 target, auditory oddball ERP paradigm across an interval of 1 year, 10 months to determine reliability of the ERP components, both in terms of intersubject stability and score agreement and in terms of trait (between‐session reliability) versus state (within‐session reliability). Significant trait stability was found for the N100, P200, and P300 latencies (r= .48, .51, and .74, respectively), and for P300 amplitude (r= .62), supporting the P300 as a reliable measure, with the stability required for group research but not necessarily for clinical applications. Discussion and examples illustrate the application of reliability information to the planning and evaluation of ERP paradigms.
On the relation between cardiodynamics and heartbeat perception
Authors: SCHANDRY RAINER , BESTLER MICHAEL , MONTOYA PEDRO
Published: February 2007

The mediation of heartbeat perception by cardiodynamic parameters was investigated by experimentally introducing changes in heart performance. Twenty‐five subjects (14 women 11 men) underwent bicycle ergometric exercises (0–75 W) at different tilt angles (90°‐0°), After each of the 31 tilt/exercise phases, the following measures of cardiac performance were taken using impedance cardiography: stroke volume, Heather Index (as an indicator of contractile force), heart rate, and an estimate of the momentum of the ejected blood mass. Additionally, a heartbeat perception task was performed. The different tilt/exercise combinations induced profound changes in all cardiodynamic. measures, The correlation between heartbeat perception and cardiodynamic parameters was highest for “momentum”(r= 67) and for stroke volume (r= 59). From our data, we infer that intraindividually occurring changes in cardiac perception are mediated partially by characteristics of heart dynamics and that the source of these interoceptive signals lies in the heart or in its close vicinity.
Early and late VEPs for reading stimuli are altered by common binocular misalignments
Authors: SUTER PENELOPE S. , BASS BRENDA L. , SUTER STEVE
Published: February 2007

Effects of mild binocular anomalies on early and late evoked response complexes to word stimuli were examined in visual evoked potentials (VEPs) recorded over occipital cortex, Wernicke's area, and its right side homolog in university students with (fixation disparity group) and without (normal group) fixation disparity. Stimuli were monocularly or binocularly viewed words of a paragraph presented individually for 100 ms, one per second, and a binocular control condition without linguistic content. An early complex (P125‐N170) recorded at Oz and a late complex (N170‐late P) recorded from the t4emporoparietal placements were analyzed. The early complex as not influenced by linguistic content. Binocular stimuli generally resulted in larger early and late VEP amplitudes than did monocular stimuli except that the fixation disparity group had no binocular amplitude enhancement at Oz. Left hemisphere amplitude was greater than right for all conditions, more so for words than for nonlinguistic stimuli. For words, the left hemisphere advantage was significant only for the normal group. Relationships between basic visual processing and language processing in relation to early and late complexes are considered from several perspectives.
Startle reflex facilitation as a function of classical eyeblink conditioning in humans
Authors: FLATEN MAGNE ARVE
Published: February 2007

I investigated whether classical eyeblink conditioning increases the activating effect of the conditional stimulus (CS) on the relevant alpha motoneuron pool in the facial nucleus. The activating effect was measured by the reflex modification method, where startle reflexes, sharing the facial nerve motor pathway with conditional and unconditional eyeblink reflexes, were elicited in the presence of reinforced and nonreinforced CSs (CS+ and CS−). To reduce influences of conditional arousal on startle, a weak airpuff to the eye was used as unconditional stimulus and relatively short stimulus onset asynchronies (SOAs) of 300 and 600 ms were used in three startle tests presented while conditioning was in progress. Two groups (N= 72) received 100% or 0% reinforcement (Groups 100 and 0) of a tone CS+. The CS− was not reinforced. Three startle tests, consisting of acoustic startle probes presented alone and after CS+ and CS− onset, were conducted early, middle, and late in conditioning. Results showed increased startle reflex facilitation after CS+ onset in the late startle test in Group 100, indicating that startle increased as a function of classical conditioning. Although reflex facilitation at the 300‐ms SOA in Group 100 is consistent with the hypothesis that CS presentations activated motoneurons in the facial nucleus, the present study cannot itself definitively support this hypothesis. Reflex facilitation at the 600‐ms SOA in Group 100 could be influenced by conditional arousal.
Amplitude and bilateral coherency of facial and jaw‐elevator EMG activity as an index of effort during a two‐choice serial reaction task
Authors: VAN BOXTEL A. , JESSURUN M.
Published: February 2007

In earlier studies, positive but inconsistent relationships have been reported between mental effort and electro‐myogram (EMG) amplitude in task‐irrelevant limb muscles. In this study, we explored whether facial EMG activity would provide more consistent results. Tonic EMG activity of six different facial and jaw‐elevator muscles was bilaterally recorded during a two‐choice serial reaction task with paced presentation of auditory or visual signals. In Experiment 1, task load (signal presentation rate) was kept constant for 20 min at the level of the subject's maximal capacity. In Experiment 2, task load was increased in a stepwise fashion over six successive 2‐min periods from sub‐ to supramaximal capacity levels. EMG amplitude and coherency between momentary bilateral amplitude fluctuations were measured.

In Experiment 1, EMG amplitude of frontalis, corrugator supercilii, and orbicularis oris inferior showed a strong gradual increase throughout the task period, whereas task performance remained fairly stable. Orbicularis oculi, zygomaticus major, and temporalis EMG showed a much smaller increase or no increase. In Experiment 2, the first three muscles showed a fairly consistent increase in EMG amplitude with increasing task load. Orbicularis oculi and zygomaticus major were not active until task load became supramaximal. Effects of stimulus modality or laterality were not found in any experiment. These results are consistent with the notion that EMG amplitude of frontalis, corrugator, and orbicularis oris provides a sensitive index of the degree of exerted mental effort.
Memory template comparison processes in anhedonia and dysthymia
Authors: GIESE‐DAVIS JANINE E. , MILLER GREGORY A. , KNIGHT RAYMOND A.
Published: February 2007

Anhedonic subjects, potentially at risk for psychopathology because of a deficient ability to experience pleasure, have demonstrated a large N200 component in the event‐related brain potential (ERP). The present experiment attempted to determine the psychological significance of this finding in light of Näätänen's (1990) distinction between N2a and N2b subcomponents. Anhedonics were contrasted with controls and dysthymics, an at‐risk group reporting depression. Across groups, N2a was larger when a tone mismatched a longer run of preceding identical tones. Thus, an involuntary mismatch process appears to be intact in both at‐risk groups. However, the three groups produced distinct N2bs as a function of stimulus sequence. The N2b finding for anhedonics is consistent with Knight's (1984, 1992) model of early stimulus processing deficits in schizophrenia.
Probing the orienting response with startle modification and secondary reaction time
Authors: FILION DIANE L. , DAWSON MICHAEL E. , SCHELL ANNE M.
Published: February 2007

Current models of orienting suggest a relationship between the orienting response and attentional processing. This relationship was examined using two independent probe techniques to index attentional processing: secondary reaction time and startle eyeblink modification. Twenty‐eight college‐age subjects received intermixed presentations of to‐be‐attended and to‐be‐ignored tones. Skin conductance orienting responses were obtained during a subset of the tones. Each of the remaining tones contained either a secondary reaction time probe at lead intervals of 150 or 2,000 ms or a startle eyeblink probe presented at lead intervals of 120 or 2,000 ms. In addition, reaction time and startle probes also were presented during selected intertone intervals, and responses to these stimuli served as the baselines from which to compare changes in reaction time and blink amplitude produced by the attended and ignored tones. The results revealed that, compared with the ignored tones, the attended tones were associated with larger skin conductance orienting responses, greater blink inhibition at the 120‐ms lead interval, greater blink facilitation at the 2,000‐ms lead interval, and greater reaction time slowing at the 2,000‐ms lead interval. Consistent with previous findings, the ignored tone was associated with greater reaction time slowing than was the attended tone at the 150‐ms lead interval. The results support a relationship between elicitation of the skin conductance orienting response and attentional processes and suggest that the secondary reaction time and blink modification techniques may provide unique information regarding this relationship.
Is a stimulus conveying task‐relevant information a sufficient condition to elicit a stimulus‐preceding negativity?
Authors: DAMEN ERNST J. P. , BRUNIA CORNELIS H. M.
Published: February 2007

Movement‐preceding and stimulus‐preceding negativities were recorded when a movement was followed by one of three informative visual stimuli. The meaning of the visual stimulus alternated between (a) conveying a task‐relevant instruction about a subsequent time production task and (b) providing feedback (knowledge of results) about performance on the current time production task. In a control condition, premovement and postmovement scalp potentials were recorded when subjects made the same movements but in a voluntary, self‐paced manner. Under all conditions, movements were preceded by a movement‐preceding negativity, and neither the amplitude nor the lateral asymmetry of this negativity was affected by the subsequent presentation of either kind of informative stimulus. When the movement was followed by a stimulus conveying knowledge of results, the negativity in the postmovement epoch was enhanced, but this enhancement was not evident in epochs preceding instruction stimuli. We conclude that not all task relevant stimuli elicit a stimulus‐preceding negativity, and we provide a functional interpretation of this negativity in terms of emotional anticipation and the contingency of the stimulus on a previous event.
Heart rate and sustained attention during childhood: Age changes in anticipatory heart rate, primary bradycardia, and respiratory sinus arrhythmia
Authors: WEBER EDITH J. M. , VAN DER MOLEN MAURITS W. , MOLENAAR PETER C. M.
Published: February 2007

This study examined age changes in three aspects of heart rate responsivity elicited in an auditory oddball task; anticipatory heart rate change, primary bradycardia, and respiratory sinus arrhythmia. Three age groups (5‐, 7‐, and 9‐year‐old boys) were presented with series of target (15%) and standard (85%) tones. The results were consistent with the findings reported previously in the adult literature. Heart rate decreased in anticipation of the target tone. The morphology of anticipatory deceleration was somewhat different for the 5‐year‐olds compared to the older children. Stimuli presented during the early part of the cardiac cycle induced added deceleration, but this primary bradycardia did not differ between age groups. Respiratory sinus arrhythmia did not discriminate between age groups but was suppressed during the performance of the oddball task relative to base level. It was concluded that these three aspects of heart rate responsivity show developmental constancy rather than change.
Muscle tension in generalized anxiety disorder: Elevated muscle tonus or agitated movement?
Authors: HAZLETT RICHARD L. , McLEOD DANIEL R. , HOEHN‐SARIC RUDOLF
Published: February 2007

The purpose of this study was to investigate the amplitude characteristics of frontalis and gastrocnemius electro‐myographic (EMG) activity in clinically anxious and nonanxious populations. Eighteen women with generalized anxiety disorder (GAD) and 19 nonanxious women were compared during baseline, laboratory stressor, and recovery conditions. EMG mean levels were greater for the GAD group, but there were no group differences in EMG skewness. During the stressor the GAD group had a significant reduction in frontalis EMG variability. Gastrocnemius muscle activity for both groups during the stressor condition increased in mean levels and variability while decreasing in skewness. These results indicate that clinically anxious individuals have elevated muscular tonus and have reduced variability in frontalis activity during stressful tasks. Also, the gastrocnemius muscle exhibited a stressor reactivity, whereas the frontalis did not. This study presents an approach to EMG analysis that could be useful in distinguishing unique features of anxiety as well as other emotional disorders.
Neuroanatomical correlates of electrodermal skin conductance responses
Authors: TRANEL DANIEL , DAMASIO HANNA
Published: February 2007

We studied the electrodermal skin conductance responses (SCRs) of 36 subjects with well‐characterized lesions in various regions of the cerebral hemispheres. Several lesion loci were consistently associated with defective electrodermal responding: the ventromedial frontal region (right and left), the right inferior parietal region, and the anterior cingulate gyrus (right and left). Our findings provide direct information regarding neural correlates of skin conductance responses in humans.
Effects of data limitations on heartbeat detection in the method of constant stimuli
Authors: BRENER JASPER , RING CHRISTOPHER , LIU XIAOQING
Published: February 2007

In the method of constant stimuli applied to measuring heartbeat detection, subjects judge the simultaneity of heartbeats and exteroceptive comparison stimuli presented at various intervals after the R‐wave (0, 100, 200, 300, 400, and 500 ms). Using versions of this procedure, investigators have found that between 20% (Yates, Jones, Marie, & Hogben, 1985) and 54% (Brener, Liu, & Ring, 1993) of subjects can detect heartbeat sensations. Whereas Yates et al. used a single comparison stimulus on each trial and Brener et al. used 10, the present study examined whether this disparity in heartbeat detection performance could be attributed to the number of comparison stimuli presented on each trial. In each of 360 trials, 30 subjects judged the simultaneity of heartbeat sensations and tones following 1, 5, or 10 comparison stimulus presentations. Significantly fewer subjects met the criterion for heartbeat detection with I tone presentation (13%) than with either 5 (43%) or 10 (47%) tone presentations. It is concluded that a single stimulus presentation imposes data limitations that result in underestimation of the accuracy of heartbeat detection. The presentation of at least 5 stimuli in each trial alleviates this limitation.
Modulation of the acoustic startle response by film‐induced fear and sexual arousal
Authors: JANSEN DORINE M. , FRIJDA NICO H.
Published: February 2007

The response matching model of Lang, Bradley, and Cuthbert (1992) predicts startle reflex facilitation during negative relative to positive emotional states. Using slide and imagery paradigms, larger eyeblink responses to startle probes for unpleasant than for pleasant conditions have consistently been reported. The present study extended the previously observed relationship between valence and startle to more complex stimuli, namely 1‐min film fragments. Thirty‐three subjects viewed a sequences of 27 film fragments with neutral, negative (fearful), and positive (sexual) contents, presented in one of three mixed orders. Blink magnitude to brief bursts of white noise was larger during fearful fragments than during sexual fragments. Blink magnitudes habituated across successive film fragments, but the positive‐negative difference remained stable within film fragments and during the entire length of the videotape (approximately 40 min).
Energy expenditure and motor performance relationships in humans learning a motor task
Authors: SPARROW W. A. , NEWELL K. M.
Published: February 2007

The ability of human subjects to learn minimum energy‐demanding variants of biological motion was examined in three adult males trained to walk on hand and feet (creep) on a motor‐driven treadmill at constant speed (0.64 m/s) for 16 3‐min trials. Two subjects systematically decreased oxygen consumption and heart rate over trials. Following this acquisition phase, subjects completed walking and creeping trials at positive and negative treadmill grades and selected a freely chosen creeping grade that felt “most comfortable.” One subject selected a grade that was more efficient than those imposed. Oxygen‐consumption curves for walking and creeping converged with increasing positive grade, indicating that increased grade influences the metabolic energy viability of the task (creeping or walking). The acquisition data provide empirical support for the “principle of least effort” and lend support to the concept of a “comfort mode” in the execution of motor tasks.
The roles of stimulus novelty and significance in determining the electrodermal orienting response: Interactive versus additive approaches
Authors: BEN‐SHAKHAR GERSHON
Published: February 2007

Two competing approaches for the roles of stimulus significance and novelty in determining orienting responses (ORs) were tested and compared. According to the first, ORs to significant stimuli are determined by sets and expectations and are relatively independent of the contrast between the test stimulus and preceding stimuli, whereas responses to nonsignificant test stimuli are products of a Sokolovian match/mismatch process. According to an alternative approach, novelty and significance contribute independently and additively to the OR. Stimulus significance and novelty were independently manipulated in two experiments, and the electrodermal component of the OR was measured while sequences comprising compound pictorial or verbal stimuli were presented. Each sequence included a test stimulus that was either significant or neutral and was preceeded by several control stimuli. Novelty was manipulated by varying the contrast between the test and the control stimuli. The results revealing no interaction between stimulus significance and novelty were interpreted as supporting the theory proposed by Gati and Ben‐Shakhar (1990).
Attentional modulation of the mismatch negativity elicited by frequency differences between binaurally presented tone bursts
Authors: TREJO LEONARD J. , RYAN‐JONES DAVID L. , KRAMER ARTHUR F.
Published: February 2007

We examined the attentional sensitivity of the frequency‐change mismatch negativity (MMN). Subjects listened to a binaural mixture of a narrative and a series of tone bursts that included 1200‐Hz standards and two deviants (1000 and 1400 Hz). In the attend‐tones condition, subjects responded to one deviant and ignored the narrative. In the attend‐words condition, subjects responded to target words in the narrative and ignored the tones. Event‐related potentials (ERPs) were recorded for the tones, and differences waves (deviant ERPs minus standard ERPs) were computed. Two negative peaks in the difference waves, DNI (100–180 ms) and DN2 (200–300 ms), overlapped the known scalp distribution and latency of the MMN. Mean DN1 and DN2 amplitudes were greater in the attend‐tones condition than in the attend‐words condition. These data suggest that the frequency‐change MMN is modulated by nonspatial shifts of auditory attention.
Emotional modulation of skin conductance and eyeblink responses to a startle probe
Authors: VRANA SCOTT R.
Published: February 2007

In this study, I examined emotional modulation of the eyeblink, skin conductance, and cardiac responses to an acoustic startle (103 dB[A] white noise) probe. Twenty‐five female and 17 male undergraduates imagined pleasant, neutral, and fearful situations in a tone‐cued imagery procedure. Both the eyeblink and skin conductance responses to startle probes were potentiated (larger magnitude, shorter latency) during fear as compared with neutral and pleasant imagery. The amount of emotional modulation in these two response systems was significantly correlated both between and within subjects. The startle probe interrupted ongoing cardiac deceleration during the imagery task, but this interruption was not related to the emotional content of imagery.
Emotional expectancy: Brain electrical activity associated with an emotional bias in interpreting life events
Authors: CHUNG GEOFFREY , TUCKER DON M. , WEST PAULA , POTTS GEOFFREY F. , LIOTTI MARIO , LUU PHAN , HARTRY ANN L.
Published: February 2007

University students in either an optimistic or pessimistic mood state read brief stories of daily life events as event‐related brain potentials were collected during the final word of each story. For subjects in a pessimistic mood, a bias to expect negative outcomes was seen as an N400/P300 effect over posterior scalp regions. For subjects in an optimistic mood, a differentiation between good and bad outcomes was also observed, but it was specific to medial frontal areas. Analysis of single‐trial P300 latencies suggested that semantically incongruent and mood‐incongruent outcome words resulted in increased median latency of the late positive complex (LPC) and resulted in increased variability of LPC latency across trials.
Meta‐analysis of P300 normative aging studies
Authors: POLICH JOHN
Published: February 2007

The theoretical and empirical backgrounds for the utility of the P300 event‐related potential (ERP) as a measure of cognitive aging are summarized. P300 latency data from 32 different normative aging studies are then reviewed and assessed with meta‐analytic procedures. Evaluation of moderator variables indicates that sample characteristics, stimulus factors, and task conditions contribute significantly to the “normal” change in peak latency that occurs with aging. These findings are critiqued in the context of previous reports, and implications are outlined for future applications of ERPs to normative aging. It is concluded that P300 latency can provide useful information about cognitive aging but that specific variables must be considered to obtain more precise results.
The nature of the late positive complex within the olfactory event‐related potential (OERP)
Authors: PAUSE BETTINA M. , SOJKA BERNFRIED , KRAUEL KERSTIN , FERSTL ROMAN
Published: February 2007

The olfactory event‐related potential (OERP) has been described as being dependent on exogenous stimulus features, but no effect has been made to examine possible endogenous determinants. We wanted to separate exogenous and endogenous components of the OERP by using an olfactory oddball paradigm. A high concentration of citral was used as the target stimulus, and a low concentration was used as the standard stimulus. Odors were presented within a constantly flowing air stream. We found that the early components of the OERP (N1, P2) are modulated by the stimulus concentration, whereas the late positive components (P3‐1, P3‐2) vary depending on the subjective stimulus significance and stimulus probability. It is concluded that the positive component of the OERP, which has been formerly explained by chemical and physical stimulus features, is actually determined by endogenous processes.
Mixture analysis of smooth pursuit eye movements in schizophrenia
Authors: ROSS DAVID E. , OCHS ALFRED L. , PANDURANGI ANAND K. , THACKER LEROY R. , KENDLER KENNETH S.
Published: February 2007

The goal of this study was to replicate and extend previous findings indicating that the eye movement data of schizophrenic patients is best represented by the mixture of two groups, one of which has distinctly poor performance. Forty‐nine schizophrenic patients and 32 normal controls had their smooth pursuit eye movements quantified by calculating the root mean square (RMS) deviation between the target and eye waveforms. Based on the finding of mixture in the distribution of RMS error, the patients were divided in to low (better tracking) and high (worse tracking) RMS error subgroups. The high RMS error patient had abnormally decreased gain. Both patient subgroups had abnormally increased frequency of catch‐up saccades and increased phase lag. Distinguishing between these two subgroups may be useful in clarifying the pathophysiology of abnormal pursuit and its relationship to heterogeneity in schizophrenia.
Social support and hostility interact to influence clinic, work, and home blood pressure in Black and White men and women
Authors: BROWNLEY KIMBERLY A. , LIGHT KATHLEEN C. , ANDERSON NORMAN B.
Published: February 2007

The effects of hostility and social support support on clinic, work, and home systolic (SBP) and diastolic (DBP) blood pressures were evaluated in 129 healthy adults. High hostility was related to higher SBP and DBP in Whites; low hostility was related to higher SBP and DBP in Blacks. These relationships were significant for men at home and at work and for women at screening. The relationship between low hostility and higher BP in Blacks was largely due to Black men who reported low hostility plus high anger‐in (suggesting suppressed hostility). In contrast, high hostile Black men with high tangible support tended to exhibit lower BP than all other Black men. In White women, high belonging support was related to lower BP, independent of hostility, and low tangible support plus high hostility was related to higher clinic BP. In high hostile subjects, regardless of ethnicity or gender, high appraisal support was related to lower overall BP. These data suggest that the adverse BP effects of hostility and the beneficial effects of social support interact in a complex manner, reflecting contextual, ethnic, and gender specificities.
Pupillary responses index cognitive resource limitations
Authors: GRANHOLM ERIC , ASARNOW ROBERT F. , SARKIN ANDREW J. , DYKES KAREN L.
Published: February 2007

Cognitive task‐evoked pupillary responses reliably index information‐processing loads. However, previous studies have reported inconsistent findings regarding the nature of the pupillary response when processing demands approach or exceed available processing resources. This condition was examined in 22 normal undergraduates by using pupillometric recordings during a digit span recall task, with 5 (low load), 9 (moderate load), and 13 (excessive load) digits per string. Pupillary responses increased systematically with increased processing load (to‐be‐recalled digits) until the limit of available resources (memory capacity of 7 ± 2 digits), when they reached asymptote and then declined with resource overload (>9 digits). These findings suggest that pupillary responses increase systematically with increased processing demands that are below resource limits, change little during active processing at or near resource limits, and begin to decline when processing demands exceed available resources.