bluuebunny/crossref_metadata_2025 huggingface dataset:
Serotonergic Genes and Suicidality
Authors: Du Lisheng , Faludi Gabor , Palkovits Miklos , Bakish David , Hrdina Pavel D.
Published: April 2003

Summary: Several lines of evidence indicate that abnormalities in the functioning of the central serotonergic system are involved in the pathogenesis of depressive illness and suicidal behavior. Studies have shown that the number of brain and platelet serotonin transporter binding sites are reduced in patients with depression and in suicide victims, and that the density of 5-HT2Areceptors is increased in brain regions of depressed in suicide victims and in platelets of depressed suicidal patients. Genes that code for proteins, such as tryptophan hydroxylase, 5-HT transporter, and 5-HT2Areceptor, involved in regulating serotonergic neurotransmission, have thus been major candidate genes for association studies of suicide and suicidal behavior. Recent studies by our group and by others have shown that genetic variations in the serotonin-system-related genes might be associated with suicidal ideation and completed suicide. We have shown that the 102 C allele in 5-HT2Areceptor gene was significantly associated with suicidal ideation (χ2= 8.5, p < .005) in depressed patients. Patients with a 102 C/C genotype had a significantly higher mean HAMD item #3 score (indication of suicidal ideation) than T/C or T/T genotype patients. Our results suggest that the 102T/C polymorphism in 5-HT2Areceptor gene is primarily associated with suicidal ideation in patients with major depression and not with depression itself. We also found that the 5-HT transporter gene S/L polymorphism was significantly associated with completed suicide. The frequency of the L/L genotype in depressed suicide victims was almost double of that found in control group (48.6% vs. 26.2%). The odds ratio for the L allele was 2.1 (95% CI 1.2-3.7). The association between polymorphism in serotonergic genes and suicidality supports the hypothesis that genetic factors can modulate suicide risk by influencing serotonergic activity.
What Can Psychiatric Genetics Offer Suicidology?
Authors: McGuffin Peter , Marušič Andrej , Farmer Anne
Published: April 2003

Summary: There is good evidence from recent studies that depression is familial, and that a substantial proportion of the variation in liability is explained by genes. Suicidal behavior, including completed suicide, also seems to cluster in families. First-degree relatives of individuals who have committed suicide (included dizygotic twins) have more than twice the risk of the general population. For identical co-twins of suicides, the relative risk increases to about 11. Applying a simple structural equation model to the published data suggests a heritability for completed suicide of about 43% (95% confidence intervals 25-60). It is not known at present whether the genes predisposing to suicide are identical with those predisposing to affective disorder, but since only about half of those committing suicide have a diagnosis of depression, it seems probable that the overlap is incomplete. The mode of inheritance of suicidal behavior is almost certain to be complex, involving many genes. There have already been some initial studies of allelic association with polymorphisms in candidate genes such as those involved in serotonergic transmission. Further progress is likely to come from candidate gene and linkage disequilibrium studies that are capable of detecting multiple genes of small effect.
Bereavement after Suicide—How Far Have We Come and Where Do We Go from Here?
Authors: Clark Sheila
Published: April 2003

Summary: This paper identifies major issues faced by the bereaved, the community, and the helping professions after a suicide. Some significant milestones in knowledge and service provision that have been achieved so far are discussed. It considers how past research in the fields of suicide postvention and general bereavement have developed new variables and frameworks with which to find a way forward in understanding this neglected field. The new standards of care and public policy are described that are anticipated in the light of these insights.
Methodological Issues in Community Surveys of Suicide Ideators and Attempters
Authors: Burless Cornelia , De Leo Diego
Published: April 2003

Summary: There have been quite a number of community studies in recent years, with surveys being conducted among the general population, in schools, and among the elderly. While all of these studies have greatly contributed to our understanding of suicidal behavior, because of different approaches toward methodology and definitions, they also have some limitations. These limitations spring mainly from the fact that definitions of suicidal ideation and behavior vary widely across studies, which makes comparisons between studies unreliable. The different utilization of methodology is another problem that can impact the comparability of the community studies.
Suicidal Behavior in Patients with Adjustment Disorders
Authors: Kryzhanovskaya Ludmila , Canterbury Randolph
Published: April 2003

Summary: This retrospective study characterizes the suicidal behavior in 119 patients with Axis I adjustment disorders as assessed by psychiatrists at the University of Virginia Hospital. Results indicated that 72 patients (60.5%) had documented suicide attempts in the past, 96% had been suicidal during their admission to the hospital, and 50% had attempted suicide before their hospitalization. The most commonly used method of suicide attempts was overdosing. Of the sample group with suicide attempts in the past, 67% had Axis II diagnoses of borderline personality disorder and antisocial personality disorder. Adjustment disorder diagnosis in patients with the suicide attempts was associated with a high level of suicidality at admission, involuntary hospitalization and substance-abuse disorders. Axis II diagnoses in patients with adjustment disorders constituted risk factors for further suicidal behavior. Additional future prospective studies with reliability checks on diagnosis of adjustment disorders and suicidal behavior are needed.
Sex Differences in Suicidal Ideation in a Community Sample from China
Authors: He Zhao Xiong , Lester David
Published: April 2003

Summary: In a large sample of over 4,000 Chinese residents in the Wuling and Sino-Vietnamese border regions of China, females had a higher incidence of ever wishing that they were dead. This sex difference was found regardless of marital status, age, and occupation.
The Media and Suicide: A Cautionary View
Authors: Goldney Robert D.
Published: April 2003

Summary: There is now unequivocal statistical evidence of an association between some media portrayals of suicide and further subsequent suicide. However, it is a weak association, and it is probably of far less importance than our need to address basic principles of good mental health management. Rather than prescribe to the media how to report suicide, its potentially positive effects should be addressed.
Suicide on the Indian Subcontinent
Authors: Khan Murad M.
Published: April 2003

Summary: The Indian subcontinent comprises eight countries (India, Pakistan, Bangladesh, Nepal, Sri Lanka, Afghanistan, Bhutan, and the Maldives) and a collective population of more than 1.3 billion people. 10% of the world's suicides (more than 100,000 people) take place in just three of these countries, viz. India, Sri Lanka, and Pakistan. There is very little information on suicides from the other four countries. Some differences from suicides in Western countries include the high use of organophosphate insecticides, larger numbers of married women, fewer elderly subjects, and interpersonal relationship problems and life events as important causative factors. There is need for more and better information regarding suicide in the countries of the Indian subcontinent. In particular, studies must address culture-specific risk factors associated with suicide in these countries. The prevention of this important public health problem in an area of the world with myriad socio-economic problems, meager resources, and stigmatization of mental illness poses a formidable challenge to mental health professionals, policy makers, and governments of these countries.
Evidence-Based Prevention Strategies of Suicide Behavior in the World: Implications for Slovenia
Authors: Henderson Claire , Dazzan Paola , Dernovsek Mojca , Tavcar Rok , Brecelj Marija
Published: April 2003

Abstract: In this review we consider how Slovenia could consider tackling its high rate of suicide (overall 29 per 100,000, 46 in males, 13 in females). First, we consider the evidence for risk factors that may contribute to Slovenia's high rate of suicide. Second, we describe the interventions to try to reduce the impact of these factors and the evidence for such interventions. We categorize interventions in terms of their operation at either the population level or that of high-risk groups. However, it should be borne in mind that settings often assumed to provide access to population groups, such as general practice and schools, do not reach some people who are likely to be at high risk; for example those who have dropped out of school or who have been excluded from a GP's list. We focus particularly on those for high-risk groups, as a number of East-European countries with high suicide rates such as Slovenia, Hungary, and the Baltic republics are currently considering a shift toward more community-based mental health services. The provision of community mental health services in Slovenia would provide an opportunity to study their impact on the suicide rate. However, we conclude that their development should be accompanied by other initiatives operating at population levels. This multilevel approach acknowledges the complexity of the etiology of suicide, the impossibility of reaching all those at risk through services and the lack of strong evidence for any one intervention.
Gradients of Facial EMG and Cardiac Activity During Emotional Stimulation
Authors: Ritz Thomas , Dahme Bernhard , Claussen Christiane
Published: April 2003

Abstract We investigated the effects of a serial presentation of short emotional stimuli on facial EMG, mood and autonomic functioning including total respiratory resistance (TRR). Twenty asthmatic and 20 nonasthmatic subjects viewed series of happy and depressing pictures and Velten statements. Each series consisted of nine affectively homogeneous stimuli plus one neutral stimulus. During prestimulus, presentation and imagination intervals of each stimulus presentation, heart period (HP) and EMG activity over corrugator supercilii, orbicularis oculi and zygomaticus major muscle sites were recorded. Each series was followed by 1 min measurements of TRR, HP, respiratory sinus arrhythmia, ventilation, and mood. Each stimulus was rated with respect to pleasure and arousal. Successive increases of corrugator EMG were observed throughout the series of depressing and happy stimuli. These gradients were comparable for prestimulus, presentation or imagination intervals, thus yielding no evidence for response habituation or sensitization. Other muscle sites showed only negligible EMG gradients, while HP revealed successive shortening over each stimulus series. Marginal evidence was found to support the suggestion that successive corrugator increases affected mood and stimulus evaluations. Subjects with significant positive corrugator EMG gradients throughout depressing pictures revealed significantly lower TRR following the stimulus series. The observed changes in HP and TRR are compatible with an economical model of autonomic-somatic coupling.
The Influence of Different Doses of Caffeine on Visual Task Performance
Authors: Ruijter Judith , Lorist Monicque M. , Snel Jan
Published: April 2003

Abstract In this study the influence of caffeine as an energy-increasing substance on visual information processing was examined. Subjects were presented with a dual-task consisting of two choice reaction time tasks. In addition, one of the tasks was presented at two levels of difficulty, influencing the decision-making process. Doses of 1.0, 3.0, and 7.5 mg/kg body weight caffeine and 3.0 mg/kg body weight lactose were administered (within-subjects design). The effect of caffeine was expected to be observable in terms of improved performance on measures like reaction time and type and number of errors, as well as in components of the event-related brain potential (ERP). The highest caffeine dose shortened reaction times on both the primary and the secondary task as compared to placebo. Overall there was a linear decline in reaction times on both tasks with increasing caffeine dose. As measured from ERP results, there was an increasing P3 amplitude as caffeine dose increased, indicating that the quantity of information processed was larger under caffeine. There was, however, no evidence of extra energy in terms of more hits and fewer misses or false alarms. Moreover, subjects reported no doserelated differences in amount of effort needed to perform the dual-task. It is concluded that the effect of caffeine, which is supposed to have its impact on both the input and the output stages of information processing, was evident in the output stage in the form of shortened reaction times. However, no effect of caffeine could be observed at the input stage, probably due to a data limited process.
Electrodermal Responsiveness and Negative Symptoms in Brain Injured Patients
Authors: Andersson S. , Finset A.
Published: April 2003

Abstract Electrodermal non-responsiveness has been associated with negative symptoms, especially among schizophrenic patients. The aim of this study was to examine how electrodermal non-response, defined as failure to elicit a skin conductance orienting response to a neutral auditory stimulus, was related to negative symptoms in patients with acquired brain injury. Sixty-four brain injured patients were assessed for apathy, lack of initiative, and emotional indifference. We found that EDA non-responders displayed significantly higher scores on rating scales used to assess apathy and related negative symptoms compared to EDA responders. No such differences were found regarding depressed mood/emotional distress or vegetative symptoms of depression. This difference could not be attributed to neurological etiology nor to localization of lesion. These findings, resembling psychophysiological findings in schizophrenia, indicate that EDA non-response is associated with apathy and related negative symptoms also in brain injured patients. This may also enable a better differentiation between negative symptoms of organic origin and emotional changes related to psychogenic factors after acquired brain damage.
Relation of Accelerometer and EMG Recordings for the Measurement of Upper Extremity Movement
Authors: Keil Andreas , Elbert Thomas , Taub Edward
Published: April 2003

Abstract In order to determine the value of accelerometry as a measure of real world outcome when a subject is outside the laboratory, accelerometer recordings from the wrist were compared with simultaneous electromyogram (EMG) recordings from the lower and upper arm. Accelerometer and EMG signals were recorded simultaneously by the “Kölner Vitaport System,” an ambulatory device. Six male subjects performed standardized tasks as well as activities of daily life (ADL). Low correlations between accelerometer counts and integrated EMG were found in the standardized tasks, whereas there were considerably higher correlations for ADL. However, there was a strong relation between several parameters derived from EMG and accelerometer recordings. The two techniques appear to measure different aspects of movement and may be complementary.
Covariation of Phasic Cardiovascular and Cortical Responses
Authors: van der Veen F.M. , Mulder L.J.M. , Mulder G.
Published: April 2003

Abstract Effects of maintaining an alert state on event-related brain potentials (ERPs) and evoked cardiovascular responses were examined in an auditory detection task. Subjects were instructed to detect a possible difference in frequency between two successively presented tones in 5 s periods. Two types of trials were compared. In the first no tones were presented and subjects had to maintain an alert state for the full five seconds (uninterrupted trials). In the second type the alert state was interrupted by the presentation of visual stimuli which were presented in the second half of the 5 s period (interrupted trials). Both types of trial elicited ERPs with a negative shift consisting of a frontal and a parietal part. Uninterrupted trials elicited a stronger and longer lasting negative shift. This difference was maximal at parietal sites. The stronger negative shift was accompanied by a stronger deceleration in the heart rate response, which started at about the same time as the cortical effect but lasted somewhat longer. Furthermore, uninterrupted trials evoked a stronger decrease in the blood pressure response. This effect showed the expected delay when compared to the effect on heart rate (HR). The cardiovascular data confirmed the hypotheses concerning effects of maintaining an alert state, but the cortical data partly contradicted them. Altogether, the current findings do not contradict an active network involved in alertness, but they do not confirm the expected stronger involvement of the right hemisphere and involvement of prefrontal areas in this function.
Effects of the Common Cold on Subjective Alertness, Reaction Time, and Eye Movements
Authors: Smith Andrew , Rich Neil , Sturgess Wendy , Brice Carolyn , Collison Claire , Bailey Jayne , Wilson Sue , Nutt David
Published: April 2003

Abstract The present study examined whether volunteers with common colds showed impairments in objective and subjective indicators of alertness. All the volunteers (N = 81) were tested when healthy to provide baseline data for mood, simple and choice reaction time tasks, and an anti-saccadic eye movement task. When subjects developed a cold (N = 17) they returned to the laboratory and repeated the procedure. Volunteers (N = 64) who remained healthy over a 10-week period were recalled as controls. The results showed that those with colds felt significantly less alert and had significantly slower simple and choice reaction times and eye movements. This extends earlier research and shows that electrophysiological measures may also be of use in assessing the behavioral changes induced by upper respiratory tract illnesses.
The Contingent Magnetic Variation in Migraine
Authors: Sartory G. , Gillessen V. , Grotemeyer K. H. , Elbert T.
Published: April 2003

Abstract Migraine is characterized by an increased contingent negative variation. Separate comparisons of the early and late component showed that it was the former rather than the latter that was elevated. The function and localization of the early component are as yet poorly understood. The magneto-encephalogram was recorded in 16 patients with migraine and 17 healthy control subjects during a forewarned reaction time task. Neuromagnetic data were recorded with a 37-channel neuromagnetometer with the sensors being placed above the left hemisphere contralaterally to the side of the acoustic stimulation and the motor reaction. Subjects responded to the second of two low intensity sound stimuli that were administered with an interval of 4.5 s. Migraine patients exhibited a significantly higher amplitude of the early component of the contingent magnetic variation (CMV) than controls. Groups did not differ with regard to the amplitude of the late component. Modeling the sources with a single moving equivalent current dipole (ECD) provided a high goodness of fit for the M100 (magnetic N1) in both groups and for the early component of the CMV in migraineurs but not controls. The activity of the early component was centered medially with respect to the M100-ECDs and more laterally so in migraine patients than in controls.
24-h Assessment of Tremor Activity and Posture in Parkinson's Disease by Multi-Channel Accelerometry
Authors: Smeja M. , Foerster F. , Fuchs G. , Emmans D. , Hornig A. , Fahrenberg J.
Published: April 2003

Abstract This study describes a new method, based on accelerometry, which quantifies tremor activity and posture continuously. A total of 25 right-handed patients with Parkinson's disease were recorded in a rest condition and in a postural tremor test, and during 24-h ambulatory monitoring. The tremor parameters, such as amplitude, frequency, and occurrence (percent of time), were derived by joint amplitude-frequency analysis. The DC components of multi-channel accelerometry allowed the detection of posture. A repeated measurement MANOVA was used to test the effects of posture and night-day differences in tremor activity. Further issues included consistencies of amplitude measurements across hands, between tasks, and between segments of recordings. Findings indicated an increase between resting tremor and postural tremor in the three tremor parameters, an increase under distraction, and enhanced activity in sitting compared to standing/walking. The best predictions of daytime monitoring measures, based on resting measures, were made for left hand tremor. This methodology is suitable for the detection of diurnal changes in tremor activity, especially amplitude changes, and for the psychophysiological investigation of enhanced tremor caused by task demands and emotional reactions.
Smoothing Facilitates the Detection of Coupled Responses in Psychophysiological Time Series
Authors: Kettunen Joni , Ravaja Niklas , Keltikangas-Järvinen Liisa
Published: April 2003

Abstract We examined the use of smoothing to enhance the detection of response coupling from the activity of different response systems. Three different types of moving average smoothers were applied to both simulated interbeat interval (IBI) and electrodermal activity (EDA) time series and to empirical IBI, EDA, and facial electromyography time series. The results indicated that progressive smoothing increased the efficiency of the detection of response coupling but did not increase the probability of Type I error. The power of the smoothing methods depended on the response characteristics. The benefits and use of the smoothing methods to extract information from psychophysiological time series are discussed.
ECG Changes, Emotional Arousal, and Subjective State
Authors: Myrtek M. , Frölich E. , Fichtler A. , Brügner G.
Published: April 2003

Abstract Laboratory studies with CHD patients suggest an adverse influence of emotional/mental arousal on myocardial ischaemia or ventricular premature contractions (VPCs). However, it is controversial whether such studies can be generalized to everyday life. In addition, existing ambulatory monitoring studies have shortcomings because emotional arousal is entirely based on subjective reports. The hypothesis of the present study is that during ischaemic episodes or VPCs “objective emotional/mental arousal” will be more pronounced than during comparable episodes without these events. Objective emotional/mental arousal was indicated by a special ambulatory monitoring method which was based on the online analysis of heart rate and physical activity, resulting in the so-called emotional or non-metabolic heart rate. Moreover, the method allowed for ratings of anginal pain. In 223 CHD patients the associations between ischaemia, VPCs, objective emotional/mental arousal, and anginal pain were investigated. Forty-nine patients revealed ischaemic episodes and 115 patients VPCs. Emotional/mental arousal was higher during ischaemic episodes as compared to control minutes whereas minutes with VPCs showed no difference. No differences between ischaemic episodes or VPCs and the respective control minutes were observed for anginal pain. Objective emotional/mental arousal was associated in this study with ischaemia but not with arrhythmia, thus partly confirming the hypothesis stated. Because anginal pain was not related to objective cardiac events, detection of CHD has to rely on medical examinations.
Posterior and Anterior Contribution of Hand-Movement Preparation to Late CNV
Authors: Verleger Rolf , Wauschkuhn Bernd , van der Lubbe Rob , Jaśkowski Piotr , Trillenberg Peter
Published: April 2003

Abstract The late part of the Contingent Negative Variation (CNV) is assumed to be a composite potential, reflecting both movement preparation and several other processes. To assess the contribution of hand-motor preparation to overall CNV, three S1-S2 experiments were performed. Replicating earlier results that have been interpreted as demonstrating hand-motor preparation, experiment 1 showed that CNV gets larger centro-parietally under speed instruction. Experiments 2 and 3 compared preparation for hand responses (key-press) to preparation for ocular responses (saccades) varying the effector system either between blocks (exp. 2) or between trials (exp. 3) and also comparing these preparation situations to no preparation (exp. 3). Hand-motor preparation was reflected in CNV getting larger fronto-centrally, with this topography being significantly different from the effect in experiment 1. Thus, two different kinds of motor preparation appear to be reflected by CNV. One kind may consist of assembling and maintaining the stimulus-response links appropriate to the expected S2 patterns, the other is for activating the hand-motor area. These two motor contributions to CNV might reflect the two aspects of the parieto-frontal motor system.
Investigation of Threat-Related Attentional Bias in Anxious Children Using the Startle Eyeblink Modification Paradigm
Authors: Waters Allison M. , Lipp Ottmar V. , Cobham Vanessa E.
Published: April 2003

Abstract We used the startle eyeblink modification paradigm to investigate whether clinically anxious children, like high trait-anxious adults, display a bias in favour of threat words compared to neutral words. The present study included 16 clinically anxious children whose diagnostic status was determined using the parent version of a semistructured diagnostic interview as part of a larger childhood anxiety study. The children were presented with threat and neutral words for 6 s each. A startle-eliciting auditory stimulus - a 100 dBA burst of white noise of 50 ms duration - was presented during the words at lead intervals of 60, 120, 240, or 3500 ms and during intertrial intervals. The overall pattern of startle eyeblink modification indicated inhibition at the 120 and 240 ms lead intervals and facilitation at the 3500 ms lead interval. Startle-latency shortening during threat words at the 60 ms lead interval was larger than at other intervals, whereas there was no difference during neutral words. This result reflects an anxiety-related bias in favour of threat words occurring at a very early - and possibly preattentive stage - of information processing.
Spectral and Topographic Microstructure of Brain Alpha Activity During Drowsiness at Sleep Onset and REM Sleep
Authors: Cantero José Luis , Atienza Mercedes
Published: April 2003

Abstract High-resolution frequency methods were used to describe the spectral and topographic microstructure of human spontaneous alpha activity in the drowsiness (DR) period at sleep onset and during REM sleep. Electroencephalographic (EEG), electrooculographic (EOG), and electromyographic (EMG) measurements were obtained during sleep in 10 healthy volunteer subjects. Spectral microstructure of alpha activity during DR showed a significant maximum power with respect to REM-alpha bursts for the components in the 9.7-10.9 Hz range, whereas REM-alpha bursts reached their maximum statistical differentiation from the sleep onset alpha activity at the components between 7.8 and 8.6 Hz. Furthermore, the maximum energy over occipital regions appeared in a different spectral component in each brain activation state, namely, 10.1 Hz in drowsiness and 8.6 Hz in REM sleep. These results provide quantitative information for differentiating the drowsiness alpha activity and REM-alpha by studying their microstructural properties. On the other hand, these data suggest that the spectral microstructure of alpha activity during sleep onset and REM sleep could be a useful index to implement in automatic classification algorithms in order to improve the differentiation between the two brain states.
N200 in the Eriksen-Task: Inhibitory Executive Processes?
Authors: Heil Martin , Osman Allen , Wiegelmann Juliane , Rolke Bettina , Hennighausen Erwin
Published: April 2003

Abstract Event-related potentials were recorded (N = 18) in a hybrid go/no-go Eriksen flanker task to study the neural correlates of response inhibition. Three letters were assigned to either a left-hand, a right-hand, or a no-go response. These three letters appeared either as targets signaling the assigned response or as flankers surrounding the target. The lateralized readiness potentials revealed erroneous cortical response priming on go trials, in which the target and flankers were assigned to different hands, as well as on no-go trials, in which the flankers primed one of the two hands. Exactly these two conditions were accompanied by a fronto-central amplitude modulation of the N200, suggesting that this ERP component may reflect inhibitory executive functions. The data replicate and extend recent studies by Kopp, Rist, and Mattler (1996) and Kopp, Mattler, Goertz, and Rist (1996) .
Event-Related Brain Potentials and Central Executive Function: Further Evidence for Baddeley's Model
Authors: Kiss Ivan , Pazderka-Robinson Hannah , Floden Darlene
Published: April 2003

Baddeley's influential model of working memory postulates a unitary central executive that allocates mental resources to several distinct short-term buffers. Subjects viewed individually presented single numerals and were required to maintain memory sets comprised of the most recently represented three stimuli. A clearly discernible visual event-related potentials (ERP) component emerged once the lengths of series of individual numbers exceeded memory set size and revision of working memory contents was required. An ERP correlate of working memory revision also emerged upon updating of auditory stimuli. This component was absent when subjects were exposed to the same series of stimuli in a standard “oddball” target detection situation. ERPs elicited when subjects were given the opportunity to rehearse without the need to update working memory contents clearly differed in latency from ERPs seen during updating. These findings provide support for previous studies suggesting a specific ERP correlate of central executive processes in working memory and are consistent with Baddeley's model.
Visual Spatial Attention in Migraine Sufferers in Postictal and Interictal Phases: An Event-Related Potential Study
Authors: de Koning D.H. , Woestenburg J.C. , Elton M.
Published: April 2003

Migraineurs with and without aura (MWAs and MWOAs) as well as controls were measured twice with an interval of 7 days. The first session of recordings and tests for migraineurs was held about 7 hours after a migraine attack. We hypothesized that electrophysiological changes in the posterior cerebral cortex related to visual spatial attention are influenced by the level of arousal in migraineurs with aura, and that this varies over the course of time. ERPs related to the active visual attention task manifested significant differences between controls and both types of migraine sufferers for the N200, suggesting a common pathophysiological mechanism for migraineurs. Furthermore, migraineurs without aura (MWOAs) showed a significant enhancement for the N200 at the second session, indicating the relevance of time of measurement within migraine studies. Finally, migraineurs with aura (MWAs) showed significantly enhanced P240 and P300 components at central and parietal cortical sites compared to MWOAs and controls, which seemed to be maintained over both sessions and could be indicative of increased noradrenergic activity in MWAs.
Real-Life Stress and Opioid-Mediated Analgesia in Novice Parachute Jumpers
Authors: Janssen Sabine A. , Arntz Arnoud
Published: April 2003

Abstract It was investigated whether a stress-induced analgesia could be demonstrated in human subjects (N = 24) performing a first-time parachute jump. Sensitivity for electrical stimulation and pressure pain was measured at several moments before and after the jump. The opioid antagonist naloxone or saline placebo was administered immediately after the jump to examine possible opioid-mediated effects. After the jump, the placebo group showed a lower pain sensitivity than the naloxone group, with the latter returning to pretest levels, consistent with an opioid-mediated analgesia. Although analgesic effects appear to have been initiated prior to the jump, plasma β-endorphin showed a sudden large increase immediately after the jump. This increase correlated with reports of anxiety and loss of control during the jump, and was associated with reduced pain sensitivity. Despite several limitations, this study suggests that the real-life stress of a parachute jump may attenuate pain through endogenous opioid release.
In Search of the “Duchenne Smile”: Evidence from Eye Movements
Authors: Williams Leanne M. , Senior Carl , David Anthony S. , Loughland Carmel M. , Gordon Evian
Published: April 2003

Abstract Duchenne de Boulogne (1862/1990) observed that authentic smiles are distinguished from posed smiles by contractions of the orbicularis oculi muscle that surrounds the eye. Hager and Ekman (1985) subsequently reported that the “Duchenne smile” is discriminated specifically by contractions at the outer corners of the eyes (“crows feet” wrinkles). Little is known of the visuo-cognitive strategies that underpin perception of the Duchenne smile. We examined ocular dynamics (pattern of eye fixations) as an overt and accessible index of these strategies (Stark & Ellis, 1981). The spatio-temporal fixation indices were number and duration of foveal fixations to the crows feet area relative to the total face area. In line with predictions, subjects (n = 58) made proportionately more fixations of longer duration to the crows feet area for smiling, compared to negative (sad) and baseline (neutral) control expressions. It is suggested that a “hardwired” response may be involved in reference to this particular anatomical marker of the genuine smile. Humans may have evolved to distinguish the Duchenne smile because of its important communicative role.
Processing Spatial and Temporal Discontinuities: Electrophysiological Indicators
Authors: Schlaghecken Friederike , Meinecke Cristina , Schröger Erich
Published: April 2003

Abstract In a series of four experiments measuring behavioral performance and event-related brain potentials (“ERPs”) in a texture segmentation task, we investigated whether there is evidence that texture stimuli containing a local discontinuity (“D-textures”) are conceptually different from homogeneous stimuli (“H-textures”). Stimuli were presented in an oddball design, with relative frequency of D-textures and H-textures being varied between experiments. It was found that these stimuli are not interchangeable in an oddball situation, as rare D-textures in a context of frequent H-textures give rise to the typical N2b-P3b effects, whereas rare H-textures in a context of frequent D-textures do not. This asymmetry arose because D-textures always elicited enlarged P3b components regardless of their relative frequency. It was concluded that the spatial discontinuity in D-textures adds a feature of “targetness” to these stimuli. Moreover, it was found that a posterior negative-going shift in the N2b latency range (“pN2b”) was mainly modulated by visual stimulus features. This result confirms and extends earlier findings demonstrating the sensitivity of the posterior N2b to physical stimulus characteristics.
Blink Startle Modulation During Anticipation of Pleasant and Unpleasant Stimuli
Authors: Lipp Ottmar V. , Cox Darrin , Siddle David A.T.
Published: April 2003

Abstract The present research investigated blink startle modulation during the anticipation of pleasant, unpleasant, or neutral pictures. In Experiment 1 (N = 18), participants were presented with three different tone-picture pairings. Tones differed in pitch and were followed by pleasant, neutral or unpleasant pictures. Acoustic blink reflexes were elicited during some tones and during stimulus free intervals. Blink facilitation during tones that preceded pleasant and unpleasant pictures was larger than during the tone that preceded neutral pictures. Experiment 2 (N = 10) assessed whether this difference was due to a difference in the presentation frequency of the three conditions. No difference in blink facilitation between the conditions was found when pictures of flowers and mushrooms replaced the pleasant and unpleasant pictures, indicating that picture content was instrumental in causing the differential blink facilitation in Experiment 1. The results from Experiment 1 seem to indicate that startle modulation during the anticipation of pictorial material reflects the interest in or the arousal associated with the pictures rather than picture valence.
Assessing the Effects of Attention and Emotion on Startle Eyeblink Modulation
Authors: Lipp Ottmar V. , Neumann David L. , Siddle David A.T. , Dall Patricia J.
Published: April 2003

Abstract Two experiments were conducted to assess simultaneously the effects of attentional and emotional processes on startle eyeblink modulation. In each experiment, participants were presented with a pleasant and an unpleasant picture. Half the participants were asked to attend to the pleasant picture and to ignore the unpleasant picture, whereas the reverse was the case for the other participants. Startle probes were presented at 3500 and 4500 ms after stimulus onset in Experiment 1 and at 250, 750, and 4450 ms after stimulus onset and 950 ms after stimulus offset in Experiment 2. Attentional processing affected startle eyeblink modulation and electrodermal responses in both experiments. However, effects of picture valence on startle eyeblink modulation were found only in Experiment 2. The results confirm the utility of startle eyeblink modulation as an index of attentional and emotional processing. They also illustrate that procedural characteristics, such as the nature of the lead intervals and how attention and emotion are operationalized, can determine whether emotional or attentional processes will be reflected in startle eyeblink.
Electroencephalography Activity Associated with Driver Fatigue: Implications for a Fatigue Countermeasure Device
Authors: Lal Saroj K.L. , Craig Ashley
Published: April 2003

Abstract This paper reviews the association between electroencephalography (EEG) activity and driver fatigue. The current literature shows substantial evidence of changes in brain wave activity, such as simultaneous changes in slow-wave activity (e.g., delta and theta activity) as well as alpha activity during driver fatigue. It is apparent from the literature review that EEG is a promising neurophysiological indicator of driver fatigue and has the potential to be incorporated into the development of a fatigue countermeasure device. The findings from this review are discussed in the light of directions for future fatigue research studies.
Covariation and Temporal Stability of Peripheral and Brachial Blood Pressure Responses to Mental and Static Stress
Authors: Hinz Andreas , Seibt Reingard , Scheuch Klaus
Published: April 2003

Abstract Peripheral blood pressure measurement (Finapres technique) is a promising development in activation research. This paper tests and compares the temporal stability and covariation of peripheral and brachial blood pressure responses. Forty healthy subjects were tested four times at intervals of 1 day, 1 week, and 1 month. The tasks employed were two mental tasks (mental arithmetic and a Color Word Test) and a static (fingergrip) task. Recorded physiological parameters were peripheral and brachial systolic (SBP) and diastolic blood pressure (DBP). Mean peripheral SBP was about 20 mmHg higher than brachial SBP, but the difference between the DBP measures was negligible. Correlations between peripheral and corresponding brachial BP resting levels were low, with coefficients below 0.30. The correlations between peripheral and brachial SBP and DBP were higher for reactivity (change) scores (0.46-0.82) than for resting scores. Several types of inter- and intraindividual covariation were calculated to provide a deeper understanding of the relationship between the physiological parameters with respect to their dynamics. Temporal stability of peripheral BP level scores was lower (0.37-0.57) than for brachial BP (0.59-0.77), but the stability of the change scores was similar for both BP techniques. The results show that it is important to distinguish between several aspects of the mutual relationship between peripheral and brachial BP measures. Peripheral BP measurements are not suited to assess the BP level of a subject, but they are very useful to assess cardiovascular reactivity.
An Event-Related fMRI Study of Visual and Auditory Oddball Tasks
Authors: Kiehl Kent A. , Laurens Kristin R. , Duty Timothy L. , Forster Bruce B. , Liddle Peter F.
Published: April 2003

Abstract Whole brain event-related functional magnetic resonance imaging (fMRI) techniques were employed to elucidate the cerebral sites involved in processing rare target and novel visual stimuli during an oddball discrimination task. The analyses of the hemodynamic response to the visual target stimuli revealed a distributed network of neural sources in anterior and posterior cingulate, inferior and middle frontal gyrus, bilateral parietal lobules, anterior superior temporal gyrus, amygdala, and thalamus. The analyses of the hemodynamic response for the visual novel stimuli revealed an extensive network of neural activations in occipital lobes and posterior temporal lobes, bilateral parietal lobules, and lateral frontal cortex. The hemodynamic response associated with processing target and novel stimuli in the visual modality were also compared with data from an analogous study in the auditory modality ( Kiehl et al., 2001 ). Similar patterns of activation were observed for target and novel stimuli in both modalities, but there were some significant differences. The results support the hypothesis that target detection and novelty processing are associated with neural activation in widespread neural areas, suggesting that the brain seems to adopt a strategy of activating many potentially useful brain regions despite the low probability that these brain regions are necessary for task performance.
Event-Related Potentials, Configural Encoding, and Feature-Based Encoding in Face Recognition
Authors: James Melissa S. , Johnstone Stuart J. , Hayward William G.
Published: April 2003

Abstract The effects of manipulating configural and feature information on the face recognition process were investigated by recording event-related potentials (ERPs) from five electrode sites (Fz, Cz, Pz, T5, T6), while 17 European subjects performed an own-race and other-race face recognition task. A series of upright faces were presented in a study phase, followed by a test phase where subjects indicated whether inverted and upright faces were studied or novel via a button press response. An inversion effect, illustrating the disruption of upright configural information, was reflected in accuracy measures and in greater lateral N2 amplitude to inverted faces, suggesting that structural encoding is harder for inverted faces. An own-race advantage was found, which may reflect the use of configural encoding for the more frequently experienced own-race faces, and feature-based encoding for the less familiar other-race faces, and was reflected in accuracy measures and ERP effects. The midline N2 was larger to configurally encoded faces (i. e., own-race and upright), possibly suggesting configural encoding involves more complex processing than feature-based encoding. An N400-like component was sensitive to feature manipulations, with greater amplitude to other-race than own-race faces and to inverted than upright faces. This effect was interpreted as reflecting increased activation of incompatible representations activated by a feature-based strategy used in processing of other-race and inverted faces. The late positive complex was sensitive to configural manipulation with larger amplitude to other-race than own-race faces, and was interpreted as reflecting the updating of an own-race norm used in face recognition, to incorporate other-race information.
Smoking/Nicotine Affects the Magnitude and Onset of Lateralized Readiness Potentials
Authors: Houlihan Michael E. , Pritchard Walter S. , Guy Thomas D. , Robinson John H.
Published: April 2003

AbstractSmoking/nicotine improves cognitive performance for a variety of tasks. In most cases, reaction time (RT) is generally shorter after smoking/nicotine. While there may be some slight facilitation of stimulus-evaluation processing, most of the RT effects of nicotine appear to take place following the response-selection stage. This study investigated possible effects (in smokers) of smoking/nicotine on response preparation and execution processes using the lateralized readiness potential (LRP). On each trial, a warning stimulus preceded an imperative stimulus by 1.2s. The warning stimulus completely specified the correct response to the imperative stimulus. The study was completed in two morning sessions in which 4 cigarettes were smoked in each session. The nicotine yield of the cigarettes varied between sessions (0.05mg or 1.1mg). Maximum amplitudes of both the stimulus and response-locked LRPs were larger in the 1.1 mg session. For both stimulus- and response-locked LRPs, smoking the 1.1 mg cigarette (but not the 0.05 mg cigarette) shortened onset latency. However, the magnitude of the effect was much larger for the stimulus-locked LRPs, suggesting that response preparation is facilitated by smoking/nicotine to a greater degree than response execution.
Human Event-Related Potentials to Higher-Order Acoustic Spatial Changes
Authors: Ruusuvirta Timo , Hämäläinen Heikki
Published: April 2003

Abstract Human event-related potentials (ERPs) to a tone continuously alternating between its two spatial loci of origin (middle-standards, left-standards), to repetitions of left-standards (oddball-deviants), and to the tones originally representing these repetitions presented alone (alone-deviants) were recorded in free-field conditions. During the recordings (Fz, Cz, Pz, M1, and M2 referenced to nose), the subjects watched a silent movie. Oddball-deviants elicited a spatially diffuse two-peaked deflection of positive polarity. It differed from a deflection elicited by left-standards and commenced earlier than a prominent deflection of negative polarity (N1) elicited by alone-deviants. The results are discussed in the context of the mismatch negativity (MMN) and previous findings of dissociation between spatial and non-spatial information in auditory working memory.