bluuebunny/crossref_metadata_2025 huggingface dataset:
Enacting Democracy
Authors: Saward Michael
Published: December 2004

We do not need more ‘models of democracy’, but we do need a fresh view of democratic theory to take full advantage of deliberative, ecological, cosmopolitan and other innovations of recent years. Approaches such as these can be understood in terms of the devices they deploy – deliberative forums and cross-border referendums, for example, as well as more familiar elections and legislatures. Devices enact democratic principles; indeed, it is argued that principles gain their meaning and force through enactment. Devices can also be reordered in different ways; democrats can construct sequences which enact democracy in particular, desired ways. Pursuing this argument involves adopting a reflexive and procedural perspective, which puts a premium on democracy as sensitive to context, open-ended, productive and adaptable.
Professional Political Consultants: An Operational Definition
Authors: Medvic Stephen K.
Published: December 2004

Although political consultants have increasingly been the subject of scholarly research, there is little agreement as to what a ‘political consultant’ actually is. Early research in the field, and a good deal of contemporary work as well, has provided only vague conceptualisations of the term. Recent quantitative work that attempts to examine the role and impact of consultants in elections suffers from a lack of a common operational definition. After a brief review of the way systematic empirical researchers operationalise ‘professional political consultant,’ I offer a comprehensive definition that can be used in future research on the topic. Without an agreed definition to employ, the study of political consulting will remain idiosyncratic and fragmentary. That, in turn, hampers efforts to provide normative evaluation, and comparative analysis, of the consulting phenomenon.
Transient Spatial Attention Degrades Temporal Resolution
Authors: Yeshurun Yaffa , Levy Liat
Published: December 2004

To better understand the interplay between the temporal and spatial components of visual perception, we studied the effects of transient spatial attention on temporal resolution. Given that spatial attention sharpens spatial resolution, can it also affect temporal resolution? To assess temporal resolution, we measured the two-flash fusion threshold. When two flashes of light are presented successively to the same location, the two-flash fusion threshold is the minimal interval between the flashes at which they are still perceived as two flashes, rather than a single flash. This assessment of temporal resolution was combined with peripheral precuing—a direct manipulation of transient spatial attention. This allowed us to demonstrate, for the first time, that spatial attention can indeed affect temporal resolution. However, in contrast to its effect on spatial resolution, spatial attention degrades temporal resolution. Two attentional mechanisms that could account for both attentional effects—enhanced spatial resolution and reduced temporal resolution—are discussed.
Policy punctuations in the UK: fluctuations and equilibria in central government expenditure since 1951
Authors: John Peter , Margetts Helen
Published: December 2004

Jones and Baumgartner's punctuated equilibrium model of agenda change has reinvigorated decision‐making theory; moreover their US budget project offers a set of techniques to apply to UK data. We replicate the method by plotting percentage budget changes in central government budgets to see whether the distribution is normally distributed as predicted by the incrementalist account or leptokurtic as hypothesized by the punctuated equilibrium model. Taking the period 1951–96, we create 405 data points from budget changes from the National Income Accounts (‘Blue Book’) on agriculture, defence, social security, education, health, housing, industry, law and order and transport, all adjusted using the GDP deflator at factor cost. We find that the budget changes form a leptokurtic distribution. Such a pattern appears in most policy sectors.
Ethics, values and behaviours: comparison of three case studies examining the paucity of leadership in government
Authors: Kakabadse Andrew , Korac‐Kakabadse Nada , Kouzmin Alexander
Published: December 2004

Three societies with similar initiatives for public service re‐configuration and reform – the UK, Canada and Australia – are examined to highlight the many‐faceted issues of public service ethics and the different approaches these governments have taken to re‐building public trust and enhancing public service ethics in times of rapid change. These efforts for re‐building an ethical public service are scrutinized according to four criteria for effectively leading change. Changes of public service values are also analysed as well as their implications for public servants.

Effectively, applied leadership is identified as the pillar of ethical practice – emphasizing the need for quality leadership development through on‐the‐job experience. Although legislation and codification are seen as necessary for building an ethical infrastructure that can help employees out of encountered dilemmas, the way forward is seen as nurturing an environment of trust and vigilance in which ethics are promoted through exemplary behaviour of leaders and employees alike.
European governance and the transfer of ‘new’ environmental policy instruments (NEPIs) in the European Union
Authors: Jordan Andrew , Wurzel Rüdiger , Zito Anthony R. , Brückner Lars
Published: December 2004

This article examines the use of ‘new’ environmental policy instruments (NEPIs), particularly market‐based instruments (for example, eco‐taxes) and voluntary agreements, in the European Union (EU). It focuses on the actor motivation behind the recent increase in the adoption of new and innovative instruments in EU (and member state) environmental policies while also taking account of the external international arena. The article assesses whether new ideas put forward by policy entrepreneurs, such as member governments, EU institutions, expert groups and non‐governmental organizations (NGOs), are the main motivation behind the EU adoption of NEPIs, or whether market and harmonization pressures are the main driving forces. It concentrates on eco‐taxes, voluntary agreements and eco‐labels, using the following three theoretical perspectives: (1) policy learning and transfer/ideational; (2) garbage can; and (3) institutional approaches.
Towards a literacy of fusion: new times, new teaching and learning?
Authors: Millard Elaine
Published: December 2004

This paper seeks to widen discussion about which forms of literacy are most appropriate for the education of children in the twenty‐first century. It outlines the current debate about the changes to children's literacy practices, which are described as being prompted on the one hand by the pervasive influence in society of new technologies, and on the other by the extent of pupils' engagement with popular culture. Using a single example, representative of a number of classroom action research studies devised by the author in which children's own interests were used to motivate writing, she argues that what is required from teachers is a transformative pedagogy. This would allow children's cultural interest to be merged with the school requirements into what is described as aliteracy of fusion. The paper ends with an outline of the aspects of learning to which a teacher working to create such forms of literacy would need to attend.
Interpreting Statistical Evidence by using Imperfect Models: Robust Adjusted Likelihood Functions
Authors: Royall Richard , Tsou Tsung-Shan
Published: December 2004

The strength of statistical evidence is measured by the likelihood ratio. Two key performance properties of this measure are the probability of observing strong misleading evidence and the probability of observing weak evidence. For the likelihood function associated with a parametric statistical model, these probabilities have a simple large sample structure when the model is correct. Here we examine how that structure changes when the model fails. This leads to criteria for determining whether a given likelihood function is robust (continuing to perform satisfactorily when the model fails), and to a simple technique for adjusting both likelihoods and profile likelihoods to make them robust. We prove that the expected information in the robust adjusted likelihood cannot exceed the expected information in the likelihood function from a true model. We note that the robust adjusted likelihood is asymptotically fully efficient when the working model is correct, and we show that in some important examples this efficiency is retained even when the working model fails. In such cases the Bayes posterior probability distribution based on the adjusted likelihood is robust, remaining correct asymptotically even when the model for the observable random variable does not include the true distribution. Finally we note a link to standard frequentist methodology—in large samples the adjusted likelihood functions provide robust likelihood-based confidence intervals.
Diagnostics for Dependence within Time Series Extremes
Authors: Ledford Anthony W. , Tawn Jonathan A.
Published: December 2004

The analysis of extreme values within a stationary time series entails various assumptions concerning its long- and short-range dependence. We present a range of new diagnostic tools for assessing whether these assumptions are appropriate and for identifying structure within extreme events. These tools are based on tail characteristics of joint survivor functions but can be implemented by using existing estimation methods for extremes of univariate independent and identically distributed variables. Our diagnostic aids are illustrated through theoretical examples, simulation studies and by application to rainfall and exchange rate data. On the basis of these diagnostics we can explain characteristics that are found in the observed extreme events of these series and also gain insight into the properties of events that are more extreme than those observed.
On-Line Inference for Hidden Markov Models via Particle Filters
Authors: Fearnhead Paul , Clifford Peter
Published: December 2004

We consider the on-line Bayesian analysis of data by using a hidden Markov model, where inference is tractable conditional on the history of the state of the hidden component. A new particle filter algorithm is introduced and shown to produce promising results when analysing data of this type. The algorithm is similar to the mixture Kalman filter but uses a different resampling algorithm. We prove that this resampling algorithm is computationally efficient and optimal, among unbiased resampling algorithms, in terms of minimizing a squared error loss function. In a practical example, that of estimating break points from well-log data, our new particle filter outperforms two other particle filters, one of which is the mixture Kalman filter, by between one and two orders of magnitude.
Nonviolence Is Who? Gene Sharp and Gandhi
Authors: Weber Thomas
Published: December 2004

There appear to be two approaches to nonviolence. They have been termed “principled,” where emphasis is on human harmony and a moral rejection of violence and coercion, and “pragmatic,” where conflict is seen as normal and the rejection of violence as an effective way of challenging power. Failure to distinguish between the two strands can lead to a diminution in the effectiveness of nonviolent action and can cause confusion among the audience. The acknowledged leading figures representing these approaches are Mahatma Gandhi and Gene Sharp. Sharp was once an idealistic seeker after Gandhi, yet his later work is characterized by hard‐bitten realism. He now champions a “technique approach” to nonviolent action, arguing that it should be used for pragmatic rather than for religious or ethical reasons. Depending on how one looks at it, Sharp either has gone beyond Gandhi, making nonviolence a more practically available method of struggle, or has ditched key elements of Gandhi's philosophy in action in a way that diminishes nonviolence. Perhaps rather than debating the merits of each approach, they can be seen as indicating alternative paths to the traveler who does not want to use violence.
‘Sites of memory’ of the Holocaust: shaping national memory in the education system in Israel
Authors: Resnik Julia
Published: December 2004

Abstract. This article attempts to understand the development of the national memory in Israel and the stress on the Holocaust as the constitutive representation of the national identity in the last decades. In the first three decades of the existence of the state, at a time Israeli society was embedded in an ‘environment of memory’ due to the presence of a big proportion of Holocaust survivors, the subject of the Holocaust was almost neglected in schools. On the other hand, since the 1980s, when the ‘environment of memory’ of the Holocaust started to fade naturally, ‘sites of memories’ of the Holocaust started to blossom in the education system. The national memory is meant to support political and social arrangements in the present; thus, in order to shape national subjects, the education system has to adapt the official memory accordingly. While in the past, the memory of the Holocaust was counterproductive to the formation of the ‘new Jew’, it became an appropriate response to the crisis of the national subjectivity unleashed after the Yom Kippur War.
The psychophysiology of anxiety disorder: Fear memory imagery
Authors: Cuthbert Bruce N. , Lang Peter J. , Strauss Cyd , Drobes David , Patrick Christopher J. , Bradley Margaret M.
Published: December 2004

Psychophysiological response to fear memory imagery was assessed in specific phobia, social anxiety disorder, panic disorder with agoraphobia, post‐traumatic stress disorder (PTSD), and healthy controls. Heart rate, skin conductance, and corrugator muscle were recorded as participants responded to tone cues signaling previously memorized descriptor sentences. Image contents included personal fears, social fears, fears of physical danger, and neutral (low arousal) scenes. Reactions to acoustic startle probes (eyeblink) were assessed during recall imagery and nonsignal periods. Participants were significantly more reactive (in physiology and report of affect) to fear than neutral cues. Panic and PTSD patients were, however, less physiologically responsive than specific phobics and the socially anxious. Panic and PTSD patients also reported the most anxiety and mood symptoms, and were most frequently comorbidly depressed. Overall, physiological reactivity to sentence memory cues was greatest in patients with focal fear of specific objects or events, and reduced in patients characterized by generalized, high negative affect.
Effects of auditory distraction on electrophysiological brain activity and performance in children aged 8–13 years
Authors: Gumenyuk Valentina , Korzyukov Oleg , Alho Kimmo , Escera Carles , Näätänen Risto
Published: December 2004

Distractibility was investigated in three age groups of children (8–9, 10–11, and 12–13 years) with event‐related brain potentials (ERPs) and performance measures in a forced‐choice visual task. Distraction was reflected by increased reaction times (RTs) and decreased performance accuracy in the visual discrimination task following presentation of unexpected novel sounds. The amplitude of the late portion of the P3a elicited by novel sounds was largest for the youngest group and showed a centrally dominant scalp distribution and smallest for the oldest group with a frontal scalp distribution. A frontally dominant late negativity (LN) that was largest in the youngest group followed the P3a. Correlation between the RT increase caused by the distracting novel sounds and the amplitude of the LN elicited by these sounds suggested that the LN is associated with the degree of attention engaged by the distracting sounds.
The error‐related negativity as a state and trait measure: Motivation, personality, and ERPs in response to errors
Authors: Pailing Patricia E. , Segalowitz Sidney J.
Published: December 2004

This study examines changes in the error‐related negativity (ERN/Ne) related to motivational incentives and personality traits. ERPs were gathered while adults completed a four‐choice letter task during four motivational conditions. Monetary incentives for finger and hand accuracy were altered across motivation conditions to either be equal or favor one type of accuracy over the other in a 3:1 ratio. Larger ERN/Ne amplitudes were predicted with increased incentives, with personality moderating this effect. Results were as expected: Individuals higher on conscientiousness displayed smaller motivation‐related changes in the ERN/Ne. Similarly, those low on neuroticism had smaller effects, with the effect of Conscientiousness absent after accounting for Neuroticism. These results emphasize an emotional/evaluative function for the ERN/Ne, and suggest that the ability to selectively invest in error monitoring is moderated by underlying personality.
Syntactic processing with aging: An event‐related potential study
Authors: Kemmer Laura , Coulson Seana , De Ochoa Esmeralda , Kutas Marta
Published: December 2004

To assess age‐related changes in simple syntactic processing with normal aging, event‐related brain potentials (ERPs) elicited by grammatical number violations as individuals read sentences for comprehension were analyzed. Violations were found to elicit a P600 of equal amplitude and latency regardless of an individual's age. Instead, advancing age was associated with a change in the scalp distribution of the P600 effect, being less asymmetric and more frontal (though still with a parietal maximum) in older than younger adults. Our results thus show that the brain's response to simple syntactic violations, unlike those reported for simple binary categorizations and simple semantic violations, is neither slowed nor diminished in amplitude by age. At the same time, the brain's processing of these grammatical number violations did engage at least somewhat different brain regions as a function of age, suggesting a qualitative change rather than any simple quantitative change in speed of processing.
Methylphenidate's effects on paired‐associate learning and event‐related potentials of young adults
Authors: Brumaghim Joan T. , Klorman Rafael
Published: December 2004

The effects of methylphenidate (0.3 mg/kg) on young adults' paired‐associate learning (PAL) of consonant–vowel–consonant (CVC) pairs and concomitant event‐related potentials were assessed. The stimulant elevated mood and heart rate but did not affect PAL performance. For the first CVC, there were amplitude increases with learning for P3b at Pz, P2 at midline sites, and for a negative slow wave at Cz. For the second CVC, P3b and positive slow wave amplitude declined with learning. Increases in P3b amplitude to the first CVC were attributed to increments in stimulus meaningfulness. Decreases in P3b amplitude to the second CVC were interpreted as resulting from fewer disconfirmed expectations of feedback. The negative slow wave following the first CVC was viewed as a contingent negative variation. Methylphenidate increased parietal P3b amplitude for CVC 2, averaged over learning phases.
Jackknife‐based method for measuring LRP onset latency differences
Authors: Miller Jeff , Patterson Tui , Ulrich Rolf
Published: December 2004

A new method based on jackknifing is presented for measuring the difference between two conditions in the onset latencies of the lateralized readiness potential (LRP). The method can be used with both stimulus‐ and response‐locked LRPs, and simulations indicate that it provides accurate estimates of onset latency differences in many common experimental conditions.
Single‐sweep analysis of the theta frequency band during an auditory oddball task
Authors: Yordanova Juliana , Kolev Vasil
Published: December 2004

The P300 component and the oscillatory 4–7 Hz electroencephalographic activity of auditory event‐related brain potentials (ERPs) were assessed to study differences between passive and oddball task conditions. Theta responses from 15 adults were analyzed for single‐sweep amplitude, phase locking, and enhancement against prestimulus activity. ERPs were characterized by enhanced and strongly phase‐locked theta oscillations in the early (0–300 ms) poststimulus epoch, with only the late (300–600 ms) theta responses at Fz and Pz affected by the oddball condition. P300 was strongly associated not only with the concurrent theta oscillations but also with the evoked theta activity preceding P300 (0–300 ms). It was concluded that single theta response parameters can reveal specific functional differences between passive and oddball conditions and that a strong relationship exists between the theta frequency component and the time domain P300 ERP component.
Minding the body
Authors: Kutas Marta , Federmeier Kara D.
Published: December 2004

As we continue to elucidate relationships between neural structures and cognitive functioning in this Decade of the Brain, it is important not to lose sight of the larger context. The brain is but one component of the complex system that is the body. We take in information and interact with the world through our bodies, and our bodies change with—and in some cases change—cognitive and emotional processing. In this introductory paper, we present an overview of a broad range of psychophysiological techniques: electroencephalography, event‐related potentials, magnetoencephalography, positron emission tomography, optical imaging, functional magnetic resonance imaging, electromyograms, eye tracking, pupillometry, cardiovascular measures, and electrodermal activity. These techniques not only differ in their temporal and spatial resolutions but also in the physiological and psychological processes to which they are sensitive. With respect to the system as a whole, these techniques are thus complementary. Combining measures—old and new, central and peripheral—ultimately provides the most inferential power for attacking the questions we hope to answer with all psychophysiological measures in our quest to understand the nature of the relationship between the mind and the body.
Functional neuroanatomical correlates of electrodermal activity: A positron emission tomographic study
Authors: Fredrikson Mats , Furmark Tomas , Olsson Maria Tillfors , Fischer Håkan , Andersson Jesper , Långström Bengt
Published: December 2004

To reveal areas in the central nervous system of importance for electrodermal control, regional cerebral blood flow (rCBF) was correlated to nonspecific skin conductance fluctuations (NSF) during aversive and nonaversive conditions. Participants viewed a TV screen displaying white noise or snake videotapes presented both with and without electric shocks given to the right hand. H215O positron emission tomography was used to measure rCBF, and the constant voltage technique was used to measure NSF from the left hand. Electrodermal activity was positively related to rCBF in the left primary motor cortex (MI, Brodmann's Area 4) and bilaterally in the anterior (Areas 24 and 32) and posterior cingulate cortex (Area 23). Negative relations were observed bilaterally in the secondary visual cortex (Areas 18 and 19) and the right inferior parietal cortex (Area 39), with a tendency also for the right insular cortex (Areas 13, 15, and 16). Because results from lesion and stimulation studies in humans converge with the present imaging results, we conclude that the cingulum and the motor cortex, in addition to the parietal and possibly the insular cortex, form part of one or several distributed neural network(s) involved in electrodermal control. Because these areas also support anticipation, affect, and locomotion, electrodermal responses seem to reflect cognitively or emotionally mediated motor preparation.
Prefrontal cortex glucose metabolism and startle eyeblink modification abnormalities in unmedicated schizophrenia patients
Authors: Hazlett Erin A. , Buchsbaum Monte S. , Haznedar M. Mehmet , Singer Melissa B. , Germans Marja K. , Schnur David B. , Jimenez Edward A. , Buchsbaum Bradley R. , Troyer Bill T.
Published: December 2004

Attentional modulation of the startle reflex was studied in 16 unmedicated schizophrenia patients and 15 control individuals during the 18F‐2‐deoxyglucose uptake period for positron emission tomography. In a task involving attended, ignored, and novel tones that served as prepulses, control individuals showed greater prepulse inhibition (PPI) at 120 ms and greater prepulse facilitation at 4,500 ms during attended than during ignored prepulses; the amount of PPI and facilitation during novel prepulses was intermediate. In contrast, patients failed to show differential PPI at 120 ms and tended to show greater facilitation at 4,500 ms during novel prepulses. For control individuals, greater PPI was associated with higher relative metabolic activity rates in prefrontal (Brodmann Areas 8, 9, and 10 bilaterally) and lower in visual cortex. Patients showed this relationship only for Area 10 on the left. Patients also had low metabolism in superior, middle, and inferior prefrontal cortex. Consistent with animal models, our results demonstrate the importance of the functional integrity of prefrontal cortex to PPI modulation.
Emotional arousal and activation of the visual cortex: An fMRI analysis
Authors: Lang Peter J. , Bradley Margaret M. , Fitzsimmons Jeffrey R. , Cuthbert Bruce N. , Scott James D. , Moulder Bradley , Nangia Vijay
Published: December 2004

Functional activity in the visual cortex was assessed using functional magnetic resonance imaging technology while participants viewed a series of pleasant, neutral, or unpleasant pictures. Coronal images at four different locations in the occipital cortex were acquired during each of eight 12‐s picture presentation periods (on) and 12‐s interpicture interval (off). The extent of functional activation was larger in the right than the left hemisphere and larger in the occipital than in the occipitoparietal regions during processing of all picture contents compared with the interpicture intervals. More importantly, functional activity was significantly greater in all sampled brain regions when processing emotional (pleasant or unpleasant) pictures than when processing neutral stimuli. In Experiment 2, a hypothesis that these differences were an artifact of differential eye movements was ruled out. Whereas both emotional and neutral pictures produced activity centered on the calcarine fissure (Area 17), only emotional pictures also produced sizable clusters bilaterally in the occipital gyrus, in the right fusiform gyrus, and in the right inferior and superior parietal lobules.
Cerebral event‐related potentials associated with selective attention to color: Developmental changes from childhood to adulthood
Authors: van der Stelt Odin , Kok Albert , Smulders Fren T.Y. , Snel Jan , Gunning W. Boudewijn
Published: December 2004

Event‐related potentials were recorded from 80 participants ranging in age from 7 to 24 years while they attended selectively to stimuli with a specified color (red or blue) in an attempt to detect the occurrence of target stimuli. Color attention effects were identified as frontal selection positivity (FSP; 140–275 ms), selection negativity (SN; 150–300 ms), and N2b (200–450 ms), whereas target detection was reflected in P3b (300–700 ms). There were age‐related decreases in the latencies of FSP, N2b, and P3b that paralleled decreases in reaction time and error rates. Also, the SN amplitude increased with advancing age, whereas both N2b and P3b showed changes in scalp topography. These results represent neurophysiological evidence that the efficiency of visual selective processes increases during childhood and adolescence. Developmental growth may take place at both relatively early and late levels of visual selective information processing.
Memory changes with normal aging: Behavioral and electrophysiological measures
Authors: Joyce Carrie A. , Paller Ken A. , McIsaac Heather K. , Kutas Marta
Published: December 2004

We examined performance in young and elderly on an implicit (lexical decision) and an explicit (recognition) memory test. The difference in lexical decision times between old and new words was equivalent in the two groups, although the elderly were slower. In both groups, recognition accuracy (lower in the elderly) was higher following semantic than nonsemantic encoding, whereas lexical decision times were unaffected. Divergent brain potentials for old and new words during lexical decisions constituted a repetition effect, which reflected greater positivity (200–800 ms) for old words, particularly over the left hemisphere; this effect was smaller and later in the elderly. An electrophysiological marker of enhanced recollection for words from the semantic encoding task took the form of a left‐sided positivity (500–800 ms). The effect was smaller in the elderly than the young, providing an additional index of their impaired recognition processes.
Schizophrenic patients show facial reactions to emotional facial expressions
Authors: Kring Ann M. , Kerr Sandra L. , Earnst Kelly S.
Published: December 2004

Facial reactions in schizophrenic patients were assessed via electromyography (EMG) in response to pictures of facial expressions. Male patients and nonpatient controls viewed photographs of positive and negative facial expressions while EMG activity from the corrugator and zygomatic muscle regions was recorded. Both schizophrenic patients and controls exhibited greater zygomatic reactivity in response to positive pictures than in response to negative pictures and greater corrugator reactivity in response to negative pictures than in response to positive pictures. Schizophrenic patients exhibited greater corrugator reactivity than did nonpatient controls. Implications for understanding emotion expression and perception in schizophrenic patients are discussed.
How many nights are enough? The short‐term stability of sleep parameters in elderly insomniacs and normal sleepers
Authors: Wohlgemuth William K. , Edinger Jack D. , Fins Ana I. , Sullivan Robert J.
Published: December 2004

Temporal stability is an important fundamental quality when measuring sleep parameters, yet it has been infrequently assessed. Generalizability theory was used to estimate the short‐term temporal stability of five variables commonly used to characterize insomnia: sleep onset latency, total sleep time, wake after sleep onset, time in bed, and sleep efficiency. Estimates were calculated for 32 elderly primary insomniacs and 32 elderly normal sleepers, both in the lab and at home, using both sleep logs and polysomnography (PSG). A week of recording using either PSG or sleep logs was typically sufficient to achieve adequate stability (defined as G coefficient of at least 0.80) with some notable exceptions: (a) when using log‐derived measures with insomniacs, a 3‐week average was necessary for wake after sleep onset and (b) more than a 2‐week average was necessary for sleep onset latency. Because of the substantial commitment involved in the physiological recording of sleep, alternative forms of aggregation are considered with the intent of improving temporal stability.
Perceptual and response interference in children with attention‐deficit hyperactivity disorder, and the effects of methylphenidate
Authors: Jonkman L.M. , Kemner C. , Verbaten M.N. , van Engeland H. , Kenemans J.L. , Camfferman G. , Buitelaar J.K. , Koelega H.S.
Published: December 2004

Fourteen children with attention‐deficit hyperactivity disorder (ADHD) and 14 normal control children were compared with respect to stimulus‐ and response‐related processes. Subjects with ADHD took part in two additional sessions under methylphenidate or placebo. In both experiments, performance and electrophysiological measures such as the P2, N2, and P3 components of event‐related potential and electromyogram (EMG) activity were measured during an Eriksen flanker task. In both groups of children, reaction times (RTs) to arrow stimuli incongruent with the target were longer than those to neutral stimuli (response interference), which were again slower than RTs to target‐alone stimuli (perceptual interference). Children with ADHD made more errors to incongruent stimuli and showed more response interference. For correct responses, no differences between the groups in response interference effects on reaction time, P2, N2, and P3 latency, or EMG onset were found. Methylphenidate had a general enhancing effect on accuracy but did not specifically reduce interference from the flanking stimuli. Methylphenidate had no effects on RT, N2 and P2 latency, P3 amplitude or latency, or EMG activity. The conclusion that methylphenidate did not influence response processes contrasts sharply with findings reported by authors using the Sternberg memory search task.
For Distinguished Contributions to Psychophysiology: David Lykken
Authors: Fowles Don C.
Published: December 2004

At the Thirty‐Eighth Annual Meeting of the Society for Psychophysiological Research (SPR), the award for Distinguished Contributions to Psychophysiology was presented to David Lykken. The following is based on the text of the citation given by Don Fowles on behalf of the Society's Awards Committee on September 26, 1998.
Dissociation of the mismatch negativity and processing negativity attentional waveforms with nitrous oxide
Authors: Pang Elizabeth W. , Fowler Barry
Published: December 2004

In Näätänen's model of early attention, the role of arousal in influencing the permanent feature detection system (indexed by mismatch negativity [MMN]) and the temporary feature‐detection system (indexed by processing negativity [PN]) is unclear. To address this question, we investigated the effects of the anesthetic gas nitrous oxide (N2O) on the MMN and PN. Ten subjects performed a dichotic listening task in which discrimination difficulty and breathing mixture (air or 25% N2O) were manipulated factorially. MMN, PN, N1 and P300 at Fz, Cz, and Pz, as well as reaction time (RT), were measured. N2O had no effect on the PN, but decreased MMN amplitude. As expected, N2O decreased the amplitude of the N1 and P300 and increased the latency of the P300 and RT. The dissociation of MMN and PN by N2O suggests that this agent decreases the ability to detect automatic stimulus change without affecting voluntary selective attention. We interpret these results as indicating that arousal has multidimensional effects on early attentional mechanisms. These dimensions can be differentiated chemically by neurotransmitters in the reticular formation of the brain.
Secretory immunoglobulin A and cardiovascular reactions to mental arithmetic, cold pressor, and exercise: Effects of beta‐adrenergic blockade
Authors: Winzer Alexandra , Ring Christopher , Carroll Douglas , Willemsen Gonneke , Drayson Mark , Kendall Martin
Published: December 2004

We investigated the influence of sympathetic nervous system processes on mucosal immunity by comparing the effects of beta‐adrenoceptor blockade with 40 mg propranolol and placebo on secretory immunoglobulin A (sIgA) at rest and during paced serial arithmetic, cold pressor, and submaximal cycling. These tasks produced patterns of cardiovascular activity indicative of combined alpha‐ and beta‐adrenergic, alpha‐adrenergic, and beta‐adrenergic activation, respectively. The effectiveness of the beta blockade was confirmed by the attenuation under propranolol of the shortening of the cardiac preejection period and the tachycardia elicited by mental arithmetic and exercise. The cold pressor test did not affect sIgA under either the placebo or the propranolol. Mental arithmetic increased sIgA concentration, and this increase was not blocked by propranolol. Exercise elicited increases in both sIgA concentration and sIgA secretion rate, which were not diminished by beta blockade. These data suggest that sIgA is not regulated by beta‐adrenergic mechanisms.
An ERP correlate of metrical stress in spoken word recognition
Authors: Böcker Koen B.E. , Bastiaansen Marcel C.M. , Vroomen Jean , Brunia Cornelis H.M. , de Gelder Beatrice
Published: December 2004

Rhythmic properties of spoken language such as metrical stress, that is, the alternation of strong and weak syllables, are important in speech recognition of stress‐timed languages such as Dutch and English. Nineteen subjects listened passively to or discriminated actively between sequences of bisyllabic Dutch words, which started with either a weak or a strong syllable. Weak‐initial words, which constitute 12% of the Dutch lexicon, evoked more negativity than strong‐initial words in the interval between P2 and N400 components of the auditory event‐related potential. This negativity was denoted as N325. The N325 was larger during stress discrimination than during passive listening. N325 was also larger when a weak‐initial word followed a sequence of strong‐initial words than when it followed words with the same stress pattern. The latter difference was larger for listeners who performed well on stress discrimination. It was concluded that the N325 is probably a manifestation of the extraction of metrical stress from the acoustic signal and its transformation into task requirements.
Learned maintenance of pain: Muscle tension reduces central nervous system processing of painful stimulation in chronic and subchronic pain patients
Authors: Knost Bärbel , Flor Herta , Birbaumer Niels , Schugens Markus M.
Published: December 2004

The effect of level of muscle tension on the perception of painful stimuli was assessed in 13 chronic back pain patients, 14 subjects at high risk for chronic back pain, and 14 matched healthy controls. Subjects received painful intracutaneous electric stimuli to the forearm or the lower back while they produced either high or low muscle tension levels. Visual analog scale (VAS) ratings of acute pain were obtained after each trial. Electroencephalograms, electromyograms, skin conductance levels, and blood pressure were measured during the trials. Although subjective pain ratings were not significantly affected by muscle tension levels, the chronic pain patients displayed elevated N150 and N150/P260 amplitudes of the somatosensory‐evoked potentials in the low as compared to the high muscle tension condition. The high risk group showed a trend toward higher N150 amplitudes in the low as compared to the high tension condition. The results of this study partially support the hypothesis that increases in muscle tension might serve as a pain‐reducing mechanism in chronic pain patients and those at risk for chronicity, thus leading to a vicious pain‐tension cycle.
Independence of valence modulation and prepulse inhibition of startle
Authors: Hawk Larry W. , Cook Edwin W.
Published: December 2004

This study sought to determine whether prepulse inhibition and valence modulation of startle are independent, both within and across individuals. Acoustic probes (105 dB) were delivered as 68 undergraduates viewed pleasant, neutral, and unpleasant pictures. Weak acoustic stimuli (8 dB above background) preceded half of the probes by 120 ms. As expected, startles were larger during unpleasant than during pleasant pictures, and smaller on prepulse than no‐prepulse trials. In general, valence modulation and prepulse inhibition of startle were unrelated. That is, prepulse inhibition was consistent across affective states, valence modulation did not differ between no‐prepulse and prepulse trials, and valence modulation and prepulse inhibition effects were uncorrelated across individuals. Analysis of raw and percent modification scores generally led to similar conclusions. It is concluded that valence modulation and prepulse inhibition are independent startle modulatory phenomena, although this conclusion is tempered by a finding of poor internal consistency reliability for valence modulation.
Error monitoring during reward and avoidance learning in high‐ and low‐socialized individuals
Authors: Dikman Ziya V. , Allen John J.B.
Published: December 2004

The error‐related negativity (ERN) is a response‐locked brain potential generated when individuals make mistakes during simple decision‐making tasks. In the present study, we examined ERN under conditions of reward and punishment, among participants who scored extremely low or high on the socialization scale of the California Psychological Inventory (CPI). Participants completed a forced‐choice task, and were rewarded for correct responses in half the trials, and punished for incorrect responses in the remaining trials. A significant interaction between socialization (SO) and condition revealed that low‐SO participants produced smaller ERNs during the punishment task than during the reward task, whereas high‐SO participants produced similar ERNs in both conditions. Reaction time and electromyogram data essentially bolster the interpretation that the ERN effects reflect differences in error salience for high‐SO and low‐SO participants, and are consistent with the avoidance‐learning deficits seen in psychopathy.
The effect of warning stimulus modality on blink startle modification in reaction time tasks
Authors: Lipp Ottmar V. , Siddle David A.T. , Dall Patricia J.
Published: December 2004

The present study investigated the effects of lead stimulus modality on modification of the acoustic startle reflex during three reaction time tasks. In Experiment 1, participants (N= 48) were required to press a button at the offset of one stimulus (task relevant) and to ignore presentations of a second (task irrelevant). Two tones that differed in pitch or two lights served as signal stimuli. Blink startle was elicited during some of the stimuli and during interstimulus intervals. Skin conductance responses were larger during task‐relevant stimuli in both groups. Larger blink facilitation during task‐relevant stimuli was found only in the group presented with auditory stimuli, whereas larger blink latency shortening during task‐relevant stimuli was found in both groups. Experiment 2 (N= 32) used only a task‐relevant stimulus. Blink magnitude facilitation was significant only in the group presented with tones, whereas blink latency shortening was significant in both groups. Experiment 3 (N= 80) used a go/nogo task that required participants to press a button if one element of a compound stimulus ended before the second, but not if the asynchrony was reversed. The offset asynchrony was varied between groups as a manipulation of task difficulty. Startle magnitude facilitation was larger during acoustic than during visual stimuli and larger in the easy condition. The present data indicate that startle facilitation in a reaction time task is affected by stimulus modality and by task demands. The effects of the task demands seem to be independent of lead stimulus modality.
Development of multimodal attention in young infants: Modification of the startle reflex by attention
Authors: Richards John E.
Published: December 2004

This study examined the effect of attention engagement to compound auditory‐visual stimuli on the modification of the startle blink reflex in infants. Infants at 8, 14, 20, or 26 weeks of age were presented with interesting audiovisual stimuli. After stimulus onset, at delays defined by heart rate changes known to be associated with sustained attention or attention disengagement, blink reflexes were elicited by visual or auditory stimuli. Blink amplitude to either visual or auditory stimuli was enhanced when the infants were engaged in attention to the foreground auditory‐visual stimuli relative to control trials with no foreground patterns. This enhancement of the blink amplitude increased from 8 to 26 weeks of age. In contrast to selective modality enhancement for single‐modality foreground stimuli, these results show that these multimodal stimuli engage both visual and auditory attention systems in this age range.
Comparison of electrodermal constant voltage and constant current recording techniques using the phase angle between alternating voltage and current
Authors: Schaefer Florian , Boucsein Wolfram
Published: December 2004

If electrodermal activity is recorded with direct current, constant voltage and constant current measurements result in different dependencies of electrodermal reactions on the actual electrodermal level. The present study demonstrates empirically that such a problem does not exist when instead the phase angle changes between alternating current and voltage are obtained. Forty subjects were subjected to a 20‐trial habituation series on two different occasions, in which electrodermal level variations were induced by room temperature changes. A multiplexing system was used to enable quasi‐simultaneous constant current and constant voltage recording under both direct and alternating current measurement conditions. If the alternating current technique was applied and electrodermal responses were expressed as changes of phase angle between voltage and current, electrodermal recordings with constant voltage and with constant current provided equivalent results, even if electrodermal levels were considerably different. Therefore, using the phase angle method instead of the conventional direct current methods will finally resolve the problem of differential level dependency in electrodermal recording. A further advantage will be that electrode and skin polarization are prevented by the use of alternating current.
Orienting response reinstatement and dishabituation: Effects of substituting, adding, and deleting components of nonsignificant stimuli
Authors: Ben‐Shakhar Gershon , Gati Itamar , Ben‐Bassat Naomi , Sniper Galit
Published: December 2004

The prediction that orienting response (OR) reinstatement is negatively related to the measure of common features, shared by the stimulus input and representations of preceding events, and positively related to the measure of their distinctive features, was examined. A nonsignificant test stimulus (TS) was presented after nine repetitions of a standard stimulus (SS), followed by two additional repetitions of SS. TS was created by either substituting 0, 1, or 2 components of SS (Experiment 1), or by either adding or deleting 0, 1, or 2 components of SS (Experiment 2). Skin conductance changes to TS (OR reinstatement) and the subsequent SS (dishabituation) were used as dependent measures. The results of Experiment 1 supported the prediction that substituting components of neutral stimuli affects OR reinstatement, with a larger effect for between‐categories than within‐categories substitution. Experiment 2 demonstrated that adding and deleting components similarly affects OR reinstatement.
Selective influence of the menstrual cycle on perception of stimuli with reproductive significance: An event‐related potential study
Authors: Krug R. , Plihal W. , Fehm H.L. , Born J.
Published: December 2004

In this study, we examined changes in the event‐related potential (ERP) to stimuli with and without reproductive significance occurring during the menstrual cycle. Eleven spontaneously cycling women were tested during three menstrual phases (menses, ovulatory phase, luteal phase) differing in plasma concentrations of gonadal hormones. ERPs were recorded while subjects were presented with slides showing pictures from four different stimulus categories (sexual stimuli, babies, people occupied with body care, ordinary people). Slides were presented randomly in the context of two tasks, requiring either affective processing (i.e., to judge the emotional content of a slide as positive, neutral, or negative) or structural processing (i.e., to estimate the number of parallel thin lines inserted in each picture). Menstrual phase primarily affected a late positive component (LPC) peaking 550–600 ms poststimulus. The effects were as follows: (i) During the ovulatory phase, amplitude of the LPC to sexual stimuli was larger than that evoked by the other stimulus categories. (ii) This relationship was not apparent during the other menstrual phases or (iii) during the ovulatory phase when the task required structural processing. The ovulatory increase in LPC positivity to sexual stimuli suggests a greater valence of these stimuli during a phase of increased sexual desire. The data indicate a specific effect of the menstrual cycle on the processing of sexual stimuli that increases with deeper emotional processing.