ERP

Distribution by Scientific Domains

Terms modified by ERP

  • erp component
  • erp data
  • erp environment
  • erp measure
  • erp project
  • erp studies
  • erp study
  • erp system

  • Selected Abstracts


    Group cognitive behavioural therapy for obsessive,compulsive disorder: a systematic review and meta-analysis

    ACTA PSYCHIATRICA SCANDINAVICA, Issue 2 2009
    H. Jónsson
    Objective:, Behaviour therapy with exposure and response prevention (ERP) or cognitive behavioural therapy (CBT) including ERP are considered the psychological treatments of choice for obsessive,compulsive disorder (OCD), but group CBT/ERP has received relatively little research attention in the treatment of OCD. The aim of this study was to provide a meta-analysis of the effectiveness of group CBT/ERP for OCD. Method:, A systematic literature search was conducted and studies were meta-analysed by means of the Cochrane Review Manager Program with measures of i) pre- to post-effect sizes (ES) and ii) between-group ES in comparison with different control conditions. Outcome was primarily measured on the Y-BOCS and ES was calculated in the form of Cohens d. Results:, Thirteen trials were included in the meta-analysis. The overall pre,post-ES of these trials of 1.18 and a between-group ES of 1.12 compared with waiting list control in three randomized controlled studies indicate that group CBT/ERP is an effective treatment for OCD. Group CBT achieved better results than pharmacological treatment in two studies. One study found no significant differences between individual and group CBT. Conclusion:, Group CBT is an effective treatment for OCD, but more studies are needed to compare the effectiveness of group and individual treatment formats. [source]


    Annotation: What electrical brain activity tells us about brain function that other techniques cannot tell us , a child psychiatric perspective

    THE JOURNAL OF CHILD PSYCHOLOGY AND PSYCHIATRY AND ALLIED DISCIPLINES, Issue 5 2007
    Tobias Banaschewski
    Background:, Monitoring brain processes in real time requires genuine subsecond resolution to follow the typical timing and frequency of neural events. Non-invasive recordings of electric (EEG/ERP) and magnetic (MEG) fields provide this time resolution. They directly measure neural activations associated with a wide variety of brain states and processes, even during sleep or in infants. Mapping and source estimation can localise these time-varying activation patterns inside the brain. Methods: Recent EEG/ERP research on brain functions in the domains of attention and executive functioning, perception, memory, language, emotion and motor processing in ADHD, autism, childhood-onset schizophrenia, Tourette syndrome, specific language disorder and developmental dyslexia, anxiety, obsessive-compulsive disorder, and depression is reviewed. Results:, Over the past two decades, electrophysiology has substantially contributed to the understanding of brain functions during normal development, and psychiatric conditions of children and adolescents. Its time resolution has been important to measure covert processes, and to distinguish cause and effect. Conclusions:, In the future, EEG/ERP parameters will increasingly characterise the interplay of neural states and information processing. They are particularly promising tools for multilevel investigations of etiological pathways and potential predictors of clinical treatment response. [source]


    Visual event-related potentials in children with phenylketonuria

    ACTA PAEDIATRICA, Issue 1 2000
    RM Henderson
    Visual event-related potentials (ERPs) were examined in 16 children (aged 5,14 y) with phenylketonuria (PKU) and 16 age- and sex-matched controls. Lifetime median measures of phenylalanine (Phe) were 230-460 ,mol/l. The most recent Phe levels were 56,624 ,mol/l. ERPs were recorded whilst the children performed a discrimination task. All stimuli were square wave gratings degree, which appeared for 33 ms. A response to an infrequent grating that differed in orientation or spatial frequency was required. The older children with PKU had a delay in the first peak (P1) of the ERP, and age-related changes in the amplitude of P1. There was attenuation of the second peak across age groups in PKU. There was no evidence of reduced response accuracy or longer reaction times in children with PKU. Latencies of the cognitive P3 were not delayed in PKU. The delayed early peaks are consistent with previous studies that have shown delayed visual evoked potentials in PKU. The lack of differences in reaction time and P3 may be due to relatively good Phe control in children with PKU, or to the simplicity of the task. Suggestions are made for future ERP studies of PKU. [source]


    Neurophysiologic evaluation of early cognitive development in high-risk infants and toddlers

    DEVELOPMENTAL DISABILITIES RESEARCH REVIEW, Issue 4 2005
    Raye-Ann deRegnier
    Abstract New knowledge of the perceptual, discriminative, and memory capabilities of very young infants has opened the door to further evaluation of these abilities in infants who have risk factors for cognitive impairments. A neurophysiologic technique that has been very useful in this regard is the recording of event-related potentials (ERPs). The event-related potential (ERP) technique is widely used by cognitive neuroscientists to study cognitive abilities such as discrimination, attention, and memory. This method has many attractive attributes for use in infants and children as it is relatively inexpensive, does not require sedation, has excellent temporal resolution, and can be used to evaluate early cognitive development in preverbal infants with limited behavioral repertories. In healthy infants and children, ERPs have been used to gain a further understanding of early cognitive development and the effect of experience on brain function. Recently, ERPs have been used to elucidate atypical memory development in infants of diabetic mothers, difficulties with perception and discrimination of speech sounds in infants at risk for dyslexia, and multiple areas of cognitive differences in extremely premature infants. Atypical findings seen in high-risk infants have correlated with later cognitive outcomes, but the sensitivity and specificity of the technique has not been studied, and thus evaluation of individual infants is not possible at this time. With further research, this technique may be very useful in identifying children with cognitive deficits during infancy. Because even young infants can be examined with ERPs, this technique is likely to be helpful in the development of focused early intervention programs used to improve cognitive function in high-risk infants and toddlers. © 2005 Wiley-Liss, Inc. MRDD Research Reviews 2005;11:317,324. [source]


    Group cognitive behavioural therapy for obsessive,compulsive disorder: a systematic review and meta-analysis

    ACTA PSYCHIATRICA SCANDINAVICA, Issue 2 2009
    H. Jónsson
    Objective:, Behaviour therapy with exposure and response prevention (ERP) or cognitive behavioural therapy (CBT) including ERP are considered the psychological treatments of choice for obsessive,compulsive disorder (OCD), but group CBT/ERP has received relatively little research attention in the treatment of OCD. The aim of this study was to provide a meta-analysis of the effectiveness of group CBT/ERP for OCD. Method:, A systematic literature search was conducted and studies were meta-analysed by means of the Cochrane Review Manager Program with measures of i) pre- to post-effect sizes (ES) and ii) between-group ES in comparison with different control conditions. Outcome was primarily measured on the Y-BOCS and ES was calculated in the form of Cohens d. Results:, Thirteen trials were included in the meta-analysis. The overall pre,post-ES of these trials of 1.18 and a between-group ES of 1.12 compared with waiting list control in three randomized controlled studies indicate that group CBT/ERP is an effective treatment for OCD. Group CBT achieved better results than pharmacological treatment in two studies. One study found no significant differences between individual and group CBT. Conclusion:, Group CBT is an effective treatment for OCD, but more studies are needed to compare the effectiveness of group and individual treatment formats. [source]


    Brain responses to surprising sounds are related to temperament and parent,child dyadic synchrony in young children

    DEVELOPMENTAL PSYCHOBIOLOGY, Issue 6 2010
    Anu-Katriina Pesonen
    Abstract This study investigated the relationship between temperament characteristics, parent,child dyadic synchrony and auditory event-related potentials (ERP) in 15 two-year-old children. Temperament was assessed with the Early Childhood Behavior Questionnaire, and parent,child dyadic synchrony was analyzed from video-taped play situations. Involuntary switching of attention toward surprising sounds was measured with auditory ERPs by quantifying the P3a response for repeated and nonrepeated novel, naturally varying sounds, presented in a continuous repetitive sound sequence. Lower negative emotionality, higher effortful control and higher dyadic synchrony were associated with larger P3a responses to repeated novel sounds. The results demonstrate that temperament is related to P3a responses in early childhood, and that parent,child synchrony associates with both temperament and P3a responses in a theoretically meaningful way. © 2010 Wiley Periodicals, Inc. Dev Psychobiol 52: 513,523, 2010. [source]


    Event-related potential (ERP) indices of infants' recognition of familiar and unfamiliar objects in two and three dimensions

    DEVELOPMENTAL SCIENCE, Issue 1 2006
    Leslie J. Carver
    We measured infants' recognition of familiar and unfamiliar 3-D objects and their 2-D representations using event-related potentials (ERPs). Infants differentiated familiar from unfamiliar objects when viewing them in both two and three dimensions. However, differentiation between the familiar and novel objects occurred more quickly when infants viewed the object in 3-D than when they viewed 2-D representations. The results are discussed with respect to infants' recognition abilities and their understanding of real objects and representations. This is the first study using 3-D objects in conjunction with ERPs in infants, and it introduces an interesting new methodology for assessing infants' electrophysiological responses to real objects. [source]


    Links between social and linguistic processing of speech in preschool children with autism: behavioral and electrophysiological measures

    DEVELOPMENTAL SCIENCE, Issue 1 2005
    Patricia K. Kuhl
    Data on typically developing children suggest a link between social interaction and language learning, a finding of interest both to theories of language and theories of autism. In this study, we examined social and linguistic processing of speech in preschool children with autism spectrum disorder (ASD) and typically developing chronologically matched (TDCA) and mental age matched (TDMA) children. The social measure was an auditory preference test that pitted ,motherese' speech samples against non-speech analogs of the same signals. The linguistic measure was phonetic discrimination assessed with mismatch negativity (MMN), an event-related potential (ERP). As a group, children with ASD differed from controls by: (a) demonstrating a preference for the non-speech analog signals, and (b) failing to show a significant MMN in response to a syllable change. When ASD children were divided into subgroups based on auditory preference, and the ERP data reanalyzed, ASD children who preferred non-speech still failed to show an MMN, whereas ASD children who preferred motherese did not differ from the controls. The data support the hypothesis of an association between social and linguistic processing in children with ASD. [source]


    Immature cortical responses to auditory stimuli in specific language impairment: evidence from ERPs to rapid tone sequences

    DEVELOPMENTAL SCIENCE, Issue 4 2004
    D.V.M. Bishop
    Event-related potentials (ERPs) to tone pairs and single tones were measured for 16 participants with specific language impairment (SLI) and 16 age-matched controls aged from 10 to 19 years. The tone pairs were separated by an inter-stimulus interval (ISI) of 20, 50 or 150 ms. The intraclass correlation (ICC) was computed for each participant between the ERP to a single tone and the ERP to the tone pair. A high ICC indicates that the brain response to a tone pair is similar to that for a single tone. ICCs were significantly higher at short than at long ISIs. At 50-ms ISI, ICCs were higher for younger than older participants. Age and ISI interacted with SLI status: ERPs of older participants with SLI differed from age-matched controls, and resembled ERPs of younger controls, consistent with a theory of immature auditory processing in SLI. [source]


    Retroperitoneal perforation of a pancreatic cyst during endoscopic retrograde pancreatography

    DIGESTIVE ENDOSCOPY, Issue 2 2003
    TOMOYUKI KAWAKITA
    A 70-year-old man was admitted to Ueno Municipal Hospital, Ueno, Japan, for evaluation of abdominal distension. Computed tomography showed a 1 × 1 cm cyst at the pancreas tail. Endoscopic retrograde pancreatography (ERP) showed a normal pancreatic duct after the first gentle injection and an enhanced cyst at the pancreas tail. Extravasation of the contrast medium occurred from the pancreatic duct to the superior-dorsal extrapancreas at the same time of the next low-pressure manual injection. Computed tomography showed extravasation of the contrast medium from the pancreas cyst to the retroperitoneal space after ERP. It was considered that the cyst wall weakness, in addition to slight elevated pancreatic duct pressure, caused the disruption of the cyst wall. [source]


    The promotion of green electricity in Europe: present and future

    ENVIRONMENTAL POLICY AND GOVERNANCE, Issue 4 2004
    Pablo del Río
    Public support schemes for electricity from renewable energy sources (RES-E) are undergoing a period of change. Two interrelated processes can be discerned at both the EU and member state (MS) levels. On the one hand, the RES-E Directive sets targets for consumption of renewable electricity for the year 2010 and opens the possibility that the European Commission sets a community support framework for RES-E promotion in the future. On the other hand, different types of support scheme have been and are used by countries in order to promote the deployment of renewable electricity. A move from tendering/bidding systems and feed-in tariffs to tradable green certificates can be observed in some MSs. This move may take place in the future in some other MSs while others will certainly continue to rely on their current scheme. This paper provides an overview and assessment of the instruments currently used to promote renewable electricity in Europe and considers some possible trends in the choice of support schemes in the future. Copyright © 2004 John Wiley &,Sons, Ltd and ERP,Environment. [source]


    Politics, industry and the regulation of industrial greenhouse-gas emissions in the UK and Germany

    ENVIRONMENTAL POLICY AND GOVERNANCE, Issue 4 2004
    Ian Bailey
    This paper assesses the impact of ,new' environmental policy instruments (NEPIs), such as eco-taxes, tradable permits and environmental agreements, on the politics of regulating industrial greenhouse-gas emissions. Intense academic debate surrounds the extent to which environmental policy is driven by the public interest, public choices between actor and stakeholder interests, or embedded institutional traditions. However, the effects on environmental politics of the recent shift from direct regulation to NEPIs remain seriously under-researched. Surveys and interviews with industry and policy-makers on the implementation of United Kingdom and German climate policy indicate that, although economic pressures do influence the design of policy instruments, public choice is far from dominant; nor are industry reactions to particular NEPIs uniform between countries. This suggests that national institutional traditions are far more influential in informing policy choices and industry reactions to policy innovations than is often acknowledged. Copyright © 2004 John Wiley &,Sons, Ltd and ERP,Environment. [source]


    Language-Related Potentials in Temporal Lobe Epilepsy Before and After Surgical Treatment

    EPILEPSIA, Issue 2000
    Toshihiko Ito
    Purpose: Temporal lobectomy has contributed to treatment for medically intractable epilepsies. However, influence of the surgical treatment on cognitive function is not still clear, especially from the electrophysiological viewpoint. N400, an event related potential (ERP) named for its negative polarity and peak latency of 400 ms, is reported to be an electrophysiological sign of neural activities associated with semantic priming in language perception. In the present study, ERPs are applied to evaluate the cognitive function of temporal lobe epilepsy before and after temporal lobectomy. Methods: Two patients with intractable temporal lobe epilepsy participated in this study. Fifteen normal subjects served as controls. The incongruous sentence task (Kutas and Hillyard 1980) was used to record N400 components in an auditory modality. Two types of sentences (40 Japanese sentences for each type) were prepared, in which the terminal words were either semantically congruent or incongruent. The scntences were randomly presented at approximately 65 dB SPL peak intensity. ERPs were recorded according to the international 10,20 system, with a balanced non-cephalic electrode reference and 2 1 channels. The band-pass filter was set from 0.5 to 30 Hz, and the ERPs were sampled at 500 Hz from 200 ms before the onset of terminal words to 824 ms post-stimulus. Waves were calculated by subtracting ERPs in the congruent condition from those in the incongruent condition. N400 was scored as the most negative point between 250 and 450 ms in the subtraction waves. Amplitudes were measured from the baseline of 100 ms before the terminal words. Motor responses were also measured with a right index finger, to estimate the accuracy of understanding sentences. Results: Case I was a 22-year-old male who had intractable epilepsy for 7 years. Magnetic resonance imaging (MRI) showed high-intensity signals in the right amygdalo-hippocampal region. The epileptic seizures were confirmed to originate from the region hy electroencephalography/closed-circuit television monitoring, and single-photon-emission computed tomography. ERPs were recorded I month before and after the right anterior temporal lobectomy. Before the surgery, the rate of correct responses showed no difference between the patient (96 %) and the controls (96 %). The amplitudes of N400 for the patient reduced in the right frontal and central areas (F4, C4), comparing to 99 % confidence limit for control subjects. After the surgery, the rate of correct responses was 97 %, and the amplitudes reduced in the right central, parietal, and posterior temporal areas (C4, P4, 0 2, T6). Case 2 (37-year-old female) had intractable epilepsy for 30 years. MRI showed brain atrophy in the right hippocampal region. The epileptic seizures were confirmed to originate from the region. N400 was recorded 3 months after the resection. The rate of correct responses was 95 %. The amplitudes of N400 were lower in the right frontal, parietal, and temporal areas (electrodes Fp2, F4, P4, T6, Pz), comparing to 99 % confidence limit of controls. Conclusions: Before the lpbectomy, the reduction of amplitudes of N400 indicated that the pathogenesis of intractable temporal lobe epilepsy would influence the process of semantic priming in language perception. After the resection, it was suggested that the right temporal lobectomy might affect the cognitive function in the brain from electrophysiological aspects. We could benefit from further study including analysis of the discrepancy between the amplitudes of N400 and behavioral responses. [source]


    A review of the use of moxidectin in horses

    EQUINE VETERINARY EDUCATION, Issue 10 2008
    J. Schumacher
    Summary Moxidectin has broad-spectrum anti-nematodal and anti-arthropodal activities in the horse but is not effective against tapeworms or flukes. Moxidectin and ivermectin have the same efficacy against internal, adult parasites of horses. Moxidectin, however, is highly effective in eliminating encysted and hypobiotic larval stages of cyathostomins, whereas ivermectin is not. Treatment of horses with moxidectin results in an egg-reappearance period (ERP) of 15,24 weeks. Because of its long ERP, moxidectin is labelled to be used at 12 week intervals. Moxidectin may provide protection against infection by ingested cyathostomin larvae for 2,3 weeks after it is administered. The larvicidal activity of moxidectin has often been compared to that of fenbendazole administered at either 7.5 or 10 mg/kg bwt for 5 consecutive days. The efficacy of fenbendazole, when administered daily for 5 consecutive days at 7.5 or 10 mg/kg bwt, against all stages of cyathostomins is often less than that of moxidectin because resistance of cyathostomins to benzimidazoles is prevalent worldwide, and the 5 day course of fenbendazole does not overcome this resistance. There are now reports of resistance of ascarids to moxidectin. Overt resistance of cyathostomins and a shortened egg re-emergence period after treatment with moxidectin have been reported. Rapid removal of manure by natural fauna can significantly reduce larval nematode concentrations and thereby reduce intervals of anthelmintic treatment. Of the macrocyclic lactones, moxidectin has the least deleterious effect on faecal fauna. [source]


    Delayed visual P3 in unilateral thalamic stroke

    EUROPEAN JOURNAL OF NEUROLOGY, Issue 5 2000
    E. Trinka
    The P3 potential is accepted as a neurophysiological correlate of memory and attention. Delayed latencies were reported in different forms of dementias. Although the generator sites are still under debate, the thalamus may play a crucial role. The aim of this study was to investigate the influence of an unilateral thalamic ischaemic infarction on P3 generation. The event-related P3 component of six patients (2 male, four female; mean age 47 years, range 22,63 years) with unilateral thalamic ischaemic infarction was studied and compared to age-matched controls (five male, nine female; mean age 45.8 years; range 22,69 years). All patients underwent full clinical examination, CCT, and MRI scan. P3 potentials were recorded with a visual three stimulus discrimination paradigm. The mean P3 latency of the patient group to the target stimulus was delayed (469.7 ms, SD = 36.8) compared with the controls (378.8 ms, SD = 51.5; P < 0.05). The mean P3 latency to the unexpected stimulus was delayed in patients with thalamic infarction compared with controls [477 ms (SD = 46.6) vs. 381.2 ms (SD = 48.5); P < 0.001). Delayed P3 components of the event-related potential (ERP) were recorded in six patients with unilateral thalamic infarction, suggesting an important role of the thalamus in the generation of the P3 potential. [source]


    The strength of anticipatory spatial biasing predicts target discrimination at attended locations: a high-density EEG study

    EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 11 2009
    Simon P. Kelly
    Abstract Cueing relevant spatial locations in advance of a visual target results in modulated processing of that target as a consequence of anticipatory attentional deployment, the neural signatures of which remain to be fully elucidated. A set of electrophysiological processes has been established as candidate markers of the invocation and maintenance of attentional bias in humans. These include spatially-selective event-related potential (ERP) components over the lateral parietal (around 200,300 ms post-cue), frontal (300,500 ms) and ventral visual (> 500 ms) cortex, as well as oscillatory amplitude changes in the alpha band (8,14 Hz). Here, we interrogated the roles played by these anticipatory processes in attentional orienting by testing for links with subsequent behavioral performance. We found that both target discriminability (d') and reaction times were significantly predicted on a trial-by-trial basis by lateralization of alpha-band amplitude in the 500 ms preceding the target, with improved speed and accuracy resulting from a greater relative decrease in alpha over the contralateral visual cortex. Reaction time was also predicted by a late posterior contralateral positivity in the broad-band ERP in the same time period, but this did not influence d'. In a further analysis we sought to identify the control signals involved in generating the anticipatory bias, by testing earlier broad-band ERP amplitude for covariation with alpha lateralization. We found that stronger alpha biasing was associated with a greater bilateral frontal positivity at ,390 ms but not with differential amplitude across hemispheres in any time period. Thus, during the establishment of an anticipatory spatial bias, while the expected target location is strongly encoded in lateralized activity in parietal and frontal areas, a distinct non-spatial control process seems to regulate the strength of the bias. [source]


    Isolating endogenous visuo-spatial attentional effects using the novel visual-evoked spread spectrum analysis (VESPA) technique

    EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 12 2007
    Edmund C. Lalor
    Abstract In natural visual environments, we use attention to select between relevant and irrelevant stimuli that are presented simultaneously. Our attention to objects in our visual field is largely controlled endogenously, but is also affected exogenously through the influence of novel stimuli and events. The study of endogenous and exogenous attention as separate mechanisms has been possible in behavioral and functional imaging studies, where multiple stimuli can be presented continuously and simultaneously. It has also been possible in electroencephalogram studies using the steady-state visual-evoked potential (SSVEP); however, it has not been possible in conventional event-related potential (ERP) studies, which are hampered by the need to present suddenly onsetting stimuli in isolation. This is unfortunate as the ERP technique allows for the analysis of human physiology with much greater temporal resolution than functional magnetic resonance imaging or the SSVEP. While ERP studies of endogenous attention have been widely reported, these experiments have a serious limitation in that the suddenly onsetting stimuli, used to elicit the ERP, inevitably have an exogenous, attention-grabbing effect. Recently we have shown that it is possible to derive separate event-related responses to concurrent, continuously presented stimuli using the VESPA (visual-evoked spread spectrum analysis) technique. In this study we employed an experimental paradigm based on this method, in which two pairs of diagonally opposite, non-contiguous disc-segment stimuli were presented, one pair to be ignored and the other to be attended. VESPA responses derived for each pair showed a strong modulation at 90,100 ms (during the visual P1 component), demonstrating the utility of the method for isolating endogenous visuo-spatial attention effects. [source]


    Equity Risk Premiums (ERP): Determinants, Estimation and Implications , A Post-Crisis Update

    FINANCIAL MARKETS, INSTITUTIONS & INSTRUMENTS, Issue 5 2009
    Aswath Damodaran
    First page of article [source]


    Neurocognitive variation in smoking behavior and withdrawal: genetic and affective moderators

    GENES, BRAIN AND BEHAVIOR, Issue 1 2009
    D. E. Evans
    A burgeoning literature suggests that attentional factors are associated with smoking behavior (e.g. direct nicotine effects and smoking withdrawal). This study examined differences in attentional processing between nonsmokers, satiated smokers and overnight nicotine-deprived smokers by comparing the amplitude of the P300 (P3) component of the event-related brain potential (ERP) elicited during a go,nogo task. We also examined the moderating effects of a common dopamine receptor genotype and state negative affect (SNA) on this ERP index of attention. Nonsmokers relative to smokers had greater nogo P3 amplitude. Carrying the A1 allele at the dopamine receptor D2 (DRD2) Taq1A polymorphism site moderated the effects of withdrawal on nogo P3 amplitude, suggesting the A1 allele is a vulnerability marker for withdrawal-related attentional deficits. Increased SNA also predicted attenuated P3 amplitude among deprived smokers. These findings suggest that DRD2 status and SNA moderate the effects of smoking status and withdrawal on neurocognitive variation during attentional processing. This research contributes to a better understanding of the role of individual differences and attentional processing in smoking behavior. [source]


    Independent component analysis of erroneous and correct responses suggests online response control

    HUMAN BRAIN MAPPING, Issue 9 2010
    Sven Hoffmann
    Abstract After errors in reaction tasks, a sharp negative wave emerges in the event-related potential (ERP), the error (related) negativity (Ne or ERN). However, also after correct trials, an Ne-like wave is seen, called CRN or Nc, which is much smaller than the Ne. This study tested the hypothesis whether Ne and Nc reflect the same functional process, and whether this process is linked to online response control. For this purpose, independent component analysis (ICA) was utilized with the EEG data of two types of reaction tasks: a flanker task and a mental rotation task. To control for speed-accuracy effects, speed and accuracy instructions were balanced in a between subjects design. For both tasks ICA and dipole analysis revealed one component (Ne-IC) explaining most of the variance for the difference between correct and erroneous trials. The Ne-IC showed virtually the same features as the raw postresponse ERP, being larger for erroneous compared to correct trials and for the flanker than for the rotation task. In addition, it peaked earlier for corrected than for uncorrected errors. The results favor the hypothesis that Ne and Nc reflect the same process, which is modulated by response correctness and type of task. On the basis of the literature and the present results, we assume that this process induces online response control, which is much stronger in error than correct trials and with direct rather than indirect stimulus response mapping. Hum Brain Mapp, 2010. © 2010 Wiley-Liss, Inc. [source]


    Spatiotemporal mapping of sex differences during attentional processing

    HUMAN BRAIN MAPPING, Issue 9 2009
    Andres H. Neuhaus
    Abstract Functional neuroimaging studies have increasingly aimed at approximating neural substrates of human cognitive sex differences elicited by visuospatial challenge. It has been suggested that females and males use different behaviorally relevant neurocognitive strategies. In females, greater right prefrontal cortex activation has been found in several studies. The spatiotemporal dynamics of neural events associated with these sex differences is still unclear. We studied 22 female and 22 male participants matched for age, education, and nicotine with 29-channel-electroencephalogram recorded under a visual selective attention paradigm, the Attention Network Test. Visual event-related potentials (ERP) were topographically analyzed and neuroelectric sources were estimated. In absence of behavioral differences, ERP analysis revealed a novel frontal-occipital second peak of visual N100 that was significantly increased in females relative to males. Further, in females exclusively, a corresponding central ERP component at around 220 ms was found; here, a strong correlation between stimulus salience and sex difference of the central ERP component amplitude was observed. Subsequent source analysis revealed increased cortical current densities in right rostral prefrontal (BA 10) and occipital cortex (BA 19) in female subjects. This is the first study to report on a tripartite association between sex differences in ERPs, visual stimulus salience, and right prefrontal cortex activation during attentional processing. Hum Brain Mapp 2009. © 2009 Wiley-Liss, Inc. [source]


    Cognitive function, P3a/P3b brain potentials, and cortical thickness in aging

    HUMAN BRAIN MAPPING, Issue 11 2007
    Anders M. Fjell
    Abstract The purpose of the study was to assess the relationship between the P3a/P3b brain potentials, cortical thickness, and cognitive function in aging. Thirty-five younger and 37 older healthy participants completed a visual three-stimuli oddball ERP (event-related potential)-paradigm, a battery of neuropsychological tests, and MRI scans. Groups with short vs. long latency, and low vs. high amplitude, were compared on a point by point basis across the entire cortical mantle. In the young, thickness was only weakly related to P3. In the elderly, P3a amplitude effects were found in parietal areas, the temporoparietal junction, and parts of the posterior cingulate cortex. P3b latency was especially related to cortical thickness in large frontal regions. Path models with the whole sample pooled together were constructed, demonstrating that cortical thickness in the temporoparietal cortex predicted P3a amplitude, which in turn predicted executive function, and that thickness in orbitofrontal cortex predicted P3b latency, which in turn predicted fluid function. When age was included in the model, the relationship between P3 and cognitive function vanished, while the relationship between regional cortical thickness and P3 remained. It is concluded that thickness in specific cortical areas correlates with scalp recorded P3a/P3b in elderly, and that these relationships differentially mediate higher cognitive function. Hum Brain Mapp 2007. © 2007 Wiley-Liss, Inc. [source]


    HR, ERP, and knowledge for competitive advantage

    HUMAN RESOURCE MANAGEMENT, Issue 2 2006
    Cynthia A. Lengnick-Hall
    Enterprise resource planning (ERP) systems are a strong fit with organizations dominated by routine, highly programmed technologies, and tightly regulated operations. However, while these settings are best suited for ERP implementation, they also have the greatest difficulty making use of the knowledge ERP systems generate because of their inherent rigidity, inertia, and resistance to change. This article examines how human resource management practices can help a firm overcome the problems and capitalize on the opportunities that ERP technology presents by facilitating an effective dual-core structure through an emphasis on knowledge management, human capital stewardship, and relationship building. © 2006 Wiley Periodicals, Inc. [source]


    Electrophysiological Signals of Familiarity and Recency in the Infant Brain

    INFANCY, Issue 5 2010
    Kelly A. Snyder
    Electrophysiological work in nonhuman primates has established the existence of multiple types of signals in the temporal lobe that contribute to recognition memory, including information regarding a stimulus's relative novelty, familiarity, and recency of occurrence. We used high-density event-related potentials (ERPs) to examine whether young infants represent these distinct types of information about previously experienced items. Twenty-four different highly familiar and initially novel items were each repeated exactly once either immediately (Experiment 1), or following one intervening item (Experiment 2). A late slow wave (LSW) component of the ERP exhibited neural responses consistent with recency signals over right-central leads, but only when there were no intervening stimuli between repetitions. The LSW also exhibited responses consistent with familiarity signals over anterior-temporal leads, but only when there were intervening stimuli between repetitions. A mid-latency negative component (i.e., the Nc) also distinguished familiar from novel items, but did not exhibit a pattern of responding consistent with familiarity signals. These findings suggest that infants encode information about a variety of objects from their natural environments into long-term memory, and can discriminate between familiar and unfamiliar items, and between recently seen and new items, very quickly (within 1 sec). They also suggest that infants represent information about not only whether a stimulus is familiar or unfamiliar but also whether it has been seen recently. [source]


    Neural Correlates of Encoding Predict Infants' Memory in the Paired-Comparison Procedure

    INFANCY, Issue 3 2010
    Kelly A. Snyder
    The present study used event-related potentials (ERPs) to monitor infant brain activity during the initial encoding of a previously novel visual stimulus, and examined whether ERP measures of encoding predicted infants' subsequent performance on a visual memory task (i.e., the paired-comparison task). A late slow wave component of the ERP measured at encoding predicted infants' immediate performance in the paired-comparison task: amplitude of the late slow wave at right-central and temporal leads decreased with stimulus repetition, and greater decreases at right-anterior-temporal leads during encoding were associated with better memory performance at test. By contrast, neither the amplitude nor latency of the negative central (Nc) component predicted infants' subsequent performance in the paired-comparison task. These findings are discussed with respect to a biased competition model of visual attention and memory. [source]


    Cortical Indexes of Saccade Planning Following Covert Orienting in 20-Week-Old Infants

    INFANCY, Issue 2 2001
    John E. Richards
    This study examined scalp-recorded, event-related potential (ERP) indexes of saccade planning in 20-week-old infants. A spatial cuing procedure was used in which the infants were presented with a central fixation stimulus and a peripheral cue. A peripheral target followed the cue on the ipsilateral or contralateral side of the cue. The procedure resulted in covert orienting of attention in these participants, reflected in behavioral (e.g., response facilitation or inhibition of return depending on cue-target stimulus-onset asynchrony) and ERP (P1 facilitation to ipsilateral target) indexes of covert orienting of attention. A presaccadic ERP that occurred over the frontal cortex about 50 msec before the saccade onset was largest when the saccade was to a target in a cued location. A presaccadic ERP potential that occurred about 300 msec before the saccade onset was largest for the saccades toward the cued location whether the target was present or not. These results suggest that saccade planning occurs in infants at this age and that infant saccade planning is controlled by cortical systems. [source]


    Understanding the role of managerial agency in achieving business benefits from ERP systems

    INFORMATION SYSTEMS JOURNAL, Issue 3 2010
    Lorraine Staehr
    Abstract Previous enterprise resource planning (ERP) research has identified ,top management support' as an important factor in implementation success. However, most studies are short on the detail of exactly how and why ,top management support' contributes to ERP success. Moreover, although ,improved management decision-making' is often claimed as a business benefit of ERP systems, there is little evidence in previous ERP research of it having actually occurred. This paper examines the role of managerial agency at all levels in four Australian manufacturing organizations in achieving business benefits from ERP systems during the post-implementation period. The research contributes to current understanding of the role of managerial agency in achieving business benefits from ERP systems by providing theoretically based, detailed and interesting insights from four interpretive case studies. [source]


    IT for niche companies: is an ERP system the solution?

    INFORMATION SYSTEMS JOURNAL, Issue 1 2007
    Kai A Olsen
    Abstract., Niche companies are per definition idiosyncratic. They survive in a competitive world by mastering a small market niche, providing what their customers need. This often requires a flexible organization, and the ability to customize products. To be more efficient, many of these companies rely on extensive use of IT, often by installing general Enterprise Resource Planning (ERP) systems. These systems have grown from isolated systems that handle planning based on incoming orders and the component structure of the various products, to systems with ambitions to embrace the total functioning of the company including vendor and customer relation management. In this paper, we present four case studies. One company is a part of a large enterprise, but performs niche functions within this enterprise. The other three are small- or medium-sized enterprises. Each of these performs in small niche markets. Common to all is the fact that they encounter problems with the utilization of their ERP systems. The major problem seems to be that the ERP system has an inherent business model that may not conform to the needs of the company. Without a good understanding of the underlying models and the constraints under which the fundamental algorithms operate, it is difficult to use these systems correctly. Even excellent systems may give bad results if they are applied to situations where they are not suited. Further, the monolithic structure of an ERP system, with a rather complicated parameter setting, is often insufficient to mould the system to the needs of a niche company. We discuss these problems based on our four case studies, and offer alternative approaches that may be considered. [source]


    Relative importance of evaluation criteria for enterprise systems: a conjoint study

    INFORMATION SYSTEMS JOURNAL, Issue 3 2006
    Mark Keil
    Abstract., While a large body of research exists on the development and implementation of software, organizations are increasingly acquiring enterprise software packages [e.g. enterprise resource planning (ERP) systems] instead of custom developing their own software applications. To be competitive in the marketplace, software package development firms must manage the three-pronged trade-off between cost, quality and functionality. Surprisingly, prior research has made little attempt to investigate the characteristics of packaged software that influence management information system (MIS) managers' likelihood of recommending purchase. As a result, both the criteria by which MIS managers evaluate prospective packaged systems and the attributes that lead to commercially competitive ERP software products are poorly understood. This paper examines this understudied issue through a conjoint study. We focus on ERP systems, which are among the largest and most complex packaged systems that are purchased by organizations. In a conjoint study, 1008 evaluation decisions based on hypothetical ERP software package profiles were completed by managers in 126 organizations. The study represents the first empirical investigation of the relative importance that managers ascribe to various factors that are believed to be important in evaluating packaged software. The results provide important insights for both organizations that acquire such systems and those that develop them. The results show that functionality, reliability, cost, ease of use and ease of customization are judged to be important criteria, while ease of implementation and vendor reputation were not found to be significant. Functionality and reliability were found to be the most heavily weighted factors. We conclude the paper with a detailed discussion of the results and their implications for software acquisition and development practice. [source]


    Intangible benefits valuation in ERP projects

    INFORMATION SYSTEMS JOURNAL, Issue 4 2002
    Kenneth E Murphy
    Abstract. The development, implementation and ownership of information systems, especially large-scale systems such as enterprise resource planning (ERP), has become progressively longer in duration and more cost intensive. As a result, IS managers are being required to justify projects financially based on their return. Historically, information systems have been difficult to quantify in monetary terms because of the intangible nature of many of the derived benefits, e.g. improved customer service. Using the case study methodology, this paper examines an attempt by a large computer manufacturer to incorporate intangibles into traditional cost,benefit analysis in an ERP project. The paper reviews the importance of intangibles, lists intangible benefits that are important in ERP projects and demonstrates the use of a scheme through which they can be incorporated into traditional evaluation techniques. [source]