101 research outputs found

    A Large N400 but No BOLD Effect – Comparing Source Activations of Semantic Priming in Simultaneous EEG-fMRI

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    Numerous studies have reported neurophysiological effects of semantic priming in electroencephalography (EEG) and in functional magnetic resonance imaging (fMRI). Because of differing methodological constraints, the comparability of the observed effects remains unclear. To directly compare EEG and fMRI effects and neural sources of semantic priming, we conducted a semantic word-picture priming experiment while measuring EEG and fMRI simultaneously. The visually presented primes were pseudowords, words unrelated to the target, semantically related words and the identical names of the target. Distributed source analysis of the event-related potentials (ERPs) successfully revealed a large effect of semantic prime-target relatedness (the N400 effect), which was driven by activations in a left-temporal source region. However, no significantly differing activations between priming conditions were found in the fMRI data. Our results support the notion that, for joint interpretations of existing EEG and fMRI studies of semantic priming, we need to fully appreciate the respective methodological limitations. Second, they show that simultaneous EEG-fMRI, including ERP source localization, is a feasible and promising methodological advancement for the investigation of higher-cognitive processes. Third, they substantiate the finding that, compared to fMRI, ERPs are often more sensitive to subtle cognitive effects

    Person reference as a trouble source in dysarthric talk-in-interaction

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    This chapter provides an analysis of talk between people with acquired motor speech disorders (dysarthria) and family members. Using conversation analytical principles it focuses on how person references are treated as trouble sources in everyday interaction, how they arise and are collaboratively managed. Following a review of relevant literature we present a detailed examination of person references produced by people with dysarthria in conversation with family members. We will show that person references are vulnerable to becoming trouble sources given their potential ambiguity or relatively weak relationship to immediately prior talk

    Discontinuation of anti-PD-1 antibody therapy in the absence of disease progression or treatment limiting toxicity : clinical outcomes in advanced melanoma

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    Background Programmed cell death protein 1 (PD-1) blocking monoclonal antibodies improve the overall survival of patients with advanced melanoma but the optimal duration of treatment has not been established. Patients and Methods This academic real-world cohort study investigated the outcome of 185 advanced melanoma patients who electively discontinued anti-PD-1 therapy with pembrolizumab (N=167) or nivolumab (N=18) in the absence of disease progression (PD) or treatment limiting toxicity (TLT) at 14 medical centres across Europe and Australia. Results Median time on treatment was 12months (range 0.7-43). The best objective tumour response at the time of treatment discontinuation was complete response (CR) in 117 (63%) patients, partial response (PR) in 44 (24%) patients and stable disease (SD) in 16 (9%) patients; 8 (4%) patients had no evaluable disease (NE). After a median follow-up of 18months (range 0.7-48) after treatment discontinuation, 78% of patients remained free of progression. Median time to progression was 12months (range 2-23). PD was less frequent in patients with CR (14%) compared with patients with PR (32%) and SD (50%). Six out of 19 (32%) patients who were retreated with an anti-PD-1 at the time of PD obtained a new antitumour response. Conclusions In this real-world cohort of advanced melanoma patients discontinuing anti-PD-1 therapy in the absence of TLT or PD, the duration of anti-PD-1 therapy was shorter when compared with clinical trials. In patients obtaining a CR, and being treated for >6months, the risk of relapse after treatment discontinuation was low. Patients achieving a PR or SD as best tumour response were at higher risk for progression after discontinuing therapy, and defining optimal treatment duration in such patients deserves further study. Retreatment with an anti-PD-1 at the time of progression may lead to renewed antitumour activity in some patients. Clinical trial registration NCT02673970 (https://clinicaltrials.gov/ct2/show/NCT02673970?cond=melanoma&cntry=BE&city=Jette&rank=3)Peer reviewe

    DHPR activation underlies SR Ca2+ release induced by osmotic stress in isolated rat skeletal muscle fibers

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    Changes in skeletal muscle volume induce localized sarcoplasmic reticulum (SR) Ca2+ release (LCR) events, which are sustained for many minutes, suggesting a possible signaling role in plasticity or pathology. However, the mechanism by which cell volume influences SR Ca2+ release is uncertain. In the present study, rat flexor digitorum brevis fibers were superfused with isoosmotic Tyrode's solution before exposure to either hyperosmotic (404 mOsm) or hypoosmotic (254 mOsm) solutions, and the effects on cell volume, membrane potential (Em), and intracellular Ca2+ ([Ca2+]i) were determined. To allow comparison with previous studies, solutions were made hyperosmotic by the addition of sugars or divalent cations, or they were made hypoosmotic by reducing [NaCl]o. All hyperosmotic solutions induced a sustained decrease in cell volume, which was accompanied by membrane depolarization (by 14–18 mV; n = 40) and SR Ca2+ release. However, sugar solutions caused a global increase in [Ca2+]i, whereas solutions made hyperosmotic by the addition of divalent cations only induced LCR. Decreasing osmolarity induced an increase in cell volume and a negative shift in Em (by 15.04 ± 1.85 mV; n = 8), whereas [Ca2+]i was unaffected. However, on return to the isoosmotic solution, restoration of cell volume and Em was associated with LCR. Both global and localized SR Ca2+ release were abolished by the dihydropyridine receptor inhibitor nifedipine by sustained depolarization of the sarcolemmal or by the addition of the ryanodine receptor 1 inhibitor tetracaine. Inhibitors of the Na-K-2Cl (NKCC) cotransporter markedly inhibited the depolarization associated with hyperosmotic shrinkage and the associated SR Ca2+ release. These findings suggest (1) that the depolarization that accompanies a decrease in cell volume is the primary event leading to SR Ca2+ release, and (2) that volume-dependent regulation of the NKCC cotransporter contributes to the observed changes in Em. The differing effects of the osmotic agents can be explained by the screening of fixed charges by divalent ions

    Do Not Lose Sleep Over It: Implanted Brain-computer Interface Functionality During Nighttime in Late-stage Amyotrophic Lateral Sclerosis

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    BACKGROUND AND OBJECTIVES: Brain-computer interfaces ( BCIs) hold promise as augmentative and alternative communication technology for people with severe motor and speech impairment (locked-in syndrome) due to neural disease or injury. Although such BCIs should be available 24/7, to enable communication at all times, feasibility of nocturnal BCI use has not been investigated. Here, we addressed this question using data from an individual with amyotrophic lateral sclerosis (ALS) who was implanted with an electrocorticography-based BCI that enabled the generation of click-commands for spelling words and call-caregiver signals. METHODS: We investigated nocturnal dynamics of neural signal features used for BCI control, namely low ( LFB: 10-30Hz) and high frequency band power ( HFB: 65-95Hz). Additionally, we assessed the nocturnal performance of a BCI decoder that was trained on daytime data by quantifying the number of unintentional BCI activations at night. Finally, we developed and implemented a nightmode decoder that allowed the participant to call a caregiver at night, and assessed its performance. RESULTS: Power and variance in HFB and LFB were significantly higher at night than during the day in the majority of the nights, with HFB variance being higher in 88% of nights. Daytime decoders caused 245 unintended selection-clicks and 13 unintended caregiver-calls per hour when applied to night data. The developed nightmode decoder functioned error-free in 79% of nights over a period of ±1.5 years, allowing the user to reliably call the caregiver, with unintended activations occurring only once every 12 nights. DISCUSSION: Reliable nighttime use of a BCI requires decoders that are adjusted to sleep-related signal changes. This demonstration of a reliable BCI nightmode and its long-term use by an individual with advanced ALS underscores the importance of 24/7 BCI reliability. TRIAL REGISTRATION: This trial is registered in clinicaltrials.gov under number NCT02224469 (https://clinicaltrials.gov/study/NCT02224469?term=NCT02224469&rank=1). Date of submission to registry: August 21, 2014. Enrollment of first participant: September 7, 2015

    A global experience‐sampling method study of well‐being during times of crisis: The CoCo project

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    We present a global experience-sampling method (ESM) study aimed at describing, predicting, and understanding individual differences in well-being during times of crisis such as the COVID-19 pandemic. This international ESM study is a collaborative effort of over 60 interdisciplinary researchers from around the world in the “Coping with Corona” (CoCo) project. The study comprises trait-, state-, and daily-level data of 7490 participants from over 20 countries (total ESM measurements = 207,263; total daily measurements = 73,295) collected between October 2021 and August 2022. We provide a brief overview of the theoretical background and aims of the study, present the applied methods (including a description of the study design, data collection procedures, data cleaning, and final sample), and discuss exemplary research questions to which these data can be applied. We end by inviting collaborations on the CoCo dataset

    A global experience-sampling method study of well-being during times of crisis : the CoCo project

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    [Corrections added on 5 July 2023 after first online publication: The authorship footnote has been modified on page 1 and the duplicate phrase “experience sampling” has been removed on page 2.]We present a global experience-sampling method (ESM) study aimed at describing, predicting, and understanding individual differences in well-being during times of crisis such as the COVID-19 pandemic. This international ESM study is a collaborative effort of over 60 interdisciplinary researchers from around the world in the “Coping with Corona” (CoCo) project. The study comprises trait-, state-, and daily-level data of 7490 participants from over 20 countries (total ESM measurements = 207,263; total daily measurements = 73,295) collected between October 2021 and August 2022. We provide a brief overview of the theoretical background and aims of the study, present the applied methods (including a description of the study design, data collection procedures, data cleaning, and final sample), and discuss exemplary research questions to which these data can be applied. We end by inviting collaborations on the CoCo dataset.Deutsche Forschungsgemeinschaft.https://wileyonlinelibrary.com/journal/spc3am2024PsychologySDG-03:Good heatlh and well-bein

    Does sadness impair color perception? Flawed evidence and faulty methods.

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    In their 2015 paper, Thorstenson, Pazda, and Elliot offered evidence from two experiments that perception of colors on the blue-yellow axis was impaired if the participants had watched a sad movie clip, compared to participants who watched clips designed to induce a happy or neutral mood. Subsequently, these authors retracted their article, citing a mistake in their statistical analyses and a problem with the data in one of their experiments. Here, we discuss a number of other methodological problems with Thorstenson et al.'s experimental design, and also demonstrate that the problems with the data go beyond what these authors reported. We conclude that repeating one of the two experiments, with the minor revisions proposed by Thorstenson et al., will not be sufficient to address the problems with this work
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