822 research outputs found

    Distribution of Ih Channels and their Function in the Stomatogastric Ganglion

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    Generation of rhythmic patterns in the absence of descending commands is an essential and powerful trait of many motor networks. Cyclic rhythmic discharges of motoneurons in repeated motor activities like locomotion, mastication and respiration require underlying circuits of neurons, which are called central pattern generators (CPG). This study examined the possible roles of Ih cation channels in the pyloric network of the stomatogastric nervous system, a rhythmically active network of motoneurons that controls movements of the lobster foregut. Of specific interest were the H-currentïżœs involvement in maintaining firing properties, the distribution of Ih channels within the stomatogastric ganglion, and a potential role for Ih in regulation of synaptic strength. I was able to confirm a homeostatic interaction of Ih with A-type potassium channels, where the over-expression of the IA shal gene after RNA injection evoked a compensatory increase of Ih in different motoneuron types. I observed an additional, non-Ih component of the hyperpolarization activated current, which was more likely to occur in shal-RNA and gfp-RNA injected neurons, compared to untreated neurons. Further, I showed that the homeostatic response of Ih increase is unidirectional; overexpression of the Ih protein PIIH did not lead to an increase of IA. In an immunocytochemical study, I found high concentrations of Ih protein localized in the fine neuropil of the stomatogastric ganglion, an area which is rich in synaptic contacts. Finally, I demonstrate a potential role for Ih in regulating synaptic transmission, for which I found evidence in electrophysiological experiments, where the amplitude of inhibitory postsynaptic potentials decreased with increasing activation of Ih

    Nightmares, chronotype, urbanicity, and personality: an online study

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    Chronotype refers to individual differences in sleep timing (“owls” and “larks”) and “eveningness” has been associated with nightmares. However, it has not been tested as to whether neuroticism mediates this relationship. Urbanicity refers to being raised in an urban region and/or currently living in an urban region and is associated with heightened risk for developing mental disorders, and thus might be related to nightmare frequency and nightmare distress. Overall, 2492 persons (1437 women, 1055 men) completed an online survey between 23 March 2015 and 8 April 2015. The mean age of the sample was 47.75 ± 14.41 years. The findings indicate that the previously reported relationship between chronotype and nightmare frequency was mediated by neuroticism and “morningness” was related to higher dream recall compared to persons with a late bedtime preference. Urbanicity was not related to nightmare frequency but to lower nightmare distress, raising the interesting question as to whether beliefs about nightmares might be an important variable that contributes to nightmare distress. Based on the few studies so far, there are still many unresolved questions about the interaction between nightmares, chronotype, and urbanicity

    Does social desirability compromise self-reports of physical activity in web-based research?

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    <p>Abstract</p> <p>Background</p> <p>This study investigated the relation between social desirability and self-reported physical activity in web-based research.</p> <p>Findings</p> <p>A longitudinal study (<it>N </it>= 5,495, 54% women) was conducted on a representative sample of the Dutch population using the Marlowe-Crowne Scale as social desirability measure and the short form of the International Physical Activity Questionnaire. Social desirability was not associated with self-reported physical activity (in MET-minutes/week), nor with its sub-behaviors (i.e., walking, moderate-intensity activity, vigorous-intensity activity, and sedentary behavior). Socio-demographics (i.e., age, sex, income, and education) did not moderate the effect of social desirability on self-reported physical activity and its sub-behaviors.</p> <p>Conclusions</p> <p>This study does not throw doubt on the usefulness of the Internet as a medium to collect self-reports on physical activity.</p

    Prosocial consequences of interpersonal synchrony: a meta-analysis

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    Abstract. The capacity to establish interpersonal synchrony is fundamental to human beings because it constitutes the basis for social connection and understanding. Interpersonal synchrony refers to instances when the movements or sensations of two or more people overlap in time and form. Recently, the causal influence of interpersonal synchrony on prosociality has been established through experiments. The current meta-analysis is the first to synthesize these isolated and sometimes contradictory experiments. We meta-analyzed 60 published and unpublished experiments that compared an interpersonal synchrony condition with at least one control condition. The results reveal a medium effect of interpersonal synchrony on prosociality with regard to both attitudes and behaviors. Furthermore, experimenter effects and intentionality moderate these effects. We discuss the strengths and limitations of our analysis, as well as its practical implications, and we suggest avenues for future research

    The day-of-invitation effect on participation in web-based studies

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    Several methods have been proposed to promote participation in web-based research. Here, we examine a technique that is available at no cost: Inviting respondents per e-mail on a particular day of the week. We base our reasoning on such a day-of-invitation effect upon theories on variations in mood and work performance over the week. We conducted five experiments with large and heterogeneous samples to find out whether such effects apply for response rate (i.e., visiting the first page of a study) and retention rate (i.e., completing the study) in web-based studies. We found evidence of a small but significant day-of-invitation effect. Response rate is high at the beginning of the workweek and falls to a low on Friday. Exploratory analyses showed that this decline is higher for employed (vs. nonemployed) persons. Effects on retention rate appear to follow a less straightforward pattern. We discuss possible mechanisms that might account for the day-of-invitation effect and recommend inviting participants on Monday or Tuesday. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.3758/s13428-021-01716-0
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