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101.
To create and sustain high quality youth development programs it is important to understand the challenging situations and dilemmas that emerge in program leaders’ daily work with youth. In this research the experiences of leaders in 12 programs were followed over a 2–9 month period, which led to the identification of 250 dilemma situations. Qualitative analyses identified 5 categories and 12 subcategories of dilemmas that reflected distinct types of considerations (e.g., youth’s personalities, relationships with the community). The analyses also found that the experienced leaders in the study typically responded to these dilemmas in ways that were youth-centered and that balanced multiple considerations. It is argued that researchers need to go beyond identifying features of high quality programs, and more fully examine how effective leaders create and sustain high quality in response to the challenging situations of practice. 相似文献
102.
Wolf-Gero Lange Kathrin Heuer Andrea Reinecke Eni S. Becker Mike Rinck 《Cognition & emotion》2013,27(8):1433-1456
Inhibition of return (IOR) is a phenomenon observed when a target unexpectedly appears in the place of a preceding cue: With long cue–target stimulus onset asynchronies, reaction times are longer than for targets that appear in an alternative location. Cognitive theories of anxiety suppose that the IOR effect diminishes with threatening, biologically relevant cues because these catch and hold attention. To test this hypothesis, we conducted three experiments, in which emotional valence of cues (animals or facial expressions) had no influence on the strength of the IOR effect, neither in an unselected sample of students nor in highly spider-fearful or socially anxious participants. Inhibition of return appears to be a robust effect, blind to cue valence. 相似文献
103.
104.
Gerhard Blickle James A. Meurs Andreas Wihler Christian Ewen Anna Kathrin Peiseler 《International Journal of Selection & Assessment》2014,22(3):272-285
Given the variability in personality's relationship with leadership and the use of personality measures in leader selection and assessment, we examine the joint influence of leader trait inquisitiveness and leader political skill on subordinate perceptions of leader charisma and effectiveness. Findings indicate a positive main effect of political skill on charisma, the positive relationship between inquisitiveness and charisma is moderated by heightened political skill, and charisma mediates the relationship between the inquisitiveness by political skill interaction and perceived effectiveness. The moderated mediation results of our study suggest that organizations should not only select creative and imaginative leaders, but also select those who are politically skilled or provide political skill training. 相似文献
105.
This study examined how positive aspects of caregiving affect adaptation to bereavement among older adults who cared for a family member with dementia. The sample consisted of 217 caregivers who were part of the Resources for Enhancing Alzheimer's Caregiver Health Study. Using pre- and postloss data, hierarchical regressions were carried out to examine the effects of positive aspects of caregiving (caregiving benefit) on postloss depression and grief. Findings show that preloss caregiving benefit was associated with higher levels of postloss depression and grief, even after controlling for caregiver demographic characteristics, contextual factors, and caregiving burden. This effect was particularly strong for the relation between benefit and grief. Results demonstrate the importance of studying both positive and negative aspects of caregiving and their relation to bereavement outcomes. 相似文献
106.
Torsten Schubert Kathrin Finke Petra Redel Steffen Kluckow Hermann Müller Tilo Strobach 《Acta psychologica》2015
Experts with video game experience, in contrast to non-experienced persons, are superior in multiple domains of visual attention. However, it is an open question which basic aspects of attention underlie this superiority. We approached this question using the framework of Theory of Visual Attention (TVA) with tools that allowed us to assess various parameters that are related to different visual attention aspects (e.g., perception threshold, processing speed, visual short-term memory storage capacity, top-down control, spatial distribution of attention) and that are measurable on the same experimental basis. In Experiment 1, we found advantages of video game experts in perception threshold and visual processing speed; the latter being restricted to the lower positions of the used computer display. The observed advantages were not significantly moderated by general person-related characteristics such as personality traits, sensation seeking, intelligence, social anxiety, or health status. Experiment 2 tested a potential causal link between the expert advantages and video game practice with an intervention protocol. It found no effects of action video gaming on perception threshold, visual short-term memory storage capacity, iconic memory storage, top-down control, and spatial distribution of attention after 15 days of training. However, observations of a selected improvement of processing speed at the lower positions of the computer screen after video game training and of retest effects are suggestive for limited possibilities to improve basic aspects of visual attention (TVA) with practice. 相似文献
107.
Temporal-cuing studies show faster responding to stimuli at an attended versus unattended time point. Whether the mechanisms involved in this temporal orienting of attention are located early or late in the processing stream has not been answered unequivocally. To address this question, we measured event-related potentials in two versions of an auditory temporal cuing task: Stimuli at the uncued time point either required a response (Experiment 1) or did not (Experiment 2). In both tasks, attention was oriented to the cued time point, but attention could be selectively focused on the cued time point only in Experiment 2. In both experiments, temporal orienting was associated with a late positivity in the timerange of the P3. An early enhancement in the timerange of the auditory N1 was observed only in Experiment 2. Thus, temporal attention improves auditory processing at early sensory levels only when it can be focused selectively. 相似文献
108.
For group-living animals, it is crucial to distinguish one’s own group members from those of other groups. Studies applying
operant conditioning revealed that monkeys living in relatively small groups are able to recognize their own group members
when tested with photographs of group members and other conspecifics. Employing a simple looking time paradigm, we here show
that Barbary macaques living in two social groups comprising 46 and 57 individuals, respectively, at the enclosure ‘La Forêt
des Singes’ at Rocamadour are able to spontaneously distinguish photographs of members of their own group from those depicting
animals that belong to another group. This ability appears to develop with age, as juveniles did not discriminate between
members of their own group and another group, although they showed generally more interest in the pictures than did adults.
Juveniles frequently displayed picture directed behaviours such as lip-smacking, touching and sniffing in both conditions,
indicating that the stimuli were highly salient to them. In conclusion, it appears that at least adult monkeys are able to
memorize the faces of a large number of individuals. Whether the difference in behaviour is based on individual recognition
of one’s own group members or simply the discrimination based on familiarity remains unresolved. However, both mechanisms
would be sufficient for group membership identification. 相似文献
109.
Summary The present paper investigates the role of abstract structural properties in the programming and execution of movement sequences. Three experiments, using converging methods, demonstrate that the motor system represents the abstract structural properties of movement sequences. The first two experiments show that hierarchical structures over a sequence of tapping movements can be used to prepare the motor program, even if the specific elements of the sequence are still unknown. Experiment 2 also shows that the preliminary programming of structural properties of a movement sequence takes more time than the programming of specific elements ( start elements). Experiment 3 suggests that abstract structural properties can be generalized from a special sequence and that they are transferable to other sequences. Abstract structural properties are assumed to be an important component of generalized motor programs. 相似文献
110.
Sodikdjon A. Kodirov Kathrin Bonni Michael Wehrmeister Beat Lutz 《Learning & memory (Cold Spring Harbor, N.Y.)》2021,28(2):44
The depolarization is also important for the short-term synaptic plasticity, known as depolarization-induced suppression of excitation (DSE). The two major types of neurons and their synapses in the lateral nucleus of amygdala (LA) are prone to plasticity. However, DSE in interneurons has not been reported in amygdala in general and in LA in particular. Therefore, we conducted the patch-clamp experiments with LA interneurons. These neurons were identified by lack of adaptation in firing rate of action potentials. In this study, we show for the first time a transient suppression of neurotransmission at synapses both within the local network and between cortical inputs and interneurons of the LA. The retrograde neurotransmission from GABAergic interneurons were comparable with that of glutamatergic pyramidal cells. That is the axonal terminals of cortical inputs do not posses selectivity toward two neuronal subtypes. However, the DSE of both types of neurons involve an increase in intracellular Ca2+ and the release of endogenous cannabinoids (eCB) and activation of presynaptic CB1 receptors. The magnitude of DSE was significantly higher in interneurons compared with pyramidal cells, though developed with some latency.
…I made experiments on myself and my assistant, using smaller doses, and not repeating them so often… — Clouston 1870The biological actions of endogenous cannabinoids (eCB) occur by binding to the CB1 and CB2 receptors throughout the whole body (Ameri 1999; Pertwee 2006; Hill et al. 2007; Yoshida et al. 2011). The density of CB1 receptors in the amygdala is comparably high in mammals (Herkenham et al. 1990).Amygdala similar to hippocampus is important for memory formation and often studied to elucidate plasticity at cellular level using the classical paradigm of Pavlov that continuously serves as a substrate (Pavlov 1927; Bliss and Lomo 1973; Rogan et al. 1997). The amygdala not only receives, but also sends behavior underlying signals into other regions (Racine et al. 1983; Aggleton and Mishkin 1984). While the role of hippocampus is crucial for memory formation, those associated with many different kinds of emotions are mainly modulated by the amygdala (Bucherelli et al. 2006; Fujii et al. 2020). The memory enabling substrate is a long-term potentiation (LTP) of neurotransmission into the postsynaptic neurons (Rogan et al. 1997; Kodirov et al. 2006).The short-term synaptic plasticity in the form of depolarization-induced suppression of either excitation or inhibition (DSE and DSI) has been reported in several regions of the brain (Alger et al. 1996; Kano et al. 2009; Ivanova and Storozhuk 2011). We have discovered DSE in the lateral amygdala (LA), specifically at cortical inputs into the pyramidal neurons (Kodirov et al. 2010).Despite the extensive studies on DSE and DSI, there are only three papers on interneurons that we are aware of. Two of them describe the presence of these phenomena: One study was carried out on parvalbumin immunoreactive interneurons of the stratum radiatum in the hippocampus (Ali 2007) and another on cerebellar stellate and basket cells (Beierlein and Regehr 2006). However, none of the cortical interneurons exhibited DSI despite the presence of a functional and cannabinoid-sensitive inhibitory inputs (Lemtiri-Chlieh and Levine 2007). The retrograde neurotransmission (Llano et al. 1991) takes place via the release of two natural ligands of endogenous cannabinoids anandamide and 2-arachidonoyl-glycerol (Urbanski et al. 2009). These ligands also suppress the evoked excitatory neurotransmission when applied exogenously in vitro (Ameri et al. 1999; Ameri and Simmet 2000; Lemak et al. 2007).Since DSE in interneurons has not been reported in amygdala and we demonstrated the existence of DSE in pyramidal cells of LA (Kodirov et al. 2010), we then studied the same phenomenon in regard to interneurons; the main question was whether or not does depolarization-induced mobilization of eCBs from the two types of postsynaptic LA neurons cause similar retrograde modulation of cortical inputs? Subsequently, DSE between the presynaptic terminals and interneurons was shown, and we found that its properties are similar to those in pyramidal cells of LA. Our study documents the participation of endogenous cannabinoids of interneurons in DSE. 相似文献