226 research outputs found
A direct comparison of attentional orienting to spatial and temporal positions in visual working memory
Different visual attributes effectively guide attention to specific items in visual working memory (VWM), ensuring that particularly important memory contents are readily available. Predictable temporal structures contribute to this efficient use of VWM:
items are prospectively prioritized when they are expected to be needed. Occasionally, however, visual events only gain
relevance through their timing after they have passed. We investigated retrospective attentional orienting based on temporal
position by directly comparing it with orienting to spatial locations, which is typically considered the most powerful selection
mechanism. In a colour-change-detection task, in which items appeared sequentially at different locations, symbolic number cues
validly indicated the temporal or spatial location of the upcoming probe item either before encoding (precues; Experiment 1) or
during maintenance (retrocues; Experiments 1–3). Temporal and spatial cues were physically identical and only differed in their
mapping onto either temporal or spatial positions. Predictive cues yielded cueing benefits (i.e., higher accuracy and shorter
reaction times) as compared with neutral cues, with larger benefits for precues than for retrocues. Importantly, spatial and
temporal cueing benefits did not differ. Equivalent retrocueing benefits were also observed across different cue-probe intervals
and irrespective of whether spatial or temporal position was used as retrieval cue, indicating that items were directly bound to
temporal position and not prioritized via a space-based mechanism. These findings show that spatial and temporal properties can
be used equally well to flexibly prioritise representations held in VWM and they highlight the functional similarities of space and
time in VWM.Peer Reviewe
Microsaccade-induced prolongation of saccade latencies depends on microsaccade amplitude
Fixations consist of small movements including microsaccades, i.e., rapid flicks in eye position that replace the retinal image by up to 1 degree of visual angle. Recently, we showed in a delayed-saccade task (1) that the rate of microsaccades decreased in the course of saccade preparation and (2) that microsaccades occurring around the time of a go signal were associated with prolonged saccade latencies (Rolfs et al., 2006). A re-analysis of the same data set revealed a strong dependence of these findings on microsaccade amplitude. First, microsaccade amplitude dropped to a minimum just before the generation of a saccade. Second, the delay of response saccades was a function of microsaccade amplitude: Microsaccades with larger amplitudes were followed by longer response latencies. These finding were predicted by a recently proposed model that attributes microsaccade generation to fixation-related activity in a saccadic motor map that is in competition with the generation of large saccades (Rolfs et al., 2008). We propose, therefore, that microsaccade statistics provide a behavioral correlate of fixation-related activity in the oculomotor system
A comparison of the temporal and spatial properties of trans-saccadic perceptual recalibration and saccadic adaptation
Repeated exposure to a consistent trans-saccadic step in the position of the saccadic target reliably produces a change of saccadic gain, a well-established trans-saccadic motor learning phenomenon known as saccadic adaptation. Trans-saccadic changes can also produce perceptual effects. Specifically, a systematic increase or decrease in the size of the object that is being foveated changes the perceptually equivalent size between fovea and periphery. Previous studies have shown that this recalibration of perceived size can be established within a few dozen trials, persists overnight, and generalizes across hemifields. In the current study, we use a novel adjustment paradigm to characterize both temporally and spatially the learning process that subtends this form of recalibration, and directly compare its properties to those of saccadic adaptation. We observed that sinusoidal oscillations in the amplitude of the trans-saccadic change produce sinusoidal oscillations in the reported peripheral size, with a lag of under 10 trials. This is qualitatively similar to what has been observed in the case of saccadic adaptation. We also tested whether learning is generalized to the mirror location on the opposite hemifield for both size recalibration and saccade adaptation. Here the results were markedly different, showing almost complete generalization for recalibration and no generalization for saccadic adaptation. We conclude that perceptual and visuomotor consequences of trans-saccadic changes rely on learning mechanisms that are distinct but develop on similar time scales
Razgraničenje neizravne namjere i svjesnog nehaja
U radu se obrađuje razgraničenje neizravne namjere i svjesnog
nehaja, koje već generacijama predstavlja jedno od najznačajnijih
spornih pitanja kaznenopravne znanosti. U prvom dijelu rada analiziraju
se konceptualne razlike u shvaćanju pojma krivnje te se izlažu
temeljne odrednice različitih učenja o namjeri i nehaju. Slijedi kritički
prikaz važnijih teorija razgraničenja u njemačkoj i austrijskoj kaznenopravnoj
dogmatici, koji je upotpunjen izlaganjem pojedinih kontroverznih
slučajeva iz njemačke sudske prakse. Završni dio rada bavi se
razgraničenjem u hrvatskom pravu de lege lata, pri čemu se izlaže model
tumačenja kojim se u postojeće pozitivnopravne okvire nastoje inkorporirati
suvremeni teorijski dosezi. Primjenjivost predloženog modela
potom se ispituje na recentnom predmetu iz domaće sudske prakse
Забезпечення розвитку інноваційності промислових підприємств при активізації інтелектуального капіталу суспільства
Проаналізовано стан і умови інноваційної діяльності підприємств в Україні. Досліджено проблеми неефективності державної політики в економічній сфері щодо розвитку інноваційності промислових підприємств. Розроблено пропозиції з удосконалення структури і напрямів діяльності державної політики щодо розвитку інноваційності промислових підприємств при активізації інтелектуального капіталу суспільства.Проанализированы состояние и условия инновационной деятельности предприятий в Украине. Исследованы проблемы неэффективности государственной политики в экономической сфере относительно развития инновационности промышленных предприятий. Разработаны предложения по усовершенствованию структуры и направлений деятельности государственной политики относительно развития инновационности промышленных предприятий при активизации интеллектуального капитала.The state and terms of innovative activity of enterprises in Ukraine are analyzed. Problems of inefficiency of public policy are investigated in an economic sphere in relation to innovativeness development of industrial enterprises. Suggestions for the improvement of structure and directions public policy activity in relation to innovativeness development of the industrial enterprises during activation of the society intellectual capital are worked out
Clinically relevant depressive symptoms in young stroke patients - results of the sifap1 study
BACKGROUND Although post-stroke depression is widely recognized, less is known about depressive symptoms in the acute stage of stroke and especially in young stroke patients. We thus investigated depressive symptoms and their determinants in such a cohort.
METHODS The Stroke in Young Fabry Patients study (sifap1) prospectively recruited a large multinational European cohort (n = 5,023) of patients with a cerebrovascular event aged 18-55. For assessing clinically relevant depressive symptoms (CRDS, defined by a BDI-score ≥18) the self-reporting Beck Depression Inventory (BDI) was obtained on inclusion in the study. Associations with baseline parameters, stroke severity (National Institutes of Health Stroke Scale, NIHSS), and brain MRI findings were analyzed.
RESULTS From the 2007 patients with BDI documentation, 202 (10.1%) had CRDS. CRDS were observed more frequently in women (12.6 vs. 8.2% in men, p < 0.001). Patients with CRDS more often had arterial hypertension, diabetes mellitus, and hyperlipidemia than patients without CRDS (hypertension: 58.0 vs. 47.1%, p = 0.017; diabetes mellitus: 17.9 vs. 8.9%, p < 0.001; hyperlipidemia: 40.5 vs. 32.3%, p = 0.012). In the subgroup of patients with ischemic stroke or TIA (n = 1,832) no significant associations between CRDS and cerebral MRI findings such as the presence of acute infarcts (68.1 vs. 65.8%, p = 0.666), old infarctions (63.4 vs. 62.1%, p = 0.725) or white matter hyper-intensities (51.6 vs. 53.7%, p = 0.520) were found.
CONCLUSION Depressive symptoms were present in 10.1% of young stroke patients in the acute phase, and were related to risk factors but not to imaging findings
Olfactory Performance as an Indicator for Protective Treatment Effects in an Animal Model of Neurodegeneration
Background: Neurodegenerative diseases are often accompanied by olfactory deficits. Here we use a rare neurovisceral lipid storage disorder, Niemann–Pick disease C1 (NPC1), to illustrate disease-specific dynamics of olfactory dysfunction and its reaction upon therapy. Previous findings in a transgenic mouse model (NPC1-/-) showed severe morphological and electrophysiological alterations of the olfactory epithelium (OE) and the olfactory bulb (OB) that ameliorated under therapy with combined 2-hydroxypropyl-ß-cyclodextrin (HPßCD)/allopregnanolone/miglustat or HPßCD alone.Methods: A buried pellet test was conducted to assess olfactory performance. qPCR for olfactory key markers and several olfactory receptors was applied to determine if their expression was changed under treatment conditions. In order to investigate the cell dynamics of the OB, we determined proliferative and apoptotic activities using a bromodeoxyuridine (BrdU) protocol and caspase-3 (cas-3) activity. Further, we performed immunohistochemistry and western blotting for microglia (Iba1), astroglia (GFAP) and tyrosine hydroxylase (TH).Results: The buried pellet test revealed a significant olfactory deterioration in NPC1-/- mice, which reverted to normal levels after treatment. At the OE level, mRNA for olfactory markers showed no changes; the mRNA level of classical olfactory receptor (ORs) was unaltered, that of unique ORs was reduced. In the OB of untreated NPC1-/- mice, BrdU and cas-3 data showed increased proliferation and apoptotic activity, respectively. At the protein level, Iba1 and GFAP in the OB indicated increased microgliosis and astrogliosis, which was prevented by treatment.Conclusion: Due to the unique plasticity especially of peripheral olfactory components the results show a successful treatment in NPC1 condition with respect to normalization of olfaction. Unchanged mRNA levels for olfactory marker protein and distinct olfactory receptors indicate no effects in the OE in NPC1-/- mice. Olfactory deficits are thus likely due to central deficits at the level of the OB. Further studies are needed to examine if olfactory performance can also be changed at a later onset and interrupted treatment of the disease. Taken together, our results demonstrate that olfactory testing in patients with NPC1 may be successfully used as a biomarker during the monitoring of the treatment
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