479 research outputs found

    Integrating across memory episodes: Developmental trends

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    Memory enables us to use information from our past experiences to guide new behaviours, calling for the need to integrate or form inference across multiple distinct episodic experiences. Here, we compared children (aged 9-10 years), adolescents (aged 12-13 years), and young adults (aged 19-25 years) on their ability to form integration across overlapping associations in memory. Participants first encoded a set of overlapping, direct AB- and BC-associations (object-face and face-object pairs) as well as non-overlapping, unique DE-associations. They were then tested on these associations and inferential AC-associations. The experiment consisted of four such encoding/retrieval cycles, each consisting of different stimuli set. For accuracy on both unique and inferential associations, young adults were found to outperform teenagers, who in turn outperformed children. However, children were particularly slower than teenagers and young adults in making judgements during inferential than during unique associations. This suggests that children may rely more on making inferences during retrieval, by first retrieving the direct associations, followed by making the inferential judgement. Furthermore, young adults showed a higher correlation between accuracy in direct (AB, BC) and inferential AC-associations than children. This suggests that, young adults relied closely on AB- and BC-associations for making AC decisions, potentially by forming integrated ABC-triplets during encoding or retrieval. Taken together, our findings suggest that there may be an age-related shift in how information is integrated across experienced episodes, namely from relying on making inferences at retrieval during middle childhood to forming integrated representations at different memory processing stages in adulthood

    Modified p-modes in penumbral filaments?

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    Aims: The primary objective of this study is to search for and identify wave modes within a sunspot penumbra. Methods: Infrared spectropolarimetric time series data are inverted using a model comprising two atmospheric components in each spatial pixel. Fourier phase difference analysis is performed on the line-of-sight velocities retrieved from both components to determine time delays between the velocity signals. In addition, the vertical separation between the signals in the two components is calculated from the Stokes velocity response functions. Results: The inversion yields two atmospheric components, one permeated by a nearly horizontal magnetic field, the other with a less-inclined magnetic field. Time delays between the oscillations in the two components in the frequency range 2.5-4.5 mHz are combined with speeds of atmospheric wave modes to determine wave travel distances. These are compared to expected path lengths obtained from response functions of the observed spectral lines in the different atmospheric components. Fast-mode (i.e., modified p-mode) waves exhibit the best agreement with the observations when propagating toward the sunspot at an angle ~50 degrees to the vertical.Comment: 8 pages, 12 figures, accepted for publication in Astronomy & Astrophysic

    Transport of magnetic flux from the canopy to the internetwork

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    Recent observations have revealed that 8% of linear polarization patches in the internetwork quiet Sun are fully embedded in downflows. These are not easily explained with the typical scenarios for the source of internetwork fields which rely on flux emergence from below. We explore using radiative MHD simulations a scenario where magnetic flux is transported from the magnetic canopy overlying the internetwork into the photosphere by means of downward plumes associated with convective overshoot. We find that if a canopy-like magnetic field is present in the simulation, the transport of flux from the canopy is an important process for seeding the photospheric layers of the internetwork with magnetic field. We propose that this mechanism is relevant for the Sun as well, and it could naturally explain the observed internetwork linear polarization patches entirely embedded in downflows.Comment: Accepted to Ap

    Long‐Term Cognitive Outcome in Anti–N‐Methyl‐D‐Aspartate Receptor Encephalitis

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    Objective: Cognitive dysfunction is a core symptom of anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis, but detailed studies on prevalence, characteristics of cognitive deficits, and the potential for recovery are missing. Here, we performed a prospective longitudinal study to assess cognitive long-term outcome and identify clinical predictors. Methods: Standardized comprehensive neuropsychological assessments were performed in 43 patients with NMDAR encephalitis 2.3 years and 4.9 years (median) after disease onset. Cognitive assessments covered executive function, working memory, verbal/visual episodic memory, attention, subjective complaints, and depression and anxiety levels. Cognitive performance of patients was compared to that of 30 healthy participants matched for age, sex, and education. Results: All patients had persistent cognitive deficits 2.3 years after onset, with moderate or severe impairment in >80% of patients. Core deficits included memory and executive function. After 4.9 years, significant improvement of cognitive function was observed, but moderate to severe deficits persisted in two thirds of patients, despite favorable functional neurological outcomes (median modified Rankin Scale = 1). Delayed treatment, higher disease severity, and longer duration of the acute phase were predictors for impaired cognitive outcome. The recovery process was time dependent, with greater gains earlier after the acute phase, although improvements were possible for several years after disease onset. Interpretation: Cognitive deficits are the main contributor to long-term morbidity in NMDAR encephalitis and persist beyond functional neurological recovery. Nonetheless, cognitive improvement is possible for several years after the acute phase and should be supported by continued cognitive rehabilitation. Cognition should be included as an outcome measure in future clinical studies

    Long‐Term Cognitive Outcome in Anti–N‐Methyl‐D‐Aspartate Receptor Encephalitis

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    Objective Cognitive dysfunction is a core symptom of anti–N‐methyl‐D‐aspartate receptor (NMDAR) encephalitis, but detailed studies on prevalence, characteristics of cognitive deficits, and the potential for recovery are missing. Here, we performed a prospective longitudinal study to assess cognitive long‐term outcome and identify clinical predictors. Methods Standardized comprehensive neuropsychological assessments were performed in 43 patients with NMDAR encephalitis 2.3 years and 4.9 years (median) after disease onset. Cognitive assessments covered executive function, working memory, verbal/visual episodic memory, attention, subjective complaints, and depression and anxiety levels. Cognitive performance of patients was compared to that of 30 healthy participants matched for age, sex, and education. Results All patients had persistent cognitive deficits 2.3 years after onset, with moderate or severe impairment in >80% of patients. Core deficits included memory and executive function. After 4.9 years, significant improvement of cognitive function was observed, but moderate to severe deficits persisted in two thirds of patients, despite favorable functional neurological outcomes (median modified Rankin Scale = 1). Delayed treatment, higher disease severity, and longer duration of the acute phase were predictors for impaired cognitive outcome. The recovery process was time dependent, with greater gains earlier after the acute phase, although improvements were possible for several years after disease onset. Interpretation Cognitive deficits are the main contributor to long‐term morbidity in NMDAR encephalitis and persist beyond functional neurological recovery. Nonetheless, cognitive improvement is possible for several years after the acute phase and should be supported by continued cognitive rehabilitation. Cognition should be included as an outcome measure in future clinical studies. ANN NEUROL 2021;90:949–961Bundesministerium für Bildung und Forschung http://dx.doi.org/10.13039/501100002347Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659Peer Reviewe

    Assessment of breast cancer risk factors reveals subtype heterogeneity

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    Subtype heterogeneity for breast cancer risk factors has been suspected, potentially reflecting etiological differences and implicating risk prediction. Reports are conflicting regarding presence of heterogeneity for many exposures. To examine subtype heterogeneity across known breast cancer risk factors, we conducted a case-control analysis of 2,632 breast cancers and 15,945 controls in Sweden. Molecular subtype was predicted from pathology-record derived immunohistochemistry markers by a classifier trained on PAM50 subtyping. Multinomial logistic regression estimated separate odds ratios for each subtype by the exposures parity, age at first birth, breastfeeding, menarche, HRT use, somatotype at age 18, benign breast disease, mammographic density, polygenic risk score, family history of breast cancer and BRCA mutations. We found clear subtype heterogeneity for genetic factors and breastfeeding. The polygenic risk score was associated with risk of all subtypes except for the basal-like (p heterogeneity < 0.0001). Parous women who never breastfed were at higher risk of basal-like subtype (OR 4.17; 95% CI 1.89 to 9.21) compared to both nulliparous (reference) and breastfeeding women. Breastfeeding was not associated with risk of HER2-overexpressing type, but protective for all other subtypes. The observed heterogeneity in risk of distinct breast cancer subtypes for germline variants supports heterogeneity in etiology and has implications for their use in risk prediction. The increased risk of basal-like subtype among women who never breastfed merits more research into potential causal mechanisms and confounders.Swedish Research CouncilSwedish Cancer SocietyAccepte
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