367 research outputs found
Radical-cation salts of BEDT-TTF with lithium tris(oxalato)metallate(III)
The first radical-cation salts in the extensive family (BEDT-TTF)x[(A)M(C2O4)3]·Guest containing lithium as the counter cation have been synthesized and characterised
Can verbal instruction enhance the recall of an everyday task and promote error-monitoring in people with dementia of the Alzheimer-type?
People with dementia of the Alzheimer-type (DAT) have difficulties with performing everyday tasks and error awareness is poor. Here we investigated whether recall of actions and error monitoring in everyday task performance improved when they instructed another person on how to make tea. In this situation, both visual and motor cues are present, and attention sustained by the requirement to keep instructing. The data were drawn from a longitudinal study recording performance in four participants with DAT, filmed regularly for five years in their own homes, completing three tea-making conditions: performed-recall (they made tea themselves); instructed-recall (they instructed the experimenter on how to make tea); and verbal-recall (they described how to make tea). Accomplishment scores (percentage of task they correctly recalled), errors and error-monitoring were coded. Task accomplishment was comparable in the performed-recall and instructed-recall conditions, but both were significantly better than task accomplishment in the verbal-recall condition. Third person instruction did not improve error-monitoring. This study has implications for everyday task rehabilitation for people with DAT
Spin-stretching modes in anisotropic magnets: spin-wave excitations in the multiferroic Ba2CoGe2O7
We studied spin excitations of the multiferroic Ba2CoGe2O7 in high magnetic
fields up to 33 T. In the electron spin resonance and far infrared absorption
spectra we found several spin excitations beyond the two conventional magnon
modes expected for such a two-sublattice antiferromagnet. We show that a
multi-boson spin-wave theory can capture these unconventional modes, that
include spin-stretching modes associated with an oscillating magnetic dipole
(or only quadrupole) moment. The lack of the inversion symmetry allows these
modes to become electric dipole active. We expect that the spin-stretching
modes can be generally observed in inelastic neutron scattering and light
absorption experiments in a broad class of ordered S > 1/2 spin systems with
strong single-ion anisotropy and/or non-centrosymmetric lattice structure.Comment: 5+4 pages, 3 figures, supplement added, manuscript revise
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Recognition memory and source memory in autism spectrum disorder: A study of the intention superiority and enactments effects
It is well established that neurotypical individuals generally show better memory for actions they have performed than actions they have observed others perform or merely read about, a so-called âenactment effectâ. Strikingly, research has also shown that neurotypical individuals demonstrate superior memory for actions they intend to perform in the future (but have not yet performed), an effect commonly known as the âintention superiority effectâ.
Although the enactment effect has been studied among people with ASD, the current study is the first to investigate the intention superiority effect in this disorder. This is surprising given the potential importance this issue has for general theory development, as well as for clinical practice. As such, this study aimed to assess the intention superiority and enactment effects in twenty-two children with ASD, and 20 IQ/age-matched neurotypical children. The results showed that children with ASD demonstrated not only undiminished enactment effects in recognition and source memory, but also (surprisingly for some theories) typical intention superiority effects. The implications of these results for theory, as well as clinical practice, are discussed
Memory distortions: When suggestions cannot be easily ignored
In the present study, the persistence of personal false memories (FMs) after social feedback that denies their truth was assessed. Participants imitated actions performed by the experimenter (Session 1) and watched a doctored video with performed and critical âfakeâ actions (Session 2), followed by a memory rating and a recognition task. A few days later (Session 3), participants were clearly told that some memories were false and received daily reminders of the correct list of objects/actions before testing their memory again in Session 4. Results of both memory ratings and recognition indicated effective FM implantation. Interestingly, response times for correct rejections were longer for fake than true objects, suggesting participants struggled to ignore false suggestions. Crucial for our aim, Session 4 showed that FM persisted also after the debriefing and repeated presentations of correct list of objects/actions, suggesting that FMs for actions are rather difficult to discard
Recognition memory, self-other source memory, and theory-of-mind in children with autism spectrum disorder.
This study investigated semantic and episodic memory in autism spectrum disorder (ASD), using a task which assessed recognition and self-other source memory. Children with ASD showed undiminished recognition memory but significantly diminished source memory, relative to age- and verbal ability-matched comparison children. Both children with and without ASD showed an âenactment effectâ, demonstrating significantly better recognition and source memory for self-performed actions than other-person-performed actions. Within the comparison group, theory-of-mind (ToM) task performance was significantly correlated with source memory, specifically for other-person-performed actions (after statistically controlling for verbal ability). Within the ASD group, ToM task performance was not significantly correlated with source memory (after controlling for verbal ability). Possible explanations for these relations between source memory and ToM are considered
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Si:P as a laboratory analogue for hydrogen on high magnetic field white dwarf stars
Laboratory spectroscopy of atomic hydrogen in a magnetic flux density of 10 5 T (1 gigagauss), the maximum observed on high-field magnetic white dwarfs, is impossible because practically available fields are about a thousand times less. In this regime, the cyclotron and binding energies become equal. Here we demonstrate Lyman series spectra for phosphorus impurities in silicon up to the equivalent field, which is scaled to 32.8 T by the effective mass and dielectric constant. The spectra reproduce the high-field theory for free hydrogen, with quadratic Zeeman splitting and strong mixing of spherical harmonics. They show the way for experiments on He and H 2 analogues, and for investigation of He 2, a bound molecule predicted under extreme field conditions
Magnetic anisotropy of individually addressed spin states
Controlling magnetic anisotropy is a key requirement for the fundamental understanding of molecular magnetism and is a prerequisite for numerous applications in magnetic storage, spintronics, and all-spin logic devices. In order to address the question of molecular magnetic anisotropy experimentally, we have synthesized single crystals of a molecular spin system containing four antiferromagnetically coupled s=5/2 manganese(II) ions. Using low-temperature cantilever magnetometry, we demonstrate the selective population of the
S=0,1,...,10 spin states upon application of magnetic fields up to 33 T and map the magnetic anisotropy of each of these states. We observe a strong dependence of the shape and size of the magnetic anisotropy on the populated spin states, and, in particular, reveal an anisotropy reversal upon going from the lowest to the highest spin state
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Recall of a live and personally experienced eyewitness event by adults with autism spectrum disorder
The aim of the present study was to (a) extend previous eyewitness research in autism spectrum disorder (ASD) using a live and personally experienced event; (b) examine whether witnesses with ASD demonstrate a facilitative effect in memory for self- over other-performed actions; (c) explore source monitoring abilities by witnesses with ASD in discriminating who performed which actions within the event. Eighteen high-functioning adults with ASD and 18 age- and IQ-matched typical counterparts participated in a live first aid scenario in which they and the experimenter each performed a number of actions. Participants were subsequently interviewed for their memory of the event using a standard interview procedure with free recall followed by questioning. The ASD group recalled just as many correct details as the comparison group from the event overall, however they made more errors. This was the case across both free recall and questioning phases. Both groups showed a self-enactment effect across both interview phases, recalling more actions that they had performed themselves than actions that the experimenter had performed. However, the ASD group were more likely than their typical comparisons to confuse the source of self-performed actions in free recall, but not in questioning, which may indicate executive functioning difficulties with unsupported test procedures. Findings are discussed in terms of their theoretical and practical implications
Understanding, treating, and renaming grandiose delusions : a qualitative study
Background
Grandiose delusions are arguably the most neglected psychotic experience in research.
Objectives
We aimed to discover from patients: whether grandiose delusions have harmful consequences; the psychological mechanisms that maintain them; and what help patients may want from clinical services.
Design
A qualitative interview design was used to explore patientsâ experiences of grandiose delusions.
Method
Fifteen patients with past or present experiences of grandiose delusions who were attending psychiatric services were interviewed. Thematic analysis and grounded theory were used to analyse the data.
Results
Participants reported physical, sexual, social, occupational, and emotional harms from grandiose delusions. All patients described the grandiose belief as highly meaningful: it provided a sense of purpose, belonging, or selfâidentity, or it made sense of unusual or difficult events. The meaning from the belief was not synonymous with extreme superiority or arrogance. The meaning obtained appeared to be a key driver of the persistence of the beliefs. Other maintenance factors were subjectively anomalous experiences (e.g., voices), symptoms of mania, fantasy elaboration, reasoning biases, and immersive behaviours. Participants described insufficient opportunities to talk about their grandiose beliefs and related experiences and were generally positive about the possibility of a psychological therapy.
Conclusions
We conclude that grandiosity is a psychologically rich experience, with a number of maintenance factors that may be amenable to a targeted psychological intervention. Importantly, the term âgrandiose delusionâ is an imprecise description of the experience; we suggest âdelusions of exceptionalityâ may be a credible alternative.
Practitioner points
-Harm from grandiose delusions can occur across multiple domains (including physical, sexual, social, occupational, and emotional) and practitioners should assess accordingly.
-However, grandiose delusions are experienced by patients as highly meaningful: they provide a sense of purpose, belonging, or selfâidentity, or make sense of unusual or difficult events.
-Possible psychological maintenance mechanisms that could be a target for intervention include the meaning of the belief, anomalous experiences, mania, fantasy elaboration, reasoning biases, and immersive behaviours.
-Patients are keen to have the opportunity to access talking therapies for this experience. Taking extra time to talk at times of distress, âgoing the extra mileâ, and listening carefully can help to facilitate trust
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