Exploring the effects of COVID-19 restrictions on wellbeing across different styles of lockdown

Countries have instigated different restrictions in response to the COVID-19 pandemic. For instance, nationwide, strict “lockdown” in Scotland was enacted with breaches punishable by law, whereas restrictions in Japan allowed for travel and interaction, with citizens requested rather than required to conform. We explored the impact of these differential strategies on health behaviours and wellbeing. In February 2021, 138 Scottish and 139 Japanese participants reported their demographic information, pandemic-induced health behaviour-change (alcohol consumption, diet, perceived sleep quality, physical activity), negative mood, and perceived social isolation. Scottish participants’ health behaviours were characterised by greater change (typically negative), most likely due to greater lifestyle disruption, whereas Japanese participants’ behaviours were more-stable. Negative changes to health behaviours were typically associated with poorer mental wellbeing and isolation. Interestingly though, Japanese participants reported greater negative mood but not isolation despite the less-restrictive lockdown. Taken together, different lockdown styles led to different changes in health behaviours.

Social isolation during COVID-19 lockdown impairs cognitive function

Studies examining the effect of social isolation on cognitive function typically involve older adults and/or specialist groups (e.g., expeditions). We considered the effects of COVID‐19‐induced social isolation on cognitive function within a representative sample of the general population. We additionally considered how participants ‘shielding’ due to underlying health complications, or living alone, performed. We predicted that performance would be poorest under strictest, most‐isolating conditions. At five timepoints over 13 weeks, participants (N = 342; aged 18–72 years) completed online tasks measuring attention, memory, decision‐making, time‐estimation, and learning. Participants indicated their mood as ‘lockdown’ was eased. Performance typically improved as opportunities for social contact increased. Interactions between participant sub‐groups and timepoint demonstrated that performance was shaped by individuals' social isolation levels. Social isolation is linked to cognitive decline in the absence of ageing covariates. The impact of social isolation on cognitive function should be considered when implementing prolonged pandemic‐related restrictive conditions.

Changes in Diet, Sleep, and Physical Activity Are Associated With Differences in Negative Mood During COVID-19 Lockdown

The United Kingdom and Scottish governments instigated a societal lockdown in response to the COVID-19 pandemic. Subsequently, many experienced substantial lifestyle changes alongside the stresses of potentially catching the virus or experiencing bereavement. Stressful situations and poorer health behaviors (e.g., higher alcohol consumption, unhealthy diet, poorer sleep quality, physical inactivity) are frequently linked to poor mental health. Our objective was to examine changes in health behaviors and their relationship with negative mood during COVID-19 lockdown. We also considered associations between health behaviors and socio-demographic differences and COVID-19-induced changes. 399 participants completed a questionnaire asking about their personal situation and health behaviors during lockdown as well as a negative mood scale. The significance threshold for all analyses was α = 0.05. Poorer diet was linked to more-negative mood, and to changes to working status. Poorer sleep quality was linked with more-negative mood, and with 'shielding' from the virus. Being less physically active was related to more-negative mood and student status, whereas being more physically active was linked to having or suspecting COVID-19 infection within the household. Increased alcohol consumption was linked to living with children, but not to negative mood. Changes to diet, sleep quality, and physical activity related to differences in negative mood during COVID-19 lockdown. This study adds to reports on poor mental health during lockdown and identifies lifestyle restrictions and changes to health behaviors which may, to some extent, be responsible for higher negative mood. Our data suggests that it is advisable to maintain or improve health behaviors during pandemic-associated restrictions.

Disambiguating the ambiguity disadvantage effect: Behavioral and electrophysiological evidence for semantic competition

Semantic ambiguity has been shown to slow comprehension, although it is unclear whether this ambiguity disadvantage is attributable to competition in semantic activation or difficulties in response selection. We tested the two accounts by examining semantic relatedness decisions to homonyms, or words with multiple unrelated meanings (e.g., football/electric fan). Our behavioral results showed that the ambiguity disadvantage arises only when the different meanings of words are of comparable frequency, and are thus activated in parallel. Critically, this effect was observed regardless of response-selection difficulties, both when the different meanings triggered inconsistent responses on related trials (e.g., fan-breeze) and consistent responses on unrelated trials (e.g., fan-snake). Our electrophysiological results confirmed that this effect arises during semantic activation of the ambiguous word, indexed by the N400, not during response selection. Overall, the findings show that ambiguity resolution involves semantic competition and delineate why and when this competition arises. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Exploring the Measurement of Markedness and Its Relationship with Other Linguistic Variables

Antonym pair members can be differentiated by each word’s markedness–that distinction attributable to the presence or absence of features at morphological or semantic levels. Morphologically marked words incorporate their unmarked counterpart with additional morphs (e.g., “unlucky” vs. “lucky”); properties used to determine semantically marked words (e.g., “short” vs. “long”) are less clearly defined. Despite extensive theoretical scrutiny, the lexical properties of markedness have received scant empirical study. The current paper employs an antonym sequencing approach to measure markedness: establishing markedness probabilities for individual words and evaluating their relationship with other lexical properties (e.g., length, frequency, valence). Regression analyses reveal that markedness probability is, as predicted, related to affixation and also strongly related to valence. Our results support the suggestion that antonym sequence is reflected in discourse, and further analysis demonstrates that markedness probabilities, derived from the antonym sequencing task, reflect the ordering of antonyms within natural language. In line with the Pollyanna Hypothesis, we argue that markedness is closely related to valence; language users demonstrate a tendency to present words evaluated positively ahead of those evaluated negatively if given the choice. Future research should consider the relationship of markedness and valence, and the influence of contextual information in determining which member of an antonym pair is marked or unmarked within discourse.

Homogenous indium distribution in InGaN/GaN laser active structure grown by LP-MOCVD on bulk GaN crystal revealed by transmission electron microscopy and x-ray diffraction

We present transmission electron microscopy (TEM) and x-ray quantitative studies of the indium distribution in In(x)Ga(1-x)N/GaN multiple quantum wells (MQWs) with x = 0.1 and 0.18. The quantum wells were grown by low-pressure metalorganic chemical vapour deposition (LP-MOCVD) on a bulk, dislocation-free, mono-crystalline GaN substrate. By using the quantitative TEM methodology the absolute indium concentration was determined from the 0002 lattice fringe images by the strain measurement coupled with finite element (FE) simulations of surface relaxation of the TEM sample. In the x-ray diffraction (XRD) investigation, a new simulation program was applied to monitor the indium content and lateral composition gradients. We found a very high quality of the multiple quantum wells with lateral indium fluctuations no higher than Δx(L) = 0.025. The individual wells have very similar indium concentration and widths over the whole multiple quantum well (MQW) stack. We also show that the formation of 'false clusters' is not a limiting factor in indium distribution measurements. We interpreted the 'false clusters' as small In-rich islands formed on a sample surface during electron-beam exposure.

Piezoelectric field around threading dislocation in GaN determined on the basis of high-resolution transmission electron microscopy image

A new method of determining the piezoelectric field around dislocations from high-resolution transmission electron microscopy images is presented. In order to determine the electrical potential distribution near a dislocation core, we used the distortion field, obtained using the geometrical phase method and the non-linear finite element method. The electrical field distribution was determined taking into account the inhomogeneous strain distribution, finite geometry of the sample and the full couplings between elastic and electrical fields. The results of the calculation for a transmission electron microscopy thin sample are presented.