Functional connectivity with medial temporal regions differs across cultures during post-encoding rest.

Connectivity of the brain at rest can reflect individual differences and impact behavioral outcomes, including memory. The present study investigated how culture influences functional connectivity with regions of the medial temporal lobe. In this study, 46 Americans and 59 East Asians completed a resting state scan after encoding pictures of objects. To investigate cross-cultural differences in resting state functional connectivity, left parahippocampal gyrus (anterior and posterior regions) and left hippocampus were selected as seed regions. These regions were selected, because they were previously implicated in a study of cultural differences during the successful encoding of detailed memories. Results revealed that left posterior parahippocampal gyrus had stronger connectivity with temporo-occipital regions for East Asians compared with Americans and stronger connectivity with parieto-occipital regions for Americans compared with East Asians. Left anterior parahippocampal gyrus had stronger connectivity with temporal regions for East Asians than Americans and stronger connectivity with frontal regions for Americans than East Asians. Although connectivity did not relate to memory performance, patterns did relate to cultural values. The degree of independent self-construal and subjective value of tradition were associated with functional connectivity involving left anterior parahippocampal gyrus. Findings are discussed in terms of potential cultural differences in memory consolidation or more general trait or state-based processes, such as holistic versus analytic processing.

Effect of self-imagination on memory for older adults and aMCI patients.

Imagining an event from a personal perspective has been found to be able to enhance memory for words and sentences for healthy younger adults and brain-injured patients. However, little is known about how people with amnestic mild cognitive impairment (aMCI) respond to self-imagination, in comparison to healthy older adults. In the current study, participants were asked to process a group of objects using either a self-imagination approach or a baseline strategy in which the self was not heavily involved. Self-imagination shows a mnemonic advantage over the control strategy, though this pattern emerged more clearly for healthy older adults. Furthermore, suggestive evidence indicates that cognitive ability supports self-reference benefits for healthy older adults, but not aMCI patients. These findings extended previous research to reveal the effectiveness of self-imagination for older adults using pictorial stimuli and supported the viewpoint that aMCI could qualitatively change the way that cognitive resources are engaged.

Spatial-temporal potential exposure risk analytics and urban sustainability impacts related to COVID-19 mitigation: A perspective from car mobility behaviour.

Coronavirus disease-2019 (COVID-19) poses a significant threat to the population and urban sustainability worldwide. The surge mitigation is complicated and associates many factors, including the pandemic status, policy, socioeconomics and resident behaviours. Modelling and analytics with spatial-temporal big urban data are required to assist the mitigation of the pandemic. This study proposes a novel perspective to analyse the spatial-temporal potential exposure risk of residents by capturing human behaviours based on spatial-temporal car park availability data. Near real-time data from 1,904 residential car parks in Singapore, a classical megacity, are collected to analyse car mobility and its spatial-temporal heat map. The implementation of the circuit breaker, a COVID-19 measure, in Singapore has reduced the mobility and heat (daily frequency of mobility) significantly at about 30.0%. It contributes to a 44.3%-55.4% reduction in the transportation-related air emissions under two scenarios of travelling distance reductions. Urban sustainability impacts in both environment and economy are discussed. The spatial-temporal potential exposure risk mapping with space-time interactions is further investigated via an extended Bayesian spatial-temporal regression model. The maximal reduction rate of the defined potential exposure risk lowers to 37.6% by comparison with its peak value. The big data analytics of changes in car mobility behaviour and the resultant potential exposure risks can provide insights to assist in (a) designing a flexible circuit breaker exit strategy, (b) precise management via identifying and tracing hotspots on the mobility heat map, and (c) making timely decisions by fitting curves dynamically in different phases of COVID-19 mitigation. The proposed method has the potential to be used by decision-makers worldwide with available data to make flexible regulations and planning.

The influence of emotional narrative content on the self-reference effect in memory.

This study investigated how emotional language usage impacts self-referential effects in memory in healthy older adults and individuals with amnestic mild cognitive impairment (aMCI). To heighten self-focus, 37 healthy older adults and 22 aMCI participants narrated autobiographical memories and then encoded words using a self-referencing or a semantic strategy. We were interested in how narrating autobiographical memories impacted subsequent memory. We probed narrative language usage with the Linguistic Inquiry and Word Count text analysis program, testing the degree to which language from the narrated autobiographical memories contain emotional (positive and negative) words that predicted the self-reference effect across groups. Results indicated that higher levels of positive emotional language were related to larger self-reference effects in memory. In conclusion, narrating autobiographical memories using emotional language influenced the effectiveness of self-referencing as a memory strategy for both healthy older adults and aMCI participants.

Early dengue outbreak detection modeling based on dengue incidences in Singapore during 2012 to 2017.

Dengue has been as an endemic with year-round presence in Singapore. In the recent years 2013, 2014, and 2016, there were several severe dengue outbreaks, posing serious threat to the public health. To proactively control and mitigate the disease spread, early warnings of dengue outbreaks, at which there are rapid and large-scale spread of dengue incidences, are extremely helpful. In this study, a two-step framework is proposed to predict dengue outbreaks and it is evaluated based on the dengue incidences in Singapore during 2012 to 2017. First, a generalized additive model (GAM) is trained based on the weekly dengue incidence data during 2006 to 2011. The proposed GAM is a one-week-ahead forecasting model, and it inherently accounts for the possible correlation among the historical incidence data, making the residuals approximately normally distributed. Then, an exponentially weighted moving average (EWMA) control chart is proposed to sequentially monitor the weekly residuals during 2012 to 2017. Our investigation shows that the proposed two-step framework is able to give persistent signals at the early stage of the outbreaks in 2013, 2014, and 2016, which provides early alerts of outbreaks and wins time for the early interventions and the preparation of necessary public health resources. In addition, extensive simulations show that the proposed method is comparable to other potential outbreak detection methods and it is robust to the underlying data-generating mechanisms.

Influence of culture and age on the self-reference effect.

Relating information to oneself can enhance memory for young and older adults. However, most studies investigating self-referencing have focused on Western populations, for whom the self is considered an independent and distinct entity. Whether self-referencing as a mnemonic strategy similarly benefits East Asians, cultures associated with interdependent self-construal, has been investigated little, particularly with age. In this study, we investigated the effect of self-reference on memory for both younger and older adults from American and Taiwanese cultures, predicting that self-referencing would be a less effective strategy for younger and older adults from Taiwan compared to Americans. Results reveal some cultural differences with age, with Taiwanese older adults benefitting less from self-referencing than younger Taiwanese, though the effect did not differ with age for Americans, or between younger adults across cultures. Thus, our results suggest that the potential mnemonic benefits of self-referencing may be limited in older adults from Eastern cultures.

Influence of self-referential mode on memory for aMCI patients.

One's concept of the self can act as a schema, in some cases facilitating memory performance but in other cases making memory more prone to errors. In this study, we attempted to induce long-lasting self-reference effects through an autobiographical mode in younger and older adults, as well as patients with amnestic mild cognitive impairment (aMCI), predicting that a self-referential mode of thought would benefit memory. Participants first either recalled autobiographical memories or described three neutral photographs in a narrative condition. This was followed by a conventional self-referencing task. At retrieval, participants completed a recognition task. Contrary to our prediction, the self-referencing benefit emerged consistently under autobiographical and narrative modes across all groups. Although our findings indicate that self-referencing can benefit memory, it carries the risk of increasing false alarm rates when induced through an autobiographical mode and consequently the strategy should be utilized with caution.