Interference in Working Memory is not Displacement nor Competition - It is Limited Destruction

Free recall of 499 Russian college students was measured using the Tarnow Unchunkable Test (Tarnow, 2014) consisting of sets of 3 and 4 double digit items. Most students can remember 3 items but not 4 items and when the 4th item is added the total recall decreases (Ershova & Tarnow, 2016a). Here we describe the interference that results when adding the fourth item. First, we find that interference affects the items differently, evidence that working memory does not consist of identical “slots”; primacy is found to be an important stabilizer. We model the four item experiment as a superposition of the three item result and a perfectly recalled 1st or 4th item and find that the 4th position is affected 2.5 times as much as is the 1st position. Second, contrary to the displacement/competition theory, recall correlations of the added item with the old items (apparently reported for the first time in a free recall experiment) are typically positive. Third these correlations decay exponentially with item-item presentation distance and are symmetric with respect to time reversal. Small negative recall correlations only appear for subjects with the smallest working memory capacities. Third, also contrary to displacement/competition theory, the fourth item is the least likely to be recalled, thus there is not much need for it to displace the other items. This creates a paradox: while displaying the N+1 item decreases the probability of recall of the N items, actually recalling the N+1 item is positively correlated with recalling the other N items: the N+1 item destroys some of the underlying memory system and then functions as a gauge of its own destruction

A global look at time: a 24-country study of the equivalence of the Zimbardo Time Perspective Inventory

In this article, we assess the structural equivalence of the Zimbardo Time Perspective Inventory (ZTPI) across 26 samples from 24 countries (N = 12,200). The ZTPI is proven to be a valid and reliable index of individual differences in time perspective across five temporal categories: Past Negative, Past Positive, Present Fatalistic, Present Hedonistic, and Future. We obtained evidence for invariance of 36 items (out of 56) and also the five-factor structure of ZTPI across 23 countries. The short ZTPI scales are reliable for country-level analysis, whereas we recommend the use of the full scales for individual-level analysis. The short version of ZTPI will further promote integration of research in the time perspective domain in relation to many different psycho-social processes

Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

Correction to: Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

The original version of this article unfortunately contained a mistake

A Precise Measure of Working Memory Reveals Subjects\ud Difficulties Managing Limited Capacity

Free recall consists of two separate stages: the emptying of working memory and reactivation [1]. The Tarnow Unchunkable Test (TUT, [2]) uses double integer items to separate out only the first stage by making it difficult to reactivate items due to the lack of intra-item relationships. \ud 193 Russian college students were tested via the internet version of the TUT. The average number of items remembered in the 3 item test was 2.54 items. In the 4 item test, the average number of items decreased to 2.38. This, and a number of other qualitative distribution differences between the 3 and 4 item tests, indicates that the average capacity limit of working memory has been reached at 3 items. This provides the first direct measurement of the unchunkable capacity limit of language based items.\ud That the average number of items remembered decreased as the number of items increased from 3 to 4 indicates that most subjects were unable to manage their working memories as the number of items increased just beyond the average capacity. Further evidence for the difficulty in managing the capacity limit is that 25% of subjects could not remember any items correctly at least in one of three 4 item tests and that the Pearson correlation between the 3 item and 4 item subject recalls was a relatively small 38%.\ud This failure of managing a basic memory resource should have important consequences for pedagogy including instruction, text book design and test design. Because working memory scores are important for academic achievement, it also suggests that an individual can gain academically by learning how to manage her or his capacity limit.\u

WORKING MEMORY STRUCTURE REVEALED IN ANALYSIS OF RECALL ERRORS

We analyzed working memory errors stemming from 193 Russian college students taking the Tarnow Unchunkable Test utilizing double digit items on a visual display.In three-item trials with at most one error per trial, single incorrect tens and ones digits (“singlets”) were overrepresented and made up the majority of errors, indicating a base 10 organization.These errors indicate that there are separate memory maps for each position and that there are pointers that can move primarily within these maps. Several pointers make up a pointer collection. The number of pointer collections possible is the working memory capacity limit. A model for self-organizing maps is constructed in which the organization is created by turning common pointer collections into maps thereby replacing a pointer collection with a single pointer.The factors 5 and 11 were underrepresented in the errors, presumably because base 10 properties beyond positional order were used for error correction, perhaps reflecting the existence of additional maps of integers divisible by 5 and integers divisible by 11

Вечное настоящее? От глобальной деревни Маклюэна к искусственному интеллекту

Herbert Marshall McLuhan (1911-1980) was a Canadian philosopher, philologist, literary scholar and media expert. Andy Warhol famously said that in the future everyone will be famous for fifteen minutes. As for McLuhan’s fame, it stretched over decades. His ideas that technology can influence and shape society have been widely discussed up to this day. McLuhan’s work is regarded as an important conceptual contribution to media theory, and his term ‘global village’ is widely used by students and scholars, practitioners and theorists in the field of communication. The authors of this article attempt to analyze the contribution of McLuhan, as a communication expert and influential technodeterminist, to understanding the media of the 21st century. It is concluded that, despite the abundant criticism regarding the naivety and “unscientific” nature of his approach, the lack of empirical evidence for the theory he put forward, his passion for technology, as well as his belief in the decisive role of the media in the development of culture and society, McLuhan’s ideas still inspire researchers. The concept of ‘global village’ in the modern information world has not only retained its relevance - it describes the laws of the functioning of the digital society in the best possible way. The Internet and social networks have confirmed Marshall’s postulate that communication technologies enable people to become increasingly involved in one another’s lives.Маршалл Герберт Маклюэн (1911-1980) - канадский философ, филолог, литературовед и специалист в области медиа. Энди Уорхал однажды сказал, что каждому человеку в жизни выпадает 15 минут славы, слава Маклюэна растянулась на десятилетия. Его идеи о том, что технологии могут влиять на общество и детерминировать его, широко обсуждаются до сих пор. Работы Маклюэна рассматриваются как важный концептуальный вклад в теорию медиа, а его термин «глобальная деревня» (global village) широко используется студентами и учеными, практиками и теоретиками в области коммуникации. В статье предпринимается попытка анализа вклада М. Маклюэна, эксперта по коммуникации, влиятельного технодетерминиста, в понимание медиа XXI в. Делается вывод о том, что, несмотря на обилие критики в адрес наивности, «ненаучности» его подхода, отсутствия эмпирических доказательств выдвинутой им теории, увлеченности технологиями, веры в решающую роль СМИ в развитии культуры и общества, идеи Маклюэна сих пор вдохновляют исследователей. Концепция «глобальной деревни» в современном информационном мире не только не утратила своей актуальности, она как нельзя лучше описывает законы функционирования цифрового общества. Интернет и социальные сети подтвердили постулат Маклюэна, согласно которому коммуникационные технологии предоставляют людям возможность все более активно участвовать в жизни друг друга