172 research outputs found
Training executive functions in the laboratory and in real life : cognitive consequences of computer-based exercises and bilingualism
The question of the trainability of executive functions and the impact of such training on related cognitive skills has stirred considerable research interest. Despite a number of studies investigating this, the question has not yet been solved.
The general aim of this thesis was to investigate two very different types of training of executive functions: laboratory-based computerized training (Studies I-III) and realworld training through bilingualism (Studies IV-V). Bilingualism as a kind of training of executive functions is based on the idea that managing two languages requires executive resources, and previous studies have suggested a bilingual advantage in executive functions. Three executive functions were studied in the present thesis: updating of working memory (WM) contents, inhibition of irrelevant information, and shifting between tasks and mental sets.
Studies I-III investigated the effects of computer-based training of WM updating (Study I), inhibition (Study II), and set shifting (Study III) in healthy young adults. All studies showed increased performance on the trained task. More importantly, improvement on an untrained task tapping the trained executive function (near transfer) was seen in Study I and II. None of the three studies showed improvement on untrained tasks tapping some other cognitive function (far transfer) as a result of training. Study I also used PET to investigate the effects of WM updating training on a neurotransmitter closely linked to WM, namely dopamine. The PET results revealed increased striatal dopamine release during WM updating performance as a result of training.
Study IV investigated the ability to inhibit task-irrelevant stimuli in bilinguals and monolinguals by using a dichotic listening task. The results showed that the bilinguals exceeded the monolinguals in inhibiting task-irrelevant information. Study V introduced a new, complementary research approach to study the bilingual executive advantage and its underlying mechanisms. To circumvent the methodological problems related to natural groups design, this approach focuses only on bilinguals and examines whether individual differences in bilingual behavior correlate with executive task performances. Using measures that tap the three above-entioned executive functions, the results suggested that more frequent language switching was associated with better set shifting skills, and earlier acquisition of the second language was related to better inhibition skills.
In conclusion, the present behavioral results showed that computer-based training of executive functions can improve performance on the trained task and on closely related tasks, but does not yield a more general improvement of cognitive skills. Moreover, the functional neuroimaging results reveal that WM training modulates striatal dopaminergic function, speaking for training-induced neural plasticity in this important neurotransmitter system. With regard to bilingualism, the results provide further support to the idea that bilingualism can enhance executive functions. In addition, the new complementary research approach proposed here provides some clues as to which aspects of everyday bilingual behavior may be related to the advantage in executive functions in bilingual individuals
Rumen function in reindeer (Rangifer tarandus tarandus) after sub-maintenance feed intake and subsequent feeding
The aim of this experiment was to ascertain how different feeding strategies affect the rumen function of reindeer after nutritional deprivation. Rumen adaptation to various diets, after restricted feeding, was studied in 44 eight-month-old semi-domesticated female reindeer (Rangifer tarandus tarandus). All animals were initially fed a simulated winter diet based on lichens (lichen diet). A control group, continuously offered the lichen diet ad libitum, was compared to four groups of reindeer that were first restrictively fed (half the ad libitum ration) for eight days followed by one day without feed. The rumen content of restrictively fed animals had higher pH, lower dry matter content and volatile fatty acid (VFA) concentration, a changed composition of VFAs, and lower counts of bacteria compared to that of the control group. The effect was less dramatic than previously reported for reindeer starved for several days. On day 10, the four restrictively fed groups were introduced to different diets. One group was re-fed the lichen diet ad libitum and did not differ from the control group when the experiment ended after five weeks of feeding. Two groups were fed grain-based reindeer feed (pellets) combined with either lichens or grass silage, and one group was fed silage with a gradually increased addition of pellets. Diarrhoea and so called “wet belly” occurred initially in the three latter groups. After five weeks of feeding, the reindeer in the three pellet-fed groups had an altered composition of VFAs and higher counts of protozoa, and also tended to have higher total VFA concentration in the rumen, compared to the control animals and those re-fed the lichen diet. Only small changes were observed in the size of rumen papillae and these could be associated with energy intake. Protozoa decreased over time on the lichen diet. This study confirmed that rumen function was significantly affected by a relatively short period of restricted feed intake. The experiment also revealed a clear difference in rumen function between reindeer adapted to a lichen-based diet and those adjusted to basically grain-based diets. Bacteria that were utilising lichens were drastically reduced when the diet lacked lichens; consequently these bacteria may be regarded as a substrate-specific group.Abstract in Swedish / Sammandrag:Vomfunktionen hos ren (Rangifer tarandus tarandus) efter begränsat födointag och påföljande utfodring Ett försök utfördes med syfte att ta reda på hur olika utfodringsstrategier påverkar vomfunktionerna hos ren (Rangifer t. tarandus) efter en period med lågt näringsintag. Vommens anpassning till olika dieter studerades hos 44 åtta månader gamla honkalvar Alla renarna gavs initialt en simulerad vinterdiet baserad på lav (lavdiet). En kontrollgrupp, som fick äta fritt av lavdieten under hela försöket, jämfördes med fyra grupper renar, som först utfodrades restriktivt med lavdieten (halva fodergivan jämfört med fri utfodring) under åtta dagar och sedan var helt utan foder under en dag. Vominnehåll från de restriktivt utfodrade renarna hade högre pH, lägre torrsubstans, lägre koncentration av flyktiga fettsyror (VFA), förändrad sammansättning av VFA och mindre mängd bakterier än vad som uppmättes i kontrollgruppen. Effekten var inte så dramatisk som den som tidigare rapporterats för renar som svultit flera dagar. Dag 10 sattes de fyra restriktivt utfodrade grupperna på olika dieter. En grupp utfodrades åter med lavdieten i fri mängd, och skiljde sig inte från kontrollgruppen när försöket avslutades efter fem veckors utfodring. Två grupper gavs spannmålsbaserat renfoder (pellets) kombinerat med antingen lav eller ensilage gjort på gräs, och en grupp gavs först enbart ensilage och därefter pellets i gradvis ökande mängd. Flera renar i de tre senare grupperna drabbades av diarré och så kallad ”blöt buk”. Efter fem veckors utfodring hade renarna i de tre pelletsutfodrade grupperna en ändrad sammansättning av VFA och mer protozooer, och tenderade även att ha högre total VFA-koncentration, än de två grupper som fick lavdiet. Endast små förändringar observerades i storleken på vompapiller, och dessa kunde kopplas till energiintag. Protozooerna minskade med tiden på lavdieten. Denna undersökning bekräftar att vomfunktionerna påverkas signifikant av en relativt kort period med minskat födointag. Undersökningen visar också en klar skillnad i vomfunktion mellan renar anpassade till lavdiet och dem som är anpassade till en i huvudsak spannmålsbaserad diet. Bakterier som växte på lav minskade drastiskt när laven uteslöts ur dieten; dessa bakterier kunde följaktligen betraktas som en substrat-specifik grupp
Unwillingness to Engage in Behaviors that Protect Against COVID-19:the Role of Conspiracy Beliefs, Trust, and Endorsement of Complementary and Alternative Medicine
The Relationship of Anxiety and Stress With Working Memory Performance in a Large Non-depressed Sample
Clinical anxiety and acute stress caused by major life events have well-documented detrimental effects on cognitive processes, such as working memory (WM). However, less is known about the relationships of state anxiety or everyday stress with WM performance in non-clinical populations. We investigated the associations between these two factors and three WM composites (verbal WM, visuospatial WM, and n-back updating performance) in a large online sample of non-depressed US American adults. We found a trend for a negative association between WM performance and anxiety, but not with stress. Thus, WM performance appears rather robust against normal variation in anxiety and everyday stress.Peer reviewe
Is Bilingualism Associated With Enhanced Executive Functioning in Adults? A Meta-Analytic Review
This article was published Online First March 1, 2018.
Supplemental materials: http://dx.doi.org/10.1037/bul0000142.suppBecause of enduring experience of managing two languages, bilinguals have been argued to develop superior executive functioning compared with monolinguals. Despite extensive investigation, there is, however, no consensus regarding the existence of such a bilingual advantage. Here we synthesized comparisons of bilinguals’ and monolinguals’ performance in six executive domains using 891 effect sizes from 152 studies on adults. We also included unpublished data, and considered the potential influence of a number of study-, task-, and participant-related variables. Before correcting estimates for observed publication bias, our analyses revealed a very small bilingual advantage for inhibition, shifting, and working memory, but not for monitoring or attention. No evidence for a bilingual advantage remained after correcting for bias. For verbal fluency, our analyses indicated a small bilingual disadvantage, possibly reflecting less exposure for each individual language when using two languages in a balanced manner. Moreover, moderator analyses did not support theoretical presuppositions concerning the bilingual advantage. We conclude that the available evidence does not provide systematic support for the widely held notion that bilingualism is associated with benefits in cognitive control functions in adults.The study was financially supported by Academy of Finland (grant 288880),
Emil Aaltonen Foundation project grant, and University of Helsinki 3-year grants
to Minna Lehtonen. We thank Benny Salo for statistical consultation, and Matti
Laine, Jussi Jylkkä, and the rest of the BrainTrain research group for valuable
discussions
Attitudes towards mandatory vaccination and sanctions for vaccination refusal
Aims:Â Investigating attitudes towards mandatory vaccination and sanctions for vaccination refusal in an area with insufficient vaccination coverage may help health authorities to assess which strategies for increasing vaccination coverage are appropriate. This study examines attitudes to vaccine mandates and asks questions regarding what kinds of sanctions could legitimately result from vaccination refusal. It seeks to find out if people's attitudes towards mandates and towards sanctions for vaccination refusal are related to their attitudes to vaccines and the degree of trust they feel towards health care professionals and health care authorities. The study also discusses how the observed attitudes towards mandates may be related to perceptions of autonomy, responsibility, and equitability.Methods:Â Data collection was carried out in Finland through an online survey in a region with suboptimal vaccine uptake. Statistical analysis was conducted on a sample of 1101 respondents, using confirmatory factor analysis and structural regression analysis.Results:Â Persons hold different views on mandates and sanctions. Importantly, the persons who support vaccination mandates and sanctions for vaccination refusal are to a great degree the same people who have positive attitudes to vaccines and high trust in health care professionals and health authorities.Conclusion:Â Trust is a key factor which has a bearing on people's attitudes towards mandates and sanctions for noncompliance. A focus on the reasons for lack of trust, and on how to enhance trust, is a more feasible long-term way (than mandates) to promote large- scale compliance with childhood vaccine programmes in the studied country context.</p
Trait reactance and trust in doctors as predictors of vaccination behavior, vaccine attitudes, and use of complementary and alternative medicine in parents of young children
ObjectiveThe aim of the present study was to investigate whether anti-vaccination attitudes and behavior, and positive attitudes to complementary and alternative medicine (CAM), are driven by trait reactance and a distrust in medical doctors.MethodsThe sample consisted of 770 Finnish parents who filled out an online survey. Structural equation modeling (SEM) was used to examine if trait reactance plays a role in vaccination decisions, vaccine attitudes, and in the use of CAM, and whether that relationship is mediated by trust in medical doctors.ResultsParents with higher trait reactance had lower trust in doctors, more negative attitudes to vaccines, a higher likelihood of not accepting vaccines for their children and themselves, and a higher likelihood to use CAM treatments that are not included in evidence-based medicine. Our analyses also revealed associations between vaccination behavior and CAM use and vaccine attitudes and CAM use, but there was no support for the previous notion that these associations would be explained by trait reactance and trust in doctors.ConclusionsTaken together, higher trait reactance seems to be relevant for attitudes and behaviors that go against conventional medicine, because trait reactance is connected to a distrust in medical doctors. Our findings also suggest that high trait reactance and low trust in doctors function differently for different people: For some individuals they might be associated with anti-vaccination attitudes and behavior, while for others they might be related to CAM use. We speculate that this is because people differ in what is important to them, leading them to react against different aspects of conventional medicine
Fearing the Disease or the Vaccine:The Case of COVID-19
As studies indicate that people perceive COVID-19 as a threatening disease, the demand for a vaccine against the disease could be expected to be high. Vaccine safety concerns might nevertheless outweigh the perceived disease risks when an individual decides whether or not to accept the vaccine. We investigated the role of perceived risk of COVID-19 (i.e., perceived likelihood of infection, perceived disease severity, and disease-related worry) and perceived safety of a prospective vaccine against COVID-19 in predicting intentions to accept a COVID-19 vaccine. Three Finnish samples were surveyed: 825 parents of small children, 205 individuals living in an area with suboptimal vaccination coverage, and 1325 Facebook users nationwide. As points of reference, we compared the perceptions of COVID-19 to those of influenza and measles. COVID-19 was perceived as a threatening disease—more so than influenza and measles. The strongest predictor of COVID-19 vaccination intentions was trusting the safety of the potential vaccine. Those perceiving COVID-19 as a severe disease were also slightly more intent on taking a COVID-19 vaccine. Informing the public about the safety of a forthcoming COVID-19 vaccine should be the focus for health authorities aiming to achieve a high vaccine uptake
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