Työmuisti oppimiserojen selittäjänä : näkökulmia työmuistin arvioinnista ja harjoittamisesta

Working memory (WM), a limited cognitive storing and processing mechanism for information, explains individual differences in scholastic learning and, more generally, complex cognition. One dominant view explaining these relationships proposes that variation in WM capacity reflects individual differences in general attentional processes. However, some models propose, that there are also domain-specific aspects in WM that explain variation in cognitive skills. Present series of four studies explored the nature of the mechanisms explaining the close relation between WM and scholastic skills in 5–16-year-old children and adolescents. A total of 1069 subjects participated in the studies. Studies I and II investigated whether the individual differences in the general cognitive capacity are sensitive to external or internal distraction. In Study I the natural environmental noise at the classroom during WM assessment was documented (external distraction). In Study II the complexity of the WM task was manipulated (task’s internal distraction). The contribution of the distraction in the memory scores and in the correlation between WM and scholastic skills was explored. Studies III and IV, in turn, aimed at investigating whether this relationship is causal, that is, whether the training of domain-general WM capacity or domain-specific counting skills, or both, would enhance children's WM and emergent mathematical skills. In two interventions lasting four to five weeks, domains of WM components (verbal WM and short-term memory, STM; visuospatial WM and STM; Study III) and domains of outcome (counting, combined WM and counting; Study IV) were addressed. The results of Studies I and II showed that environmental distraction and task demands contributed the relationship between WM and scholastic skills manifesting the individual differences more clearly. The cognitive constructs assessed appeared to be highly overlapping. However, the results of Studies III and IV indicate that while WM has an important role in scholastic skills, the computerised training of different WM domains did not lead to improvement in numeracy. Despite the lack of such training effects, the group-based interventions addressed to the skill of interest, in this case numeracy, enhanced these skills. Taken together, the present results suggest that while attentional load contributes substantially to individual differences in WM capacity by restricting the mental workspace, the acquired long-term memory representations are needed in order to apply the WM capacity in scholastic learning. The results of the present thesis can be applied in regognising the cognitive deficits that hinders children's scholastic learning, and in developing interventions that benefit scholastic skills.Työmuisti on kapasiteetiltaan ja kestoltaan rajallinen tiedon säilytys- ja prosessointimekanismi. Yksilöllinen vaihtelu työmuistin toiminnassa selittää yksilöiden välisiä eroja kouluoppimisessa ja muissa vaativissa kognitiivisissa eli tiedonkäsittelyn tehtävissä. Yhden vallalla olevan selitysmallin mukaan työmuistin kapasiteetin yksilöllinen vaihtelu heijastaa yksilöiden välisiä eroja yleisissä tarkkaavuuden prosesseissa. Toisten mallien mukaan työmuistiin kuuluu erikoistuneita alayksiköitä ja tiedonkäsittelyn toimintoja, jotka selittävät yksilöiden välisiä eroja kognitiivisissa taidoissa. Tämän väitöskirjatyön neljän osatutkimuksen tavoitteena oli selvittää tarkemmin selittävätkö yleiset vai erikoistuneet työmuistitoiminnot työmuistikapasiteetin ja koulutaitojen yksilöllisen vaihtelun vahvaa yhteyttä 5–16-vuotiailla lapsilla ja nuorilla. Kaikkiaan 1069 koehenkilöä osallistui tutkimuksiin. Osatutkimukset I ja II selvittivät, ovatko yksilölliset erot kognitiivisessa kapasiteetissa herkkiä ulkoiselle tai sisäiselle häiriölle. Ensimmäisessä osatutkimuksessa kirjattiin ulkoisen ympäristön eli luokkahuoneen melu työmuistiarvion aikana (ulkoinen häiriö). Toisessa osatutkimuksessa käytettiin työmuistitehtäviä, joissa oli vaativuustasoltaan erilaiset prosessointiosiot (tehtävän sisäinen häiriö). Ulkoisen ja sisäisen häiriön vaikutuksia tutkittiin toisaalta suhteessa työmuistitehtävässä suoriutumiseen ja toisaalta suhteessa työmuistikapasiteetin ja koulutaitojen välisen yhteyden voimakkuuteen. Osatutkimukset III ja IV sen sijaan pyrkivät selvittämään, onko työmuistikapasiteetin ja koulutaitojen suhde kausaalinen, eli parantaako yleisen työmuistikapasiteetin ja/tai erityisen laskemistaidon harjoitteleminen lasten työmuitikapasiteettia ja varhaisia matemaattisia taitoja. Vaikuttavuustutkimuksissa harjoitettiin tietokoneavusteisesti viiden viikon ajan työmuistin erikoistuneita osa-alueita (kielellinen työmuisti ja lyhytkestoinen muisti; visuospatiaalinen työmuisti ja lyhytkestoinen muisti; Osatutkimus III) sekä ryhmämuotoisesti neljän viikon ajan harjoitettavan taidon kannalta oleellisia taitoja (laskeminen; sekä työmuisti että laskeminen; Osatutkimus IV). Osatutkimusten I ja II tulokset osoittivat, että sekä ympäristön häiriöt että tehtävän vaatimukset vaikuttivat työmuistikapasiteetin ja koulutaitojen välisen suhteen voimakkuuteen siten, että yksilöiden väliset erot tulivat esiin tietyissä ulkoisen ja sisäisen häiriön tilanteissa selvemmin kuin tilanteissa, joissa häiriö oli vähäisempi. Lisäksi arvioitujen kognitiivisten toimintojen havaittiin olevan päällekkäisiä. Osatutkimukset III ja IV puolestaan osoittivat, että vaikka työmuistilla on vahva yhteys koulutaitoihin, työmuistin eri alayksiköiden harjoittaminen ei vahvistanut lasten varhaisia matemaattisia taitoja. Sen sijaan laskemisen harjoittaminen vahvisti lasten varhaisia matemaattisia taitoja. Tämän väitöskirjan tulosten kokonaisuudesta voidaan päätellä, että työmuistin yleisen tarkkaavuusmekanismin kuormittuminen kaventaa mentaalista työtilaa ja on siten merkittävä tekijä yksilöiden välisen kognitiivisen suoriutumisen selittäjänä. Kuitenkin myös aiemmin opittuja tehtäväkohtaisia säilömuistin edustuksia tarvitaan, jotta työmuisti voi toimia tehokkaasti ja edistää näin kouluoppimista. Tutkimustuloksia voidaan hyödyntää lasten kouluoppimisen taustalla olevien ongelmien tunnistamisessa sekä koulutaitoja edistävien harjoitteiden kehittämisessä

Varhaisten matemaattisten taitojen harjoittaminen: matematiikkaspesifiä vai yleistä kognitiivista harjoitusta?

Peer reviewe

Eturauhasen näytepalojen ottamisen jälkeiset tulehdukset

English summaryPeer reviewe

Game-based situation awareness training for child and adult cyclists

Safe cycling requires situation awareness (SA), which is the basis for recognizing and anticipating hazards. Children have poorer SA than adults, which may put them at risk. This study investigates whether cyclists’ SA can be trained with a video- based learning game. The effect of executive working memory on SA was also studied. Thirty-six children (9–10 years) and 22 adults (21–48 years) played the game. The game had 30 video clips filmed from a cyclist’s perspective. Each clip was suddenly masked and two or three locations were presented. The player’s task was to choose locations with a potential hazard and feedback was given for their answers. Working memory capacity (WMC) was tested with a counting span task. Children’s and adults’ performance improved while playing the game, which suggests that playing the game trains SA. Adults performed better than children, and they also glanced at hazards more while the video was playing. Children expectedly had a lower WMC than adults, but WMC did not predict performance within the groups. This indicates that SA does not depend on WMC when passively viewing videos.Peer reviewe

Working memory resources in children: stability and relation to subsequent academic skills

This study aimed to investigate the extent to which WM measured in kindergarten predictsWM measured in second grade (stability of individual WM progress), and the extent to whichWM measured at kindergarten predicts academic performance at second grade (N = 94). Theresults showed that WM skills significantly increase during the time span from Finnishkindergarten to second grade. Verbal (VWM) and visuospatial WM (VSWM) resources seemto develop quite independently, whereas individual progress showed some stability. WMresources measured just before the start of formal school predicted later academicperformance, and VWM acted as more powerful predictor than VSWM resources. The resultshave two important educational implications: first, individual or group-based interventiondesigned to enhance children’s WM skills would be most important even before the start ofschool, and second, poor WM skills should be addressed when planning the learningenvironment beginning in kindergarten.</p

Technical control of nanoparticle emissions from desktop 3D printing

Material extrusion (ME) desktop 3D printing is known to strongly emit nanoparticles (NP), and the need for risk management has been recognized widely. Four different engineering control measures were studied in real-life office conditions by means of online NP measurements and indoor aerosol modeling. The studied engineering control measures were general ventilation, local exhaust ventilation (LEV), retrofitted enclosure, and retrofitted enclosure with LEV. Efficiency between different control measures was compared based on particle number and surface area (SA) concentrations from which SA concentration was found to be more reliable. The study found out that for regular or long-time use of ME desktop 3D printers, the general ventilation is not sufficient control measure for NP emissions. Also, the LEV with canopy hood attached above the 3D printer did not control the emission remarkably and successful position of the hood in relation to the nozzle was found challenging. Retrofitted enclosure attached to the LEV reduced the NP emissions 96% based on SA concentration. Retrofitted enclosure is nearly as efficient as enclosure attached to the LEV (reduction of 89% based on SA concentration) but may be considered more practical solution than enclosure with LEV.Peer reviewe

Neonatal Intestinal Failure Is Independently Associated With Impaired Cognitive Development Later in Childhood

Objective: The impact of pediatric intestinal failure (IF) on neurodevelopment beyond infancy has not been systematically studied. Our aim was to evaluate cognitive and motor impairment and to identify risk factors for adverse outcomes among children with IF. Methods: We conducted a cross-sectional single-center study at the Helsinki University Children's Hospital. Patients with IF with >60 days of parental nutrition (PN) dependency aged between 3 and 16 years (n = 40) were invited to participate. The cognitive and motor skills were evaluated using validated tests: Wechsler Preschool and Primary Scale of Intelligence, 3rd edition, Wechsler Intelligence Scale for Children, 4th edition, and Movement Assessment Battery for Children, 2nd edition. Results: All the patients attending the study tests (n = 30, males = 24) were included. Their median age, gestational age, and birth weight was 7.5 (range 3-16) years, 35 (interquartile range [IQR] 28-38) weeks and 2238 (IQR 1040-3288) grams, respectively. Median duration of PN was 13 (IQR 5-37) months and 9 patients were currently on PN. Median intelligence quotient was 78 (IQR 65-91) and 10 (35%) patients had an intelligence quotient under 70 (-2 standard deviation). Significant motor impairment was detected in 10 patients (36%) and milder difficulties in 8 (28%). Adverse cognitive outcome was associated with neonatal short bowel syndrome, number of interventions under general anesthesia, and length of inpatient status, whereas adverse motor outcome was associated with prematurity. Conclusion: Clinically significant cognitive and motor impairments are alarmingly common among neonatal patients with IF. We recommend early neurodevelopmental follow-up for all children with IF.Peer reviewe

Adaptive Number Knowledge in Secondary School Students: Profiles and Antecedents

The present study aims to examine inter-individual differences in adaptive number knowledge in secondary school students. Adaptive number knowledge is defined as a well-connected network of knowledge of numerical characteristics and arithmetic relations. Substantial and relevant qualitative differences in the strategies and expression of adaptive number knowledge have been found in primary school students still in the process of learning arithmetic. We present a study involving 879 seventh-grade students that examines the structure of individual differences in adaptive number knowledge with students who have completed one year of algebra instruction. Results of a latent profile analysis reveal a model that is similar than was previously found in primary school students. As well, arithmetic fluency and the development of arithmetic fluency are strong predictors of adaptive number knowledge latent profile membership. These results suggest that adaptive number knowledge may be characteristic of high-level performance extending into secondary school, even after formal instruction with arithmetic concludes. </p

Choice Architecture Cueing to Healthier Dietary Choices and Physical Activity at the Workplace:Implementation and Feasibility Evaluation

Redesigning choice environments appears a promising approach to encourage healthier eating and physical activity, but little evidence exists of the feasibility of this approach in real-world settings. The aim of this paper is to portray the implementation and feasibility assessment of a 12-month mixed-methods intervention study, StopDia at Work, targeting the environment of 53 diverse worksites. The intervention was conducted within a type 2 diabetes prevention study, StopDia. We assessed feasibility through the fidelity, facilitators and barriers, and maintenance of implementation, building on implementer interviews (n = 61 informants) and observations of the worksites at six (t1) and twelve months (t2). We analysed quantitative data with Kruskall–Wallis and Mann–Whitney U tests and qualitative data with content analysis. Intervention sites altogether implemented 23 various choice architectural strategies (median 3, range 0–14 strategies/site), employing 21 behaviour change mechanisms. Quantitative analysis found implementation was successful in 66%, imperfect in 25%, and failed in 9% of evaluated cases. These ratings were independent of the ease of implementation of applied strategies and reminders that implementers received. Researchers’ assistance in intervention launch (p = 0.02) and direct contact to intervention sites (p < 0.001) predicted higher fidelity at t1, but not at t2. Qualitative content analysis identified facilitators and barriers related to the organisation, intervention, worksite environment, implementer, and user. Contributors of successful implementation included apt implementers, sufficient implementer training, careful planning, integration into worksite values and activities, and management support. After the study, 49% of the worksites intended to maintain the implementation in some form. Overall, the choice architecture approach seems suitable for workplace health promotion, but a range of practicalities warrant consideration while designing real-world implementation