Objectives

Physical and cognitive tasks occur together in many occupations. Previous reviews of combined tasks have mainly focused on their effects in a sports context. This review investigated to which extent combinations (concurrent or alternating) of occupationally relevant physical and cognitive tasks influence responses reflecting biomechanical exposure, stress, fatigue, performance, and well-being.

Methods

We searched Scopus, Pubmed, Cinahl, and Psychinfo for controlled experiments investigating the effects of combinations of occupationally relevant physical and cognitive tasks in participants aged 18 to 70. In total, we identified 12 447 records. We added recent papers that had cited these studies (n = 573) to arrive at a total of 13 020 publications. After screening for relevance, 61 studies remained, of which 57 were classified to be of medium or high quality. Of the 57 studies, 51 addressed concurrent tasks, 5 alternating tasks, and 1 both concurrent and alternating tasks.

Results

Most studies of concurrent physical and cognitive tasks reported negative effects, if numerically small, on indicators of biomechanical exposure, fatigue, and performance, compared to a physical task alone. Results were mixed for stress indicators, and well-being was too little studied to justify any conclusions. Effects depended on the tasks, including their intensity and complexity. Alternating physical and cognitive tasks did not appear to influence outcomes much, compared to having passive breaks in-between physical tasks.

Conclusions

The reviewed evidence indicated that concurrent physical and cognitive work tasks have negative, yet small effects on biomechanical indicators, fatigue and performance, compared to performing the physical task alone, but only if the physical task is intense, and the cognitive task is complex. Alternating between physical and cognitive tasks may have similar effects as breaking up physical tasks by passive breaks, but studies were few. Future studies should address ecologically valid combinations of physical and cognitive tasks, in particular in controlled field studies devoted to the long-term effects of combined work.

Reading, memory, and learning are the cognitive processes in children that are most affected by noise exposure. Field studies of chronic noise exposure with adequate methodological controls and experimental studies of acute noise exposure both come to similar conclusions on how noise affects reading, memory, and learning of written material. The experimental studies also provide insights to the details of the causal link from noise exposure to impaired memory, in particular showing the importance of the immediate cognitive processing in working memory of the material to be read or memorized. It is expected that further advances in research on working memory will become an emerging theoretical perspective in the area of how noise affects children’s cognition. It is also expected that the current research on reading, memory, and learning of written material will be supplemented with more research on how spoken material is cognitively processed by children when exposed to noise. © 2019 Elsevier B.V. All rights reserved.

The acoustic qualities of a room can have a deleterious effect on the quality of speech signals. The acoustic measurement of reverberation time (RT) has shown to impact second language (L2) speech comprehension positively when lower due to release from spectral and temporal masking effects as well as top-down processing factors. This auralization experiment investigated the benefits of better L2 vocabulary and executive function (updating) skills during L2 listening comprehension tests under shorter versus longer RT conditions (0.3 and 0.9 s). 57 bilingual university students undertook L2 vocabulary, number updating and L2 listening comprehension tests. After splitting groups into high/low vocabulary and updating groups, a mixed ANOVA was conducted. The high number updating group showed no significant differences or interactions in L2 listening comprehension than the lower number updating group across RT conditions. The high vocabulary group had 22% better L2 listening comprehension than the low vocabulary group in long RT, and 9% better in short RT. A significant benefit in L2 listening comprehension due to release from reverberation was only evident in the high vocabulary group. Results indicate that the benefit of good room acoustics for listening comprehension is greatest for those with better language (vocabulary) ability.

Fysisk variation i arbetet anses allmänt av både forskare och praktiker att vara en förutsättning för god hälsa. Både för hög och för låg belastning kan med tiden leda till sämre välbefinnande och prestation. Den gällande föreskriften om belastningsergonomi (AFS 2012:2) anger specifikt att problem med repetitivt, styrt och bundet arbete ska förebyggas genom ökad variation, ”till exempel genom arbetsväxling, arbetsutvidgning eller pauser.” Samtidigt visar flera aktuella forskningsöversikter om variation och arbetsrotation att det vetenskapliga stödet för att dessa initiativ verkligen leder till bättre hälsa är otillräckligt. En anledning kan vara att de idéer till ökad variation som studerats har varit ineffektiva, till exempel därför att de arbetsuppgifter man växlat mellan har varit snarlika till sin belastning, eller att man, som i många studier av pauser, endast kunnat intervenera under en mindre del av arbetsdagen av hänsyn till produktionen. En modell för arbetsrotation med potential för att både säkra en hållbar produktion och leda till god fysisk och mental variation skulle kunna vara att kombinera fysiskt belastande arbets-uppgifter med produktiva uppgifter som ställer mentala krav, men inte är fysiskt krävande. Vid Forte-centret har vi under ett antal år arbetat med denna modell ur olika perspektiv.Det här symposiet ger en överblick över vår forskning. Vi kommer att sammanfatta det internationella forskningsläget, både om variation i stort och specifikt om kombinationer av fysiskt och mentalt belastande arbetsuppgifter. Vi kommer även att presentera en ny princip för hur man kan arbeta med belastning, variation och återhämtning: Guldlocks-principen. Vi kommer att visa resultat från våra egna studier av förekomsten av omväx-lande fysiska och mentala arbetsuppgifter i detaljhandel och industri, och vilka mönster av omväxling de anställda föredrar. Vidare kommer vi att gå igenom våra studier av stress och trötthetsutveckling då man kombinerar repetitivt fysiskt arbete med en mental uppgift av olika svårighetsgrader. Sammantaget kommer symposiet att visa både vilken forskning vi och andra bedrivit på området och vilka forskningsbehov som kvarstår för att svara på om en arbetsrotation som kombinerar fysiska och mentala arbetsuppgifter kan vara effektiv, både vad gäller hälsoeffekter och produktion.

The aims of this questionnaire study were to describe the occurrence and desired number of alternations between mental and physical tasks in industrial and non-industrial blue-collar work, and determine to which extent selected personal and occupational factors influence these conditions. On average, the 122 participating workers (55 females) reported to have close to four alternations per day between mental and physical tasks, and to desire more alternations than they actually had. They also expressed a general preference for performing a physical task after a mental task and vice versa. In univariate regression models, the desired change in task alternations was significantly associated with Gender, Age, Occupation, Years with current work tasks, and Perceived job control, while Occupation was the only significant determinant in a multiple regression model including all factors. Our results suggest that alternations between productive physical and mental tasks could be a viable option in future job rotation.

In four recent experiments we have seen that a long reverberation time (RvT) may improve, rather than impair, comprehension and recall of spoken words or texts for participants who have limited language skills. A long RvT improved, rather than impaired, comprehension for Swedish pupils with a low proficiency in English reading when taking a grade 9 English listening comprehension test in their classroom. For those who were good at reading English there was a better recall with a short RvT. This crossover antagonistic interaction was replicated with Swedish college students grouped by their English proficiency reading skills. In two word list experiments with Swedish pupils in grade 4 and college students, English and Swedish words were presented with a long and short RvT and crossed with two signal-to-noise ratios. Also here there were indicators of a crossover interaction to the effects that along reverberation time improved, rather than impaired, the recall of the words for students that were on the low side of English language proficiency. Possible explanations will be discussed in the presentation.

Background. Health and well-being at work is generally assumed to be associated with sufficient physical and mental variation. Job rotation, where workers typically alternate between different physical tasks, is a popular initiative. Controlled experiments suggest that favourable effects are associated with alternations between mental and physical tasks, but little is known about this intervention in real work. The aims of this study were (1) to describe the occurrence of alternations between mental and physical tasks, and (2) to identify key determinants of such alternations.

Method. We developed a questionnaire combining established questions with specific questions about alternations. Workers from two occupations (industrial and non-industrial blue-collar work), in jobs containing both physical and mental tasks, were included in the study. 122 (55 females) out of 293 workers approached at four companies answered the questionnaire.

Results. On average, the workers alternated 3.5 times per day between mental and physical tasks. In the non-industrial companies, workers reported wanting more alternations than they had, while desired and actual alternations did not differ in the industrial companies. This effect of occupation on the difference between the number of alternations wanted and the actual alternations available was significant (p < 0.001). Furthermore, there was a general preference for performing a physical task after a mental task, and vice versa. This main effect of primarily performed task type (i.e. either physical or mental) on preferred subsequent task type was significant (p < 0.001). In a univariate analysis, gender appeared to be a strong determinant of the occurrence of alternations, but the effect was absorbed when adding the occupation variable.

Discussion. Within the studied companies, work offered alternations between mental and physical tasks and there was a preference among workers to alternate between tasks. Occupation rather than gender was a key determinant of the number of alternations reported.

Experimental work has shown better visuospatial working memory (VSWM) in profoundly deaf individuals compared to those with normal hearing. Other data, including the UK Biobank resource shows poorer VSWM in individuals with poorer hearing. Using the same database, the authors investigated VSWM in individuals who reported profound deafness. Included in this study were 112 participants who were profoundly deaf, 1310 with poor hearing and 74,635 with normal hearing. All participants performed a card-pair matching task as a test of VSWM. Although variance in VSWM performance was large among profoundly deaf participants, at group level it was superior to that of participants with both normal and poor hearing. VSWM in adults is related to hearing status but the association is not linear. Future study should investigate the mechanism behind enhanced VSWM in profoundly deaf adults.

Speech perception runs smoothly and automatically when there is silence in the background, but when the speech signal is degraded by background noise or by reverberation, effortful cognitive processing is needed to compensate for the signal distortion. Previous research has typically investigated the effects of signal-to-noise ratio (SNR) and reverberation time in isolation, whilst few have looked at their interaction. In this study, we probed how reverberation time and SNR influence recall of words presented in participants’ first- (L1) and second-language (L2). A total of 72 children (10 years old) participated in this study. The to-be-recalled wordlists were played back with two different reverberation times (0.3 and 1.2 sec) crossed with two different SNRs (+3 dBA and +12 dBA). Children recalled fewer words when the spoken words were presented in L2 in comparison with recall of spoken words presented in L1. Words that were presented with a high SNR (+12 dBA) improved recall compared to a low SNR (+3 dBA). Reverberation time interacted with SNR to the effect that at +12 dB the shorter reverberation time improved recall, but at +3 dB it impaired recall. The effects of the physical sound variables (SNR and reverberation time) did not interact with language.

The purpose of this experiment was to explore whether listening positions (close or distant location from the sound source) in the classroom, and classroom reverberation, influence students’ score on a test for second-language (L2) listening comprehension (i.e., comprehension of English in Swedish speaking participants). The listening comprehension test administered was part of a standardized national test of English used in the Swedish school system. A total of 125 high school pupils, 15 years old, participated. Listening position was manipulated within subjects, classroom reverberation between subjects. The results showed that L2 listening comprehension decreased as distance from the sound source increased. The effect of reverberation was qualified by the participants’ baseline L2 proficiency. A shorter reverberation was beneficial to participants with high L2 proficiency, while the opposite pattern was found among the participants with low L2 proficiency. The results indicate that listening comprehension scores—and hence students’ grade in English—may depend on students’ classroom listening position.