Attentional control and engagement with digital technology

Multiple demands comprise the efficiency of attentional control. There is abundant evidence that when an individual attempts two or more attentionally demanding activities at the same time, the allocation of attention to the tasks is limited and performance suffers as a result. Yet, recent technological innovations require many individuals to manage multiple digital technologies simultaneously or to switch attentional control between tasks. The ability to multitask with various digital technologies involves dividing attention, switching between tasks, and keeping track of multiple strands of information in working memory

The efficacy of working memory training in improving crystallized intelligence

Crystallized intelligence (Gc) is thought to reflect skills acquired through knowledge and experience and is related to verbal ability, language development^1^ and academic success^2^. Gc, together with fluid intelligence (Gf), are constructs of general intelligence^3^. While Gc involves learning, knowledge and skills, Gf refers to our ability in tests of problem-solving, pattern matching, and reasoning. Although there is evidence that Gf can be improved through memory training in adults^4^, the efficacy of memory training in improving acquired skills, such as Gc and academic attainment, has yet to be established. Furthermore, evidence of transfer effects from gains made in the trained tasks is sparse^5^. Here we demonstrate improvements in Gc and academic attainment using working memory training. Participants in the Training group displayed superior performance in all measures of cognitive assessments post-training compared to the Control group, who received knowledge-based training. While previous studies have indicated that gains in intelligence are due to improvements in test-taking skills^6^, this study demonstrates that it is possible to improve crystallized skills through working memory training. Considering the fundamental importance of Gc in acquiring and using knowledge and its predictive power for a large variety of intellectual tasks, these findings may be highly relevant to improving educational outcomes in those who are struggling

It is better than you think: fluid intelligence across the lifespan

The growth and decline of fluid intelligence is associated with brain structural changes. For example, development of fluid IQ is associated with cortex thickness during the critical period between 6 to 12 years old. On the other end of the lifespan, poor performance in cognitive functioning is attributed to a decrease of frontal gray matter density in elderly populations. In particular, there is a sharp decline in fluid IQ scores after 65 years of age. There is substantial evidence that working memory and fluid intelligence (Gf) share neural substrates, such as the prefrontal and parietal cortices. However, very little research has examined whether the pattern of growth and decline in working memory mirrors that of fluid intelligence. For example, does the decline of working memory skills in elderly populations mirror fluid intelligence? Is the rate of working memory decline similar to the rate of growth

Working memory: Is it the new IQ?

Working memory, our ability to process and remember information, is linked to a range of cognitive activities from reasoning tasks to verbal comprehension. There is also extensive evidence of the relationship between working memory and learning outcomes. However, some researchers suggest that working memory is simply a proxy for IQ and does not make a unique contribution to learning outcomes. Here we show that children's working memory skills at 5 years of age was the best predictor of reading, spelling, and math outcomes six years later. IQ, in contrast, accounted for a smaller portion of unique variance to reading and math skills, and was not a significant predictor of spelling performance. Our results demonstrate that working memory is not a proxy for IQ, but rather represents a dissociable cognitive skill with unique links to learning outcomes. Critically, we find that working memory at the start of formal education is a more powerful predictor of subsequent academic success than IQ. This result has important implications for education, particularly with respect to developing intervention and training. It appears that we should target our efforts in developing working memory skills in order to see gains in learning

Liar, liar, working memory on fire: Investigating the role of working memory in childhood verbal deception

The aim of the current study was to investigate the role of working memory in verbal deception in children. We presented 6- and 7-year-olds with a temptation resistance paradigm; they played a trivia game and were then given an opportunity to peek at the final answers on the back of a card. Measures of both verbal and visuospatial working memory were included. The good liars performed better on the verbal working memory test in both processing and recall compared with the bad liars. However, there was no difference in visuospatial working scores between good liars and bad liars. This pattern suggests that verbal working memory plays a role in processing and manipulating the multiple pieces of information involved in lie-telling

In Situ Bioremediation through Mulching of Soil Polluted by a Copper–Nickel Smelter

Received for publication September 8, 2000. Bioremediation of a heavy metal–polluted soil was investigated in a 3-yr field experiment by adding mulch to a polluted forest floor. The mulch consisted of a mixture of compost and woodchips. The remediation treatment decreased the toxicity of the soil solution to bacteria as determined by the [3H]-thymidine incorporation technique, that is, by measuring the growth rate of soil bacteria extracted from unpolluted humus after exposing them to soil solution containing heavy metals from the experimental plots. Canonical correlation analysis was performed in order to identify the chemical and microbiological changes in the soil. The pH of the mulched organic layer increased by one unit. The concentration of complexed Cu increased and that of free Cu2+ decreased in the soil solution from the mulch treatment. According to basal respiration and litter decomposition, microbial activity increased during the 3 yr following the remediation treatment. The [3H]-thymidine incorporation technique was also used to study the growth rate and tolerance of bacteria to Cu. The bacterial growth rate increased and the Cu tolerance decreased on the treated plots. The structure of the microbial community, as determined by phospholipid fatty acid (PLFA) analysis, remained unchanged. The results indicate that remediation of the polluted soil had occurred, and that adding a mulch to the forest floor is a suitable method for remediating heavy metal–polluted soil

Acquiring variation in an artificial language: children and adults are sensitive to socially conditioned linguistic variation

Languages exhibit sociolinguistic variation, such that adult native speakers condition the usage of linguistic variants on social context, gender, and ethnicity, among other cues. While the existence of this kind of socially conditioned variation is well-established, less is known about how it is acquired. Studies of naturalistic language use by children provide various examples where children's production of sociolinguistic variants appears to be conditioned on similar factors to adults’ production, but it is difficult to determine whether this reflects knowledge of sociolinguistic conditioning or systematic differences in the input to children from different social groups. Furthermore, artificial language learning experiments have shown that children have a tendency to eliminate variation, a process which could potentially work against their acquisition of sociolinguistic variation. The current study used a semi-artificial language learning paradigm to investigate learning of the sociolinguistic cue of speaker identity in 6-year-olds and adults. Participants were trained and tested on an artificial language where nouns were obligatorily followed by one of two meaningless particles and were produced by one of two speakers (one male, one female). Particle usage was conditioned deterministically on speaker identity (Experiment 1), probabilistically (Experiment 2), or not at all (Experiment 3). Participants were given tests of production and comprehension. In Experiments 1 and 2, both children and adults successfully acquired the speaker identity cue, although the effect was stronger for adults and in Experiment 1. In addition, in all three experiments, there was evidence of regularization in participants' productions, although the type of regularization differed with age: children showed regularization by boosting the frequency of one particle at the expense of the other, while adults regularized by conditioning particle usage on lexical items. Overall, results demonstrate that children and adults are sensitive to speaker identity cues, an ability which is fundamental to tracking sociolinguistic variation, and that children's well-established tendency to regularize does not prevent them from learning sociolinguistically conditioned variation

Does Speciation between Arabidopsis halleri and Arabidopsis lyrata Coincide with Major Changes in a Molecular Target of Adaptation?

Ever since Darwin proposed natural selection as the driving force for the origin of species, the role of adaptive processes in speciation has remained controversial. In particular, a largely unsolved issue is whether key divergent ecological adaptations are associated with speciation events or evolve secondarily within sister species after the split. The plant Arabidopsis halleri is one of the few species able to colonize soils highly enriched in zinc and cadmium. Recent advances in the molecular genetics of adaptation show that the physiology of this derived ecological trait involves copy number expansions of the AhHMA4 gene, for which orthologs are found in single copy in the closely related A. lyrata and the outgroup A. thaliana. To gain insight into the speciation process, we ask whether adaptive molecular changes at this candidate gene were contemporary with important stages of the speciation process. We first inferred the scenario and timescale of speciation by comparing patterns of variation across the genomic backgrounds of A. halleri and A. lyrata. Then, we estimated the timing of the first duplication of AhHMA4 in A. halleri. Our analysis suggests that the historical split between the two species closely coincides with major changes in this molecular target of adaptation in the A. halleri lineage. These results clearly indicate that these changes evolved in A. halleri well before industrial activities fostered the spread of Zn- and Cd-polluted areas, and suggest that adaptive processes related to heavy-metal homeostasis played a major role in the speciation process