Intelligent design
Smarter every day: The deceleration of population ageing in terms of cognition
Valeria Bordone, Sergei Scherbov & Nadia Steiber
Intelligence, September–October 2015, Pages 90–96
Abstract:
Cognitive decline correlates with age-associated health risks and has been shown to be a good predictor of future morbidity and mortality. Cognitive functioning can therefore be considered an important measure of differential ageing across cohorts and population groups. Here, we investigate if and why individuals aged 50+ born into more recent cohorts perform better in terms of cognition than their counterparts of the same age born into earlier cohorts (Flynn effect). Based on two waves of English and German survey data, we show that cognitive test scores of participants aged 50+ in the later wave are higher compared with those of participants aged 50+ in the earlier wave. The mean scores in the later wave correspond to the mean scores in the earlier wave obtained by participants who were on average 4–8 years younger. The use of a repeat cross-sectional design overcomes potential bias from retest effects. We show for the first time that although compositional changes of the older population in terms of education partly explain the Flynn effect, the increasing use of modern technology (i.e., computers and mobile phones) in the first decade of the 2000s also contributes to its explanation.
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Richard Hass & Robert Weisberg
Psychology of Aesthetics, Creativity, and the Arts, forthcoming
Abstract:
Although genius-level creativity is sometimes associated with leaps away from ordinary cognition, evidence suggests otherwise. Here we present analyses of the careers of 5 important composers from the Great American Songbook: Irving Berlin, Jerome Kern, George Gershwin, Cole Porter, and Richard Rodgers. Using those composers as test cases, we evaluated the 10-Year Rule hypothesis for creativity — high-quality creative products emerge only after a long period of immersion within the field. We employed a panel-model approach, an analytic model for cross-sectional, time-series datasets used within the field of econometrics. We found evidence to support the hypothesis in the cases of all 5 composers. More importantly, we showed strong convergent validity between 2 citation indices for composers, 1 compiled from a Web based database, and the other compiled from citations in reference books. We also tested this against a third metric, length of Broadway show run, which also converged. This means that crowd-sourced information and expert opinions on the quality of songs from this era converge, and that both show evidence that composers indeed improved as their careers progressed.
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Ángeles Quiroga et al.
Intelligence, November–December 2015, Pages 1–7
Abstract:
Here we show, for the very first time, that commercial video games can be used to reliably measure individual differences in general intelligence (g). One hundred and eighty eight university undergraduates took part in the study. They played twelve video games under strict supervision in the laboratory and completed eleven intelligence tests. Several factor models were tested for answering the question of whether or not video games and intelligence tests do measure the same underlying high-order latent factor. The final model revealed a very high relationship between the high-order latent factors representing video game and intelligence performance (r = .93). General performance scores derived from video games and intelligence tests showed a correlation value of .963 (R2adjusted). Therefore, performance on some video games captures a latent factor common to the variance shared by cognitive performance assessed by standard ability tests.
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A Common Polymorphism in SCN2A Predicts General Cognitive Ability through Effects on PFC Physiology
Matthew Scult et al.
Journal of Cognitive Neuroscience, September 2015, Pages 1766-1774
Abstract:
Here we provide novel convergent evidence across three independent cohorts of healthy adults (n = 531), demonstrating that a common polymorphism in the gene encoding the α2 subunit of neuronal voltage-gated type II sodium channels (SCN2A) predicts human general cognitive ability or “g.” Using meta-analysis, we demonstrate that the minor T allele of a common polymorphism (rs10174400) in SCN2A is associated with significantly higher “g” independent of gender and age. We further demonstrate using resting-state fMRI data from our discovery cohort (n = 236) that this genetic advantage may be mediated by increased capacity for information processing between the dorsolateral PFC and dorsal ACC, which support higher cognitive functions. Collectively, these findings fill a gap in our understanding of the genetics of general cognitive ability and highlight a specific neural mechanism through which a common polymorphism shapes interindividual variation in “g.”
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A negative Flynn Effect in France, 1999 to 2008–9
Edward Dutton & Richard Lynn
Intelligence, July–August 2015, Pages 67–70
Abstract:
The results of the French WAIS III (1999) and the French WAIS IV (2008–9) are compared based on a sample of 79 subjects aged between 30 years and 63 years who took both tests in 2008–2009. It is shown that between 1999 and 2008–9 the French Full Scale IQ declined by 3.8 points.
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S.L. Spain et al.
Molecular Psychiatry, forthcoming
Abstract:
Although individual differences in intelligence (general cognitive ability) are highly heritable, molecular genetic analyses to date have had limited success in identifying specific loci responsible for its heritability. This study is the first to investigate exome variation in individuals of extremely high intelligence. Under the quantitative genetic model, sampling from the high extreme of the distribution should provide increased power to detect associations. We therefore performed a case–control association analysis with 1409 individuals drawn from the top 0.0003 (IQ >170) of the population distribution of intelligence and 3253 unselected population-based controls. Our analysis focused on putative functional exonic variants assayed on the Illumina HumanExome BeadChip. We did not observe any individual protein-altering variants that are reproducibly associated with extremely high intelligence and within the entire distribution of intelligence. Moreover, no significant associations were found for multiple rare alleles within individual genes. However, analyses using genome-wide similarity between unrelated individuals (genome-wide complex trait analysis) indicate that the genotyped functional protein-altering variation yields a heritability estimate of 17.4% (s.e. 1.7%) based on a liability model. In addition, investigation of nominally significant associations revealed fewer rare alleles associated with extremely high intelligence than would be expected under the null hypothesis. This observation is consistent with the hypothesis that rare functional alleles are more frequently detrimental than beneficial to intelligence.
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Dynamic reconfiguration of frontal brain networks during executive cognition in humans
Urs Braun et al.
Proceedings of the National Academy of Sciences, forthcoming
Abstract:
The brain is an inherently dynamic system, and executive cognition requires dynamically reconfiguring, highly evolving networks of brain regions that interact in complex and transient communication patterns. However, a precise characterization of these reconfiguration processes during cognitive function in humans remains elusive. Here, we use a series of techniques developed in the field of “dynamic network neuroscience” to investigate the dynamics of functional brain networks in 344 healthy subjects during a working-memory challenge (the “n-back” task). In contrast to a control condition, in which dynamic changes in cortical networks were spread evenly across systems, the effortful working-memory condition was characterized by a reconfiguration of frontoparietal and frontotemporal networks. This reconfiguration, which characterizes “network flexibility,” employs transient and heterogeneous connectivity between frontal systems, which we refer to as “integration.” Frontal integration predicted neuropsychological measures requiring working memory and executive cognition, suggesting that dynamic network reconfiguration between frontal systems supports those functions. Our results characterize dynamic reconfiguration of large-scale distributed neural circuits during executive cognition in humans and have implications for understanding impaired cognitive function in disorders affecting connectivity, such as schizophrenia or dementia.
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Clancy Blair et al.
Developmental Psychobiology, forthcoming
Abstract:
Numerous studies demonstrate that the Methionine variant of the catechol-O-methyltransferase Val158Met polymorphism, which confers less efficient catabolism of catecholamines, is associated with increased focal activation of prefrontal cortex (PFC) and higher levels of executive function abilities. By and large, however, studies of COMT Val158Met have been conducted with adult samples and do not account for the context in which development is occurring. Effects of early adversity on stress response physiology and the inverted U shape relating catecholamine levels to neural activity in PFC indicate the need to take into account early experience when considering relations between genes such as COMT and executive cognitive ability. Consistent with this neurobiology, we find in a prospective longitudinal sample of children and families (N = 1292) that COMT Val158Met interacts with early experience to predict executive function abilities in early childhood. Specifically, the Valine variant of the COMT Val158Met polymorphism, which confers more rather than less efficient catabolism of catecholamines is associated with higher executive function abilities at child ages 48 and 60 months and with faster growth of executive function for children experiencing early adversity, as indexed by cumulative risk factors in the home at child ages 7, 15, 24, and 36 months. Findings indicate the importance of the early environment for the relation between catecholamine genes and developmental outcomes and demonstrate that the genetic moderation of environmental risk is detectable in early childhood.