International comparisons of IQ test norms show differences between nations. In the present study, nonverbal reasoning, processing speed and working memory subtest scores of the US, German, French, Finnish, and Scandinavian (combined Swedish‐Norwegian‐Danish sample) WAIS IV standardization samples were compared. The European samples had higher scores on the reasoning subtests compared to the American sample, corroborating earlier studies. The Finnish and Scandinavian samples had lower processing speed and working memory scores than the American, German, and French samples. Mechanisms that may underlie the observed national IQ profiles include: (1) test‐taking attitudes—in tests that require balancing speed and accuracy of performance Americans may prioritize fast performance while Europeans avoid mistakes; (2) differences between languages in digit articulation times; and (3) educational factors—the European advantage on reasoning subtests may be based on there being better educational systems in Europe as compared to the US.
Purpose: A recent study suggests that transcranial brain targeted light treatment via ear canals may have physiological effects on brain function studied by functional magnetic resonance imaging (fMRI) techniques in humans. We tested the hypothesis that bright light treatment could improve psychomotor speed in professional ice hockey players.Methods: Psychomotor speed tests with audio and visual warning signals were administered to a Finnish National Ice Hockey League team before and after 24 days of transcranial bright light or sham treatment. The treatments were given during seasonal darkness in the Oulu region (latitude 65 degrees north) when the strain on the players was also very high (10 matches during 24 days). A daily 12-min dose of bright light or sham (n = 11 for both) treatment was given every morning between 8 and 12 am at home with a transcranial bright light device. Mean reaction time and motor time were analyzed separately for both psychomotor tests. Analysis of variance for repeated measures adjusted for age was performed.Results: Time × group interaction for motor time with a visual warning signal was p = 0.024 after adjustment for age. In Bonferroni post-hoc analysis, motor time with a visual warning signal decreased in the bright light treatment group from 127 ± 43 to 94 ± 26 ms (p = 0.024) but did not change significantly in the sham group 121 ± 23 vs. 110 ± 32 ms (p = 0.308). Reaction time with a visual signal did not change in either group. Reaction or motor time with an audio warning signal did not change in either the treatment or sham group.Conclusion: Psychomotor speed, particularly motor time with a visual warning signal, improves after transcranial bright light treatment in professional ice-hockey players during the competition season in the dark time of the year.
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