The coupling of short sleep duration and high sleep need predicts riskier decision making

Abstract

Objective: To examine how risk-related decision making might be associated with habitual sleep variables, including sleep variability, sleep duration and perceived sleep need in young adults cross-sectionally and longitudinally.

Design: 166 participants completed a 7-day protocol with sleep and risk-related decision-making measures at baseline (T1) and 12 months later (T2).

Results: Habitual short sleep duration (averaging < 6?h nightly) was identified in 11.0% in our sample. After controlling for baseline demographic factors and risk-taking measures, self-reported sleep need at T1 interacted with habitual short sleep in predicting risk taking at follow-up (F_8,139=9.575, adjusted R²=.431, p<.001). T1 greater perceived sleep need predicted more risk taking among short sleepers, but decreased risk taking among normal sleepers at T2. Variable sleep timing was cross-sectionally correlated with making more Risky choices at baseline and fewer Safe choices after loss at follow up.

Conclusions: Young adults with variable sleep timing and those with short sleep duration coupled with high perceived sleep need were more likely to take risks. The moderating effects of perceived sleep need suggest that individual differences may alter the impact of sleep loss and hence should be measured and accounted for in future studies.     

Generalist genes and cognitive abilities in Chinese twins

This study considered how far nonverbal cognitive, language and reading abilities are affected by common genetic influences in a sample of 312 typically developing Chinese twin pairs aged from 3 to 11 years. Children were individually given tasks of Chinese word reading, receptive vocabulary, phonological memory, tone awareness, syllable and rhyme awareness, rapid automatized naming, morphological awareness and orthographic skills, and Raven's Colored Progressive Matrices. Factor analyses on the verbal tasks adjusted for age indicated two factors: Language as the first factor and Reading as the second factor. Univariate genetic analyses indicated that genetic influences were substantial for nonverbal cognitive ability and moderate for language and reading. Multivariate genetic analyses showed that nonverbal cognitive ability, language and reading were influenced by shared genetic origins, although there were specific genetic influences on verbal skills that were distinct from those on nonverbal cognitive ability. This study extends the Generalist Genes Hypothesis to Chinese language and reading skills, suggesting that the general effects of genes could be universal across languages.     

Assessing and Reporting the Accuracy of Position Measurements Made With Optical Tracking Systems

The use of optical tracking systems to record human movement is now widespread. Although such systems are convenient and potentially very accurate, they must be used carefully to ensure good data. This paper describes the procedures of calibration and reconstruction of position data in cartesian coordinates and suggests steps to maximize their accuracy. Procedures are proposed for characterizing the accuracy of measurement throughout the experimental workspace, and open discussion of the issue by the research community is invited.     

Analogical effects in reading Dutch verb forms

Previous research has shown that the production of morphologically complex words in isolation is affected by the properties of morphologically, phonologically, or semantically similar words stored in the mental lexicon. We report five experiments with Dutch speakers that show that reading an inflectional word form in its linguistic context is also affected by analogical sets of formally similar words. Using the self-paced reading technique, we show in Experiments 1-3 that an incorrectly spelled suffix delays readers less if the incorrect spelling is in line with the spelling of verbal suffixes in other inflectional forms of the same verb. In Experiments 4 and 5, our use of the self-paced reading technique shows that formally similar words with different stems affect the reading of incorrect suffixal allomorphs on a given stem. These intra- and interparadigmatic effects in reading may be due to online processes or to the storage of incorrect forms resulting from analogical effects in production.     

Loneliness and relationship dispositions in emerging adults: Gender and culture as moderators

Prior research has provided evidence of the link between loneliness and the number of past sexual partners—suggesting the role of short-term intimate connections as a strategy to fulfill belongingness needs. The current study examined whether increased loneliness was associated with increased tendencies to engage in short-term sexual (sociosexuality) and romantic (emophilia) relationships with a sample of 319 Malaysian emerging adults. We also tested whether these associations varied by gender and cultural orientation. Findings from a cross-sectional survey revealed that lonelier individuals generally reported higher emophilia. The positive association between loneliness and sociosexuality, however, was only present among those who were high in vertical individualism (i.e., socialized to construe themselves as independent and different from others). Gender did not moderate either of these associations. These results suggest that the loneliness-driven short-term connections may be less readily manifested as sexual tendencies in populations that are more sexually conservative. Our findings highlight the importance of considering the role of cultural differences at the individual level in addition to the overall cultural context when examining intimate relationship tendencies.     

Understanding the language of reasoning: Cognitive,linguistic, and developmental influences

Certain linguistic structures imply speakers' beliefs about their utterances. Factuals imply that the speaker's hypothesis matches observed data; counterfactuals suggest that hypotheses and observations differ, and uncertainty implies that unclear observations make many hypotheses tenable. We examined how age(11-and 16-year-olds and college students) and syntactic structure (subordinating conjunctions, cognitive verbs, and verb modifications) affect the ability to specify the hypothetical and observational referents of expressions of factual, counterfactual, and uncertainty beliefs. There was considerable linguistic growth during adolescence. College students outperformed the younger students. Age differences were most pronounced on judging the hypothetical referents of counterfactuals and uncertainty structures. The two precollege groups often misinterpreted counterfactuals and uncertainty structures because they equated hypotheses with observations. They seldom understood that uncertainty meant that more than one hypothesis could account for observations. Verb modifications were easier to interpret than cognitive verbs, and subordinating conjunctions were hardest. Factuals were easier than counterfactuals and uncertainty structures.     

Effects of surface texture and grip force on the discrimination of hand-held loads

In this paper, we report the results from two experiments in which subjects were required to discriminate horizontal load forces applied to a manipulandum held with a precision grip. The roughness (and hence friction) of the grip surfaces and required grip force were manipulated. In the first experiment, subjects were instructed to judge the load while maintaining hand position and not letting the manipulandum slip. It was found that performance was influenced by surface texture; a given load was judged to be greater when the surface texture was smooth than when it was rough. This result is consistent with a previous study based on lifting objects and indicates that the effect of surface texture applies to loads in general and not just to gravitational loads (i.e., weight). To test whether the load acting on a smooth object is judged to be greater because the grip force required to prevent it from slipping is larger, a second experiment was carried out. Subjects used a visual feedback display to maintain the same grip force for smooth and rough manipulandum surfaces. In this case, there was no effect of surface texture on load perception. These results provide evidence that perceived load depends on the grip force used to resist the load. The implications of these results in terms of central and peripheral factors underlying load discrimination are considered.