Caffeine enhances real-world language processing: evidence from a proofreading task

Caffeine has become the most prevalently consumed psychostimulant in the world, but its influences on daily real-world functioning are relatively unknown. The present work investigated the effects of caffeine (0 mg, 100 mg, 200 mg, 400 mg) on a commonplace language task that required readers to identify and correct 4 error types in extended discourse: simple local errors (misspelling 1- to 2-syllable words), complex local errors (misspelling 3- to 5-syllable words), simple global errors (incorrect homophones), and complex global errors (incorrect subject-verb agreement and verb tense). In 2 placebo-controlled, double-blind studies using repeated-measures designs, we found higher detection and repair rates for complex global errors, asymptoting at 200 mg in low consumers (Experiment 1) and peaking at 400 mg in high consumers (Experiment 2). In both cases, covariate analyses demonstrated that arousal state mediated the relationship between caffeine consumption and the detection and repair of complex global errors. Detection and repair rates for the other 3 error types were not affected by caffeine consumption. Taken together, we demonstrate that caffeine has differential effects on error detection and repair as a function of dose and error type, and this relationship is closely tied to caffeine's effects on subjective arousal state. These results support the notion that central nervous system stimulants may enhance global processing of language-based materials and suggest that such effects may originate in caffeine-related right hemisphere brain processes. Implications for understanding the relationships between caffeine consumption and real-world cognitive functioning are discussed.     

Perceived helpfulness of online consumer reviews: The role of message content and style

The rise of online reviews written by consumers makes possible an examination of how the content and style of these word‐of‐mouth messages contribute to their helpfulness. In this study, consumers are asked to judge the value of real online consumer reviews to their simulated shopping activities. The results suggest the benefits of moderate review length and of positive, but not negative, product evaluative statements. Non‐evaluative product information and information about the reviewer were also found to be associated with review helpfulness. Stylistic elements that may impair clarity (such as spelling and grammatical errors) were associated with less valuable reviews, and elements that may make a review more entertaining (such as expressive slang and humor) were associated with more valuable reviews. These findings point to factors beyond product information that may affect the perceived helpfulness of an online consumer review. Copyright © 2012 John Wiley & Sons, Ltd.     

Up north and down south: Implicit associations between topography and cardinal direction

Route planners show a reliable tendency to select south- relative to north-going routes between two horizontally (east/west) aligned landmarks, suggesting the application of a north-is-up heuristic (Brunyé, Mahoney, Gardony, & Taylor, 2010). The source of this north-is-up bias remains unknown, and there is no strong evidence to suggest that it is due to explicit strategy use. In four experiments, we attempt to further elucidate the source of this effect by testing whether it can be attributed to implicit associations between cardinal direction (north/south) and topography (mountainous/level terrain). Experiments 1 and 2 used an adapted Implicit Association Test and demonstrate automatically activated judgements that associate north with mountainous and south with relatively level terrain. Experiment 3 rules out the possibility that this effect is due to the local topography of New England by replicating in participants from the topographically dissimilar Midwestern United States. Finally, Experiment 4 tests the relative contribution of implicit versus explicit associations between cardinal direction and topography in predicting route-planning asymmetries; we show that implicit associations are a stronger predictor of southern route biases than explicit processes. Overall, results demonstrate that the conceptualization of space can be driven by physically unfounded implicit associations between cardinal directions and topographical features, and these associations are at least partially responsible for southern route preferences.     

Development and Validation of an Instrument for the Assessment of Dependency Among Bereaved Persons

Dependency among bereaved individuals has been hypothesized to be an important predictor of severe and enduring grief reactions. However, although there are a number of instruments that assess interpersonal dependency as a personality trait or style, no scales are available to assess bereavement-related dependency. Data from 170 widowed participants in a community-based longitudinal investigation, who had been bereaved for an average of 10.8 months, were used to investigate the reliability and validity of the Bereavement Dependency Scale (BDS), an instrument that was developed to assess dependency on the deceased among bereaved persons. Results indicated that the BDS demonstrated acceptable internal reliability and satisfactory convergent, discriminant, and construct validity. The BDS may be a clinically useful predictor of enduring and complicated grief reactions, major depressive disorder, and suicidality among recently bereaved individuals.     

The integration of habits maintained by food and water reinforcement through stimulus compounding.

In Experiment 1, a light and a tone were correlated independently with water reinforcement of bar pressing by rats. With different naive subjects in Experiment 2, one of these stimuli was correlated with food and the other with water reinforcement (counterbalanced). In both experiments the absence of tone and light signaled extinction. Tests of stimulus-reinforcer independence in Experiment 2 indicated that tone and light controlled behavior whose rate was specifically affected by deprivation state. In the stimulus-compounding tests of both experiments, response rates were higher to tone-plus-light than to tone or light presented alone (additive summation). This is the first report of additive summation produced through compounding stimuli paired with different reinforcers. The results are discussed in the context of the effects of incentive motivation on operant performance.     

Infant visual fixation: The effect of concentricity,curvilinearity, and number of directions

The goal of the study was to define certain of the effective dimensions of visual stimulation in the infant's visual environment by analyzing the well-documented preference for the bullseye over a pattern of horizontal stripes. The stimuli were ten black and white patterns, including the bullseye and the stripes, designed to vary along three dimensions: concentricity, curvilinearity and number of directions within the stimulus. The dependent measure was total fixation time corrected for position bias. The subects, 18 three-month-old infants, were tested three times each in order to present them with the ten stimuli in all possible combinations with positions reversed.All three dimensions were found to be effective in varying degrees. The results were discussed in terms of underlying mechanisms and the infant's ability to process information from a multidimensional stimulus.     

Software review

Summary Word Works certainly provides a technological approach to creating educational worksheets. These programs ar designed to enhance instructional management and increase student vocabulary efficiently. Educators with at least word processing capability are able to operate this menudriven program.Given that the appropriateness of instructional worksheets is often bantered about the educational community, the contributions of these programs are somewhat limited. Although it is assumed by the software manufacturers that programs as such are motivating for students, the extended use of such activities are often criticized by educational experts. Further, the on-going use of worksheets is tempered by such student variables as student reading ability, students' age-grade level, and other variables.     

Place of Birth, Place of Residence, and Concentration in Social Occupations

To explore the hypothesis that people who migrate across international, provincial, and state borders tend to veer away from occupations that require intense social interaction, demographic data were obtained on 2,638 North Americans who have attained eminence within their chosen fields. Occupations were blind-coded either as "social" or "nonsocial." While there were similar concentrations in social occupations among Native Americans (75.00%) and Native Canadians (73.02%), there were successively fewer social occupations among Canadian emigres (59.53%), world (predominantly European) emigres (51.46%), and Asian emigres (40.99%) to the U.S. Findings suggest that Asian Americans' well-documented tendencies to veer away from lines of work that involve forceful self-expression reflects a continuous variable rather than a dichotomous variable that sharply separates Asian and North American cultures.     

Investigation of a developmental model of risk for depression and suicidality following spousal bereavement

Data from a community-based multi-wave investigation were used to examine a developmental model of risk for depression and suicidality following the death of a spouse. Measures of perceived parental affection and control during childhood were administered to 218 widowed adults 11 months after the death of the spouse. Self-esteem, spousal dependency, depression, and suicidality were assessed 9 months later. Dependency on the deceased spouse mediated a significant association between retrospectively reported parental control during childhood and post-loss depressive symptoms. Depressive symptoms mediated significant associations of dependency on the deceased spouse and low self-esteem with suicidal ideation and behavior.