To read or not to read: A meta-analysis of print exposure from infancy to early adulthood.

This research synthesis examines whether the association between print exposure and components of reading grows stronger across development. We meta-analyzed 99 studies (N = 7,669) that focused on leisure time reading of (a) preschoolers and kindergartners, (b) children attending Grades 1–12, and (c) college and university students. For all measures in the outcome domains of reading comprehension and technical reading and spelling, moderate to strong correlations with print exposure were found. The outcomes support an upward spiral of causality: Children who are more proficient in comprehension and technical reading and spelling skills read more; because of more print exposure, their comprehension and technical reading and spelling skills improved more with each year of education. For example, in preschool and kindergarten print exposure explained 12% of the variance in oral language skills, in primary school 13%, in middle school 19%, in high school 30%, and in college and university 34%. Moderate associations of print exposure with academic achievement indicate that frequent readers are more successful students. Interestingly, poor readers also appear to benefit from independent leisure time reading. We conclude that shared book reading to preconventional readers may be part of a continuum of out-of-school reading experiences that facilitate children's language, reading, and spelling achievement throughout their development. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Early reading acquisition and its relation to reading experience and ability 10 years later.

A group of 1st-graders who were administered a battery of reading tasks in a previous study were followed up as 11th graders. Ten years later, they were administered measures of exposure to print, reading comprehension, vocabulary, and general knowledge. First-grade reading ability was a strong predictor of all of the 11th-grade outcomes and remained so even when measures of cognitive ability were partialed out. First-grade reading ability (as well as 3rd- and 5th-grade ability) was reliably linked to exposure to print, as assessed in the 11th grade, even after 11th-grade reading comprehension ability was partialed out, indicating that the rapid acquisition of reading ability might well help develop the lifetime habit of reading, irrespective of the ultimate level of reading comprehension ability that the individual attains. Finally, individual differences in exposure to print were found to predict differences in the growth in reading comprehension ability throughout the elementary grades and thereafter. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Heavy metals in human hair and teeth: the correlation with metal concentration in the environment

We introduce a new method, activity diaries, in order to evaluate human water contact among fishing communities in an area moderately endemic for Schistosoma japonicum in the Dongting Lake region of Southern China. Two hundred and forty-nine subjects (76% male) were followed prospectively over a 9-month-period in order to verify exposure and reinfection. Exposure was determined crudely with questionnaires, direct 12-h water observations, and more precisely with activity diaries and an adjusted exposure model which took into account the time of day, the duration of contact and the percent body surface area in contact with water. Cohort subjects filled in activity diaries for an average of 85 days as compared with 2 days for the direct water observations. The typical unadjusted mean daily water contact (duration) based on the activity diaries was 53 min with 62% of this time spent in fishing. In contrast, the direct water observations revealed an average daily duration of 149 min with 53% of the time spent in fishing. Human water contact patterns (min/day) by site, activity and body part exposed were examined with the activity diaries. Individuals in the 36-49-year-old age range had the highest degree of water contact. Most of this daily contact occurred by males on the hands (mean+/-S.D.; 83.53+/-67.80 min/day) while fishing (mean+/-S.D.; 87.84+/-8.88 min/day) on the lake (mean+/-S.D.; 85.98+/-69.90 min/day). There was a strong positive log correlation (r=0.95) between the crude and adjusted (based on our derived exposure model) diary outcomes for the entire study sample, however, at higher exposure levels this relationship was differentially weaker (r=0.70). Results from this study suggest that current methods used in evaluating schistosomiasis exposure in China may overestimate and bias measures of the risk of infection. Activity diaries adjusted for the time of day, duration and the percent body surface area exposed are cost-effective and practical instruments to accurately quantify human exposure in the vast lake regions of Southern China where most of the endemic schistosomiasis japonica occurs.     

The impact of print exposure quality and inference construction on syllogistic reasoning.

This study extended the work of S. Siddiqui, R. F. West, and K. E. Stanovich (1998), who studied the link between general print exposure and syllogistic reasoning. It was hypothesized that exposure to certain text structures that contain well-delineated logical forms, such as popularized scientific texts, would be a better predictor of deductive reasoning skill than general print exposure, which is not sensitive to the quality of an individual's reading activity. Furthermore, it was predicted that the ability to generate explanatory bridging inferences while reading would also be predictive of syllogistic reasoning. Undergraduate students (N = 112) were tested for vocabulary, nonverbal cognitive ability, exposure to general print, exposure to popularized scientific literature, and the ability to comprehend texts distinguished by the number of inferences that must be generated to support comprehension. Hierarchical multiple regression analyses showed that a combined measure of exposure to general and scientific literature was a significant predictor of syllogistic reasoning ability. Additionally, the ability to comprehend high-inference-load texts was related to solving syllogisms that were inconsistent with world knowledge, indicating an overlap in deductive reasoning skill and text comprehension processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Psychophysics of reading. XVIII. The effect of print size on reading speed in normal peripheral vision

Reading in peripheral vision is slow and requires large print, posing substantial difficulty for patients with central scotomata. The purpose of this study was to evaluate the effect of print size on reading speed at different eccentricities in normal peripheral vision. We hypothesized that reading speeds should remain invariant with eccentricity, as long as the print is appropriately scaled in size--the scaling hypothesis. The scaling hypothesis predicts that log-log plots of reading speed versus print size exhibit the same shape at all eccentricities, but shift along the print-size axis. Six normal observers read aloud single sentences (approximately 11 words in length) presented on a computer monitor, one word at a time, using rapid serial visual presentation (RSVP). We measured reading speeds (based on RSVP exposure durations yielding 80% correct) for eight print sizes at each of six retinal eccentricities, from 0 (foveal) to 20 deg in the inferior visual field. Consistent with the scaling hypothesis, plots of reading speed versus print size had the same shape at different eccentricities: reading speed increased with print size, up to a critical print size and was then constant at a maximum reading speed for larger print sizes. Also consistent with the scaling hypothesis, the plots shifted horizontally such that average values of the critical print size increased from 0.16 deg (fovea) to 2.22 deg (20 deg peripheral). Inconsistent with the scaling hypothesis, the plots also exhibited vertical shifts so that average values of the maximum reading speed decreased from 807 w.p.m. (fovea) to 135 w.p.m. (20 deg peripheral). Because the maximum reading speed is not invariant with eccentricity even when the print size was scaled, we reject the scaling hypothesis and conclude that print size is not the only factor limiting maximum reading speed in normal peripheral vision.     

Print exposure as a predictor of word reading and reading comprehension in disabled and nondisabled readers.

The relation of print exposure, measured by a revised version of A. E. Cunningham and K. E. Stanovich's (1990) Title Recognition Test (TRT), to word reading and reading comprehension was examined in disabled and nondisabled readers, Grades 5–9. In disabled readers, the TRT was a significant predictor of word reading when phonological skill was accounted for but not when orthographic ability was added to the regression equation, suggesting that the TRT overlaps considerably with orthographic skill. The TRT significantly predicted nondisabled readers' word reading after both phonological and orthographic skills were accounted for. The TRT contributed significantly to reading comprehension once variance was partialed from higher order reading processes for disabled readers only. The TRT's power to predict comprehension may be ascribed to the effects of print exposure on automaticity of word recognition, knowledge, or familiarization with text structure. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Front-door concentrations and personal exposures of Danish children to nitrogen dioxide

The aims of the study were to evaluate the front-door concentration of traffic exhaust fumes as a surrogate for the personal exposure of children and to study factors in the behavior and the environment of children that affect their personal exposure to nitrogen dioxide (NO(2)). The exposure to NO(2) of 103 children living in Copenhagen and 101 children living in rural areas of Denmark was studied by measuring average concentrations over 1 week with diffusive badge samplers placed outside the front door of the home, inside the child's bedroom, and on each child. Detailed information about the activities of the children involving potential exposure to NO(2) was noted in diaries. The results indicated that the front-door concentration of traffic pollution might be used to classify the personal exposure of urban children, although misclassification would be introduced. Multiple regression analysis showed several factors that affected the personal NO(2) exposure of the children independently, including the front-door concentration, the bedroom concentration, time spent outdoors, gas appliances used at home, passive smoking, and burning candles.     

How young children spend their time: Television and other activities.

Time-use diaries were collected over a 3-year period for 2 cohorts of 2- and 4-year-old children. TV viewing declined with age. Time spent in reading and educational activities increased with age on weekdays but declined on weekends. Time-use patterns were sex-stereotyped, and sex differences increased with age. As individuals' time in educational activities, social interaction, and video games increased, their time watching entertainment TV declined, but time spent playing covaried positively with entertainment TV. Educational TV viewing was not related to time spent in non-TV activities. Maternal education and home environment quality predicted frequent viewing of educational TV programs and infrequent viewing of entertainment TV. The results do not support a simple displacement hypothesis; the relations of TV viewing to other activities depend on the program content, the nature of the competing activity, and the environmental context. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Methods development for epidemiologic investigations of the health effects of prolonged ozone exposure. Part II. An approach to retrospective estimation of lifetime ozone exposure using a questionnaire and ambient monitoring data (California sites)

An extensive body of data supports a relation between acute exposures to ambient ozone and the occurrence of various acute respiratory symptoms and changes in measures of lung function. In contrast, relatively few data are available on the human health effects that result from long-term exposure to ambient ozone, Current efforts to study long-term ozone-related health effects are limited by the methods available for ascertaining lifetime exposures to ozone. The present feasibility study was undertaken as part of the Health Effects Institute's Environmental Epidemiology Planning Project (Health Effects Institute 1994) to (1) determine whether, in the context of an epidemiologic study, reliable estimates can be obtained for lifetime exposures to ozone by combining estimates from lifetime residential histories, typical activity patterns during life, and residence-specific ambient ozone monitoring data; (2) identify the minimum data required to produce reliable estimates of lifetime exposure; and (3) analyze the relations between various estimates of lifetime ozone exposure and measures of lung function. A convenience sample of 175 first-year students at the University of California, Berkeley, who lived all of their lives in selected areas of California (the Los Angeles Basin or the San Francisco Bay Area), were studied on two occasions (test and retest or test sessions 1 and 2), five to seven days apart. Residential and lifestyle data were obtained from a questionnaire: residence-based ambient ozone exposure values were assigned by interpolation of ambient ozone monitoring data to residential locations. Estimated lifetime exposure was based on average ozone levels between 10 a.m. and 6 p.m. and hours of exposure to ozone concentrations greater than 60 parts per billion (ppb). "Effective" lifetime exposure to ozone was based on a weighted average of estimated time spent in different ambient ozone environments as determined by different combinations of activity data. Pulmonary function was evaluated with flows and volumes from maximum expiratory flow-volume curves and slope of phase III of the single-breath nitrogen washout (SBNW) curves. Although the test-retest reliability of the residential history was acceptably high only for first and second residences, most of the unreliability for other residences came from residences occupied for relatively short durations. Therefore, the test-retest reliability of estimated lifetime exposure to ozone was high, with intraclass correlations greater than 0.90 for all approaches evaluated. Multiple, linear regression analyses showed a consistently negative relation between estimates of lifetime exposure to ozone and flows that reflect the physiology of pulmonary small airways. No relation was observed between lifetime ozone exposure and forced expiratory volume or the slope of phase III, and the relation between lifetime exposure and forced expiratory volume in one second was inconsistent. The results of the flow measures were unaffected by the method used to estimate lifetime exposure and gave effect estimates that were nearly identical. The data from this study indicate that useful and reproducible estimates of lifetime ozone exposure can be obtained in epidemiologic studies by using a residential history. However, the total burden of ozone to which the subjects were exposed cannot be determined accurately from such data. Nonetheless, the estimates so obtained appear to be associated with alterations in pulmonary function that are consistent with the predicted site of maximum effect of ozone in the human lung.     

Using children's literacy activities to predict growth in verbal cognitive skills: A longitudinal investigation.

Fourth-, fifth-, and sixth-grade children participated in a 2-year longitudinal study to determine the predictive validity of the Title Recognition Test (TRT) and the Author Recognition Test (ART), 2 checklist measures of individual differences in exposure to print. Multiple regression analyses confirmed the ability of the TRT to predict growth in receptive vocabulary, general information, spelling, sight vocabulary, verbal fluency, and reading comprehension even after controlling for age, recognition memory, and previous performance in the same cognitive competency area. The ART was found to be a less robust predictor. Although correlational, our results suggest that print exposure may be an independent contributor to cognitive growth in the verbal domain. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Knowledge growth and maintenance across the life span: The role of print exposure.

One hundred thirty-three college students (mean age?=?19.1 years) and 49 older individuals (mean age?=?79.9 years) completed 2 general knowledge tasks, a vocabulary task, a working memory task, a syllogistic reasoning task, and several measures of exposure to print. A series of hierarchical regression analyses indicated that when measures of exposure to print were used as control variables, the positive relationships between age and vocabulary, and age and declarative knowledge, were eliminated. Within each of the age groups, exposure to print was a significant predictor of vocabulary and declarative knowledge even after differences in working memory, general ability, and educational level were controlled. These results support the theory of fluid-crystallized intelligence and suggest a more prominent role for exposure to print in theories of individual differences in knowledge acquisition and maintenance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Assessing print exposure and orthographic processing skill in children: A quick measure of reading experience.

In a study of 3rd- and 4th-grade children it was established that orthographic processing ability can account for variance in word recognition skill after the variance due to phonological processing has been partialed out. This independent orthographic variance was related to performance on a new measure of individual differences in exposure to print, the Title Recognition Test, that has a very brief administration time. Additionally, some of the orthographic processing variance linked to word recognition ability was not shared with either phonological processing measures or with print exposure. The results of the study were supportive of the idea that there are individual differences in word recognition ability caused by variation in orthographic processing abilities that are in part determined by print exposure differences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The impact of caregiving and role strain on family life: Comparisons between mothers of children with cystic fibrosis and matched controls.

Compared daily activity patterns and extent of role strain between 20 mothers caring for an infant or toddler with cystic fibrosis (CF) and 20 matched control mothers. Ss completed a home interview, 3 questionnaire measures of role strain, and, subsequently, 6 daily phone diaries during which they tracked their day's activities. Ss in the CF group spent significantly more time in medical care activities on both week and weekend days, and more time in chores and child care on weekends. Additionally, Ss in the CF group had a less diverse pattern of recreation and spent less time in play and recreation activities. No differences between the 2 groups were found on self-report measures of role strain. However, on a behavioral role strain index, Ss in the CF group evidenced greater role strain. The importance of including both behavioral and perceptual measures of role strain is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Oral language and code-related precursors to reading: Evidence from a longitudinal structural model.

This study examined code-related and oral language precursors to reading in a longitudinal study of 626 children from preschool through 4th grade. Code-related precursors, including print concepts and phonological awareness, and oral language were assessed in preschool and kindergarten. Reading accuracy and reading comprehension skills were examined in 1st through 4th grades. Results demonstrated that (a) the relationship between code-related precursors and oral language is strong during preschool; (b) there is a high degree of continuity over time of both code-related and oral language abilities; (c) during early elementary school, reading ability is predominantly determined by the level of print knowledge and phonological awareness a child brings from kindergarten; and (d) in later elementary school, reading accuracy and reading comprehension appear to be 2 separate abilities that are influenced by different sets of skills. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Knowledge of storybooks as a predictor of young children's vocabulary.

Shared book reading provides a rich source of linguistic stimulation for young children. The authors examined whether variations in knowledge of storybooks (assumed to index factors such as frequency of shared reading) were related to vocabulary scores for 3–6 yr olds. In Exp 1, parents' knowledge of storybooks explained unique variance in children's receptive vocabulary scores after controlling for children's analytic intelligence, parents' exposure to adult reading material, and parents' education. In Exp 2, children's knowledge of storybooks explained unique variance in their receptive and expressive vocabulary scores after controlling for parents' exposure to print and socioeconomic status level. Children's knowledge of storybooks indexed cognitive factors as well as exposure. The findings obtained in the 2 experiments suggest that storybook experiences during the preschool years may be an important influence on the development of children's language skills. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Influence of verbal and nonverbal references to print on preschoolers' visual attention to print during storybook reading.

How much do preschool children look at print within storybooks when adults read to them? This study sought to answer this question as well as to examine the effects of adult verbal and nonverbal references to print on children's visual attention to print during storybook reading. Forty-four preschool-aged children participated in this study designed to determine the amount of visual attention children paid to print in 4 planned variations of storybook reading. Children's visual attention to print was examined when adults commented and questioned about print (verbal print condition) or pointed to and tracked the print (nonverbal print condition), relative to 2 comparison conditions (verbatim reading and verbal picture conditions). Results showed that children rarely look at print, with about 5%-6% of their fixations allocated to print in verbatim and verbal picture reading conditions. However, preschoolers' visual attention to print increases significantly when adults verbally and nonverbally reference print; both reading styles exerted similar effects. The authors conclude that explicit referencing of print is 1 way to increase young children's contacts with print during shared storybook reading. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sequence-based recognition of protein folds using the threading method and frameworks of globular proteins

In studies on mammalian parental investment, time spent suckling is often used as a predictor of the milk transferred from mother to infant. It is assumed that the rate of milk transfer is positively correlated with the time spent suckling. However, this assumption has not been tested and empirical studies show conflicting results. Nevertheless, in species in which suckling can readily be observed, time spent suckling is still used to measure milk transfer, although an increasing number of workers recognize that the measure is potentially inaccurate. A meta-analysis on studies that have correlated measures of time spent suckling with milk intake estimates based on weight gain revealed a weak positive relationship and significant heterogeneity between studies. Isotope-labelling techniques for the measurement of milk transfer independent of behaviour have been in use since the 1970s, particularly in studies of species in which suckling is difficult to observe. Only one study has attempted to correlate behavioural measures with independent isotope measures, and it found no relationship between the two measures. I suggest that researchers have avoided such a test as it is unlikely that a strong relationship will be found between milk transfer and suckling behaviour, and I discuss the various factors that confound the relationship and contribute to high heterogeneity between studies. Consequently, the assumption that milk transfer can be measured by time spent suckling has inadequate empirical foundation, and needs to be tested using isotope-labelling methods. Copyright 1998 The Association for the Study of Animal Behaviour     

Reading skills in hyperlexia: A developmental perspective.

Hyperlexia is characterized by advanced word-recognition skills in individuals who otherwise have pronounced cognitive, social, and linguistic handicaps. Language, word recognition, and reading-comprehension skills are reviewed to clarify the nature and core deficits associated with the disorder. It is concluded that hyperlexia should be viewed as part of the normal variation in reading skills, which are themselves associated with individual differences in phonological, orthographic, and semantic processing, short-term memory, and print exposure. A compulsive preoccupation with reading may also be crucial to the development of a hyperlexic reading profile. A theoretical framework, based on recent connectionist models of reading development, is described. This perspective provides a satisfactory account for how individual differences in a number of different skills can lead to a variety of manifestations of reading behavior, including hyperlexia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual requirements for reading

We have applied research on the visual psychophysics of reading to low vision assessment. Research on different aspects of the reading process found that reading rate rather than reading comprehension is more sensitive to variations in a subject's visual functioning or the stimulus properties of print. The research identified four different visual factors that significantly affect reading rate: (1) acuity reserve [print size relative to acuity threshold], (2) contrast reserve [print contrast relative to contrast threshold], (3) field of view [number of letters visible], and (4) in cases of maculopathy, central scotoma size. Our research indicates that fluent reading rates can be attained with a restricted field of view, as little as four characters. However, attainment of fluent reading levels requires that print size and contrast should be several times threshold and the diameter of a central scotoma should be less than 22 degrees. Although important clinical studies are lacking, we derived specific visual requirements for different reading rates from published experimental research to provide a starting point and to illustrate how visual requirements could be derived, even with poor correlations. Research has made significant progress toward the development of a comprehensive low vision assessment that will allow the practitioner to identify visual impediments to reading, other than reduced visual acuity. Having more fully characterized a visual impairment, the practitioner may tailor devices or interventions to the individual's needs and capabilities.