Kathleen S. Gorman

Early supplementary feeding and cognition : effects over two decades

The study reported in this Monograph of the effects of early supplementary feeding on cognition included two data collection periods: a longitudinal investigation spanning the years 1969-1977 and a cross-sectional follow-up carried out in 1988-1989. The study was conducted in four rural villages in Guatemala and compared the differential effects of exposure in childhood (0-7 years) to an Atole supplement (11.5 g of protein; 163 kcal) or a Fresco supplement (59 kcal) on performance on a battery of psychoeducational and information-processing tests in adolescence and young adulthood (11-24 years). In this report, particular attention is given to a cohort of subjects who were exposed to the supplement prenatally and during at least the first 2 years of postnatal life. Data on this subsample are contrasted with those on a cohort of subjects who received the supplement only after 24 months of life. The Monograph also reports results from an analysis of the supplementation effects in infancy and early childhood. Consistent differences between groups on the psychoeducational tests were observed. Adolescents from Atole villages scored significantly higher on tests of knowledge, numeracy, reading, and vocabulary than Fresco subjects. Atole was also associated with a faster reaction time in information-processing tasks. Significant interactions helped identify two groups who benefited more from the Atole treatment: those at the lowest levels of socioeconomic status and those who attained the highest levels of primary schooling. The consistent differences in test performance established in the follow-up assessment contrast sharply with the few and less pronounced between-group differences observed in the infancy and preschool periods. After close scrutiny of alternative hypotheses, it is concluded that nutritional differences provide the strongest explanation for the test performance differences observed in the follow-up between the subjects exposed to the Atole and those exposed to the Fresco supplement.

Nutrition in Early Life and the Fulfillment of Intellectual Potential

The effects of early supplementary feeding on cognition are investigated using data collected during two periods in four Guatemalan villages. The first was the Institute of Nutrition of Central America and Panama (INCAP) longitudinal study from 1969 to 1977 and the second was a cross-sectional follow-up of former participants carried out in 1988-1989. The principal objective of these studies was to assess the differential effect of two dietary supplements, Atole containing 163 kcal/682 kJ and 11.5 g protein per cup or 180 mL and Fresco containing 59 kcal/247 kJ and 0 g protein per cup, that were given to mothers, infants and young children. Performance was assessed on a battery of psychoeducational and information processing tests that were administered during adolescence. Consistent differences between groups were observed on psychoeducational tests. Subjects receiving Atole scored significantly higher on tests of knowledge, numeracy, reading and vocabulary than those given Fresco. Atole ingestion also was associated with faster reaction time in information processing tasks. In addition, there were significant interactions between type of dietary supplement and socioeconomic status (SES) of subjects. In Atole villages, there were no differences in performance between subjects in the lowest and highest SES categories. On the other hand, performance in Fresco villages was best in the highest compared with the lowest SES group. After close scrutiny of alternative hypotheses, it is concluded that dietary changes produced by supplementation provide the strongest explanation for the test performance differences observed in the follow-up between subjects exposed to Atole and those exposed to Fresco supplementation.

The relationship between sustained attention and cognitive performance in 17–24-month old toddlers

The purpose of this study was to investigate individual differences in sustained attention and task performance with toddlers. Participants were 61 17–24-month old toddlers. Indices of sustained attention (duration of attention and frequency of off-task glances) were assessed during two 4 min problem solving tasks, and then related to problem solving and the mental scale of the Bayley scales of infant development-II (BSID-II). As expected, toddlers who attended to tasks for longer periods of time were more successful at problem solving, and had higher scores on the BSID-II than toddlers who attended for shorter periods of time. In addition, older toddlers had longer attention spans, more frequent off-task glances, and were more successful at problem solving than younger toddlers. Interestingly, toddlers with more frequent off-task glances had longer attention spans, were more successful at problem solving, and had higher BSID-II scores than peers with fewer off-task glances. These findings suggest that although behavioural indices can be used to identify sustained attention, the relationship between behaviours thought to capture distractibility and attention is more complex than had been previously assumed. Results are discussed in the context of current theories of infant attention and cognitive performance. Copyright

Determinants of School Performance in Guatemala: Family Background Characteristics and Early Abilities

The purpose of this study was to explore how two sets of antecedent variables contribute to variation in school enrolment and performance in four villages in rural Guatemala. Measures of preschool cognition and indicators of family socioeconomic status (maternal education level and house quality) predicted school enrolment for boys and girls. Similarly, for those who went to school, socioeconomic status and preschool abilities were associated with age-atentry, the number of grades passed and failed, and the maximum grade attained. Multivariate regression analyses indicate that preschool abilities, after controlling for indicators of family background, explain significant portions of variance in age of entry and other measures of school performance. The results are interpreted in the light of the cumulative deficit hypothesis which postulates that early environmental disadvantages increase over time. These data indicate that the school experience contributes to maintaining, rather than reducing, social class differences.

The Contribution of Schooling to Literacy in Guatemala.

The authors of this paper examine the relationship between level of schooling and literacy attainment in four rural communities in Guatemala. They first identify the grade at which most children become literate. Secondly, they estimate the net contribution of schooling to literacy. Finally, they ask whether literacy skills acquired under poor or restricted school conditions are likely to be lost over time after the pupil has left school.

Long-Term Developmental Consequences of Intrauterine and Postnatal Growth Retardation in Rural Guatemala

Knowledge on the developmental consequences of low birth weight (LBW) infants is derived primarily from research in developed countries such as the United States and Great Britain (Friedman & Sigman, 1981; Vietze & Vaughan, 1988). In that context it is now recognized that except for extreme cases, LBW is not a sufficient cause for developmental deviation. In fact, the final developmental outcome of LBW infants is often determined by the nature of the social environment to which the LBW child is exposed after birth rather than by the child’s intrauterine history (Hack & Breslau, 1988; Sameroff & Chandler, 1975; Werner & Smith, 1977). The social environment acts as either a buffer against the potential effects of the prenatal trauma or as a remedial agent that corrects a deviation that may be apparent in early life (Ricciuti, 1989).