Felix-Sebastian Koch

Psychological Stress and Obesity

OBJECTIVE To examine whether there is a relationship between psychological stress in the family and obesity in 5- to 6-year-old children. STUDY DESIGN A total of 7443 Swedish families reported on psychological stress across 4 domains as part of the prospective All Babies in Southeast Sweden-project (ABIS). Domains assessed included serious life events, parenting stress, lack of social support, and parental worries. These variables were summarized in cross-sectional and longitudinal composite measures of psychological stress. Logistic regression models were used to calculate odds ratios for childhood obesity for psychological stress. RESULTS A total of 4.2% of the children were obese according to age-adjusted international standards. Children from families that reported stress in at least 2 of the 4 domains assessed had significantly higher adjusted odds ratios (OR) for obesity, both cross-sectionally (OR, 2.1; 95% CI, 1.3-3.5; P < .01) and longitudinally (OR, 2.6; 95% CI, 1.3-5.4, P < .01). CONCLUSION Psychological stress in the family may be a contributing factor for childhood obesity. This finding underscores how important it is to give children with obesity and their families psychological and social support in addition to recommendations about changing life style.

Higher maternal education is associated with favourable growth of young children in different countries

Background Childhood growth affects long-term health and could contribute to health inequalities that persist throughout life. Methods We compared growth data of 4-year-old to 6-year-old children born 1997–2002 in UK (n=15 168), Sweden (n=6749) and rural China (n=10 327). SD scores (SDS) were calculated against the WHO Growth Standard. Obesity and overweight were defined by the International Obesity Taskforce cut-offs, and stunting, underweight and thinness by height, weight or body mass index (BMI)<−2 SDS. Associations with maternal education were standardised by calculating the Slope Index of Inequality (SII). Results Mean SDS height, weight and BMI in the UK (−0.01, 0.42, 0.62, respectively) and Sweden (0.45, 0.59, 0.45) were higher than in China (−0.98, −0.82, −0.29). Higher maternal education was consistently associated with taller offspring height SDS (SII: UK 0.25; Sweden 0.17; China 1.06). Underweight and stunting were less common in the UK (prevalence: 0.6% and 2.2%, respectively) and Sweden (0.3% and 0.6%) than in China (9.5% and 16.4%), where these outcomes were inversely associated with maternal education (SII: −25.8% and −12.7%). Obesity prevalence in the UK, Sweden and China was 4.8%, 3.7% and 0.4%, respectively. Maternal education was inversely associated with offspring obesity in the UK (SII: −3.3%) and Sweden (−2.8%), but not in China (+0.3%). Conclusions Higher maternal education was associated with more favourable growth in young children: lower obesity and overweight in the UK and Sweden, and lower stunting and underweight in rural China. Public health strategies to optimise growth in early childhood need to acknowledge socioeconomic factors, but possibly with a different emphasis in different settings.

Early declarative memory predicts productive language: A longitudinal study of deferred imitation and communication at 9 and 16months.

Deferred imitation (DI) may be regarded as an early declarative-like memory ability shaping the infants ability to learn about novelties and regularities of the surrounding world. In the current longitudinal study, infants were assessed at 9 and 16months. DI was assessed using five novel objects. Each infants communicative development was measured by parental questionnaires. The results indicate stability in DI performance and early communicative development between 9 and 16months. The early achievers at 9months were still advanced at 16months. Results also identified a predictive relationship between the infants gestural development at 9months and the infants productive and receptive language at 16months. Moreover, the results show that declarative memory, measured with DI, and gestural communication at 9months independently predict productive language at 16months. These findings suggest a connection between the ability to form non-linguistic and linguistic mental representations. These results indicate that the childs DI ability when predominantly preverbal might be regarded as an early domain-general declarative memory ability underlying early productive language development.

Saccadic Reaction Times in Infants and Adults: Spatiotemporal Factors, Gender, and Interlaboratory Variation.

Saccade latency is widely used across infant psychology to investigate infants’ understanding of events. Interpreting particular latency values requires knowledge of standard saccadic RTs, but there is no consensus as to typical values. This study provides standard estimates of infants’ (n = 194, ages 9 to 15 months) saccadic RTs under a range of different spatiotemporal conditions. To investigate the reliability of such standard estimates, data is collected at 4 laboratories in 3 countries. Results indicate that reactions to the appearance of a new object are much faster than reactions to the deflection of a currently fixated moving object; upward saccades are slower than downward or horizontal saccades; reactions to more peripheral stimuli are much slower; and this slowdown is greater for boys than girls. There was little decrease in saccadic RTs between 9 and 15 months, indicating that the period of slow development which is protracted into adolescence begins in late infancy. Except for appearance and deflection differences, infant effects were weak or absent in adults (n = 40). Latency estimates and spatiotemporal effects on latency were generally consistent across laboratories, but a number of lab differences in factors such as individual variation were found. Some but not all differences were attributed to minor procedural differences, highlighting the importance of replication. Confidence intervals (95%) for infants’ median reaction latencies for appearance stimuli were 242 to 250 ms and for deflection stimuli 350 to 367 ms.

Thirteen- to Sixteen-Months Old Infants Are Able to Imitate a Novel Act from Memory in Both Unfamiliar and Familiar Settings But Do Not Show Evidence of Rational Inferential Processes

Gergely et al. (2002) reported that children imitated a novel action – illuminating a light-box by using the forehead – after a delay significantly more often if the hands of the experimenter had been visible in comparison with if they had been covered. In an attempt to explore these findings we conducted two studies with a total N of 63 children. Both studies investigated deferred imitation of the action in two conditions, with the hands of the experimenter visible or covered, but the settings differed. Study 1 (n = 30; mean age = 16.6 months) was carried out in an unfamiliar environment (a laboratory setting) while Study 2 (n = 33; mean age = 13.3 months) was conducted in familiar surroundings (at home or at day care). The results showed that 50% of the children in Study 1 and 42.4% in Study 2 evidenced deferred imitation as compared to only 4.9% (n = 2) in the baseline condition. However, in none of the studies did the children use inferential processes when imitating, we detected no significant differences between the two conditions, hands visible or hands covered. The findings add to the validity of the head touch procedure as a measure of declarative-like memory processes in the pre-verbal child. At the same time the findings question the robustness of the concept ‘rational imitation,’ it seems not as easy as expected to elicit a response based on rational inferential processes in this age group.