The aim of this study was to assess the performance of the children in the study on some psychometric tests and to find out whether iron deficiency had any effect on cognitive skills as measured by the selected psychometric tests. The study also wanted to find out if there would be any gender differences on the psychometric tests. A sample of 810 children was selected from eleven schools from the rural Southern part of KwaZulu-Natal. The children were of ages eight to ten years old, were all Zulu speaking and in standard one. Blood samples were taken from all the children to determine iron levels. Psychometric tests viz., the Symbol Digit Modalities Test, Raven's Coloured Progressive Matrices, Rey's Auditory Verbal Learning Test and Young's Group Mathematics Test, were all administered to measure cognitive performance. The results showed no significant iron level effects on most of the measured cognitive skills. There were some significant gender effects on all the psychometric tests except for the Maths test. There was general low performance on all the psychometric tests. Therefore, the results highlighted the importance of designing more tests that can be standardized and thus be applicable to Zulu speaking children and other children with similar backgrounds. The tests should also be able to tap into the cognitive skills that may be affected by iron levels. There is also a great need for studies looking at the lower end of iron deficiency. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 1998.

Nel presente lavoro di tesi sono riportati i risultati di un innovativo progetto di ricerca longitudinale nell'ambito della psicobiologia. I recenti progressi nel campo dell'epigenetica sono stati applicati allo studio delle conseguenze di esperienze avverse precoci sullo sviluppo socio-emozionale in bambini nati fortemente pretermine. La nascita pretermine costituisce un fattore di rischio per lo sviluppo socio-emozionale, in parte per l'esposizione ad eventi stressanti (es.: dolore neonatale) durante l'ospedalizzazione in terapia intensiva neonatale (TIN). L'epigenetica si riferisce a processi biochimici altamente sensibili alle esperienze ambientali e che alterano la funzione di trascrizione di specifici geni, senza modificare la struttura della sequenza di DNA. Il candidato ha sviluppato un razionale clinicamente rilevante per la ricerca epigenetica comportamentale della prematurità. Inoltre il progetto di ricerca ha dimostrato che il livello di esposizione a procedure dolorose si associa a esiti avversi sul piano temperamentale e della risposta allo stress a tre mesi e che tale associazione è mediata da alterazioni epigenetiche a livello del gene che codifica per il trasportatore della serotonina. Le implicazioni teoriche, cliniche ed etiche di questi risultati sono trattate nella sezione conclusiva. Il progetto di epigenetica comportamentale della prematurità fornisce una nuova prospettiva teorica ed empirica sul tema dell’interazione tra genetica ed ambiente. / In the present work, the candidate reports the results of an innovative longitudinal research project in the field of psychobiology. The recent epigenetic progresses have been applied to the study of the consequences of early adverse event exposures on the socio-emotional development of very preterm infants. Preterm birth is a major concern for socio-emotional development, partly due to the exposure to adverse stressful stimulations (i.e., skin-breaking procedures) during the Neonatal Intensive Care Unit (NICU) stay. Epigenetics refers to biochemical processes which are sensitive to environmental cues and which alter the transcriptional activity of specific genes without changing the DNA structure. The candidate has developed a clinically relevant rationale for preterm behavioral epigenetics (PBE). The research project has demonstrated that the early exposure to high levels of skin-breaking procedures during NICU stay associate with non-optimal temperamental profile and stress regulation at 3 months of age. This association was mediated by epigenetic modifications (DNA methylation) of the stress-related gene encoding for serotonin transporter. The theoretical, clinical and ethical implications of these findings are discussed further in the final section of the thesis. The PBE project provides a new framework for the issue of the interconnections between nature and nurture.