RESUMEN
The present study examined different conditions under which exclusion responding in conditional discrimination tasks would generate emergent equivalence relations in young children based on shared relationships with verbal labels. Both visual stimuli (Sets A, B, C, and D) and auditory stimuli (spoken words, Set N: N1 "correct"; N2: "incorrect") were used. Following a pilot study, three experiments were conducted, each involving eight preschool children. These experiments systematically investigated under which conditions responding by exclusion (i.e., responding away from a designated S- comparison in a matching to sample context) would generate sufficiently stable sample-S+ relations for arbitrary stimulus classes to establish. The results showed that young children's exclusion responding under test conditions will only contribute to arbitrary stimulus class formation and expansion when training has already established two arbitrary stimulus classes involving at least two stimuli each. For young children to demonstrate emergent conditional discrimination performances that are indicative of the formation of equivalence relations, it is necessary to have training and/or reinforced exposure to both S+ and S- control elements required for deriving the appropriate emergent relations with at least two conditional relations involving different samples. These findings not only contribute to existing research and theory on the conditions under which exclusion responding may contribute to fundamental language and learning processes, they also contribute to the experimental predictability of emergent conditional matching behaviours in preschool children by further unravelling the conditions under which emergent matching based on exclusion generates arbitrary conditional relations of equivalence.
Asunto(s)
Atención , Aprendizaje Discriminativo , Preescolar , Humanos , Proyectos PilotoRESUMEN
Little is known about the relationship between diurnal cortisol secretion patterns and cognitive function early in life. This population-based study examined whether diurnal cortisol rhythms and cognitive functioning in toddlers are related. Within the Generation R Study, parents of 364 infants (median age: 14.2 months) collected saliva samples at five moments during one day. We assessed the diurnal cortisol rhythm by calculating the area under the curve (AUC), the cortisol awakening response (CAR), and the diurnal slope. Verbal cognitive functioning and fine motor development was determined at age 18 months. Nonverbal cognitive functioning was assessed at age 30 months. A more positive CAR was associated with a lower risk of delay in language comprehension (OR per 1-SD CAR: 0.62, 95%CI: 0.40-0.98, p = .04), a lower risk of nonoptimal fine motor development (OR per 1-SD slope: 0.74, 95%CI: 0.57-0.96, p = .03), and a lower risk of delay in nonverbal cognitive development (OR per 1-SD CAR: 0.58, 95%CI: 0.38-0.90, p = .02). Also, children with flatter slopes had a lower risk of delay in nonverbal cognitive development (OR per 1-SD slope: 0.51, 95%CI: 0.34-0.76, p = .001). Higher AUC levels were associated with a higher risk of delay in language production. These results show that variations in diurnal cortisol rhythms are already associated with variations in cognitive functioning at a young age. Infants with a diurnal cortisol pattern indicative of less stress and more cortisol reactivity, that is, lower AUC levels and a more positive CAR, show a lower risk of delay in cognitive functioning as toddlers.
Asunto(s)
Desarrollo Infantil/fisiología , Ritmo Circadiano/fisiología , Cognición/fisiología , Hidrocortisona/análisis , Área Bajo la Curva , Preescolar , Femenino , Humanos , Hidrocortisona/metabolismo , Desarrollo del Lenguaje , Modelos Logísticos , Masculino , Pruebas Neuropsicológicas/estadística & datos numéricos , Saliva/metabolismo , Factores de TiempoRESUMEN
OBJECTIVE: Numerous studies in high-risk populations established that variations in infant neuromotor development predict poor cognitive function. It is unclear whether this association is found in the general population. Moreover, previous population-based studies mostly focused on motor milestone achievement. METHODS: This study was embedded in the Generation R Study, a population-based cohort in Rotterdam, the Netherlands. Neuromotor development was assessed with an adapted version of Touwen's Neurodevelopmental Examination when infants (1205 males, 1278 females) were on average 12 weeks old (standard deviation 1, range, 9-15 weeks). To measure language function at age 1.5 years, the MacArthur Short Form Vocabulary Checklist was used. At 2.5 years, mothers completed the Language Development Survey and the Parent Report of Children's Abilities measuring language and nonverbal cognitive functioning, respectively. RESULTS: After adjustment for confounders, less optimal neuromotor development, that is, more low tone symptoms, was associated with a delay in receptive language at 1.5 years (odds ratio [OR], 1.18; 95% confidence interval [CI], 1.05-1.34) and in expressive language at multiple time points (OR, 1.11; 95% CI, 1.02-1.21). Higher scores on overall neuromotor development, indicating a less optimal neuromotor development, was associated with an increased risk of a delay in nonverbal cognitive function at 2.5 years (OR, 1.19; 95% CI, 1.05-1.35). CONCLUSIONS: The results of this study suggest that infants with more low tone symptoms, indicating minor deviances from normal neuromotor development, are somewhat more vulnerable to language delays than those infants who do not have these symptoms.
Asunto(s)
Desarrollo Infantil/fisiología , Discapacidades del Desarrollo/epidemiología , Trastornos del Desarrollo del Lenguaje/epidemiología , Estudios de Cohortes , Discapacidades del Desarrollo/diagnóstico , Femenino , Humanos , Lactante , Desarrollo del Lenguaje , Trastornos del Desarrollo del Lenguaje/diagnóstico , Masculino , Países Bajos/epidemiología , RiesgoRESUMEN
PURPOSE: The authors tested associations between (a) parent-reported temporary vs. persistent vocabulary delay and (b) parent-reported behavioral/emotional problems in a sample of 5,497 young Dutch children participating in a prospective population-based study. METHOD: Mothers completed the MacArthur Communicative Development Inventory-Netherlands (Zink & Lejaegere, 2003) at age 18 months and the Language Development Survey (Rescorla, 1989) at age 30 months, with expressive vocabulary delay defined as scores in the lowest 15th age- and gender-specific percentiles. The Child Behavior Checklist (Achenbach & Rescorla, 2000) was completed by mothers when their children were age 18 months and by both parents when their children were age 36 months, from which Internalizing Problems and Externalizing Problems scores were analyzed. RESULTS: All analyses were adjusted for covariates. Expressive vocabulary delay at age 18 months was weakly related to Internalizing Problems scores at age 18 months as well as mother-reported Externalizing and Internalizing Problems scores at age 36 months (the latter for boys only). Expressive vocabulary delay at age 30 months was weakly associated with mother-reported Externalizing and Internalizing Problems scores (the latter for boys only) and father-reported Internalizing Problems scores. Persistent expressive vocabulary delay predicted the highest risk of mother-reported internalizing and externalizing problems at age 36 months. CONCLUSION: This population-based study showed modest associations between vocabulary delay and behavioral/emotional problems detectable from 18 months onward.
Asunto(s)
Trastornos de la Conducta Infantil/epidemiología , Conducta Infantil , Emociones , Trastornos del Desarrollo del Lenguaje/epidemiología , Vocabulario , Adulto , Factores de Edad , Trastornos de la Conducta Infantil/psicología , Lenguaje Infantil , Preescolar , Estudios de Cohortes , Femenino , Humanos , Desarrollo del Lenguaje , Trastornos del Desarrollo del Lenguaje/psicología , Masculino , Edad Materna , Países Bajos/epidemiología , Estudios Prospectivos , Factores de RiesgoRESUMEN
BACKGROUND: Neuroimaging findings have provided evidence for a relation between variations in brain structures and attention deficit/hyperactivity disorder (ADHD). However, longitudinal neuroimaging studies are typically confined to children who have already been diagnosed with ADHD. In a population-based study, we aimed to characterize the prospective association between brain structures measured during infancy and executive function and attention deficit/hyperactivity problems assessed at preschool age. METHODS: In the Generation R Study, the corpus callosum length, the gangliothalamic ovoid diameter (encompassing the basal ganglia and thalamus), and the ventricular volume were measured in 784 6-week-old children using cranial postnatal ultrasounds. Parents rated executive functioning at 4 years using the behavior rating inventory of executive function-preschool version in five dimensions: inhibition, shifting, emotional control, working memory, and planning/organizing. Attention deficit/hyperactivity problems were assessed at ages 3 and 5 years using the child behavior checklist. RESULTS: A smaller corpus callosum length during infancy was associated with greater deficits in executive functioning at 4 years. This was accounted for by higher problem scores on inhibition and emotional control. The corpus callosum length during infancy did not predict attention deficit/hyperactivity problem at 3 and 5 years, when controlling for the confounders. We did not find any relation between gangliothalamic ovoid diameter and executive function or Attention deficit/hyperactivity problem. CONCLUSIONS: Variations in brain structures detectible in infants predicted subtle impairments in inhibition and emotional control. However, in this population-based study, we could not demonstrate that early structural brain variations precede symptoms of ADHD.
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Trastorno por Déficit de Atención con Hiperactividad/patología , Encéfalo/patología , Desarrollo Infantil , Función Ejecutiva , Trastorno por Déficit de Atención con Hiperactividad/epidemiología , Ganglios Basales/diagnóstico por imagen , Ventrículos Cerebrales/diagnóstico por imagen , Preescolar , Cuerpo Calloso/diagnóstico por imagen , Ecoencefalografía , Femenino , Humanos , Lactante , Estudios Longitudinales , Masculino , Países Bajos/epidemiología , Tálamo/diagnóstico por imagenRESUMEN
AIM: General developmental outcome is known to be good in school-aged children who experienced febrile seizures. We examined cognitive and behavioural outcomes in preschool children with febrile seizures, including language and executive functioning outcomes. METHOD: This work was performed in the Generation R Study, a population-based cohort study in Rotterdam from early fetal life onwards. Information about the occurrence of febrile seizures was collected by questionnaires at the ages of 1, 2, and 3 years. At the age of 3 years, behaviour and emotion were assessed using the Child Behavior Checklist. Information on expressive language development was obtained by the Language Development Survey at the age of 2 years 6 months. To assess executive functioning, parents completed the Behaviour Rating Inventory of Executive Function - Preschool Version when their children were 4 years old. Final analyses were based on 3157 children. RESULTS: No associations were found between febrile seizures and the risk of behavioural problems or executive functioning. In contrast to single febrile seizures, recurrent febrile seizures were significantly associated with an increased risk of delayed vocabulary development (odds ratio 3.22, [95% confidence interval 1.30-7.94]). INTERPRETATION: Febrile seizures are not associated with problem behaviour or executive functioning in preschool children, but the results suggest that children with recurrent febrile seizures might be at risk for delayed language development.
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Conducta Infantil/fisiología , Desarrollo Infantil/fisiología , Desarrollo del Lenguaje , Convulsiones Febriles/complicaciones , Preescolar , Estudios de Cohortes , Discapacidades del Desarrollo/etiología , Función Ejecutiva/fisiología , Femenino , Humanos , Lactante , Masculino , Estudios Prospectivos , Recurrencia , Riesgo , Convulsiones Febriles/fisiopatología , Encuestas y CuestionariosRESUMEN
BACKGROUND: Post-term birth, defined as birth after pregnancy duration of 42 weeks, is associated with increased neonatal morbidity and mortality. The long-term consequences of post-term birth are unknown. We assessed the association of post-term birth with problem behaviour in early childhood. METHODS: The study was performed in a large population-based prospective cohort study in Rotterdam, The Netherlands. Pregnant mothers enrolled between 2001 and 2005. Of a cohort of 5145 children, 382 (7%) were born post-term, and 226 (4%) were born preterm. Parents completed a standardized and validated behavioural checklist (Child Behavior Checklist, CBCL/1.5-5) when their children were 1.5 and 3 years old. We examined the relation between gestational age (GA) at birth, based on early fetal ultrasound examination, and problem behaviour with regression analyses, adjusting for socio-economic and pregnancy-related confounders. RESULTS: A quadratic relationship between GA at birth and problem behaviour indicates that both preterm and post-term children have higher behavioural and emotional problem scores than the term born children. Compared with term born children, post-term born children had a higher risk for overall problem behaviour [odds ratio (OR) = 2.10, 95% confidence interval (CI) = 1.32-3.36] and were almost two and a half times as likely to have attention deficit / hyperactivity problem behaviour (OR = 2.44, 95% CI = 1.38-4.32). CONCLUSIONS: Post-term birth was associated with more behavioural and emotional problems in early childhood, especially attention deficit / hyperactivity problem behaviour. When considering expectant management, this aspect of post-term pregnancy should be taken into account.
Asunto(s)
Síntomas Afectivos/epidemiología , Trastornos de la Conducta Infantil/epidemiología , Edad Gestacional , Posmaduro/psicología , Adulto , Trastorno por Déficit de Atención con Hiperactividad/epidemiología , Preescolar , Emociones , Femenino , Humanos , Lactante , Recién Nacido , Recien Nacido Prematuro , Masculino , Países Bajos/epidemiología , Embarazo , Estudios Prospectivos , Análisis de Regresión , Medición de Riesgo , Factores Socioeconómicos , Ultrasonografía PrenatalRESUMEN
PURPOSE: The authors investigated continuity and discontinuity of vocabulary skills in a population-based cohort in the Netherlands. METHOD: Mothers of 3,759 children completed the Dutch version of the MacArthur Short Form Vocabulary Checklist (Zink & Lejaegere, 2003) at 18 months and a Dutch translation of the Language Development Survey (Rescorla, 1989) at 30 months. At both ages, expressive vocabulary delay was defined as vocabulary scores <10th age- and gender-specific percentile. RESULTS: Of the children, 85.2% had normal vocabulary development at both ages, 6.2% were "late bloomers," 6.0% had late onset expressive vocabulary delay, and 2.6% had persistent expressive vocabulary delay. Word production and comprehension at 18 months explained 11.5% of the variance in 30-month vocabulary scores, with low birth weight, child age, gender and ethnicity, maternal age and education, and parenting stress explaining an additional 6.2%. Multinomial logistic regression was used to identify biological, demographic, and psychological factors associated with each of the vocabulary delay outcome groups relative to the typically developing group. CONCLUSIONS: Although multiple perinatal, demographic, and maternal psychosocial factors significantly predicted vocabulary skills at 30 months, positive predictive value and sensitivity were low. Future studies should address to what extent additional factors, such as brain maturation and genetic influences, can improve the prediction and understanding of continuity and discontinuity of language delay.
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Lenguaje Infantil , Trastornos del Desarrollo del Lenguaje/diagnóstico , Desarrollo del Lenguaje , Vocabulario , Peso al Nacer , Preescolar , Estudios de Cohortes , Femenino , Humanos , Trastornos del Desarrollo del Lenguaje/epidemiología , Masculino , Países Bajos/epidemiología , Relaciones Padres-Hijo , Padres/psicología , Valor Predictivo de las Pruebas , Psicología Infantil , Psicometría/estadística & datos numéricos , Estrés Psicológico/epidemiología , Estrés Psicológico/psicología , Encuestas y CuestionariosRESUMEN
CONTEXT: Thyroid hormones are essential for neurodevelopment from early pregnancy onward. Yet population-based data on the association between maternal thyroid function in early pregnancy and children's cognitive development are sparse. OBJECTIVE: Our objective was to study associations of maternal hypothyroxinemia and of early pregnancy maternal TSH and free T(4)(FT(4)) levels across the entire range with cognitive functioning in early childhood. DESIGN AND SETTING: We conducted a population-based cohort in The Netherlands. PARTICIPANTS: Participants included 3659 children and their mothers. MAIN MEASURES: In pregnant women with normal TSH levels at 13 wk gestation (SD = 1.7), mild and severe maternal hypothyroxinemia were defined as FT(4) concentrations below the 10th and 5th percentile, respectively. Children's expressive vocabulary at 18 months was reported by mothers using the MacArthur Communicative Development Inventory. At 30 months, mothers completed the Language Development Survey and the Parent Report of Children's Abilities measuring verbal and nonverbal cognitive functioning. RESULTS: Maternal TSH was not related to the cognitive outcomes. An increase in maternal FT(4) predicted a lower risk of expressive language delay at 30 months only. However, both mild and severe maternal hypothyroxinemia was associated with a higher risk of expressive language delay across all ages [odds ratio (OR) = 1.44; 95% confidence interval (CI) = 1.09-1.91; P = 0.010 and OR = 1.80; 95% CI = 1.24-2.61; P = 0.002, respectively]. Severe maternal hypothyroxinemia also predicted a higher risk of nonverbal cognitive delay (OR = 2.03; 95% CI = 1.22-3.39; P = 0.007). CONCLUSIONS: Maternal hypothyroxinemia is a risk factor for cognitive delay in early childhood.
Asunto(s)
Desarrollo Infantil/fisiología , Cognición/fisiología , Primer Trimestre del Embarazo/fisiología , Glándula Tiroides/fisiología , Adulto , Niño , Estudios de Cohortes , Discapacidades del Desarrollo/sangre , Discapacidades del Desarrollo/etiología , Composición Familiar , Femenino , Humanos , Hipotiroidismo/sangre , Hipotiroidismo/complicaciones , Hipotiroidismo/fisiopatología , Relaciones Materno-Fetales , Madres , Embarazo , Primer Trimestre del Embarazo/sangre , Efectos Tardíos de la Exposición Prenatal/sangre , Efectos Tardíos de la Exposición Prenatal/fisiopatología , Factores de Riesgo , Pruebas de Función de la Tiroides , Tirotropina/sangreRESUMEN
AIM: The aim of this study was to investigate within a population-based cohort of 4384 infants (2182 males, 2202 females) whether fetal growth from early pregnancy onwards is related to infant development and whether this potential relationship is independent of postnatal growth. METHOD: Ultrasound measurements were performed in early, mid-, and late pregnancy. Estimated fetal weight was calculated using head and abdominal circumference and femur length. Infant development was measured with the Minnesota Infant Development Inventory at 12 months (SD 1.1mo, range 10-17mo). Information on postnatal head size and body weight at 7 months was obtained from medical records. RESULTS: After adjusting for potential confounders and for postnatal growth, faster fetal weight gain from mid- to late pregnancy predicted a reduced risk of delayed social development (odds ratio [OR] 0.82; 95% confidence interval [CI] 0.71-0.95, p=0.008), self-help abilities (OR 0.84; 95% CI 0.73-0.98, p=0.023), and overall infant development (OR 0.65; 95% CI 0.49-0.87, p=0.003). Similar findings were observed for fetal head growth from mid- to late pregnancy. INTERPRETATION: Faster fetal growth predicts a lower risk of delayed infant development independent of postnatal growth. These results suggest that reduced fetal growth between mid- and late pregnancy may determine subsequent developmental outcomes.
Asunto(s)
Desarrollo Infantil , Feto/embriología , Segundo Trimestre del Embarazo , Tercer Trimestre del Embarazo , Estudios de Cohortes , Discapacidades del Desarrollo/epidemiología , Femenino , Feto/anatomía & histología , Estudios de Seguimiento , Cabeza/anatomía & histología , Cabeza/embriología , Cabeza/crecimiento & desarrollo , Humanos , Lactante , Masculino , Embarazo , Riesgo , Conducta Social , Ultrasonografía PrenatalRESUMEN
The vulnerability for behavioral problems is partly shaped in fetal life. Numerous studies have related indicators of intrauterine growth, for example, birth weight and body size, to behavioral development. We investigated whether fetal size in mid- and late pregnancy is related to infant irritability and alertness. In a population-based birth cohort of 4,255 singleton full-term infants ultrasound measurements of fetal head and abdominal circumference in mid- and late pregnancy were performed. Infant irritability and alertness scores were obtained by the Mother and Baby Scales at 3 months and z-standardized. Multiple linear regression analyses revealed curvilinear associations (inverted J-shape) of measures of fetal size in both mid- and late pregnancy with infant alertness. Fetal size characteristics were not associated with infant irritability. These results suggest that alterations of intrauterine growth affecting infant alertness are already detectable from mid-pregnancy onwards.