Expectation of reward differentially modulates executive inhibition

Abstract: Background: Inhibitory control, a key modulatory component of cognition guiding strategy and behaviour, can be affected by diverse contingencies. We explore here the effect of expectation of reward over behavioural adjustment in a Stop Signal Task modulated by reward. We hypothesize that cognitive control is modulated by different expectation of the reward. Methods: Participants were allocated to two groups differing in their degree of knowledge in what to expect from rewards. Expected Specific Reward participants (N = 21) were informed of the different monetary feedbacks they would receive after each successful inhibition. Unexpected Reward participants (N = 24) were only told that they would receive monetary reward after correct inhibitory trials, but not the amounts or differences. Results: Our results confirmed previous observations demonstrating a “kick-start effect” where a high reward feedback at the beginning of the task increases response inhibition. The Expected Specific Reward condition seems also to improve inhibitory control -as measured by the stop signal reaction time (SSRT)-, compared to the Unexpected Reward group. Conclusions: Knowledge of reward magnitudes seems to play a role in cognitive control irrespective of feedback magnitude. The manipulation of reward expectation appears to trigger different strategies for cognitive control, inducing a bottom-up effect of external cues, or a top-down effect given by the anticipation of incoming rewards. This is an early exploration to unearth possible higher order modulators - expectation and motivation- of cognitive control. This approach aims to gain insight into diverse psychopathological conditions related to impulsivity and altered reward systems such as Attention Deficit Hyperactive Disorder (ADHD), personality disorders, substance abuse, pathological gambling and cognitive aspects of Parkinson Disease

Attention deficit hyperactivity disorder: From parents to children

Introduction: Multiple studies of attention deficit hyperactivity disorder (ADHD) have recognised a heritability factor in that a higher frequency of the disorder is observed in children with an affected relative. Our aim was to determine the association between ADHD symptoms in young children enrolled in five schools in Bogota and a history of ADHD symptoms in their parents using the Wender-Utah Rating Scale. Methodology: Case–control study of participants selected according to DSM-IV criteria for ADHD and the Behavioral Assessment System for Children (BASC) completed by parents and teachers; the WISC-IV scale was used to exclude children with cognitive deficit. Parents completed the Wender-Utah Rating Scale to retrospectively identify any ADHD symptoms in childhood. A score of 36 was used as a cut-off point. Results: The study included 202 children: 117 cases and 85 controls. A positive history of ADHD symptoms in childhood was identified for 16% of 175 mothers and 20.6% of 141 fathers. The presence of symptoms in either parent, especially the mother, constitutes a significant risk factor for ADHD in children and this relationship persists after controlling for different variables. If both parents have the disorder, the risk tends to increase. Conclusion: Although ADHD has been linked to a genetic component, other environmental factors may be involved in the disorder. Resumen: Introducción: En el trastorno por déficit de atención e hiperactividad (TDAH), la heredabilidad ha sido reconocida en múltiples estudios. En este sentido, se ha observado una mayor frecuencia del trastorno en niños con familiares afectados. El objetivo fue determinar la asociación entre la presencia de síntomas de TDAH en niños escolares de 5 instituciones educativas de Bogotá y el antecedente de síntomas de TDAH en sus padres utilizando el cuestionario de Wender-Utah. Metodología: Estudio de casos y controles seleccionados de acuerdo con los criterios DSM-IV para TDAH, la escala multifuncional de la conducta (BASC) para padres y maestros y WISC-IV para descartar déficit cognitivo. A los padres se les aplicó un cuestionario de Wender-Utah para identificar de manera retrospectiva síntomas de TDAH en su infancia. Un score de 36 fue tomado como punto de corte. Resultados: De 202 niños disponibles, 117 fueron casos y 85 controles. Un 16% de 175 madres y un 20,6% de 141 padres tuvieron antecedentes positivos para síntomas de TDAH en la infancia. La presencia de síntomas en alguno de los progenitores, principalmente en la madre, es un factor de riesgo significativo para la presencia de TDAH en los niños y esta relación persiste si se controla por diferentes variables. Si los 2 progenitores tienen el cuadro, existe una tendencia a que el riesgo aumente. Conclusión: A pesar de que el TDAH se ha asociado a un componente genético, otros factores del entorno pueden estar involucrados en la génesis del trastorno. Keywords: Attention deficit hyperactivity disorder, DSM-IV, Behavior Assessment System for Children (BASC), Wender-Utah Rating Scale, Behaviour, Palabras clave: Trastorno por déficit de atención, DSM-IV, Escala multifuncional de la conducta (BASC), Escala de Wender-Utah, Conduct

Characterizing older adult patients suffering from epilepsy in two hospitals in Bogotá (Colombia)

Epilepsy’s overall prevalence in Colombia is 1.13%. Its prevalence in patients aged over 65 could be around 1.5%. Objective: describe demographic and clinical characteristics of patients older than 65 years of age with epilepsy. Materials and methods: A cross-sectional descriptive study was carried out in two high complexity hospitals in Bogotá, Colombia during 2005-2008. Demographic data were compiled and patients characterized regarding the type, frequency and diagnosis of seizures (based on ILAE classification), probable etiology, having a family background of epilepsy, and current pharmacological management. Results: 211 clinical histories were reviewed and 179 of them selected. Mean patient age was 75 (65-98) and average age at onset of epilepsy was 67.5 (7-93). 84% of the seizures were classified as being focal. The most frequently occurring diagnosis was symptomatic focal epilepsy (94.4%). 74 cases (41.3%) had an etiological diagnosis. The most important cause was cerebrovascular disease (61 patients). First generation anti-epileptic drugs were the most used ones (99%). 81/104 patients were found not to be free from epileptic episodes. Conclusions: Most seizures have a partial beginning, resulting from symptomatic partial epilepsy as a consequence of a vascular lesion. Pharmacological treatment must be considered following the first seizure. Treatment with second generation anti-epileptic drugs such as Lamotrigine, Gabapentin, Levetiracetam and Topiramate must be begun for minimizing secondary effects and low doses must be maintained from the start of treatment. Costs may limit the use of the above antiepileptic drugs, in such cases Phenytoin and Carbamazepine may be used with extreme caution

Profile of children and adolescents with autism spectrum disorders in an institution in Bogotá, Colombia

Objective: To determine the profile of children and adolescents diagnosed with autism spectrum disorder (ASD) in a comprehensive care centre in Bogota, Colombia. Material and methods: A descriptive-correlational study with a sample of patients who had attended the institution from 2003 to 2009. Demographic and clinical aspects were evaluated and a correlation between the diagnosis and severity being analysed in search for risk factors. Results: A total of 138 patients were studied. The average age of onset was 21 months, and diagnosis had been made at 45 months. There was a male predominance (6.15:1). The predominant diagnosis was autistic syndrome (83%), followed by pervasive developmental disorder not otherwise specified (17%). There was no pathological background in the family history, during pregnancy or during the neonatal period. Motor development during the first year was normal but acquisition of language skills was compromised. The specific signs of ASD as regards the disorder in itself, communication skills, spontaneous speech, verbal comprehension, attention, imitation, use of objects, self-care and symbolic play were significantly related to the severity of the disease. Conclusions: Diagnosis of ASD is still delayed in our population and usually after referral from someone other than a health professional. The most important problems were found in communication skills and relationships with peers. The study did not show significant associated risk factors. Resumen: Objetivo: Caracterizar la población de niños y adolescentes con diagnóstico de trastornos del espectro autista (TEA) en un centro de atención integral en Bogotá Colombia. Material y métodos: Estudio descriptivo-correlacional, de la población de pacientes que han asistido al centro desde el año 2003 hasta el 2009. Se evaluaron los aspectos demográficos y clínicos, y se realizó una correlación entre las variables con el diagnóstico y la severidad para la búsqueda de factores de riesgo. Resultados: Se estudió a 138 pacientes. La edad promedio de inicio fue a los 21 meses y el diagnóstico a los 45. Hubo predominancia masculina (6,15:1). El diagnóstico mas frecuente fue síndrome autista (83%), seguido por trastorno generalizado del desarrollo no determinado (17%). No se encontraron antecedentes importantes en la familia, durante el embarazo ni en el periodo neonatal. El desarrollo motor durante el primer año fue normal mientras que el desarrollo de la comunicación verbal se encontró comprometido. Los signos específicos de TEA como el trastorno en referencia a sí mismo, comunicación, habla espontánea, comprensión verbal, atención, imitación, utilización de objetos, autocuidado y juego simbólico se relacionaron significativamente con la severidad del cuadro. Conclusiones: El diagnostico de los TEA continúa siendo tardío en nuestra población y generalmente luego de la remisión de personal ajeno a la salud. Las alteraciones más importantes se encuentran en la comunicación y en la relación con los pares. En el estudio no se evidenciaron factores de riesgo que pudieran estar asociados. Keywords: Pervasive developmental disorder, Autism spectrum disorder, Autism, Risk factors, Neurological development, Palabras clave: Trastorno generalizado del desarrollo, Trastorno del espectro autista, Autismo, Factores de riesgo, Neurodesarroll

Caracterización de niños y adolescentes con trastornos del espectro autista en una institución de Bogotá, Colombia

Resumen: Objetivo: Caracterizar la población de niños y adolescentes con diagnóstico de trastornos del espectro autista (TEA) en un centro de atención integral en Bogotá Colombia. Material y métodos: Estudio descriptivo-correlacional, de la población de pacientes que han asistido al centro desde el año 2003 hasta el 2009. Se evaluaron los aspectos demográficos y clínicos, y se realizó una correlación entre las variables con el diagnóstico y la severidad para la búsqueda de factores de riesgo. Resultados: Se estudió a 138 pacientes. La edad promedio de inicio fue a los 21 meses y el diagnóstico a los 45. Hubo predominancia masculina (6,15:1). El diagnóstico mas frecuente fue síndrome autista (83%), seguido por trastorno generalizado del desarrollo no determinado (17%). No se encontraron antecedentes importantes en la familia, durante el embarazo ni en el periodo neonatal. El desarrollo motor durante el primer año fue normal mientras que el desarrollo de la comunicación verbal se encontró comprometido. Los signos específicos de TEA como el trastorno en referencia a sí mismo, comunicación, habla espontánea, comprensión verbal, atención, imitación, utilización de objetos, autocuidado y juego simbólico se relacionaron significativamente con la severidad del cuadro. Conclusiones: El diagnostico de los TEA continúa siendo tardío en nuestra población y generalmente luego de la remisión de personal ajeno a la salud. Las alteraciones más importantes se encuentran en la comunicación y en la relación con los pares. En el estudio no se evidenciaron factores de riesgo que pudieran estar asociados. Abstract: Objective: To determine the profile of children and adolescents diagnosed with autism spectrum disorder (ASD) in a comprehensive care centre in Bogota, Colombia. Material and methods: A descriptive-correlational study with a sample of patients who had attended the institution from 2003 to 2009. Demographic and clinical aspects were evaluated and a correlation between the diagnosis and severity being analysed in search for risk factors. Results: A total of138 patients were studied. The average age of onset was 21 months, and diagnosis had been made at 45 months. There was a male predominance (6.15:1). The predominant diagnosis was autistic syndrome (83%), followed by pervasive developmental disorder not otherwise specified (17%). There was no pathological background in the family history, during pregnancy or during the neonatal period. Motor development during the first year was normal but acquisition of language skills was compromised. The specific signs of ASD as regards the disorder in itself, communication skills, spontaneous speech, verbal comprehension, attention, imitation, use of objects, self-care and symbolic play were significantly related to the severity of the disease. Conclusions: Diagnosis of ASD is still delayed in our population and usually after referral from someone other than a health professional. The most important problems were found in communication skills and relationships with peers. The study did not show significant associated risk factors. Palabras clave: Trastorno generalizado del desarrollo, Trastorno del espectro autista, Autismo, Factores de riesgo, Neurodesarrollo, Keywords: Pervasive developmental disorder, Autism spectrum disorder, Autism, Risk factors, Neurological developmen

Evaluating executive function in schoolchildren with symptoms of attention deficit hyperactivity disorder

Objective: To identify impairment of executive functions (EFs) in children with attention deficit hyperactivity disorder (ADHD). Subjects and methods: A case-control study was performed on a sample of schoolchildren with low socioeconomic levels in Bogota, Colombia. ADHD was diagnosed using the DSM IV checklist and the Behaviour Assessment System for Children (BASC) scale. Children with cognitive deficits were excluded. We evaluated scores from six measurements of EF. We conducted a bivariate statistical analysis to compare the variables, a multivariate study controlled by sex and age, and a logistic regression analysis. Results: The study sample included 119 children with ADHD and 85 controls, all aged between 6 and 12 years. Controlling by sex, age, and type of school showed that EF measurements in children with ADHD were significantly more impaired than in controls, especially for measurements of verbal and graphic fluency, Rey-Osterrieth complex figure, and cognitive flexibility. Comparison of ADHD subgroups showed that results in children with multiple deficits were similar to those in the global ADHD group. Graphic fluency impairment was the sole impairment in cases with only attention deficit or only hyperactivity-impulsivity manifestations. Conclusions: EF measures in children with ADHD revealed more problems, particularly those having to do within planning, inhibition, working memory and cognitive control. Age and sex may affect the degree of EF impairment. Resumen: Objetivo: Determinar las alteraciones de las funciones ejecutivas (FE) en niños con trastorno por déficit de atención e hiperactividad (TDAH). Sujetos y métodos: Se realizó un estudio de casos y controles con una muestra de estudiantes de colegios de Bogotá, Colombia, pertenecientes a los estratos socioeconómicos bajos. El diagnóstico de TDAH se realizó con la lista de chequeo del DSM IV y la escala multidimensional de BASC. Se descartaron los niños que presentaban trastornos cognitivos. Se evaluó el desempeño en 6 medidas de funciones ejecutivas. Se realizaron un análisis bivariado entre variables, un estudio multivariado controlado por sexo y edad, y una regresión logística condicional. Resultados: Se estudió a 119 niños con síntomas de TDAH y 85 controles con edades comprendidas entre 6 y 13 años. Cuando se controlaron por sexo, edad y tipo de colegio, los niños con TDAH tuvieron un mayor compromiso que los controles en las medidas de FE correspondientes a fluidez verbal y gráfica, figura compleja de Rey-Osterrieth y flexibilidad cognitiva. Cuando se compararon los subgrupos de TDAH, no hubo diferencias entre el grupo mixto con el general. Los casos con inatención sola e hiperactividad-impulsividad sola presentaron dificultades en fluidez gráfica. Conclusiones: Los niños con síntomas de TDAH presentan mayores problemas en medidas de las FE especialmente en planeación, inhibición, memoria de trabajo y control cognitivo. Parece existir posiblemente una heterogeneidad entre el trastorno de las FE respecto del sexo y la edad. Keywords: Attention, Attention deficit hyperactivity disorder, Executive functions, Behavioural Assessment System for Children, Neuropsychological assessment of children, Weschler Intelligence Scale for Children-Revised, Palabras clave: Atención, Trastorno por déficit de atención e hiperactividad, Funciones ejecutivas, Sistema de evaluación de la conducta en niños, Evaluación neuropsicológica infantil, Weschler inteligence scale for children-revise

Evaluación de la función ejecutiva en una población escolar con síntomas de déficit de atención e hiperactividad

Resumen: Objetivo: : Determinar las alteraciones de las funciones ejecutivas (FE) en niños con trastorno por déficit de atención e hiperactividad (TDAH). Sujetos y métodos: Se realizó un estudio de casos y controles con una muestra de estudiantes de colegios de Bogotá, Colombia, pertenecientes a los estratos socioeconómicos bajos. El diagnóstico de TDAH se realizó con la lista de chequeo del DSM IV y la escala multidimensional de BASC. Se descartaron los niños que presentaban trastornos cognitivos. Se evaluó el desempeño en 6 medidas de funciones ejecutivas. Se realizaron un análisis bivariado entre variables, un estudio multivariado controlado por sexo y edad, y una regresión logística condicional. Resultados: Se estudió a 119 niños con síntomas de TDAH y 85 controles con edades comprendidas entre 6 y 13 años. Cuando se controlaron por sexo, edad y tipo de colegio, los niños con TDAH tuvieron un mayor compromiso que los controles en las medidas de FE correspondientes a fluidez verbal y gráfica, figura compleja de Rey-Osterrieth y flexibilidad cognitiva. Cuando se compararon los subgrupos de TDAH, no hubo diferencias entre el grupo mixto con el general. Los casos con inatención sola e hiperactividad-impulsividad sola presentaron dificultades en fluidez gráfica. Conclusiones: Los niños con síntomas de TDAH presentan mayores problemas en medidas de las FE especialmente en planeación, inhibición, memoria de trabajo y control cognitivo. Parece existir posiblemente una heterogeneidad entre el trastorno de las FE respecto del sexo y la edad. Abstract: Objective: To identify impairment of executive functions (EF) in children with attention deficit hyperactivity disorder (ADHD). Subjects and methods: A case-control study was performed on a sample of schoolchildren with low socioeconomic levels in Bogota, Colombia. ADHD was diagnosed using the DSM IV checklist and the Behavior Assessment System for Children scale. Children with cognitive deficits were excluded. We evaluated scores from six measurements of executive function (EF). We conducted a bivariate statistical analysis to compare the variables, a multivariate study controlled by sex and age, and a logistic regression analysis. Results: The study sample included 119 children with ADHD and 85 controls, all aged between 6 and 12 years. Controlling by sex, age, and type of school showed that EF measurements in children with ADHD were significantly more impaired than in controls, especially for measurements of verbal and graphic fluency, Rey-Osterrieth Complex Figure, and cognitive flexibility. Comparison of ADHD subgroups showed that results in children with multiple deficits were similar to those in the global ADHD group. Graphic fluency impairment was the sole impairment in cases with only attention deficit or only hyperactivity-impulsivity manifestations. Conclusions: EF measures in children with ADHD revealed more problems, particularly those having to do within planning, inhibition, working memory and cognitive control. Age and sex may affect the degree of EF impairment. Palabras clave: Atención, Trastorno por déficit de atención e hiperactividad, Funciones ejecutivas, Sistema de evaluación de la conducta en niños, Evaluación neuropsicológica infantil, Weschler inteligence scale for children-revised, Key words: Attention, Attention deficit hyperactivity disorder, Executive functions, Behavioral assessment system for children, Neuropsychological assessment of children, Weschler inteligence scale for children-revise