RESUMEN
A high body mass index (BMI) is commonly used as an index of overweight and obesity. There is persistent evidence of high heritability for variation in BMI, but the effects of common environment appear inconsistent across different European countries. Our objective was to compare genetic and environmental effects on BMI in a sample of twins from two different European countries with distinct population and cultural backgrounds. We analysed data of adult female twins from the Netherlands Twin Register (222 monozygotic [MZ] and 103 dizygotic [DZ] pairs) and the Murcia Twin Register (Spain; 202 MZ and 235 DZ pairs). BMI was based on self-reported weight and height. Dutch women were taller and heavier, but Spanish women had a significantly higher mean BMI. The age related weight increase was significantly stronger in the Spanish sample. Genetic analyses showed that genetic factors are the main contributors to variation in height, weight, and BMI, within both countries. For height and weight, estimates of genetic variances did not differ, but for height, the estimate for the environmental variance was significantly larger in Spanish women. For BMI, both the genetic and the environmental variance components were larger in Spanish than in Dutch women.
Asunto(s)
Índice de Masa Corporal , Carácter Cuantitativo Heredable , Adulto , Estatura/genética , Peso Corporal/genética , Femenino , Variación Genética , Humanos , Países Bajos , Sistema de Registros , España , Gemelos Dicigóticos , Gemelos MonocigóticosRESUMEN
AIM: To review the studies on brain mechanisms in decision making within the framework of the somatic marker hypothesis, and based on experiments employing the Iowa Gambling Task. DEVELOPMENT: An overview of the somatic marker hypothesis is presented together with the review of the main results obtained from research in brain damaged patients, and normal subjects with functional neuroimaging studies, that have led to the identification of the neural structures involved in decision making in humans. CONCLUSIONS: The main region involved in decision making is the ventromedial prefrontal cortex, that integrates sensory, mnesic and emotional information relevant to the task. Other structures intervening in the various relevant processes in decision making are the amygdala (processing and encoding of the emotional signal and its association with contextual stimuli) and the cingulate cortex (process monitoring and response inhibition, especially in situations of uncertainty). The prefrontal dorsolateral cortex would also be involved through the necessary activation of the working memory in the decision making process, especially in the case of complex tasks.
Asunto(s)
Encéfalo , Toma de Decisiones , Encéfalo/anatomía & histología , Encéfalo/fisiología , Humanos , Memoria/fisiología , Modelos Neurológicos , Pruebas NeuropsicológicasRESUMEN
Objetivo. Revisar los estudios sobre los mecanismos cerebrales de la toma de decisiones en el marco de la hipótesis del marcador somático y basados experimentalmente en el empleo dela tarea de apuestas de Iowa (Iowa Gambling Task). Desarrollo. Se presenta la teoría del marcador somático y las características de la citada tarea de toma de decisiones y otras relacionadas. A continuación, se revisan los principales estudios llevados a cabo en personas con lesión cerebral y los procedentes de sujetos normales, con el empleo de neuroimagen funcional, que han hecho posible la identificación de las estructuras neurales implicadas en la toma de decisiones en humanos. Conclusiones. La principal región implicada es la corteza prefrontal ventromedial, donde se produce la integración de la información sensorial, amnésica y emocional necesaria para la tarea. Otras estructuras que intervienen en diferentes procesos relevantes para la toma de decisiones serían la amígdala (procesamiento y codificación de la señal emocional y su asociación con estímulos contextuales) y la corteza cingulada (monitorización del proceso e inhibición de respuesta, especialmente en situaciones de incertidumbre). La corteza prefrontal dorso lateral también participaría en este proceso debido a la necesaria activación de la memoria de trabajo en la toma de decisiones, en especial cuando la tarea es compleja (AU)
Aim. To review the studies on brain mechanisms in decision making within the framework of the somatic marker hypothesis, and based on experiments employing the Iowa Gambling Task. Development. An overview of the somatic marker hypothesis is presented together with the review of the main results obtained from research in brain damaged patients, and normal subjects with functional neuroimaging studies, that have led to the identification of the neural structures involved indecision making in humans. Conclusions. The main region involved in decision-making is the ventromedial prefrontal cortex, that integrates sensory, mnesic and emotional information relevant to the task. Other structures intervening in the various relevant processes in decision-making are the amygdala (processing and encoding of the emotional signal and its association with contextual stimuli) and the cingulate cortex (process monitoring and response inhibition, especially in situations of uncertainty). The prefrontal dorsolateral cortex would also be involved through the necessary activation of the working memory in the decision making process, especially in the case of complex tasks (AU)
Asunto(s)
Humanos , Toma de Decisiones , Amígdala del Cerebelo/fisiología , Corteza Prefrontal/fisiología , Telencéfalo/fisiología , Imagen por Resonancia MagnéticaRESUMEN
The authors investigated the role of the frontal lobes in the emotional response in 19 patients with brain damage and 23 control subjects. They studied the modulation of the startle blink reflex by affective pictures, and other autonomic responses. Patients showed a dissociation between the startle reflex and the affective valence ratings of the pictures, as a result of a low inhibition of the startle reflex by pleasant pictures. Pictures elicited lower skin conductance responses (SCRs) in patients than in controls, whereas the groups did not differ in the SCRs prompted by less significant acoustic stimuli. The findings point to the frontal lobe as a structure involved in the emotional response and in the physiological emotional arousal related to the complexity of the stimuli.
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Síntomas Afectivos/fisiopatología , Lesiones Encefálicas/psicología , Emociones/fisiología , Lóbulo Frontal/patología , Lóbulo Frontal/fisiología , Estimulación Acústica , Adulto , Parpadeo , Lesiones Encefálicas/complicaciones , Estudios de Casos y Controles , Femenino , Respuesta Galvánica de la Piel , Humanos , Masculino , Persona de Mediana Edad , Estimulación Luminosa , Reflejo de SobresaltoRESUMEN
BACKGROUND: To asses if the hot flushes during the menopause are associated to alterations in the metabolism of nitric oxide, total antioxidant activity and other biochemical parameters. To evaluate the effect of hormone replacement therapy (HRT) in the metabolism of nitric oxide, total antioxidant activity and biochemistry in menopausal women with and without hot flushes. PATIENTS AND METHODS: Experimental study. This study included 29 healthy menopausal women with hot flushes (12 with HRT) and 20 without them (6 with HRT), 45-55 years old, with duration of menopause ranging from 1 to 5 years. Control group included 14 fertile women. Determinations of estradiol, nitrite-nitrate, total antioxidant activity and basic analytic, were performed before previous and after 4-6 month of HRT therapy. RESULTS: Previously to HRT, hot flushes were associated to smaller level of total antioxidant activity (p < 0.05) in plasma, without differences in nitrite-nitrate concentrations. HRT was associated to increase in total antioxidant activity level and nitrite-nitrate concentrations (p < 0.05) in menopausal women, with and without hot flushes. CONCLUSIONS: Hot flushes during the menopause indicate a high level of oxidative stress and a higher cardiovascular risk. HRT decreased the oxidative stress level and increased the nitric oxide derivate metabolites in menopausal women with and without hot flushes.
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Terapia de Reemplazo de Estrógeno , Sofocos/metabolismo , Menopausia/efectos de los fármacos , Menopausia/metabolismo , Óxido Nítrico/metabolismo , Adulto , Análisis de Varianza , Antioxidantes/metabolismo , Bilirrubina/sangre , Glucemia/metabolismo , Enfermedades Cardiovasculares/prevención & control , Colesterol/sangre , Estradiol/administración & dosificación , Estradiol/sangre , Femenino , Estudios de Seguimiento , Humanos , Acetato de Medroxiprogesterona/administración & dosificación , Persona de Mediana Edad , Nitratos/sangre , Óxido Nítrico/sangre , Nitritos/sangre , Estrés Oxidativo , Congéneres de la Progesterona/administración & dosificación , Factores de Riesgo , Albúmina Sérica/metabolismo , Factores de Tiempo , Triglicéridos/sangreAsunto(s)
Terapia de Reemplazo de Estrógeno , Menopausia , Recolección de Datos , Estradiol/uso terapéutico , Terapia de Reemplazo de Estrógeno/efectos adversos , Femenino , Humanos , Acetato de Medroxiprogesterona/uso terapéutico , Persona de Mediana Edad , Aceptación de la Atención de Salud , Atención Primaria de Salud , Medición de RiesgoRESUMEN
The elicitation and habituation of electrodermal orienting responses to auditory stimuli of 19 children with Down syndrome and a control group, an age and sex-matched sample of children without mental retardation were compared. Stimuli were ten 2-second 80 dB, 1000 Hz tones followed by a test tone (80 dB, 500 Hz). Children with Down syndrome gave electrodermal orienting responses of a lower amplitude than did the children in the control group. Both groups showed habituation of their responses. No significant differences were found between groups in either skin conductance levels or frequency of nonspecific responses. Overall, children with Down syndrome showed electrodermal hyporesponsivity in their orienting responses to the stimuli.
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Nivel de Alerta , Atención , Síndrome de Down/psicología , Respuesta Galvánica de la Piel , Estimulación Acústica , Adolescente , Niño , Femenino , Habituación Psicofisiológica , Humanos , Percepción Sonora , Masculino , Percepción de la Altura TonalRESUMEN
The effects of two types of laboratory stressors, a structured interview and the cold pressor test, on blood pressure (BP) and heart rate (HR) were studied in normotensive individuals (n = 16), unmedicated hypertensive patients (n = 12), and medicated hypertensive patients (n = 46). Fifteen patients were in the bisoprolol group, 16 patients were in the enalapril group, and 15 patients were in the nitrendipine group. Concurrent physiologic measures, finger pulse volume (FPV), electrodermal activity, and respiratory frequency (RF), were also used to evaluate the level of stress reached by the subjects during and after the tasks. No significant differences were evident between the different treatments in BP and other physiologic responses to stressors. Patients receiving bisoprolol maintained lower HR and systolic BP values, but these differences were not related to the reaction to the stressors. No significant differences were noted in diastolic BP (DBP) between the different groups. The highest physiologic responses were obtained during the structured interview. Antihypertensive monotherapy does not attenuate cardiovascular reactions induced by acute stress in controlled laboratory conditions. In laboratory studies of the relationships between stress and hypertension, it is important that social stressors be used and that physiologic rather than cardiovascular measures of stress be recorded.
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Antihipertensivos/uso terapéutico , Presión Sanguínea , Frecuencia Cardíaca , Hipertensión/fisiopatología , Estrés Fisiológico/fisiopatología , Adulto , Anciano , Bisoprolol/uso terapéutico , Presión Sanguínea/efectos de los fármacos , Electrofisiología , Enalapril/uso terapéutico , Femenino , Respuesta Galvánica de la Piel/efectos de los fármacos , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Hipertensión/complicaciones , Hipertensión/tratamiento farmacológico , Masculino , Persona de Mediana Edad , Nitrendipino/uso terapéutico , Pulso Arterial/efectos de los fármacos , Estrés Fisiológico/complicacionesAsunto(s)
Antihipertensivos/administración & dosificación , Presión Sanguínea , Hipertensión/tratamiento farmacológico , Estrés Psicológico/complicaciones , Adulto , Anciano , Presión Sanguínea/efectos de los fármacos , Femenino , Humanos , Hipertensión/complicaciones , Hipertensión/fisiopatología , Masculino , Persona de Mediana EdadRESUMEN
Electrodermal activity (EDA) changes in menstrual cycle were studied in two experiments. In both experiments subjects were presented with 16 80-dB tones; 15 tones were 4 s, 1000 Hz, and the last one - change trial - was a 6-s, 3000-Hz tone. In Expt. 1, a within-subjects design was employed, and 15 women were studied throughout a complete menstrual cycle. No significant changes in EDA associated with menstrual cycle phases were found, but significant decreases in electrodermal responsiveness during experimental sessions in EDA parameters were observed. In Expt. 2, with a between-subjects design, 56 women were divided in menstrual (n = 10), follicular (n = 12), ovulatory (n = 14), luteal (n = 13) and premenstrual (n = 7) groups, according to the cycle phase in which the subject was at the time of recording. At the ovulatory phase there were significant increases in skin conductance response (SCR) magnitude, skin conductance level, SCR habituation rate, and SCR amplitude to stimulus change, in relation to menstrual, luteal, and premenstrual phases. The discrepancies in the EDA data coming from the two experiments may be explained by practice effects appearing in Expt. 1.
Asunto(s)
Respuesta Galvánica de la Piel , Ciclo Menstrual/fisiología , Adulto , Femenino , HumanosRESUMEN
Changes in electrodermal activity and subjective experience were studied during the menstrual cycle. Sixty-two women, grouped into menstrual, follicular, ovulatory, luteal and premenstrual phases, were presented with 15, 4-s, 80-dB, 1000-Hz tones. Psychological states and psychosomatic symptoms were tested with Spielberger's State-Trait Anxiety Inventory and a self-report questionnaire. Two estimation procedures of the hormonal phases were used: one based on the onset of menses and cycle length, and another on the basal body temperature. Subjects were grouped into low or high levels of luteinizing hormone, follicle-stimulating hormone and progesterone. There were significant increases in nonspecific response frequency, skin conductance response magnitude, skin conductance level, and a decrease in habituation rate at the ovulatory phase in comparison with luteal and premenstrual phases. No changes between the cycle phases were found in subjective experience. High follicle-stimulating hormone levels were associated with slower habituation rates and low trait-anxiety. The relationship between arousal changes and subjective experience in menstrual cycle is discussed.
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Nivel de Alerta/fisiología , Hormona Folículo Estimulante/sangre , Respuesta Galvánica de la Piel/fisiología , Hormona Luteinizante/sangre , Ciclo Menstrual/fisiología , Progesterona/sangre , Adulto , Regulación de la Temperatura Corporal/fisiología , Femenino , Habituación Psicofisiológica/fisiología , HumanosRESUMEN
The present study was aimed at replicating the results of a previous work on sex differences and electrodermal asymmetry from our laboratory (Román, et al. 1987). Skin conductance was bilaterally recorded in a sample of 44 dextral volunteers (22 males and 22 females) during a stimulus-free period, and the performance of two tasks (verbal and spatial). Subjects were grouped into two groups of right-hand and left-hand dominance in their electrodermal responses (EDRs) in accordance with their laterality coefficient scores at rest. During the tasks subjects appeared clearly differentiated by their lateralization in the magnitude and frequency of EDRs independently of gender: right-hand responders showed higher electrodermal activity on their right hand, while left-hand responders showed higher electrodermal activity on their left hand. Sex differences were not observed within each responsiveness pattern. The orientation of phasic electrodermal changes remained constant throughout the different conditions.
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Nivel de Alerta , Dominancia Cerebral , Respuesta Galvánica de la Piel , Adolescente , Adulto , Femenino , Lateralidad Funcional , Humanos , Masculino , Factores SexualesRESUMEN
Phasic electrodermal conductance responses were bilaterally recorded from 30 subjects (15 males and 15 females). After a 5-min adaptation period subjects were presented with two series of ten 80-dB tones each, with a 4-min rest period between the two series. Data from sinistrals, ambidextrous, and from subjects with familial sinistrality were excluded from statistical analysis. Males displayed more asymmetry between hands both in their non-specific and specific responses, with larger skin conductance responses on the left hand. Females showed a less marked asymmetry, with larger skin conductance responses on the right hand. Similar results were found in skin conductance levels. It was concluded that sex differences are an important variable in the study of electrodermal asymmetry.
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Vías Auditivas/fisiología , Lateralidad Funcional/fisiología , Respuesta Galvánica de la Piel/fisiología , Caracteres Sexuales , Estimulación Acústica , Adulto , Femenino , Mano/inervación , Humanos , MasculinoRESUMEN
The purpose of this paper is to examine the relationship between the general processes of arousal and sensitization and the response increment processes at the cellular level, which have been considered as model systems of behavioural plasticity, i.e. the kindling effect and long-term potentiation in hippocampal pathways. From the published literature it appears that kindling and potentiation may be considered as model systems of sensitization and arousal. Moreover, research on these potentiation effects gives support to the hypothesis of specific arousal systems in the brain which mediate learning and memory. It is proposed that a multidisciplinary approach, including data from behavioural neurobiology and from psychophysiological studies, can contribute to better knowledge of the biological basis of learning.
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Nivel de Alerta/fisiología , Conducta/fisiología , Excitación Neurológica , Aprendizaje/fisiología , Animales , Humanos , PsicofisiologíaRESUMEN
The effects of the activation level and subject's sex on bilateral skin conductance measures were studied. Thirty right-handed subjects (15 males and 15 females) were exposed to three types of stimulus conditions: rest-period, verbal task and spatial task. Results showed that no relationship was observed between EDA asymmetry and the increase in the activation level induced by the verbal and the spatial tasks. Males showed both higher SCRs and greater frequency of responses on the left than on the right hand. The direction of electrodermal asymmetry remained constant regardless of the stimulus conditions. It was concluded that sex differences are important in the study of EDA asymmetry and that this asymmetry appeared to depend on peripheral variations.