RESUMEN
This paper reviews the literature concerning executive control impairments in degenerative dementias. The construct of executive control functioning is examined, as is the neuroanatomy of frontal-subcortical networks, believed to underlie executive function (EF) impairments. The pattern of EF impairments in Alzheimer's disease (AD) which affects temporal and parietal brain regions most severely is contrasted with observed executive dysfunctions in patients with dementias involving degeneration of primarily frontal and frontal-subcortical brain areas. EF impairments are present in each of these types of dementing illnesses. Although EF impairments are present in AD, they are less prominent than the memory disorder in the neuropsychological profile of the disease and tend to become more pronounced later in the course of the illness. In contrast, patients with frontal or frontal-subcortical dementia may demonstrate executive dysfunction, which occurs earlier in the disease progression and may be initially more severe.
Asunto(s)
Encéfalo/patología , Trastornos del Conocimiento/diagnóstico , Demencia/diagnóstico , Demencia/psicología , Trastornos de la Memoria/diagnóstico , Enfermedades Neurodegenerativas/diagnóstico , Enfermedades Neurodegenerativas/psicología , Atención , Encéfalo/anatomía & histología , Encéfalo/fisiopatología , Trastornos del Conocimiento/fisiopatología , Trastornos del Conocimiento/psicología , Demencia/patología , Demencia/fisiopatología , Diagnóstico Diferencial , Humanos , Trastornos de la Memoria/fisiopatología , Trastornos de la Memoria/psicología , Modelos Neurológicos , Trastornos del Movimiento/patología , Trastornos del Movimiento/psicología , Red Nerviosa , Enfermedades Neurodegenerativas/complicaciones , Enfermedades Neurodegenerativas/patología , Pruebas Neuropsicológicas , Índice de Severidad de la Enfermedad , Controles Informales de la Sociedad , VoliciónRESUMEN
Two studies of the relationship between depression and resting frontal electroencephalographic (EEG) activity are reported. Although considerable research supports the theory of left and right hemispheric specialization for approach and withdrawal behaviors, only four studies involving clinically depressed individuals have been published to date. Despite methodological similarities with published research, no significant differences in frontal activation emerged between depressed and nondepressed participants with either college students having high Beck Depression Inventory scores (Study 1) or with individuals diagnosed with DSM-III-R depression (Study 2). Post hoc analyses in Study 2 revealed one effect confined to lateral frontal leads during the first 2 min of EEG data; this finding was significant in only one of three reference montages. Results are discussed in light of methodological considerations and mediating variables such as temperament and coping styles.