RESUMEN
Clinical research suggests that individuals with major depressive disorder (MDD) are cognitively inflexible, exhibiting ruminative, rigid, and automatic thoughts within a negative schema. However, existing neuropsychological research on cognitive flexibility in this population has not employed emotional stimuli. Because research suggests that the performance of individuals with MDD is modulated when emotional stimuli are used, this study investigates the impact of emotional stimuli on cognitive flexibility performance through a novel emotional modification of the Wisconsin Card Sorting Test. Controls were less flexible when stimuli were positive and individuals with MDD were less flexible when stimuli were negative relative to the controls. These divergent styles of responding to emotional information may contribute to the relative risk or protection from depressed mood.
Asunto(s)
Atención , Concienciación , Cognición , Trastorno Depresivo Mayor/psicología , Emociones , Reconocimiento Visual de Modelos , Semántica , Disposición en Psicología , Adulto , Afecto , Nivel de Alerta , Percepción de Color , Mecanismos de Defensa , Aprendizaje Discriminativo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Valores de Referencia , PensamientoRESUMEN
Evidence of a right-posterior brain anomaly was found in a study of 19 individuals with major depression and 15 controls. Participants performed a recognition-memory task involving positive, neutral, and negative face and word stimuli. Scalp brain wave topography suggested a region-specific anomaly in the depressed group. Individuals with major depression demonstrated a reduction in the N200 component of the event-related brain potential to faces and not words. Furthermore, results indicate that the regional anomaly is specific to positive facial stimuli. Findings are interpreted in light of a model of regional brain specialization in emotion and psychopathology.
Asunto(s)
Encéfalo/fisiopatología , Trastorno Depresivo Mayor/fisiopatología , Trastorno Depresivo Mayor/psicología , Dominancia Cerebral , Potenciales Evocados Auditivos , Potenciales Evocados Visuales , Adulto , Afecto , Estudios de Casos y Controles , Electroencefalografía , Expresión Facial , Femenino , Humanos , Masculino , Modelos Neurológicos , Periodo Refractario Electrofisiológico , Pruebas de Asociación de PalabrasRESUMEN
Previous event-related brain potential (ERP) research has found that dysthymic subjects differ from control subjects during later stages of information processing. An important issue that emerges from this literature is whether differences found in these ERP components, typically associated with cognitive processing, can be attributed to earlier differences in basic perceptual processing. This study was undertaken to determine whether early processing deficits are apparent in dysthymic persons. Responses of dysthymics (n = 23) were compared with those of anhedonic (n = 15) and normal control (n = 17) subjects. ERPs were recorded while subjects heard tones at 55, 65, 75, 85, and 95 dB. Overall, N1-P1 and N1-P2 components of the ERP increased in a strong linear fashion as stimulus intensity increased. Dysthymics did exhibit a smaller N1-P2 response than normal subjects, which suggests the presence of difficulties in initial perceptual processing.
Asunto(s)
Síntomas Afectivos/fisiopatología , Nivel de Alerta/fisiología , Atención/fisiología , Depresión/fisiopatología , Electroencefalografía , Potenciales Evocados Auditivos/fisiología , Adulto , Síntomas Afectivos/diagnóstico , Síntomas Afectivos/psicología , Corteza Cerebral/fisiopatología , Depresión/diagnóstico , Depresión/psicología , Femenino , Humanos , Masculino , Percepción de la Altura Tonal/fisiologíaRESUMEN
Mood-congruent working memory biases were examined in a delayed matching to sample paradigm using the slow wave (SW) event-related brain potential (ERP) component. Mood-congruent working memory biases, indexed by SW amplitudes, were demonstrated among individuals experiencing a major depressive episode (MDE) and nondepressed controls but not individuals with dysthymia. However, analyses of symptom severity demonstrated that those with dysthymia exhibited significantly less negative SW amplitudes with increasing depressive mood severity, whereas individuals with major depression demonstrated more negative SW amplitudes with increasing depressive mood severity. These results are discussed in the context of diagnostic specificity for cognitive biases associated with working memory of mood-disordered individuals.
Asunto(s)
Electroencefalografía , Trastornos de la Memoria/diagnóstico , Trastornos de la Memoria/etiología , Trastornos del Humor/psicología , Adulto , Electrooculografía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Tiempo de Reacción , Índice de Severidad de la EnfermedadRESUMEN
The high comorbidity of depression and anxiety is well established empirically but not well understood conceptually, in terms of either psychological or biological mechanisms. A neuropsychological model of regional brain activity in emotion provides contrasting hypotheses for depression and anxiety, with depression associated with a relative decrease and anxiety with a relative increase in right-posterior activity. These hypotheses received support in a comparison of individuals diagnosed with depression and community controls, and also in a separate study of nonpatients administered a measure of perceptual asymmetry. Hierarchical regressions revealed that depression and anxiety were uniquely and jointly associated with perceptual asymmetry. In light of consistent empirical support for the model, implications for conceptualizations of the comorbidity of depression and anxiety are discussed.
Asunto(s)
Ansiedad/fisiopatología , Encéfalo/fisiopatología , Depresión/fisiopatología , Trastorno Depresivo/diagnóstico , Trastorno Depresivo/fisiopatología , Dominancia Cerebral , Adulto , Ansiedad/complicaciones , Estudios de Casos y Controles , Depresión/complicaciones , Femenino , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Modelos Neurológicos , Pruebas Neuropsicológicas , Escalas de Valoración PsiquiátricaRESUMEN
Light therapy in patients with seasonal affective disorder has been reported to enhance visual P300 amplitude. This findings raises the possibility that variations in P300 occur naturally in nonpatients as a function of seasonal variation in sunlight. In the present investigation, P300 was studied in a sample of psychiatrically screened normal subjects who were tested at different times of the year. P300 was larger in women than men and varied in relation to season. This pattern is relevant to studies in which subjects are tested under varying sunlight conditions, such as different seasons. In addition, variations in P300 in normal subjects may be relevant to an understanding of the effectiveness of light therapy for patients with seasonal affective disorder.
Asunto(s)
Nivel de Alerta/fisiología , Atención/fisiología , Potenciales Evocados Auditivos/fisiología , Potenciales Evocados Visuales/fisiología , Luz , Estaciones del Año , Adulto , Corteza Cerebral/fisiopatología , Electroencefalografía , Femenino , Humanos , Masculino , Reconocimiento Visual de Modelos/fisiología , Discriminación de la Altura Tonal/fisiología , Valores de Referencia , Trastorno Afectivo Estacional/fisiopatologíaRESUMEN
Research utilizing visual event-related brain potentials (ERPs) has demonstrated that reduced P300 amplitude and prolonged latency may qualify as a biological marker (biomarker) for schizophrenia (SZ). We examined P300 characteristics in response inhibition among three putatively distinct psychopathology groups including schizophrenia (SZ), bipolar I disorder (BD) and schizoaffective disorder (SA) in comparison with healthy controls (CT) to determine their electrophysiological distinctiveness. In two separate studies, deficits in response inhibition indexed by the P300 component were investigated using a lateralized Go/NoGo task. We hypothesized that deficits in response inhibition would be present and distinctive among the groups. In both studies, SZ showed response inhibition deficits as measured by P300 when stimuli were presented to the right visual field. In Study 2, delayed cognitive stimulus evaluation was observed in BD as indexed by prolonged P300 latency for NoGo trials. Six selected NoGo P300 variables out of thirty six NoGo P300 variables (18 amplitude, 18 latency) correctly classified SZ (79%), SA (64%) in Study 1 and seven variables selected in Study 2 classified CT (80%), and SZ (61%), BD (67%) and CT (68%) with the accuracy higher than chance level (33%). The findings suggest that distinct P300 features in response inhibition may be biomarkers with the capacity to distinguish BD and SZ, although SA was not clearly distinguishable from SZ and CT.