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BACKGROUND: Bipolar disorder (BD) and schizophrenia (SCZ) may exhibit functional abnormalities in several brain areas, including the medial temporal and prefrontal cortex and hippocampus; however, a less explored topic is how brain connectivity is linked to premorbid trauma experiences and clinical features in non-Caucasian samples of SCZ and BD. METHODS: Sixty-two individuals with SCZ (n = 20), BD (n = 21), and healthy controls (HC, n = 21) from indigenous and African ethnicity were submitted to clinical screening (Di-PAD), traumata experiences (ETISR-SF), cognitive and functional MRI assessment. The item psychosis/hallucinations in SCZ patients showed a negative correlation with the global efficiency (GE) in the right dorsal attention network. The items mania, irritable mood, and racing thoughts in the Di-PAD scale had a significant negative correlation with the GE in the parietal right default mode network. CONCLUSIONS: Differences in the activation of specific networks were associated with earlier disease onset, history of physical abuse, and more severe psychotic and mood symptoms in SCZ and BD subjects of indigenous and black ethnicity. Findings provide further evidence on SZ and BD's brain connectivity disturbances, and their clinical significance, in non-Caucasian samples.

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La investigación sobre la conciencia desde una perspectiva neurobiológica constituye uno de los temas más controvertidos en el amplio dominio de las neurociencias. Tradicionalmente, la conciencia ha sido entendida como la experiencia subjetiva y privada que surge de la actividad de neuronas múltiples y que incluye nuestros pensamientos, recuerdos y lo imaginado. A menudo se hace la distinción entre una conciencia intransitiva, que alude a un estado de vigilancia opuesto al estado de coma clínico, y una transitiva, que se refiere al acceso consciente de diferentes piezas de información. Evolutivamente, al entender la conciencia como el resultado de habilidades cognitivas complejas, es posible plantear que ella se encuentra distribuida en la filogenia incluso más allá de los mamíferos sociales. A partir de la relación entre conciencia y cognición, dos teorías han sido ampliamente difundidas y debatidas: la del núcleo dinámico y la del espacio de trabajo global. La primera relaciona la experiencia consciente con circuitos tálamo-corticales recurrentes, mientras que la segunda considera vastas redes neuronales parieto-temporales y prefrontales como base para el acceso consciente. Se ha postulado que la conciencia depende de la actividad de una red neural por defecto. Aún más, la conciencia humana representaría una corriente narrativa cuya historia ha sido modulada por la interacción social.

Research about consciousness from a neurobiological perspective is one of the most controversial issues in the broad domain of neuroscience. Traditionally, consciousness has been defined as subjective and private experience that arises from multiple neuronal activities and it includes our thoughts, memories and imaging. Usually, it has been made a distinction between intransitive consciousness that refers to a vigilance state opposite to clinical coma and transitive consciousness conceived as a conscious access to different pieces of information. From an evolutionary perspective, consciousness may be conceived as the result of complex cognitive skills leading to claim that it is distributed in phylogeny even beyond social mammals. From the relationship between consciousness and cognition, two theories have been widely discussed: the Dynamic Core and the Global Workspace. The first relates conscious experience to recurrent thalamo cortical circuits, while the second considers parietotemporal and prefrontal large neural networks as the basis for conscious access. It has been suggested that human consciousness depends on a default network. Furthermore, human consciousness could represent a narrative stream of reflective thought that is critical for the control of actions and is encultured by social interaction.

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