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Highlights: [•] Reaction times and P3b latencies of predicted targets were prolonged in depression. [•] P3b amplitudes were attenuated in major depressive disorder during processing of predictive contextual information, as well as target N1 amplitudes. [•] Processing of local contextual processing is altered in major depressive disorder. [ABSTRACT FROM AUTHOR]

Deficits in processing contextual information are one of the main features of cognitive dysfunction in schizophrenia, but the neurophysiologic substrate underlying this dysfunction is poorly understood. We used ERPs to investigate local contextual processing in schizophrenic patients. Local context was defined as the occurrence of a short predictive series of stimuli occurring before delivery of a target event. Response times of predicted targets were faster in controls compared to patients. Schizophrenia patients failed to generate the P3b latency shift between predicted and random targets that was observed in controls and demonstrated a prominent reduction of the peak of an early latency context dependent positivity. The current study provides evidence of contextual processing deficits in schizophrenia patients by demonstrating alteration in the behavioral and neural correlates of local contextual processing. [ABSTRACT FROM AUTHOR]

The rubber-hand illusion (RHI), an illusion in which tactile sensations are referred to a synthetic alien limb, is enhanced in schizophrenia patients. Somatosensory evoked responses of the illusion were compared between schizophrenia patients and normal control subjects. Schizophrenia patients had significant alterations in long latency evoked responses during the illusion. These findings support the hypothesis of alterations in associative higher-level neuronal activity in schizophrenia. The findings support previous results pointing to alterations in associative brain regions in schizophrenia. [Copyright &y& Elsevier]

Highlights: [•] Evaluation of functional connectivity using EEG and graph theory. [•] Schizophrenia and PD patients perform contextual processing task. [•] Stimulus-specific decrease of path length in schizophrenia patients. [•] Context-dependent increase of path length and clustering coefficient in PD patients. [•] Abnormalities associated with weaker connections within frontal networks. [Copyright &y& Elsevier]