Gamma band oscillations participate in the temporal binding needed to synchronize cortical networks, involved in early sensory and short term memory processes. In earlier studies, alterations of these neurophysiological parameters have been found in psychotic disorders. To date no study has explored the temporal dynamics and signal complexity of gamma band oscillations in first episode psychosis (FEP). To address this issue, gamma band analysis was performed in 15 FEP patients and 18 healthy controls who successfully performed an adapted 2-back working memory task. Multiple linear and logistic regression models were computed to explore the relationship between the cognitive status and gamma oscillation changes over time. Based on regression model results, phase diagrams were constructed and their complexity was estimated using fractal dimension, a mathematical tool that describes shapes as numeric values. When adjusted for gamma values at time lags-3 to-4 ms and-15 to-16 ms, FEP patients displayed significantly higher time-dependent changes than controls, independently of the nature of the task. The present results are consistent with a discoordination of the activity of cortical generators engaged by the stimulus apparition in FEP patients, leading to a global binding deficit. In addition, fractal analysis showing higher complexity of gamma signal, confirmed this deficit. Our results provide evidence for recruitment of supplementary cortical generators as compensating mechanisms and yield further understanding for the pathophysiology cognitive impairments in FEP.

These results are consistent with the hypotheses that working memory dysfunction in patients with schizophrenia is caused by a disturbance of the dorsolateral prefrontal cortex and that this disturbance is selectively associated with cognitive disorganization. Further, the pattern of behavioral performance suggests that dorsolateral prefrontal cortex dysfunction does not reflect a deficit in the maintenance of stimulus representations per se but points to deficits in more associative components of working memory.

This study evaluates transfer from domain-specific, sensorimotor training to cognitive abilities associated with executive function. We examined Individualized Piano Instruction (IPI) as a potential cognitive intervention to mitigate normal age-related cognitive decline in older adults. Thirty-one musically naïve community-dwelling older adults (ages 60-85) were randomly assigned to either the experimental group (n = 16) or control group (n = 15). Neuropsychological assessments were administered at three time points: pre-training, following six months of intervention, and following a three-month delay. The experimental group significantly improved performance on the Trail Making Test and Digit Symbol measures as compared to healthy controls. Results of this study suggest that IPI may serve as an effective cognitive intervention for age-related cognitive decline.

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Previous experiments found that placebos produced small decreases in neural activity of pain-related areas of the brain, yet decreases were only statistically significant after termination of stimuli and in proximity to when subjects rated them. These changes could reflect report bias rather than analgesia. This functional magnetic resonance imaging (fMRI) study examined whether placebo analgesia is accompanied by reductions in neural activity in pain-related areas of the brain during the time of stimulation. Brain activity of irritable bowel syndrome patients was measured in response to rectal distension by a balloon barostat. Large reductions in pain and in brain activation within pain-related regions (thalamus, somatosensory cortices, insula, and anterior cingulate cortex) occurred during the placebo condition. Results indicate that decreases in activity were related to placebo suggestion and a second factor (habituation/attention/conditioning). Although many factors influence placebo analgesia, it is accompanied by reduction in pain processing within the brain in clinically relevant conditions.

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These results confirm the importance of using tasks that tap specific cognitive functions, linked to specific neural systems, in studies of brain-behavior relationships in schizophrenia. Hypofrontality is reliably demonstrated in schizophrenia during tasks that engage working memory functions of the prefrontal cortex.

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