International journal of psychophysiology : official journal of the International Organization of Psychophysiology
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Int J Psychophysiol · Nov 2013
Examining emotional modulation of pain and spinal nociception in Native Americans: a preliminary investigation.
Pain problems are more prevalent in Native Americans than in any other group in the U. S., and this might result from group differences in pain modulation. This study was designed to examine emotional modulation of pain and spinal nociception in healthy, pain-free Native Americans (n = 21) relative to non-Hispanic Whites (n = 20). ⋯ Emotional modulation of NFR was similar in both groups. These preliminary findings suggest that Native Americans failed to disinhibit pain, perhaps due to over-activation of pain inhibitory mechanisms. Chronic over-activation of this system could ultimately exhaust it, thus putting Native Americans at future risk for chronic pain.
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Chronic cannabis use has been associated with neurocognitive deficits, alterations in brain structure and function, and with psychosis. This study investigated the effects of chronic cannabis use on P50 sensory-gating in regular users, and explored the association between sensory gating, cannabis use history and the development of psychotic-like symptoms. Twenty controls and 21 regular cannabis users completed a P50 paired-click (S1 and S2) paradigm with an inter-pair interval of 9s. ⋯ These results suggest that prolonged exposure to cannabis results in impaired P50 sensory-gating in long-term cannabis users. While it is possible that these deficits may have pre-dated cannabis use and reflect a vulnerability to cannabis use, their association with increasing years of cannabis use suggests that this is not the case. Impaired P50 sensory-gating ratios have also been reported in patients with schizophrenia and may indicate a similar underlying pathology.
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Int J Psychophysiol · Sep 2013
Mindfulness meditation, well-being, and heart rate variability: a preliminary investigation into the impact of intensive Vipassana meditation.
Mindfulness meditation has beneficial effects on brain and body, yet the impact of Vipassana, a type of mindfulness meditation, on heart rate variability (HRV) - a psychophysiological marker of mental and physical health - is unknown. We hypothesised increases in measures of well-being and HRV, and decreases in ill-being after training in Vipassana compared to before (time effects), during the meditation task compared to resting baseline (task effects), and a time by task interaction with more pronounced differences between tasks after Vipassana training. HRV (5-minute resting baseline vs. 5-minute meditation) was collected from 36 participants before and after they completed a 10-day intensive Vipassana retreat. ⋯ Post-Vipassana, the meditation task increased HF n.u. and decreased THM compared to resting baseline, suggesting post-Vipassana task-related changes are characterised by a decrease in absolute LF power, not parasympathetic-mediated increases in HF power. Such baroreflex changes are classically associated with attentional load, and our results are interpreted in light of the concept of 'flow' - a state of positive and full immersion in an activity. These results are also consistent with changes in normalised HRV reported in other meditation studies.
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Int J Psychophysiol · Sep 2013
Can event-related potentials serve as neural markers for wins, losses, and near-wins in a gambling task? A principal components analysis.
Originally, the feedback related negativity (FRN) event-related potential (ERP) component was considered to be a robust neural correlate of non-reward/punishment processing, with greater negative deflections observed following unfavourable outcomes. More recently, it has been suggested that this component is better conceptualised as a positive deflection following rewarding outcomes. The current study sought to elucidate the nature of the FRN, as well as another component associated with incentive-value processing, the P3b, through application of a spatiotemporal principal components analysis (PCA). ⋯ Interestingly, near-wins elicited significantly smaller FRN amplitudes than losses (with no differences in P3b amplitude), and may contribute to the maintenance of gambling behaviours on EGMs. The results of the current study are integrated into a response profile of healthy controls to outcomes of varying incentive value. This may provide a foundation for the future examination of individuals who exhibit abnormalities in reward/punishment processing, such as problem gamblers.
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Int J Psychophysiol · Aug 2013
ReviewEffects of continuous positive airway pressure on cognitition and neuroimaging data in sleep apnea.
Obstructive sleep apnea (OSA) has been associated with a broad range of neurocognitive difficulties. The current view is that the neurocognitive impairment in OSA is due to the adverse effects of sleep fragmentation and/or intermittent hypoxia. The overall picture of cognitive deficits in OSA is complex. ⋯ Neuroimaging studies performed during cognitive testing have provided insight into CPAP's effect on function of neuroanatomical circuits in the brain. Although neuroimaging can provide important insights into the structural and functional differences associated with OSA, one of the challenges is to interpret the findings in light of comorbid conditions that also cause neural injury. The purpose of this article is to provide a narrative review of the publications on cognition and neuroimaging in OSA before and after CPAP treatment.