International journal of psychophysiology : official journal of the International Organization of Psychophysiology
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Int J Psychophysiol · Nov 2013
Brain oscillation and connectivity during a chemistry visual working memory task.
Many studies have reported that frontal theta and posterior alpha activities are associated with working memory tasks. However, fewer studies have focused on examining whether or not the frontal alpha or posterior theta can play a role in the working memory task. This study investigates electroencephalography (EEG) dynamics and connectivity among different brain regions' theta and alpha oscillations. ⋯ Study of the central parietal and the occipital clusters revealed a sequence of theta augmentation followed by alpha suppression at constant intervals after the onset of stimulus and probe presentations, suggesting that the posterior theta might be associated with sensory processing, theta gating, or stimulus selection. It further suggests that the posterior alpha event-related de-synchronization (ERD) might be linked to direct information flow into and out of the long-term memory (LTM) and precede stimulus recognition. An alternating phasic alpha event-related synchronization (ERS) and ERD following the 1st stimulus and probe presentations were observed at the occipital cluster, in which alpha ERS might be linked to the inhibition of irrelevant information.
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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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Int J Psychophysiol · Nov 2013
Mindfulness (Vipassana) meditation: effects on P3b event-related potential and heart rate variability.
The concept of mindfulness is based on Vipassana, a Buddhist meditation technique. The present study examines the physiological indices of attention and autonomic regulation in experienced Vipassana meditators to test the claim that mindfulness is an effective therapeutic tool due to its effects on increasing awareness of present experience and emotional self-regulation. Ten male experienced Vipassana meditators underwent two assessment sessions, one where they practiced Vipassana meditation and another where they rested with no meditation (random thinking). ⋯ The Vipassana experts showed greater P3b amplitudes to the target tone after meditation than they did both before meditation and after the no-meditation session. They also showed a larger LF/HF ratio increase during specific Vipassana meditation. These results suggest that expert Vipassana meditators showed increased attentional engagement after meditation and increased autonomic regulation during meditation supporting, at least partially, the two claims concerning the clinical effectiveness of mindfulness.