International journal of psychophysiology : official journal of the International Organization of Psychophysiology
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A number of brain regions are associated with the subjective experience of pain. This study adds to our understanding of the neural mechanisms involved in pain by considering the relation between cortical oscillations in response to pain, with and without hypnosis and hypnotic analgesia, and the subjective experience of pain. Thirty-three subjects' neural responses (EEG) were measured during the 40-540 ms period following phasic electrical stimulations to the right hand, under control and hypnosis conditions. ⋯ This relation was unchanged by hypnosis in the low hypnotisable subjects but was not present in the highs during hypnosis, suggesting that hypnosis interferes with this pain/gamma relation. This study provides evidence for the role of gamma oscillations in the subjective experience of pain. Further, it is in keeping with the view that hypnosis involves the dissociation of prefrontal cortex from other neural functions.
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Int J Psychophysiol · Oct 2002
Clinical TrialEffect of negative air ions on computer operation, anxiety and salivary chromogranin A-like immunoreactivity.
The effects of negative air ions on computer operation were examined using a biochemical index of the activity of the sympathetic/adrenomedullary system (i.e. salivary chromogranin A-like immunoreactivity (CgA-like IR)) and a self-report questionnaire (State-Trait Anxiety Inventory, Anxiety State--STAI-S). Twelve female students carried out a word processing task for 40 min. The salivary CgA-like IR increased more than three times on the task, but the salivary cortisol did not change. ⋯ These effects by negative air ions were also observed using STAI-S. Task performance was slightly but significantly improved by the presence of negative air ions. These results suggest that negative air ions are effective for the reduction of and the prompt recovery from stress caused by computer operation.
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Int J Psychophysiol · Oct 2002
Clinical TrialVariability of EEG synchronization during a working memory task in healthy subjects.
Working memory is associated with an increase in EEG theta synchronization and a decrease in lower alpha band synchronization. We investigated whether such changes in mean synchronization level are accompanied by changes in small scale fluctuations of synchronization. EEGs (19 channels; average reference; sample frequency 250 Hz) were recorded in 21 healthy subjects (12 males; mean age 62.5 years; S. ⋯ Working memory was associated with increased variability in the 2-6 Hz band, and decreased variability in the 6-10 Hz band and, to a lesser extent, in the 14-18 and 18-22 Hz bands. Working memory is accompanied not only by characteristic changes in the mean level of interactions between neural networks, but also by changes in small scale fluctuations in such interactions. Strong, but rapidly fluctuating coupling between neural systems might provide a mechanism to optimize the balance between local differentiation and global integration of brain activity.
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Int J Psychophysiol · Nov 2001
Comparative StudyGender differences in cardiovascular and electrodermal responses to public speaking task: the role of anxiety and mood states.
Gender moderates psychophysiological responses to stress. In addition to the hormonal background, different psychological states related to social stressors, such as anxiety and mood, could affect this response. The purpose of this study was to examine the existence of gender differences in the cardiovascular and electrodermal responses to a speech task and their relationship with anxiety and the mood variations experienced. ⋯ No gender differences for HR and for the frequency of NSRs were found. Anxiety and mood states were differently related to cardiovascular and electrodermal measurements in men and women. Further studies should consider the hormonal variations in addition to the psychological dimensions, in order to offer a more integrative perspective of the complex responses to stress.