Journal of neural transmission
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We measured brain activities with a whole head magnetoencephalograph (MEG) to investigate the influence of a background odor on alphabetical encoding of words in 20 healthy volunteers (10 females). Odor stimulation and control air stimulation were both accomplished with a computer-controlled olfactometer by providing permanent stimulation conditions. Behavioral data revealed significantly prolonged reaction times in men under the influence of phenylethyl alcohol (PEA) compared to the control condition. ⋯ Analysis of grand averaged, event-related fields and localization of the underlying equivalent current dipoles revealed higher dipole strength in the odor, compared to the control condition in the right hemisphere, over the temporo-parietal brain areas, in the time range between 200 and 500 ms after word-onset only in male subjects. Within this time range, the gender-specific effect is interpreted to reflect odor-related modulation of word processing. The findings suggest gender-specific processing strategies in the present task with implications for differences in hemispheric laterality.
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Differential associations between brain 5-HT(1A) receptor binding and response to pain versus touch.
We studied whether brain serotonin 5-HT(1A) receptor availability is associated with response to noxious heat versus tactile stimuli, and short-term memory for heat pain. Psychophysical performance was assessed in 16 healthy subjects who had participated in a positron emission tomography study using [carbonyl-11C]WAY-100635 ligand for the assessment of 5-HT(1A) receptor binding potential (BP (ND)). ⋯ Subject's response criterion for heat pain was inversely correlated with 5-HT(1A) BP (ND) in the dorsal raphe, middle temporal gyrus, orbitofrontal cortex and posterior cingulum, whereas the subject's discriminative capacity for touch was inversely correlated with 5-HT(1A) BP (ND) in the cingulum, inferior temporal gyrus, and medial prefrontal cortex. Certainty ratings of the responses, but not hit rates, in the pain memory task were correlated with 5-HT(1A) BP (ND) in the dorsal raphe.
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There is a general belief that physical activity and exercise have positive effects on mood and anxiety and a great number of studies describe an association of physical activity and general well-being, mood and anxiety. In line, intervention studies describe an anxiolytic and antidepressive activity of exercise in healthy subjects and patients. However, the majority of published studies have substantial methodological shortcomings. ⋯ Although, the evidence for positive effects of exercise and exercise training on depression and anxiety is growing, the clinical use, at least as an adjunct to established treatment approaches like psychotherapy or pharmacotherapy, is still at the beginning. Further studies on the clinical effects of exercise, interaction with standard treatment approaches and details on the optimal type, intensity, frequency and duration may further support the clinical administration in patients. Furthermore, there is a lack of knowledge on how to best deal with depression and anxiety related symptoms which hinder patients to participate and benefit from exercise training.
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The hypervigilance-avoidance hypothesis assumes that anxious individuals initially attend to and subsequently avoid threatening stimuli. In this study pairs of emotional (angry or happy) and neutral facial expressions were presented to students of high or low fear of negative evaluation (FNE) while their eye movements were recorded. High FNE participants initially looked more often at emotional compared to neutral faces, indicating an attentional bias for emotional facial expressions. ⋯ Analysis of the time course of attention revealed that high FNE looked at the emotional faces longer during the first second of stimulus exposure, whereas they avoided these faces in the consecutive time interval from 1 to 1.5 s. These results partially support the hypervigilance-avoidance hypothesis and additionally indicate the relevance of happy faces for high FNE. Further research should clarify the meaning of happy facial expressions as well as the influence of the sex of the observed face in social anxiety.
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The aetiology of dystonia in complex regional pain syndrome (CRPS-I) is incompletely understood. In primary dystonia, somatosensory-evoked potentials (SSEP) after spatially or temporally separated stimulation revealed impaired central sensory integration. Information on somatosensory processing in dystonia in CRPS-I patients may provide better insight into the underlying pathophysiological mechanism. ⋯ Spatiotemporal stimulation did not show an additional suppressive effect in any group. Central sensory integration of proprioceptive afferent input is normal in patients with CPRS-related dystonia. Other mechanisms may underlie the development of dystonia in this disorder.