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Individual Sensitivity (individual + sensitivity)
Selected AbstractsA Single Gene May Account For Individual SensitivitiesAUSTRALIAN ENDODONTIC JOURNAL, Issue 2 2000Article first published online: 11 FEB 2010 No abstract is available for this article. [source] Individual sensitivity to pain expectancy is related to differential activation of the hippocampus and amygdalaHUMAN BRAIN MAPPING, Issue 2 2010Michal Ziv Abstract Anxiety arising during pain expectancy can modulate the subjective experience of pain. However, individuals differ in their sensitivity to pain expectancy. The amygdale and hippocampus were proposed to mediate the behavioral response to aversive stimuli. However, their differential role in mediating anxiety-related individual differences is not clear. Using fMRI, we investigated brain activity during expectancy to cued or uncued thermal pain applied to the wrist. Following each stimulation participants rated the intensity of the painful experience. Activations in the amygdala and hippocampus were examined with respect to individual differences in harm avoidance (HA) personality trait, and individual sensitivity to expectancy, (i.e. response to cued vs. uncued painful stimuli). Only half of the subjects reported on cued pain as being more painful than uncued pain. In addition, we found a different activation profile for the amygdala and hippocampus during pain expectancy and experience. The amygdala was more active during expectancy and this activity was correlated with HA scores. The hippocampal activity was equally increased during both pain expectancy and experience, and correlated with the individual's sensitivity to expectancy. Our findings suggest that the amygdala supports an innate tendency to approach or avoid pain as reflected in HA trait, whereas the hippocampus mediates the effect of context possibly via appraisal of the stimulus value. Hum Brain Mapp, 2010. © 2009 Wiley-Liss, Inc. [source] Effect of low frequency modulated microwave exposure on human EEG: Individual sensitivityBIOELECTROMAGNETICS, Issue 7 2008Hiie Hinrikus Abstract The aim of this study was to evaluate the effect of modulated microwave exposure on human EEG of individual subjects. The experiments were carried out on four different groups of healthy volunteers. The 450 MHz microwave radiation modulated at 7 Hz (first group, 19 subjects), 14 and 21 Hz (second group, 13 subjects), 40 and 70 Hz (third group, 15 subjects), 217 and 1000 Hz (fourth group, 19 subjects) frequencies was applied. The field power density at the scalp was 0.16 mW/cm2. The calculated spatial peak SAR averaged over 1 g was 0.303 W/kg. Ten cycles of the exposure (1 min off and 1 min on) at fixed modulation frequencies were applied. All subjects completed the experimental protocols with exposure and sham. The exposed and sham-exposed subjects were randomly assigned. A computer also randomly assigned the succession of modulation frequencies. Our results showed that microwave exposure increased the EEG energy. Relative changes in the EEG beta1 power in P3-P4 channels were selected for evaluation of individual sensitivity. The rate of subjects significantly affected is similar in all groups except for the 1000 Hz group: in first group 3 subjects (16%) at 7 Hz modulation; in second group 4 subjects (31%) at 14 Hz modulation and 3 subjects (23%) at 21 Hz modulation; in third group 3 subjects (20%) at 40 Hz and 2 subjects (13%) at 70 Hz modulation; in fourth group 3 subjects (16%) at 217 Hz and 0 subjects at 1000 Hz modulation frequency. Bioelectromagnetics 29:527,538, 2008. © 2008 Wiley-Liss, Inc. [source] Individual sensitivity to pain expectancy is related to differential activation of the hippocampus and amygdalaHUMAN BRAIN MAPPING, Issue 2 2010Michal Ziv Abstract Anxiety arising during pain expectancy can modulate the subjective experience of pain. However, individuals differ in their sensitivity to pain expectancy. The amygdale and hippocampus were proposed to mediate the behavioral response to aversive stimuli. However, their differential role in mediating anxiety-related individual differences is not clear. Using fMRI, we investigated brain activity during expectancy to cued or uncued thermal pain applied to the wrist. Following each stimulation participants rated the intensity of the painful experience. Activations in the amygdala and hippocampus were examined with respect to individual differences in harm avoidance (HA) personality trait, and individual sensitivity to expectancy, (i.e. response to cued vs. uncued painful stimuli). Only half of the subjects reported on cued pain as being more painful than uncued pain. In addition, we found a different activation profile for the amygdala and hippocampus during pain expectancy and experience. The amygdala was more active during expectancy and this activity was correlated with HA scores. The hippocampal activity was equally increased during both pain expectancy and experience, and correlated with the individual's sensitivity to expectancy. Our findings suggest that the amygdala supports an innate tendency to approach or avoid pain as reflected in HA trait, whereas the hippocampus mediates the effect of context possibly via appraisal of the stimulus value. Hum Brain Mapp, 2010. © 2009 Wiley-Liss, Inc. [source] Pressure,pain threshold determination in the oral mucosa: validity and reliabilityJOURNAL OF ORAL REHABILITATION, Issue 7 2002T. Ogimoto Fundamental knowledge of pain in the oral mucosa is lacking. We determined the validity and reliability of the pressure,pain threshold (PPT) measurement in the oral mucosa using a newly developed hand-held pressure algometer. Ten dentulous subjects were recruited, and the PPT was measured at the bilateral buccal (on the attached gingiva apical to the midline of the upper first premolars, 3 mm from the mucogingival junction) and the palatal sites (mid-point between the bilateral upper first molars). The PPT linearly increased with an increase in load-rate (P < 0·0001). The PPT yielded a high intra-individual stability both for the same-day consecutive trials and weekly sessions. The palatal site revealed a 4- to 4·65-fold greater PPT than the buccal sites (Bonferroni, P < 0·0001), whereas no difference was found between the bilateral buccal sites (P=0·663). Despite a great interindividual variation in the PPT, significant intra-individual correlations were found among the measurement sites. This suggested differences in individual sensitivity to pain in the oral mucosa, which may determine overall pain sensation specific to an individual. A pressure algometer described herein reliably assessed the PPT in the oral mucosa and sensitively discriminated PPT differences at different sites and at different load-rates, suggest-ing the reliability and validity of PPT measure-ments in the oral mucosa for clinical and research investigations. [source] Effect of low frequency modulated microwave exposure on human EEG: Individual sensitivityBIOELECTROMAGNETICS, Issue 7 2008Hiie Hinrikus Abstract The aim of this study was to evaluate the effect of modulated microwave exposure on human EEG of individual subjects. The experiments were carried out on four different groups of healthy volunteers. The 450 MHz microwave radiation modulated at 7 Hz (first group, 19 subjects), 14 and 21 Hz (second group, 13 subjects), 40 and 70 Hz (third group, 15 subjects), 217 and 1000 Hz (fourth group, 19 subjects) frequencies was applied. The field power density at the scalp was 0.16 mW/cm2. The calculated spatial peak SAR averaged over 1 g was 0.303 W/kg. Ten cycles of the exposure (1 min off and 1 min on) at fixed modulation frequencies were applied. All subjects completed the experimental protocols with exposure and sham. The exposed and sham-exposed subjects were randomly assigned. A computer also randomly assigned the succession of modulation frequencies. Our results showed that microwave exposure increased the EEG energy. Relative changes in the EEG beta1 power in P3-P4 channels were selected for evaluation of individual sensitivity. The rate of subjects significantly affected is similar in all groups except for the 1000 Hz group: in first group 3 subjects (16%) at 7 Hz modulation; in second group 4 subjects (31%) at 14 Hz modulation and 3 subjects (23%) at 21 Hz modulation; in third group 3 subjects (20%) at 40 Hz and 2 subjects (13%) at 70 Hz modulation; in fourth group 3 subjects (16%) at 217 Hz and 0 subjects at 1000 Hz modulation frequency. Bioelectromagnetics 29:527,538, 2008. © 2008 Wiley-Liss, Inc. [source] Individual sensitivity to pain expectancy is related to differential activation of the hippocampus and amygdalaHUMAN BRAIN MAPPING, Issue 2 2010Michal Ziv Abstract Anxiety arising during pain expectancy can modulate the subjective experience of pain. However, individuals differ in their sensitivity to pain expectancy. The amygdale and hippocampus were proposed to mediate the behavioral response to aversive stimuli. However, their differential role in mediating anxiety-related individual differences is not clear. Using fMRI, we investigated brain activity during expectancy to cued or uncued thermal pain applied to the wrist. Following each stimulation participants rated the intensity of the painful experience. Activations in the amygdala and hippocampus were examined with respect to individual differences in harm avoidance (HA) personality trait, and individual sensitivity to expectancy, (i.e. response to cued vs. uncued painful stimuli). Only half of the subjects reported on cued pain as being more painful than uncued pain. In addition, we found a different activation profile for the amygdala and hippocampus during pain expectancy and experience. The amygdala was more active during expectancy and this activity was correlated with HA scores. The hippocampal activity was equally increased during both pain expectancy and experience, and correlated with the individual's sensitivity to expectancy. Our findings suggest that the amygdala supports an innate tendency to approach or avoid pain as reflected in HA trait, whereas the hippocampus mediates the effect of context possibly via appraisal of the stimulus value. Hum Brain Mapp, 2010. © 2009 Wiley-Liss, Inc. [source] Pseudoparadoxical impulsivity in restrictive anorexia nervosa: A consequence of the logic of scarcityINTERNATIONAL JOURNAL OF EATING DISORDERS, Issue 4 2002Daniel M. T. Fessler Abstract Objective To explain an apparently paradoxical pattern wherein sufferers of restrictive anorexia nervosa exhibit both rigorous self-restraint and episodic impulsivity. Method The experimental, historical, and clinical literatures were examined for evidence of psychological and behavioral changes accompanying severe dietary constriction; such changes were noted and compared with those reported to occur in anorexics. Results Increased impulsivity in association with dietary constriction is described in diverse literatures. A number of lines of evidence suggest that the serotonergic system mediates this change. Discussion Many forms of impulsivity can be understood as having once constituted fitness-enhancing responses to resource scarcity. It is suggested that an evolved psychological mechanism calibrates the individual's sensitivity to risk in light of future prospects. Self-injurious behaviors are explicable as misfirings of such a mechanism. Similarly, excessive exercising by anorexics may reflect the misdirection of reward systems that normally encourage adaptive increases in ranging behavior under conditions of scarcity. © 2002 by Wiley Periodicals, Inc. Int J Eat Disord 31: 376,388, 2002. [source] Quantitative Trait Loci Affecting Ethanol Sensitivity in BXD Recombinant Inbred MiceALCOHOLISM, Issue 1 2000Kaitlin E. Browman Background: Genetic and environmental factors contribute to an individual's sensitivity to ethanol, although the exact genes underlying ethanol's effects are not known. Quantitative trait locus (QTL) mapping is one successful method for provisionally identifying genes participating in the mediation of a given behavior. QTL analyses seek to identify associations between a quantitative response and previously mapped marker genes across genetically diverse individuals. Many QTL analyses have been performed in BXD recombinant inbred (RI) strains of mice derived from a cross of C57BL/6J (B6) and DBA/2J (D2) progenitor strains. Methods: We conducted a QTL analysis of ethanol-induced loss of righting reflex and ataxia using a panel of 25 BXD RI strains and the progenitors B6 and D2. We measured the duration of loss of righting reflex after injection and blood ethanol concentrations upon regaining of righting reflex. Ataxia was measured as the latency to fall from a vertical screen. Results: Genome-wide QTL analyses correlating strain means with allelic status at >1500 markers identified several associations (p, 0.01). These provisional QTLs were on all chromosomes except 2,5,12,13, and X, and several map near potential candidate genes. Conclusions: These results suggest that ethanol sensitivity is determined by the actions of multiple genes and further suggest their general chromosomal map locations. These provisional linkages will now be confirmed or rejected using additional genetically segregating populations. [source] |