The Experts below are selected from a list of 306 Experts worldwide ranked by ideXlab platform
Xavier Caseras - One of the best experts on this subject based on the ideXlab platform.
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dynamics of brain responses to phobic related stimulation in specific phobia subtypes
European Journal of Neuroscience, 2010Co-Authors: Xavier Caseras, David Mataixcols, Maria Victoria Trasovares, Marina Lopezsola, Hector Ortriz, Jesus Pujol, Carles Sorianomas, Vincent GiampietroAbstract:Very few studies have investigated to what extent different subtypes of specific phobia share the same underlying functional neuroanatomy. This study aims to investigate the potential differences in the anatomy and dynamics of the blood oxygen level-dependent (BOLD) responses associated with spider and blood-injection-injury phobias. We used an event-related paradigm in 14 untreated spider phobics, 15 untreated blood-injection-injury phobics and 17 controls. Phobic images successfully induced distress only in phobic participants. Both phobic groups showed a similar pattern of heart rate increase following the presentation of phobic stimuli, this being different from controls. The presentation of phobic images induced activity within the same brain network in all participants, although the intensity of brain responses was significantly higher in phobics. Only blood-injection-injury phobics showed greater activity in the ventral prefrontal cortex compared with controls. This phobia group also presented a lower activity peak in the left amygdala compared with spider phobics. Importantly, looking at the dynamics of BOLD responses, both phobia groups showed a quicker time-to-peak in the right amygdala than controls, but only spider phobics also differed from controls in this parameter within the left amygdala. Considering these and previous findings, both phobia subtypes show very similar responses regarding their immediate reaction to phobia-related images, but critical differences in their sustained responses to these stimuli. These results highlight the importance of considering complex mental processes potentially associated with coping and emotion regulation processes, rather than exclusively focusing on primary neural responses to threat, when investigating fear and phobias.
Koichi Hirata - One of the best experts on this subject based on the ideXlab platform.
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Topographic Analysis of Electroencephalographic Changes during Photic Driving Responses in Patients with Migraine.
Neuropsychobiology, 2015Co-Authors: Ryotaro Takashima, Hideaki Tanaka, Kazuhito Kimoto, Yuka Watanabe, Koichi HirataAbstract:Objective: Migraineurs demonstrate abnormal information processing such as photic hypersensitivity. The photic driving response to photic stimulation (PS) is a reaction to the visual stimulation of electroencephalography (EEG). Both the photic driving response and photic hypersensitivity appear during light stimulation. We considered that evaluation of a migraineur's photic driving response may help to elucidate the mechanism of the migraineur's sensitive condition. Our study aimed to investigate EEG photic driving responses with a source-localizing method. Methods: We recorded spontaneous resting EEG with eyes closed from 20 electrodes on the scalp during the interictal phase. After recording, each PS was separately selected. We also analyzed EEG by fast Fourier transform and observed the spectrum frequency peaks and topographies in response to PS. Results: The photic driving response could be observed at a flashing rate of >15 Hz. Patients with photic hypersensitivity tended to show more photic driving regardless of the migraine subtype. Moreover, in topographies, their activated areas were shifted anteriorly from fundamental driving to harmonic driving for each photic frequency. This anterior shift was more evident with a longer duration of illness, although no significant differences were seen between migraine subtypes. The global field power value had a positive correlation with the duration of illness. Conclusion: Photic hypersensitivity and photic driving responses were increased in migraineurs. Photic hypersensitivity might result in sensitization of the limbic system.
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The photic driving response in electroencephalogram in migraine patients
2012 ICME International Conference on Complex Medical Engineering (CME), 2012Co-Authors: Ryotaro Takashima, Hideaki Tanaka, Kazuhito Kimoto, Yuka Watanabe, Koichi HirataAbstract:It is well known that the migraine patients indicate abnormal information processing such as photic supersensitivity. And it is high incidence and an aggravation factor of migraine attack. In addition, it is included in the diagnostic criteria of ICHD-?. However, the underlining mechanism is still open for discussion. Our study aimed to investigate the photic driving responses of the electroencephalogram (EEG) with source localizing method. We recorded spontaneous eyes-closed resting EEG from 20 electrodes on the scalp during their inter-ictal phase. Stroboscope flashes consisting of 3–5–8–10–13–15–18–20 Hz were used. After recording, each photic stimulation was selected respectively. And we examined the relation between clinical backgrounds and the prophylaxis. In addition, we analyzed EEG by FFT and observed the frequency peaks and its topographies responded for photic stimulation. The photic driving response could be observed in higher flashing rate than 15 Hz in addition to lower flashing rate. And the case as having photic supersensitivity tended to show a lot of photic driving regardless of migraine subtypes. Moreover, in topographies, their activated areas were shifted anterior from fundamental driving to harmonic driving for each photic frequency. This anterior shift was more evident for longer duration of illness, although no significant differences between subgroups. And the global field power (GFP) value had a positive correlation between the duration of the illness. We conclude that high incidences of photic hypersensitivity and photic driving response in migraineurs were confirmed. The underlying mechanism of photic hypersensitivity might result in sensitization of limbic system.
Debra A. Hope - One of the best experts on this subject based on the ideXlab platform.
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Diagnostic subtype, avoidant personality disorder, and efficacy of cognitive—behavioral group therapy for social phobia
Cognitive Therapy and Research, 1995Co-Authors: Debra A. Hope, James D. Herbert, Cameron WhiteAbstract:Increasing recognition of the heterogeneity of social phobia has led to the development of various subtyping classification schemes and controversy over the boundary between social phobia and avoidant personality disorder (APD). This study investigated the utility of one subtyping system by comparing efficacy of cognitive-behavioral group therapy for generalized social phobia (fears in all major situational domains) and nongeneralized social phobia (fears in multiple domains but at least one unaffected domain). Overall, most subjects improved in treatment, with generalized and nongeneralized social phobics making similar gains. However, because generalized social phobics were more impaired prior to treatment, they continued to be more impaired after treatment on some measures. A second hypothesis that social phobics with APD would respond more poorly to treatment than social phobics without APD was not supported. This study adds to the growing evidence that social phobia and APD, as defined by DSM-III-R, may not be conceptually distinct. Clinical and conceptual implications and directions for future research are discussed.
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Diagnostic subtype, avoidant personality disorder, and efficacy of cognitive-behavioral group therapy for social phobia.
Cognitive Therapy and Research, 1995Co-Authors: Debra A. Hope, James D. Herbert, Cameron WhiteAbstract:Increasing recognition of the heterogeneity of social phobia has led to the development of various subtyping classification schemes and controversy over the boundary between social phobia and avoidant personality disorder (APD). This study investigated the utility of one subtyping system by comparing efficacy of cognitive-behavioral group therapy for generalized social phobia (fears in all major situational domains) and nongeneralized social phobia (fears in multiple domains but at least one unaffected domain). Overall, most subjects improved in treatment, with generalized and nongeneralized social phobics making similar gains. However, because generalized social phobics were more impaired prior to treatment, they continued to be more impaired after treatment on some measures. A second hypothesis that social phobics with APD would respond more poorly to treatment than social phobics without APD was not supported. This study adds to the growing evidence that social phobia and APD, as defined by DSM-III-R, may not be conceptually distinct. Clinical and conceptual implications and directions for future research are discussed.
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Avoidant personality disorder and the generalized subtype of social phobia.
Journal of abnormal psychology, 1992Co-Authors: Craig S. Holt, Richard G. Heimberg, Debra A. HopeAbstract:Social phobia and avoidant personality disorder (APD) may be given as comorbid diagnoses. However, it is not known if the labels provide independent, useful diagnostic information. We classified social phobics by social phobia subtype and presence of APD. Generalized social phobics with and without APD (ns = 10 and 10) and nongeneralized social phobics without APD (n = 10) were distinguished on measures of phobic severity. The generalized groups also showed earlier age at onset and higher scores on measures of depression, fear of negative evaluation, and social anxiety and avoidance than did the nongeneralized group. APD criteria of general timidity and risk aversion were more frequently endorsed by social phobics with APD. The data suggest that both the generalized subtype of social phobia and the presence of APD do provide useful diagnostic information but the additional diagnosis of APD may simply identify a severe subgroup of social phobics.
Vincent Giampietro - One of the best experts on this subject based on the ideXlab platform.
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dynamics of brain responses to phobic related stimulation in specific phobia subtypes
European Journal of Neuroscience, 2010Co-Authors: Xavier Caseras, David Mataixcols, Maria Victoria Trasovares, Marina Lopezsola, Hector Ortriz, Jesus Pujol, Carles Sorianomas, Vincent GiampietroAbstract:Very few studies have investigated to what extent different subtypes of specific phobia share the same underlying functional neuroanatomy. This study aims to investigate the potential differences in the anatomy and dynamics of the blood oxygen level-dependent (BOLD) responses associated with spider and blood-injection-injury phobias. We used an event-related paradigm in 14 untreated spider phobics, 15 untreated blood-injection-injury phobics and 17 controls. Phobic images successfully induced distress only in phobic participants. Both phobic groups showed a similar pattern of heart rate increase following the presentation of phobic stimuli, this being different from controls. The presentation of phobic images induced activity within the same brain network in all participants, although the intensity of brain responses was significantly higher in phobics. Only blood-injection-injury phobics showed greater activity in the ventral prefrontal cortex compared with controls. This phobia group also presented a lower activity peak in the left amygdala compared with spider phobics. Importantly, looking at the dynamics of BOLD responses, both phobia groups showed a quicker time-to-peak in the right amygdala than controls, but only spider phobics also differed from controls in this parameter within the left amygdala. Considering these and previous findings, both phobia subtypes show very similar responses regarding their immediate reaction to phobia-related images, but critical differences in their sustained responses to these stimuli. These results highlight the importance of considering complex mental processes potentially associated with coping and emotion regulation processes, rather than exclusively focusing on primary neural responses to threat, when investigating fear and phobias.
Walton T. Roth - One of the best experts on this subject based on the ideXlab platform.
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taking the laboratory to the skies ambulatory assessment of self report autonomic and respiratory responses in flying phobia
Psychophysiology, 1998Co-Authors: Frank H. Wilhelm, Walton T. RothAbstract:We evaluated the feasibility of recording multiple physiological anxiety measures during a flight and how well they could distinguish flight phobics from controls. Benefits of baseline adjustment and transformation for all variables and adjustment of heart rate by ventilation to give additional heart rate were calculated. Effect size, one measure of the power to discriminate groups, was between 1.1 and 1.7 for heart rate measures. Although respiratory rate and minute ventilation, indicators of hyperventilation, did not differ between groups, phobics paused more during inspiration than did controls. Phobics also showed more skin conductance fluctuations and less respiratory sinus arrhythmia. Self-reported anxiety was a more powerful discriminator than physiological measures, a result that may be partially explained by how phobics were selected. These results indicate that monitoring of multiple physiological systems outside the laboratory is practical and informative. Physiological measures of psychological importance can be quantified accurately in a noisy, changing, unsupervised ambulatory setting.
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Speech disturbances and gaze behavior during public speaking in subtypes of social phobia.
Journal of Anxiety Disorders, 1997Co-Authors: Stefan G. Hofmann, Alexander L. Gerlach, Amy Wender, Walton T. RothAbstract:Twenty-four social phobics with public speaking anxiety and 25 nonphobic individuals (controls) gave a speech in front of two people. Subjective anxiety, gaze behavior, and speech disturbances were assessed. Based on subjects' fear ratings of social situations, phobics and controls were divided into the generalized and nongeneralized subtype. Results showed that generalized phobics reported the most, and nongeneralized controls the least anxiety during public speaking. All subjects had longer and more frequent eye contact when delivering a speech than when talking with an experimenter or sitting in front of an audience. Phobics showed more filled pauses, had longer silent pauses, paused more frequently, and spent more time pausing than controls when giving a speech. Generalized phobics spent more time pausing during their speech than the other subgroups (nongeneralized controls, generalized controls, and nongeneralized phobics). These results suggest that generalized phobics tended to shift attentional resources from speech production to other cognitive tasks.