More than fear? Brain activation patterns of dental phobic patients before and after an exposure-based treatment.

Hyperactivation of brain networks conferring defensive mobilization is assumed to underlie inappropriate defensive-preparation in patients with Specific Phobia. However, studies targeting Dental Phobia (DP) yielded quite heterogeneous results and research concerning the effects of exposure treatments on phobic brain activation so far is missing. This functional Magnetic Resonance Imaging (fMRI) study aimed to investigate activation patterns in DP patients during exposure to phobia-related stimuli and the effects of an exposure-based fear treatment on phobia-related activation. Seventeen patients with DP and seventeen non-phobic, healthy controls participated in this fMRI experiment presenting dental-related and neutral auditory and visual stimuli. After completing a short exposure-based CBT program, patients were scanned a second time to illustrate treatment-related changes in brain activation patterns. Pre-treatment fMRI results demonstrate enhanced activation in DP-patients mainly in the precuneus and lateral parietal cortex. Moreover, a small activation focus was observed in the amygdala and anterior cingulate cortex (ACC) as parts of classically fear-related structures. Activation in all these clusters decreased significantly from pre- to post-treatment assessment and in the case of the ACC was correlated with dental fear reduction. Activation changes in the precuneus and lateral parietal cortex suggest a pronounced first-person perspective memory processing including a vivid recall of contextual information from an egocentric perspective triggered by exposure to phobia-related stimuli. Besides a treatment-sensitive hyperactivity of fear-sensitive structures, DP may also be characterized by a disturbed memory retrieval that can be reorganized by successful exposure treatment.

Patient preferences for development in MRI scanner design: a survey of claustrophobic patients in a randomized study.

OBJECTIVE: To investigate which magnetic resonance imaging (MRI) scanner designs claustrophobic patients prefer. MATERIAL/METHODS: We analyzed questionnaires completed by 160 patients at high risk for claustrophobia directly after a scan in either a short-bore or open panoramic scanner as part of a prospective randomized trial Enders et al (BMC Med Imaging 11:4, 2011). Scanner preferences were judged based on schematic drawings of four scanners. Information on the diagnostic performance of the depicted scanners was provided, too. RESULTS: A majority of patients suggested upright open (59/160, 36.9%) and open panoramic (53/160, 33.1%) before short-bore designs (26/160, 16.3%, for all p < 0.001) for future development. When asked about patients' preferred scanner choice for an upcoming examination, information about a better diagnostic performance of a short-bore scanner significantly improved its preference rates (from 6/160 to 49/160 or 3.8 to 30.5%, p < 0.001). Patients with a claustrophobic event preferred open designs significantly more often than patients without a claustrophobic event (p = 0.047). Patients scanned in a short-bore scanner in our trial preferred this design significantly more often (p = 0.003). Noise reduction (51/160, 31.9%), more space over the head (44/160, 27.5%), and overall more space (33/160, 20.6%) were the commonest suggested areas of improvement. CONCLUSION: Patients at high risk for claustrophobia visually prefer open- over short-bore MRI designs for further development. Education about a better diagnostic performance of a visually less-attractive scanner can increase its acceptance. Noise and space were of most concern for claustrophobic patients. This information can guide individual referral of claustrophobic patients to scanners and future scanner development. KEY POINTS: • Patients at high risk for claustrophobia visually favor the further development of open scanners as opposed to short- and closed-bore scanner designs. • Educating claustrophobic patients about a higher diagnostic performance of a short-bore scanner can significantly increase their acceptance of this otherwise visually less-attractive design. • A medical history of earlier claustrophobic events in a given MRI scanner type and focusing on the features "more space" and "noise reduction" can help to guide referral of patients who are at high risk for claustrophobia.

Audio-guided self-hypnosis for reduction of claustrophobia during MR imaging: results of an observational 2-group study.

OBJECTIVES: To evaluate the influence of audio-guided self-hypnosis on claustrophobia in a high-risk cohort undergoing magnetic resonance (MR) imaging. METHODS: In this prospective observational 2-group study, 55 patients (69% female, mean age 53.6 ± 13.9) used self-hypnosis directly before imaging. Claustrophobia included premature termination, sedation, and coping actions. The claustrophobia questionnaire (CLQ) was completed before self-hypnosis and after MR imaging. Results were compared to a control cohort of 89 patients examined on the same open MR scanner using logistic regression for multivariate analysis. Furthermore, patients were asked about their preferences for future imaging. RESULTS: There was significantly fewer claustrophobia in the self-hypnosis group (16%; 9/55), compared with the control group (43%; 38/89; odds ratio .14; p = .001). Self-hypnosis patients also needed less sedation (2% vs 16%; 1/55 vs 14/89; odds ratio .1; p = .008) and non-sedation coping actions (13% vs 28%; 7/55 vs 25/89; odds ratio .3; p = .02). Self-hypnosis did not influence the CLQ results measured before and after MR imaging (p = .79). Self-hypnosis reduced the frequency of claustrophobia in the subgroup of patients above an established CLQ cut-off of .33 from 47% (37/78) to 18% (9/49; p = .002). In the subgroup below the CLQ cut-off of 0.33, there were no significant differences (0% vs 9%, 0/6 vs 1/11; p = 1.0). Most patients (67%; 35/52) preferred self-hypnosis for future MR examinations. CONCLUSIONS: Self-hypnosis reduced claustrophobia in high-risk patients undergoing imaging in an open MR scanner and might reduce the need for sedation and non-sedation coping actions. KEY POINTS: • Forty percent of the patients at high risk for claustrophobia may also experience a claustrophobic event in an open MR scanner. • Self-hypnosis while listening to an audio in the waiting room before the examination may reduce claustrophobic events in over 50% of patients with high risk for claustrophobia. • Self-hypnosis may also reduce the need for sedation and other time-consuming non-sedation coping actions and is preferred by high-risk patients for future examinations.

Neural processing of emotional facial stimuli in specific phobia: An fMRI study.

BACKGROUND: Patients with specific phobia (SP) show altered brain activation when confronted with phobia-specific stimuli. It is unclear whether this pathogenic activation pattern generalizes to other emotional stimuli. This study addresses this question by employing a well-powered sample while implementing an established paradigm using nonspecific aversive facial stimuli. METHODS: N = 111 patients with SP, spider subtype, and N = 111 healthy controls (HCs) performed a supraliminal emotional face-matching paradigm contrasting aversive faces versus shapes in a 3-T magnetic resonance imaging scanner. We performed region of interest (ROI) analyses for the amygdala, the insula, and the anterior cingulate cortex using univariate as well as machine-learning-based multivariate statistics based on this data. Additionally, we investigated functional connectivity by means of psychophysiological interaction (PPI). RESULTS: Although the presentation of emotional faces showed significant activation in all three ROIs across both groups, no group differences emerged in all ROIs. Across both groups and in the HC > SP contrast, PPI analyses showed significant task-related connectivity of brain areas typically linked to higher-order emotion processing with the amygdala. The machine learning approach based on whole-brain activity patterns could significantly differentiate the groups with 73% balanced accuracy. CONCLUSIONS: Patients suffering from SP are characterized by differences in the connectivity of the amygdala and areas typically linked to emotional processing in response to aversive facial stimuli (inferior parietal cortex, fusiform gyrus, middle cingulate, postcentral cortex, and insula). This might implicate a subtle difference in the processing of nonspecific emotional stimuli and warrants more research furthering our understanding of neurofunctional alteration in patients with SP.

Reducing Amygdala Activity and Phobic Fear through Cognitive Top-Down Regulation.

The amygdala is critically involved in emotional processing, including fear responses, and shows hyperactivity in anxiety disorders. Previous research in healthy participants has indicated that amygdala activity is down-regulated by cognitively demanding tasks that engage the PFC. It is unknown, however, if such an acute down-regulation of amygdala activity might correlate with reduced fear in anxious participants. In an fMRI study of 43 participants (11 men) with fear of snakes, we found reduced amygdala activity when visual stimuli were processed under high cognitive load, irrespective of whether the stimuli were of neutral or phobic content. Furthermore, dynamic causal modeling revealed that this general reduction in amygdala activity was partially mediated by a load-dependent increase in dorsolateral PFC activity. Importantly, high cognitive load also resulted in an acute decrease in perceived phobic fear while viewing the fearful stimuli. In conclusion, our data indicate that a cognitively demanding task results in a top-down regulation of amygdala activity and an acute reduction of fear in phobic participants. These findings may inspire the development of novel psychological intervention approaches aimed at reducing fear in anxiety disorders.

Biobehavioral threat sensitivity and amygdala volume: A twin neuroimaging study.

Current literature on the relationship between dispositional fear (or threat sensitivity) and amygdala gray matter volume (GMV) is heterogeneous, with findings including positive, negative, and null correlations. A clearer understanding of this relationship would help to determine the potential utility of amygdala volume as a biomarker of anxious/depressive (internalizing) disorders and contribute to understanding of neural mechanisms for variations in fearfulness. The study reported here used voxel-based morphometry to quantify amygdala GMV scores from structural neuroimaging data in a sample of 44 monozygotic twins (i.e., 22 pairs). Dispositional threat sensitivity (THT) was quantified using a biobehavioral cross-domain score that combined neurophysiological indicators with a psychological scale measure. Analyses revealed expected high concordance for amygdala GMV between co-twins. With respect to the major question of the study, a negative correlation was found between biobehavioral THT scores and amygdala volume - with individuals higher in THT showing smaller amygdala GMV scores. More modest associations of amygdala GMV with symptoms of social phobia, and fear disorder symptomology more broadly, were mediated by THT. These results provide insight into prior mixed findings and support the combined use of biological and behavioral measures to quantify characteristics relevant to mental health problems.

ROI and phobias: The effect of ROI approach on an ALE meta-analysis of specific phobias.

About 90% of fMRI findings on specific phobias (SP) include analysis of region of interest (ROI). This approach characterized by higher sensitivity may produce inflated results, particularly when findings are aggregated in meta-analytic maps. Here, we conducted a systematic review and activation likelihood estimation (ALE) meta-analysis on SP, testing the impact of the inclusion of ROI-based studies. ALE meta-analyses were carried out either including ROI-based results or focusing on whole-brain voxelwise studies exclusively. To assess the risk of bias in the neuroimaging field, we modified the Newcastle-Ottawa Scale (NOS) and measured the reliability of fMRI findings. Of the 31 selected investigations (564 patients and 485 controls) one-third did not motivate ROI selection: five studies did not report an explicit rationale, whereas four did not cite any specific reference in this regard. Analyses including ROI-based studies revealed differences between phobics and healthy subjects in several regions of the limbic circuit. However, when focusing on whole-brain analysis, only the anterior midcingulate cortex differentiated SP from controls. Notably, 13 studies were labeled with low risk of bias according to the adapted NOS. The inclusion of ROI-based results artificially inflates group differences in fMRI meta-analyses. Moreover, a priori, well-motivated selection of ROIs is desirable to improve quality and reproducibility in SP neuroimaging studies. Lastly, the use of modified NOS may represent a valuable way to assess and evaluate biases in fMRI studies: "low risk" of bias was reported for less than half of the included studies, indicating the need for better practices in fMRI.

Glucocorticoid administration restores salience network activity in patients with spider phobia.

BACKGROUND: Glucocorticoids reduce phobic fear in patients with anxiety disorders. Although the neurobiology of anxiety disorders is not fully understood, convergent structural and functional neuroimaging studies have identified abnormalities in various brain regions, including those in the salience network (SN) and default mode network (DMN). Here, we examine the effects of glucocorticoid administration on SN and DMN activity during the processing of phobic stimuli. METHODS: We use functional magnetic resonance imaging to record brain activity in 24 female patients with spider phobia who were administered either 20 mg of cortisol or placebo while viewing pictures of spiders. Fourteen healthy female participants were tested with the same task but without substance administration. Independent component analysis (ICA) performed during stimulus encoding identified the SN and DMN as exhibiting synchronized activation in diverse brain regions; thus, we examined the effects of cortisol on these networks. Furthermore, participants had to rate their level of fear at various time points. RESULTS: Glucocorticoids reduced phobic fear in patients with spider phobia. The ICA performed during stimulus encoding revealed that activity in the SN and DMN was reduced in placebo-treated patients versus healthy controls. Brain activity in the SN, but not the DMN, was altered in cortisol- versus placebo-treated patients to a level that was similar to that observed in healthy controls. CONCLUSIONS: Activity in both the SN and DMN was reduced in patients with spider phobia. Cortisol administration altered the SN activity to a level that was comparable to that found in healthy controls. This alteration in SN activity might reflect the fear-reducing effects of glucocorticoids in phobia.

Predicting Subjective Affective Salience from Cortical Responses to Invisible Object Stimuli.

The affective value of a stimulus substantially influences its potency to gain access to awareness. Here, we sought to elucidate the neural mechanisms underlying such affective salience in a combined behavioral and fMRI experiment. Healthy individuals with varying degrees of spider phobia were presented with pictures of spiders and flowers suppressed from view by continuous flash suppression. Applying multivoxel pattern analysis, we found that the average time that spider stimuli took relative to flowers to gain access to awareness in each participant could be decoded from fMRI signals evoked by suppressed spider versus flower stimuli in occipitotemporal and orbitofrontal cortex. Our results indicate neural signals during unconscious processing of complex visual information in orbitofrontal and ventral visual areas predict access to awareness of this information, suggesting a crucial role for these higher-level cortical regions in mediating affective salience.

Evaluation of the therapeutic response by (99m)Tc-ECD-SPET in a female with non-organic depression, generalized anxiety and heterophobia.

This is the case of a 33 years old female patient who was diagnosed with depression and heterophobia, which progressed to generalized anxiety according to the International Statistical Classification of Diseases and Health Related Problems, 10th Revision (ICD-10), Version for 2010 diagnostic criteria. The clinical symptoms of the patient were significantly improved after effective treatment. The patient underwent before and after treatment 99mTc-ethyl cysteinate dimmer ((99m)Tc-ECD) brain single-photon emission tomography (SPET). A great improvement in regional cerebral blood flow was found after treatment. In conclusion, this case highlights the value of brain perfusion SPET scan in providing objective imaging evidence of diagnosis and treatment evaluation in a patient with non-organic mental disorder.

Supporting claustrophobic patients during magnetic resonance imaging examination- the radiographer perspective.

INTRODUCTION: Some patients cannot complete their magnetic resonance imaging (MRI) examinations because of claustrophobia. Evidence showed that supportive instruction is an effective intervention used to assist claustrophobic patients in MRI. However, the effectiveness of this intervention depends on the experience and education level of the MRI radiographer. This study aimed to understand the views of MRI radiographers on supporting claustrophobic patients and develop a guide to improve the effectiveness of the intervention. METHODS: A qualitative descriptive approach utilising focus group discussion was considered suitable. A purposive sampling method was used to enrol eligible participants into the study. The study was advertised in print newspapers and on social media platforms. There were seven MRI radiographers in the focus group discussion. The conversation was recorded and transcribed for analysis, with content analysis employed to group the data into relevant codes and categories. RESULTS: The radiographer's understanding of claustrophobia and knowledge of the interventions used to support claustrophobic patients were the key elements that influenced claustrophobic patients' experience in MRI. However, there were some factors inhibiting the radiographer's ability to support these patients. These factors include insufficient appointment slots, availability of supportive tools and support with developing communication skills. CONCLUSION: Communication and identifying anxiety signs are essential for MRI radiographers to address patient anxiety during examinations. This might increase the MRI examination completion rate and give the patient a positive experience in the department. IMPLICATIONS FOR PRACTICE: MRI radiographers can better understand how to support claustrophobic patients. Also, the guide developed from the data could help improve consistency in the use of supportive instruction in clinical practice.

Association between resting-state connectivity patterns in the defensive system network and treatment response in spider phobia-a replication approach.

Although highly effective on average, exposure-based treatments do not work equally well for all patients with anxiety disorders. The identification of pre-treatment response-predicting patient characteristics may enable patient stratification. Preliminary research highlights the relevance of inhibitory fronto-limbic networks as such. We aimed to identify pre-treatment neural signatures differing between exposure treatment responders and non-responders in spider phobia and to validate results through rigorous replication. Data of a bi-centric intervention study comprised clinical phenotyping and pre-treatment resting-state functional connectivity (rsFC) data of n = 79 patients with spider phobia (discovery sample) and n = 69 patients (replication sample). RsFC data analyses were accomplished using the Matlab-based CONN-toolbox with harmonized analyses protocols at both sites. Treatment response was defined by a reduction of >30% symptom severity from pre- to post-treatment (Spider Phobia Questionnaire Score, primary outcome). Secondary outcome was defined by a reduction of >50% in a Behavioral Avoidance Test (BAT). Mean within-session fear reduction functioned as a process measure for exposure. Compared to non-responders and pre-treatment, results in the discovery sample seemed to indicate that responders exhibited stronger negative connectivity between frontal and limbic structures and were characterized by heightened connectivity between the amygdala and ventral visual pathway regions. Patients exhibiting high within-session fear reduction showed stronger excitatory connectivity within the prefrontal cortex than patients with low within-session fear reduction. Whereas these results could be replicated by another team using the same data (cross-team replication), cross-site replication of the discovery sample findings in the independent replication sample was unsuccessful. Results seem to support negative fronto-limbic connectivity as promising ingredient to enhance response rates in specific phobia but lack sufficient replication. Further research is needed to obtain a valid basis for clinical decision-making and the development of individually tailored treatment options. Notably, future studies should regularly include replication approaches in their protocols.

Harnessing ChatGPT dialogues to address claustrophobia in MRI - A radiographers' education perspective.

INTRODUCTION: The healthcare sector invests significantly in communication skills training, but not always with satisfactory results. Recently, generative Large Language Models, have shown promising results in medical education. This study aims to use ChatGPT to simulate radiographer-patient conversations about the critical moment of claustrophobia management during MRI, exploring how Artificial Intelligence can improve radiographers' communication skills. METHODS: This study exploits specifically designed prompts on ChatGPT-3.5 and ChatGPT-4 to generate simulated conversations between virtual claustrophobic patients and six radiographers with varying levels of work experience focusing on their differences in model size and language generation capabilities. Success rates and responses were analysed. The methods of radiographers in convincing virtual patients to undergo MRI despite claustrophobia were also evaluated. RESULTS: A total of 60 simulations were conducted, achieving a success rate of 96.7% (58/60). ChatGPT-3.5 exhibited errors in 40% (12/30) of the simulations, while ChatGPT-4 showed no errors. In terms of radiographers' communication during the simulations, out of 164 responses, 70.2% (115/164) were categorized as "Supportive Instructions," followed by "Music Therapy" at 18.3% (30/164). Experts mainly used "Supportive Instructions" (82.2%, 51/62) and "Breathing Techniques" (9.7%, 6/62). Intermediate participants favoured "Music Therapy" (26%, 13/50), while Beginner participants frequently utilized "Mild Sedation" (15.4%, 8/52). CONCLUSION: The simulation of clinical scenarios via ChatGPT proves valuable in assessing and testing radiographers' communication skills, especially in managing claustrophobic patients during MRI. This pilot study highlights the potential of ChatGPT in preclinical training, recognizing different training needs at different levels of professional experience. IMPLICATIONS FOR PRACTICE: This study is relevant in radiography practice, where AI is increasingly widespread, as it explores a new way to improve the training of radiographers.

Radiographer's confidence in managing patients with claustrophobia during magnetic resonance imaging.

INTRODUCTION: Claustrophobia is a major problem experienced by some patients referred for magnetic resonance imaging (MRI). This results in significant costs and delays to healthcare service provision due to appointment cancellations or patients' inability to complete MRI examinations. Radiographers may use several strategies to effectively manage patients with claustrophobia during MRI. This study aimed to determine radiographer's confidence in managing patients with claustrophobia and evaluate the perceived effectiveness of the intervention approaches employed. METHODS: With institutional ethical approval, an online survey was conducted (15th September to 9th November 2020) among Kuwaiti MRI radiographers. The survey was designed to obtain information relating to participant demographics and the perceived confidence of radiographers in their use of interventions to manage claustrophobia during MRI procedures. Data obtained were analysed using the Statistical Package for the Social Sciences (v.26). RESULTS: A total of 144 valid responses were obtained. Of the respondents, 82% (n = 118) were confident that they could support claustrophobic patients during MRI examinations. Almost all respondents (97.9%, n = 141) employed various claustrophobia reduction and relaxation techniques to improve patient experience and increase scan completion rates. There was a significant association between radiographer's level of education (rs = +0.18, p = 0.028) and experience (rs = +0.33, p < 0.001) with their confidence managing claustrophobic patients. While participating radiographers considered lectures and training the most effective methods to improve their skills in managing such patients, educating claustrophobic patients prior to their MRI scan was the most effective technique for facilitating scan completion. CONCLUSION: Kuwaiti MRI radiographers are confident in applying different claustrophobic management techniques to improve patient compliance. Patient education, through supportive discussion, prior to their MRI examination was identified as the most effective intervention for managing claustrophobia. IMPLICATIONS FOR PRACTICE: Patient education before MRI examination is necessary to enhance their experience and optimise scan completion rates. In addition, it is essential that MR radiographers develop their practical competence in supporting patients with claustrophobia during their scans.

Altered spontaneous neural activity in frontal and visual regions in patients with acrophobia.

BACKGROUND: Acrophobia is a prevalent type of specific phobia, which frequently leads to functional impairments and occupational limitations. However, the neural pathology of acrophobia is still largely unknown. METHODS: 26 acrophobic patients and 30 healthy controls were enrolled in this study. All participants underwent a resting-state fMRI scan. Severity of symptoms was evaluated using self-report and behavioral measures. The regional homogeneity (ReHo) and seed-based functional connectivity (FC) were then examined. RESULTS: Compared to controls, acrophobic patients demonstrated higher ReHo in the right fusiform gyrus and lower ReHo in the bilateral superior frontal gyrus. Lower FC of right fusiform gyrus-bilateral caudate, right fusiform gyrus-right parahippocampal gyrus, and left medial superior frontal gyrus-left cuneus was also found in the acrophobia group. Additionally, there were negative correlations between behavior avoidance scores and FC of right fusiform gyrus- right parahippocampal gyrus (r = -0.42, p = 0.04) and between scores of the 7-item generalized anxiety disorder scale and FC of left medial superior frontal gyrus- left cuneus (r = -0.40, p = 0.049) in the acrophobia group. LIMITATIONS: Owing to the cross-sectional design, it was unclear whether the functional abnormalities found in the acrophobic patients were related to state or trait effects. CONCLUSIONS: Preliminary results indicated that acrophobic patients revealed abnormal brain function in orbitofrontal cortex, medial prefrontal cortex, and visual regions. These abnormalities may be helpful in understanding the possible neurobiological mechanism of acrophobia and may serve as potential intervention and prevention targets.

Radiographer Perspectives on current occurrence and management of claustrophobia in MRI.

INTRODUCTION: Magnetic Resonance Imaging (MRI) is well known to be a source of anxiety for patients, commonly appearing as claustrophobia. One of the main reasons for this is due to the physical nature of the scanner itself. Despite technological improvements, there is lacking evidence on whether these improvements have resulted in a reduction in claustrophobia and anxiety in the clinical setting. Background anxiety associated with the current COVID-19 pandemic may also have shown an increase in prevalence. Therefore, the aim of this study was to survey MRI radiographers on their perspectives on the occurrence and management of claustrophobia in modern day clinical practice. METHODS: Following ethical approval, an online survey was used to gather the opinions of MRI radiographers. This used closed ranking questions as well as open responses to gain insight into how this issue may be presenting in practice, preferences in management, and barriers to providing support. RESULTS: Responses provide an up-to-date view on how radiographers perceive both displays of anxiety and associated impacts on patient outcome, the considered sources of anxiety, the use and effectiveness of support strategies, barriers to providing this support, and views on how COVID-19 has impacted on practice. CONCLUSION: The study provides a current view from radiographers on their experience of claustrophobia in practice. It shows that this remains a regular part of practice within the modality. Therefore, for MRI radiographers managing this is an essential component of their role. Communication and interaction with the patient are recognised as important, although time is a barrier to always being able to provide patient centred care. IMPLICATIONS FOR PRACTICE: Ongoing support is needed for both patients and radiographers to improve experience within MRI.

The veins of the nucleus dentatus: anatomical and radiological findings.

The veins of the dentate nucleus are composed of several channels draining the external surface and one single vein draining the internal surface. We analyzed specimens of the human cerebellum and described the central vein of the nucleus dentatus as the main venous outflow of the nucleus. The central vein of the nucleus dentatus is formed by a network of smaller vessels draining the sinuosities of the gray matter; it emerges from the hilum of the nucleus and runs along the superior cerebellar peduncle, opening in the anterior vermian vein. We looked for this structure and for the surrounding veins on ultra-high-field (7 Tesla) MR, using susceptibility-weighted imaging. An anatomical and radiological description of the veins of the dentate nucleus is provided, with some remarks on the future clinical applications that these findings could provide.

Neurofunctional correlates of expressed vocal affect in social phobia.

We investigated the neural correlates of expressed vocal affect in patients with social phobia. A group of 36 patients performed an anxiogenic public-speaking task while regional cerebral blood flow (rCBF) was assessed using oxygen-15 positron emission tomography. The patients' speech was recorded and content masked using low-pass filtering (which obscures linguistic content but preserves nonverbal affective cues). The content-masked speech samples were then evaluated with regard to their level of vocally expressed nervousness. We hypothesized that activity in prefrontal and subcortical brain areas previously implicated in emotion regulation would be associated with the degree of expressed vocal affect. Regression analyses accordingly revealed significant negative correlations between expressed vocal affect and rCBF in inferior frontal gyrus, putamen, and hippocampus. Further, functional connectivity was revealed between inferior frontal gyrus and (a) anterior cingulate cortex and (b) amygdala and basal ganglia. We suggest that brain areas important for emotion regulation may also form part of a network associated with the modulation of affective prosody in social phobia.

Centromedial amygdala is more relevant for phobic confrontation relative to the bed nucleus of stria terminalis in patients with spider phobia.

Recent studies indicate differential involvement of the centromedial amygdala (CM) and the bed nucleus of the stria terminalis (BNST) during processing (anticipation and confrontation) of threat stimuli. Here, temporal predictability was shown to be a relevant factor. In this study, we want to investigate the relevance of these effects, which were found in healthy subjects, for anxiety disorders. Therefore, we investigated the differential involvement of CM and BNST in the anticipation and confrontation of phobic stimuli under variation of temporal predictability in spider phobia. 21 patients with spider phobia and 21 healthy controls underwent a temporally predictable/unpredictable phobic and neutral anticipation and confrontation paradigm using functional magnetic resonance imaging (fMRI) and ROI analyses. During the anticipation phase, healthy controls showed higher CM and BNST activity during the predictable compared with the unpredictable condition compared with the anxiety patients. During a confrontation phase that followed the anticipation phase, CM was more activated than BNST during the phobic compared with the neutral confrontation. While this effect was independent of threat predictability in patients, healthy controls showed higher activation in the CM compared with the BNST only during the predictable spider confrontation compared with the predictable bird confrontation. The results contribute to a better understanding of the separate roles of the CM and BNST during phobic processes. The CM was found to be more relevant to phobic confrontation in patients with spider phobia compared with the BNST.