***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Little is known about the effects of successful psychotherapy on brain function in subjects with anxiety disorders . The present study aim ed to identify changes in brain activation following cognitive-behavioral therapy ( CBT ) in subjects suffering from specific phobia . Using functional magnetic resonance imaging ( fMRI ) , brain activation to spider videos was measured in 28 spider phobic and 14 healthy control subjects . Phobics were r and omly assigned to a therapy-group ( TG ) and a waiting-list control group ( WG ) . Both groups of phobics were scanned twice . Between scanning sessions , CBT was given to the TG . Before therapy , brain activation did not differ between both groups of phobics . As compared to control subjects , phobics showed greater responses to spider vs. control videos in the insula and anterior cingulate cortex ( ACC ) . CBT  strongly reduced phobic symptoms in the TG while the WG remained behaviorally unchanged . In the second scanning session , a significant reduction of hyperactivity in the insula and ACC was found in the TG compared to the WG . These results propose that increased activation in the insula and ACC is associated with specific phobia , whereas an attenuation of these brain responses correlates with successful therapeutic intervention BACKGROUND Animal studies demonstrate that stress and negative affect enhance the release of the neuropeptide substance P ( SP ) , which binds to the neurokinin 1 ( NK1 ) receptor . This positron emission tomography ( PET ) study evaluated how the activity in the SP-NK1 receptor system in the amygdala was affected by fear provocation in subjects with specific phobia . METHODS Sixteen adult women with DSM-IV-defined specific phobia for either snakes or spiders but not both  viewed pictures of feared and non-feared animals while being PET-scanned for 60 min with the highly specific NK1 receptor antagonist [(11)C]GR205171 as the labeled PET tracer . RESULTS The uptake of the labeled NK1 receptor antagonist was significantly reduced in the right amygdala during phobic stimulation . In the left amygdala no significant differences were found between phobic and non-phobic conditions . There was a negative correlation in the right , but not left , amygdala between subjective anxiety ratings and NK1 tracer binding . CONCLUSIONS Fear provocation affects the SP-NK1 receptor system in the right amygdala . This reflects reduced NK1 receptor availability during fear and could mirror an increased release of endogenous substance Neurofunctional mechanisms underlying cognitive behavior therapy ( CBT ) are still not clearly understood . This functional magnetic resonance imaging ( fMRI ) study focused on changes in brain activation as a result of one-session CBT in patients suffering from spider phobia . Twenty-six female spider phobics and 25 non-phobic subjects were presented with spider pictures , generally disgust-inducing , generally fear-inducing and affectively neutral scenes in an initial fMRI session . Afterwards , the patients were r and omly assigned to either a therapy group ( TG ) or a waiting list group ( WG ) . The scans were repeated one week after the treatment or after a one-week waiting period . Relative to the non-phobic participants , the patients displayed increased activation in the amygdala and the fusiform gyrus as well as decreased activation in the medial orbitofrontal cortex ( OFC ) during the first exposure . The therapy effect consisted of increased medial OFC activity in the TG relative to the WG . Further , therapy-related reductions in experienced somatic anxiety symptoms were positively correlated with activation decreases in the amygdala and the insula . We conclude that successful treatment of spider phobia is primarily accompanied by functional changes of the medial OFC . This brain region is crucial for the self-regulation of emotions and the relearning of stimulus-reinforcement associations Forty-six patients with spider phobia , fulfilling the DSM-IV criteria for specific phobia , were assessed with behavioral , physiological and self-report measures . They were r and omly assigned to three group treatment conditions : ( 1 ) direct treatment ; ( 2 ) direct observation ; and ( 3 ) indirect observation . All treatments were carried out in large groups of eight patients , and consisted of one 3 hr session of massed exposure and modelling . The results showed that on the behavioral test , measures and the specific self-report measures of spider phobia the direct treatment was significantly better than direct observation and indirect observation , which did not differ . On the physiological measures and the psychopathology self-report measures there were significant pre-post improvements , but no differences between the groups . The effects were maintained or furthered at the one year follow-up assessment . The proportion of clinical ly significantly improved patients were , at post-treatment , 75 % in the direct treatment , 7 % in the direct observation , and 31 % in the indirect observation group . At follow-up , the corresponding figures were 75 , 14 , and 44 % , respectively . The conclusion that can be drawn is that direct treatment is the treatment of choice BACKGROUND Exposure-based therapy for anxiety disorders is believed to operate on the basis of fear extinction . Studies have shown acute administration of D-cycloserine ( DCS ) enhances fear extinction in animals and facilitates exposure therapy in humans , but the neural mechanisms are not completely understood . To date , no study has examined neural effects of acute DCS in anxiety-disordered population s. METHODS Two hours prior to functional magnetic resonance imaging scanning , 23 spider-phobic and 23 non-phobic participants were r and omized to receive DCS 100 mg or placebo . During scanning , participants viewed spider , butterfly , and Gaussian-blurred baseline images in a block- design paradigm . Diagnostic and treatment groups were compared regarding differential activations to spider versus butterfly stimuli . RESULTS In the phobic group , DCS enhanced prefrontal ( PFC ) , dorsal anterior cingulate ( ACC ) , and insula activations . For controls , DCS enhanced ventral ACC and cau date activations . There was a positive correlation between lateral PFC and amygdala activation for the placebo-phobic group . Reported distress during symptom provocation was correlated with amygdala activation in the placebo-phobic group and orbitofrontal cortex activation in the DCS-phobic group . CONCLUSIONS Results suggest that during initial phobic symptom provocation DCS enhances activation in regions involved in cognitive control and interoceptive integration , including the PFC , ACC , and insular cortices for phobic participants BACKGROUND The study aim ed to identify brain activation during direct and automatic processing of phobogenic stimuli in specific phobia . METHODS Responses to  phobia-related and neutral pictures ( spiders and mushrooms ) were measured by means of event-related functional magnetic resonance imaging during two different tasks . In the identification task , subjects were asked to identify the object ( spider or mushroom ) . In a dem and ing distraction task , subjects had to match geometric figures displayed in the foreground of the pictures . RESULTS Phobics showed greater responses to spiders versus mushrooms in the left amygdala , left insula , left anterior cingulate gyrus ( ACC ) , and left dorsomedial prefrontal cortex ( DMPFC ) during the identification task and in the left and right amygdala during the distraction task . All of these activations were also significantly increased compared to control subjects who did not show stronger brain activation to spiders versus mushrooms under any task condition . CONCLUSIONS Our findings propose specific neural correlates of automatic versus direct evaluation of phobia-relevant threat . While the amygdala , especially the right amygdala , seems to be crucially involved in automatic stimuli processing , activation of areas such as the insula , ACC and DMPFC is rather associated with direct threat evaluation and requires sufficient attentional re sources Previous imaging studies of obsessive-compulsive symptom states have implicated frontal-striatal and limbic regions in the pathophysiology of obsessive-compulsive disorder ( OCD ) . Functional imaging studies , however , have yielded inconsistent results , presumably due to method ological differences ( patient inclusion criteria , stimulus paradigm , imaging technique , and absence of control groups ) . In the present study , r and omized presentation of contamination-related and neutral visual stimuli was used to investigate the neurophysiological correlates of contamination fear in a group of medication-free OCD patients with washing behaviors and healthy controls . A total of 21 subjects ( 11 OCD patients and 10 healthy controls ) were scanned using H(2)(15)O positron emission tomography ( PET ) . Subjects were presented with pictures of clean and dirty surroundings and were requested to make indoor/outdoor decisions to control for attention differences . State anxiety and obsessionality were rated after each scan using visual analogue scales . Main effects of stimulus type ( contamination vs. neutral ) were found in bilateral occipital cortex in both groups . A significant group interaction effect was observed in the left amygdala reflecting enhanced activity in response to contamination stimuli in OCD patients . Sensitization effects were observed in the right amygdala in the OCD group ; these paralleled an increase in levels of distress and obsessionality as well as a decrease in dorsolateral prefrontal activity . The findings of the present study are consistent with the hypothesis of decreased frontal-striatal control of limbic structures , specifically the amygdala , result ing in an inadequate fear response in OCD patients with contamination fear This study evaluated the efficacy of behavioral and cognitive-behavioral one-session exposure treatment procedures with and without programmed generalization for participants with small animal phobias . Forty participants were r and omly assigned to the treatment  and  generalization conditions . Both treatments produced significant improvements from pre-test to post-test and these results were maintained for 1 year . The treatment effect sizes ranged from large to very large across behavioral , self-report , and subjectively rated measures . Participants in the behavioral treatment condition reported that the treatment was significantly more intrusive than participants in the cognitive-behavioral treatment group . The programmed generalization condition did not produce additional measured benefit . The results are discussed in terms of the overall effectiveness of one-session exposure treatment components for small animal phobias OBJECTIVE This study investigated the neural substrates of implicit sequence learning in subjects with and without small animal phobia , in a follow-up to analogous studies of obsessive-compulsive disorder ( OCD ) . METHOD Ten subjects with specific phobia and 10 healthy comparison subjects were studied by using a serial reaction time task paradigm and functional magnetic resonance imaging . RESULTS A main effect of condition ( implicit sequence learning versus r and om sequence ) was observed across diagnostic groups in the right striatum , as well as in other regions . In the striatum , the a priori region of interest , there were no significant effects of diagnosis or the interaction of diagnosis and condition . CONCLUSIONS Brain activation in the striatum of subjects with specific phobia does not significantly differ from that of normal comparison subjects during implicit sequence learning . This suggests different pathophysiological mechanisms for specific phobia in contrast to OCD , in which deficient striatal recruitment has been reproducibly found with this paradigm . This approach offers promise for demonstrating diagnostic specificity across different neuropsychiatric disorders based on the presence or absence of deficient striatal activation We investigated central nervous system correlates of simple phobic fear . Regional cerebral blood flow ( rCBF ) was measured using positron emission tomography ( PET ) in eight volunteers with symptomatic spider phobia that were exposed to visual phobogenic and neutral stimuli . Diazepam ( 0.1 mg/kg body weight i.v . ) or placebo was administered under double-blind conditions after initial PET scans . The PET scans were then repeated . The presence of fear was confirmed by rating procedures and increased number of nonspecific electrodermal fluctuations and by higher heart rate during phobic than during neutral stimulation . Phobic as compared to neutral stimulation elevated the regional to whole brain ( relative ) CBF in the secondary visual cortex but reduced relative rCBF in the hippocampus , prefrontal , orbitofrontal , temporopolar , and posterior cingulate cortex . Diazepam treatment did not affect the relative rCBF or the subjective or physiological fear indices . The observed rCBF pattern replicates our previous findings in snake phobics ( M. Fredrikson et al. [ 1993 ] Psychophysiology , 30 , 127 - 131 ; G. Wik et al. [ 1993 ] Psychiatry Research ( Neuroimaging ) , 50 , 15 - 24 ) and indicates that fear and anxiety affect cortical areas outside the classic limbic system areas Positron emission tomography was employed to contrast the brain activation pattern in patients with obsessive-compulsive disorder ( OCD ) to that of matched control subjects while they performed an implicit learning task . Although patients and control subjects evidence d comparable learning , imaging data from control subjects indicated bilateral inferior striatal activation , whereas OCD patients did not activate right or left inferior striatum and instead showed bilateral medial temporal activation . The findings further implicate corticostriatal dysfunction in obsessive-compulsive disorder . Furthermore , when OCD patients are confronted with stimuli that call for recruitment of corticostriatal systems , they instead appear to access brain regions normally associated with explicit ( conscious ) information processing Fifty-two patients with spider phobia , fulfilling the DSM-III-R criteria for simple phobia , were assessed with behavioral , physiological and self-report measures . They were r and omly assigned to five different treatment conditions : ( 1 ) one session therapist-directed exposure ( maximum 3 hours ) , ( 2 ) specific manual-based treatment in the home , ( 3 ) specific manual-based treatment at the clinic , ( 4 ) general manual-based treatment in the home and ( 5 ) general manual-based treatment at the clinic . The results show that therapist-directed one-session treatment was significantly more effective than three of the manual-based treatments , both at the post-treatment and follow-up stages . Specific manual-based treatment at the clin 
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RESULT The search showed that studies in this area were published recently and that the neuroanatomic substrate of SP has not yet been consoli date d. CONCLUSION In spite of method ological differences among studies , results converge to a greater activation in the insula , anterior cingulate cortex , amygdala , and prefrontal and orbitofrontal cortex of patients exposed to phobia-related situations compared to controls .
These findings support the hypotheses of the hyperactivation of a neuroanatomic structural network involved in SP