Altered cerebral blood flow patterns associated with pathologic worry in the elderly

Background: Generalized anxiety disorder (GAD) is the most prevalent anxiety disorder among the elderly and has high functional and cognitive morbidity. However, late‐life GAD is relatively understudied and its functional neuroanatomy is uncharted. Several imaging studies have suggested abnormalities in the cognitive control systems of emotion regulation in anxiety disorders in young adults. The aim of this study was to examine the neural correlates of emotion regulation in late‐life GAD. Method: We compared 7 elderly GAD subjects and 10 elderly nonanxious comparison subjects using functional MRI. Regional cerebral blood flow (rCBF) was measured using pulsed arterial spin labeling perfusion MRI at rest and during an emotion regulation paradigm. Results: Relative to the rest condition, elderly nonanxious comparison subjects had increased rCBF during worry induction (WI) in the right insula, bilateral amygdala, and associative temporooccipital areas. Elderly GAD subjects had increased rCBF during WI in the associative temporooccipital areas, but not in the insula or the amygdala. During worry suppression (WS), elderly nonanxious comparison subjects had increased rCBF in the prefrontal cortex (PFC) and dorsal ACC. Elderly GAD subjects had no changes in rCBF during WS in the PFC. Conclusions: When attempting to regulate their emotional responses, elderly anxious subjects failed to activate prefrontal regions involved in the downregulation of negative emotions. These results, showing that elderly anxious subjects are not effectively engaging the PFC in suppressing worry, may be clinically relevant for developing personalized therapeutic strategies for the treatment of late‐life GAD. Depression and Anxiety 28:202–209, 2011. © 2011 Wiley‐Liss, Inc.     

Pain networks from the inside: Spatiotemporal analysis of brain responses leading from nociception to conscious perception

Conscious perception of painful stimuli needs the contribution of an extensive cortico‐subcortical network, and is completed in less than one second. While initial activities in operculo‐insular and mid‐cingulate cortices have been extensively assessed, the activation timing of most areas supporting conscious pain has barely been studied. Here we used intracranial EEG to investigate the dynamics of 16 brain regions (insular, parietal, prefrontal, cingulate, hippocampal and limbic) during the first second following nociceptive‐specific laser pulses. Three waves of activation could be defined according to their temporal relation with conscious perception, ascertained by voluntary motor responses. Pre‐conscious activities were recorded in the posterior insula, operculum, mid‐cingulate and amygdala. Antero‐insular, prefrontal and posterior parietal activities started later and developed during time‐frames consistent with conscious voluntary reactions. Responses from hippocampus, perigenual and perisplenial cingulate developed latest and persisted well after conscious perception occurred. Nociceptive inputs reach simultaneously sensory and limbic networks, probably through parallel spino‐thalamic and spino‐parabrachial pathways, and the initial limbic activation precedes conscious perception of pain. Access of sensory information to consciousness develops concomitant to fronto‐parietal activity, while late‐occurring responses in the hippocampal region, perigenual and posterior cingulate cortices likely underlie processes linked to memory encoding, self‐awareness and pain modulation. Hum Brain Mapp 37:4301–4315, 2016. © 2016 Wiley Periodicals, Inc.     

Anxiety sensitivity correlates with two indices of right anterior insula structure in specific animal phobia

Background: Anxiety sensitivity (AS) is a dispositional trait involving fear of anxiety‐related symptoms. Functional imaging research suggests that the activity of the anterior insular cortex, particularly the right insula, may both mediate AS and play a role in the pathophysiology of phobias. However, no imaging studies have examined whether AS relates to insula morphology. We examined whether AS was significantly correlated with right anterior insula volume and thickness among adults with specific animal phobia (SAP) and healthy comparison (HC) subjects. Methods: Nineteen adults with SAP and 20 demographically group‐matched HC subjects underwent magnetic resonance imaging at 3 Tesla. Subjects also completed the Anxiety Sensitivity Index (ASI). Regression and correlation analyses examined ASI scores in relation to anterior and posterior insular cortex volume and thickness within and across subject groups. Results: SAP subjects had significantly higher ASI scores than HC, but did not differ in terms of insula volumes or thickness. ASI scores predicted right anterior insula thickness in SAP but not HC subjects, and right anterior insula volume in the sample as a whole. Correlations of ASI scores with the anterior and posterior insula volume and thickness were not significant in either group. Conclusions: These findings suggest that the right anterior insular cortex size is a neural substrate of AS within specific phobia, rather than an independent diagnostic marker of the disorder. Future investigations should examine whether heightened AS represents a shared intermediate phenotype across anxiety disorders, manifesting functionally as increased insular reactivity and clinically as a fear of anxiety symptoms. Depression and Anxiety, 2010. © 2010 Wiley‐Liss, Inc.     

Anxiety positive subjects show altered processing in the anterior insula during anticipation of negative stimuli

Prior neuroimaging studies support the hypothesis that anticipation, an important component of anxiety, may be mediated by activation within the insular and medial prefrontal cortices including the anterior cingulate cortex. However, there is an insufficient understanding of how affective anticipation differs across anxiety groups in emotional brain loci and networks. We examined 14 anxiety positive (AP) and 14 anxiety normative (AN) individuals completing an affective picture anticipation task during functional magnetic resonance imaging (fMRI). Brain activation was examined across groups for cued anticipation (to aversive or pleasant stimuli). Both groups showed greater activation in the bilateral anterior insula during cued differential anticipation (i.e., aversive vs. pleasant), and activation on the right was significantly higher in AP compared to AN subjects. Functional connectivity showed that the left anterior insula was involved in a similar network during pleasant anticipation in both groups. The left anterior insula during aversive and the right anterior insula during all anticipation conditions coactivated with a cortical network consisting of frontal and parietal lobes in the AP group to a greater degree. These results are consistent with the hypothesis that anxiety is related to greater anticipatory reactivity in the brain and that there may be functional asymmetries in the brain that interact with psychiatric traits.     

Altered regional cerebral blood flow in obstructive sleep apnea is associated with sleep fragmentation and oxygen desaturation

Altered cerebral perfusion has been reported in obstructive sleep apnea (OSA). Using dynamic susceptibility contrast MRI, we compared cerebral perfusion between male OSA patients and male healthy reference subjects and assessed correlations of perfusion abnormalities of OSA patients with sleep parameters and neuropsychological deficits at 3 T MRI, polysomnography and neuropsychological tests in 68 patients with OSA and 21 reference subjects. We found lower global and regional cerebral blood flow and cerebral blood volume, localized mainly in bilateral parietal and prefrontal cortices, as well as multiple focal cortical and deep structures related to the default mode network and attention network. In the correlation analysis between regional hypoperfusion and parameters of polysomnography, different patterns of regional hypoperfusion were distinctively associated with parameters of intermittent hypoxia and sleep fragmentation, which involved mainly parietal and orbitofrontal cortices, respectively. There was no association between brain perfusion and cognition in OSA patients in areas where significant association was observed in reference subjects, largely overlapping with nodes of the default mode network and attention network. Our results suggest that impaired cerebral perfusion in important areas of functional networks could be an important pathomechanism of neurocognitive deficits in OSA.     

Neural correlates of anxiety sensitivity during masked presentation of affective faces

Background: Anxiety Sensitivity (AS), the tendency to fear the thoughts, symptoms, and social consequences associated with the experience of anxiety, is associated with increased risk for developing anxiety disorders. Some evidence suggests that higher scores on the Anxiety Sensitivity Index (ASI), a measure of the AS construct, are associated with activation of the anterior insular cortex during overt emotion perception. Although the ASI provides subscale scores measuring Physical, Mental Incapacitation, and Social Concerns of AS, no study has examined the relationship between these factors and regional brain activation during affect processing. We hypothesized that insular responses to fear‐related stimuli would be primarily related to the Physical Concerns subscale of the ASI, particularly for a sample of subjects with specific phobias. Methods: Adult healthy controls (HC; n = 22) and individuals with specific phobia, small animal subtype (SAP; n = 17), completed the ASI and underwent functional magnetic resonance imaging while engaged in a backward‐masked affect perception task that presents emotional facial stimuli below the threshold of conscious perception. Results: Groups did not differ in ASI, state or trait anxiety scores, or insula activation. Total ASI scores were positively correlated with activation in the right middle/anterior insula for the combined sample and for the HC and SAP groups separately. Multiple regression analysis revealed that the relationship between AS and insular activation was primarily accounted for by Physical Concerns only. Conclusions: Findings support the hypothesized role of the right anterior insula in the visceral/interoceptive aspects of AS, even in response to masked affective stimuli. Depression and Anxiety 28:243–249, 2011. © 2011 Wiley‐Liss, Inc.     

Anxiety does not predict response to duloxetine in major depression: results of a pooled analysis of individual patient data from 11 placebo‐controlled trials

Background: Uncontrolled antidepressant trials suggest that anxious patients with major depressive disorder (MDD) are less responsive to antidepressant treatment than less anxious patients. The objective of this study is to determine whether specific antidepressant effects, estimated by drug‐placebo differences, are reduced in anxious depression during treatment of MDD with duloxetine. Methods: This is a retrospective secondary pooled analysis of all placebo‐controlled trials of duloxetine at therapeutic doses conducted by the sponsor in outpatients with nonpsychotic unipolar MDD, using the Hamilton Depression Rating Scale (HAMD). Anxious depression was defined by ≥7 on the anxiety/somatization factor of the HAMD. Response was defined as ≥50% improvement from baseline to endpoint on the HAMD. Remission was defined as an endpoint HAMD≤7. Analyses were performed in the intent‐to‐treat sample with at least one post‐treatment rating. Results: Eleven trials included 2,841 patients of whom 1,326 were classified as anxious and 1,515 as nonanxious. Change on the HAMD was greater with duloxetine than placebo in both anxious (9.91 versus 7.55, P<.001) and nonanxious (6.65 versus 5.23, P<.001) patients. Level of anxiety had no effect on the drug–placebo differences. Response and remission rates were significantly greater in duloxetine than placebo‐treated patients and drug–placebo differences were unaffected by anxious status. Use of HAMD items psychic and somatic anxiety to define anxious subgroups had similar outcomes. Conclusions: Duloxetine was more effective than placebo in achieving response and remission in both anxious and nonanxious patients. Anxious status did not affect the magnitude of the drug effect. Depression and Anxiety, 2010. © 2009 Wiley‐Liss, Inc.     

GABAA‐benzodiazepine receptor availability in smokers and nonsmokers: Relationship to subsyndromal anxiety and depression

Many smokers experience subsyndromal anxiety symptoms while smoking and during acute abstinence, which may contribute to relapse. We hypothesized that cortical gamma aminobutyric acid_A‐benzodiazepine receptor (GABA_A‐BZR) availability in smokers and nonsmokers might be related to the expression of subsyndromal anxiety, depressive, and pain symptoms. Cortical GABA_A‐BZRs were imaged in 15 smokers (8 men and 7 women), and 15 healthy age and sex‐matched nonsmokers, and 4 abstinent tobacco smokers (3 men; 1 woman) using [¹²³I]iomazenil and single photon emission computed tomography (SPECT). Anxiety and depressive symptoms were measured using the Spielberger's State‐Trait Anxiety Index (STAI) and the Center for Epidemiology Scale for Depressive Symptoms (CES‐D). The cold pressor task was administered to assess pain tolerance and sensitivity. The relationship between cortical GABA_A‐BZR availability, smoking status, and subsyndromal depression and anxiety symptoms, as well as pain tolerance and sensitivity, were evaluated. Surprisingly, there were no statistically significant differences in overall GABA_A‐BZR availability between smokers and nonsmokers or between active and abstinent smokers; however, cortical GABA_A‐BZR availability negatively correlated with subsyndromal state anxiety symptoms in nonsmokers but not in smokers. In nonsmokers, the correlation was seen across many brain areas with state anxiety [parietal (r = ?0.47, P = 0.03), frontal (r = ?0.46, P = 0.03), anterior cingulate (r = ?0.47, P = 0.04), temporal (r = ?0.47, P = 0.03), occipital (r = ?0.43, P = 0.05) cortices, and cerebellum (r = ?0.46, P = 0.04)], trait anxiety [parietal (r = ?0.72, P = 0.02), frontal (r = ?0.72, P = 0.02), and occipital (r = ?0.65, P = 0.04) cortices] and depressive symptoms [parietal (r = ?0.68; P = 0.02), frontal (r = ?0.65; P = 0.03), anterior cingulate (r = ?0.61; P = 0.04), and temporal (r = ?0.66; P = 0.02) cortices]. The finding that a similar relationship between GABA_A‐BZR availability and anxiety symptoms was not observed in smokers suggests that there is a difference in GABA_A‐BZR function, but not number, in smokers. Thus, while subsyndromal anxiety and depressive symptoms in nonsmokers may be determined in part by GABA_A‐BZR availability, smoking disrupts this relationship. Aberrant regulation of GABA_A‐BZR function in vulnerable smokers may explain why some smokers experience subsyndromal anxiety and depression. Synapse 63:1089–1099, 2009. © 2009 Wiley‐Liss, Inc.     

Altered brain function in persistent postural perceptual dizziness: A study on resting state functional connectivity

This study used resting state functional magnetic resonance imaging (rsfMRI) to investigate whole brain networks in patients with persistent postural perceptual dizziness (PPPD). We compared rsfMRI data from 38 patients with PPPD and 38 healthy controls using whole brain and region of interest analyses. We examined correlations among connectivity and clinical variables and tested the ability of a machine learning algorithm to classify subjects using rsfMRI results. Patients with PPPD showed: (a) increased connectivity of subcallosal cortex with left superior lateral occipital cortex and left middle frontal gyrus, (b) decreased connectivity of left hippocampus with bilateral central opercular cortices, left posterior opercular cortex, right insular cortex and cerebellum, and (c) decreased connectivity between right nucleus accumbens and anterior left temporal fusiform cortex. After controlling for anxiety and depression as covariates, patients with PPPD still showed decreased connectivity between left hippocampus and right inferior frontal gyrus, bilateral temporal lobes, bilateral insular cortices, bilateral central opercular cortex, left parietal opercular cortex, bilateral occipital lobes and cerebellum (bilateral lobules VI and V, and left I–IV). Dizziness handicap, anxiety, and depression correlated with connectivity in clinically meaningful brain regions. The machine learning algorithm correctly classified patients and controls with a sensitivity of 78.4%, specificity of 76.9%, and area under the curve = 0.88 using 11 connectivity parameters. Patients with PPPD showed reduced connectivity among the areas involved in multisensory vestibular processing and spatial cognition, but increased connectivity in networks linking visual and emotional processing. Connectivity patterns may become an imaging biomarker of PPPD.     

Functional reorganization of the brain in recovery from striatocapsular infarction in man.

We used positron emission tomography (PET) to study organizational changes in the functional anatomy of the brain in 10 patients following recovery from striatocapsular motor strokes. Comparisons of regional cerebral blood flow maps at rest between the patients and 10 normal subjects revealed significantly lower regional cerebral blood flow in the basal ganglia, thalamus, sensorimotor, insular, and dorsolateral prefrontal cortices, in the brainstem, and in the ipsilateral cerebellum in patients, contralateral to the side of the recovered hand. These deficits reflect the distribution of dysfunction caused by the ischemic lesion. Regional cerebral blood flow was significantly increased in the contralateral posterior cingulate and premotor cortices, and in the caudate nucleus ipsilateral to the recovered hand. During the performance of a motor task by the recovered hand, patients activated the contralateral cortical motor areas and ipsilateral cerebellum to the same extent as did normal subjects. However, activation was greater than in normal subjects in both insulae; in the inferior parietal (area 40), prefrontal and anterior cingulate cortices; in the ipsilateral premotor cortex and basal ganglia; and in the contralateral cerebellum. The pattern of cortical activation was also abnormal when the unaffected hand, contralateral to the hemiplegia, performed the task. We showed that bilateral activation of motor pathways and the recruitment of additional sensorimotor areas and of other specific cortical areas are associated with recovery from motor stroke due to striatocapsular infarction. Activation of anterior and posterior cingulate and prefrontal cortices suggests that selective attentional and intentional mechanisms may be important in the recovery process. Our findings suggest that there is considerable scope for functional plasticity in the adult human cerebral cortex.     

Symptoms of anxiety disorders in normal children

The present study examined prevalence, expression, and developmental patterns of DSM-III-R anxiety disorder symptoms in 62 never-psychiatrically-ill children. Subclinical phobias and overanxious disorder symptoms were fairly common, while symptoms of other anxiety disorders were less common. Direction of sex and age differences was generally consistent with previous literature, but few reached statistical significance. Nonanxious and subclinically anxious subsamples of never-psychiatrically-ill subjects were compared on individual and family psychopathology. Subclinically anxious children showed greater individual and family psychopathology than nonanxious children, though differences decreased at 12-month follow-up. Anxiety as a normal developmental phenomenon is discussed.     

Using fMRI to dissociate sensory encoding from cognitive evaluation of heat pain intensity

Neuroimaging studies of painful stimuli in humans have identified a network of brain regions that is more extensive than identified previously in electrophysiological and anatomical studies of nociceptive pathways. This extensive network has been described as a pain matrix of brain regions that mediate the many interrelated aspects of conscious processing of nociceptive input such as perception, evaluation, affective response, and emotional memory. We used functional magnetic resonance imaging in healthy human subjects to distinguish brain regions required for pain sensory encoding from those required for cognitive evaluation of pain intensity. The results suggest that conscious cognitive evaluation of pain intensity in the absence of any sensory stimulation activates a network that includes bilateral anterior insular cortex/frontal operculum, dorsal lateral prefrontal cortex, bilateral medial prefrontal cortex/anterior cingulate cortex, right superior parietal cortex, inferior parietal lobule, orbital prefrontal cortex, and left occipital cortex. Increased activity common to both encoding and evaluation was observed in bilateral anterior insula/frontal operculum and medial prefrontal cortex/anterior cingulate cortex. We hypothesize that these two regions play a crucial role in bridging the encoding of pain sensation and the cognitive processing of sensory input.     

Altered global and regional brain mean diffusivity in patients with obstructive sleep apnea

Obstructive sleep apnea (OSA) is a common and progressive disorder accompanied by severe cardiovascular and neuropsychological sequelae, presumably induced by brain injury resulting from the intermittent hypoxia and cardiovascular processes accompanying the syndrome. However, whether the predominant brain tissue pathology is acute or chronic in newly‐diagnosed, untreated OSA subjects is unclear; this assessment is essential for revealing pathological processes. Diffusion tensor imaging (DTI)‐based mean diffusivity (MD) procedures can detect and differentiate acute from chronic pathology and may be useful to reveal processes in the condition. We collected four DTI series from 23 newly‐diagnosed, treatment‐naïve OSA and 23 control subjects, using a 3.0‐Tesla magnetic resonance imaging scanner. Mean diffusivity maps were calculated from each series, realigned, averaged, normalized to a common space, and smoothed. Global brain MD values for each subject were calculated using normalized MD maps and a global brain mask. Mean global brain MD values and smoothed MD maps were compared between groups by using analysis of covariance (covariate: age). Mean global brain MD values were significantly reduced in OSA compared with controls (P = 0.01). Multiple brain sites in OSA, including medullary, cerebellar, basal ganglia, prefrontal and frontal, limbic, insular, cingulum bundle, external capsule, corpus callosum, temporal, occipital, and corona radiata regions showed reduced regional MD values compared with controls. The results suggest that global brain MD values are significantly reduced in OSA, with certain regional sites especially affected, presumably a consequence of axonal, glial, and other cell changes in those areas. The findings likely represent acute pathological processes in newly‐diagnosed OSA subjects. © 2012 Wiley Periodicals, Inc.     

Glasgow Anxiety Scale for people with an Intellectual Disability (GAS-ID): development and psychometric properties of a new measure for use with people with mild intellectual disability

Background Self‐rating scales are widely used in general adult practice; however, there is no reliable and valid method for assessing state anxiety in people with intellectual disability (ID). The present study describes the development and psychometric evaluation of a new scale, the Glasgow Anxiety Scale for People with an Intellectual Disability (GAS‐ID). Methods First, an item pool was generated from focus groups, a review of the literature and clinician feedback. Secondly, a draft scale was administered to 19 anxious and 16 non‐anxious people with ID for further validation and appraisal of reliability. Thirdly, the scale was completed by 19 anxious, non‐ID people for cross‐validation with the Beck Anxiety Inventory (BAI). Finally, physiological concomitants were validated by pulse‐oximetry. Results The 27‐item GAS‐ID discriminated anxious from non‐anxious participants, had good test–retest reliability (r = 0.95) and internal consistency (α = 0.96), and was reasonably correlated with the BAI (ρ = 0.75). The correlation between the physiological subscale of the GAS‐ID and changes in pulse rate was moderately significant (ρ = 0.52). Conclusions This preliminary study suggests that the GAS‐ID offers a psychometrically robust and practical (5–10 min) approach to the appraisal of anxiety in this population.     

Differential functional brain network connectivity during visceral interoception as revealed by independent component analysis of fMRI time‐series

Influential theories of brain‐viscera interactions propose a central role for interoception in basic motivational and affective feeling states. Recent neuroimaging studies have underlined the insula, anterior cingulate, and ventral prefrontal cortices as the neural correlates of interoception. However, the relationships between these distributed brain regions remain unclear. In this study, we used spatial independent component analysis (ICA) and functional network connectivity (FNC) approaches to investigate time course correlations across the brain regions during visceral interoception. Functional magnetic resonance imaging (fMRI) was performed in thirteen healthy females who underwent viscerosensory stimulation of bladder as a representative internal organ at different prefill levels, i.e., no prefill, low prefill (100 ml saline), and high prefill (individually adapted to the sensations of persistent strong desire to void), and with different infusion temperatures, i.e., body warm (～37°C) or ice cold (4–8°C) saline solution. During Increased distention pressure on the viscera, the insula, striatum, anterior cingulate, ventromedial prefrontal cortex, amygdalo‐hippocampus, thalamus, brainstem, and cerebellar components showed increased activation. A second group of components encompassing the insula and anterior cingulate, dorsolateral prefrontal and posterior parietal cortices and temporal‐parietal junction showed increased activity with innocuous temperature stimulation of bladder mucosa. Significant differences in the FNC were found between the insula and amygdalo‐hippocampus, the insula and ventromedial prefrontal cortex, and the ventromedial prefrontal cortex and temporal‐parietal junction as the distention pressure on the viscera increased. These results provide new insight into the supraspinal processing of visceral interoception originating from an internal organ. Hum Brain Mapp 36:4438–4468, 2015. © 2015 Wiley Periodicals, Inc.     

Anxiety in Parkinson's disease is associated with changes in the brain fear circuit

BackgroundAnxiety is frequent in Parkinson's disease (PD) and has a negative impact on disease symptoms and quality of life. The underlying mechanisms remain largely unknown. The aim of this study was to identify anatomical and functional changes associated to PD-related anxiety by comparing the volume, shape and texture of the amygdala, the cortical thickness as well as the functional connectivity (FC) of the fear circuit in patients with and without clinically relevant anxiety.MethodsNon-demented PD patients were recruited, and anxiety was quantified using the Parkinson Anxiety Scale. Structural MRI was used to compare cortical thickness and amygdala structure and resting-state functional MRI to compare FC patterns of the amygdala and resting-state functional networks in both groups.ResultsWe included 118 patients: 34 with (A+) and 84 without (A-) clinically relevant anxiety. Clusters of cortical thinning were identified in the bilateral fronto-cingulate and left parietal cortices of the A+ group. The texture and the shape of the left amygdala was different in the A+ group but the overall volume did not differ between groups. FC between the amygdala and the whole brain regions did not differ between groups. The internetwork resting-state FC was higher between the “fear circuit” and salience network in the A+ group.ConclusionAnxiety in PD induces structural modifications of the left amygdala, atrophy of the bilateral fronto-cingulate and the left parietal cortices, and a higher internetwork resting-state FC between the fear circuit and the salience network.     

Alterations in amplitude of low frequency fluctuation in treatment‐naïve major depressive disorder measured with resting‐state fMRI

There are limited resting‐state functional magnetic resonance imaging (fMRI) studies in major depressive disorder (MDD). Of these studies, functional connectivity analyses are mostly used. However, a new method based on the magnitude of low frequency fluctuation (LFF) during resting‐state fMRI may provide important insight into MDD. In this study, we examined the amplitude of LFF (ALFF) within the whole brain during resting‐state fMRI in 30 treatment‐naïve MDD subjects and 30 healthy control (HC) subjects. When compared with HC, MDD subjects showed increased ALFF in the frontal cortex (including the bilateral ventral/dorsal anterior cingulate cortex, orbitofrontal cortex, premotor cortex, ventral prefrontal cortex, left dorsal lateral frontal cortex, left superior frontal cortex), basal ganglia (including the right putamen and left caudate nucleus), left insular cortex, right anterior entorhinal cortex and left inferior parietal cortex, together with decreased ALFF in the bilateral occipital cortex, cerebellum hemisphere, and right superior temporal cortex. These findings may relate to characteristics of MDD, such as excessive self‐referential processing and deficits in cognitive control of emotional processing, which may contribute to the persistent and recurrent nature of the disorder. Hum Brain Mapp 35:4979–4988, 2014. © 2014 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.     

Neural correlates of anticipation and processing of performance feedback in social anxiety

Fear of negative evaluation, such as negative social performance feedback, is the core symptom of social anxiety. The present study investigated the neural correlates of anticipation and perception of social performance feedback in social anxiety. High (HSA) and low (LSA) socially anxious individuals were asked to give a speech on a personally relevant topic and received standardized but appropriate expert performance feedback in a succeeding experimental session in which neural activity was measured during anticipation and presentation of negative and positive performance feedback concerning the speech performance, or a neutral feedback‐unrelated control condition. HSA compared to LSA subjects reported greater anxiety during anticipation of negative feedback. Functional magnetic resonance imaging results showed deactivation of medial prefrontal brain areas during anticipation of negative feedback relative to the control and the positive condition, and medial prefrontal and insular hyperactivation during presentation of negative as well as positive feedback in HSA compared to LSA subjects. The results indicate distinct processes underlying feedback processing during anticipation and presentation of feedback in HSA as compared to LSA individuals. In line with the role of the medial prefrontal cortex in self‐referential information processing and the insula in interoception, social anxiety seems to be associated with lower self‐monitoring during feedback anticipation, and an increased self‐focus and interoception during feedback presentation, regardless of feedback valence. Hum Brain Mapp 35:6023–6031, 2014. © 2014 Wiley Periodicals, Inc.     

Abnormal parietal cortex activation during working memory in schizophrenia: verbal phonological coding disturbances versus domain-general executive dysfunction

OBJECTIVE: The goal of this study was to determine whether the regions of the prefrontal and parietal cortices showing abnormal activation among individuals with schizophrenia during working memory tasks are associated with either 1) phonological coding processes that may be specific to verbal tasks (i.e., ventral prefrontal and parietal cortices) or 2) domain-general executive processes engaged by verbal and nonverbal tasks (i.e., dorsal prefrontal and parietal cortices). METHOD: The participants were 57 medicated individuals with schizophrenia and 120 healthy subjects. Functional magnetic resonance imaging was used to scan all participants during performance of verbal and nonverbal 2-back working memory tasks. RESULTS: In the healthy subjects there was similar bilateral dorsal prefrontal and inferior parietal cortex activation for both the verbal and nonverbal working memory tasks, but greater left ventral prefrontal and parietal cortex activation during verbal compared to nonverbal working memory. Individuals with schizophrenia showed bilateral deficits in dorsal frontal and parietal activation during both verbal and nonverbal working memory tasks. They also demonstrated the typical pattern of greater activity for verbal, as compared to nonverbal, working memory in ventral prefrontal and parietal regions, although they showed less verbal superiority in a left ventral prefrontal region. CONCLUSIONS: These results support the hypothesis that working memory deficits in individuals with schizophrenia reflect deficits in activation of brain regions associated with the central executive components of working memory rather than domain-specific storage buffers.     

Compensatory activation in fronto‐parietal cortices among HIV‐infected persons during a monetary decision‐making task

HIV infection can cause direct and indirect damage to the brain and is consistently associated with neurocognitive disorders, including impairments in decision‐making capacities. The tendency to devalue rewards that are delayed (temporal discounting) is relevant to a range of health risk behaviors. Making choices about delayed rewards engages the executive control network of the brain, which has been found to be affected by HIV. In this case–control study of 18 HIV‐positive and 17 HIV‐negative adults, we examined the effects of HIV on brain activation during a temporal discounting task. Functional MRI (fMRI) data were collected while participants made choices between smaller, sooner rewards and larger, delayed rewards. Choices were individualized based on participants' unique discount functions, so each participant experienced hard (similarly valued), easy (disparately valued), and control choices. fMRI data were analyzed using a mixed‐effects model to identify group‐related differences associated with choice difficulty. While there was no difference between groups in behavioral performance, the HIV‐positive group demonstrated significantly larger increases in activation within left parietal regions and bilateral prefrontal regions during easy trials and within the right prefrontal cortex and anterior cingulate during hard trials. Increasing activation within the prefrontal regions was associated with lower nadir CD4 cell count and risk‐taking propensity. These results support the hypothesis that HIV infection can alter brain functioning in regions that support decision making, providing further evidence for HIV‐associated compensatory activation within fronto‐parietal cortices. A history of immunosuppression may contribute to these brain changes. Hum Brain Mapp 37:2455–2467, 2016. © 2016 Wiley Periodicals, Inc .