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| 2. |
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| 3. |
- Persson, Jonas, et al.
(författare)
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Remembering our origin : Gender differences in spatial memory are reflected in gender differences in hippocampal lateralization
- 2013
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Ingår i: Behavioural Brain Research. - : Elsevier. - 0166-4328 .- 1872-7549. ; 256, s. 219-228
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Tidskriftsartikel (refereegranskat)abstract
- Gender differences in spatial memory favoring men are frequently reported, and the involvement of the hippocampus in these functions is well-established. However, little is known of whether this behavioral gender difference is mirrored in a gender difference in hippocampal function. Here we assessed hippocampal activity, using functional MRI, while 24 men and women moved through three-dimensional virtual mazes (navigation phase) of varying length, and at the end-point estimated the direction of the starting-point (pointing phase). Men were indeed more accurate than women at estimating direction, and this was especially true in longer mazes. Both genders activated the posterior hippocampus throughout the whole task. During the navigation phase, men showed a larger activation in the right hippocampus than women, while in the pointing phase, women showed a larger activation in the left hippocampus than men. Right-lateralized activation during the navigation phase was associated with greater task performance, and may reflect a spatial strategy that is beneficial in this task. Left-sided activation during the pointing phase might reflect a less efficient post hoc verbal recapitulation of the route. This study is the first to identify neural correlates of the commonly observed male advantage in recalling one's original position, and points to hippocampal lateralization as a possible explanation for this behavioral gender difference. (C) 2013 Elsevier B.V. All rights reserved.
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| 4. |
- Åhs, Fredrik, et al.
(författare)
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Medial temporal lobe resection attenuates superior temporal sulcus response to faces
- 2014
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Ingår i: Neuropsychologia. - : Elsevier BV. - 0028-3932 .- 1873-3514. ; 61, s. 291-298
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Tidskriftsartikel (refereegranskat)abstract
- Face perception depends on activation of a core face processing network including the fusiform face area, the occipital face area and the superior temporal sulcus (STS). The medial temporal lobe (MTL) is also involved in decoding facial expression and damage to the anterior MTL, including the amygdala, generally interferes with emotion recognition. The impairment in emotion recognition following anterior MTL injury can be a direct result from injured MTL circuitry, as well as an indirect result from decreased MTL modulation of areas in the core face network. To test whether the MTL modulates activity in the core face network, we used functional magnetic resonance imaging to investigate activation in the core face processing network in patients with right or left anterior temporal lobe resections (ATR) due to intractable epilepsy. We found reductions of face-related activation in the right STS after both right and left ATR together with impaired recognition of facial expressions. Reduced activity in the fusiform and the occipital face areas was also observed in patients after right ATR suggesting widespread effects on activity in the core face network in this group. The reduction in face-related STS activity after both right and left ATR suggests that MTL modulation of the STS may facilitate recognition of facial expression.
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| 7. |
- Bannbers, Elin, 1984-, et al.
(författare)
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Prefrontal activity during response inhibition decreases over time in the postpartum period
- 2013
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Ingår i: Behavioural Brain Research. - : Elsevier BV. - 0166-4328 .- 1872-7549. ; 241, s. 132-138
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Tidskriftsartikel (refereegranskat)abstract
- The postpartum period is characterized by complex hormonal changes, but human imaging studies in the postpartum period have thus far predominantly focused on the neural correlates of maternal behavior or postpartum depression, whereas longitudinal studies on neural correlates of cognitive function across the postpartum period in healthy women are lacking. The aim of this study was to longitudinally examine response inhibition, as a measure of executive function, during the postpartum period and its neural correlates in healthy postpartum women and non-postpartum controls. Thirteen healthy postpartum women underwent event-related functional magnetic resonance imaging while performing a Go/NoGo task. The first assessment was made within 48 h of delivery, and the second at 4-7 weeks postpartum. In addition, 13 healthy women examined twice during the menstrual cycle were included as non-postpartum controls. In postpartum women region of interest analyses revealed task-related decreased activations in the right inferior frontal gyrus, right anterior cingulate, and bilateral precentral gyri at the late postpartum assessment. Generally, postpartum women displayed lower activity during response inhibition in the bilateral inferior frontal gyri and precentral gyri compared to non-postpartum controls. No differences in performance on the Go/NoGo task were found between time-points or between groups. In conclusion, this study has discovered that brain activity in prefrontal areas during a response inhibition task decreases throughout the course of the first postpartum weeks and is lower than in non-postpartum controls. Further studies on the normal adaptive brain activity changes that occur during the postpartum period are warranted. (C) 2012 Elsevier B.V. All rights reserved.
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| 9. |
- Bannbers, Elin, et al.
(författare)
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The effect of premenstrual dysphoric disorder and menstrual cycle phase on brain activity during response inhibition
- 2012
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Ingår i: Journal of Affective Disorders. - : Elsevier BV. - 0165-0327 .- 1573-2517. ; 142:1-3, s. 347-350
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND:Premenstrual dysphoric disorder (PMDD) has generally not been associated with impulsive behavior. However, some studies suggest that women with PMDD have higher impulsivity scores than healthy controls and that brain activity during response inhibition may vary across the menstrual cycle. Therefore, our aim was to unravel potentially important cognitive aspects of PMDD by investigating brain activity during response inhibition in women with PMDD and healthy controls in relation to menstrual cycle phase.METHODS:Fourteen PMDD patients and 13 healthy controls performed a Go/NoGo task to measure brain activity during response inhibition by use of event-related functional magnetic resonance imaging.RESULTS:Women with PMDD displayed decreased activity during both menstrual cycle phases compared to healthy controls in several task-related parietal areas. A significant group by phase interactions was found in the left insula, driven by enhanced activity among healthy controls in the follicular phase and by enhanced insula activity during the luteal phase among PMDD patients.LIMITATIONS:The limitations of the present study are the relatively limited sample size, the relatively small number of NoGo trials and the lack of a baseline contrast for the NoGo trials.CONCLUSIONS:During response inhibition women with PMDD have reduced activity in areas associated with attention and motor function which is unrelated to menstrual cycle phase. Insular cortex activity, involved in both affective and cognitive processing, was significantly activated during the luteal phase among PMDD women. These findings are relevant for the understanding of how ovarian steroids influence mood symptoms in women.
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| 11. |
- Bas-Hoogendam, Janna Marie, et al.
(författare)
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Voxel-based morphometry multi-center mega-analysis of brain structure in social anxiety disorder
- 2017
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Ingår i: NeuroImage. - : Elsevier BV. - 2213-1582. ; 16, s. 678-688
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Tidskriftsartikel (refereegranskat)abstract
- Social anxiety disorder (SAD) is a prevalent and disabling mental disorder, associated with significant psychiatric co-morbidity. Previous research on structural brain alterations associated with SAD has yielded inconsistent results concerning the direction of the changes in gray matter (GM) in various brain regions, as well as on the relationship between brain structure and SAD-symptomatology. These heterogeneous findings are possibly due to limited sample sizes. Multi-site imaging offers new opportunities to investigate SAD-related alterations in brain structure in larger samples.An international multi-center mega-analysis on the largest database of SAD structural T1-weighted 3T MRI scans to date was performed to compare GM volume of SAD-patients (n = 174) and healthy control (HC)-participants (n = 213) using voxel-based morphometry. A hypothesis-driven region of interest (ROI) approach was used, focusing on the basal ganglia, the amygdala-hippocampal complex, the prefrontal cortex, and the parietal cortex. SAD-patients had larger GM volume in the dorsal striatum when compared to HC-participants. This increase correlated positively with the severity of self-reported social anxiety symptoms. No SAD-related differences in GM volume were present in the other ROIs. Thereby, the results of this mega-analysis suggest a role for the dorsal striatum in SAD, but previously reported SAD-related changes in GM in the amygdala, hippocampus, precuneus, prefrontal cortex and parietal regions were not replicated. Our findings emphasize the importance of large sample imaging studies and the need for meta-analyses like those performed by the Enhancing NeuroImaging Genetics through Meta-Analysis (ENIGMA) Consortium.
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| 12. |
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| 13. |
- Björkstrand, Johannes, et al.
(författare)
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Disruption of Memory Reconsolidation Erases a Fear Memory Trace in the Human Amygdala : An 18-Month Follow-Up.
- 2015
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 10:7, s. e0129393-
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Tidskriftsartikel (refereegranskat)abstract
- Fear memories can be attenuated by reactivation followed by disrupted reconsolidation. Using functional magnetic resonance imaging we recently showed that reactivation and reconsolidation of a conditioned fear memory trace in the basolateral amygdala predicts subsequent fear expression over two days, while reactivation followed by disrupted reconsolidation abolishes the memory trace and suppresses fear. In this follow-up study we demonstrate that the behavioral effect persists over 18 months reflected in superior reacquisition after undisrupted, as compared to disrupted reconsolidation, and that neural activity in the basolateral amygdala representing the initial fear memory predicts return of fear. We conclude that disrupting reconsolidation have long lasting behavioral effects and may permanently erase the fear component of an amygdala-dependent memory.
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| 14. |
- Costache, Madalina Elena, et al.
(författare)
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Higher- and lower-order personality traits and cluster subtypes in social anxiety disorder
- 2020
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Ingår i: PLOS ONE. - : PUBLIC LIBRARY SCIENCE. - 1932-6203. ; 15:4
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Tidskriftsartikel (refereegranskat)abstract
- Social anxiety disorder (SAD) can come in different forms, presenting problems for diagnostic classification. Here, we examined personality traits in a large sample of patients (N = 265) diagnosed with SAD in comparison to healthy controls (N = 164) by use of the Revised NEO Personality Inventory (NEO-PI-R) and Karolinska Scales of Personality (KSP). In addition, we identified subtypes of SAD based on cluster analysis of the NEO-PI-R Big Five personality dimensions. Significant group differences in personality traits between patients and controls were noted on all Big Five dimensions except agreeableness. Group differences were further noted on most lower-order facets of NEO-PI-R, and nearly all KSP variables. A logistic regression analysis showed, however, that only neuroticism and extraversion remained significant independent predictors of patient/control group when controlling for the effects of the other Big Five dimensions. Also, only neuroticism and extraversion yielded large effect sizes when SAD patients were compared to Swedish normative data for the NEO-PI-R. A two-step cluster analysis resulted in three separate clusters labelled Prototypical (33%), Introvert-Conscientious (29%), and Instable-Open (38%) SAD. Individuals in the Prototypical cluster deviated most on the Big Five dimensions and they were at the most severe end in profile analyses of social anxiety, self-rated fear during public speaking, trait anxiety, and anxiety-related KSP variables. While additional studies are needed to determine if personality subtypes in SAD differ in etiological and treatment-related factors, the present results demonstrate considerable personality heterogeneity in socially anxious individuals, further underscoring that SAD is a multidimensional disorder.
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| 15. |
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| 16. |
- Engman, Jonas, et al.
(författare)
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Age, sex and NK1 receptors in the human brain : A positron emission tomography study with [C-11]GR205171
- 2012
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Ingår i: European Neuropsychopharmacology. - : Elsevier BV. - 0924-977X .- 1873-7862. ; 22:8, s. 562-568
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Tidskriftsartikel (refereegranskat)abstract
- The substance P/neurokinin 1 (SP/NK1) system has been implicated in the processing of negative affect. Its role seems complex and findings from animal studies have not been easily translated to humans. Brain imaging studies on NK1 receptor distribution in humans have revealed an abundance of receptors in cortical, striatal and subcortical areas, including the amygdala. A reduction in NK1 receptors with increasing age has been reported in frontal, temporal, and parietal cortices, as well as in hippocampal areas. Also, a previous study suggests sex differences in cortical and subcortical areas, with women displaying fewer NK1 receptors. The present PET study explored NK1 receptor availability in men (n = 9) and women (n = 9) matched for age varying between 20 and 50 years using the highly specific NK1 receptor antagonist [11C]GR205171 and a reference tissue model with cerebellum as the reference region. Age by sex interactions in the amygdala and the temporal cortex reflected a lower NK1 receptor availability with increasing age in men, but not in women. A general age-related decline in NK1 receptor availability was evident in the frontal, temporal, and occipital cortices, as well as in the brainstem, caudate nucleus, and thalamus. Women had lower NK1 receptor availability in the thalamus. The observed pattern of NK1 receptor distribution in the brain might have functional significance for brain-related disorders showing age- and sex-related differences in prevalence.
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| 21. |
- Engman, Jonas, et al.
(författare)
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Amygdala subnuclei resting-state functional connectivity sex and estrogen differences
- 2016
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Ingår i: Psychoneuroendocrinology. - : Elsevier BV. - 0306-4530 .- 1873-3360. ; 63, s. 34-42
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Tidskriftsartikel (refereegranskat)abstract
- The amygdala is a hub in emotional processing, including that of negative affect. Healthy men and women have distinct differences in amygdala responses, potentially setting the stage for the observed sex differences in the prevalence of fear, anxiety, and pain disorders. Here, we examined how amygdala subnuclei resting-state functional connectivity is affected by sex, as well as explored how the functional connectivity is related to estrogen levels. Resting-state functional connectivity was measured using functional magnetic resonance imaging (fMRI) with seeds placed in the left and right laterobasal (LB) and centro-medial (CM) amygdala. Sex differences were studied in 48 healthy men and 48 healthy women, matched for age, while the association with estrogen was analyzed in a subsample of 24 women, for whom hormone levels had been assessed. For the hormone analyses, the subsample was further divided into a lower and higher estrogen levels group based on a median split. We found distinct sex differences in the LB and CM amygdala resting-state functional connectivity, as well as preliminary evidence for an association between estrogen levels and connectivity patterns. These results are potentially valuable in explaining why women are more afflicted by conditions of negative affect than are men, and could imply a mechanistic role for estrogen in modulating emotion.
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| 24. |
- Engman, Jonas
(författare)
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Hjärnan och känslor
- 2012
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 25. |
- Engman, Jonas, et al.
(författare)
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Hormonal Cycle and Contraceptive Effects on Amygdala and Salience Resting-State Networks in Women with Previous Affective Side Effects on the Pill.
- 2018
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Ingår i: Neuropsychopharmacology. - : Springer Science and Business Media LLC. - 0893-133X .- 1740-634X. ; 43:3, s. 555-563
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Tidskriftsartikel (refereegranskat)abstract
- The mechanisms linking ovarian hormones to negative affect are poorly characterized, but important clues may come from the examination of the brain's intrinsic organization. Here, we studied the effects of both the menstrual cycle and oral contraceptives (OCs) on amygdala and salience network resting-state functional connectivity using a double-blind, randomized, and placebo-controlled design. Hormone levels, depressive symptoms, and resting-state functional connectivity were measured in 35 healthy women (24.9±4.2 years) who had previously experienced OC-related negative affect. All participants were examined in the follicular phase of a baseline cycle and in the third week of the subsequent cycle during treatment with either a combined OC (30 μg ethinyl estradiol/0.15 mg levonorgestrel) or placebo. The latter time point targeted the midluteal phase in placebo users and steady-state ethinyl estradiol and levonorgestrel concentrations in OC users. Amygdala and salience network connectivity generally increased with both higher endogenous and synthetic hormone levels, although amygdala-parietal cortical connectivity decreased in OC users. When in the luteal phase, the naturally cycling placebo users demonstrated higher connectivity in both networks compared with the women receiving OCs. Our results support a causal link between the exogenous administration of synthetic hormones and amygdala and salience network connectivity. Furthermore, they suggest a similar, potentially stronger, association between the natural hormonal variations across the menstrual cycle and intrinsic network connectivity.
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