| 1. |
- Abelev, Betty, et al.
(författare)
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Underlying Event measurements in pp collisions at root s=0.9 and 7 TeV with the ALICE experiment at the LHC
- 2012
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Ingår i: Journal of High Energy Physics. - 1029-8479. ; :7
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Tidskriftsartikel (refereegranskat)abstract
- We present measurements of Underlying Event observables in pp collisions at root s = 0 : 9 and 7 TeV. The analysis is performed as a function of the highest charged-particle transverse momentum p(T),L-T in the event. Different regions are defined with respect to the azimuthal direction of the leading (highest transverse momentum) track: Toward, Transverse and Away. The Toward and Away regions collect the fragmentation products of the hardest partonic interaction. The Transverse region is expected to be most sensitive to the Underlying Event activity. The study is performed with charged particles above three different p(T) thresholds: 0.15, 0.5 and 1.0 GeV/c. In the Transverse region we observe an increase in the multiplicity of a factor 2-3 between the lower and higher collision energies, depending on the track p(T) threshold considered. Data are compared to PYTHIA 6.4, PYTHIA 8.1 and PHOJET. On average, all models considered underestimate the multiplicity and summed p(T) in the Transverse region by about 10-30%.
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| 2. |
- Blomberg, Rina, et al.
(författare)
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Aberrant resting-state connectivity of auditory, ventral attention/salience and default-mode networks in adults with attention deficit hyperactivity disorder
- 2022
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Ingår i: Frontiers in Neuroscience. - : Frontiers Media SA. - 1662-4548 .- 1662-453X. ; 16
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Tidskriftsartikel (refereegranskat)abstract
- Background Numerous resting-state studies on attention deficit hyperactivity disorder (ADHD) have reported aberrant functional connectivity (FC) between the default-mode network (DMN) and the ventral attention/salience network (VA/SN). This finding has commonly been interpreted as an index of poorer DMN regulation associated with symptoms of mind wandering in ADHD literature. However, a competing perspective suggests that dysfunctional organization of the DMN and VA/SN may additionally index increased sensitivity to the external environment. The goal of the current study was to test this latter perspective in relation to auditory distraction by investigating whether ADHD-adults exhibit aberrant FC between DMN, VA/SN, and auditory networks. Methods Twelve minutes of resting-state fMRI data was collected from two adult groups: ADHD (n = 17) and controls (n = 17); from which the FC between predefined regions comprising the DMN, VA/SN, and auditory networks were analyzed. Results A weaker anticorrelation between the VA/SN and DMN was observed in ADHD. DMN and VA/SN hubs also exhibited aberrant FC with the auditory network in ADHD. Additionally, participants who displayed a stronger anticorrelation between the VA/SN and auditory network at rest, also performed better on a cognitively demanding behavioral task that involved ignoring a distracting auditory stimulus. Conclusion Results are consistent with the hypothesis that auditory distraction in ADHD is linked to aberrant interactions between DMN, VA/SN, and auditory systems. Our findings support models that implicate dysfunctional organization of the DMN and VA/SN in the disorder and encourage more research into sensory interactions with these major networks.
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| 3. |
- Ekhtiari, Hamed, et al.
(författare)
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A methodological checklist for fMRI drug cue reactivity studies : development and expert consensus
- 2022
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Ingår i: Nature Protocols. - : Nature Portfolio. - 1754-2189 .- 1750-2799. ; 17:3, s. 567-595
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Tidskriftsartikel (refereegranskat)abstract
- Cue reactivity measured by functional magnetic resonance imaging is used in studies of substance-use disorders. This Consensus Statement is the result of a Delphi process to arrive at parameters that should be reported in describing these studies. Cue reactivity is one of the most frequently used paradigms in functional magnetic resonance imaging (fMRI) studies of substance use disorders (SUDs). Although there have been promising results elucidating the neurocognitive mechanisms of SUDs and SUD treatments, the interpretability and reproducibility of these studies is limited by incomplete reporting of participants characteristics, task design, craving assessment, scanning preparation and analysis decisions in fMRI drug cue reactivity (FDCR) experiments. This hampers clinical translation, not least because systematic review and meta-analysis of published work are difficult. This consensus paper and Delphi study aims to outline the important methodological aspects of FDCR research, present structured recommendations for more comprehensive methods reporting and review the FDCR literature to assess the reporting of items that are deemed important. Forty-five FDCR scientists from around the world participated in this study. First, an initial checklist of items deemed important in FDCR studies was developed by several members of the Enhanced NeuroImaging Genetics through Meta-Analyses (ENIGMA) Addiction working group on the basis of a systematic review. Using a modified Delphi consensus method, all experts were asked to comment on, revise or add items to the initial checklist, and then to rate the importance of each item in subsequent rounds. The reporting status of the items in the final checklist was investigated in 108 recently published FDCR studies identified through a systematic review. By the final round, 38 items reached the consensus threshold and were classified under seven major categories: Participants Characteristics, General fMRI Information, General Task Information, Cue Information, Craving Assessment Inside Scanner, Craving Assessment Outside Scanner and Pre- and Post-Scanning Considerations. The review of the 108 FDCR papers revealed significant gaps in the reporting of the items considered important by the experts. For instance, whereas items in the General fMRI Information category were reported in 90.5% of the reviewed papers, items in the Pre- and Post-Scanning Considerations category were reported by only 44.7% of reviewed FDCR studies. Considering the notable and sometimes unexpected gaps in the reporting of items deemed to be important by experts in any FDCR study, the protocols could benefit from the adoption of reporting standards. This checklist, a living document to be updated as the field and its methods advance, can help improve experimental design, reporting and the widespread understanding of the FDCR protocols. This checklist can also provide a sample for developing consensus statements for protocols in other areas of task-based fMRI.
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| 4. |
- Frost-Karlsson, Morgan, et al.
(författare)
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Neural processing of self-touch and other-touch in anorexia nervosa and autism spectrum condition
- 2022
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Ingår i: NeuroImage. - : Elsevier Science Ltd. - 2213-1582. ; 36
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: The tactile sense plays a crucial role in the development and maintenance of a functional bodily self. The ability to differentiate between self-and nonself-generated touch contributes to the perception of the bodies boundaries and more generally to self-other-distinction, both of which are thought be altered in anorexia nervosa (AN) and autism spectrum condition (AS). While it has been suggested that AN and AS are characterized by overlapping symptomatology, they might differ regarding body perception and self-other-distinction. Methods: Participants with a diagnosis of AN (n = 25), AS (n = 29), and a comparison group without diagnoses (n = 57) performed a self-other-touch task during functional brain imaging. In the experimental conditions, they stroked their own arm or were stroked on the arm by an experimenter. Results: As shown previously, the CG group showed lower activation or deactivation in response to self-touch compared to social touch from someone else. A main group effect was found in areas including somatosensory cortex, frontal and temporal gyri, insula, and subcortical regions. This was driven by increased activations in participants with AN, while participants in the AS group showed mostly comparable activations to the com-parison group. Conclusions: AN diagnosis was associated with an increased neural activity in response to both self-touch and social touch. Failure to attenuate self-touch might relate to altered predictions regarding the own body and reduced perception of bodily boundaries. Participants with an AS diagnosis were mostly comparable to the comparison group, potentially indicating unaltered tactile self-other-distinction.
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| 5. |
- Harel, Maayan, et al.
(författare)
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Repetitive Transcranial Magnetic Stimulation in Alcohol Dependence : A Randomized, Double-Blind, Sham-Controlled Proof-of-Concept Trial Targeting the Medial Prefrontal and Anterior Cingulate Cortices
- 2022
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Ingår i: Biological Psychiatry. - : Elsevier Science Inc. - 0006-3223 .- 1873-2402. ; 91:12, s. 1061-1069
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Alcohol addiction is associated with a high disease burden, and treatment options are limited. In a proof-of-concept study, we used deep repetitive transcranial magnetic stimulation (dTMS) to target circuitry associated with the pathophysiology of alcohol addiction. We evaluated clinical outcomes and explored associated neural signatures using functional magnetic resonance imaging. METHODS: This was a double-blind, randomized, sham-controlled trial. A total of 51 recently abstinent treatment-seeking patients with alcohol use disorder (moderate to severe) were randomized to sham or active dTMS, using an H7 coil targeting midline frontocortical areas, including the medial prefrontal and anterior cingulate cortices. Treatment included 15 sessions over 3 weeks, followed by five sessions over 3 months of follow-up. Each session delivered 100 trains of 30 pulses at 10 Hz. The primary predefined outcome was reduction in percentage of heavy drinking days, obtained using timeline follow-back interviews. Secondary analyses included self-reports of craving, ethyl glucuronide in urine, and brain imaging measures. RESULTS: Both craving after treatment and percentage of heavy drinking days during follow-up were significantly lower in the active versus sham control group (percentage of heavy drinking days = 2.9 +/- 0.8% vs. 10.6 +/- 1.9%, p = .037). Active dTMS was associated with decreased resting-state functional connectivity of the dorsal anterior cingulate cortex with the caudate nucleus and decreased connectivity of the medial prefrontal cortex to the subgenual anterior cingulate cortex. CONCLUSIONS: We provide initial proof-of-concept for dTMS targeting midline frontocortical structures as a treatment for alcohol addiction. These data strongly support a rationale for a full-scale confirmatory multicenter trial. Therapeutic benefits of dTMS appear to be associated with persistent changes in brain network activity.
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| 6. |
- Karlsson, Hanna, et al.
(författare)
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Acute effects of alcohol on social and personal decision making
- 2022
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Ingår i: Neuropsychopharmacology. - : SPRINGERNATURE. - 0893-133X .- 1740-634X. ; 47:4, s. 824-831
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Tidskriftsartikel (refereegranskat)abstract
- Social drinking is common, but it is unclear how moderate levels of alcohol influence decision making. Most prior studies have focused on adverse long-term effects on cognitive and executive function in people with alcohol use disorders (AUD). Some studies have investigated the acute effects of alcohol on decision making in healthy people, but have predominantly used small samples and focused on a narrow selection of tasks related to personal decision making, e.g., delay or probability discounting. Here, we conducted a large (n = 264), preregistered randomized placebo-controlled study (RCT) using a parallel group design, to systematically assess the acute effects of alcohol on measures of decision making in both personal and social domains. We found a robust effect of a 0.6 g/kg dose of alcohol on both moral judgment and altruistic behavior, but no effects on several measures of risk taking or waiting impulsivity. These findings suggest that alcohol at low to moderate doses selectively moderates decision making in the social domain, and promotes utilitarian decisions over those dictated by rule-based ethical principles (deontological). This is consistent with existing theory that emphasizes the dual roles of shortsighted information processing and salient social cues in shaping decisions made under the influence of alcohol. A better understanding of these effects is important to understand altered social functioning during alcohol intoxication.
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| 7. |
- Karlsson, Hanna, 1989-
(författare)
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From social drinking to alcohol addiction : Decision making and its neural substrates along a spectrum from social drinking to alcohol addiction
- 2024
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- For a minority of alcohol users, the initial sip of alcohol marks the start of a life-threatening process. This thesis studies cognitive mechanisms pertinent to alcohol addiction and its development, using a spectrum of individuals that range from healthy social drinkers, through people with hazardous use, to those suffering from alcohol addiction. Decision making can be altered in addiction, but less is known on the direct pharmacodynamic effects of alcohol intake in healthy people. Study 1 addressed decision making under the effects of moderate alcohol intoxication in healthy social drinkers using established behavioral economics tasks. The investigated processes encompassed both personal and social aspects of decision making. Within the personal domain, impulsivity and risk taking were investigated, while in the social domain, prosocial attitudes along with moral judgment were assessed. Moderate alcohol intoxication was found to impact only the social domain, leading to increased prosocial and utilitarian behaviors, but did not affect measures of impulsivity. Choosing alcohol over other natural rewards despite negative consequences is a central phenomenon of alcohol addiction. Two studies of this thesis investigated choice preference for alcohol compared to snack, using a cost manipulation paradigm, in light and heavy drinkers. Study 2 was a laboratory experiment whereas Study 3 was an imaging experiment for characterization of neural substrates. Cost was an important predictor of choice, as in both groups, alcohol choice was sensitive to cost in a parametric manner. This was mirrored in the brain by activity in value-based and salience regions, including orbitofrontal cortex and insula. In Study 2 we found that heavy drinkers showed generally higher alcohol choice preference and attenuated cost sensitivity. Failure to replicate this finding in Study 3, was possibly due to the artificial scanner environment. Craving is a key component in the cycle of addiction and a determinant of relapse, making it an important target for treatment interventions. Study 4 was a randomized sham-controlled trial using repetitive transcranial magnetic stimulation (rTMS) targeting the insula as a method to reduce craving and alcohol use in people suffering from alcohol addiction. An overall decrease in alcohol consumption and craving were seen, but did not differ between sham stimulation and rTMS targeting the insula. In summary, this thesis provides some insights into cognitive mechanisms related to alcohol addiction and processes that may be implicated in its development. During a moderate acute alcohol intoxication in healthy social drinkers, social decision-making is influenced, leading to increased utilitarian and altruistic behaviors. Thus, deficits in prosocial behaviors in people with alcohol addiction are unlikely to result from direct pharmacodynamic effects of alcohol, but are rather likely to reflect a selection of vulnerable individuals, consequences of the addictive process, or both. In individuals at risk of developing alcohol addiction, the sensitivity to the costs associated with choosing alcohol over an alternative reward is largely preserved, though it might be reduced compared to light, non-problem drinkers. Modulation of the insula cortex with TMS was not successful in decreasing alcohol use in individuals with alcohol addiction.
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| 8. |
- Kroll, Sara, et al.
(författare)
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Negative self-evaluation induced by acute stress indexed using facial EMG
- 2021
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Ingår i: Psychoneuroendocrinology. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0306-4530 .- 1873-3360. ; 133
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Tidskriftsartikel (refereegranskat)abstract
- Maladaptive stress responses are a key feature of several psychiatric disorders, but findings of stress effects on social behavior are inconsistent. Using a within-subject design, we investigated, in 35 healthy participants, the effects of acute stress on psychophysiological and behavioral responses during a simulated online social interaction task. Participants were exposed to established stress and non-stress exposure procedures in two separate sessions. During the task, participants liked or disliked pictures of other putative players and, similarly, saw their own picture being judged by others. After stress exposure, corrugator muscle activity (frowning) was significantly increased when participants saw their own picture while anticipating feedback from others. Consistently, zygomatic muscle activity (smiling) for self-evaluation was lower after stress than in the non-stress session. We found self-report of stress to be a significant predictor of corrugator activity in both sessions, indicating that higher levels of subjective stress overall were accompanied by increased negative self-evaluation. Surprisingly, no stress effects were found on behavioral measures of other-evaluation (i.e., percentage of dislikes to others), but corrugator response significantly predicted the percentage of dislikes during the stress session only. Overall, our findings suggest that stress increases negative self-evaluation as indexed by elevated corrugator activity. Furthermore, stress might sharpen the consistency between corrugator activity and negative evaluation of others. Our results indicate that negative self-evaluation might be a useful therapeutic target in patients with stressrelated psychiatric disorders. In this context, facial muscle activity may be an adequate biomarker for identifying stress-related differences in self-evaluation.
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| 9. |
- Löfberg, Andreas, 1987-, et al.
(författare)
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Assessing Childhood Maltreatment Exposure in Patients Without and With a Diagnosis of Substance Use Disorder
- 2023
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Ingår i: Journal of addiction medicine. - : Wolters Kluwer. - 1932-0620 .- 1935-3227. ; 17:3, s. 263-270
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Childhood maltreatment (CM), widely held as a risk factor for substance use disorders (SUDs), is commonly assessed using the Childhood Trauma Questionnaire (CTQ). Retrospective self-reports are, however, potentially subject to bias. We used a unique patient sample with prospectively documented CM to examine the performance of the CTQ and how this is affected by the presence of SUD.Methods: Analysis was based on a total of 104 individuals. Subjects with prospectively recorded CM were identified from a specialized childhood trauma unit in Linköping, Sweden (n = 55; 31 with SUD, 61% females; 24 without SUD, 71% females). Clinical controls had SUD but no CM (n = 25, 48% females). Healthy controls had neither SUD nor CM (n = 24, 54% females). We analyzed the agreement between retrospective CTQ scores and prospectively documented CM by κ analysis and assessed the performance of the CTQ to identify CM exposure using receiver operating characteristic (ROC) analysis.Results: Agreement between prospectively and retrospectively recorded CM exposure was poor for sexual abuse (36.6%, Cohen κ = 0.32, P = 0.008) and physical abuse (67.3%, κ = 0.35, P = 0.007). Overall CTQ performance was fair (ROC: area under the ROC curve = 0.78, optimal cutoff = 36.5, sensitivity = 0.65, specificity = 0.75). However, performance was excellent in the absence of SUD (area under the ROC curve = 0.93, cutoff = 32.0, sensitivity = 0.88, specificity = 0.88), but poor in participants with lifetime SUD (area under the ROC curve = 0.62, cutoff = 42.0, sensitivity = 0.60, specificity = 0.36).Conclusions: These data support the CTQ as a tool to assess CM exposure but suggest that it may be less useful in patients with SUD.
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| 10. |
- Mayo, Leah, et al.
(författare)
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Psychophysiological and Neural Support for Enhanced Emotional Reactivity in Female Adolescents With Nonsuicidal Self-injury
- 2021
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Ingår i: Biological Psychiatry. - : Elsevier. - 2451-9022. ; 6:7, s. 682-691
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Nonsuicidal self-injury (NSSI) is prevalent in adolescent populations worldwide. Emotion dysregulation is believed to contribute to NSSI, but underlying mechanisms are less known. We combined psychophysiological and neural data with subjective self-report in close temporal proximity to examine the mechanisms underlying emotion processing in adolescents with NSSI relative to control adolescents without a psychiatric diagnosis. METHODS: Thirty female adolescents with NSSI and 30 age-matched female control subjects were included in this case-control study. Participants were presented with negative affective pictures during a functional magnetic resonance imaging scan. In a separate facial electromyography session, the same participants were shown positive and negative affective images and also provided ratings of valence and arousal. RESULTS: Participants with NSSI responded to affective images with greater positive (e.g., zygomatic) and greater negative (e.g., corrugator) reactivity. We found no differences in self-reported affect in response to the images. Analyses of the negative picture-viewing functional magnetic resonance imaging data showed a significant positive correlation between anterior insula response and the averaged electromyography magnitude in NSSI, but not in control subjects. CONCLUSIONS: Adolescents with NSSI show enhanced emotional reactivity that is associated with anterior insula responding, but no abnormalities in self-reported affect. This discrepancy between self-report and objective measures of emotional reactivity potentially indicates a suppression of the emotional reaction in adolescents with NSSI. Moreover, the current data suggest potential targets for novel therapeutic approaches that can be combined with existing clinical treatment, such as real-time electromyography-based biofeedback focusing on emotional awareness, labeling, and expressing emotional experiences.
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