| 1. |
- Bergman, Frida, 1984-
(författare)
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Active workstations : a NEAT way to prevent and treat overweight and obesity?
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Modern society is triggering sedentary behaviours in different domains. Different strategies can be used to reduce the time spent sitting and increase physical activity in the office environment, which is one domain where sedentary time is often high. One such strategy could be to install treadmill workstations. With these, the office workers can walk on a treadmill while performing their usual work tasks at the computer. However, the long-term effects of these workstations are not known. Aim: The overall aim of this thesis was to investigate the long-term effects on sedentary behaviour, physical activity and associated health factors of installing treadmill workstations in offices compared to regular office work.Method: In this randomized controlled trial, 80 sedentary, middle-aged, healthy office workers with overweight or obesity were individually randomized into either an intervention or a control group. Those in the intervention group had a treadmill workstation installed at their sit-stand desk, to use for at least one hour per day for 13 months. They further received boosting e-mails at four time-points during the study. Participants in the control group continued to work as normal at their sit-stand office desk. All participants also received a health consultation at the beginning of the study, where they got to discuss physical activity and diet recommendations. Measurements reported include physical activity and sedentary behaviour, anthropometric measurements, body composition, metabolic outcomes, stress, depression and anxiety, cognitive function, structural brain images and interview data. Linear mixed models were used for the main statistical analyses of the quantitative data. An exploratory approach was also undertaken, using orthogonal partial least squares regression on the baseline data. Finally, interview data from participants in the intervention group were analysed using a modified Grounded Theory approach.Results: The intervention group increased their daily walking time and their number of steps at all follow-ups compared to the control group. Concomitantly, a decrease in moderate-to-vigorous intensity physical activity (MVPA) was observed within both groups, mainly during weekends. No intervention effects were observed on any of the body, cognitive or brain volume measurements. Our exploratory analyses revealed a significant association between smaller hippocampal volume and percentage sitting time among participants over 51 years of age. From the interview data, we discovered a core category, “The Capacity to Benefit”. The categories were described as the ideal types the Convinced, the Competitive, the Responsible and the Vacillating, based on the principal characteristics of the participants representing their different motivational status and strategies to reach the goal of benefitting from the intervention. Conclusion: It is possible to increase daily physical activity in office environments by introducing treadmill workstations. Future interventions should adapt strategies for the individuals based on their motivational level, but should also workwith the social and physical environment and with factors within the organization to gain the best effects of these interventions.
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| 2. |
- Malmberg Gavelin, Hanna, 1982-
(författare)
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Rehabilitation for improved cognition in stress-related exhaustion : cognitive, neural and clinical perspectives
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Stress-related exhaustion disorder (ED) has been associated with concomitant cognitive impairment, perceived by patients to have large impact on everyday life. However, little is known about how to address cognition in stress rehabilitation and how this could influence stress recovery over time. The aim of this thesis was to evaluate the efficacy of additional cognitive and aerobic training for patients with ED who participated in a multimodal stress rehabilitation program. A further aim was to explore the neural correlates of ED. The main focus of this thesis was on cognitive training, the effects of which were studied from a cognitive, neural, and clinical perspective (Study I-III). The final part of this thesis (Study III) broadened the perspective and investigated the long-term effects of cognitive and aerobic training on cognitive and clinical outcomes.Study I and II evaluated the effects of process-based cognitive training immediately following the intervention. The results from Study I showed that generalization of training effects following cognitive training was selective and restricted to tasks similar to those trained. The cognitive training group showed a greater reduction in burnout symptoms, and partial support was given for fewer subjective cognitive complaints compared to stress rehabilitation alone. Study II used functional neuroimaging to explore the neural effects of cognitive training, showing training-related activation increases at high working memory load; however, conclusions were restricted due to the small sample.Study II additionally explored the neural correlates of ED by investigating within-group associations between burnout level and functional neural response during working memory updating. The results revealed that patients with higher levels of burnout showed greater recruitment of working memory-related regions during task execution, potentially reflecting a compensatory mechanism serving to uphold task performance.Study III evaluated the clinical utility of addressing cognitive impairments in stress rehabilitation. Here, the effects of cognitive and aerobic training on several ED-related variables were investigated 1 year after the intervention. Cognitive training was associated with a small and lasting improvement in cognitive performance. Aerobic training yielded improvements in episodic memory immediately following the intervention, but no significant difference was found between the aerobic training group and the control group at 1-year follow-up. For psychological health and work ability, no additional benefits were seen for the added interventions relative to stress rehabilitation alone. However, a long-term improvement in burnout symptoms favouring cognitive training was observed when restricting the analysis to only include patients who had completed the intervention. This highlights the importance of supporting patients in adhering to added treatments.In sum, the papers in this thesis provide initial evidence of neurocognitive plasticity in patients with ED and tentatively suggest that cognitive improvements following cognitive training may translate into alleviated clinical symptoms. These results support the argument that interventions targeting cognitive impairments holds a place in the effective rehabilitation of ED.
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| 3. |
- Johansson, Anna-Maria, 1981-, et al.
(författare)
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Influence of visual feedback, hand dominance and sex on individuated finger movements
- 2021
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Ingår i: Experimental Brain Research. - : Springer. - 0014-4819 .- 1432-1106. ; 239:6, s. 1911-1928
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Tidskriftsartikel (refereegranskat)abstract
- The ability to perform individual finger movements, highly important in daily activities, involves visual monitoring and proprioception. We investigated the influence of vision on the spatial and temporal control of independent finger movements, for the dominant and non-dominant hand and in relation to sex. Twenty-six healthy middle-aged to old adults (M age = 61 years; range 46–79 years; females n = 13) participated. Participants performed cyclic flexion–extension movements at the metacarpophalangeal joint of one finger at a time while keeping the other fingers as still as possible. Movements were recorded using 3D optoelectronic motion technique (120 Hz). The movement trajectory distance; speed peaks (movement smoothness); Individuation Index (II; the degree a finger can move in isolation from the other fingers) and Stationarity Index (SI; how still a finger remains while the other fingers move) were extracted. The main findings were: (1) vision only improved the II and SI marginally; (2) longer trajectories were evident in the no-vision condition for the fingers of the dominant hand in the female group; (3) longer trajectories were specifically evident for the middle and ring fingers within the female group; (4) females had marginally higher II and SI compared with males; and (5) females had fewer speed peaks than males, particularly for the ring finger. Our results suggest that visual monitoring of finger movements marginally improves performance of our non-manipulative finger movement task. A consistent finding was that females showed greater independent finger control compared with males.
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| 4. |
- Strong, Andrew, et al.
(författare)
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Brain Response to a Knee Proprioception Task Among Persons With Anterior Cruciate Ligament Reconstruction and Controls
- 2022
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Ingår i: Frontiers in Human Neuroscience. - : Frontiers Media S.A.. - 1662-5161. ; 16
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Tidskriftsartikel (refereegranskat)abstract
- Knee proprioception deficits and neuroplasticity have been indicated following injury to the anterior cruciate ligament (ACL). Evidence is, however, scarce regarding brain response to knee proprioception tasks and the impact of ACL injury. This study aimed to identify brain regions associated with the proprioceptive sense of joint position at the knee and whether the related brain response of individuals with ACL reconstruction differed from that of asymptomatic controls. Twenty-one persons with unilateral ACL reconstruction (mean 23 months post-surgery) of either the right (n = 10) or left (n = 11) knee, as well as 19 controls (CTRL) matched for sex, age, height, weight and current activity level, performed a knee joint position sense (JPS) test during simultaneous functional magnetic resonance imaging (fMRI). Integrated motion capture provided real-time knee kinematics to activate test instructions, as well as accurate knee angles for JPS outcomes. Recruited brain regions during knee angle reproduction included somatosensory cortices, prefrontal cortex and insula. Neither brain response nor JPS errors differed between groups, but across groups significant correlations revealed that greater errors were associated with greater ipsilateral response in the anterior cingulate (r = 0.476, P = 0.009), supramarginal gyrus (r = 0.395, P = 0.034) and insula (r = 0.474, P = 0.008). This is the first study to capture brain response using fMRI in relation to quantifiable knee JPS. Activated brain regions have previously been associated with sensorimotor processes, body schema and interoception. Our innovative paradigm can help to guide future research investigating brain response to lower limb proprioception.
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| 5. |
- Strong, Andrew, et al.
(författare)
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Right hemisphere brain lateralization for knee proprioception among right-limb dominant individuals
- 2023
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Ingår i: Frontiers in Human Neuroscience. - : Frontiers Media S.A.. - 1662-5161. ; 17
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Studies indicate that brain response during proprioceptive tasks predominates in the right hemisphere. A right hemisphere lateralization for proprioception may help to explain findings that right-limb dominant individuals perform position matching tasks better with the non-dominant left side. Evidence for proprioception-related brain response and side preference is, however, limited and based mainly on studies of the upper limbs. Establishing brain response associated with proprioceptive acuity for the lower limbs in asymptomatic individuals could be useful for understanding the influence of neurological pathologies on proprioception and locomotion.Methods: We assessed brain response during an active unilateral knee joint position sense (JPS) test for both legs of 19 right-limb dominant asymptomatic individuals (females/males = 12/7; mean ± SD age = 27.1 ± 4.6 years). Functional magnetic resonance imaging (fMRI) mapped brain response and simultaneous motion capture provided real-time instructions based on kinematics, accurate JPS errors and facilitated extraction of only relevant brain images.Results: Significantly greater absolute (but not constant nor variable) errors were seen for the dominant right knee (5.22° ± 2.02°) compared with the non-dominant left knee (4.39° ± 1.79°) (P = 0.02). When limbs were pooled for analysis, significantly greater responses were observed mainly in the right hemisphere for, e.g., the precentral gyrus and insula compared with a similar movement without position matching. Significant response was also observed in the left hemisphere for the inferior frontal gyrus pars triangularis. When limbs were assessed independently, common response was observed in the right precentral gyrus and superior frontal gyrus. For the right leg, additional response was found in the right middle frontal gyrus. For the left leg, additional response was observed in the right rolandic operculum. Significant positive correlations were found between mean JPS absolute errors for the right knee and simultaneous brain response in the right supramarginal gyrus (r = 0.464, P = 0.040).Discussion: Our findings support a general right brain hemisphere lateralization for proprioception (knee JPS) of the lower limbs regardless of which limb is active. Better proprioceptive acuity for the non-dominant left compared with the dominant right knee indicates that right hemisphere lateralization may have meaningful implications for motor control.
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| 6. |
- Farnsworth von Cederwald, Bryn, et al.
(författare)
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White matter lesion load determines exercise-induced dopaminergic plasticity and working memory gains in aging
- 2023
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Ingår i: Translational Psychiatry. - : Springer Nature. - 2158-3188. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- Age-related dopamine reductions have been suggested to contribute to maladaptive working memory (WM) function in older ages. One promising intervention approach is to increase physical activity, as this has been associated with plasticity of the striatal dopamine system and WM improvements, however with individual differences in efficacy. The present work focused on the impact of individual differences in white-matter lesion burden upon dopamine D2-like receptor (DRD2) availability and WM changes in response to a 6 months physical activity intervention. While the intervention altered striatal DRD2 availability and WM performance in individuals with no or only mild lesions (p < 0.05), no such effects were found in individuals with moderate-to-severe lesion severity (p > 0.05). Follow-up analyses revealed a similar pattern for processing speed, but not for episodic memory performance. Linear analyses further revealed that lesion volume (ml) at baseline was associated with reduced DRD2 availability (r = −0.41, p < 0.05), and level of DRD2 change (r = 0.40, p < 0.05). Taken together, this study underlines the necessity to consider cerebrovascular health in interventions with neurocognitive targets. Future work should assess whether these findings extend beyond measures of DRD2 availability and WM.
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| 7. |
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| 8. |
- Karalija, Nina, 1984-, et al.
(författare)
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High long-term test-retest reliability for extrastriatal C-11-raclopride binding in healthy older adults
- 2020
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Ingår i: Journal of Cerebral Blood Flow and Metabolism. - : Sage Publications. - 0271-678X .- 1559-7016. ; 40:9, s. 1859-1868
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Tidskriftsartikel (refereegranskat)abstract
- In vivo dopamine D2-receptor availability is frequently assessed with C-11-raclopride and positron emission tomography. Due to low signal-to-noise ratios for C-11-raclopride in areas with low D2 receptor densities, the ligand has been considered unreliable for measurements outside the dopamine-dense striatum. Intriguingly, recent studies show that extrastriatal C-11-raclopride binding potential (BPND) values are (i) reliably higher than in the cerebellum (where D2-receptor levels are negligible), (ii) correlate with behavior in the expected direction, and (iii) showed good test-retest reliability in a sample of younger adults. The present work demonstrates high seven-month test-retest reliability of striatal and extrastriatal C-11-raclopride BPND values in healthy, older adults (n = 27, age: 64-78 years). Mean C-11-raclopride BPND values were stable between test sessions in subcortical nuclei, and in frontal and temporal cortices (p > 0.05). Across all structures analyzed, intraclass correlation coefficients were high (0.85-0.96), absolute variability was low (mean: 4-8%), and coefficients of variance ranged between 9 and 25%. Furthermore, regional C-11-raclopride BPND values correlated with previously determined F-18-fallypride BPND values (rho = 0.97 and 0.92 in correlations with and without striatal values, respectively, p < 0.01) and postmortem determined D2-receptor densities (including striatum: rho = 0.92; p < 0.001; excluding striatum: rho = 0.75; p = 0.067). These observations suggest that extrastriatal C-11-raclopride measurements represent a true D2 signal.
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