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- Boraxbekk, Carl-Johan, 1980-, et al.
(författare)
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Motor and mental training in older people : Transfer, interference, and associated functional neural responses
- 2016
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Ingår i: Neuropsychologia. - : Elsevier BV. - 0028-3932 .- 1873-3514. ; 89, s. 371-377
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Tidskriftsartikel (refereegranskat)abstract
- Learning new motor skills may become more difficult with advanced age. In the present study, we randomized 56 older individuals, including 30 women (mean age 70.6 years), to 6 weeks of motor training, mental (motor imagery) training, or a combination of motor and mental training of a finger tapping sequence. Performance improvements and post-training functional magnetic resonance imaging (fMRI) were used to investigate performance gains and associated underlying neural processes. Motor only training and a combination of motor and mental training improved performance in the trained task more than mental-only training. The fMRI data showed that motor training was associated with a representation in the premotor cortex and mental training with a representation in the secondary visual cortex. Combining motor and mental training resulted in both premotor and visual cortex representations. During fMRI scanning, reduced performance was observed in the combined motor and mental training group, possibly indicating interference between the two training methods. We concluded that motor and motor imagery training in older individuals is associated with different functional brain responses. Furthermore, adding mental training to motor training did not result in additional performance gains compared to motor-only training and combining training methods may result in interference between representations, reducing performance.
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| 2. |
- Boraxbekk, Carl-Johan, 1980-, et al.
(författare)
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Physical activity over a decade modifies age-related decline in perfusion, gray matter volume, and functional connectivity of the posterior default mode network : a multimodal approach
- 2016
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Ingår i: NeuroImage. - : Elsevier. - 1053-8119 .- 1095-9572. ; 131, s. 133-141
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Tidskriftsartikel (refereegranskat)abstract
- One step toward healthy brain aging may be to entertain a physically active lifestyle. Studies investigating physical activity effects on brain integrity have, however, mainly been based on single brain markers, and few used a multimodal imaging approach. In the present study, we used cohort data from the Betula study to examine the relationships between scores reflecting current and accumulated physical activity and brain health. More specifically, we first examined if physical activity scores modulated negative effects of age on seven resting state networks previously identified by Salami, Pudas, and Nyberg (2014). The results revealed that one of the most age-sensitive RSN was positively altered by physical activity, namely, the posterior default-mode network involving the posterior cingulate cortex (PCC). Second, within this physical activity-sensitive RSN, we further analyzed the association between physical activity and gray matter (GM) volumes, white matter integrity, and cerebral perfusion using linear regression models. Regions within the identified DMN displayed larger GM volumes and stronger perfusion in relation to both current and 10-years accumulated scores of physical activity. No associations of physical activity and white matter integrity were observed. Collectively, our findings demonstrate strengthened PCC–cortical connectivity within the DMN, larger PCC GM volume, and higher PCC perfusion as a function of physical activity. In turn, these findings may provide insights into the mechanisms of how long-term regular exercise can contribute to healthy brain aging.
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| 3. |
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| 4. |
- Månsson, Kristoffer N T, et al.
(författare)
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Neuroplasticity in response to cognitive behavior therapy for social anxiety disorder
- 2016
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Ingår i: Translational Psychiatry. - : Springer Science and Business Media LLC. - 2158-3188. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Patients with anxiety disorders exhibit excessive neural reactivity in the amygdala, which can be normalized by effective treatment like cognitive behavior therapy (CBT). Mechanisms underlying the brain’s adaptation to anxiolytic treatments are likely related both to structural plasticity and functional response alterations, but multimodal neuroimaging studies addressing structure–function interactions are currently missing. Here, we examined treatment-related changes in brain structure (gray matter (GM) volume) and function (blood–oxygen level dependent, BOLD response to self-referential criticism) in 26 participants with social anxiety disorder randomly assigned either to CBT or an attention bias modification control treatment. Also, 26 matched healthy controls were included. Significant time × treatment interactions were found in the amygdala with decreases both in GM volume (family-wise error (FWE) corrected PFWE=0.02) and BOLD responsivity (PFWE=0.01) after successful CBT. Before treatment, amygdala GM volume correlated positively with anticipatory speech anxiety (PFWE=0.04), and CBT-induced reduction of amygdala GM volume (pre–post) correlated positively with reduced anticipatory anxiety after treatment (PFWE0.05). In addition, we observed greater amygdala neural responsivity to self-referential criticism in socially anxious participants, as compared with controls (PFWE=0.029), before but not after CBT. Further analysis indicated that diminished amygdala GM volume mediated the relationship between decreased neural responsivity and reduced social anxiety after treatment (P=0.007). Thus, our results suggest that improvement-related structural plasticity impacts neural responsiveness within the amygdala, which could be essential for achieving anxiety reduction with CBT.
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| 5. |
- Stomby, Andreas, et al.
(författare)
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Higher diurnal salivary cortisol levels are related to smaller prefrontal cortex surface area in elderly men and women
- 2016
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Ingår i: European Journal of Endocrinology. - 0804-4643 .- 1479-683X. ; 175:2, s. 117-126
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Elevated cortisol levels with aging have been associated with atrophy of the hippocampus and prefrontal cortex (PFC), as well as with impaired cognitive functions in men. However, coexisting diseases have confounded many studies examining these relationships. Studies in women are lacking. Our objective was to test whether salivary cortisol levels were related to morphology of the hippocampus and the PFC, and to cognitive performance.Design: A cross-sectional study including 200 elderly (55-80 years old) men and women.Method: We used magnetic resonance imaging, tests of episodic-, semantic-, and working memory, visuospatial ability, and cortisol levels in four saliva samples collected during 1 day.Results: Area under the curve (AUC) for cortisol levels was negatively related to cortical surface area of the left anterior cingulate gyrus (caudal P < 0.001; rostral P = 0.006), right lateral orbitofrontal cortex (P = 0.004), and right rostral middle frontal gyrus (P = 0.003). In women, there was also a negative relationship with cortical surface area in the left rostral middle frontal gyrus (P = 0.006). No relationship was found between cortisol levels and hippocampal volume.Conclusion: This study suggests that the structure of the medial PFC is related to cortisol levels in both elderly women and men.
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| 6. |
- Wennberg, Patrik, et al.
(författare)
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Acute effects of breaking up prolonged sitting on fatigue and cognition : a pilot study
- 2016
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Ingår i: BMJ Open. - : BMJ. - 2044-6055. ; 6:2
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To compare the acute effects of uninterrupted sitting with sitting interrupted by brief bouts of light-intensity walking on self-reported fatigue, cognition, neuroendocrine biomarkers and cardiometabolic risk markers in overweight/obese adults.Design: Randomised two-condition crossover trial.Setting: Laboratory study conducted in Melbourne, Australia.Participants: 19 overweight/obese adults (45–75 years).Interventions: After an initial 2 h period seated, participants consumed a meal-replacement beverage and completed (on 2 days separated by a 6-day washout period) each condition over the next 5 h: uninterrupted sitting (sedentary condition) or sitting with 3 min bouts of light-intensity walking every 30 min (active condition).Primary outcome measures: Self-reported fatigue, executive function and episodic memory at 0 h, 4 h and 7 h.Secondary outcome measures: Neuroendocrine biomarkers and cardiometabolic risk markers (blood collections at 0 h, 4 h and 7 h, blood pressure and heart rate measured hourly and interstitial glucose measured using a continuous glucose monitoring system).Results: During the active condition, fatigue levels were lower at 4 h (−13.32 (95% CI −23.48 to −3.16)) and at 7 h (−10.73 (95% CI −20.89 to −0.58)) compared to the sedentary condition. Heart rate was higher at 4 h (4.47 (95% CI 8.37 to 0.58)) and at 7 h (4.32 (95% CI 8.21 to 0.42)) during the active condition compared to the sedentary condition. There were no significant differences between conditions by time for other variables. In the sedentary condition, changes in fatigue scores over time correlated with a decrease in heart rate and plasma dihydroxyphenylalanine (DOPA) and an increase in plasma dihydroxyphenylglycol (DHPG).Conclusions: Interrupting prolonged sitting with light-intensity walking breaks may be an effective fatigue countermeasure acutely. Fatigue levels corresponded with the heart rate and neuroendocrine biomarker changes in uninterrupted sitting in this pilot study. Further research is needed to identify potential implications, particularly for the occupational health context.
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