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- Richter, Hans O., et al.
(författare)
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Corrigendum: Prefrontal Cortex Oxygenation Evoked by Convergence Load Under Conflicting Stimulus-to-Accommodation and Stimulus-to-Vergence Eye-Movements Measured by NIRS
- 2018
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Ingår i: Frontiers in Human Neuroscience. - : Frontiers Media S.A.. - 1662-5161. ; 12
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- A Corrigendum onPrefrontal Cortex Oxygenation Evoked by Convergence Load Under Conflicting Stimulus-to-Accommodation and Stimulus-to-Vergence Eye-Movements Measured by NIRSby Richter, H. O., Forsman, M., Elcadi, G. H., Brautaset, R., Marsh, J. E., and Zetterberg, C. (2018). Front. Hum. Neurosci. 12:298. doi: 10.3389/fnhum.2018.00298In the original article, there was a mistake in Figure 5A (left panel) as published.Figure 5A (left panel) should show Ctrl Low convergence group, not Conv Low convergence group. The corrected Figure 5A (left panel) appears below. The authors apologize for this error and state that this does not change the scientific conclusions of the article in any way.The original article has been updated.
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| 2. |
- Richter, Hans O., et al.
(författare)
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Prefrontal Cortex Oxygenation Evoked by Convergence Load Under Conflicting Stimulus-to-Accommodation and Stimulus-to-Vergence Eye-Movements Measured by NIRS
- 2018
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Ingår i: Frontiers in Human Neuroscience. - : Frontiers Media SA. - 1662-5161. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To extend our knowledge of the functional linkages between visual fatigue and regional cerebral prefrontal cortex (PFC) oxygenation, we measured time related hemodynamic changes over the right dorsolateral prefrontal cortex (dlPFC) during convergence load under conflicting stimulus-to-accommodation and stimulus-to-vergence eye movements with and without concurrent mental load.Methods: Twenty healthy participants with a median age of 28 years (range: 18–44 years) fixated upon a vertical bar presented separately to the left and right eyes, using polarized filters, during four counterbalanced 10-min periods: (i) no accommodation/vergence conflict (Control, Ctrl); (ii) added convergence load and accommodation/vergence conflict (Conv); (iii) added cognitive load only (Cog) and; (iv) a combination of added cognitive and convergence load and accommodation/vergence conflict (Cc). Viewing distance was 65 cm. Non-invasive measurements of hemodynamic activity over the dlPFC were quantified by functional near-infrared spectroscopy (fNIRS). During the two-convergence load conditions, the horizontal disparity of the two bars varied dynamically from no disparity to a disparity set 20% below the individual threshold for diplopia. Cognitive load was induced by the n-back-2 test which required the subject to memorize and recall the changing colors of the horizontal bars and decide when a given color was the same as that occurring two colors previously. fNIRS data were averaged over 10-s windows centered at 0, 2, 4, 6, 8, and 10 min of each task, subtracted from a 20-s baseline window immediately preceding the visual task, and then represented as changes in oxygenated hemoglobin (ΔHbO2), deoxygenated hemoglobin (ΔHHb) and total hemoglobin (ΔtHb).Results: Linear mixed model analyses showed that hemodynamic activity was systematically influenced by time (p < 0.001). The group-averaged time-related level of change across the viewing conditions did not differ when compared with one another (p > 0.05). Larger convergence eye-movement responses under conflicting stimulus-to-accommodation, and stimulus-to-vergence over time, increased ΔHbO2 and ΔtHb only in condition Cc and after 8 min of task time (p < 0.10 for min-6 and min-8: p < 0.05 for min-10).Discussion: Collectively, our data suggest that HbO2, HHb, and tHb, recorded over the dlPFC with fNIRS, can be used to assay the degree to which supervisory oculomotor control processes are activated during visually deficient near work.
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| 3. |
- Sandberg, Camilla, et al.
(författare)
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Adults with congenital heart disease have impaired calf muscle oxygenation compared to control subjects
- 2019
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Ingår i: European Heart Journal. - : Oxford University Press. - 0195-668X .- 1522-9645. ; 40:Supplement_1
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundPeripheral muscle factors are presumed to be important contributors to the reduced exercise capacity in congenital heart disease (CHD), but the mechanisms are poorly understood.PurposeTo investigate if muscle oxygenation in the calf muscle is impaired in adults with complex CHD in comparison to controls.MethodSeventy-four adults with complex CHD (35.6±14.3 years, females n=22) were recruited from centers specialized in adult CHD. Seventy-four age and gender matched subjects were recruited as controls. Muscle oxygenation was successfully determined using near-infrared spectroscopy on the medial portion of m. gastrocnemiusin 63 patients and 67 controls. Measurements were made at rest, during venous occlusion to estimate blood flow (BF – indicated by the slope increase of total haemoglobin, HbT), at the start of isotonic unilateral heel-lifts to exhaustion, and immediately after exercise.ResultsIn comparison to controls, patients had a lower muscle saturation (StO2) at rest, albeit not statistically significant, (66±17% vs. 60±19%, p=0.07), and a lower BF (0.38±0.21 vs. 0.31±0.21 HbTx3.5sec–1, p=0.07). For exercise, compared to the controls, patients had a slower desaturation rate at exercise onset (−11.7±5.8% vs. −7.7±4.3%. StO2x3.5sec–1, p<0.001), and both a slower resaturation rate (6.1±3.8% vs. 3.9±3.7% StO2x3.5sec–1, p=0.002) and a slower half recovery time (16.8±11.1 vs. 28.6±21.2 sec, p<0.001) post exercise.ConclusionThe lower muscle oxygenation and blood flow at rest, and the slower oxygenation kinetics during exercise may give insight to the mechanism for the reduced exercise capacity commonly found in adults with complex CHD. This finding may also provide implications for design of rehabilitation programs for these patients.
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