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Fig. 3 | Journal of Translational Medicine

Fig. 3

From: Brain mediators of systemic oxidative stress on perceptual impairments in Parkinson’s disease

Fig. 3

Middle temporal gyrus as potential brain mediator between oxidative stress level and different perceptual functions. Mediation path diagram showing the relationship between oxidative stress level (predictor, TBARS), regional gray matter volume (mediator, using MTG for visualization purpose, the other potential brain mediators and full statistics are presented in Table 3), and different perceptual functions (dependent variable, A DS; B BD; C POI; and D PIQ). The dark solid and light dashed lines indicate the significant/non-significant relationship between each variable, respectively. The hypothesized causalities are presented as one-directional arrows. The corresponding mean path coefficients with standard errors of the path a, path b, path c’, and mediation a*b effects for each mediation model are also labeled. The correlation scatterplots indicate the relationship between oxidative stress level, MTG gray matter volume, and different perceptual functions across whole study groups (“path a” and “path b” effects, respectively). The histogram shows the bootstrap estimates of mediation a*b effect distribution of MTG for each mediation model. The light gray shading shows the 95 % confidence intervals of bootstrap estimates and the vertical line indicates the null hypothesis value of zero. *p < 0.05, **p < 0.01, ***p < 0.001. BD block design, DS digit symbol, MTG middle temporal gyrus, PIQ performance intelligence quotient, POI perceptual organization index, TBARS thiobarbituric acid reactive substances

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