| The brain,as the source of human behavior,is by design molded by environmental changes and pressures,physiologic modifications,and experiences.We strongly suggest that plasticity is an intrinsic property of the nervous system retained throughout a lifespan and that it is not possible to understand normal psychological function or the manifestations or consequences of disease without invoking the concept of brain plasticity.In recent years,with the emergence and maturation of magnetic resonance imaging(MRI),researchers have been able to conduct in vivo studies on changes in the plasticity of the brain and its mechanisms at the system level.Among all research subjects,experts have received much scientific attention,in that expertise represents the level par excellence for human learning.Several expertise models have been brought up by different research groups to study undetermined issue in the field of perceptual learning,motor learning and cognitive learning.A British group established the expertise model of London taxi driver to study hippocampus role in spatial navigation.German groups have proposed the model of professional musicians to study the perceptualmotor learning mechanism.And the model of meditators is introduced to study higher-order cognitive functions,such as attention direction and cognitive control.Visual recognition is the basic ability of mankind,is of great significance to survival,and has high social significance.Therefore,the study of neural mechanisms behind the human visual recognition ability has always been the focus of neuroscience research.Medical imaging has played a decisive role in predicting,diagnosing and treating the disease,and the imaging physician is inseparable from medical imaging and plays a decisive role in medical imaging.The visual recognition ability is the basis for radiologists.Therefore,with the help of magnetic resonance imaging technology,this paper focuses on the model of radiologists and used amplitude of low frequency fluctuation and voxel based morphometry to study the neural substrate of visual recognition expertise.The first study used amplitude of low-frequency fluctuations(ALFF)to detect the local functional changes,i.e.,the local baseline brain activity in the radiologists’ brain after shortterm training.The ALFF,which measures the total power of a given time course within a typical frequency range(e.g.,0.01–0.08 Hz),has been proven to be a valuable parameter to reflect the baseline brain activity.The results explicated higher ALFF in the right fusiform gyrus and the left orbitofrontal cortex(OFC)(corrected for multiple comparisons).Additionally,ALFF of fusiform gyrus correlated with the intern radiologists’ behavioral expertise(corrected for multiple comparisons).We suggest short-term visual training changed the baseline brain activity in both high-level visual cortex and high order cognitive cortex,indicating the engagement of both top-down and bottom-up facilitation.We provide a novel perspective by introducing the resting state changes.The second study used voxel based morphometry to detect the local grey matter changes in visual experts.Our results demonstrated that the grey matter volumes in the left primary visual cortex were significantly higher in the visual experts.But,the exact physiological nature behind this finding is quite complicated,including neuronal specific and non-specific factors.The following study should focus on this and further explicate this issue using more specific experimental design,as well as other imaging modalities.In conclusion,We suggest that our study may help elucidate a long-lasting question that how visual expertise develops.Also,we propose that our current study may add lines to develop new training protocol in medical school.In conclusion,our findings suggest that the radiological experience changes the brain baseline,which may represent the innate demand required in their daily practice. |
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