Research On The Temporal-spatial Continuity And Plasticity Of Cognitive Processing Of Human Brain

Recently, there are significantly increased studies of cognitive neuroscience. However, few directly addresses the basic theoretical question. In this dissertation, we systematically investigated temporal and spatial patterns of cognitive processing under the backgrounds of two main cognitive processing theories, symbolism and connectionism.Study 1 showed that the stages of cognitive processing have a continuous temporal pattern by employing the choice go/no-go paradigm and lateralized readiness potentials. Study 1 therefore supported the connectionism theory which posited different processing stages could overlap in time. And it rejected a discrete pattern proposed by the symbolism theory that the later processing stage starts only after the completion of the former stage. Using the same paradigm with study 1, study 2 set two experimental conditions to investigate whether the perceptional discriminability or the category identity of a stimulus supported a continuous temporal pattern of cognitive processing. The results showed the perceptional discriminability played a key role for a continuous temporal pattern instead of the category identity. Using an auditory learning task combined with electrophysiological recordings, study 3 revealed for the first time that cognitive plasticity during learning transformed the continuous temporal pattern into the discrete temporal pattern to achieve the rapid, error-free performance. The study also presented a new model showing how the brain may resolve its cognitive processing dilemma.Research has shown that distinct insular subregions are associated with particular neural networks(e.g., attentional and sensorimotor networks). Based on the evidence that playing action video games(AVGs) facilitates attentional and sensorimotor functions, this study examined the relation between AVG experience and the plasticity of insular subregions and the functional networks therein that are related to attentional and sensorimotor functions. By comparing AVG experts and amateurs, Study 4 found that AVG experts had enhanced functional connectivity and grey matter volume in insular subregions. Thus, the study 4 revealed a continuous spatial pattern is related to AVG playing which may enhance functional integration of insular subregions and the pertinent networks therein. Study 5 investigated whether habitual AVG playing could enhance the integration between Salience Network and Central Executive Network to support better performance of attention and working memory. By comparing AVG experts and amateurs with resting-state functional connectivity as well as graph theoretical analysis, it turned out that AVG experts had enhanced functional integration both within and between SN and CEN as compared to the amateurs. This study therefore revealed a continuous spatial pattern at the neural network level, which involved AVG playing cognitive benefits on attention and working memory.To examine whether AVG playing could induce brain plasticity of the continuous spatial pattern, Study 6 conducted a longitudinal study where participants were randomly assigned to either the training or the active control group. Both groups received video game training for one year with various confounding variables controlled(e.g., expectation effects, active controls, and prior experience). Compared with active controls, participants in the AVG training group had enhanced functional connectivity density and increased gray matter volume in the prefrontal lobe, precentral gyrus, postcentral gyrus, insula, and other brain regions. Furthermore, in the training group, the amount of brain change correlated with training frequency. Thus, to the best of our knowledge, this is the first longitudinal study to show that AVG playing can influence the spatial continuous pattern of cognitive processing when various critical confounding variables are controlled.In summary, based on our six experimental studies, this dissertation showed that there is a continuity in the both temporal and spatial patterns of cognitive processing; and, this continuity of temporal and spatial patterns can be influenced by learning experience. A continuous pattern could involve both top-down and bottom-up processing which allows a trade off strategy of speed and accuracy. A discrete pattern could only involve the bottom-up processing which allows an accuracy strategy. Study 3 and 6 have demonstrated that learning activities could influence both temporal and spatial patterns of cognitive processing, like changing a trade off strategy of speed and accuracy or an accuracy strategy into a speed and accuracy simultaneously. This dissertation therefore suggests the relationship between a continuous and a discrete pattern is a dialectical unity, not merely an opposing one.