Articles: learning-physiology.
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Primary ("early") sensory cortices have been viewed as stimulus analyzers devoid of function in learning, memory, and cognition. However, studies combining sensory neurophysiology and learning protocols have revealed that associative learning systematically modifies the encoding of stimulus dimensions in the primary auditory cortex (A1) to accentuate behaviorally important sounds. This "representational plasticity" (RP) is manifest at different levels. ⋯ Pairing tone with stimulation of the cholinergic nucleus basalis induces RP and implants specific behavioral memory, while directly increasing the representational area of a tone in A1 produces matching behavioral memory. Thus, RP satisfies key criteria for serving as a substrate of auditory memory. The findings suggest a basis for posttraumatic stress disorder in abnormally augmented cortical representations and emphasize the need for a new model of the cerebral cortex.
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Plasticity constitutes the basis of behavioral changes as a result of experience. It refers to neural network shaping and re-shaping at the global level and to synaptic contacts remodeling at the local level, either during learning or memory encoding, or as a result of acute or chronic pathological conditions. 'Plastic' brain reorganization after central nervous system lesions has a pivotal role in the recovery and rehabilitation of sensory and motor dysfunction, but can also be "maladaptive". Moreover, it is clear that brain reorganization is not a "static" phenomenon but rather a very dynamic process. ⋯ We will briefly discuss these dependencies, trying to highlight their translational value. Overall, it is not only necessary to better understand how the brain can reorganize after injury with or without therapy, it is also necessary to clarify when and why brain reorganization can be either "good" or "bad" in terms of its clinical consequences. This information is critical in order to develop and optimize cost-effective therapies to maximize functional recovery while minimizing maladaptive states after spinal cord injury.
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The last couple of decades have seen the development of a number of non-invasive brain stimulation (NIBS) techniques that are capable of inducing short-lasting plasticity in the human cortex. Importantly, the induction of lasting plastic changes can, under some conditions, reversibly modify behaviour and interact with learning. ⋯ We then outline the areas in which these techniques might be useful, namely, investigating the mechanisms of human cortical plasticity, the characterisation of influences on plasticity, and the investigation of the role of cortical regions in behaviour. Finally, we conclude by highlighting some current limitations of the techniques and suggest that further development of the current NIBS paradigms and more focussed targeting should further enhance the utility of these powerful non-invasive techniques for the investigation of the cortical plasticity and pathophysiology.
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Observational learning is the process used to explain the acquisition of novel behaviors or performance of previously acquired behaviors under novel conditions after observing the behavior of another person and the consequences that follow the behavior. Many learners with autism do not attend to environmental stimuli at a level sufficient to learn a range of prosocial behaviors through observation of others. Modeling, group or dyadic instruction, and explicit observation training can improve the extent to which individuals with autism learn through observation. This article reviews previous research that involved observational learning by individuals with autism and outlines future research that could benefit instructional practices.
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Deep brain stimulation (DBS) has emerged as a powerful technique to treat a host of neurological and neuropsychiatric disorders from Parkinson's disease and dystonia, to depression, and obsessive compulsive disorder (Benabid et al., 1987; Lang and Lozano, 1998; Davis et al., 1997; Vidailhet et al., 2005; Mayberg et al., 2005; Nuttin et al., 1999). More recently, results suggest that DBS can enhance memory for facts and events that are dependent on the medial temporal lobe (MTL), thus raising the possibility for DBS to be used as a treatment for MTL- related neurological disorders (e.g. ⋯ We also discuss current knowledge regarding the temporal specificity, underlying neurophysiological mechanisms of action, and generalization of stimulation's effects on memory. Throughout our discussion, we also propose several future directions that will provide the necessary insight into if and how DBS could be used as a therapeutic treatment for memory disorders.