Mechanisms underlying the control and generalization of sensorimotor learning

点击翻译按钮获取中文摘要

To cope with a continuously changing environment, the human brain has evolved an impressive ability to flexibly adjust, from one movement to the next, its motor commands. Such learning is a hallmark of any intelligent system and is central to human cognition and behaviour. Yet, the mechanisms that support sensorimotor learning and updating, and which allow acquired skills to be readily transferred to new contexts, remains poorly understood. The broad aims of the research program proposed here are to (1) better understand the mechanisms and strategies through which individuals learn sensorimotor tasks, (2) explore how this learning can be improved and better generalized, and (3) better understand the neural circuitry that supports sensorimotor learning and updating. The proposed research consists of three separate projects.Project 1:An important feature of the success of many well-learned skills is that they generalize to new contexts. Yet, the ways in which such generalization might be maximized has received very little attention and has important practical benefits for workplace, musical and sports training. PROJECT 1, by manipulating participant sensory feedback, will determine how skills acquired with one hand can be best generalized to the other, untrained hand. In addition, using neurostimulation tools, we will assess the causal neural mechanisms underlying this generalization.Project 2:Society often takes the view that, whereas the forgetting or loss of information is to be prevented and remedied, the retention of information is to be practised and improved. While this may be true of many of our declarative memories (e.g., remembering family members, facts, figures, etc.), it is critical that our motor systems have the capacity to suppress certain types of learning that can interfere with overall task performance. PROJECT 2 will test the hypothesis that the motor system, in situations in which the interference effects associated with learning two separate tasks overrides the gains associated with learning each of those tasks, will intelligently suppress learning the less valued task. Project 3:Motor learning is often examined using adaptation tasks in which individuals are required to respond to unusual forces or changes in visual feedback. However, significant learning also occurs in standard everyday tasks, as when acquiring the weight of an object lifted for the first time. We recently showed that object weight information, gained through lifting, is represented in the ventral visual pathway. However, the causal role of this representation in object motor interactions remains unclear. PROJECT 3 will use functional MRI and neurostimulation tools to causally assess the role of the ventral visual pathway in weight encoding and determine how perturbing the activity of ventral visual areas disrupts the activity of interconnected regions in frontoparietal cortex.