Sean Barton and Jason Ralph, Cognitive Science Graduate Students, RPI


Sean Barton and Jason Ralph, Cognitive Science Graduate Students, RPI

Sage 4101

October 1, 2014 12:00 PM - 1:30 PM

Jason Ralph:  The impact of task environments on cognitive strategies are well known and have formed the basis of many important findings in cognitive science.  However, these effects are often overlooked in research design. The n-back, thought to measure working memory and executive control capacity, is especially prone to misinterpretation because of a lack of standardization in how researchers administer the task.  I will report on a set of experiments demonstrating that experimental design variation along several dimensions can have large effects on the strategies people employ to perform the task.  The results highlight the importance of understanding the connection between strategy and the environment and have implications beyond the n-back task.  

Sean Barton:  During the production of a movement, the central nervous system (CNS) must organize components of the motor system around some desirable goal or outcome. A difficulty in this process is the reality that there are often more motor components than are strictly needed to satisfy the constraints of the task at hand. This excess of components creates redundancy in the movements and configuration of the motor system such that there exist multiple ways of realizing action goals. While redundancy is a source of computational complexity, it can also provide stability and flexibility in action. Studies have shown that the CNS can exploit redundancy to reduce variability in action goals by strategically co-varying the actions of redundant motor components. Such co-variation reduces error in the action goal by distributing variability across the set of redundant motor solutions that yield the same outcome. While this strategy has been demonstrated in a number of well-learned movements, this account critically assumes that redundant motor solutions are generally equitable. This contradicts findings that the comfort associated with particular configurations of the body are strong determiners of how an action is performed. In this talk I will discuss the competition between these perspectives and present a possible hypothesis for how these disparate findings might be synthesized.




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