Trewartha Kevin M, Flanagan J Randall
Centre for Neuroscience Studies, Queen's University, Kingston, Ontario K7L 3N6, Canada; Department of Psychology, Queen's University, Kingston, Ontario K7L 3N6, Canada; Department of Cognitive and Learning Sciences, Michigan Technological University, Houghton, MI 49931, USA; Department of Kinesiology and Integrative Physiology, Michigan Technological University, Houghton, MI 49931, USA.
Centre for Neuroscience Studies, Queen's University, Kingston, Ontario K7L 3N6, Canada; Department of Psychology, Queen's University, Kingston, Ontario K7L 3N6, Canada.
Cognition. 2017 Jun;163:121-127. doi: 10.1016/j.cognition.2017.02.014. Epub 2017 Mar 17.
Distinct explicit and implicit memory processes support weight predictions used when lifting objects and making perceptual judgments about weight, respectively. The first time that an object is encountered weight is predicted on the basis of learned associations, or priors, linking size and material to weight. A fundamental question is whether the brain maintains a single, global representation of priors, or multiple representations that can be updated in a context specific way. A second key question is whether the updating of priors, or the ability to scale lifting forces when repeatedly lifting unusually weighted objects requires focused attention. To investigate these questions we compared the adaptability of weight predictions used when lifting objects and judging their weights in different groups of participants who experienced size-weight inverted objects passively (with the objects placed on the hands) or actively (where participants lift the objects) under full or divided attention. To assess weight judgments we measured the size-weight illusion after every 20 trials of experience with the inverted objects both passively and actively. The attenuation of the illusion that arises when lifting inverted object was found to be context-specific such that the attenuation was larger when the mode of interaction with the inverted objects matched the method of assessment of the illusion. Dividing attention during interaction with the inverted objects had no effect on attenuation of the illusion, but did slow the rate at which lifting forces were scaled to the weight inverted objects. These findings suggest that the brain stores multiple representations of priors that are context specific, and that focused attention is important for scaling lifting forces, but not for updating weight predictions used when judging object weight.
不同的显性和隐性记忆过程分别支持在举起物体和对重量进行感知判断时所使用的重量预测。首次遇到一个物体时，重量是根据将大小和材质与重量联系起来的习得关联或先验知识来预测的。一个基本问题是，大脑是维持单一的、全局的先验知识表征，还是维持可以根据具体情境进行更新的多种表征。第二个关键问题是，先验知识的更新，或者在反复举起重量异常的物体时调整举力的能力是否需要集中注意力。为了研究这些问题，我们比较了不同组参与者在全神贯注或注意力分散的情况下，被动（将物体放在手上）或主动（参与者举起物体）体验大小与重量倒置物体时，举起物体和判断物体重量所使用的重量预测的适应性。为了评估重量判断，我们在被动和主动体验倒置物体每20次试验后测量大小-重量错觉。结果发现，举起倒置物体时出现的错觉减弱是情境特定的，即当与倒置物体的交互方式与错觉评估方法相匹配时，错觉减弱幅度更大。在与倒置物体交互过程中分散注意力对错觉减弱没有影响，但确实减缓了举力根据倒置物体重量进行调整的速度。这些发现表明，大脑存储了多种情境特定的先验知识表征，并且集中注意力对于调整举力很重要，但对于更新判断物体重量时所使用的重量预测并不重要。
