Edwards Louisa M, Causby Ryan S, Stewart Halton, Stanton Tasha R
School of Health Sciences, University of South Australia, G.P.O. Box 2471, Adelaide, SA, 5001, Australia.
Neuro Orthopaedic Institute (NOI), 19 North Street, Adelaide, SA, 5000, Australia.
Exp Brain Res. 2019 May;237(5):1325-1337. doi: 10.1007/s00221-019-05512-3. Epub 2019 Mar 14.
Left/right judgement (LRJ) tasks involve determining the laterality of presented hand or feet images. Allocentric images (third-person perspective; 3PP) take longer to identify than egocentric images (first-person perspective; 1PP), supporting that implicit motor imagery (IMI)-mentally manoeuvring one's body to match the shown posture-is used. While numerous cognitive processes are involved during LRJs, it remains unclear whether features of the individual (e.g., visual exposure, experience, task-dependent use) influence the type of recognition strategy used during LRJs (IMI versus non-IMI). To investigate whether an individual's routine visual exposure to hands/feet in 3PP disrupts the typical perspective-reaction time (RT) relationship in LRJs, hand therapists, podiatrists, and healthy controls completed online LRJ tasks of hand and feet images. A group-specific reduction in RT for only allocentric images would represent a switch to non-IMI strategies. The results show that routine visual exposure to feet in 3PP (podiatrists) results in quicker RTs only for allocentric images of feet, suggesting a switch from IMI to non-IMI (e.g., visual object-based recognition) strategies. In contrast, routine visual exposure to hands in 3PP (hand therapists) does not alter RT for allocentric images, suggesting maintenance of IMI. However, hand therapists have quicker RTs (vs other groups) for egocentric hand images, supporting enhanced sensorimotor processing for the hand, consistent with task-dependent use (precise hand use). Higher accuracy in health professionals (vs control) on both tasks supports enhanced body schema. Combined, this suggests that 3PP visual exposure to body parts and task-dependent use contribute to LRJ performance/recognition strategy.
左右判断（LRJ）任务涉及确定所呈现的手或脚图像的左右侧性。从异我中心视角（第三人称视角；3PP）识别图像比从自我中心视角（第一人称视角；1PP）识别花费的时间更长，这支持了人们会使用内隐运动想象（IMI）——即在脑海中操纵自己的身体以匹配所展示的姿势。虽然在LRJ过程中涉及众多认知过程，但尚不清楚个体特征（如视觉暴露、经验、任务相关使用情况）是否会影响LRJ过程中所使用的识别策略类型（IMI与非IMI）。为了研究个体日常从3PP视角对双手/双脚的视觉暴露是否会扰乱LRJ中典型的视角 - 反应时间（RT）关系，手部治疗师、足病医生和健康对照者完成了关于手和脚图像的在线LRJ任务。仅针对异我中心图像的特定组RT降低将代表转向非IMI策略。结果表明，日常从3PP视角对双脚的视觉暴露（足病医生）仅导致对异我中心视角的脚部图像反应更快，这表明从IMI策略转向了非IMI策略（如基于视觉对象的识别）。相比之下，日常从3PP视角对双手的视觉暴露（手部治疗师）并未改变对异我中心图像的RT，这表明维持了IMI策略。然而，手部治疗师对自我中心视角的手部图像反应更快（与其他组相比），这支持了手部感觉运动处理能力的增强，这与任务相关使用情况（精确的手部使用）一致。健康专业人员在两项任务上的准确率更高（与对照组相比），这支持了身体图式的增强。综合来看，这表明从3PP视角对身体部位的视觉暴露和任务相关使用情况有助于LRJ表现/识别策略。
