Crawford, John DouglasPor Davoody, Niousha2025-04-102025-04-102024-12-182025-04-10https://hdl.handle.net/10315/42855While many studies have examined reach-to-grasp movements, the placement component remains less explored. Grasping and placing tasks share some common characteristics, such as precise localization and orientation of the hand, but differ in cognitive intent and sensory feedback, with grasping relying more on visual input and placing on somatosensory feedback relative to surroundings. This study employs a within-subjects 2x2x2 design, examining the effects of Task (grasp vs. place), Object Orientation (clockwise vs. counterclockwise), and Target Location (left vs. right) in right-handed participants performing in near-total darkness. Each participant completed 160 randomized trials across eight conditions, tracking hand and eye movements via an OptiTrack system and eye tracker. Results revealed significant main effects for Task, Location, and Orientation, along with notable interactions. Contrary to the hypothesis, placing tasks were faster than grasping tasks and exhibited higher orientation errors. This result contradicts the expectation that placement would require more precise alignment, suggesting that the simplified placement task used in this study may rely more on visual feedback, which was absent, compared to grasping. Movements toward the right showed faster velocities and fewer errors, reflecting hemispheric motor advantages, while clockwise orientations were associated with lower orientation errors compared to counterclockwise orientations. Interaction effects between Location and Orientation influenced certain variables, highlighting the role of spatial and alignment demands in motor control. These findings suggest that while grasping and placing tasks share overlapping motor control processes, they also engage distinct mechanisms under specific spatial conditions.Author owns copyright, except where explicitly noted. Please contact the author directly with licensing requests.Electronic Thesis or Dissertation2025-04-10ReachGraspKinematic