title: The effects of movement direction and hemispace on estimates of distance traveled.
abstract: OBJECTIVE
  The degree of attention directed to a stimulus and the presence of anisometric representations can alter the perception of the magnitude of a stimulus. We wanted to learn if normal right-handed subjects' estimates of distance traveled are influenced by the right-left direction or hemispace of movements.
  
  
  METHODS
  We had blindfolded participants estimate the distance their arm was moved in a rightward or leftward direction, in right and left hemispace. Since we wanted subjects to estimate the distance traveled rather than compute the distance between the start and finish points, the subjects' arms were passively moved in sinusoidal trajectories at a constant speed.
  
  
  RESULTS
  Subjects estimated leftward movements as longer than rightward movements, but there was no effect of hemispace. COMMENTS/CONCLUSIONS: People often attend more to novel than routine conditions and therefore participants might have overestimated the distance associated with leftward versus rightward movement because right-handed people more frequently move their right hand in a rightward direction and learn to read and write using rightward movements. Thus, leftward movements might be more novel and more attended than rightward movements and this enhanced directional attention might have influenced estimates of magnitude (distance).
authors: Department of Neurology, University of Florida College of Medicine, and Malcom Randall Veterans Affairs Medical Center, Gainesville 32610-0236, USA. paul.foster@neurology.ufl.edu
authors: Paul S
authors: PS
authors: Foster
authors: Gregory P
authors: GP
authors: Crucian
authors: Valeria
authors: V
authors: Drago
authors: David W
authors: DW
authors: Burks
authors: Jeannine
authors: J
authors: Mielke
authors: Brian V
authors: BV
authors: Shenal
authors: Robert D
authors: RD
authors: Rhodes
authors: Laura J
authors: LJ
authors: Grande
authors: Kyle
authors: K
authors: Womack
authors: Alonso
authors: A
authors: Riesta
authors: Kenneth M
authors: KM
authors: Heilman
mesh_terms: D000368:Aged; D001288:Attention / Q000502:physiology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D007699:Kinesthesis / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009039:Motion Perception / Q000502:physiology*; D012016:Reference Values; D013028:Space Perception / Q000502:physiology*