title: Illusory line motion in onset and offset bars.
abstract: Illusory line motion (ILM) refers to the perception of motion in a bar that is presented all at once next to an inducing stimulus. The experimental methods for producing and quantifying ILM are varied, and the resulting explanations are likewise at odds. The current study examined the explanations for ILM away from the inducing stimulus (bright or dark flash) using bars that either suddenly appear (onset bars) or suddenly disappear (offset bars). Real motion is used to cancel ILM, providing three measures to quantify ILM: the consistency of responding to only ILM in the absence of real motion; the distance between the points of subjective equality between ILM and the real motion; and the area between the curves relating perception of motion to the real and illusory conditions. ILM quantities for onset and offset bars are strongly correlated when the bar change occurs after the flash. However, onset bars presented during the flash do not show any evidence of ILM, whereas offset bars removed during the flash result in reverse ILM (rILM). Moreover, rILM and ILM are not correlated, suggesting they reflect two separate illusions. These results are consistent over the various measures of ILM.
authors.affiliation: Centre for Brain Research, School of Psychology, The University of Auckland, City Campus, Private Bag 92019, Auckland, New Zealand, 1142.
authors.forename: Sihang
authors.initials: S
authors.lastname: Han
authors.affiliation: Centre for Brain Research, School of Psychology, The University of Auckland, City Campus, Private Bag 92019, Auckland, New Zealand, 1142.
authors.forename: Zhuoying
authors.initials: Z
authors.lastname: Zhu
authors.affiliation: Centre for Brain Research, School of Psychology, The University of Auckland, City Campus, Private Bag 92019, Auckland, New Zealand, 1142.
authors.forename: Michael C
authors.initials: MC
authors.lastname: Corballis
authors.affiliation: Centre for Brain Research, School of Psychology, The University of Auckland, City Campus, Private Bag 92019, Auckland, New Zealand, 1142. j.hamm@auckland.ac.nz.
authors.forename: Jeff P
authors.initials: JP
authors.lastname: Hamm
mesh_terms: D000293:Adolescent; D000328:Adult; D001288:Attention / Q000502:physiology*; D003463:Cues; D003657:Decision Making / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D009039:Motion Perception / Q000502:physiology*; D009903:Optical Illusions / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods; D011930:Reaction Time / Q000502:physiology; D055815:Young Adult
keywords: Attention; Illusory line motion; Motion perception