title: Dominance dynamics of competition between intrinsic and extrinsic grouping cues.
abstract: In the present study we examined the dominance dynamics of perceptual grouping cues. We used a paradigm in which participants selectively attended to perceptual groups based on several grouping cues in different blocks of trials. In each block, single and competing grouping cues were presented under different exposure durations (50, 150 or 350ms). Using this procedure, intrinsic vs. intrinsic cues (i.e. proximity and shape similarity) were compared in Experiment 1; extrinsic vs. extrinsic cues (i.e. common region and connectedness) in Experiment 2; and intrinsic vs. extrinsic cues (i.e. common region and shape similarity) in Experiment 3. The results showed that in Experiment 1, no dominance of any grouping cue was found: shape similarity and proximity grouping cues showed similar reaction times (RTs) and interference effects. In contrast, in Experiments 2 and 3, common region dominated processing: (i) RTs to common region were shorter than those to connectedness (Exp. 2) or shape similarity (Exp. 3); and (ii) when the grouping cues competed, common region interfered with connectedness (Exp. 2) and shape similarity (Exp. 3) more than vice versa. The results showed that the exposure duration of stimuli only affected the connectedness grouping cue. An important result of our experiments indicates that when two grouping cues compete, both the non-attended intrinsic cue in Experiment 1, and the non-dominant extrinsic cue in Experiments 2 and 3, are still perceived and they are not completely lost.
authors.affiliation: Departamento de Psicología Básica I, UNED, Spain. Electronic address: mluna@psi.uned.es.
authors.forename: Dolores
authors.initials: D
authors.lastname: Luna
authors.affiliation: Instituto Pluridisciplinar, Universidad Complutense de Madrid, Spain; Departamento de Psicología Básica I, Universidad Complutense de Madrid, Spain.
authors.forename: Cristina
authors.initials: C
authors.lastname: Villalba-García
authors.affiliation: Departamento de Psicología Básica I, UNED, Spain.
authors.forename: Pedro R
authors.initials: PR
authors.lastname: Montoro
authors.affiliation: Instituto Pluridisciplinar, Universidad Complutense de Madrid, Spain; Departamento de Psicología Básica I, Universidad Complutense de Madrid, Spain.
authors.forename: José A
authors.initials: JA
authors.lastname: Hinojosa
mesh_terms: D000328:Adult; D003463:Cues; D005260:Female; D005556:Form Perception / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult
keywords: Competition; Dominance dynamics; Extrinsic principles; Gestalt; Intrinsic principles; Perceptual grouping