Document Detail

Time course of perceptual grouping.
MedLine Citation:
PMID:  9038416     Owner:  NLM     Status:  MEDLINE    
An investigation was made of the time course of perceptual grouping that is based on two qualitatively different spatial relationships: proximity and alignment. An index of grouping capacity was used to assess the processing time required before a backward pattern mask interfered with grouping. Stimuli consisted of bistable arrays of disjunct dots that were followed by a mask. Grouping cues, either proximity or alignment, were randomly assigned to either the horizontal or vertical orientation, and subjects indicated whether the dots appeared grouped as a series of horizontal or vertical lines. Spatial metrics of the cues were systematically altered until they no longer served as a cue for grouping thereby determining the grouping threshold. The stimulus onset asynchrony (SOA) of the mask, relative to the test stimulus, ranged from 33.3 to 150 msec. The SOA at which grouping thresholds first became elevated identified the point at which the mask first interfered with the grouping process, thereby identifying the processing time required for grouping by the specified cue. The processing time for grouping by proximity and alignment differed significantly, requiring means of 87.6 and 118.8 msec, respectively, for processing to be completed. These measurements serve to identify the processing time necessary for spatially integrating stimulus elements into unified forms, thereby delineating temporal constraints at this stage of visual processing.
D D Kurylo
Related Documents :
673656 - Opponent hues in visual masking.
15380996 - Is the s-opponent chromatic sub-system sluggish?
1029076 - Attenuation of vibrotactile spatial summation.
512216 - Relationship between psychophysical tuning curves and "suppression".
11430876 - Intergeniculate leaflets lesion delays but does not prevent the integration of photoper...
17688906 - Receptive field properties of neurons in the primary visual cortex under photopic and s...
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Perception & psychophysics     Volume:  59     ISSN:  0031-5117     ISO Abbreviation:  Percept Psychophys     Publication Date:  1997 Jan 
Date Detail:
Created Date:  1997-04-09     Completed Date:  1997-04-09     Revised Date:  2004-11-17    
Medline Journal Info:
Nlm Unique ID:  0200445     Medline TA:  Percept Psychophys     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  142-7     Citation Subset:  C    
Psychology Department, Bowdoin College, Brunswick, ME 04011, USA.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Association Learning*
Distance Perception
Pattern Recognition, Visual*
Perceptual Masking
Reaction Time*
Sensory Thresholds

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Contingent color aftereffects: reassessing old conclusions.
Next Document:  Adaptation to altered visual-vestibular feedback: mechanisms of maintenance and recovery.