Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6-7
pubmed:dateCreated
2006-1-2
pubmed:abstractText
We investigated two types of spatial resolution for perceiving motion-defined contours: grating acuity, the capacity to discriminate alternating stripes of opposed motion from transparent bi-directional motion; and alignment acuity, the capacity to localize the position of motion-defined edges with respect to stationary markers. For both tasks the stimuli were random noise patterns, low-pass filtered in the spatial dimension parallel to the motion. Both grating and alignment resolution varied systematically with spatial frequency cutoff and speed. Best performance for grating resolution was about 10 c/deg (for unfiltered patterns moving at 1-4 deg/s), corresponding to a stripe resolution of about 3'. Grating resolution corresponds well to estimates of smallest receptive field size of motion units under these conditions, suggesting that opposing signals from units with small receptive fields (probably located in V1) are contrasted efficiently to define edges. Alignment resolution was about 2' at best, under similar conditions. Whereas alignment judgment based on luminance-defined edges is typically 3-10 times better than resolution, alignment based on motion-defined edges is only 1.1-1.5 times better, suggesting motion contours are less effectively encoded than luminance contours.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0042-6989
pubmed:author
pubmed:issnType
Print
pubmed:volume
46
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
932-9
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Resolution for spatial segregation and spatial localization by motion signals.
pubmed:affiliation
Dipartimento di Psicologia, Università di Firenze, Via S. Nicolò 89, Italy. dave@in.cnr.it
pubmed:publicationType
Journal Article