Document Detail


Size invariance in visual number discrimination.
MedLine Citation:
PMID:  1792300     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
This study deals with the observer's ability to discriminate the numerosity of two random dot-patterns irrespective of their relative size. One of these two patterns was a reference one that was always composed of 32 dots randomly distributed within a K x K invisible square window (K = 1.92 degrees). The second one was the test pattern with one of the five magnifications (K = 0.64 degrees, 1.28 degrees, 1.92 degrees, 2.56 degrees, 3.20 degrees) and the relative number of dots varied on 11 levels (N = -15, -12, -9, -6, -3, 0, 3, 6, 9, 12, or 15 dots). The observer's task was to indicate which of the two patterns contained more dots. The results show that the stimulus size, as an irrelevant stimulus attribute, can be ignored in the judgements about relative numerosity. This means that the perceived numerosity is size invariant, at least for a 1.6-times magnification and a 3-times reduction of the test pattern. The size invariance observed constrains the range of potential models, since the perceived numerosity can be identified only by means of a feature of the stimulus that will remain invariant after any change in the absolute stimulus size.
Authors:
J Allik; T Tuulmets; P G Vos
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Psychological research     Volume:  53     ISSN:  0340-0727     ISO Abbreviation:  Psychol Res     Publication Date:  1991  
Date Detail:
Created Date:  1992-04-01     Completed Date:  1992-04-01     Revised Date:  2004-11-17    
Medline Journal Info:
Nlm Unique ID:  0435062     Medline TA:  Psychol Res     Country:  GERMANY    
Other Details:
Languages:  eng     Pagination:  290-5     Citation Subset:  IM    
Affiliation:
Department of Psychology, University of Jyväskylä, Finland.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Adult
Attention*
Discrimination Learning*
Humans
Orientation*
Pattern Recognition, Visual*
Psychophysics
Size Perception

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


Previous Document:  The effects of target discriminability and retinal eccentricity on saccade latencies: an analysis in...
Next Document:  Context effects in the processing of familiar faces.