Biomaterial Database

Detection versus discrimination of visual orientation. 1984

D Sagi, and B Julesz

The role of focused attention in vision is examined. Recent theories of attention hypothesize that serial search by focal attention is required for discrimination between different combinations of features. Experiments are reported which show that the mixture of a few (less than five) horizontal and vertical line segments embedded in an aggregate of diagonal line segments can be rapidly counted (also called 'subitizing') by a parallel (preattentive) process, while the discrimination between horizontal and vertical orientation requires serial search by shifting focal attention to each line segment. Thus detecting and counting targets that differ in orientation can be done in parallel by a preattentive process, whereas knowing 'what' the orientation of a target is (horizontal or vertical, ie of a single conspicuous feature) requires a serial search by focal attention.

UI	MeSH Term	Description	Entries
D008960	Models, Psychological	Theoretical representations that simulate psychological processes and/or social processes. These include the use of mathematical equations, computers, and other electronic equipment.	Model, Mental,Model, Psychological,Models, Mental,Models, Psychologic,Psychological Models,Mental Model,Mental Models,Model, Psychologic,Psychologic Model,Psychologic Models,Psychological Model
D010470	Perceptual Masking	The interference of one perceptual stimulus with another causing a decrease or lessening in perceptual effectiveness.	Masking, Perceptual,Maskings, Perceptual,Perceptual Maskings
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D001288	Attention	Focusing on certain aspects of current experience to the exclusion of others. It is the act of heeding or taking notice or concentrating.	Focus of Attention,Selective Attention,Social Attention,Attention Focus,Attention, Selective,Attention, Social,Selective Attentions
D013028	Space Perception	The awareness of the spatial properties of objects; includes physical space.	Perception, Space,Perceptions, Space,Space Perceptions
D013997	Time Factors	Elements of limited time intervals, contributing to particular results or situations.	Time Series,Factor, Time,Time Factor
D014796	Visual Perception	The selecting and organizing of visual stimuli based on the individual's past experience.	Visual Processing,Perception, Visual,Processing, Visual