S u m m a r y

Laarni J (1998)

Is attention necessary in vision?

Psykologia 33(4-5):283-292. Helsinki ISSN 0355-1067.

 

Even though the amount of information gathered during a single fixation is limited, our experience of the visual world is unified. Moreover, even though individual visual features are represented at several distinct modules in the cortex, our perceptions of visual objects are perceptions of a set of unified and ordered properties. In unifying perception both focal attention and eye movements have a central role: A mental map is build up by the information taken in by saccades, and the properties of objects are glued together by attention.

We can also selectively attend to one object and at the same time we are able to detect important changes elsewhere in the visual field. To find targets in a crowded visual world our visual system simply discards much incoming information. Since visual acuity drops as the function of eccentricity, the details of a stimulus are processed only at the centre of the visual field. Another approach is to process information selectively. Thus, attention is guided towards distinctive items in the visual field in a stimulus-driven involuntary manner. On the other hand, it can be directed to a particular object or location in a goal-directed voluntary manner. Recent evidence suggest that voluntary top-down control has a more prominent role than has been thought.

 

Key words:

Visual perception, attention, binding problem, selection.

 

Jari Laarni, Ph.D., Department of Psychology, General Psychology Division, University of Helsinki, PO BOX 13 (Meritullinkatu 1), 00014 niversity of Helsinki.