Attention to Locations and Objects

Psy315 - Class 11, Part 1

(This page last updated 12 October, 2006.)

Two Kinds of Attention

• Overt Attention - eye movements
• Covert Attention - shifts of attention within a fixation

Attention to Locations

Spatial Cuing

• First experiments by Charles Eriksen and his students.
• Other experiments by Posner
• Primarily used to study covert attention

 

	One Method of Spatial Cuing Cue consists of one square brightening for a brief period. Equally likely to be left or right. Target stimulus (square) appears after cue Press button as soon as you see target stimulus. Target stimulus more likely to be in cued rectangle than in uncued rectangle.
	Another Method of Spatial Cuing Cued side indicated by arrow at center.

 For both methods, faster to respond to test stimulus when it appears at cued location.

Posner compares attention to a spotlight, because it selects information based on its location.

Attention to Objects

Spatial cuing experiments show clearly that attention can be allocated to locations.

Other experiments demonstrate that attention can be allocated to objects.

Experiment by Egly, Driver, and Rafal. Beginning Display
One end of one of the rectangles is cued by brightening it.
Test stimulus is square that appears at one end of one of the rectangles. Most likely to appear at cued location. Fastest response to stimuli at cued location.
Responses for other location on same object slower.
Responses for location on other object still slower, showing cost for shifting objects.

This single experiment shows both location effects and object-boundary effects.

Attention is both location-based and object-based.

next topic: Visual Search

Psych 315: Cognitive Psychology Kyle Cave Psychology Dept. U. Mass.