Introduction to Cognitive Psychology - Department of Psychological ...

Prof. Greg Francis 1/2/13Feature SearchFeature SearchBut if the target differs from the distracters in the right way,search can be fast even with lots of distractersBut if the target differs from the distracters in the right way,search can be fast even with lots of distracters pop out pop outThis often happens when the target has a unique featureThis often happens when the target has a unique featurerelative to the distractersrelative to the distracters shape colorPurdue UniversityPurdue UniversityConjunctive SearchVisual search experimentBut if the target has shared features with differentdistracters, search is difficult No pop outThis often happens when the target is defined by aconjunction of features relative to the distracters Orange rectangle: color and shapeFour types of responses 1) Feature - present (can respond as soon as see target) 2) Feature - absent (must examine all stimuli before suretarget is not present) 3) Conjunctive - present (can respond as soon as seetarget) 4) Conjunctive - absent (must examine all stimuli beforesure target is not present)Purdue UniversityPurdue UniversityCogLab feature searchCogLab feature searchFew distracters -easyMany distracters - still easyPurdue UniversityPurdue UniversityPSY 200: Intro. to Cognitive Psychology 3