PS260 Chapter Notes - Chapter 4: Agnosia, Simple Features, Bigram
Document Summary
Apperceptive agnosia: a disorder involving a failure in object recognition apparently caused by difficulties in assembling the part of an image into an understandable whole. Associative agnosia is where perception occurs but recognition still does not occur. (integrative agnosia all together) Processes that are directly shaped by the stimulus are data driven but are more commonly termed bottom-up processes. Processes shaped by knowledge are called top-down processes. The importance of features: recognition begins with the identification of visual features. Word recognition: after detection of simple features, separate mechanisms are needed to put the features together, assembling them into complete objects. They used to do this with a tachitoscope: a device designed to present stimuli for precisely controlled amounts of time. A post-stimulus mask followed each stimulus: a random jumble of letters, such as, xjdkel. the mask serves to interrupt any continued processing that participants might try to do for the stimulus just presented.
