Date of Award


Degree Name

M.A. in Psychology


Traditional information processing theories allow little room for unconscious mental activity. However, a large and growing body of research has been performed in the area of information processing without awareness. Research investigating target detection tasks reveals that perception of targets in a high-load task is a multi-stage, or feature integration process. A multi-stage process indicates that some processing may occur before conscious awareness. Research directed at motor indicants of preconscious processing indicates subjects may indeed process information in a visual target search task prior to consciously discovering the target. Experiments which have looked at rythmic motor responses, such as key tapping, during visual search tasks have discovered subtle differences in the motor response between target-present and target-absent conditions. The underlying mechanism for how preconscious processing can interfere with a motor response may be found in the theory of motor programming. Essentially, the execution of one motor program can be hindered by the partial execution of a second motor program under conditions of uncertainty as in a target search task. The present research examined the use of a key tapping response while subjects searched for numerical targets in a high-load visual target search task. None of the direct measures of on-times and off-times showed a significant difference between target-present and target-absent conditions. However, the distribution of differences of rank-ordered measures of on-times and of off-times showed significant asymmetry between target-present and target-absent conditions. Possible explanations for this result are given within the context of motor programming theory. Weaknesses of the current study and suggestions for future research are discussed.


Motor learning, Subliminal perception, Target acquisition, Task analysis

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Copyright © 1992, author