Visual search, the process of detecting relevant items within an environment, is a vital skill required for navigating one’s visual environment as well as for careers, such as radiology and airport security, that rely upon accurate searching. Research over the course of several decades has established that visual search requires the integration of low- and high-level cognitive processes, including sensory analysis, attentional allocation, target discrimination, and decision-making. Search abilities are malleable and vary in accordance with long-term experiences, direct practice, and contextual factors in the immediate environment; however, the mechanisms responsible for changes in search performance remain largely unclear. A series of studies examine variation in visual search abilities and performance and aim to identify the underlying mechanisms. To assess differences associated with long-term experiences, visual search performance is compared between laypersons (typically undergraduates) and specific populations, including radiologists and avid action video game players. Behavioral markers of search processes are used to elucidate causes of enhanced search performance. To assess differences associated with direct practice, laypersons perform a visual search task over five consecutive days, and electrophysiological activity is recorded from the scalp on the first and last days of the protocol. Electrophysiological markers associated with specific stages of processing are analyzed to determine neurocognitive changes contributing to improved performance. To assess differences associated with contextual factors, laypersons are randomly assigned to experimental conditions in which they complete a visual search task within a particular framework or in the presence or absence of motivation, feedback, and/or time pressure. Results demonstrate that search abilities can improve through experience and direct training, but the mechanisms underlying effects in each case are different. Longterm experiences are associated with strategic attentional allocation, but direct training can improve low-level sensory analysis in addition to higher-level processes. Results also demonstrate nuanced effects of experience and context. On searches that contain multiple targets, task framework impacts accuracy for detecting additional targets after one target has been identified. The combination of motivation and feedback enhances accuracy for both single- and multiple-target searches. Implications for cognitive theory and applications to occupational protocols are discussed.
Clark, K. Variation in visual search abilities and performance. (Thesis). Duke University. Retrieved from https://uwe-repository.worktribe.com/output/819950