Interference and visual search in young and older adults.
Published: 2005
Language: eng
Number of pages: 190
Description: For decades, psychologists have debated the question of whether human cognition occurs through 'serial discrete' processing stages (Sternberg, 1969), or rather is continuous and parallel in nature (Eriksen & Schultz, 1979). The present dissertation addresses this question within the realm of visual selective attention. A novel methodological approach contrasts reaction time performance across the two main experimental paradigms used in selective attention research: Filtering and visual search (Wickens, 1992).Taken together, these results favour the continuous transmission model as a more viable account for processing that is required during visual selective attention. In addition, the greater accrual of irrelevant information under search conditions has implications for performance, especially among older adults. Finally, methodological implications for research in visual selective attention are discussed.Through administration of the experimental task to older adults (age 65+) significant age-related elevations in response interference are identified for high-similarity trials in both filtering and search conditions. Additional experimentation with young adults uses a deficit-modeling approach to provide explanations for these age-related elevations in response interference. Under search conditions the performance of older adults is consistent with compromise in the ability to discriminate target information from noise (Allen, Weber, & Madden, 1994), while performance under filtering conditions is best accounted for by an age-related deficit in the ability to maintain focal attention at a constant display location.Using modified Eriksen flanker tasks (C.W. Eriksen & B.A. Eriksen, 1974), four separate experiments show evidence for interference effects that are significantly greater under search conditions relative to effects obtained when the same tasks are administered under filtering conditions. The accrual of response information from non-target items during the search interval (prior to target selection) refutes the assumptions of serial discrete processing models. Additional experiments indicate that this effect is influenced by the degree of perceptual similarity between target and flanker stimuli, as well as by location uncertainty.
Notes: Source: Dissertation Abstracts International, Volume: 66-10, Section: B, page: 5700.

Thesis (Ph.D.)--University of Toronto, 2005.

Electronic version licensed for access by U. of T. users.