Lateralized Asymmetrical Processing During Visual Change Detection

see1The lateralization of visual processing between the hemispheres is a paradigm commonly applied to hierarchical visual image processing (Hellige, 1996). In fact, lesions to the temporal-parietal left hemisphere have been noted to disrupt local-level (i.e. fine detail) processing, while lesions to the temporal-parietal area of the right hemisphere have caused deficits in global-level (i.e. big picture) visual processing (Lamb et al., 1989).

Despite this, previous behavioral, functional, and event-related potential (ERP) research has provided conflicting evidence for the existence of differences in the processing of visual information across the hemispheres (Han, et al., 2002).

Some modulating factors affecting the lateralization of hierarchical visual information have been identified, such as spatial frequency and position of presentation (i.e. unilateral vs. bilateral presentation) (Han et al. 2002). Furthermore, Keita et al. (2014) have suggested that the occurrence of lateralized asymmetry is dependent on stimulus category. The present study sought to behaviorally assess the presence of asymmetric lateralization of processing in a divided attention change-detection task using directional stimuli.

The findings were consistent with some previous research assessing asymmetrical processing of hierarchical stimuli. In this case, a change detection task was used to examine to what extent lateralized processing occurs at higher levels of processing compared to simpler target detection tasks. It was found that at these higher levels of processing, no lateralized processing of object-based stimuli occurs. It is interesting to note, however, that the global precedence effect persists. Participants responded to global change with significantly greater accuracy, and with greater speed approaching significance.

Created by Connor Burrows

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