Visual demand and visual field presentation influence natural scene processing
- نوع فایل : کتاب
- زبان : انگلیسی
- مؤلف : Olivier A. Coubard & Céline Perez & Seta Kazandjian & Isabelle Gaudry & Christian Marendaz & Nathalie Guyader & Carole Peyrin & Sylvie Chokron
- چاپ و سال / کشور: 2010
Description
Background Bottom-up and top-down processes are involved in visual analysis of scenes. Here we examined the influence of top-down visual demand on natural scene processing. Methods We measured accuracy and response time in adults performing two stimuli-equivalent tasks. Unfiltered, low or high spatial frequency (SF) natural scenes were presented in central, left, or right visual fields (CVF, LVF, RVF). The tasks differed only by the instructed visual demand. In the detection task, participants had to decide whether a scene was present or not. In the categorization task, they had to decide whether the scene was a city or a forest. Results Higher accuracy was seen for the LVF in the detection task, but for categorization, greater accuracy was seen for the RVF. The interaction between Task and SF revealed coarse-tofine processing in the categorization task for both accuracy and reaction time, which nearly disappeared in the detection task. Considering the interaction of Task, VF and SF, a lefthemisphere specialisation (i.e., RVF advantage) was observed for the categorisation of HSF scenes for accuracy alone, whereas a LVF advantage was seen for all SFs in the detection task for both accuracy and reaction time. Conclusion Our results revealed that the nature of top-down visual demand is essential to understanding how visual analysis is achieved in each hemisphere. Moreover, this study examining the effects of visual demand, visual field presentation, and SF content of stimuli through the use of ecological stimuli provides a tool to enrich the clinical examination of visual and neurovisual patients.
Graefes Arch Clin Exp Ophthalmol (2011) 249:223–232 DOI 10.1007/s00417-010-1451-5 Received: 24 February 2010 / Revised: 18 May 2010 / Accepted: 4 July 2010 / Published online: 23 July 2010
