Abstract
Visual attention can be guided by past experience of regularities in our visual environment. In the contextual cueing paradigm (Chun & Jiang, Cogn. Psychol. 36, 28–71, 1998), incidental learning of repeated distractor configurations speeds up response times compared to random search arrays. Concomitantly, fewer fixations and more direct scan paths indicate more efficient visual exploration in repeated search arrays (Manginelli and Pollmann, Psychol. Res. 73, 212–221, 2009). In previous work, we found that simulating a central scotoma in healthy observers eliminated this search facilitation (Geringswald, Baumgartner & Pollmann, Front. Hum. Neurosci. 6, 134, 2012), likely due to a more top-down controlled exploration of the search displays. Here, we investigated contextual cueing in patients with age-related macular degeneration (AMD) who suffer from impaired foveal vision and may show a similar lack of contextual cueing. AMD patients performed visual search using only their more severely impaired eye (n=13) as well as under binocular viewing (n=16). Patient data were compared to sex- and age-matched controls who searched in perceptually more demanding displays equalizing search difficulty. Controls developed a significant contextual cueing effect. In comparison, patients' monocular as well as binocular search showed only a small but non-significant advantage for repeated displays. Number of fixations and scan pattern ratios showed a comparable pattern as search times. However, contextual cueing was significantly correlated with acuity. Thus, contextual cueing was not observed in AMD patients as a group, but it depended on acuity in that mild cases benefited more from context cues. A deficit of foveal vision appears to interfere with the implicit guidance of attention by contextual cues. This may be caused by a more top-down controlled exploration that interferes with a more bottom-up driven exploration that uses implicit memory cues (Lleras and von Muehlenen, Spat. Vis. 17, 465–482, 2004).
Meeting abstract presented at VSS 2013