Abstract
Visual search is guided by past experience of regularities in our visual environment. In the contextual cueing paradigm, incidental learning of repeated distractor configurations improves search times and eye movement parameters. Both in patients with age-related macular degeneration who suffer from foveal vision loss and in young normal-sighted observers with gaze-contingent central scotoma simulation contextual cueing was severely reduced (Geringswald et al., Front Hum Neurosci 2012, J Vis 2014). Previous work has shown that not the learning of spatial contexts but rather the utilization of previously learned context for efficient search guidance depends on visuospatial working-memory (Manginelli et al., Att Percept Psychophys 2013; Vickery et al., J Exp Psychol Hum Perc Perform 2010). Therefore, increased working memory demands due to top-down controlled visual search in the presence of foveal vision loss could lead to reduced contextual cueing. To test this hypothesis, we let normal-sighted observers search with simulated foveal scotoma during a learning phase but without scotoma in a subsequent transfer phase. Contextual cueing was absent during learning, but reinstated in the transfer phase. This indicated that context learning occured in the presence of foveal vision loss, but learning could not be utilized for more efficient search while the scotoma was present. However, in a further experiment, after few hours of search training with central scotoma simulation, contextual cueing was reinstated during scotomatous search, indicating that contextual cueing can be regained when the exploration of the environment becomes more automatic. Thus, foveal vision loss leads to inefficient use of implicitly learned contextual cues for the guidance of visual search. Automatization of search with a simulated scotoma leads to reinstatement of contextual cueing in normal-sighted observers. This may show a promising way for training programs in patients with foveal vision loss.
Meeting abstract presented at VSS 2015