Abstract
How do the limits of peripheral vision versus the effects of attentional selection influence change blindness? We investigated this in four Experiments. We first characterizing the difficulty of numerous change blindness demonstrations using the standard Flicker paradigm in Experiment 1. Experiment 2 evaluated viewers’ ability to peripherally discriminate change pairs of varying difficulty when changes were fully attended. We first showed participants a change. Participants then fixated predetermined locations, 1.25-10 degrees eccentricity from each change, and performed a peripheral ABX discrimination task for versions A and B. Discrimination performance declined with increasing eccentricity for changes “difficult” to find in the Flicker paradigm, but “easy” changes showed little effect of eccentricity. Experiment 3 simulated the effects of crowding in peripheral vision using the Texture Tiling Model (TTM). We created “mongrel” texture versions of each image pair, with simulated “foveation” at each of the fixation locations and eccentricities of Experiment 2. Participants’ discriminated whether each mongrel was generated from image version A or B. Performance decreased with simulated eccentricity, with a steeper slope for “difficult” change pairs than “easy” pairs, suggesting that peripheral information loss partially explains change blindness. In Experiment 4, we manipulated attention to the change by manipulating participants’ knowledge of the change before the ABX peripheral task. The pre-cued condition (same as Experiment 2) replicated the finding that the changes easiest to peripherally discriminate were those easiest to find in the Flicker paradigm. However, un-cued “difficult” changes were uniformly poorly discriminated at all eccentricities, and “easy” changes were only above-chance at 1.25 deg eccentricity. This suggests that change detection involves two stages: 1) attending to the change; 2) peripherally or foveally discriminating the two versions. Thus, both attentional selection and the limitations of peripheral vision influence change detection. The latter can be roughly approximated by the TTM.