Abstract
Many theories of visual attention propose that we select sought-for items (targets) by tuning attention to their elementary features (e.g., green, yellow). However, recent findings showed that we often select a target in a context-dependent manner, by tuning attention to its relative features, that is, to the features that the target has relative to the surrounding non-target items (e.g., greener, yellower). In our Experiment 1, we replicated these basic findings, employing a cueing paradigm with spatially unpredictive pre-cues. Target and nontarget colors remained fixed in a block of trials (e.g., yellowish-green and green), so that also the relative color remained constant (e.g., yellower). Consistent with a relational account, we found that the cues elicited cueing effects only when they had the same relative color as the target (e.g., yellowest item), regardless of whether the cues had the same elementary color as the target or not (e.g., yellowish-green or yellow). Critically, cues that mis-matched both, the target's elementary and relative color (e.g., a green cue among yellowish-green contextual cues), elicited inverse cueing effects, that is, slower RTs in cued than uncued trials. It has been hypothesized that these effects might be attributable to suppression of the cue color or, alternatively, to capture by the contextual cues, as those had the same elementary and relative color as the target. In Experiment 2, we added a white cue to each cue array. We assumed that this color would neither be attentionally enhanced nor suppressed. Hence, trials in which white cues preceded at the target location were regarded as baseline. We found that RTs were slower than baseline when the mis-matching cue preceded the target location, but faster than baseline when the matching contextual cues preceded the target location. Thus, the results suggest that inverse effects are the result of combined suppression and enhancement.
Meeting abstract presented at VSS 2017