On the relationship between flanker interference and localized attentional interference

The flanker interference (FI) effect suggests that visual attention operates like a mental spotlight, enhancing all stimuli within a selected region. In contrast, other data suggest difficulty dividing attention between objects near one another in the visual field, an effect termed localized attentional interference (LAI). The present experiment examined the relationship between these phenomena. Observers made speeded identity judgments of a colored target letter embedded among gray fillers. A response-compatible or -incompatible flanker of a non-target color appeared at varying distances from the target. Data gave evidence of LAI and spatially-graded FI, with mean RTs and flanker effects both decreasing with target–flanker separation. Both effects were reduced when target location was pre-cued and when the target was of higher salience than the flanker. Results suggest that the distribution of spatial attention modulates the strength of objects competing for selection, with this competition underlying both the FI and LAI effects.     

Reversal negativity and bistable stimuli: Attention,awareness, or something else?

Ambiguous (or bistable) figures are visual stimuli that have two mutually exclusive perceptual interpretations that spontaneously alternate with each other. Perceptual reversals, as compared with non-reversals, typically elicit a negative difference called reversal negativity (RN), peaking around 250 ms from stimulus onset. The cognitive interpretation of RN remains unclear: it may reflect either bottom-up processes, attentional processes that select between the alternative views of the stimulus, or it may reflect the change in the contents of subjective awareness. In the present study, event-related potentials in response to endogenous unilateral and bilateral reversals of two Necker lattices were compared with exogenously induced reversals of unambiguous lattices. The RN neither resembled the attention-related N2pc response, nor did it correlate with the content of subjective visual awareness. Thus, we conclude that RN is a non-attentional ERP correlate of the changes in the perceptual configuration of the presented object.     

Selective interference with image retention and generation: Evidence for the workspace model

We address three types of model of the relationship between working memory (WM) and long-term memory (LTM): (a) the gateway model, in which WM acts as a gateway between perceptual input and LTM; (b) the unitary model, in which WM is seen as the currently activated areas of LTM; and (c) the workspace model, in which perceptual input activates LTM, and WM acts as a separate workspace for processing and temporary retention of these activated traces. Predictions of these models were tested, focusing on visuospatial working memory and using dual-task methodology to combine two main tasks (visual short-term retention and image generation) with two interference tasks (irrelevant pictures and spatial tapping). The pictures selectively disrupted performance on the generation task, whereas the tapping selectively interfered with the retention task. Results are consistent with the predictions of the workspace model.     

On the generality of the displaywide contingent orienting hypothesis: Can a visual onset capture attention without top-down control settings for displaywide onset?

The contingent orienting hypothesis (Folk, Remington, & Johnston, 1992) states that attentional capture is contingent on top-down control settings induced by task demands. Past studies supporting this hypothesis have identified three kinds of top-down control settings: for target-specific features, for the strategy to search for a singleton, and for visual features in the target display as a whole. Previously, we have found stimulus-driven capture by onset that was not contingent on the first two kinds of settings (Yeh & Liao, 2008). The current study aims to test the third kind: the displaywide contingent orienting hypothesis (Gibson & Kelsey, 1998). Specifically, we ask whether an onset stimulus can still capture attention in the spatial cueing paradigm when attentional control settings for the displaywide onset of the target are excluded by making all letters in the target display emerge from placeholders. Results show that a preceding uninformative onset cue still captured attention to its location in a stimulus-driven fashion, whereas a color cue captured attention only when it was contingent on the setting for displaywide color. These results raise doubts as to the generality of the displaywide contingent orienting hypothesis and help delineate the boundary conditions on this hypothesis.     

Skilled players’ and novices’ difficulty anticipating left- vs. right-handed opponents’ action intentions varies across different points in time

A left-handers’ performance advantage in interactive sports is assumed to result from their relative rarity compared to right-handers. Part of this advantage may be explained by athletes facing difficulties anticipating left-handers’ action intentions, particularly when anticipation is based on kinematic cues available at an early stage of an opponent’s movement. Here we tested whether the type of volleyball attack is predicted better against right- vs. left-handed opponents’ movements and whether such handedness effects are evident at earlier time points in skilled players than novices. In a video-based experiment volleyball players and novices predicted the type of shot (i.e., smash vs. lob) of left- and right-handed volleyball attacks occluded at six different time points. Overall, right-handed attacks were better anticipated than left-handed attacks, volleyball players outperformed novices, and performance improved in later occlusion conditions. Moreover, in skilled players the handedness effect was most pronounced when attacks were occluded 480 ms prior to hand-ball-contact, whereas in novices it was most evident 240 ms prior to hand-ball-contact. Our findings provide further evidence of the effect of an opponent’s handedness on action outcome anticipation and suggest that its occurrence in the course of an opponent’s unfolding action likely depends on an observers’ domain-specific skill.