Slippage of the attentional beam when searching in space and in time.

"Slippage" of attention in time and space has been studied separately, using visual search (e.g., Snyder, 1972) and rapid serial visual presentation (RSVP) (e.g., McLean, Broadbent, & Broadbent, 1982). The primary purpose of the current study was to see if we could replicate these findings of slippage and if we did, to use individual differences to explore relationships between slippage in the temporal and spatial domains. The participants identified and localized targets in visual search and in RSVP sequences. In Experiment 1, we used visual search and RSVP tasks closely replicating the methods of Snyder and McLean et al. In Experiment 2, we closely equated the two tasks as far as possible while maintaining the crucial space/time difference. Consistent with the previous studies, and reflecting binding errors (or slippage) in both space and time, erroneously reported identities were predominantly from items adjacent to the targets. Correlations between measures of the slippage in space (visual search) and time (RSVP) were near zero, suggesting that different attentional 'beams' bind features in space and time, a possibility that is consistent with other behavioural as well as neuropsychological evidence.

Disrupted object-scene semantics boost scene recall but diminish object recall in drawings from memory.

Humans are highly sensitive to the statistical relationships between features and objects within visual scenes. Inconsistent objects within scenes (e.g., a mailbox in a bedroom) instantly jump out to us and are known to catch our attention. However, it is debated whether such semantic inconsistencies result in boosted memory for the scene, impaired memory, or have no influence on memory. Here, we examined the relationship of scene-object consistencies on memory representations measured through drawings made during recall. Participants (N = 30) were eye-tracked while studying 12 real-world scene images with an added object that was either semantically consistent or inconsistent. After a 6-minute distractor task, they drew the scenes from memory while pen movements were tracked electronically. Online scorers (N = 1,725) rated each drawing for diagnosticity, object detail, spatial detail, and memory errors. Inconsistent scenes were recalled more frequently, but contained less object detail. Further, inconsistent objects elicited more errors reflecting looser memory binding (e.g., migration across images). These results point to a dual effect in memory of boosted global (scene) but diminished local (object) information. Finally, we observed that participants fixate longest on inconsistent objects, but these fixations during study were not correlated with recall performance, time, or drawing order. In sum, these results show a nuanced effect of scene inconsistencies on memory detail during recall.

The Graded Fate of Unattended Stimulus Representations in Visuospatial Working Memory.

As in visual perception, information can be selected for prioritized processing at the expense of unattended representations in visual working memory (VWM). However, what is not clear is whether and how this prioritization degrades the unattended representations. We addressed two hypotheses. First, the representational quality of unattended items could be degraded as a function of the spatial distance to attended information in VWM. Second, the strength with which an item is bound to its location is degraded as a function of the spatial distance to attended information in VWM. To disentangle these possibilities, we designed an experiment in which participants performed a continuous production task in which they memorized a visual array with colored discs, one of which was spatially retro-cued, informing the target location of an impending probe that was to be recalled (Experiment 1). We systematically varied the spatial distance between the cued and probed locations and obtained model-based estimates of the representational quality and binding strengths at varying cue-probe distances. Although the representational quality of the unattended representations remained unaffected by the cue-probe distance, spatially graded binding strengths were observed, as reflected in more spatial confusions at smaller cue-probe distances. These graded binding strengths were further replicated with a model-free approach in a categorical version of the production task in which stimuli and responses consisted of easily discriminable colors (Experiment 2). These results demonstrate that unattended representations are prone to spatial confusions due to spatial degradation of binding strengths in WM, even though they are stored with the same representational quality.