Reply to Theeuwes: Fast Feature-based Top-down Effects, but Saliency May be Slow

Attention to Changes on a Head-Worn Display: Two Preclinical Studies with Healthcare Scenarios

OBJECTIVE

In two experiments, we examined how quickly different visual alerts on a head-worn display (HWD) would capture participants' attention to a matrix of patient vital sign values, while multitasking.

BACKGROUND

An HWD could help clinicians monitor multiple patients, regardless of where the clinician is located. We sought effective ways for HWDs to alert multitasking wearers to important events.

METHODS

In two preclinical experiments, university student participants performed a visuomotor tracking task while simultaneously monitoring simulated patient vital signs on an HWD to detect abnormal values. Methods to attract attention to abnormal values included highlighting abnormal vital signs and imposing a white flash over the entire display.

RESULTS

Experiment 1 found that participants detected abnormal values faster with high contrast than low contrast greyscale highlights, even while performing difficult tracking. In Experiment 2, a white flash of the entire screen quickly and reliably captured attention to vital signs, but less so on an HWD than on a conventional screen.

CONCLUSION

Visual alerts on HWDs can direct users' attention to patient transition events (PTEs) even under high visual-perceptual load, but not as quickly as visual alerts on fixed displays. Aspects of the results have since been tested in a healthcare context.

APPLICATION

Potential applications include informing the design of HWD interfaces for monitoring multiple processes and informing future research on capturing attention to HWDs.

Attention and platypuses

This perspective piece discusses a set of attentional phenomena that are not easily accommodated within current theories of attentional selection. We call these phenomena attentional platypuses, as they allude to an observation that within biological taxonomies the platypus does not fit into either mammal or bird categories. Similarly, attentional phenomena that do not fit neatly within current attentional models suggest that current models are in need of a revision. We list a few instances of the "attentional platypuses" and then offer a new approach, that we term dynamically weighted prioritization, stipulating that multiple factors impinge onto the attentional priority map, each with a corresponding weight. The interaction between factors and their corresponding weights determines the current state of the priority map which subsequently constrains/guides attentional allocation. We propose that this new approach should be considered as a supplement to existing models of attention, especially those that emphasize categorical organizations. This article is categorized under: Psychology > Attention Psychology > Perception and Psychophysics Neuroscience > Cognition.

The attentional template in high and low similarity search: Optimal tuning or tuning to relations?

The attentional template is often described as the mental representation that drives attentional selection and guidance, for instance, in visual search. Recent research suggests that this template is not a veridical representation of the sought-for target, but instead an altered representation that allows more efficient search. The current paper contrasts two such theories. Firstly, the Optimal Tuning account which posits that the attentional template shifts to an exaggerated target value to maximise the signal-to-noise ratio between similar targets and non-targets. Secondly, the Relational account which states that instead of tuning to feature values, attention is directed to the relative value created by the search context, e.g. all redder items or the reddest item. Both theories are empirically supported, but used different paradigms (perceptual decision tasks vs. visual search), and different attentional measures (probe response accuracy vs. gaze capture). The current design incorporates both paradigms and measures. The results reveal that while Optimal Tuning shifts are observed in probe trials they do not drive early attention or eye- movement behaviour in visual search. Instead, early attention follows the Relational Account, selecting all items with the relative target colour (e.g., redder). This suggests that the masked probe trials used in Optimal Tuning do not probe the attentional template that guides attention. In Experiment 3 we find that optimal tuning shifts correspond in magnitude to purely perceptual shifts created by contrast biases in the visual search arrays. This suggests that the shift in probe responses may in fact be a perceptual artefact rather than a strategic adaptation to optimise the signal-to-noise ratio. These results highlight the distinction between early attentional mechanisms and later, target identification mechanisms. SIGNIFICANCE STATEMENT: Classical theories of attention suggest that attention is guided by a feature-specific target template. In recent designs this has been challenged by an apparent non- veridical tuning of the template in situations where the target stimulus is similar to non-targets. The current studies compare two theories that propose different explanations for non-veridical tuning; the Relational and the Optimal Tuning account. We show that the Relational account describes the mechanism that guides early search behaviour, while the Optimal Tuning account describes perceptual decision-making. Optimal Tuning effects may be due to an artefact that has not been described in visual search before (simultaneous contrast).

Testing a priming account of the contingent-capture effect

In the contingent-capture protocol, singleton cues that have a target's searched-for feature capture attention, but cues that do not have the target's searched-for feature do not, a result labeled the contingent-capture effect. The contingent-capture effect is usually regarded as evidence for the observers' ability to establish search settings for certain nonspatial features in a top-down manner. However, in recent years it has become increasingly clear that selection history is also a powerful mediator of attentional capture. In this vein, it has been suggested that contingent-capture effects could emerge as a result of (intertrial) priming: The idea is that features that have been encountered previously in the target are primed, so that cues that have these features automatically capture attention in a subsequent encounter. Here we tested a strong version of the priming account of the contingent-capture effect. We wanted to know whether cues that had target features would capture attention when the corresponding features were not part of the instructions (i.e., when the corresponding features were task-irrelevant). The results suggested that a strong version of the priming account of contingent capture is not supported. In five experiments, we found little evidence that the contingent-capture effect could be explained by (intertrial) priming of task-irrelevant features alone. These results show that processes beyond priming through task-irrelevant features are critical for contingent-capture effects.

Visual Selection: Usually Fast and Automatic; Seldom Slow and Volitional; A Reply to Commentaries

In this reply I react to the commentaries of my colleagues to my review article "Visual Selection: Usually Fast and Automatic; Seldom Slow and Volitional" (Theeuwes, 2018). I have organized the reply into separate sections and discuss issues that were commonly raised.