EXPRESS: High Bladder Pressure Reduces the Ability to Filter Out Interference From Distractors in Low Perceptual Load Condition

According to the load theory of attention, an active cognitive control mechanism is needed to ensure that behavior is controlled by target-relevant information when distractors are also perceived. Although the active cognitive control mechanism consists of working memory, cognitive flexibility, and inhibition components, predictions regarding the load effects of this mechanism were derived mostly from studies on working memory. We aimed to test whether these predictions are also valid for an inhibition component. The inhibitory load was manipulated physiologically by creating different bladder pressure and its effects on distractor interference were examined under low and high perceptual load conditions. Results indicated that the availability of inhibitory control resources was important for decreasing the interference of distractors in the low perceptual load condition and that the high perceptual load reduced the effects of distractors independently from the availability of inhibitory resources. Results were consistent with the predictions of load theory, and to the best of our knowledge, the study provided the first piece of evidence in terms of the load effect of inhibition component on distractor interference.

Attention Capture by Angry Faces Depends on the Distribution of Attention

<p>The threat-capture hypothesis posits a threat-detection system that automatically directs visual attention to threat-related stimuli (e.g., angry facial expressions) in the environment. Importantly, this system is theorised to operate preattentively, processing all input across the visual field in parallel, prior to the operation of selective attention. The threat-capture hypothesis generates two predictions. First, because the threat-detection system directs attention to threat automatically, threat stimuli should capture attention when they are task-irrelevant and the observer has no intention to attend to them. Second, because the threat-detection system operates preattentively, threat stimuli should capture attention even when it is engaged elsewhere. This thesis tested these predictions using behavioural measures of attention capture in conjunction with the N2pc, an event-related potential (ERP) index of attention selection. Experiment 1 tested the first prediction of the threat-capture hypothesis – that threat stimuli capture attention when they are task-irrelevant. Participants performed a dot-probe task in which pairs of face cues – one angry and one neutral – preceded a lateral target. On some trials, the faces were Fourier phase-scrambled to control for low-level visual properties. Consistent with the threat-capture hypothesis, an N2pc was observed for angry faces, suggesting they captured attention despite being completely task-irrelevant. Interestingly, this effect remained when faces were Fourier phase-scrambled, suggesting it is low-level visual properties that drive attention capture by angry faces. Experiments 2A and 2B tested the second prediction of the threat capture hypothesis – that threat stimuli capture attention when it is engaged elsewhere. Participants performed a primary task in which they searched a column of letters at fixation for a target letter. The perceptual load of this task was manipulated to ensure that attentional resources were consumed by this task. Thus there were high and low perceptual load conditions in these experiments. Task-irrelevant angry faces interfered with task performance when the perceptual load of the task was high but not when it was low (Experiment 2A). Similarly, angry faces elicited an N2pc, indicating that they captured attention, but only when perceptual load was high and when faces were phase-scrambled (Experiment 2B). These experiments further suggest that low-level visual factors are important in attention capture by angry faces. These results appear to be inconsistent with the threat-capture hypothesis, and suggest that angry faces do not necessarily capture attention when it is engaged elsewhere.</p>

Attention Capture by Angry Faces Depends on the Distribution of Attention

<p>The threat-capture hypothesis posits a threat-detection system that automatically directs visual attention to threat-related stimuli (e.g., angry facial expressions) in the environment. Importantly, this system is theorised to operate preattentively, processing all input across the visual field in parallel, prior to the operation of selective attention. The threat-capture hypothesis generates two predictions. First, because the threat-detection system directs attention to threat automatically, threat stimuli should capture attention when they are task-irrelevant and the observer has no intention to attend to them. Second, because the threat-detection system operates preattentively, threat stimuli should capture attention even when it is engaged elsewhere. This thesis tested these predictions using behavioural measures of attention capture in conjunction with the N2pc, an event-related potential (ERP) index of attention selection. Experiment 1 tested the first prediction of the threat-capture hypothesis – that threat stimuli capture attention when they are task-irrelevant. Participants performed a dot-probe task in which pairs of face cues – one angry and one neutral – preceded a lateral target. On some trials, the faces were Fourier phase-scrambled to control for low-level visual properties. Consistent with the threat-capture hypothesis, an N2pc was observed for angry faces, suggesting they captured attention despite being completely task-irrelevant. Interestingly, this effect remained when faces were Fourier phase-scrambled, suggesting it is low-level visual properties that drive attention capture by angry faces. Experiments 2A and 2B tested the second prediction of the threat capture hypothesis – that threat stimuli capture attention when it is engaged elsewhere. Participants performed a primary task in which they searched a column of letters at fixation for a target letter. The perceptual load of this task was manipulated to ensure that attentional resources were consumed by this task. Thus there were high and low perceptual load conditions in these experiments. Task-irrelevant angry faces interfered with task performance when the perceptual load of the task was high but not when it was low (Experiment 2A). Similarly, angry faces elicited an N2pc, indicating that they captured attention, but only when perceptual load was high and when faces were phase-scrambled (Experiment 2B). These experiments further suggest that low-level visual factors are important in attention capture by angry faces. These results appear to be inconsistent with the threat-capture hypothesis, and suggest that angry faces do not necessarily capture attention when it is engaged elsewhere.</p>

Attentional Capture From Inside vs. Outside the Attentional Focus

In this study, we jointly reported in an empirical and a theoretical way, for the first time, two main theories: Lavie’s perceptual load theory and Gaspelin et al.’s attentional dwelling hypothesis. These theories explain in different ways the modulation of the perceptual load/task difficulty over attentional capture by irrelevant distractors and lead to the observation of the opposite results with similar manipulations. We hypothesized that these opposite results may critically depend on the distractor type used by the two experimental procedures (i.e., distractors inside vs. outside the attentional focus, which could be, respectively, considered as potentially relevant vs. completely irrelevant to the main task). Across a series of experiments, we compared both theories within the same paradigm by manipulating both the perceptual load/task difficulty and the distractor type. The results were strongly consistent, suggesting that the influence of task demands on attentional capture varies as a function of the distractor type: while the interference from (relevant) distractors presented inside the attentional focus was consistently higher for high vs. low load conditions, there was no modulation by (irrelevant) distractors presented outside the attentional focus. Moreover, we critically analyzed the theoretical conceptualization of interference using both theories, disentangling important outcomes for the dwelling hypothesis. Our results provide specific insights into new aspects of attentional capture, which can critically redefine these two predominant theories.

Visual Perceptual Load Attenuates Age-Related Audiovisual Integration in an Audiovisual Discrimination Task

Previous studies confirmed that the cognitive resources are limited for each person, and perceptual load affects the detection of stimulus greatly; however, how the visual perceptual load influences audiovisual integration (AVI) is still unclear. Here, 20 older and 20 younger adults were recruited to perform an auditory/visual discrimination task under various visual perceptual-load conditions. The analysis for the response times revealed a significantly faster response to the audiovisual stimulus than to the visual stimulus or auditory stimulus (all p &lt; 0.001), and a significantly slower response by the older adults than by the younger adults to all targets (all p ≤ 0.024). The race-model analysis revealed a higher AV facilitation effect for older (12.54%) than for younger (7.08%) adults under low visual perceptual-load conditions; however, no obvious difference was found between younger (2.92%) and older (3.06%) adults under medium visual perceptual-load conditions. Only the AV depression effect was found for both younger and older adults under high visual perceptual-load conditions. Additionally, the peak latencies of AVI were significantly delayed in older adults under all visual perceptual-load conditions. These results suggested that visual perceptual load decreased AVI (i.e., depression effects), and the AVI effect was increased but delayed for older adults.

Is a Preference for Realism Really Naive After All? A Cognitive Model of Learning with Realistic Visualizations

The use of realistic visualizations has gained considerable interest due to the proliferation of virtual reality equipment. This review is concerned with the theoretical basis, technical implementation, cognitive effects, and educational implications of using realistic visualizations. Realism can be useful for learners, but in several studies, more abstract illustrations have resulted in higher performance. Furthermore, a preference for realistic visualization has been declared as being based on misconceptions regarding the cognitive system. However, we argue that this perspective is unable to fully explain the conflicting results found in the literature. To fill this theoretical gap, we devised a model to describe and compare the various levels of realism found in visualizations. We define realism as a combination of three dimensions: geometry, shading, and rendering. By varying these dimensions, it is possible to create a variety of realistic graphics. Thus, when comparing different visualizations, the realism of each of these three dimensions needs to be considered individually. Based on this technical definition, we introduce a cognitive model of learning with realistic visualizations that includes three different stages: perception, schema construction, and testing. At these three stages, variables such as the perceptual load generated by the visualization, learner characteristics influencing how well details are processed, and test types that demand concrete or flexible representations can affect whether realism fosters or hinders learning. Using the cognitive model presented in this paper, more accurate predictions and recommendations concerning the use of realism can be formulated.

Interference of Illusory Contour Perception by a Distractor

The visual system is capable of recognizing objects when object information is widely separated in space, as revealed by the Kanizsa-type illusory contours (ICs). Attentional involvement in perception of ICs is an important topic, and the present study examined whether and how the processing of ICs is interfered with by a distractor. Discrimination between thin and short deformations of an illusory circle was investigated in the absence or presence of a central dynamic patch, with difficulty of discrimination varied in three levels (easy, medium, and hard). Reaction time (RT) was significantly shorter in the absence compared to the presence of the distractor in the easy and medium conditions. Correct rate (CR) was significantly higher in the absence compared to the presence of the distractor in the easy condition, and the magnitude of the difference between CRs of distracted and non-distracted responses significantly reduced as task difficulty increased. These results suggested that perception of ICs is more likely to be vulnerable to distraction when more attentional resources remain available. The present finding supports that attention is engaged in perception of ICs and that distraction of IC processing is associated with perceptual load.

The role of perceptual load and sensory degradation on cross-modal selective attention

To understand our sensory environment, our perceptual system must employ selective attention; the ability to attend to target information while ignoring distracting information. In the uni–modal domain the main determinant of selective attention success is capacity limitation, where only when processing capacity is taxed by the target (high load; HL) is distraction eliminated (perceptual load theory; PLT). Conversely, data limits while also increasing task demands, do not benefit selective attention as these limits are often driven by sensory degradation (SD) such that placing additional resources towards the target is not beneficial. Investigations of PLT to the cross–modal domain have produced mixed results, and no study has yet directly contrasted the impact of capacity and data limits in the cross–modal domain. The present dissertation focused on examining the impact of Perceptual Load (PL) and SD on cross–modal selective attention, in addition to examining how these factors would interact with the attended modality and individual differences (ID) in attentional control. Experiment 1 used a go–no–go manipulation of PL to show that distractor effects were not reduced at HL compared to low load (LL) condition and instead displayed trends for increased distraction under HL regardless of the attended modality. Experiment 2 used the addition of noise to create SD, and found that distractor processing increased under SD, again regardless of the attended modality. Experiment 1 and 2 used a uni–modal measure of attentional control, and overall both studies did not find a consistent pattern of correlation with cross–modal selective attention, suggesting important differences between the two. Experiment 3 used a single manipulation to create HL and SD conditions in a single experiment, and also found that both HL and SD showed trends of increased distraction relative to LL conditions. Overall the current dissertation suggests that capacity limitations arise at the modality level, and so do not impact cross–modal selective attention. As such, the findings of the current dissertation suggest there is no difference between capacity and data limited conditions in the cross–modal domain. Results are interpreted within a cross–modal selective attention framework.