scholarly journals Low level perceptual, not attentional, processes modulate distractor interference in high perceptual Load displays: evidence from neglect patients

2011 ◽  
Vol 11 (11) ◽  
pp. 233-233
Author(s):  
C. Mevorach ◽  
G. Humphreys ◽  
Y. Tsal
2009 ◽  
Vol 20 (11) ◽  
pp. 1388-1393 ◽  
Author(s):  
Anna Remington ◽  
John Swettenham ◽  
Ruth Campbell ◽  
Mike Coleman

It has been suggested that the locus of selective attention (early vs. late in processing) is dependent on the perceptual load of the task. When perceptual load is low, irrelevant distractors are processed (late selection), whereas when perceptual load is high, distractor interference disappears (early selection). Attentional abnormalities have long been reported within autism spectrum disorder (ASD), and this study is the first to examine the effect of perceptual load on selective attention in this population. Fourteen adults with ASD and 23 adults without ASD performed a selective attention task with varying perceptual loads. Compared with the non-ASD group, the ASD group required higher levels of perceptual load to successfully ignore irrelevant distractors; moreover, the ASD group did not show any general reduction in performance speed or accuracy. These results suggest enhanced perceptual capacity in the ASD group and are consistent with previous observations regarding superior visual search abilities among individuals with ASD.


2021 ◽  
Author(s):  
◽  
Joshua James Foster

<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>


2018 ◽  
Author(s):  
Amelie Reynaud ◽  
Mathilda Froesel ◽  
Carole Guedj ◽  
Sameh Ben Hadj Hassen ◽  
Justine Clery ◽  
...  

The role of norepinephrine (NE) in visuo-spatial attention remains poorly understood. Our goal was to identify the attentional processes under the influence of NE and to characterize these influences. We tested the effects of atomoxetine injections (ATX), a NE-reuptake inhibitor that boosts the level of NE in the brain, on seven monkeys performing a saccadic cued task in which cues and distractors were used to manipulate spatial attention. We found that when the cue accurately predicted the location of the upcoming cue in 80% of the trials, ATX consistently improved attentional orienting, as measured from reaction times (RTs). These effects were best accounted for by a faster accumulation rate in the valid trials, rather than by a change in the decision threshold. By contrast, the effect of ATX on alerting and distractor interference was more mitigated. Finally, we also found that, under ATX, RTs to non-cued targets were longer when these were presented separately from cued targets. This suggests that the impact of NE on visuo-spatial attention depends on the context, such that the adaptive changes elicited by the highly informative value of the cues in the most frequent trials were accompanied by a cost in the less frequent trials.


2018 ◽  
Author(s):  
Sebastian Schindler ◽  
Antonio Schettino ◽  
Gilles Pourtois

Processing affectively charged visual stimuli typically results in increased amplitude of specific event-related potential (ERP) components. Low-level features similarly modulate electrophysiological responses, with amplitude changes proportional to variations in stimulus size and contrast. However, it remains unclear whether emotion-related amplifications during visual word processing are necessarily intertwined with changes in specific low-level features or, instead, may act independently.In this pre-registered electrophysiological study, we varied font size and contrast of neutral and negative words while participants were monitoring their semantic content. We examined ERP responses associated with early sensory and attentional processes as well as later stages of stimulus processing. Results showed amplitude modulations by low-level visual features early on following stimulus onset – i.e., P1 and N1 components –, while the LPP was independently modulated by these visual features. Independent effects of size and emotion were observed only at the level of the EPN. Here, larger EPN amplitudes for negative were observed only for small high contrast and large low contrast words. These results suggest that early increase in sensory processing at the EPN level for negative words is not automatic, but bound to specific combinations of low-level features, occurring presumably via attentional control processes.


2019 ◽  
Author(s):  
Sebastian Schindler ◽  
Maximilian Bruchmann ◽  
Bettina Gathmann ◽  
robert.moeck ◽  
thomas straube

Emotional facial expressions lead to modulations of early event-related potentials (ERPs). However, it has so far remained unclear in how far these modulations represent face-specific effects rather than differences in low-level visual features, and to which extent they depend on available processing resources. To examine these questions, we conducted two preregistered independent experiments (N = 40 in each experiment) using different variants of a novel task which manipulates peripheral perceptual load across levels but keeps overall visual stimulation constant. Centrally, task-irrelevant angry, neutral and happy faces and their Fourier phase-scrambled versions, which preserved low-level visual features, were presented. The results of both studies showed load-independent P1 and N170 emotion effects. Importantly, we could confirm by using Bayesian analyses that these emotion effects were face-independent for the P1 but not for the N170 component. We conclude that firstly, ERP modulations during the P1 interval strongly depend on low-level visual information, while the emotional N170 modulation requires the processing of figural facial features. Secondly, both P1 and N170 modulations appear to be immune to a large range of variations in perceptual load.


2021 ◽  
pp. 174702182110688
Author(s):  
Hasan Gunduz ◽  
Turan Gunduz ◽  
Arzu Ozkan Ceylan

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.


2012 ◽  
Vol 65 (4) ◽  
pp. 617-623 ◽  
Author(s):  
Hirotsune Sato ◽  
Ippei Takenaka ◽  
Jun I. Kawahara

PLoS ONE ◽  
2022 ◽  
Vol 17 (1) ◽  
pp. e0258832
Author(s):  
Jonathan C. Flavell ◽  
Harriet Over ◽  
Tim Vestner ◽  
Richard Cook ◽  
Steven P. Tipper

Using visual search displays of interacting and non-interacting pairs, it has been demonstrated that detection of social interactions is facilitated. For example, two people facing each other are found faster than two people with their backs turned: an effect that may reflect social binding. However, recent work has shown the same effects with non-social arrow stimuli, where towards facing arrows are detected faster than away facing arrows. This latter work suggests a primary mechanism is an attention orienting process driven by basic low-level direction cues. However, evidence for lower level attentional processes does not preclude a potential additional role of higher-level social processes. Therefore, in this series of experiments we test this idea further by directly comparing basic visual features that orient attention with representations of socially interacting individuals. Results confirm the potency of orienting of attention via low-level visual features in the detection of interacting objects. In contrast, there is little evidence for the representation of social interactions influencing initial search performance.


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