Perceptual Load Research Articles

Robust perceptual-load-dependent audiovisual integration in adult ADHD

We perceive our daily-life surrounded by different senses (e.g., visual, and auditory). For a coherent percept, our brain binds those multiple streams of sensory stimulations, i.e., multisensory integration (MI). Dependent on stimulus complexity, early MI is triggered by bottom–up or late via top–down attentional deployment. Adult attention-deficit/hyperactivity disorder (ADHD) is associated with successful bottom–up MI and deficient top–down MI. In the current study, we investigated the robustness of the bottom–up MI by adding additional task demand varying the perceptual load. We hypothesized diminished bottom–up MI for high perceptual load for patients with ADHD. 18 adult patients with ADHD and 18 age- and gender-matched healthy controls participated in this study. In the visual search paradigm, a target letter was surrounded by uniform distractors (low load) or by different letters (high load). Additionally, either unimodal (visual flash, auditory beep) or multimodal (audiovisual) flanked the visual search. Linear-mixed modeling was used to investigate the influence of load on reaction times. Further, the race model inequality was calculated. Patients with ADHD showed a similar degree of MI performance like healthy controls, irrespective of perceptual load manipulation. ADHD patients violated the race model for the low load but not for the high-load condition. There seems to be robust bottom–up MI independent of perceptual load in ADHD patients. However, the sensory accumulation might be altered when attentional demands are high.

The mechanisms of far transfer from cognitive training: specifying the role of distraction suppression.

Cognitive training aims to produce a durable transfer to untrained abilities (i.e., far transfer). However, designing effective programs is difficult, because far transfer mechanisms are not well understood. Greenwood and Parasuraman (Neuropsychol 30(6):742-755. https://doi.org/10.1037/neu0000235 , 2016) proposed that the ability to ignore distractions is key in promoting far transfer. While the authors identified working-memory training based on the N-back task as an effective way to train distraction suppression, a recent meta-analysis concluded that this form of training rarely produces far transfer. Such inconsistency casts doubt onto the importance of distraction suppression in far transfer and calls for further examination of the role of this ability in cognitive training effectiveness. We propose here to conceptualize distraction suppression in the light of the load theory of attention, which distinguishes two mechanisms of distractor rejection depending on the level and type of information load involved: perceptual selection and cognitive control. From that standpoint, N-back training engages a single suppression mechanism, namely cognitive control, because it mainly involves low perceptual load. In the present study, we compared the efficacy of N-back training in producing far transfer to that of a new response-competition training paradigm that solicits both distraction suppression mechanisms. Response-competition training was the only one to produce far transfer effects relative to an active control training. These findings provided further support to Greenwood and Parasuraman's hypothesis and suggest that both selection perception and cognitive control need to be engaged during training to increase the ability to suppress distraction, hence to promote far transfer.

Heart's eyes to see color: Cardiac vagal tone modulates the impact of ethnicity on selected attention under high load

The present study tested whether cardiac vagal activity—which is known to play a vital role in social cognition and engagement—predicted the impact of faces of other ethnicity on selective attention under load. Based on the neurovisceral integration theory, we hypothesized that participants with higher resting heart rate variability (HRV) would exhibit better task performance of a target detection task in trials with face distractors of other ethnicity than participants with lower resting HRV, when cognitive resources were scarce under high load. Caucasian participants were instructed to detect a target letter among letter strings superimposed on Black or White male distractor faces under high and low perceptual load. Consistent with the prediction, under high load, HRV was positively correlated with accuracy in trials with Black distractor faces, but not in trials with White distractor faces. The current research demonstrated that individual differences in cardiac vagal tone predicted successful inhibition of an ethnicity-related distractor with limited cognitive resources, which allowed for completing goal-directed behavior more successfully.

Virtual reality-based distraction on pain, performance, and anxiety during and after moderate-vigorous intensity cycling

Purpose: To determine whether increased visual perceptual load (PL) within an immersive virtual environment may help explain previously shown pain-relieving effects of virtual reality (VR) during high intensity cycling.Methods: Using a within-subjects design, participants cycled at a perceptually “hard” intensity for 10 min on three separate occasions. The first session did not use VR (i.e., no perceptual load - NPL). Subsequent sessions employed VR during cycling with either a low or high perceptual load (LPL or HPL). Quadriceps pain intensity (PI) was reported by participants throughout cycling.Results: Data were analyzed for 43 healthy participants (20 females, mean age 21 [SD 1.4]). For PI, ANOVA showed there were significant main effects of condition (F = 13.458, df =1.579, 66.334, p<0.001) and time (F = 113.045, df =1.618, 227.683, p<0.001). At every time point, t-tests revealed mean PI was significantly lower in the NPL than in the LPL condition (t(42)=4.737, p<0.001, d = 0.472) and HPL condition (t(42)=3.380, p = 0.002, d = 0.391). Dependent t-tests showed that more work (kilojoules) was performed during the LPL condition than the NPL (t(42)=2.992, p = 0.005) and HPL (t(42)=5.810, p<0.001) conditions.Conclusions: Compared to a traditional 10-minute bout of cycle ergometry (NPL), individuals who cycled in the LPL condition chose to exercise at a higher intensity despite greater PI. Those who cycled in the HPL condition did not change their exercise intensity, but did report higher PI, possibly, because of the greater mental effort/energy requirement.

Is action understanding an automatic process? Both cognitive and perceptual processing are required for the identification of actions and intentions.

The ability to identify others' actions and intentions, "action understanding," is crucial for successful social interaction. Under direct accounts, action understanding takes place without the involvement of inferential processes, a claim that has yet to be tested using behavioural measures. Using a dual-task paradigm, the present study aimed to establish whether the identification of others' actions and intentions depends on automatic or inferential processing, by manipulating working memory load during performance of a task designed to target the identification of actions and intentions. Experiment 1 tested a novel action understanding task targeting action identification and intention identification. This task was then combined with two working memory manipulations (cognitive: Experiment 2; perceptual: Experiment 3) to determine whether action identification and intention identification are disrupted by concurrent cognitive or perceptual load. Both action identification and intention identification were impaired by concurrent cognitive and perceptual processing, indicating that action understanding requires additional perceptual and cognitive resources. These findings contradict a direct account of action understanding.

Quality of experience of 360 video \u2013 subjective and eye-tracking assessment of encoding and freezing distortions

The research domain on the Quality of Experience (QoE) of 2D video streaming has been well established. However, a new video format is emerging and gaining popularity and availability: VR 360-degree video. The processing and transmission of 360-degree videos brings along new challenges such as large bandwidth requirements and the occurrence of different distortions. The viewing experience is also substantially different from 2D video, it offers more interactive freedom on the viewing angle but can also be more demanding and cause cybersickness. The first goal of this article is to complement earlier research by Tran, et al. (2017) [39] testing the effects of quality degradation, freezing, and content on the QoE of 360-videos. The second goal is to test the contribution of visual attention as an influence factor in the QoE assessment. Data was gathered through subjective tests where participants watched degraded versions of 360-videos through a Head-Mounted Display with integrated eye-tracking sensors. After each video they answered questions regarding their quality perception, experience, perceptual load, and cybersickness. Our results showed that the participants rated the overall QoE rather low, and the ratings decreased with added degradations and freezing events. Cyber sickness was found not to be an issue. The effects of the manipulations on visual attention were minimal. Attention was mainly directed by content, but also by surprising elements. The addition of eye-tracking metrics did not further explain individual differences in subjective ratings. Nevertheless, it was found that looking at moving objects increased the negative effect of freezing events and made participants less sensitive to quality distortions. More research is needed to conclude whether visual attention is an influence factor on the QoE in 360-video.

Effects of Temporal Characteristics on Pilots Perceiving Audiovisual Warning Signals Under Different Perceptual Loads.

Our research aimed to investigate the effectiveness of auditory, visual, and audiovisual warning signals for capturing the attention of the pilot, and how stimulus onset asynchronies (SOA) in audiovisual stimuli affect pilots perceiving the bimodal warning signals under different perceptual load conditions. In experiment 1 of the low perceptual load condition, participants discriminated the location (right vs. left) of visual targets preceded by five different types of warning signals. In experiment 2 of high perceptual load, participants completed the location task identical to a low load condition and a digit detection task in a rapid serial visual presentation (RSVP) stream. The main effect of warning signals in two experiments showed that visual and auditory cues presented simultaneously (AV) could effectively and efficiently arouse the attention of the pilots in high and low load conditions. Specifically, auditory (A), AV, and visual preceding auditory stimulus by 100 ms (VA100) increased the spatial orientation to a valid position in low load conditions. With the increase in visual perceptual load, auditory preceding the visual stimulus by 100 ms (AV100) and A warning signals had stronger spatial orientation. The results are expected to theoretically support the optimization design of the cockpit display interface, contributing to immediate flight crew awareness.

Assessing Perceptual Load and Cognitive Load by Fixation-Related Information of Eye Movements.

Assessing mental workload is imperative for avoiding unintended negative consequences in critical situations such as driving and piloting. To evaluate mental workload, measures of eye movements have been adopted, but unequivocal results remain elusive, especially those related to fixation-related parameters. We aimed to resolve the discrepancy of previous results by differentiating two kinds of mental workload (perceptual load and cognitive load) and manipulated them independently using a modified video game. We found opposite effects of the two kinds of mental workload on fixation-related parameters: shorter fixation durations and more fixations when participants played an episode with high (vs. low) perceptual load, and longer fixation durations and fewer fixations when they played an episode with high (vs. low) cognitive load. Such opposite effects were in line with the load theory and demonstrated that fixation-related parameters can be used to index mental workload at different (perceptual and cognitive) stages of mental processing.

Attentional control and metacognitive monitoring of the effects of different types of task-irrelevant sound on serial recall.

The presence of task-irrelevant sound disrupts short-term memory for serial information. Recent studies found that enhanced perceptual task-encoding load (static visual noise added to target items) reduces the disruptive effect of an auditory deviant but does not affect the task-specific interference by changing-state sound, indicating that the deviation effect may be more susceptible to attentional control. This study aimed to further specify the role of attentional control in shielding against different types of auditory distraction, examining speech and nonspeech distractors presented in laboratory and Web based experiments. To further elucidate the role of controlled processes, we tested whether the detrimental effects of distractor sounds-and their modulation by attentional control-reach participants' awareness. We found that changing-state sound and auditory deviants in steady-state sound equally affected both objective recall performance and metacognitive confidence judgments but did not affect the accuracy of confidence judgments. Most importantly, across four experiments, an increase of task load (visual degradation of the to-be-remembered items) did not reduce either type of auditory distraction. A close replication of the original modulation of the deviation effect by perceptual task load (in an online environment) even revealed a stronger deviation effect at high task load, suggesting that the manipulation may have influenced cognitive load and the ability to control distractor interference in memory. In line with a unitary account of auditory distraction, the results suggest that although both types of distraction reach metacognitive awareness, they may be equally unrelated to perceptual load and the availability of attentional resources. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Attention mechanisms underlying dual-color digital visual search based on Schulte grid: An event-related potential study.

BackgroundAttention selection is considered to be determined by the perceptual load of cognitive tasks and attention resources that are assigned to processing‐independent stimuli.MethodsUsing visual search paradigm and Schulte grid, the behavioral responses and event‐related potential (ERP) of 27 pupils aged 8–11 (12 girls and 15 boys) were recorded. The subjects were asked to search for the numbers 1, 2, and 3 sequentially and locate the number 5 in the case of monochromatic (black) and bicolor (black‐red) numbers.ResultsWe found that the sequential search task took longer than the location search task (p < .05). Furthermore, both search tasks took longer in two‐color conditions than in monochromatic conditions. However, as for sequential search and location search tasks, no significant intra‐group difference was found. ERP data showed that there was significant difference between monochromatic and bichromatic conditions in locating search tasks (P2–P4: p < .05; T7: p < .05, T8: p < .05), but there was no significant difference in sequential search tasks.ConclusionsOur results indicates that red will be interfered when searching for one number, but will not be interfered when searching for three numbers, which is related to the higher perceptual load of sequential search tasks and less attention resources than those used to interfere with stimulus processing.

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 behaviour 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. The 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. The 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.

The role of perceptual and cognitive load on inattentional blindness: A systematic review and three meta-analyses.

The inattentional blindness phenomenon refers to situations in which a visible but unexpected stimulus remains consciously unnoticed by observers. This phenomenon is classically explained as the consequence of insufficient attention, because attentional resources are already engaged elsewhere or vary between individuals. However, this attentional-resources view is broad and often imprecise regarding the variety of attentional models, the different pools of resources that can be involved in attentional tasks, and the heterogeneity of the experimental paradigms. Our aim was to investigate whether a classic theoretical model of attention, namely the Load Theory, could account for a large range of empirical findings in this field by distinguishing the role of perceptual and cognitive resources in attentional selection and attentional capture by irrelevant stimuli. As this model has been mostly built on implicit measures of distractor interference, it is unclear whether its predictions also hold when explicit and subjective awareness of an unexpected stimulus is concerned. Therefore, we conducted a systematic review and meta-analyses of inattentional blindness studies investigating the role of perceptual and/or cognitive resources. The results reveal that, in line with the perceptual account of the Load Theory, inattentional blindness significantly increases with the perceptual load of the task. However, the cognitive account of this theory is not clearly supported by the empirical findings analysed here. Furthermore, the interaction between perceptual and cognitive load on inattentional blindness remains understudied. Theoretical implications for the Load Theory are discussed, notably regarding the difference between attentional capture and subjective awareness paradigms, and further research directions are provided.

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.

Anterior cingulate cortex activation during attentional control as a transdiagnostic marker of psychotherapy response: a randomized clinical trial.

Anterior cingulate cortex (ACC) response during attentional control in the context of task-irrelevant emotional faces is a promising biomarker of cognitive behavioral therapy (CBT) outcome in patients with social anxiety disorder (SAD). However, it is unclear whether this biomarker extends to major depressive disorder (MDD) and is specific to CBT outcome. In the current study, 72 unmedicated patients with SAD (n = 39) or MDD (n = 33) completed a validated emotional interference paradigm during functional magnetic resonance imaging before treatment. Participants viewed letter strings superimposed on task-irrelevant threat and neutral faces under low perceptual load (high interference) and high perceptual load (low interference). Biomarkers comprised anatomy-based rostral ACC (rACC) and dorsal ACC (dACC) response to task-irrelevant threat (>neutral) faces under low and high perceptual load. Patients were randomly assigned to 12 weeks of CBT or supportive therapy (ST) (ClinicalTrials.gov identifier: NCT03175068). Clinician-administered measures of social anxiety and depression severity were obtained at baseline and every 2 weeks throughout treatment (7 assessments total) by an assessor blinded to the treatment arm. A composite symptom severity score was submitted to latent growth curve models. Results showed more baseline rACC activity to task-irrelevant threat>neutral faces under low, but not high, perceptual load predicted steeper trajectories of symptom improvement throughout CBT or ST. Post-hoc analyses indicated this effect was driven by subgenual ACC (sgACC) activation. Findings indicate ACC activity during attentional control may be a transdiagnostic neural predictor of general psychotherapy outcome.

The impact of auditory distraction on reading comprehension: An individual differences investigation.

Background noise disrupts auditory selective attention and impairs performance on cognitive tasks, but the degree to which it is disruptive depends on the task and the individual. According to the load theory of attention and cognitive control, selective attention is influenced by both the perceptual load and the cognitive load of the primary task. Recent studies suggest that hard-to-read font in a reading task may shield attention against background noise and auditory distraction. The current study examined the disruptive effect of background noise on reading comprehension as a function of perceptual load and cognitive load. Perceptual load was manipulated by introducing task disfluency (hard-to-read or easy-to-read font), and cognitive load was manipulated by varying the type of background noise and investigating individual differences in working memory capacity. The results suggest that high perceptual load and high working memory capacity both facilitate reading comprehension. However, contrary to previous research, neither perceptual load nor capacity moderates the disruptive effect of background noise. These results failed to support the generalizability and applicability of the shield effect of perceptual disfluency against auditory distraction during reading but supported the beneficial effect of perceptual disfluency on reading comprehension.

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 < 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

Abstract 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.

Spatial Attention Modulated by Perceptual Load: Behavioral and Electrophysiological Evidence

Spatial Attention Modulated by Perceptual Load: Behavioral and Electrophysiological Evidence

Anterior cingulate cortex activity during attentional control corresponds with rumination in depression and social anxiety

Rumination and worry are transdiagnostic perseverative cognitions that have overlapping and distinct characteristics. While the mechanisms of perseverative cognitions remain incomplete, limited data indicate anterior cingulate cortex (ACC) as it relates to top-down functions contributes to perseverative cognitions in internalizing conditions. The current study extends this work in patients with major depression (n = 39) or social anxiety (n = 42). During fMRI, participants viewed images comprising letter strings superimposed on task-irrelevant threatening or neutral faces. To moderate task difficulty, there was a low perceptual load condition where the target letter was in a string of identical letters and high load condition with the target letter in a mixed letter string increasing task difficulty. Regions of interest (ROI) comprised dorsal ACC and rostral ACC. Bilateral amygdala was also examined. Results showed diagnostic groups had similar levels of rumination and worry. Exploratory hierarchical regression analysis comprising clinical measures, task performance, and the 4 ROIs revealed significantly less dorsal ACC engagement during low (vs. high) load to task-irrelevant faces corresponded with more rumination, but not worry, regardless of diagnostic status. However, the ACC finding did not survive Bonferroni correction. Preliminary results suggest dorsal ACC response during attentional control may serve as a transdiagnostic mechanism of rumination.

Faces are not always special for attention: Effects of response–relevance and identity

Research over the past 25 years indicates that stimulus processing is diminished when attention is engaged in a perceptually demanding task of high ‘perceptual load’. These results have generalized across a variety of stimulus categories, but a controversy evolved over the question of whether perception of distractor faces (or other categories of perceptual expertise) can proceed irrespective of the level of perceptual load in the attended task. Here we identify task-relevance, and in particular identity-relevance, as a potentially important factor in explaining prior inconsistencies. In four experiments, we tested whether perceptual load in an attended letter or word task modulates the processing of famous face distractors, while varying their task-relevance. Distractor interference effects on task RTs was reduced by perceptual load not only when the faces were entirely task-irrelevant, but also when the face gender was task relevant, within a name gender classification response-competition task, using famous female or male distractor faces. However, when the identity associated with the famous faces was primed by the task using their names, as in prior demonstrations that face distractors are immune to the effects of perceptual load, we were able to replicate these prior findings. Our findings demonstrate a role for identity-priming by the relevant task in determining attentional capture by faces under high perceptual load. Our results also highlight the importance of considering even relatively subtle forms of task-relevance in selective attention research.