Perceptual Load Research Articles

Prefrontal control and predictors of cognitive behavioral therapy response in social anxiety disorder.

Generalized social anxiety disorder (gSAD) is associated with aberrant anterior cingulate cortex (ACC) response to threat distractors. Perceptual load has been shown to modulate ACC activity such that under high load, when demands on processing capacity is restricted, individuals with gSAD exhibit compensatory activation to threat distractors yet under low load, there is evidence of reduced activation. It is not known if neural predictors of response to cognitive behavioral therapy (CBT), based on such emotional conflict resolution, interact with demands on controlled processes. Prior to CBT, 32 patients with gSAD completed an fMRI task involving a target letter in a string of identical targets (low perceptual load) or a target letter in a mixed letter string (high perceptual load) superimposed on fearful, angry and neutral face distractors. Whole-brain voxel-wise analyses revealed better CBT outcome was predicted by more frontopartial activity that included dorsal ACC (dACC) and insula to threat (vs neutral) distractors during high, but not low, perceptual load. Psychophysiological interaction analysis with dACC as the seed region revealed less connectivity with dorsolateral prefrontal cortex to threat distractors during high load. Results indicate patients with less regulatory capability when demands on higher-order control are great may benefit more from CBT.

Beating their chests: University students with ADHD demonstrate greater attentional abilities on an inattentional blindness paradigm.

Adults diagnosed with attentional deficit disorder (ADHD) are easily distracted in many tasks. Yet ADHD performance on inattentional blindness (IB) tasks has not been examined. Such investigation may aid in discriminating between 3 ADHD models: the neurological model, the perceptual load theory, and the "hunter versus farmer" hypothesis. Distractibility was assessed in ADHD and non-ADHD college students using the MOXO task that involves detection of a single attended stimulus that repeatedly appears in the same place and in the well-known IB "gorilla" video which involves tracking of a stimulus moving at a fast pace in a dynamic, complex manner. ADHD college students showed increased distractibility in the MOXO task. By contrast, they performed better than controls in the attended channel of the IB task, while they were also better at noticing the unattended stimuli and thus exhibiting little-to-no inattentional blindness. As no attentional tradeoffs were evident in the IB task, it appears that the results are most consistent with the "hunter versus farmer" hypothesis, which postulates that ADHD individuals have an alternative cognitive style which is less equipped to deal with detection of repeated stimuli while comprising advantages in the tracking of stimuli moving in a fast dynamic manner.

Effect of mind wandering and perceptual load on attentional capture quantity

Effect of mind wandering and perceptual load on attentional capture quantity

Is object-based attention-spreading prevented by perceptual load?

Is object-based attention-spreading prevented by perceptual load?

Effects of perceptual load in visual search in immersive virtual reality

Research using computerized displays of simple stimuli has identified perceptual load as a critical factor for modulating distraction. Distraction is stronger when perceptual load is low than when it is high. Typically, participants determine which of two targets, e.g., letters, is present in a search array composed of other letters and perceptual load of the displays is varied. In the present experiment we made contact with the literature but increased ecological validity by assessing distraction in immersive Virtual Reality (VR), in which life-sized stimuli can be displayed in realistic settings, without losing the advantage of controlling conditions. Participants searched for a target (soda or yoghurt) among other daily objects on the countertop in a virtual kitchen. The search array was accompanied by a congruent or incongruent flanker. Perceptual load was manipulated. As expected, participants responded slower with incongruent flankers (flanker effect) and with high load (load effect), confirming that our materials and set up in the VR environment were suitable to elicit the basic effects. Contrary to our expectations based on the load theory of attention the flanker effect was not modulated by load. This finding may suggest that perceptual load may play a smaller role in attention and search in everyday situations than one would assume based on previous work. Obviously, virtual scenarios are more complex than the stimuli used and the conditions run in previous studies. Further, it is possible that daily, very familiar objects may be harder to ignore or be prioritized for processing also under high perceptual load. We discuss factors that may dilute or negate effects of perceptual load in a more ecologically valid situation and outline suggestions for further research. We suggest that VR offers an exciting interdisciplinary approach that may challenge our beliefs based on traditional laboratory research. Meeting abstract presented at VSS 2015. Language: en

Simulated Driving Environment Impacts Mind Wandering

Mind wandering, when attention is internally engaged on task-unrelated thoughts, is potentially hazardous for driving. Understanding the factors that influence the frequency of mind wandering during driving is important, but remains unclear. This study investigated the effect of perceptual load on the rate and cost of mind wandering during driving. Perceptual load was varied in simulated driving by controlling the amount of presentation of traffic, intersections and buildings along the drive. We found a higher frequency of mind wandering in the lower perceptual load condition when a plain drive with no traffic, intersections or buildings were presented. Impacts of mind wandering on driving were found in reaction time, with task-unrelated thought having a longer time to respond.

Perceptual load of divided attention modulates auditory-motor integration of voice control

The present study sought to examine how the auditory-motor processing of feedback errors during vocal pitch regulation is modulated as a function of divided attention. Subjects were exposed to pitch perturbations in voice auditory feedback and flashing lights on the computer screen, during which they were asked to divide their attention to both auditory and visual stimuli by counting the number of both of them. The presentation rate of the visual stimuli (inter-stimulus intervel) was manipulated to produce a low, intermediate, and high attentional load. The results revealed that, as compared to the low and intermediate attentional load conditions, the high attentional load condition elicited significantly smaller magnitudes of vocal responses but larger amplitudes of N1 and P2 responses to pitch feedback perturbations. These findings demonstrate the effect of attentional load on the auditory-motor processing of pitch feedback errors during divided attention, suggesting that perceptual load of visual attention interferes the attentional modulation of auditory-motor integration in voice control.

Social Groups Prioritize Selective Attention to Faces: How Social Identity Shapes Distractor Interference

Extensive research suggests that faces might inevitably capture visual attention. In two experiments, we examined how social groups guide selective attention toward in-group and out-group faces. Black and White participants detected a target letter among letter strings superimposed on faces (Experiment 1). White participants were less accurate on trials with out-group (Black) compared to in-group (White) distractor faces. Likewise, Black participants were less accurate on trials with out-group (White) compared to in-group (Black) distractor faces. However, this pattern of out-group bias was only evident under high perceptual load — when the task was visually difficult. To examine the malleability of this pattern of racial bias, participants were assigned to mixed-race minimal groups (Experiment 2). Participants assigned to groups were less accurate on trials with their minimal in-group members compared to minimal out-group distractor faces under high load, regardless of race. The current research suggests that social identity guides selective attention toward motivationally relevant social groups — shifting from out-group bias in the domain of race to in-group bias in the domain of minimal groups — when perceptual resources are scarce.

A functional magnetic resonance imaging study of cognitive control and neurosensory deficits in mild traumatic brain injury.

Mild traumatic brain injury patients (mTBI) frequently report symptoms of increased distractability and sensory disturbances during mutisensory stimulation. These common post-concussive symptoms could putatively result from dysfunction within the cognitive control network (CCN; top-down) or from unisensory cortex (bottom-up) itself. Functional magnetic resonance imaging (fMRI) and high-resolution structural data were therefore prospectively collected during a multisensory (audio-visual) cognitive control task from 46 mTBI patients within 3 weeks of injury and 46 matched healthy controls (HC), with a subset of participants returning at 4 months. Multisensory stimuli were presented at two frequencies to manipulate cognitive and perceptual load. Patients self-reported more cognitive, emotional, somatic, vestibular and visual symptoms relative to HC, which improved, but did not entirely resolve, over the 4 month follow-up period. There were no group differences in behavior or functional activation during cognitive control (incongruent--congruent trials). In contrast, patients exhibited abnormal activation within different regions of visual cortex that depended on whether attention was focused on auditory or visual information streams. Patients also exhibited increased activation within bilateral inferior parietal lobules during higher cognitive/perceptual loads, suggesting a compensatory mechanism to achieve similar levels of behavioral performance. Functional abnormalities within the visual cortex and inferior parietal lobules were only partially resolved at 4 months post-injury, suggesting that neural abnormalities may take longer to resolve than behavioral measures used in most clinical settings. In summary, current results indicate that abnormalities within unisensory cortex (particularly visual areas) following mTBI, which likely contribute to deficits commonly reported during multisensory stimulation.

High perceptual load causes inattentional blindness and deafness in drivers

ABSTRACTPerceptual load theory of attention predicts that the level of perceptual load in a primary task affects the processing of additional stimuli. Given the lack of ecologically valid evidence for the model, the current study assessed the effect of perceptual load on driver awareness during simulated driving tasks. The results showed that perceptual load dramatically affected driver awareness for visual and auditory stimuli, even those that were driving relevant and safety critical (e.g. pedestrians or the sound of a car horn). The results support load theory and suggest that perceptual load may be an important factor in driver safety.

Efficient human face detection in infancy.

Adults detect conspecific faces more efficiently than heterospecific faces; however, the development of this own-species bias (OSB) remains unexplored. We tested whether 6- and 11-month-olds exhibit OSB in their attention to human and animal faces in complex visual displays with high perceptual load (25 images competing for attention). Infants (n = 48) and adults (n = 43) passively viewed arrays containing a face among 24 non-face distractors while we measured their gaze with remote eye tracking. While OSB is typically not observed until about 9 months, we found that, already by 6 months, human faces were more likely to be detected, were detected more quickly (attention capture), and received longer looks (attention holding) than animal faces. These data suggest that 6-month-olds already exhibit OSB in face detection efficiency, consistent with perceptual attunement. This specialization may reflect the biological importance of detecting conspecific faces, a foundational ability for early social interactions.

Linking inter-individual differences in the perceptual load effect to spontaneous brain activity.

Previous researches have widely demonstrated that the interference from peripheral distractor will decrease when the task load is high. However, no study to date has paid attention to the individual differences in perceptual load effect (PLE) and little is known of spontaneous brain activity associated with PLE during resting state. To investigate this issue, we used resting-state functional Magnetic Resonance Imaging (fMRI) to examine the relationship between the amplitude of low-frequency fluctuations (ALFFs) and PLE. The results showed that there were large individual differences in PLE and we found PLE was significantly associated with ALFFs in left inferior temporal gyrus (ITG) and left precentral/postcentral gyrus. The present study suggested that the PLE was measurable, and there were individual differences in this effect. Moreover, these results implicated that: 1) mutual competition for limited capacity, which is involved in visual attention, and 2) response control that is included in behavior response both may contribute to the modulation induced by perceptual load.

Interactions Between Modality of Working Memory Load and Perceptual Load in Distractor Processing

ABSTRACTThe present study investigated interactions between working memory load and perceptual load. The load theory (Lavie, Hirst, de Fockert, & Viding, 2004) claims that perceptual load decreases distractor interference, whereas working memory load increases interference. However, recent studies showed that effects of working memory might depend on the relationship between modalities of working memory and task stimuli. Here, we examined whether the relationship between working memory load and perceptual load would remain the same across modalities. The results of Experiment 1 showed that verbal working memory load did not affect a compatibility effect for low perceptual load, whereas it increased the compatibility effect for high perceptual load. In Experiment 2, the compatibility effect remained the same regardless of visual working memory load. These results suggest that the effects of working memory load and perceptual load depend on the relationship between the modalities of working memory and stimuli.

Distinct load effects by set-size and target-distractor similarity in visual search

Using the simultaneous-sequential presentation search paradigm, we investigated how different types of load manipulation would tap into attentional resources and the concrete mechanism by which search would be performed. Search display perceptual load was manipulated by set-size and target-distractor similarity. The benefit of sequential presentation was larger when the load was increased by number of search items than when target-distractor discrimination was made more demanding. Considering that the load effect could be result from both perceptual load and statistical decision noise, the current results are explained by suggesting that set-size will determine whether the search process will be serial or parallel, regardless of perceptual difficulty. Factors that can set the limit of attentional resources are also discussed.

The Competitive Influences of Perceptual Load and Working Memory Guidance on Selective Attention.

The perceptual load theory in selective attention literature proposes that the interference from task-irrelevant distractor is eliminated when perceptual capacity is fully consumed by task-relevant information. However, the biased competition model suggests that the contents of working memory (WM) can guide attentional selection automatically, even when this guidance is detrimental to visual search. An intriguing but unsolved question is what will happen when selective attention is influenced by both perceptual load and WM guidance. To study this issue, behavioral performances and event-related potentials (ERPs) were recorded when participants were presented with a cue to either identify or hold in memory and had to perform a visual search task subsequently, under conditions of low or high perceptual load. Behavioural data showed that high perceptual load eliminated the attentional capture by WM. The ERP results revealed an obvious WM guidance effect in P1 component with invalid trials eliciting larger P1 than neutral trials, regardless of the level of perceptual load. The interaction between perceptual load and WM guidance was significant for the posterior N1 component. The memory guidance effect on N1 was eliminated by high perceptual load. Standardized Low Resolution Electrical Tomography Analysis (sLORETA) showed that the WM guidance effect and the perceptual load effect on attention can be localized into the occipital area and parietal lobe, respectively. Merely identifying the cue produced no effect on the P1 or N1 component. These results suggest that in selective attention, the information held in WM could capture attention at the early stage of visual processing in the occipital cortex. Interestingly, this initial capture of attention by WM could be modulated by the level of perceptual load and the parietal lobe mediates target selection at the discrimination stage.

The effect of visual perceptual load on auditory awareness in autism spectrum disorder.

Recent work on visual selective attention has shown that individuals with Autism Spectrum Disorder (ASD) demonstrate an increased perceptual capacity. The current study examined whether increasing visual perceptual load also has less of an effect on auditory awareness in children with ASD. Participants performed either a high- or low load version of a line discrimination task. On a critical trial, an unexpected, task-irrelevant auditory stimulus was played concurrently with the visual stimulus. In contrast to typically developing (TD) children, children with ASD demonstrated similar detection rates across perceptual load conditions, and reported greater awareness than TD children in the high perceptual load condition. These findings suggest an increased perceptual capacity in children with ASD that operates across sensory modalities.

FEATURES OF PERCEPTION OF LOADING ELEMENTS OF THE RAILWAY TRACK AT HIGH SPEEDS OF THE MOVEMENT

Purpose. Increase the train speeds movements requires not only the appropriate technical solutions, but also methodological-calculated. Most of the models and methodologies used for solving problems of stress-strain state of the railroad tracks, are based on assumptions and hypotheses adequate only for certain speeds. In the framework of this work will be discussed theoretical background of the changing nature of perceptual load elements of the railway track at high speeds and investigated the numeric parameters of the processes by means of mathematical modeling. As a practical purposes is expected to provide the levels of train speed, the boundaries of which can reasonably exclude the possibility of occurrence of the considered effects. Methodology. To achieve these objectives was used principal new model of railway track based on wave propagation theory stresses in the elastic system to study the impact of the movable load, take into account that the deflection in a particular section of the road starts even while the wheels at some distance, and moving the wheels farther from the selected section of the wave front elastic strain continues to spread. According to the results of simulations explores the changing shape of the wave front voltages in time for the foundation under the rail. If the train speeds substantially less than the velocity propagation of elastic waves, the wheel remains in the area implemented deformations. Findings. Alternative calculations for various parameters of the railway track (especially for different soil conditions) determined the levels of train speed, the boundaries of which can reasonably exclude the possibility of occurrence of the considered effects. Originality. The proposed theoretical study and implementation in the form of mathematical models for processes that occur in the perception of load elements of the railway track at high speeds. Practical value. According to simulation results obtained levels of speeds, which define the appearance of the considered dynamic effects in the base under the rail, can be used to justify path construction or establishment of appropriate values of allowable velocities for the implementation of traffic at high speeds.

Social anxiety under load: the effects of perceptual load in processing emotional faces.

Previous studies in the social anxiety arena have shown an impaired attentional control system, similar to that found in trait anxiety. However, the effect of task demands on social anxiety in socially threatening stimuli, such as angry faces, remains unseen. In the present study, 54 university students scoring high and low in the Social Interaction and Performance Anxiety and Avoidance Scale (SIPAAS) questionnaire, participated in a target letter discrimination task while task-irrelevant face stimuli (angry, disgust, happy, and neutral) were simultaneously presented. The results showed that high (compared to low) socially anxious individuals were more prone to distraction by task-irrelevant stimuli, particularly under high perceptual load conditions. More importantly, for such individuals, the accuracy proportions for angry faces significantly differed between the low and high perceptual load conditions, which is discussed in light of current evolutionary models of social anxiety.

Children's Subjective Ratings and Opinions of Typical and Dysphonic Voice After Performing a Language Comprehension Task in Background Noise

Previous studies suggest that dysphonic voices are perceived more negatively than typical voices, and it is possible that vocal perception influences academic achievement and comprehension. This study assessed children's subjective ratings and opinions of a typical and dysphonic voice after performing a language comprehension task in background noise. It also explored if subjective ratings were related to performance in the comprehension task. Ninety-three 8-year-old children participated and were randomly allocated to two groups. A digital version of the Test for Reception of Grammar, version 2 (TROG-2) was used. In TROG-2, the child listens to a sentence and then, out of four possible pictures, selects the picture that corresponds to the sentence content. Each sentence assesses a specific grammatical construction. Test instructions were recorded using one speaker with two different voice qualities (typical voice and provoked dysphonic voice). One group of children performed TROG-2 with the typical voice and the other with the dysphonic voice, both presented in a multitalker babble noise using earphones. All children rated their subjective perception of the voice. The dysphonic voice received poorer ratings than the typical voice. Children making more positive ratings of the voice performed better on earlier blocks in TROG-2, but only in the typical voice group. Children perceived the dysphonic voice more negatively even when listening to the same speaker. Performance is related to the perception of the voice, but only when the perceptual load of the task-relevant stimuli is sufficiently low.

Modelling of situation awareness with perception, attention, and prior and retrospective awareness

Abstract Human awareness under different circumstances is complex and non-trivial to understand. Nevertheless, due to the importance of awareness for safety and efficiency in many domains (e.g., the aviation domain), it is necessary to study the processes behind situation awareness, to eliminate possible errors in action selection that may lead to disasters. Interesting models for situation awareness have been presented, mainly from an ecological psychology perspective, but they are debatable with respect to the latest neurocognitive evidences. With the developments in brain imaging and recording techniques, more and more detailed information on complex cognitive processes becomes available. This provides room to further investigate the mechanisms behind many cognitive phenomena, including situation awareness. This paper presents a computational cognitive agent model for situation awareness from the perspective of action selection, which is inspired by neurocognitive evidences. The model integrates bottom-up and top-down cognitive processes, related to various cognitive states: perception, desires, attention, intention, (prior and retrospective) awareness, ownership, feeling, and communication. Based on the model, various cognitive effects can be explained, such as perceptual load, predictive processes, inferential processes, cognitive controlling, unconscious bias, and conscious bias. A model like this will be useful in domains that benefit from complex simulations of socio-technical systems (e.g. the aviation domain) based on computational models of human behaviour. In such domains, existing agent-based simulations are limited, since most of the agent models do not include realistic nature-inspired processes. The validity of the model is illustrated based on simulations for the aviation domain, focusing on a particular situation where an agent has biased perception, poor comprehension, habitual driven projection, and conflict between prior and retrospective effects on action execution.