Concurrent Visual Task Research Articles

The surprising robustness of visual search against concurrent auditory distraction.

People often complain about distraction by irrelevant sounds that reportedly hamper performance on concurrent visual tasks demanding the allocation of focused attention toward relevant stimuli, such as processing street signs during driving. To study this everyday issue experimentally, we devised a cross-modal distraction paradigm, inspired by a standard visual-distraction paradigm (additional-singleton paradigm) that is highly sensitive to measure interference on the allocation of attention. In a visual-search pop-out task, participants reported whether a salient target (a tilted bar) was present or absent, while a completely irrelevant, but salient auditory distractor accompanied some trials. To our surprise, the results revealed no notable distraction on visual-search performance (controlled for speed-accuracy tradeoffs). Reliable auditory distraction failed to occur even when the distractor was a (highly salient) auditory oddball or was additionally presented with a temporal advantage of 300 ms. However, when the auditory modality was made relevant globally while maintaining its irrelevance to the visual-search task, we finally observed the expected interference effect. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Attention modulates neural measures associated with beat perception.

A growing body of evidence suggests that steady-state evoked potentials may be a useful measure of beat perception, particularly when obtaining traditional, explicit measures of beat perception is difficult, such as with infants or non-human animals. Although attending to a stimulus is not necessary for most traditional applications of steady-state evoked potentials, it is unknown how attention affects steady-state evoked potentials that arise in response to beat perception. Additionally, most applications of steady-state evoked potentials to measure beat perception have used repeating rhythms or real music. Therefore, it is unclear how the steady-state response relates to the robust beat perception that occurs with non-repeating rhythms. Here, we used electroencephalography to record participants' brain activity as they listened to non-repeating musical rhythms while either attending to the rhythms or while distracted by a concurrent visual task. Non-repeating auditory rhythms elicited steady-state evoked potentials at perceived beat frequencies (perception was validated in a separate sensorimotor synchronization task) that were larger when participants attended to the rhythms compared with when they were distracted by the visual task. Therefore, although steady-state evoked potentials appear to index beat perception to non-repeating musical rhythms, this technique may be limited to when participants are known to be attending to the stimulus.

Specific sensorimotor interneuron circuits are sensitive to cerebellar-attention interactions.

Background: Short latency afferent inhibition (SAI) provides a method to investigate mechanisms of sensorimotor integration. Cholinergic involvement in the SAI phenomena suggests that SAI may provide a marker of cognitive influence over implicit sensorimotor processes. Consistent with this hypothesis, we previously demonstrated that visual attention load suppresses SAI circuits preferentially recruited by anterior-to-posterior (AP)-, but not posterior-to-anterior (PA)-current induced by transcranial magnetic stimulation. However, cerebellar modulation can also modulate these same AP-sensitive SAI circuits. Yet, the consequences of concurrent cognitive and implicit cerebellar influences over these AP circuits are unknown.Objective: We used cerebellar intermittent theta-burst stimulation (iTBS) to determine whether the cerebellar modulation of sensory to motor projections interacts with the attentional modulation of sensory to motor circuits probed by SAI.Methods: We assessed AP-SAI and PA-SAI during a concurrent visual detection task of varying attention load before and after cerebellar iTBS.Results: Before cerebellar iTBS, a higher visual attention load suppressed AP-SAI, but not PA-SAI, compared to a lower visual attention load. Post-cerebellar iTBS, the pattern of AP-SAI in response to visual attention load, was reversed; a higher visual attention load enhanced AP-SAI compared to a lower visual attention load. Cerebellar iTBS did not affect PA-SAI regardless of visual attention load.Conclusion: These findings suggest that attention and cerebellar networks converge on overlapping AP-sensitive circuitry to influence motor output by controlling the strength of the afferent projections to the motor cortex. This interaction has important implications for understanding the mechanisms of motor performance and learning.

Measurement of the exploration–exploitation response of dogs through a concurrent visual discrimination task

In many species, the allocation of exploration and exploitation responses to environmental stimuli is important for survival. In this exploratory study, we determined whether dogs (Canis familiaris) explored novel stimuli in a visual discrimination task using food reinforcers. Initially, the dogs were trained with two pairs of simultaneous visual discrimination tasks. Having achieved the learning criterion, the dogs were presented with a pair of stimuli including a novel stimulus and a previously reinforced stimulus in the probe trials (familiar stimulus). Dogs were reinforced by 50% for novel stimuli and 100% for familiar stimuli. The proportions of responses to novel and familiar stimuli in the probe trials were considered to reflect the propensity for exploration and exploitation, respectively. The five dogs tested selected the novel stimulus more frequently (in 22 of the 30 probe trials; binomial test, P = 0.016). Therefore, dogs prefer novel stimuli over familiar ones, suggesting that this species, which is less neophobic than wolves (Canis lupus), would likely allocate more responses to exploration. Comparisons among breeds or with wolves are warranted in future studies.

The Grouping-Induced Numerosity Illusion Is Attention-Dependent.

Perceptual grouping and visual attention are two mechanisms that help to segregate visual input into meaningful objects. Here we report how perceptual grouping, which affects perceived numerosity, is reduced when visual attention is engaged in a concurrent visual task. We asked participants to judge the numerosity of clouds of dot-pairs connected by thin lines, known to cause underestimation of numerosity, while simultaneously performing a color conjunction task. Diverting attention to the concomitant visual distractor significantly reduced the grouping-induced numerosity biases. Moreover, while the magnitude of the illusion under free viewing covaried strongly with AQ-defined autistic traits, under conditions of divided attention the relationship was much reduced. These results suggest that divided attention modulates the perceptual grouping of elements by connectedness and that it is independent of the perceptual style of participants.

Visual load effects on the auditory steady-state responses to 20-, 40-, and 80-Hz amplitude-modulated tones

Ignoring background sounds while focusing on a visual task is a necessary ability in everyday life. If attentional resources are shared between modalities, processing of task-irrelevant auditory information should become attenuated when attentional capacity is expended by visual demands. According to the early-filter model, top-down attenuation of auditory responses is possible at various stages of the auditory pathway through multiple recurrent loops. Furthermore, the adaptive filtering model of selective attention suggests that filtering occurs early when concurrent visual tasks are demanding (e.g., high load) and late when tasks are easy (e.g., low load). To test these models, this study examined the effects of three levels of visual load on auditory steady-state responses (ASSRs) at three modulation frequencies. Subjects performed a visual task with no, low, and high visual load while ignoring task-irrelevant sounds. The auditory stimuli were 500-Hz tones amplitude-modulated at 20, 40, or 80 Hz to target different processing stages of the auditory pathway. Results from bayesian analyses suggest that ASSRs are unaffected by visual load. These findings imply that attentional resources are modality specific and that the attentional filter of auditory processing does not vary with visual task demands.

The Nature of Haptic Working Memory Capacity and Its Relation to Visual Working Memory

Abstract I conducted three experiments to investigate haptic working memory capacity using a haptic change detection task with 2D stimuli. I adopted a single-task paradigm comprising haptic single-feature (orientation or texture) and haptic multifeature (orientation and texture) conditions in Experiment 1 and a dual-task paradigm with a primary haptic orientation or texture change detection task and a concurrent secondary visual shape or colour change detection task in Experiments 2–3. I observed that in the single-task paradigm, haptic change detection capacity was higher for single features than it was for multiple features. In haptic working memory, unlike in visual working memory, features of two different dimensions within an object cannot be integrated. In the dual-task paradigm, interference was observed when the concurrent visual shape change detection task was combined with the haptic orientation change detection task although interference was not observed when the concurrent visual colour change detection task was combined with it. In addition, the concurrent visual shape or colour change detection task did not interfere with the capacity for haptic texture memory, which was higher than that for haptic orientation memory. These findings demonstrate that geometric properties perhaps retained a common storage system shared between haptic working memory and visual working memory; however, haptic texture might be retained in an independent stable storage system that is haptic-specific.

Making It Harder to “See” Meaning: The More You See Something, the More Its Conceptual Representation Is Susceptible to Visual Interference

Does the perceptual system for looking at the world overlap with the conceptual system for thinking about it? We conducted two experiments (N = 403) to investigate this question. Experiment 1 showed that when people make simple semantic judgments on words, interference from a concurrent visual task scales in proportion to how much visual experience they have with the things the words refer to. Experiment 2 showed that when people make the same judgments on the very same words, interference from a concurrent manual task scales in proportion to how much manual (but critically, not visual) experience people have with those same things. These results suggest that the meanings of frequently visually experienced things are represented (in part) in the visual system used for actually seeing them, that this visually represented information is a functional part of conceptual knowledge, and that the extent of these visual representations is influenced by visual experience.

Learning to suppress a distractor is not affected by working memory load

Where and what we attend to is not only determined by our current goals but also by what we have encountered in the past. Recent studies have shown that people learn to extract statistical regularities in the environment resulting in attentional suppression of high-probability distractor locations, effectively reducing capture by a distractor. Here, we asked whether this statistical learning is dependent on working memory resources. The additional singleton task in which one location was more likely to contain a distractor was combined with a concurrent visual working memory task (Experiment 1) and a spatial working memory task (Experiment 2). The result showed that learning to suppress this high-probability location was not at all affected by working memory load. We conclude that learning to suppress a location is an implicit and automatic process that does not rely on visual or spatial working memory capacity, nor on executive control resources. We speculate that extracting regularities from the environment likely relies on long-term memory processes.

Vision Does Not Necessarily Stabilize the Head in Space During Continuous Postural Perturbations.

Vision favors head stabilization in space during perturbations of standing balance. This is particularly obvious under conditions of continuous predictable perturbations as during sinusoidal antero-posterior (A-P) translations of the supporting platform. We tested here the hypothesis that under this condition the head can instead undergo large A-P oscillations, when a precision visual task is concurrently performed. We compared the head oscillations across four conditions while standing on a continuously translating platform. Eyes open (EO, no visual task), EO while reading a text fixed to the moving platform (EO-TP), EO while reading a text fixed to earth-ground (EO-TG), eyes-closed (EC). The platform translated at 0.2 and 0.6 Hz. Participants were young adult subjects, who received no particular instruction except reading the text aloud when required. Markers fixed on head, platform and text-sheet were captured by an optoelectronic device. We found that head oscillations were larger with EC than under all EO conditions. The oscillations were the least with EO and EO-TG, and intermediate with EO-TP. This was true under both low and high translation frequency, in spite of broadly smaller head oscillations at high frequency, common to all visual conditions. The distance between the head and the text was quite constant with EO-TP but fluctuated with EO-TG. The basic whole-body coordination features were moderately similar under all conditions, as assessed by the head-platform correlation coefficients and time lags. It appears that vision does not produce head stabilization in space when a concurrent visual task requiring focusing on a reading-text moving with the platform is performed. Contrary to traditional views centered on the stabilizing effect of vision under both static and dynamic conditions, the results show that head stabilization, normally ensuring a reference for inertial guidance for body balance, can be revoked by the CNS to allow performance of a non-postural task. This novel paradigm can shift long-standing views on the effect of vision on equilibrium control and be considered a potential exercise treatment for enhancing the multisensory integration process in people with balance problems.

Opposing effects of stimulus-driven and memory-driven attention in visual search.

When one searches for a specific target in a cluttered visual scene, a perceptually salient stimulus or a stimulus that matches working memory's contents is prioritized for attentional selection. In the present study, we aimed at clarifying under which circumstance stimulus-driven attention or memory-driven attention is more pronounced. We hypothesized that one crucial factor affecting stimulus-driven versus memory-driven attention is how a concurrent visual search task is performed. To address this issue, we employed two visual search tasks whose underlying mechanisms are known to be different: Landolt-C search and orientation feature search. One group of participants performed visual search tasks containing a memory-matching stimulus, and the other group conducted searches in the presence of a salient singleton distractor. The results showed that the effects of stimulus-driven and memory-driven attention differed, depending on the cognitive mechanisms underlying the visual search tasks. A memory-matching stimulus captured attention when participants performed the Landolt-C search, whereas this capture was diminished under feature search. In contrast, capture by the salient singleton distractor was found only under feature search. These results demonstrate that the nature of the underlying visual search tasks is an important factor for observing stimulus-driven versus memory-driven attention. Our results also provide a potential solution to resolve current debate regarding memory-driven attention in visual search.

Ipsilesional Impairments of Visual Awareness After Right-Hemispheric Stroke.

Unilateral brain damage following stroke frequently hampers the processing of contralesional space. Whether and how it also affects the processing of stimuli appearing on the same side of the lesion is still poorly understood. Three main alternative hypotheses have been proposed, namely that ipsilesional processing is functionally (i) hyperefficient, (ii) impaired, or (iii) spared. Here, we investigated ipsilesional space awareness through a computerized paradigm that exploits a manipulation of concurrent information processing demands (i.e., multitasking). Twelve chronic right-hemisphere stroke patients with a total lack of awareness for the contralesional side of space were administered a task that required the spatial monitoring of two locations within the ipsilesional hemispace. Targets were presented immediately to the right of a central fixation point (3° eccentricity), or farther to the right toward the screen edge (17° eccentricity), or on both locations. Response to target position occurred either in isolation or while performing a concurrent visual or auditory task. Results showed that most errors occurred when two targets were simultaneously presented and patients were faced with additional task demands (in the visual or auditory modalities). In the context of concurrent visual load, ipsilesional targets presented at the rightmost location were omitted more frequently than those presented closer to fixation. This pattern qualifies ipsilesional processing in right-hemisphere stroke patients as functionally impaired, arguing against the notion of ipsilesional hyperperformance, especially when under visual load.

Steady-state visual evoked potentials reveal enhanced neural responses to illusory surfaces during a concurrent visual attention task

Under natural viewing conditions, visual stimuli are often obscured by occluding surfaces. To aid object recognition, the visual system actively reconstructs the missing information, as exemplified in the classic Kanizsa illusion, a phenomenon termed “modal completion”. Single-cell recordings in monkeys have shown that neurons in early visual cortex respond to illusory contours, but it has proven difficult to measure the neural correlates of modal completion in humans. We used electroencephalography (EEG) to measure steady-state visual-evoked potentials (SSVEPs) from disks with quarter segments removed to induce an illusory shape (or rotated to eliminate the illusory square in control trials). Opposing pairs of inducers were tagged with one of two flicker frequencies (2.5 or 4 Hz). During stimulus presentations, participants performed an attention task at fixation that required them to judge the orientation of a briefly flashed central bar while ignoring congruent (same orientation) or incongruent (different orientation) flanker bars that appeared on or off the illusory surface. Importantly, the occurrence of any illusory shape was never task relevant. Frequency-based analyses revealed that SSVEP amplitudes were reliably enhanced for trials in which an illusory square appeared, relative to control trials, at 4, 5 and 8 Hz and at an intermodulation frequency of 13 Hz. Participants' reaction times in the flanker task were significantly slower for incongruent versus congruent trials, and this distractor interference effect occurred only in the presence of an illusory surface and not in the control condition. Our results reveal a robust neural correlate of modal completion in the human visual system and provide evidence that visual completion can affect attentional control processes as deployed in a flanker task.

Quantifying Intermodal Distraction by Emotion During Math Performance: An Electrophysiological Approach.

Emotionally engaging stimuli are powerful competitors for limited attention capacity. In the cognitive neuroscience laboratory, the presence of task-irrelevant emotionally arousing visual distractors prompts decreased performance and attenuated brain responses measured in concurrent visual tasks. The extent to which distraction effects occur across different sensory modalities is not yet established, however. Here, we examined the extent and time course of competition between a naturalistic distractor sound and a visual task stimulus, using dense-array electroencephalography (EEG) recordings from 20 college students. Steady-state visual evoked potentials (ssVEPs) were quantified from EEG, elicited by periodically flickering vignettes displaying basic arithmetic problems – the participants’ primary task. Concurrently, low-arousing and high-arousing sounds were presented, as well as auditory pink noise, used as a control. Capitalizing on the temporal dynamics of the ssVEP signal allowed us to study intermodal interference of the sounds with the processing of the visual math problems. We observed that high-arousing sounds were associated with diminished visuocortical responses and poor performance, compared to low-arousing sounds and pink noise, suggesting that emotional distraction acts across modalities. We discuss the role of sensory cortices in emotional distraction along with implications for translational research in educational neuroscience.

Glaucoma-Related Differences in Gaze Behavior When Negotiating Obstacles.

PurposeSafe navigation requires avoiding objects. Visual field loss may affect how one visually samples the environment, and may thus contribute to bumping into objects and falls. We tested the hypothesis that gaze strategies and the number of collisions differ between people with glaucoma and normally sighted controls when navigating around obstacles, particularly under multitasking situations.MethodsTwenty persons with moderate–severe glaucoma and 20 normally sighted controls walked around a series of irregularly spaced vertical obstacles under the following three conditions: walking with obstacles only, walking and counting backward to simulate a conversation, and walking while performing a concurrent visual search task to simulate locating a landmark. We quantified gaze patterns and the number of obstacle contacts.ResultsCompared with controls, people with glaucoma directed gaze closer to their current position (P < 0.05). They also directed a larger proportion of fixations (in terms of number and duration) to obstacles (P < 0.05). Despite this finding, considerably more people with glaucoma contacted an obstacle (P < 0.05). Multitasking led to changes in gaze behavior in both groups, and this was accompanied by a large increase in obstacle contacts among those with glaucoma (P < 0.05).ConclusionsGlaucoma alters gaze patterns when negotiating a series of obstacles and increases the likelihood of collisions. Multitasking in this situation exacerbates these changes.Translational RelevanceUnderstanding glaucoma-related changes in gaze behavior during walking in cluttered environments may provide critical insight for orientation and mobility specialists and guide the design of gaze training interventions to improve mobility.

Anterior paracingulate and cingulate cortex mediates the effects of cognitive load on speech sound discrimination

Perceiving speech while performing another task is a common challenge in everyday life. How the brain controls resource allocation during speech perception remains poorly understood. Using functional magnetic resonance imaging (fMRI), we investigated the effect of cognitive load on speech perception by examining brain responses of participants performing a phoneme discrimination task and a visual working memory task simultaneously. The visual task involved holding either a single meaningless image in working memory (low cognitive load) or four different images (high cognitive load). Performing the speech task under high load, compared to low load, resulted in decreased activity in pSTG/pMTG and increased activity in visual occipital cortex and two regions known to contribute to visual attention regulation—the superior parietal lobule (SPL) and the paracingulate and anterior cingulate gyrus (PaCG, ACG). Critically, activity in PaCG/ACG was correlated with performance in the visual task and with activity in pSTG/pMTG: Increased activity in PaCG/ACG was observed for individuals with poorer visual performance and with decreased activity in pSTG/pMTG. Moreover, activity in a pSTG/pMTG seed region showed psychophysiological interactions with areas of the PaCG/ACG, with stronger interaction in the high-load than the low-load condition. These findings show that the acoustic analysis of speech is affected by the demands of a concurrent visual task and that the PaCG/ACG plays a role in allocating cognitive resources to concurrent auditory and visual information.

Can pupillometry index auditory attentional capture in contexts of active visual processing?

ABSTRACTThe rare presentation of a sound that deviates from the auditory background tends to capture attention, which is known to impede cognitive functioning. Such disruption is usually measured using performance on a concurrent visual task. Growing evidence recently showed that the pupillary dilation response (PDR) could index the attentional response triggered by a deviant sound. Given that the pupil diameter is sensitive to several vision-related factors, it is unclear whether the PDR could serve to study attentional capture in such contexts. Hence, the present study aimed at verifying whether the PDR can be used as a proxy for auditory attentional capture while a visual serial recall task (Experiment 1) or a reading comprehension task (Experiment 2) – respectively producing changes in luminance and gaze position – is being performed. Results showed that presenting a deviant sound within steady-state standard sounds elicited larger PDRs than a standard sound. Moreover, the magnitude of these PDRs was positively related to the amount of performance disruption produced by deviant sounds in Experiment 1. Performance remained unaffected by the deviants in Experiment 2, thereby implying that the PDR may be a more sensitive attention-capture index than behavioural measures. These results suggest that the PDR can be used to assess attentional capture by a deviant sound in contexts where the pupil diameter can be modulated by the visual environment.

Coordination of Gaze Behavior and Foot Placement During Walking in Persons With Glaucoma.

Vision normally provides environmental information necessary to direct the foot to safe locations during walking. Peripheral visual field loss limits what a person can see, and may alter how a person visually samples the environment. Here we tested the hypothesis that the spatial-temporal coupling between gaze and stepping in a precision-based walking task is altered in persons with glaucoma, particularly under dual task situations, and results in reduced foot-placement accuracy. Twenty persons with glaucoma and 20 normally sighted controls performed a precision walking task that involved stepping to the center of 4 targets under 3 conditions: targets only, walking, and counting backwards to simulate a conversation, and walking while performing a concurrent visual search task to simulate locating a landmark. We quantified foot-placement error and error variability with respect to the targets, as well as saccade and fixation timing with respect to foot placement. Compared with controls, persons with glaucoma looked earlier at future stepping targets (with respect to toe-off of the foot) in the targets only and count conditions, and transferred gaze away sooner from the current stepping target in all conditions (P<0.05). Persons with glaucoma also had increased foot-placement error, particularly in the count condition, and increased foot-placement error variability compared with normally sighted controls (P<0.05). Glaucoma significantly disrupts gaze-foot coordination and results in less accurate foot placement when precision is required during walking. This may increase the risk of trips and falls in this population.

Attentional state modulates the effect of an irrelevant stimulus dimension on perception.

Covariations of acoustic features provide redundancy in rapidly changing soundscapes: Hearing one feature enables a listener to infer another if these 2 features normally covary. However, it is unknown whether situational demands affect the degree to which covariations influence perceptual inferences. We exploited a perceptual interdependency between modulation rate and frequency and examined, in 6 experiments, whether challenging situations would alter the degree to which people rely on frequency information to make decisions about modulation rate. Participants listened to amplitude-modulated (AM) sounds with modulation rates (∼5 Hz) either decreasing or increasing over time and identified the direction of the rate change. Participants were instructed to ignore carrier frequency, which either decreased or increased (∼1,300 Hz) over time. We observed that participants were more likely to perceive the modulation rate as slowing down when frequency decreased and as speeding up when frequency increased (AM-rate change illusion). The magnitude of the illusion increased when uninformative cues (compared with informative cues) prohibited regulation of attention to sounds, and under distraction introduced by a concurrent visual motion-tracking task. The evidence suggests that the attentional state affects how strongly people rely on featural covariations to make perceptual inferences. (PsycINFO Database Record

Neural Representation of Working Memory Content Is Modulated by Visual Attentional Demand.

Recent theories assert that visual working memory (WM) relies on the same attentional resources and sensory substrates as visual attention to external stimuli. Behavioral studies have observed competitive tradeoffs between internal (i.e., WM) and external (i.e., visual) attentional demands, and neuroimaging studies have revealed representations of WM content as distributed patterns of activity within the same cortical regions engaged by perception of that content. Although a key function of WM is to protect memoranda from competing input, it remains unknown how neural representations of WM content are impacted by incoming sensory stimuli and concurrent attentional demands. Here, we investigated how neural evidence for WM information is affected when attention is occupied by visual search-at varying levels of difficulty-during the delay interval of a WM match-to-sample task. Behavioral and fMRI analyses suggested that WM maintenance was impacted by the difficulty of a concurrent visual task. Critically, multivariate classification analyses of category-specific ventral visual areas revealed a reduction in decodable WM-related information when attention was diverted to a visual search task, especially when the search was more difficult. This study suggests that the amount of available attention during WM maintenance influences the detection of sensory WM representations.