Absence Of Distractors Research Articles

Alpha desynchronization during the filtering initiation phase reflects active processing of distractors

The ability to select task-relevant information and filter out task-irrelevant information is critical to our success in daily goal-directed behavior. Researchers call this ability filtering efficiency and divide it into three cognitive processing stages: detection of distractors, initiation of filtering, and unnecessary storage. Although researchers have conducted more studies on ERP components related to filtration efficiency, there are few studies related to neural oscillations. Alpha oscillation activity is related to the active processing of information and the suppression of distractors. In the current EEG study, we used the change detection task with distracted items to examine whether alpha activity during filtering initiation reflects reactive suppression of distractors by manipulating memory load levels and the presence or absence of distractors. Results showed that, the presence of the distractors caused an increase in the degree of desynchronization of the alpha oscillations, and in the subsequent time, the alpha activity level returned to a level consistent with the absence of interference conditions. Phase synchronization between frontal and posterior brain regions in the upper alpha oscillations found no effects associated with distractors. Based on these results, we believed that the alpha activity during the filtering initiation phase reflected the active processing of distractors, but this may also be due to lower perceptual load of the target items. In addition, we observed a dominance effect of the right hemisphere in both time-frequency results and connectivity results. We speculate that this effect is related to the activation of the right ventral frontoparietal network.

Aversive reinforcement improves visual discrimination learning in free-flying wasps (Vespula vulgaris)

Understanding and assessing the capacity for learning, memory, and cognition in non-model organisms is a growing field. In invertebrate cognition, eusocial hymenopteran species such as honeybees, bumblebees, and ants are well-studied for their learning and memory abilities due to decades of research providing well-tested methods of training and assessing cognition. In the current study, we assess the use of different conditioning methods on visual learning in a non-model hymenopteran species which is becoming increasingly used in learning and memory tasks, the European wasp (Vespula vulgaris). We trained individual wasps to learn to discriminate between perceptually similar colours using absolute conditioning (reward on target stimulus in the absence of distractors), appetitive differential conditioning (reward on target stimulus and no outcome for incorrect stimulus), or appetitive-aversive differential conditioning (reward on target stimulus and aversive outcome for incorrect stimulus). When trained with absolute conditioning, wasps were unable to learn to discriminate between perceptually similar colours. However, when trained with appetitive differential conditioning or appetitive-aversive differential conditioning, wasps were able to learn to discriminate between two similar colours, although they performed best when an aversive reinforcement was provided during training. Our results show similarities to learning behaviour in honeybees and bumblebees, and provide insight into the learning and cognition of a non-model invertebrate. Our findings provide important comparative data to aid in understanding the evolution of learning and memory in hymenopterans.Significance statementForaging insects such as bees, ants, and wasps visit a variety of food sources such as flowers, insect prey, and rotting fruit. Many of these insects must learn and recall resource traits such as location, scent, shape, colour, and size. To understand the process of learning in insects which are comparatively less studied than those such as honeybees and bumblebees, we trained wasps to discriminate between two similar colours using three different types of conditioning methods. Wasps were best able to learn to discriminate between the similar colours when trained with appetitive-aversive differential conditioning, where a reward is provided for a correct choice and an aversive outcome was providing for an incorrect choice. Our results show that similar to popular invertebrate cognition models, wasp learning is improved when an aversive outcome is introduced for incorrect choices.

Predictors of Human Efficiency in Radar Detection Tasks

Aegis operators simultaneously locate and monitor the activity of several hostile targets, intervening and alerting their team when appropriate. Utilizing the Aegis Combat System, operators find, track, and respond to dynamic targets on a radar screen. The demand that operators undergo is often high, inevitably causing strain on cognitive functions and detriments to performance. We applied model-based measures, Cost and Multitasking Throughput, to quantify the influence of external factors on processing efficiency in radar task(s). We captured the influence of three experimental manipulations, each of three levels, on human efficiency to track the location of hostiles and/or detect brief radar interference. We collected participants’ performance to complete a multiple object tracking (MOT) task and an electronic attack detection task (EA) using a radar display. A factorial manipulation of conditions comprised changes to task(s) (EA, MOT, or both), the number of targets to track (2, 4, or 6) and the presence or absence of distractors, deemed 'friendlies' (between 500-1000 total tracks). Our novel individual- and model-based approach provided quantitative estimates of human efficiency. We compared the observed variation in efficiency among predictors including target quantity, visual load, and the presence of one or two interrelated tasks. Through quantifying the relationship of these variables to radar detection tasks, we discuss implications of our findings and provide a framework to examine how system designers may develop tools to alleviate observed cognitive demands and/or counter potential threats of electronic attacks in radar detection and tracking tasks.

Phonological Working Memory Representations in the Left Inferior Parietal Lobe in the Face of Distraction and Neural Stimulation.

The neural basis of phonological working memory (WM) was investigated through an examination of the effects of irrelevant speech distractors and disruptive neural stimulation from transcranial magnetic stimulation (TMS). Embedded processes models argue that the same regions involved in speech perception are used to support phonological WM whereas buffer models assume that a region separate from speech perception regions is used to support WM. Thus, according to the embedded processes approach but not the buffer approach, irrelevant speech and TMS to the speech perception region should disrupt the decoding of phonological WM representations. According to the buffer account, decoding of WM items should be possible in the buffer region despite distraction and should be disrupted with TMS to this region. Experiment 1 used fMRI and representational similarity analyses (RSA) with a delayed recognition memory paradigm using nonword stimuli. Results showed that decoding of memory items in the speech perception regions (superior temporal gyrus, STG) was possible in the absence of distractors. However, the decoding evidence in the left STG was susceptible to interference from distractors presented during the delay period whereas decoding in the proposed buffer region (supramarginal gyrus, SMG) persisted. Experiment 2 examined the causal roles of the speech processing region and the buffer region in phonological WM performance using TMS. TMS to the SMG during the early delay period caused a disruption in recognition performance for the memory nonwords, whereas stimulations at the STG and an occipital control region did not affect WM performance. Taken together, results from the two experiments are consistent with predictions of a buffer model of phonological WM, pointing to a critical role of the left SMG in maintaining phonological representations.

Assessment of Attentional Processes in Patients with Anxiety-Depressive Disorders Using Virtual Reality

To characterize the attention deficits in one-hundred-fifteen participants, comprising two types of clinical profiles (affective and anxiety disorder), through a test of continuous VR execution. Method: Three tests (i.e., Nesplora Aquarium, BDI, and STAI) were used to obtain a standardized measure of attention, as well as the existence and severity of depression and anxiety, respectively. Results: Significant differences (CI = 95%) were found between the control group and the group with depression, in variables related to the speed of visual processing (p = 0.008) in the absence of distractors (p = 0.041) and during the first dual execution task (p = 0.011). For scores related to sustained attention, patients with depression and those with anxiety did not differ from controls. Our results suggest attentional deficits in both clinical populations when performing a continuous performance test that involved the participation of the central executive system of working memory.

Age-related changes in visual search: manipulation of colour cues based on cone contrast and opponent modulation space

Reduced retinal illuminance affects colour perception in older adults, and studies show that they exhibit deficiencies in yellow-blue (YB) discrimination. However, the influence of colour cues on the visual attention in older individuals remains unclarified. Visual attention refers to the cognitive model by which we prioritise regions within the visual space and selectively process information. The present study aimed to explore the effect of colour on visual search performance in older observers. In our experiment, younger observers wearing glasses with a filter that simulated the spectral transmittance of the aging human lens and older observers performed two types of search tasks, feature search (FS) and conjunction search (CS), under three colour conditions: red-green, YB, and luminance. Targets and distractors were designed on the basis of the Derrington–Krauskopf–Lennie colour representation. In FS tasks, reaction times changed according to colour in all groups, especially under the YB condition, regardless of the presence or absence of distractors. In CS tasks with distractors, older participants and younger participants wearing glasses showed slower responses under chromatic conditions than under the achromatic condition. These results provide preliminary evidence that, for older observers, visual search performance may be affected by impairments in chromatic colour discrimination.

Objective Assessment in Continual Medical Education (CME) Medical Objective Assessment in System Control

Existing examinations in postgraduate education and continuing medical education (CME) are not perfect. Modern assessment does not reflect disadvantages of older responders, for whom more time for reply is needed. Specialists with wide clinical experience may choose more than one correct answer in alternative questions. Reduced ability to remember in older people restricts examination without additional sources of information.We offer an individualised system for testing doctors. It provides personalised choice of examination questions using multiple choice questions with weight characteristics and absence of distractors, interactive cooperation in case of negative answers and the final decision of an expert in relation to the person tested. A special algorithm is proposed for typical questions that combines the advantages of known approaches to testing. The questioning system is complex for the creators of tests, but is more convenient and objective than existing ones for medical doctors.

Differential impact of exogenous and endogenous attention on the contrast sensitivity function across eccentricity.

Both exogenous and endogenous covert spatial attention enhance contrast sensitivity, a fundamental measure of visual function that depends substantially on the spatial frequency and eccentricity of a stimulus. Whether and how each type of attention systematically improves contrast sensitivity across spatial frequency and eccentricity are fundamental to our understanding of visual perception. Previous studies have assessed the effects of spatial attention at individual spatial frequencies and, separately, at different eccentricities, but this is the first study to do so parametrically with the same task and observers. Using an orientation discrimination task, we investigated the effect of attention on contrast sensitivity over a wide range of spatial frequencies and eccentricities. Targets were presented alone or among distractors to assess signal enhancement and distractor suppression mechanisms of spatial attention. At each eccentricity, we found that exogenous attention preferentially enhanced spatial frequencies higher than the peak frequency in the baseline condition. In contrast, endogenous attention similarly enhanced a broad range of lower and higher spatial frequencies. The presence or absence of distractors did not alter the pattern of enhancement by each type of attention. Our findings reveal how the two types of covert spatial attention differentially shape how we perceive basic visual dimensions across the visual field.

How visual working memory handles distraction: cognitive mechanisms and electrophysiological correlates

ABSTRACT The ability to selectively encode relevant information (filtering ability) is crucial to make best use of the severely limited space that visual working memory (VWM) provides. This review considers why filtering ability is important, how it is measured, and it discusses how filtering might be implemented computationally at the cognitive and neuronal level. Based on theoretical considerations, we explore the possibility that filtering ability involves not only the suppression of irrelevant, but also the enhancement of relevant information – functions that might be implemented by different brain mechanisms; and we review behavioural and electrophysiological data in light of the various resulting model versions. We also highlight that filtering is better understood as coordinated brain network activity, rather than being the function of a single region. Broadcasting of control signals from prefrontal cortex appears critical in upholding information in posterior cortical areas in the absence of distractors. The very same ability might also support selective processing of relevant information in the presence of distractors. These ideas provide a novel explanation for the relation between filtering ability and VWM capacity and thereby (re-)establish a central role of filtering ability in general VWM functioning.

Refining the Empirical Constraints on Computational Models of Spatial Working Memory in Schizophrenia

BackgroundImpairments in spatial working memory (sWM) have been well documented in schizophrenia. Here we provide a comprehensive test of a microcircuit model of WM performance in schizophrenia that predicts enhanced effects of increasing delay duration and distractors based on a hypothesized imbalance of excitatory and inhibitory processes. MethodsModel predictions were tested in 41 people with schizophrenia (PSZ) and 32 healthy control subjects (HCS) performing an sWM task. In one condition, a single target location was followed by delays of 0, 2, 4, or 8 seconds. In a second condition, distractors were presented during the 4-second delay interval at 20°, 30°, 40°, 50°, or 90° from the original target location. ResultsPSZ showed less precise sWM representations than HCS, and the rate of memory drift over time was greater in PSZ than in HCS. Relative to HCS, the spatial recall responses of PSZ were more repelled by distractors presented close to the target location and more attracted by distractors presented far from the target location. The degree of attraction to distant distractors was correlated with the rate of memory drift in the absence of distractors. ConclusionsConsistent with the microcircuit model, PSZ exhibited both a greater rate of drift and greater attraction to distant distractors relative to HCS. These two effects were correlated, consistent with the proposal that they arise from a single underlying mechanism. However, the repulsion effects produced by nearby distractors were not predicted by the model and thus require an updated modeling framework.

Taste sensitivity and lifestyle are associated with food preferences and BMI in children

Oral food perception together with lifestyle may affect food preferences and choices, influencing weight gain and obesity development. The present study was designed to evaluate the association of biological (taste sensitivity) and lifestyle variables with children food preferences, assessing whether all these variables contribute to explain BMI percentile. After anthropometric evaluation, 387 children were classified for bitter and sweet taste sensitivities. Socioeconomic/lifestyle aspects and hedonics for 36 foods were collected. Watching TV during meals associate with lower preference for several vegetables, as well as being sweet taste low sensitive, in the case of girls. Moreover, regression analysis showed that bitter taste sensitivity is one of the variables contributing to explain high BMI percentiles. These results present evidences that both biological and socioeconomic and the attention that is given to food (eating in the presence or absence of distractors) are aspects that should be considered in children nutrition to prevent obesity.

Cue frequency modulates cuing effect either in the presence or in the absence of distractors

A novel, salient stimulus, even though it is not related to a concurrent goal-directed behavior, powerfully captures people's attention. While this stimulus-driven attentional capture has long been presumed to take place in a purely bottom-up or automatic manner, growing evidence shows that a number of top-down factors modulate the stimulus-driven capture of attention. Recent studies pointed out the cue presentation frequency is such a factor; the capture of attention by a salient, task-irrelevant cue increased as its presentation frequency decreased. Expanding these studies, we investigated how the modulatory effect of the cue frequency differs depending on the level of competition between multiple stimuli. As results, we found that an infrequently presented cue exerted stronger capture effect than a frequently presented cue, either in the presence or in the absence of distractors. Importantly, in the absence of distractors, performance difference elicited by the frequently present cue was due to non-attentional sensory artifacts or decisional noise. However, the same frequent cue evoked genuine attentional effect when multiple distractors accompanied the target, evoking stimulus-driven competition. Taken together, these results demonstrate that the effect of attentional cue is modulated by cue frequency, and this modulation is also affected by stimulus-driven competition.

Value-driven attentional capture in neglect

ObjectiveRecent studies suggest that motivational cues such as rewards may be a powerful determinant of attentional selection, both in healthy subjects and in brain-damaged patients suffering from neglect. However, the exact brain mechanisms underlying these effects and their relation to other well-known attentional systems are still poorly known. MethodsWe designed a visual search paradigm to examine how value-based attentional priority could modulate spatial orienting in patients with pathological biases due to neglect after right hemispheric stroke. Targets were preceded by exogenous valid or invalid spatial cues, in the presence or absence of distractors that were associated with high reward values subsequent to an initial reinforcement training phase. ResultsWe found that the learned reward value of distractors interfered with spatial reorienting toward the left (neglected) side when neglect patients were invalidly cued to the right side. Moreover, the presence of reward-associated distractors in the contralesional field interfered most with the detection of task-relevant targets on the same side, and this interference was exaggerated with more severe neglect. Voxelwise anatomical lesion analysis indicated that damage to the right angular gyrus, as well as lateral occipital and inferior temporal areas of the right hemisphere, were associated with stronger value-driven attentional effects. ConclusionsVisual stimuli previously associated with rewards receive higher attentional priority during visual search despite pathological spatial biases due to neglect, and thus interfere with orienting to contralesional targets, presumably by competing with top-down mechanisms controlling exogenous spatial attention. Reward signals may bias neural activity evoked by visual stimuli, independent of conscious control, through a common priority map integrating several different attentional influences. These results do not only provide novel insights to link spatial orienting and motivational signals within current models of attention, but also open new perspectives that may usefully be exploited for neurological rehabilitation strategies in patients suffering from attentional deficits and neglect.

Learning through clamor: The allocation and perception of study time in noise.

Memory tasks involve a degree of judgment and strategic decision-making, based upon the perceived benefits of particular learning, maintenance and recall strategies. The consequences of these metacognitive judgments for memory have been amply documented under experimental conditions that require participants to focus upon a task in the absence of distractors. Eight experiments consider the impact of less benign environmental conditions-specifically, the presence of distracting speech-upon the metacognitive aspects of memory. Distraction reliably disrupted free recall and, as indicated by judgments of learning, participants were aware of this effect. However, because participants did not adjust study time in compensation, the distraction effect was exaggerated relative to experimenter-imposed presentation rates. This finding appears to be the consequence of distraction-induced disruption of time perception at encoding, rather than any deliberate strategy. The results highlight the need to consider the impact of more challenging environments on metacognition generally. (PsycINFO Database Record

The experimental parameters that affect attentional modulation of the ERP C1 component

ABSTRACTThere is current debate as to whether spatial attention can modulate V1 activity during the initial wave of visual processing. Research on this topic has focused on the event-related potential (ERP) C1 component, which primarily reflects activity in V1. The purpose of the present selective review was to compare experimental parameters across spatial attention studies to determine whether certain stimulus, task, or analysis conditions were more likely to produce significant C1 attention effects. Specifically, C1 attention effects were evaluated as a function of visual field location, presence or absence of distractors, load (perceptual or attentional), cue type (endogenous or exogenous), and electrode location. As the C1 component has its peak magnitude at midline parietal-occipital electrodes, only studies that measured C1 attention effects at these electrode locations were considered. Furthermore, only studies that manipulated spatial attention, and no other factors, were considered. The current analysis indicated that to maximize sensitivity to C1 attention effects, stimuli should be in the upper visual field, there should be distractors, conditions should be high perceptual or attentional load, there should be exogenous cuing, and effects should be measured at midline parietal-occipital electrodes POz, Pz, and CPz.

Unchanging Capacity

Complex workspaces often require operators to divide attention between information within the visual periphery and a visual central task. For an air traffic controller, for example, monitoring complex displays while also watching for potential hazards is essential for avoiding aircraft collisions. In such environments, fast and accurate detection of peripheral events may be critical for safe performance. Presenting targets redundantly offers a potential way of speeding up target detection (Little, Eidels, Fific, & Wang, 2015; Townsend & Eidels, 2011). It remains unclear, however, whether redundant-target processing remains efficient with a concurrent central task. A series of experiments examined the effects of dual-tasking on peripheral redundant-target processing, either between- (Experiments 1a & 1b) or within-participants (Experiment 4). Furthermore, Experiments 2 and 3 manipulated target-distractor discriminability and distractor presence to examine the effects of target salience on dual-task processing efficiency. One hundred and one undergraduate students ( N =20 in each of Experiments 1a to 3; N = 21 in Experiment 4) performed a redundant-target task either by itself (Experiment 1a) or whilst performing a manual tracking task (Experiments 1b-4). The tracking task required participants to maneuver a joystick using both hands to align a cursor with a moving red target. The detection task required participants to press a joystick button bimanually whenever a target appeared at a location in the peripheral visual field. Experiments 1a, 1b, and Experiment 4 employed “T” as the target item and “L” as distractor items that appeared randomly rotated in 90° steps. In Experiment 2, target salience was increased by employing “X” as the target item and “O” for the distractor items. Experiment 3 tested peripheral target processing in the absence of distractors; hence, only the target item “T” was employed. Processing efficiency in the target-detection task was calculated using measures of resiliency (Little et al., 2015) or workload capacity (Townsend & Eidels, 2011). In all five experiments, processing of redundant targets was less efficient than predicted by a standard parallel race model (Raab, 1962; Townsend & Eidels, 2011). Surprisingly, processing efficiency differed negligibly between the single and dual-task conditions. Capacity may be protected from task-load effects due to separate information-processing resource pools within the central and peripheral visual fields (Wickens, 2002). Neither increasing the discriminability between targets and distractors, nor removing distractors entirely, had any effect on redundant-target processing efficiency. Results suggest target processing in the visual periphery is capacity-limited, but that processing efficiency is robust against changes to concurrent task load or target salience.

Target Selection Signals Influence Perceptual Decisions by Modulating the Onset and Rate of Evidence Accumulation

Computational and neurophysiological research has highlighted neural processes that accumulate sensory evidence for perceptual decisions. These processes have been studied in the context of highly simplified perceptual discrimination paradigms in which the physical evidence appears at times and locations that are either entirely predictable or exogenously cued (e.g., by the onset of the stimulus itself). Yet, we are rarely afforded such certainty in everyday life. For example, when driving along a busy motorway, we must continually monitor the movements of surrounding vehicles for events that call for a lane change. In such scenarios, it is unknown which of the continuously present information sources will become relevant or when. Although it is well established that evidence integration provides an effective mechanism for countering the impact of noise, the question of how this mechanism is implemented in the face of uncertain evidence onsets has yet to be answered. Here, we show that when monitoring two potential sources of information for evidence occurring unpredictably in both time and space, the human brain employs discrete, early target selection signals that significantly modulate the onset and rate of neural evidence accumulation, and thereby the timing and accuracy of perceptual reports. These selection signals share many of the key characteristics of the N2pc component highlighted in the literature on visual search yet are present even in the absence of distractors and under situations of low temporal and spatial uncertainty. These data provide novel insights into how target selection supports decision making in uncertain environments.

α Power Modulation and Event-Related Slow Wave Provide Dissociable Correlates of Visual Working Memory.

Our work demonstrates that there exist event-related potential and oscillatory correlates of visual working memory (VWM) capacity even in the absence of task-irrelevant distractors. This clearly shows that the two neural correlates are directly linked to maintenance of task-relevant information rather than filtering of task-irrelevant information. Furthermore, we found that these two correlates show differential temporal characteristics. These results are inconsistent with proposals that the two neural correlates are byproducts of asymmetric α power suppression and indicate that they reflect dissociable neural mechanisms subserving VWM.

Attentional capture during attentional awakening.

We investigated whether attentional set is available at the beginning of a trial or whether it develops gradually within a trial. Thus, we manipulated the time from the onset of a trial to a target and observers' search strategy. We also observed the effect of the presence or absence of distractors as an index of the temporal development of attentional set. Participants identified a target letter embedded in a stream of rapidly presented nontargets while ignoring peripheral distractors. Baseline accuracy when no peripheral distractor was presented increased as the target appeared later in the stream, suggesting attentional awakening. Identification accuracy was impaired by the presence of peripheral distractors (i.e., attentional capture) early in the stream only when observers adopted the feature search mode. The magnitude of attentional capture increased over the course of the first 1,000 ms of a trial under the singleton detection and feature search modes. These results suggest that singleton detection mode requires time for a bottom-up signal to be effective in capturing attention, whereas the feature search mode does not require such a warm-up period to be effective and is available from the beginning of viewing the stream.

Perception of temporal order is impaired during the time course of the attentional blink.

Identification accuracy for the second of two target (T2) is impaired when presented shortly after the first (T1). Does this attentional blink (AB) also impair the perception of the order of presentation? In four experiments, three letter targets (T1, T2, T3) were inserted in a stream of digit distractors displayed in rapid serial visual presentation (RSVP), with T3 always presented directly after T2. The T1-T2 lag was varied to assess the perception of T2-T3 temporal order throughout the period of the AB. Factorial manipulation of the presence or absence of distractors before T1 and between T1 and T2 had similar effects on accuracy and on perception of temporal order. It is important to note that perception of temporal order suffered even when accuracy was unimpaired. This pattern of results is consistent with prior-entry theories of the perception of temporal order but not with episodic-integration theories. Simulations based on the Episodic Simultaneous Type, Serial Token (eSTST) model (Wyble, Bowman, & Nieuwenstein, 2009) provided excellent fits to the data except for the condition in which no distractors were presented in the RSVP stream.