How Prevalent Is Object-Based Attention?

Previous research suggests that visual attention can be allocated to locations in space (space-based attention) and to objects (object-based attention). The cueing effects associated with space-based attention tend to be large and are found consistently across experiments. Object-based attention effects, however, are small and found less consistently across experiments. In three experiments we address the possibility that variability in object-based attention effects across studies reflects low incidence of such effects at the level of individual subjects. Experiment 1 measured space-based and object-based cueing effects for horizontal and vertical rectangles in 60 subjects comparing commonly used target detection and discrimination tasks. In Experiment 2 we ran another 120 subjects in a target discrimination task in which rectangle orientation varied between subjects. Using parametric statistical methods, we found object-based effects only for horizontal rectangles. Bootstrapping methods were used to measure effects in individual subjects. Significant space-based cueing effects were found in nearly all subjects in both experiments, across tasks and rectangle orientations. However, only a small number of subjects exhibited significant object-based cueing effects. Experiment 3 measured only object-based attention effects using another common paradigm and again, using bootstrapping, we found only a small number of subjects that exhibited significant object-based cueing effects. Our results show that object-based effects are more prevalent for horizontal rectangles, which is in accordance with the theory that attention may be allocated more easily along the horizontal meridian. The fact that so few individuals exhibit a significant object-based cueing effect presumably is why previous studies of this effect might have yielded inconsistent results. The results from the current study highlight the importance of considering individual subject data in addition to commonly used statistical methods.     

Labels Direct Infants’ Attention to Commonalities during Novel Category Learning

Recent studies have provided evidence that labeling can influence the outcome of infants’ visual categorization. However, what exactly happens during learning remains unclear. Using eye-tracking, we examined infants’ attention to object parts during learning. Our analysis of looking behaviors during learning provide insights going beyond merely observing the learning outcome. Both labeling and non-labeling phrases facilitated category formation in 12-month-olds but not 8-month-olds (Experiment 1). Non-linguistic sounds did not produce this effect (Experiment 2). Detailed analyses of infants’ looking patterns during learning revealed that only infants who heard labels exhibited a rapid focus on the object part successive exemplars had in common. Although other linguistic stimuli may also be beneficial for learning, it is therefore concluded that labels have a unique impact on categorization.     

Do Singing Rock Hyraxes Exploit Conspecific Calls to Gain Attention?

Signal detection theory predicts that signals directed at distant or busy receivers in noisy backgrounds will begin with an alert component, in order to draw attention. Instead of an alert component, however, animals could get the same effect by using an external stimulus. Here we combined observations of free-living rock hyraxes (Procavia capensis) with playback experiments to elucidate the circumstances under which males begin singing. We show that males sing following hyrax pup screams, which elicit a strong response from hyraxes within hearing distance, which are potential receivers. We hypothesize that singers enhance their singing display by exploiting the rarely emitted pup screams. To our knowledge, our findings are the first indication that animals may enhance signal reception by exploiting conspecifics' signals and the differential attention to these signals. We suggest that the utilization of external stimuli by signalers may be widespread, as an adaptive strategy for communication in complex environments.     

Stay Tuned: What Is Special About Not Shifting Attention?

Background

When studying attentional orienting processes, brain activity elicited by symbolic cue is usually compared to a neutral condition in which no information is provided about the upcoming target location. It is generally assumed that when a neutral cue is provided, participants do not shift their attention. The present study sought to validate this assumption. We further investigated whether anticipated task demands had an impact on brain activity related to processing symbolic cues.

Methodology/Principal Findings

Two experiments were conducted, during which event-related potentials were elicited by symbolic cues that instructed participants to shift their attention to a particular location on a computer screen. In Experiment 1, attention shift-inducing cues were compared to non-informative cues, while in both conditions participants were required to detect target stimuli that were subsequently presented at peripheral locations. In Experiment 2, a non-ambiguous “stay-central” cue that explicitly required participants not to shift their attention was used instead. In the latter case, target stimuli that followed a stay-central cue were also presented at a central location. Both experiments revealed enlarged early latency contralateral ERP components to shift-inducing cues compared to those elicited by either non-informative (exp. 1) or stay-central cues (exp. 2). In addition, cueing effects were modulated by the anticipated difficulty of the upcoming target, particularly so in Experiment 2. A positive difference, predominantly over the posterior contralateral scalp areas, could be observed for stay-central cues, especially for those predicting that the upcoming target would be easy. This effect was not present for non-informative cues.

Conclusions/Significance

We interpret our result in terms of a more rapid engagement of attention occurring in the presence of a more predictive instruction (i.e. stay-central easy target). Our results indicate that the human brain is capable of very rapidly identifying the difference between different types of instructions.     

Do American Crows Pay Attention to Human Gaze and Facial Expressions?

Interactions between species can lead to the evolution of interspecific communication. Non‐verbal communication by humans, both intentional and unintentional, can be interpreted by other species. We tested whether American crows (Corvus brachyrhynchos) were sensitive to human facial features under field conditions by comparing flight initiation distances and urgency of escape behavior to human approaches varying in eye contact and facial expression. We first examined whether crows distinguish between an approaching human who is directly gazing at them and a human approaching them with an averted gaze. In a second experiment, we tested whether crows differentiate a smiling from scowling human approaching them with direct or averted gaze. In the first experiment, we found that crows fled sooner and more urgently when humans were directly gazing at them. Similarly, in the second experiment, crows responded sooner to a direct vs. averted gaze; however, they did not react differently to varying human facial expressions. We suggest that crows use human gaze as a reliable visual cue compared with facial expressions when making decisions about responding to approaching humans. This is the first study to show that a wild corvid species changes its behavior based on human gaze, possibly representing an adaptation to living in human‐dominated urban areas and suggesting crows might perceive human intention by this visual cue.     

Reactivity of θ and α EEG Frequency Bands in Voluntary Attention in Junior Schoolchildren

Spatiotemporal organization of rhythmic and EEG components was studied by means of spectral-correlation analysis in seven- to eight-year-old children (n = 18) during anticipatory selective attention to sensory tactile and auditory stimuli. The topography of changes in coherence of the oscillations suggests that functional assemblies formed on the basis of the rhythm are modality-specific. Their centers are localized in respective sensory-specific cortical regions (central areas of both hemispheres during tactile attention and temporal areas during auditory attention). The functional integration on the basis of the rhythm is represented in both hemispheres by functional associations of the temporal, frontal, and (to a lesser extent) posterior associative areas independently of the modality of a relevant signal. Both types of the functional integration are significant for a correct solution of a perceptive task. The proposition that the cooperation of the - and systems in neuronal organization of voluntary attention ensure, respectively, its informational and motivational aspects.     

Minds “At Attention”: Mindfulness Training Curbs Attentional Lapses in Military Cohorts

We investigated the impact of mindfulness training (MT) on attentional performance lapses associated with task-unrelated thought (i.e., mind wandering). Periods of persistent and intensive demands may compromise attention and increase off-task thinking. Here, we investigated if MT may mitigate these deleterious effects and promote cognitive resilience in military cohorts enduring a high-demand interval of predeployment training. To better understand which aspects of MT programs are most beneficial, three military cohorts were examined. Two of the three groups were provided MT. One group received an 8-hour, 8-week variant of Mindfulness-based Mind Fitness Training (MMFT) emphasizing engagement in training exercises (training-focused MT, n = 40), a second group received a didactic-focused variant emphasizing content regarding stress and resilience (didactic-focused MT, n = 40), and the third group served as a no-training control (NTC, n = 24). Sustained Attention to Response Task (SART) performance was indexed in all military groups and a no-training civilian group (CIV, n = 45) before (T1) and after (T2) the MT course period. Attentional performance (measured by A’, a sensitivity index) was lower in NTC vs. CIV at T2, suggesting that performance suffers after enduring a high-demand predeployment interval relative to a similar time period of civilian life. Yet, there were significantly fewer performance lapses in the military cohorts receiving MT relative to NTC, with training-focused MT outperforming didactic-focused MT at T2. From T1 to T2, A’ degraded in NTC and didactic-focused MT but remained stable in training-focused MT and CIV. In sum, while protracted periods of high-demand military training may increase attentional performance lapses, practice-focused MT programs akin to training-focused MT may bolster attentional performance more than didactic-focused programs. As such, training-focused MT programs should be further examined in cohorts experiencing protracted high-demand intervals.     

Effect of Biofeedback Training of Sensorimotor and β1EEG Rhythms on Attention Parameters

The effects of the EEG–biofeedback (EEG–BFB) procedure, aimed at increasing the sensorimotor (12–15 Hz) and (15–18 Hz) rhythms on the psychological and electrophysiological parameters of attention, were studied using the methods of scalp recording of evoked potentials in the bistimulus paradigm Go/No–Go and a psychological attention test (Test of Variables of Attention; TOVA). Twenty-five children with attention disorders were included in the study. EEG–BFB sessions significantly improved the attention, behavior, and school study results in 19 (76%) children. In these cases, a significant increase in the amplitude of the inhibitory component in the frontocentral leads and improvement of the TOVA parameters were found.     

“Did You Call Me?” 5-Month-Old Infants Own Name Guides Their Attention

An infant's own name is a unique social cue. Infants are sensitive to their own name by 4 months of age, but whether they use their names as a social cue is unknown. Electroencephalogram (EEG) was measured as infants heard their own name or stranger's names and while looking at novel objects. Event related brain potentials (ERPs) in response to names revealed that infants differentiate their own name from stranger names from the first phoneme. The amplitude of the ERPs to objects indicated that infants attended more to objects after hearing their own names compared to another name. Thus, by 5 months of age infants not only detect their name, but also use it as a social cue to guide their attention to events and objects in the world.     

Is Attention Based on Spatial Contextual Memory Preferentially Guided by Low Spatial Frequency Signals?

A popular model of visual perception states that coarse information (carried by low spatial frequencies) along the dorsal stream is rapidly transmitted to prefrontal and medial temporal areas, activating contextual information from memory, which can in turn constrain detailed input carried by high spatial frequencies arriving at a slower rate along the ventral visual stream, thus facilitating the processing of ambiguous visual stimuli. We were interested in testing whether this model contributes to memory-guided orienting of attention. In particular, we asked whether global, low-spatial frequency (LSF) inputs play a dominant role in triggering contextual memories in order to facilitate the processing of the upcoming target stimulus. We explored this question over four experiments. The first experiment replicated the LSF advantage reported in perceptual discrimination tasks by showing that participants were faster and more accurate at matching a low spatial frequency version of a scene, compared to a high spatial frequency version, to its original counterpart in a forced-choice task. The subsequent three experiments tested the relative contributions of low versus high spatial frequencies during memory-guided covert spatial attention orienting tasks. Replicating the effects of memory-guided attention, pre-exposure to scenes associated with specific spatial memories for target locations (memory cues) led to higher perceptual discrimination and faster response times to identify targets embedded in the scenes. However, either high or low spatial frequency cues were equally effective; LSF signals did not selectively or preferentially contribute to the memory-driven attention benefits to performance. Our results challenge a generalized model that LSFs activate contextual memories, which in turn bias attention and facilitate perception.     

Oculomotor Examination of the Weapon Focus Effect: Does a Gun Automatically Engage Visual Attention?

Background

A person is less likely to be accurately remembered if they appear in a visual scene with a gun, a result that has been termed the weapon focus effect (WFE). Explanations of the WFE argue that weapons engage attention because they are unusual and/or threatening, which causes encoding deficits for the other items in the visual scene. Previous WFE research has always embedded the weapon and nonweapon objects within a larger context that provides information about an actor''s intention to use the object. As such, it is currently unknown whether a gun automatically engages attention to a greater extent than other objects independent of the context in which it is presented.

Method

Reflexive responding to a gun compared to other objects was examined in two experiments. Experiment 1 employed a prosaccade gap-overlap paradigm, whereby participants looked toward a peripheral target, and Experiment 2 employed an antisaccade gap-overlap paradigm, whereby participants looked away from a peripheral target. In both experiments, the peripheral target was a gun or a nonthreatening object (i.e., a tomato or pocket watch). We also controlled how unexpected the targets were and compared saccadic reaction times across types of objects.

Results

A gun was not found to differentially engage attention compared to the unexpected object (i.e., a pocket watch). Some evidence was found (Experiment 2) that both the gun and the unexpected object engaged attention to a greater extent compared the expected object (i.e., a tomato).

Conclusion

An image of a gun did not engage attention to a larger extent than images of other types of objects (i.e., a pocket watch or tomato). The results suggest that context may be an important determinant of WFE. The extent to which an object is threatening may depend on the larger context in which it is presented.     

Are you Paying Attention? Female Wolf Spiders Increase Dragline Silk Advertisements When Males do not Court

Females of many spider species invest in chemical advertisements to attract males, yet variation in investment relative to the presence or quality of males remains poorly understood. Males of the wolf spider Pardosa milvina court females longer and more intensively when in contact with female silk and also court more intensively when encountering silk from virgin rather than mated females; therefore, females may use silk as a medium to advertise their receptivity to mate. We estimated female investment in advertisements by measuring variation in the quantity and type of silk deposited by females in the presence or absence of males and among males that varied in their courtship intensity. We measured dragline silk, cord silk, and attachment disk deposition from females on gridded sheets of paper in response to four stimuli over a 30‐min period (n = 39/treatment): (1) an intensively (high) courting male with access to female silk, (2) a weakly courting or non‐courting male (low) without access to female silk, (3) no male present, but female silk present (silk control), and (4) no stimulus present (control). Females produced significantly more dragline silk and significantly less cord silk in the presence of low‐courting males compared to any other treatment, but we found no difference in attachment disk deposition across treatments. Our results suggest that females invest more heavily in dragline deposition when encountering low‐courting males. Additional studies are necessary to determine the relative role of different silk types in male–female sexual communication.     

What Time Periods of the Day Are Concerning for Parents of Children with Attention Deficit Hyperactivity Disorder?

Background/Aim

The questionnaire-children with difficulties (QCD) is a parent-assessed questionnaire designed to evaluate a child’s difficulties in functioning during specific time periods of the day. In this study, the QCD was applied to determine the time periods of the day that are concerning for the parents of children with attention deficit hyperactivity disorder (ADHD). The results were compared with those for a community sample.

Methods

Elementary and junior high school students with ADHD (243 boys, 55 girls) and a community sample of children (518 boys, 618 girls) were enrolled in this study. Their behaviors were assessed by the QCD, the ADHD-rating scale (ADHD-RS), and the Oppositional Defiant Behavior Inventory (ODBI). The effects of gender (boy/girl) and diagnosis (ADHD/community sample) on the total QCD score were analyzed across each school grade (elementary/junior high school). Correlation coefficients between QCD and ADHD-RS/ODBI scores were analyzed.

Results

The QCD score for the ADHD group was significantly lower than that for the community sample (P < 0.001). There were significantly strong correlations between “evening” and ADHD-RS and ODBI scores for all children with ADHD (r > 0.41, P < 0.001) and between “night” and inattention and oppositional symptoms for the girls with ADHD (r > 0.40, P < 0.001).

Conclusions

Parents reported that children with ADHD faced greater difficulties in completing basic daily activities compared with the community controls, particularly in the evening. Furthermore, these difficulties were related to the severity of ADHD symptoms. The parents’ perceptions depended on the gender, ADHD and oppositional symptoms, and the time period of the day. This study determined that children with ADHD face greater difficulties in daily functioning compared with community sample children, that these difficulties are time-dependent, and that these difficulties were particularly experienced in the evening.     

Can Attention Be Confined to Just Part of a Moving Object? Revisiting Target-Distractor Merging in Multiple Object Tracking

While it was initially thought that attention was space-based, more recent work has shown that attention can also be object-based, in that observers find it easier to attend to different parts of the same object than to different parts of different objects. Such studies have shown that attention more easily spreads throughout an object than between objects. However, it is not known to what extent attention can be confined to just part of an object and to what extent attending to part of an object necessarily causes the entire object to be attended. We have investigated this question in the context of the multiple object tracking paradigm in which subjects are shown a scene containing a number of identical moving objects and asked to mentally track a subset of them, the targets, while not tracking the remainder, the distractors. Previous work has shown that joining each target to a distractor by a solid connector so that each target-distractor pair forms a single physical object, a technique known as target-distractor merging, makes it hard to track the targets, suggesting that attention cannot be restricted to just parts of objects. However, in that study the target-distractor pairs continuously changed length, which in itself would have made tracking difficult. Here we show that it remains difficult to track the targets even when the target-distractor pairs do not change length and even when the targets can be differentiated from the connectors that join them to the distractors. Our experiments suggest that it is hard to confine attention to just parts of objects, at least in the case of moving objects.     

Is Visual Selective Attention in Deaf Individuals Enhanced or Deficient? The Case of the Useful Field of View

Background

Early deafness leads to enhanced attention in the visual periphery. Yet, whether this enhancement confers advantages in everyday life remains unknown, as deaf individuals have been shown to be more distracted by irrelevant information in the periphery than their hearing peers. Here, we show that, in a complex attentional task, a performance advantage results for deaf individuals.

Methodology/Principal Findings

We employed the Useful Field of View (UFOV) which requires central target identification concurrent with peripheral target localization in the presence of distractors – a divided, selective attention task. First, the comparison of deaf and hearing adults with or without sign language skills establishes that deafness and not sign language use drives UFOV enhancement. Second, UFOV performance was enhanced in deaf children, but only after 11 years of age.

Conclusions/Significance

This work demonstrates that, following early auditory deprivation, visual attention resources toward the periphery slowly get augmented to eventually result in a clear behavioral advantage by pre-adolescence on a selective visual attention task.     

To See or Not to See: Do Front of Pack Nutrition Labels Affect Attention to Overall Nutrition Information?

Background

Front of pack (FOP) nutrition labels are concise labels located on the front of food packages that provide truncated nutrition information. These labels are rapidly gaining prominence worldwide, presumably because they attract attention and their simplified formats enable rapid comparisons of nutritional value.

Methods

Eye tracking was conducted as US consumers interacted with actual packages with and without FOP labels to (1) assess if the presence of an FOP label increases attention to nutrition information when viewers are not specifically tasked with nutrition-related goals; and (2) study the effect of FOP presence on consumer use of more comprehensive, traditional nutrition information presented in the Nutritional Facts Panel (NFP), a mandatory label for most packaged foods in the US.

Results

Our results indicate that colored FOP labels enhanced the probability that any nutrition information was attended, and resulted in faster detection and longer viewing of nutrition information. However, for cereal packages, these benefits were at the expense of attention to the more comprehensive NFP. Our results are consistent with a potential short cut effect of FOP labels, such that if an FOP was present, participants spent less time attending the more comprehensive NFP. For crackers, FOP labels increased time spent attending to nutrition information, but we found no evidence that their presence reduced the time spent on the nutrition information in the NFP.

Conclusions

The finding that FOP labels increased attention to overall nutrition information by people who did not have an explicit nutritional goal suggests that these labels may have an advantage in conveying nutrition information to a wide segment of the population. However, for some food types this benefit may come with a short-cut effect; that is, decreased attention to more comprehensive nutrition information. These results have implications for policy and warrant further research into the mechanisms by which FOP labels impact use of nutrition information by consumers for different foods.     

Are Centrally Displaying Males Always the Centre of Female Attention? Acoustic Display Position and Female Choice in a Lek Mating Subterranean Insect

Several conceptual models seek to explain patterns of male display and factors that influence female mate choice in lek mating systems. The central advantage model predicts that males displaying at or near the lek centre should be more attractive to females than are males positioned along the lek periphery. Females may exhibit biases toward these centrally displaying males based on either spatial or display‐related cues. We tested the prediction of the central advantage model in investigating the importance of male display position in the subterranean and lek mating prairie mole cricket (Gryllotalpa major). Gryllotalpa major males form mating aggregations in the early spring and produce an acoustic advertisement signal from a constructed calling chamber at the soil surface. Pair formation occurs in the calling chamber, and males typically maintain these structures for the duration of the reproductive season. To assess whether G. major females exhibit a preference for males calling from centrally located acoustic burrows, we documented the spatial position and number of female attractions for all advertising males across the focal lek. Six spatial attributes related to display position were reduced using principal component analysis and examined for an association with male attractiveness. We found that in general, female attractions were distributed randomly across the lek; male attractiveness was not related to proximity to the lek centre nor to any factor associated with display position. The most highly attractive males, however, were located further from the lek centre and from nearest calling neighbours than other attractive males. Advertising males that segregate themselves within the aggregation and locate nearer the lek margin may gain a geometric advantage resulting in the increased probability of attracting a searching female.     

Molecular Assessment and Taxonomic Status of the Rapid Racerunner （Eremias velox complex） with Particular Attention to the Populations in Northwestern China

The rapid racerunner,Eremias velox,is a widely distributed lizard from the northern Caucasus across entire Central Asia eastward to China.It is increasingly common to accept E.velox as a species complex in its entire range.To date,published morphological and molecular systematic hypotheses of this complex are only partially congruent,and its taxonomic status and evolutionary history are still far from clear.The mitochondrial cytochrome b gene and12S rRNA sequences were used to evaluate the taxonomy of this complex,with particular attention to the phylogenetic placement of populations in northwestern China.Examination of the phylogenetic analyses recovers seven distinct,biogeographically discrete,and well-supported clades,revealing genetically identifiable populations corresponding to some previously morphology-defined subspecies.Chinese E.v.roborowskii appears to have split from other Central Asian rapid racerunner lizards well before differentiation occurred among the latter taxa.Specifically,we corroborate that there are two subspecies occurring in China,i.e.,E.v.velox and E.v.roborowskii.We recommend a novel subspecific status for the phenotypically and genetically distinct populations in southern Aral Sea region of Uzbekistan previously assigned to E.v.velox.Finally,each of the three independently evolving lineages from Iranian Plateau should be recognized as three species new to science under the general lineage concept.