Dual-target search for high and low prevalence X-ray threat targets

Recent studies have shown that the prevalence of target presentation in visual search has an impact on target detection rates, and also that searching for two targets leads to a decrement in performance (the “dual-target cost”). In the present experiments, we added to previous work that has examined the interaction between the prevalence effect and dual-target cost, and also to previous work that has examined a full range of prevalence levels. We found no interaction between the dual-target cost and prevalence effect, though the response criterion in dual-target search did interact with target prevalence in an unexpected manner. Furthermore, we detected anasymmetry in the prevalence effect: It was more marked for high than low prevalence. Implications for real-world tasks are discussed.     

Leader-focused search: The impact of an emerging preference on information search

This article examines the influence an emerging preference (i.e., a leader) has on predecisional information search. We explore two possibilities. First, decision makers may seek information they expect will support their leader (leader-supporting search). Second, decision makers may seek information about their leader, irrespective of the expected valence of the information (leader-focused search). Across various studies, product domains and experimental designs, we consistently find that decision makers engage in leader-focused search, not leader-supporting search. We also find that leader-focused search can steer decision makers towards information sources that are less important, less credible, and objectively suboptimal.     

The consequence of a limited-capacity short-term memory on repeated visual search

ABSTRACT

When participants search the same letter display repeatedly for different targets we might expect performance to improve on each subsequent search as they memorize characteristics of the display. However, here we find that search performance improved from a first search to a second search but not for a third search of the same display. This is predicted by a simple model that supports search with only a limited capacity short-term memory for items in the display. To support this model we show that a short-term memory recency effect is present in both the second and the third search. The magnitude of these effects is the same in both searches and as a result there is no additional benefit from the second to the third search.     

The impact of risk and affect on information search efficiency

We develop and test a theoretical framework of the joint influence of risk and affect on information search efficiency. Our framework proposes that information search is less efficient (i.e., less strategic) when risk is high, versus low. It further proposes that the influences of positive and negative affect on search efficiency are asymmetric and depend on the level of risk. Negative affect improves search efficiency when risk is high, but not when it is low. Positive affect degrades search efficiency when risk is low, but not when it is high. We find results consistent with our framework in two experiments. We discuss implications for affect research and for decision making in risky contexts, including financial statement auditing.     

Visual search for drowning swimmers: Investigating the impact of lifeguarding experience

How does domain expertise influence dynamic visual search? Previous studies of visual search often use abstract search arrays that are devoid of applied context, with comparatively few studies exploring applied naturalistic and dynamic settings. The current research adds to this literature by examining lifeguard drowning‐detection across two studies using naturalistic, dynamic search tasks. Behavioural responses and eye‐movement data were recorded as participants watched staged video clips and attempted to identify if a swimmer was drowning. The results demonstrate lifeguard superiority in response times to drowning events, compared to non‐lifeguards. No differences between lifeguard and non‐lifeguard eye‐movements were noted however. This suggests that the experiential benefit in response times results from other underlying processes, rather than any scanning benefits. This research highlights the complex nature of naturalistic and dynamic searches, while demonstrating the robust nature of simulated videos in producing experience effects in visual search.     

The properties of object representations constructed during visual search in natural scenes

To investigate properties of object representations constructed during a visual search task, we manipulated the proportion of trials/task within a block: In a search-frequent block, 80% of trials were search tasks; remaining trials presented a memory task; in a memory-frequent block, this proportion was reversed. In the search task, participants searched for a toy car (Experiments 1 and 2) or a T-shape object (Experiment 3). In the memory task, participants had to memorize objects in a scene. Memory performance was worse in the search-frequent block than in the memory-frequent block in Experiments 1 and 3, but not in Experiment 2 (token change in Experiment 1; type change in Experiments 2 and 3). Experiment 4 demonstrated that lower performance in the search-frequent block was not due to eye-movement behaviour. Results suggest that object representations constructed during visual search are different from those constructed during memorization and they are modulated by type of target.     

The types of stimuli loaded in memory can modulate its effects on visual search

The effects of memory load in visual search (VS) have shown a diversity of results from the absence through beneficial and detrimental effects of a concurrent memory load in VS performance. One of the hypotheses intended to explain the heterogeneity of results follows the idea proposed by certain models in the context of VS that the contents of working memory (WM) can modulate the attentional processes involved in VS (Desimone & Duncan, 1995; Duncan & Humphreys, 1989). In four experiments, we manipulated the similarity of information maintained in WM and those materials playing the role of target and distractors in the VS task. The results showed a beneficial effect in the first two experiments, where the materials in WM matched the target in VS. However, when they matched the distractors in the attentional task there is no effect in the slope of the search function. Present results strengthen those theories supporting that visual working memory is fractionated to allow for maintenance of items not essential to the attentional task (Downing & Dodds, 2004).     

The development of visual short-term memory for multifeature items during middle childhood

Visual short-term memory (VSTM) research suggests that the adult capacity is limited to three or four multifeature object representations. Despite evidence supporting a developmental increase in capacity, it remains unclear what the unit of capacity is in children. The current study employed the change detection paradigm to investigate both the capacity and nature of the representations of VSTM in 7-year-olds, 10-year-olds, and adults. Two experimental conditions were used to compare memory performance for single-feature objects with that for multifeature objects. Results provided further and more convincing evidence for a developmental increase in VSTM. Furthermore, the “loading up” of features in the multifeature condition was found to incur no significant performance deficit in all age groups. These findings are explained in terms of a developmental increase in the number of integrated multifeature object representations in VSTM.     

Limitations of perceptual segmentation on contextual cueing in visual search

In visual search, detection of a target in a repeated layout is faster than search within a novel arrangement, demonstrating that contextual invariances can implicitly guide attention to the target location (“contextual cueing”; Chun & Jiang, 1998). Here, we investigated how display segmentation processes influence contextual cueing. Seven experiments showed that grouping by colour and by size can considerably reduce contextual cueing. However, selectively attending to a relevant subgroup of items (that contains the target) preserved context-based learning effects. Finally, the reduction of contextual cueing by means of grouping affected both the latent learning and the recall of display layouts. In sum, all experiments show an influence of grouping on contextual cueing. This influence is larger for variations of spatial (as compared to surface) features and is consistent with the view that learning of contextual relations critically interferes with processes that segment a display into segregated groups of items.     

The effect of inducing panic search on the detection of fear-relevant and neutral images

Panic search occurs when the presentation of a fearful facial expression precue, prior to a search display, improves target detection relative to when neutral and positive expressions are used. In the present study, fearful and neutral expressions acted as precues and targets were images of either neutral or threatening animals. It was predicted that detection of a threatening image following a fearful precue would be particularly facilitated. In a first experiment, target detection was better when targets were threatening than neutral, but the predicted cue enhancement did not occur. In a second experiment, when cue type was blocked, participants were particularly facilitated in responding to threatening targets following fearful precues. It is concluded that consistent and repeated exposure to threatening facial expression results in a generalized increase in processing efficiency and that such a state induces a particular facilitation in responding in the presence of threatening targets.     

The effect of spatial frequency information and visual similarity in threat detection

In the current research, we sought to examine the role of spatial frequency on the detection of threat using a speeded visual search paradigm. Participants searched for threat-relevant (snakes or spiders) or non-threat-relevant (frogs or cockroaches) targets in an array of neutral (flowers or mushrooms) distracters, and we measured search performance with images filtered to contain different levels (high and low) of spatial frequency information. The results replicate previous work demonstrating more rapid detection of threatening versus non-threatening stimuli [e.g. LoBue, V. & DeLoache, J. S. (2008). Detecting the snake in the grass: Attention to fear-relevant stimuli by adults and young children. Psychological Science, 19, 284–289. doi:10.1111/j.1467-9280.2008.02081.x]. Most importantly, the results suggest that low spatial frequency or relatively coarse levels of visual information is sufficient for the rapid and accurate detection of threatening stimuli. Furthermore, the results also suggest that visual similarity between the stimuli used in the search tasks plays a significant role in speeded detection. The results are discussed in terms of the theoretical implications for the rapid detection of threat and methodological implications for properly accounting for similarity between the stimuli in visual search studies.     

Visual search for emotional expressions: Effect of stimulus set on anger and happiness superiority

Prior reports of preferential detection of emotional expressions in visual search have yielded inconsistent results, even for face stimuli that avoid obvious expression-related perceptual confounds. The current study investigated inconsistent reports of anger and happiness superiority effects using face stimuli drawn from the same database. Experiment 1 excluded procedural differences as a potential factor, replicating a happiness superiority effect in a procedure that previously yielded an anger superiority effect. Experiments 2a and 2b confirmed that image colour or poser gender did not account for prior inconsistent findings. Experiments 3a and 3b identified stimulus set as the critical variable, revealing happiness or anger superiority effects for two partially overlapping sets of face stimuli. The current results highlight the critical role of stimulus selection for the observation of happiness or anger superiority effects in visual search even for face stimuli that avoid obvious expression related perceptual confounds and are drawn from a single database.     

Task-dependent sensitisation of perceptual and semantic processing during visual search for words

Two experiments examined the impact of task-set on people's use of the visual and semantic features of words during visual search. Participants' eye movements were recorded while the distractor words were manipulated. In both experiments, the target word was either given literally (literal task) or defined by a semantic clue (categorical task). According to Kiefer and Martens, participants should preferentially use either the visual or semantic features of words depending on their relevance for the task. This assumption was partially supported. As expected, orthographic neighbours of the target word attracted participants' attention more and took longer to reject, once fixated, during the literal task. Conversely, semantic associates of the target word took longer to reject during the categorical task. However, they did not attract participants' attention more than in the literal task. This unexpected finding is discussed in relation to the processing of words in the peripheral visual field.     

The effect of face inversion on the detection of emotional faces in visual search

Past literature has indicated that face inversion either attenuates emotion detection advantages in visual search, implying that detection of emotional expressions requires holistic face processing, or has no effect, implying that expression detection is feature based. Across six experiments that utilised different task designs, ranging from simple (single poser, single set size) to complex (multiple posers, multiple set sizes), and stimuli drawn from different databases, significant emotion detection advantages were found for both upright and inverted faces. Consistent with past research, the nature of the expression detection advantage, anger superiority (Experiments 1, 2 and 6) or happiness superiority (Experiments 3, 4 and 5), differed across stimulus sets. However both patterns were evident for upright and inverted faces. These results indicate that face inversion does not interfere with visual search for emotional expressions, and suggest that expression detection in visual search may rely on feature-based mechanisms.     

The brain's hemispheres and controlled search of the lexicon: evidence from fixated words and pseudowords

Difference between the brain's hemispheres in efficiency of intentional search of the mental lexicon with phonological, orthographic, and semantic strategies was investigated. Letter strings for lexical decision were presented at fixation, with a lateralized distractor to the LVF or RVF. Word results revealed that both hemispheres were capable of using each of the three strategies, but the right hemisphere had better baseline processing of orthography and was better at processing semantics. Pseudoword results supported the right hemisphere advantage for orthography and showed a left hemisphere advantage for phonology and assessment of possible semantic relationships. Taken together, the data support the idea that the right hemisphere uses orthography to make efficient decisions about novelty of an item, while the left engages in grapheme-to-phoneme conversion to test hypotheses about unfamiliar items. The convergence of data with previous research reveals that the procedure, as well as analyses of pseudowords, inform laterality research.     

最心安处是吾乡：本体安全感威胁对家乡品牌偏好的影响

全球化进程的加快和贸易战的发生让人们处于一种本体不安全的状态中,即人们的本体安全感受到了威胁。本文研究了消费者本体安全感威胁对家乡品牌偏好的影响。三项研究的结果表明,相比本体安全感没有受到威胁的个体,本体安全感受到威胁的个体对家乡品牌的偏好度更高,其中家乡依恋起到了中介作用。具体而言,本体安全感受到威胁的个体更倾向于依恋可以提供常规生活和构建个人身份的家乡,以此寻求本体安全感恢复,从而增加了对家乡品牌的偏好。实验结果还发现,自然栖息地情境展露在本体安全感威胁对家乡品牌偏好的作用中起到调节作用。具体而言,当展露于自然栖息地情境时,本体安全感受到威胁的个体能够通过对自然栖息地这一更广泛的地点依恋来对抗本体安全感威胁,不再需要寻求家乡依恋来缓解本体安全感威胁,从而使其在对家乡品牌和非家乡品牌的偏好上不再呈现出差异。本研究的发现丰富了现有本体安全感和品牌偏好的相关研究,为品牌提供了一种新的本土营销策略,具有丰富的理论贡献和管理启示。     

Incidental memory for parts of scenes from eye movements

Incidental memory for parts of scenes was examined in two search experiments and one memory control experiment. Eye movements were recorded during the search experiments and used to select gaze-contingent sections from search scenes for a surprise memory recognition task. Results from the recognition task showed incidental memory was better for sections viewed longer and with multiple fixations. Sections not fixated during search were still recognized above chance as well. Differences in sections did not affect memory performance in a control experiment when viewing time was held constant. These results show that memory for parts of scenes can occur incidentally during search and encoding of tested sections is better with longer viewing time and with multiple fixations.     

Frames of reference for the light-from-above prior in visual search and shape judgements

Faced with highly complex and ambiguous visual input, human observers must rely on prior knowledge and assumptions to efficiently determine the structure of their surroundings. One of these assumptions is the 'light-from-above' prior. In the absence of explicit light-source information, the visual system assumes that the light-source is roughly overhead. A simple, low-cost strategy would place this 'light-from-above' prior in a retinal frame of reference. A more complex, but optimal strategy would be to assume that the light-source is gravitationally up, and compensate for observer orientation. Evidence to support one or other strategy from psychophysics and neurophysiology has been mixed. This paper pits the gravitational and retinal frames against each other in two different visual tasks that relate to the light-from-above prior. In the first task, observers had to report the presence or absence of a target where distractors and target were defined purely by shading. In the second task, observers made explicit shape judgements of similar stimuli. The orientation of the stimuli varied across trials and the observer's head was fixed at 0, +/-45 or +/-60 degrees . In both tasks the retinal frame of reference dominated. Visual search behaviour with shape-from-shading stimuli (SFS) was modulated purely by stimulus orientation relative to the retina. However, the gravitational frame of reference had a significant effect on shape judgements, with a 30% correction for observer orientation. In other words, shading information is processed quite differently depending on the demands of the current task. When a 'quick and dirty' representation is required to drive fast, efficient search, that is what the visual system provides. In contrast, when the task is to explicitly estimate shape, extra processing to compensate for head orientation precedes the perceptual judgment. These results are consistent with current neurophysiological data on SFS if we re-frame compensation for observer orientation as a cue-combination problem.     

Relational property between head and eye regions is the primary determinant of the efficiency in search for a deviant gaze

The human visual system is extremely sensitive to the directions of the gazes of others. However, the mechanism underlying gaze direction perception has yet to be clarified. The primary aim of the present study is to investigate whether the relational property between the local eye region and other facial regions serves as the primary visual system cue in detecting a direct gaze. Our results showed that search efficiency was determined primarily by the gaze direction indicated by the relational property regardless of the direction indicated by the local feature information of the eye region; this was true even when the gaze directions indicated by these two types of information were conflicting. These results bolster the hypothesis that the human visual system primarily accesses socially meaningful information in searching for a deviant gaze.     

Selective exposure and decision framing: The impact of gain and loss framing on confirmatory information search after decisions

When people make decisions, they often prefer to receive information that supports rather than conflicts with their decision. To date, this effect has mainly been investigated in the context of decisions about gains, whereas decisions about losses have received less attention. Based on Prospect Theory, we expected information search to be differently affected by whether people previously have decided about gains or losses. Three studies have revealed that selectivity of information search is stronger after gain-framed rather than after loss-framed decision problems. An investigation of the underlying psychological processes revealed that gain decisions are made with increased subjective decision certainty (i.e. they are easier and less effortful to make), which in turn systematically increases confirmatory information search.