The nature of the visual environment induces implicit biases during language-mediated visual search

Four eyetracking experiments examined whether semantic and visual-shape representations are routinely retrieved from printed word displays and used during language-mediated visual search. Participants listened to sentences containing target words that were similar semantically or in shape to concepts invoked by concurrently displayed printed words. In Experiment 1, the displays contained semantic and shape competitors of the targets along with two unrelated words. There were significant shifts in eye gaze as targets were heard toward semantic but not toward shape competitors. In Experiments 2–4, semantic competitors were replaced with unrelated words, semantically richer sentences were presented to encourage visual imagery, or participants rated the shape similarity of the stimuli before doing the eyetracking task. In all cases, there were no immediate shifts in eye gaze to shape competitors, even though, in response to the Experiment 1 spoken materials, participants looked to these competitors when they were presented as pictures (Huettig & McQueen, 2007). There was a late shape-competitor bias (more than 2,500 ms after target onset) in all experiments. These data show that shape information is not used in online search of printed word displays (whereas it is used with picture displays). The nature of the visual environment appears to induce implicit biases toward particular modes of processing during language-mediated visual search.     

Semantic facilitation with pictures and words

The present experiments explored the role of processing level and strategic factors in cross-form (word-picture and picture-word) and within-form (picture-picture and word-word) semantic facilitation. Previous studies have produced mixed results. The findings presented in this article indicate that semantic facilitation depends on the task and on the subjects' strategies. When the task required semantic processing of both picture and word targets (e.g., category verification), equivalent facilitation was obtained across all modality combinations. When the task required name processing (e.g., name verification, naming), facilitation was obtained for the picture targets. In contrast, with word targets, facilitation was obtained only when the situation emphasized semantic processing. The results are consistent with models that propose a common semantic representation for both picture and words but that also include assumptions regarding differential order of access to semantic and phonemic features for these stimulus modalities.     

The influence of an emotional processing strategy on visual threat detection by police trainees and officers

Threat detection is an important skill for police officers, but few studies have examined the impact of processing strategies on this ability. The first aim of our study was to compare the visual detection of threatening and neutral targets in 38 police trainees and 53 police officers. The other aims were to examine the effect of emotional or semantic strategies on this process and the effect of psychopathological symptoms. In a visual search task, participants had to detect a threatening or neutral target among neutral distractors. Participants answered a question used to induce a more emotional or semantic processing strategy. Results revealed that threatening targets were detected faster than neutral ones. This effect was enhanced with an emotional processing strategy but unaffected by symptoms. Processing strategy also had led to faster reaction time overall. This study shows that inducing processing strategies can influence threat detection in police trainees and officers.     

Visual search with biological threat stimuli: accuracy, reaction times, and heart rate changes

Twenty-four participants were given a visual search task of deciding whether all the pictures in 3 x 3 search arrays contained a target picture from a deviant category, and heart rate was measured. The categories were snakes, spiders, flowers, and mushrooms. Shorter reaction times (RTs) were observed for fear-relevant (snake and spider) targets rather than for fear-irrelevant/neutral (flower and mushroom) targets. This difference was most pronounced for the participants presented with a gray-scale version of the search arrays. The 1st interbeat interval (IBI), after the search array onset, showed an effect of the target, whereas the 2nd IBI also showed an effect of the distractors. The results suggest that controlled processing of the task operates together with automatic processing.     

Semantic priming in visual word recognition: Activation blocking and domains of processing

The fact that letter search on a prime eliminates the typically robust semantic priming effect in lexical decision is often attributed to the “shallowness” of the prime-processing task. In three experiments we investigated this claim by using two different “shallow” prime-processing tasks: letter search and color identification. Consistent with previous reports, lexical decisions to semantically related targets were not facilitated when subjects searched the prime for a probe letter. In contrast, semantic priming was observed following a color discrimination task on the prime. We suggest that a levels-of-processing interpretation is not an adequate framework for understanding these data. Instead, a domain-specific processing account is offered in which explicit processing at the letter level (as in letter search) makes demands on resources (e.g., activation) that drives processing at the semantic level. This competition is resolved by establishing a temporary activation block at the lexical-semantic interface, which results in the elimination or attenuation of semantic priming. In contrast, global judgment of color is viewed as a domain that does not make demands on the resources that drive the visual word recognition machinery. There is therefore no need for an activation block, and semantic priming is not prevented.     

You’re looking for what? Comparing search for familiar,nameable objects to search for unfamiliar,novel objects

Searching for items in one’s environment often includes considerable reliance on semantic knowledge. The present study examines the importance of semantic information in visual and memory search, especially with respect to whether the items reside in long-term or working memory. In Experiment 1, participants engaged in hybrid visual memory search for items that were either highly familiar or novel. Importantly, the relatively large number of targets in this hybrid search task necessitated that targets be stored in some form of long-term memory. We found that search for familiar objects was more efficient than search for novel objects. In Experiment 2, we investigated search for familiar versus novel objects when the number of targets was low enough to be stored in working memory. We also manipulated how often participants in Experiment 2 were required to update their target (every trial vs. every block) in order to control for target templates that were stored in long-term memory as a result of repeated exposure over trials. We found no differences in search efficiency for familiar versus novel objects when templates were stored in working memory. Our results suggest that while semantic information may provide additional individuating features that are useful for object recognition in hybrid search, this information could be irrelevant or even distracting when searching for targets stored in working memory.     

Detecting conjunctions of color and form in parallel

Certain theories of visual attention assume that at least one processing stage must be serial when the target of search is defined as the conjunction of two or more separable features. To explain why conjunction-search response times do not always form linearly increasing functions of display size, recent versions of this general model have posited the existence of an early parallel process that guides the serial stage toward display elements that are likely targets. Other models have relaxed the seriality assumption, allowing for a limited number of parallel decisions. In the three experiments reported here, a redundant-target detection task was used with conjunctively defined targets and display sizes of two (Experiment 1), one or two (Experiment 2), and six (Experiment 3). In all three experiments, strong evidence for parallel processing was observed. The implications for models of elementary visual processes are discussed.     

Investigating spatial vision and dynamic attentional selection using a gaze-contingent multiresolutional display

This study examined spatial vision and attentional selection using a gaze-contingent multiresolutional display, with a dynamic, gaze-centered, high-resolution window and lower resolution periphery. Visual search times and eye movements from 15 participants in a 3 x 3 design (Window Radius x Peripheral Resolution) suggest that contrast sensitivity as a function of retinal eccentricity affects attentional selection and visual processing. Smaller windows led to longer search times and shorter saccades; lower peripheral resolution also shortened saccades (all ps < .05) as a result of avoiding fixating degraded areas. Fixation durations, although longer for smaller windows (p < .05), were unaffected by whether the next saccade went within or outside the window. These results are explained through (a) competition among potential saccade targets where above-threshold filtering reduces an object's relative salience and (b) generally disrupted visual processing.     

On the interaction between linguistic and pictorial systems in the absence of semantic mediation: Evidence from a priming paradigm

Use of the letter search task in the context of the priming paradigm has proved to be an invaluable tool for the investigation of the strategic control of processes involved in word recognition. In particular, previous findings that letter search on a prime word interferes with the priming of semantically/associatively related targets, but not with the priming of either identical or morphologically related targets, suggests that letter search may selectively interfere with semantic processing, leaving other levels of processing intact. In the present experiments, this investigation was extended by exploring the priming of pictures following letter search of either a same-concept word (repetition priming) or a semantically/associatively related word (semantic priming). There was significant repetition priming of picture categorization following both silent reading and letter search of the prime word (Experiments 1 and 2). In contrast, semantic priming of pictures was found only following silent reading of the prime; there was no semantic priming following letter search of the prime (Experiment 2). This pattern of results suggests that focusing attention at the letter level during prime processing selectively attenuates activation of the semantic system by the prime. It does not prevent the spread of activation between the lexical and pictogen levels of representation of a given concept.     

Priming effects in attentional gating

Three experiments were conducted to determine the effects of amount of prior target information (Experiment 1) and semantic priming (Experiment 2) in an attentional gating task. The goal was to determine some causes of the processing deficits commonly observed in perceiving successive visual stimuli. Items in a rapid serial visual presentation (RSVP) stream are subject to processing deficits before they are processed to the level of recognition (early selection) and after they have been recognized (late selection). Deficits in the former case presumably are due to an early filter that prevents complete recognition and semantic analysis, whereas deficits in the latter case arise from interference or response competition, producing forgetting among a set of recognized items. The semantic-priming effects found between a cue and a target (Experiment 2) and between two successive targets (Experiment 3) indicate that top-down processes can increase the subjective availability of related items. The results are consistent with the idea that most processing deficits observed in search through an RSVP sequence are due to limited capacity in our ability to form episodic representations of all the items in the sequence.     

Words,shape, visual search and visual working memory in 3‐year‐old children

Do words cue children's visual attention, and if so, what are the relevant mechanisms? Across four experiments, 3‐year‐old children (N = 163) were tested in visual search tasks in which targets were cued with only a visual preview versus a visual preview and a spoken name. The experiments were designed to determine whether labels facilitated search times and to examine one route through which labels could have their effect: By influencing the visual working memory representation of the target. The targets and distractors were pictures of instances of basic‐level known categories and the labels were the common name for the target category. We predicted that the label would enhance the visual working memory representation of the target object, guiding attention to objects that better matched the target representation. Experiments 1 and 2 used conjunctive search tasks, and Experiment 3 varied shape discriminability between targets and distractors. Experiment 4 compared the effects of labels to repeated presentations of the visual target, which should also influence the working memory representation of the target. The overall pattern fits contemporary theories of how the contents of visual working memory interact with visual search and attention, and shows that even in very young children heard words affect the processing of visual information.     

Morphological priming: the role of prime duration, semantic transparency, and affix position.

Patterns of facilitation in three lexical decision studies reveal several properties of morphologically complex words that influence processing. In one study, effects of morphological (VOWED-VOW) similarity are contrasted with effects of either semantic (PLEDGE-VOW) or orthographic (VOWEL-VOW) similarity at two prime durations to show the distinctiveness of morphological processing. In a second study, we compare morphologically complex forms that are semantically transparent (CASUALLY-CASUALNESS) with opaque forms (CASUALTY-CASUALNESS) and show that opaque relatives are more similar to VOWEL-VOW type pairs than to transparent relatives. In the third study, we examine facilitation for complex targets (CALCULATION) preceded by prefixed (MISCALCULATE) and suffixed (CALCULATOR) relatives and show that the position of the base morpheme influences processing under cross-modal but not under purely visual presentation conditions. Taken collectively, under comparable presentation conditions, semantic transparency but not base morpheme position constrains morphological processing.     

Word-Monitoring Tasks Interact with Levels of Representation During Speech Comprehension

Researchers frequently use data from monitoring tasks to argue that constraints on meaning facilitate lower-level processes. An alternate hypothesis is that the processing level that a monitoring task requires interacts with discourse-level processing. Subjects monitored spoken sentences for a synonym (semantic match), a nonsense word (phonological match), or a rhyme (phonologically and semantically constrained matching). The critical targets appeared at the beginning of the final clause in two-clause sentences that began with if, which signals a semantic analysis at the discourse level, or with though, which maintains a surface representation. Synonym-monitoring times were faster for if than for though, nonsense word-monitoring times were faster for though than for if, and rhyme-monitoring times did not differ for if and though. The results show that conjunctions influence how listeners allocate attention to semantic versus phonological information, implying that listeners form these kinds of information independently.     

比较视觉搜索任务的认知老化研究

本研究通过增加组成图片的图形数量和改变目标图形的特征,考察老年人和大学生在比较视觉搜索任务中的眼动特点和图形特征加工的优先性。结果表明与青年人相比,老年人在比较视觉搜索过程中总注视时间和注视次数增加,平均眼跳幅度减少,对目标刺激的注视时间增加。老年人和青年人在目标刺激的注视过程中都表现出图形维度数量的优先性,即表现为颜色和形状都不同的目标刺激注视时间最短,颜色不同和形状不同的目标刺激在注视时间上差异不显著。说明老年人在比较视觉搜索过程中存在认知老化,在图形特征加工的优先性上结果和青年人一致,以上结果与年龄和研究任务有关。     

Target self-relevance speeds visual search responses but does not improve search efficiency

ABSTRACT

In a variety of contexts, arbitrarily associating one’s self with a stimulus improves performance relative to stimuli that are not self-associated, implying enhanced processing of self-associated stimuli (“self-relevance” effects). Self-relevance has been proposed to influence diverse aspects of cognition, including the perceptual prioritization of self-relevant stimuli (“self-prioritization” effects). We sought to elucidate the mechanisms of self-prioritization by using a visual search paradigm. In three experiments, subjects learned two stimulus-label combinations (SELF and OTHER), and then searched for one of those stimuli (cued by the label) on each trial, with a variable number of distractors present on each trial. We hypothesized that, if self-relevance enhances the perceptual salience of the stimuli pre-attentively, then the self-relevance of a target should result in improved search efficiency. In three experiments using conjunction-defined (Experiments 1–2) and feature-defined (Experiment 3) targets, we found that self-relevant targets were associated with overall faster responses than non-self-relevant targets (an intercept effect). However, the slopes of the search size by reaction time (RT) function were never significantly different between the self-relevant and non-self-relevant conditions, counter to the hypothesis that self-prioritization is pre-attentive. These results constitute novel evidence that self-relevance affects visual search performance, but they also cast doubt on the possibility that self-relevance enhances the perceptual salience of a target in a manner similar to physical manipulations. We propose that the self-relevance of a stimulus alters processing only after the self-relevant item has been attended.     

Semantic priming is affected by real-time phonological competition: Evidence for continuous cascading systems

Lexical-semantic access is affected by the phonological structure of the lexicon. What is less clear is whether such effects are the result of continuous activation between lexical form and semantic processing or whether they arise from a more modular system in which the timing of accessing lexical form determines the timing of semantic activation. This study examined this issue using the visual world paradigm by investigating the time course of semantic priming as a function of the number of phonological competitors. Critical trials consisted of high or low density auditory targets (e.g., horse) and a visual display containing a target, a semantically related object (e.g., saddle), and two phonologically and semantically unrelated objects (e.g., chimney, bikini). Results showed greater magnitude of priming for semantically related objects of low than of high density words, and no differences for high and low density word targets in the time course of looks to the word semantically related to the target. This pattern of results is consistent with models of cascading activation, which predict that lexical activation has continuous effects on the level of semantic activation, with no delays in the onset of semantic activation for phonologically competing words.     

Goal-directed aiming under restricted viewing conditions with confirmatory sensory feedback

A substantial body of research has examined the speed-accuracy tradeoff captured by Fitts’ law, demonstrating increases in movement time that occur as aiming tasks are made more difficult by decreasing target width and/or increasing the distance between targets. Yet, serial aiming movements guided by internal spatial representations, rather than by visual views of targets have not been examined in this manner, and the value of confirmatory feedback via different sensory modalities within this paradigm is unknown. Here we examined goal-directed serial aiming movements (tapping back and forth between two targets), wherein targets were visually unavailable during the task. However, confirmatory feedback (auditory, haptic, visual, and bimodal combinations of each) was delivered upon each target acquisition, in a counterbalanced, within-subjects design. Each participant performed the aiming task with their pointer finger, represented within an immersive virtual environment as a 1 cm white sphere, while wearing a head-mounted display. Despite visual target occlusion, movement times increased in accordance with Fitts’ law. Though Fitts’ law captured performance for each of the sensory feedback conditions, the slopes differed. The effect of increasing difficulty on movement times was least influential in the haptic condition, suggesting more efficient processing of confirmatory haptic feedback during aiming movements guided by internal spatial representations.     

Hemispheric processing of lexical information in Chinese character recognition and its relationship to reading performance

Hemispheric predominance has been well documented in the visual perception of alphabetic words. However, the hemispheric processing of lexical information in Chinese character recognition and its relationship to reading performance are far from clear. In the divided visual field paradigm, participants were required to judge the orthography, phonology, or semantics of Chinese characters, which were presented randomly in the left or right visual field. The results showed a right visual field/left hemispheric superiority in the phonological judgment task, but no hemispheric advantage in the orthographic or semantic task was found. In addition, reaction times in the right visual field for phonological and semantic tasks were significantly correlated with the reading test score. These results suggest that both hemispheres involved in the orthographic and semantic processing of Chinese characters, and that the left lateralized phonological processing is important for Chinese fluent reading.     

Parallel pattern processing and visual agnosia.

A series of visual search experiments are reported examining pattern processing in a visual agnosic patient. We examined search for targets defined by: (I) the combination of their features relative to homogeneous distractors; (2) the combination of their features relative to heterogeneous distractors; and (3) a single feature difference relative to the distractors (their orientation). Normal subjects demonstrate evidence of spatially parallel search when combined-feature targets are detected against homogeneous distractors, and when targets are defined by a salient feature difference. There are non-linear effects of the number of distractors present, and absent responses can be as fast as present. In contrast, search times for combined-feature targets amongst heterogeneous distractors increase linearly with display size, with the slope for absent responses about twice that for present. The contrast between search for combined-feature targets amongst homogeneous and heterogeneous distractors can be attributed to the effects of grouping between distractors and between distractors and targets (Duncan & Humphreys, 1989, 1992; Humphreys & Muller, in press). Grouping between homogeneous distractors facilitates search. An agnosic patient, HJA, showed normal search functions for single-feature targets and for combined-feature targets amongst heterogeneous distractors. However, he was impaired at search for combined-feature targets amongst homogeneous distractors. This suggests that HJA is selectively impaired at grouping conjunctions of form features. The relations between HJA's agnosia and his problem in the parallel grouping of form conjunctions are discussed, as are the implications of the work for understanding normal vision.