Searching through the hierarchy: How level of target categorization affects visual search

Does the same basic-level advantage commonly observed in the categorization literature also hold for targets in a search task? We answered this question by first conducting a category verification task to define a set of categories showing a standard basic-level advantage, which we then used as stimuli in a search experiment. Participants were cued with a picture preview of the target or its category name at either superordinate, basic, or subordinate levels, then shown a target-present/absent search display. Although search guidance and target verification was best using pictorial cues, the effectiveness of the categorical cues depended on the hierarchical level. Search guidance was best for the specific subordinate-level cues, whereas target verification showed a standard basic-level advantage. These findings demonstrate different hierarchical advantages for guidance and verification in categorical search. We interpret these results as evidence for a common target representation underlying categorical search guidance and verification.     

Does conspicuity enhance distraction? Saliency and eye landing position when searching for objects

While visual saliency may sometimes capture attention, the guidance of eye movements in search is often dominated by knowledge of the target. How is the search for an object influenced by the saliency of an adjacent distractor? Participants searched for a target amongst an array of objects, with distractor saliency having an effect on response time and on the speed at which targets were found. Saliency did not predict the order in which objects in target-absent trials were fixated. The within-target landing position was distributed around a modal position close to the centre of the object. Saliency did not affect this position, the latency of the initial saccade, or the likelihood of the distractor being fixated, suggesting that saliency affects the allocation of covert attention and not just eye movements.     

Looking at anything that is green when hearing “frog”: How object surface colour and stored object colour knowledge influence language-mediated overt attention

Three eye-tracking experiments investigated the influence of stored colour knowledge, perceived surface colour, and conceptual category of visual objects on language-mediated overt attention. Participants heard spoken target words whose concepts are associated with a diagnostic colour (e.g., “spinach”; spinach is typically green) while their eye movements were monitored to (a) objects associated with a diagnostic colour but presented in black and white (e.g., a black-and-white line drawing of a frog), (b) objects associated with a diagnostic colour but presented in an appropriate but atypical colour (e.g., a colour photograph of a yellow frog), and (c) objects not associated with a diagnostic colour but presented in the diagnostic colour of the target concept (e.g., a green blouse; blouses are not typically green). We observed that colour-mediated shifts in overt attention are primarily due to the perceived surface attributes of the visual objects rather than stored knowledge about the typical colour of the object. In addition our data reveal that conceptual category information is the primary determinant of overt attention if both conceptual category and surface colour competitors are copresent in the visual environment.     

How preview space/time translates into preview cost/benefit for fixation durations during reading

Eye-movement control during reading depends on foveal and parafoveal information. If the parafoveal preview of the next word is suppressed, reading is less efficient. A linear mixed model (LMM) reanalysis of McDonald (2006) confirmed his observation that preview benefit may be limited to parafoveal words that have been selected as the saccade target. Going beyond the original analyses, in the same LMM, we examined how the preview effect (i.e., the difference in single-fixation duration, SFD, between random-letter and identical preview) depends on the gaze duration on the pretarget word and on the amplitude of the saccade moving the eye onto the target word. There were two key results: (a) The shorter the saccade amplitude (i.e., the larger preview space), the shorter a subsequent SFD with an identical preview; this association was not observed with a random-letter preview. (b) However, the longer the gaze duration on the pretarget word, the longer the subsequent SFD on the target, with the difference between random-letter string and identical previews increasing with preview time. A third pattern—increasing cost of a random-letter string in the parafovea associated with shorter saccade amplitudes—was observed for target gaze durations. Thus, LMMs revealed that preview effects, which are typically summarized under “preview benefit”, are a complex mixture of preview cost and preview benefit and vary with preview space and preview time. The consequence for reading is that parafoveal preview may not only facilitate, but also interfere with lexical access.     

Naming fluency in dyslexic and nondyslexic readers: Differential effects of visual crowding in foveal,parafoveal, and peripheral vision

Reading fluency is often indexed by performance on rapid automatized naming (RAN) tasks, which are known to reflect speed of access to lexical codes. We used eye tracking to investigate visual influences on naming fluency. Specifically, we examined how visual crowding affects fluency in a RAN-letters task on an item-by-item basis, by systematically manipulating the interletter spacing of items, such that upcoming letters in the array were viewed in the fovea, parafovea, or periphery relative to a given fixated letter. All lexical information was kept constant. Nondyslexic readers’ gaze durations were longer in foveal than in parafoveal and peripheral trials, indicating that visual crowding slows processing even for fluent readers. Dyslexics’ gaze durations were longer in foveal and parafoveal trials than in peripheral trials. Our results suggest that for dyslexic readers, influences of crowding on naming speed extend to a broader visual span (to parafoveal vision) than that for nondyslexic readers, but do not extend as far as peripheral vision. The findings extend previous research by elucidating the different visual spans within which crowding operates for dyslexic and nondyslexic readers in an online fluency task.     

Increased saccadic rate during smooth pursuit eye movements in patients at Ultra High Risk for developing a psychosis

Abnormalities in eye tracking are consistently observed in schizophrenia patients and their relatives and have been proposed as an endophenotype of the disease. The aim of this study was to investigate the performance of patients at Ultra High Risk (UHR) for developing psychosis on a task of smooth pursuit eye movement (SPEM). Forty-six UHR patients and twenty-eight age and education matched controls were assessed with a task of SPEM and psychiatric questionnaires. Our results showed that both the corrective and non-corrective saccadic rates during pursuit were higher in the UHR group. There were however no differences in smooth pursuit gain between the two groups. The saccadic rate was related to positive UHR symptoms. Our findings indicate that abnormalities in SPEM are already present in UHR patients, prior to a first psychotic episode. These abnormalities occur only in the saccadic system.     

汉语阅读中词N+2的预视对高频词N+1加工影响的眼动研究

本研究采用边界范式,控制单字词N+1的预视加工负荷和词N+2首字的预视信息类型,探讨了汉语阅读中词N+2的预视对高频单字词N+1加工产生的影响。结果发现,当词N+1的预视为低加工负荷时,词N+2首字的预视对词N+1的加工产生了显著的影响;当词N+2首字的预视字与词N+1正字法相似,并且只呈现在副中央凹中时,显著的阻碍了词N+1随后的加工。结果表明,副中央凹中词N+2能够获得预视加工,可能获得正字法预视信息并对随后词N+1的加工产生了影响,并且这种影响受词N+1的预视加工负荷的调节。实验结果符合注意梯度指引模型的假设。     

NEW RELIGIOUS MOVEMENTS AND SCIENCE: RAEL'S PROGRESSIVE PATRONIZING PARASITISM

The article examines the concoction of religion and “science” contained in the revelation that substantiates a new religion: Raelianism, founded and led by the prophet Claude Vorilhon/Rael after having received a revelation in 1974. After a detailed examination both of Rael's prophetic message and his/the Raelians’ interpretative practices, an ad hoc model is presented to describe such concoction (“progressive patronizing parasitism”), and it is compared to other models. It is in particular claimed that Rael, while seemingly talking about “science,” is actually constructing a science‐fictional and even pseudoscientific narrative. The article finally raises the question whether the discussion of the science–religion interaction from the viewpoint of traditional religions can be considered to be immune to the usage of such rhetorical devices.     

When preview information starts to matter: Development of the perceptual span in German beginning readers

How is reading development reflected in eye-movement measures? How does the perceptual span change during the initial years of reading instruction? Does parafoveal processing require competence in basic word-decoding processes? We report data from the first cross-sectional measurement of the perceptual span of German beginning readers (n = 139), collected in the context of the large longitudinal PIER (Potsdamer Intrapersonale Entwicklungsrisiken/Potsdam study of intra-personal developmental risk factors) study of intrapersonal developmental risk factors. Using the moving-window paradigm, eye movements of three groups of students (Grades 1–3) were measured with gaze-contingent presentation of a variable amount of text around fixation. Reading rate increased from Grades 1–3, with smaller increases for higher grades. Perceptual-span results showed the expected main effects of grade and window size: fixation durations and refixation probability decreased with grade and window size, whereas reading rate and saccade length increased. Critically, for reading rate, first-fixation duration, saccade length and refixation probability, there were significant interactions of grade and window size that were mainly based on the contrast between Grades 3 and 2 rather than Grades 2 and 1. Taken together, development of the perceptual span only really takes off between Grades 2 and 3, suggesting that efficient parafoveal processing presupposes that basic processes of reading have been mastered.     

Oculomotor responses of stereo‐anomalous observers to pulse and ramp disparities

We examined oculomotor responses to binocular disparities of one stereo‐normal and three stereo‐anomalous observers, who were identified through a stereoscopic depth‐discrimination task, in two experimental conditions. In the pulse disparity condition, crossed and uncrossed disparities (1–6°) were briefly presented (for .25–2.0 s). In the ramp disparity condition, disparities were varied continuously with constant velocities (.7–2.0°/s) and with an amplitude of 10°. The stereo‐normal observer showed vergence responses to both pulse and ramp disparities. The three stereo‐anomalous observers showed a marked reduction or absence of vergence responses to pulse disparities but showed vergence responses to ramp disparities. The results suggest the existence of separate sub‐systems mediating disparity vergence eye movements.