508 research outputs found
Word skipping: implications for theories of eye movement control in reading
This chapter provides a meta-analysis of the factors that govern word skipping in reading. It is concluded that the primary predictor is the length of the word to be skipped. A much smaller effect is due to the processing ease of the word (e.g., the frequency of the word and its predictability in the sentence)
The right visual field advantage and the optimal viewing position effect: On the relation between foveal and parafoveal word recognition
Recent developments on the optimal viewing position (OVP) effect suggest that it may be caused
by the same factors that underlie the right visual field advantage in word recognition. This raises
the question of the relationship between foveal and parafoveal word recognition. Three
experiments are reported in which participants identified tachistoscopically presented words that
were presented randomly in foveal and parafoveal vision. The results show that both the OVP
effect and the right visual field advantage for word recognition are part of a larger extended OVP
curve that has the shape of a Gaussian distribution with the mode shifted to the left of the center of
the stimulus word. The shift of the distribution is a function of word length, but not of presentation
duration; it is also slightly moderated by the information value of word beginning and word end
The influence of semantic context on initial eye landing sites in words
To determine the role of ongoing processing on eye guidance in reading, two studies examined the effects of semantic context on the eyes' initial landing position in words of different levels of processing diffculty. Results from both studies clearly indicate a shift of the initial fixation location towards the end of the words for words that can be predicted from a prior semantic context. However, shifts occur only in high-frequency words and with prior fixations
close to the beginning of the target word. These results suggest that ongoing perceptual and linguistic processes can affect the decision of where to send the eyes next in reading. They are explained in terms of the easiness of processing associated with the target words when located
in parafoveal vision. It is concluded that two critical factors might help observing effects of linguistic variables on initial landing sites, namely, the frequency of the target word and the position where the eyes are launched from as regards to the beginning of the target word. Results also provide evidence for an early locus of semantic context effects in reading
About the global effect and the critical role of retinal eccentricity: Implications for eye movements in reading
In the present paper, I review evidence for the universality of the global effect, i.e. the general tendency to move the eyes towards the centre of gravity of the peripheral configu-ration, and show that the effect is strongly constrained by the retinal location of the stimuli. First, stimuli that are displayed in a central foveal region of a 1-1.5° radius fail to deviate the eyes in a centre-of-gravity manner; this is referred to as the foveal dead zone. Second, the stimuli that are too eccentric relative to the saccade target and/or the main stimulation site are filtered out. These limitations reflect physiological constraints and the dynamics of the patterns of activity in a visual saliency map. They form the basis for a low-level centre-of-gravity type account of eye guidance in natural perceptual tasks such as reading
Mislocated fixations during reading and the inverted optimal viewing position effect
AbstractRefixation probability during reading is lowest near the word center, suggestive of an optimal viewing position (OVP). Counterintuitively, fixation durations are largest at the OVP, a result called the inverted optimal viewing position (IOVP) effect [Vitu, McConkie, Kerr, & O’Regan, (2001). Vision Research 41, 3513–3533]. Current models of eye-movement control in reading fail to reproduce the IOVP effect. We propose a simple mechanism for generating this effect based on error-correction of mislocated fixations due to saccadic errors. First, we propose an algorithm for estimating proportions of mislocated fixations from experimental data yielding a higher probability for mislocated fixations near word boundaries. Second, we assume that mislocated fixations trigger an immediate start of a new saccade program causing a decrease of associated durations. Thus, the IOVP effect could emerge as a result of a coupling between cognitive and oculomotor processes
The IOVP effect in mindless reading: Experiment and modeling
AbstractFixation durations in reading are longer for within-word fixation positions close to word center than for positions near word boundaries. This counterintuitive result was termed the Inverted-Optimal Viewing Position (IOVP) effect. We proposed an explanation of the effect based on error-correction of mislocated fixations [Nuthmann, A., Engbert, R., & Kliegl, R. (2005). Mislocated fixations during reading and the inverted optimal viewing position effect. Vision Research, 45, 2201–2217], that suggests that the IOVP effect is not related to word processing. Here we demonstrate the existence of an IOVP effect in “mindless reading”, a z-string scanning task. We compare the results from experimental data with results obtained from computer simulations of a simple model of the IOVP effect and discuss alternative accounts. We conclude that oculomotor errors, which often induce mislocalized fixations, represent the most important source of the IOVP effect
Pediatric Liver Transplantation: Then and Now
This paper reviews the past 50 years of liver transplantation in children from the perspective of patient demographics, perioperative patient management, surgical techniques, immunosuppression and patient outcomes
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