468 research outputs found

    A New Challenge: Testing the Video Course

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    This paper offers some preliminary thoughts on the testing ofvideo courses, including a review of the literature and an examinationof the research on the subject. The unique characteristics ofvideo courses suggest that different language learning outcomes maybe expected, which means that creating appropriate tests is thereforea new challenge for language teachers. The paper lists subtesttypes, and gives an example of a test used by the authors. Based onthis experience, a number of guidelines are offered regarding thecreation of appropriate tests, and a direction for future research inthe area is suggested

    The Influence of Complex Distractors in the Remote Distractor Paradigm

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    Three experiments examined the influence of complex dis-tractors on the Remote Distractor Effect (RDE), a robust finding of an increase is saccade latencies when two, rather than one possible targets are presented simultaneously (Walker, Deubel, Schneider & Findlay, 1997). In Experiment 1 saccade onset latencies (SOL’s) were greater for central versus peripheral presentation for lexical distractors, but not for non-lexical distractors. Experiment 2 showed that repeated presentation of a distractor results in reduced SOL’s at central presentation, regardless of lexical status. In Experiment 3 differences in saccade onsets were obtained between two types of lexical distractor when presented at parafoveal locations. Detailed analysis revealed that although SOL's are modulated by distractor complexity, RDE magnitudes are not

    Eye movement sequences during simple versus complex information processing of scenes in autism spectrum disorder

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    Minshew and Goldstein (1998) postulated that autism spectrum disorder (ASD) is a disorder of complex information processing. The current study was designed to investigate this hypothesis. Participants with and without ASD completed two scene perception tasks: a simple “spot the difference” task, where they had to say which one of a pair of pictures had a detail missing, and a complex “which one's weird” task, where they had to decide which one of a pair of pictures looks “weird”. Participants with ASD did not differ from TD participants in their ability to accurately identify the target picture in both tasks. However, analysis of the eye movement sequences showed that participants with ASD viewed scenes differently from normal controls exclusively for the complex task. This difference in eye movement patterns, and the method used to examine different patterns, adds to the knowledge base regarding eye movements and ASD. Our results are in accordance with Minshew and Goldstein's theory that complex, but not simple, information processing is impaired in ASD.<br/

    Investigating eye movement acquisition and analysis technologies as a causal factor in differential prevalence of crossed and uncrossed fixation disparity during reading and dot scanning

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    Previous studies examining binocular coordination during reading have reported conflicting results in terms of the nature of disparity (e.g. Kliegl, Nuthmann, &amp; Engbert (Journal of Experimental Psychology General 135:12-35, 2006); Liversedge, White, Findlay, &amp; Rayner (Vision Research 46:2363-2374, 2006). One potential cause of this inconsistency is differences in acquisition devices and associated analysis technologies. We tested this by directly comparing binocular eye movement recordings made using SR Research EyeLink 1000 and the Fourward Technologies Inc. DPI binocular eye-tracking systems. Participants read sentences or scanned horizontal rows of dot strings; for each participant, half the data were recorded with the EyeLink, and the other half with the DPIs. The viewing conditions in both testing laboratories were set to be very similar. Monocular calibrations were used. The majority of fixations recorded using either system were aligned, although data from the EyeLink system showed greater disparity magnitudes. Critically, for unaligned fixations, the data from both systems showed a majority of uncrossed fixations. These results suggest that variability in previous reports of binocular fixation alignment is attributable to the specific viewing conditions associated with a particular experiment (variables such as luminance and viewing distance), rather than acquisition and analysis software and hardware.<br/

    Processing of co-reference in autism spectrum disorder

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    Accuracy for reading comprehension and inferencing tasks has previously been reported as reduced for individuals with autism spectrum disorder (ASD), relative to typically developing (TD) controls. In this study, we used an eye movements and reading paradigm to examine whether this difference in performance accuracy is underpinned by differences in the inferential work required to compute a co-referential link. Participants read two sentences that contained a category noun (e.g., bird) that was preceded by and co-referred to an exemplar that was either typical (e.g., pigeon) or atypical (e.g., penguin). Both TD and ASD participants showed an effect of typicality for gaze durations upon the category noun, with longer times being observed when the exemplar was atypical, in comparison to typical. No group differences or interactions were detected for target processing, and verbal language proficiency was found to predict general reading and inferential skill. The only difference between groups was that individuals with ASD engaged in more re-reading than TD participants. These data suggest that readers with ASD do not differ in the efficiency with which they compute anaphoric links on-line during reading

    Would adults with autism be less likely to bury the survivors? An eye movement study of anomalous text reading

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    In a single eye movement experiment we investigated the effects of context on the time course of local and global anomaly processing during reading in adults with Autism Spectrum Disorder (ASD). In one condition short paragraph texts contained anomalous target words. Detection of the anomaly was only possible through evaluation of word meaning in relation to the global context of the whole paragraph (Passage Level Anomalies). In another condition the anomaly could be detected via computation of a local thematic violation within a single sentence embedded in the paragraph (Sentence Level Anomalies).For the sentence level anomalies the ASD group, in contrast with the typically developing (TD) group, showed early detection of the anomaly as indexed by regressive eye movements from the critical target word upon fixation. Conversely, for the passage level anomalies, and in contrast with the ASD group, the TD group showed early detection of the anomaly, with increased regressive eye movements once the critical word had been fixated.The reversal of the pattern of regression path data for the two groups, for the sentence and passage level anomalies, is discussed in relation to cognitive accounts of ASD

    Saccadic distractor effects: the remote distractor effect (RDE) and saccadic inhibition (SI): A response to McIntosh and Buonocore (2014)

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    We (Walker & Benson, 2013) reported studies in which the spatial effects of distractors on the remote distractor effect (RDE) and saccadic inhibition (SI) were examined. Distractors remote from the target increased mean latency and the skew of the distractor-related distributions, without the presence of dips that are regarded as the hallmark of SI. We further showed that early onset distractors had similar effects although these would not be consistent with existing estimates of the duration of SI (of around 60–70 ms). McIntosh and Buonocore (2014) report a simulation showing that skewed latency distributions can arise from the putative SI mechanism and they also highlighted a number of methodological considerations regarding the RDE and SI as measures of saccadic distractor effects (SDEs). Here we evaluate these claims and note that the measures of SI obtained by subtracting latency distributions (specifically the decrease in saccade frequency—or dip duration) are no more diagnostic of a single inhibitory process, or more sensitive indicators of it, than is median latency. Furthermore the evidence of inhibitory influences of small distractors presented close to the target is incompatible with the explanations of both the RDE and SI. We conclude that saccadic distractor effects may be a more inclusive term to encompass the different characteristics of behavioral effects of underlying saccade target selection

    Cervical cancer and precancerous cervical lesions detected using visual inspection with acetic acid at Livingstone Teaching Hospital

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    Introduction:&nbsp;cervical cancer (CaCx) is the second most common malignancy in women world-wide. Precancer screening aided by visual inspection with acetic acid (VIA) is an early diagnosis method used to detect the lesions that are high indicators of cancer in women. cervical cancer is more prevalent in the developing world affecting mainly women in the reproductive age group and is the commonest cancer among Zambian women. Therefore, the study aimed to determine the prevalence and factors associated with a positive VIA at Livingstone Teaching Hospital (LTH). Methods:&nbsp;this was a cross-sectional study conducted at LTH among 329 women from Livingstone district aged 18 and above, who were coming for routine cervical cancer screening using VIA between 2019 and 2020. Demographic and clinical data were collected from the CaCx clinic. A positive VIA (precancerous cervical lesions) and cervical cancer were the primary and secondary outcome variables. A positive VIA was defined by presence of a dense ulcerative acetowhite area in the transformation zone of the cervix. Cervical cancer diagnosis was defined by presence of cancerous cells on histological examination by a qualified pathologist. Data were analyzed using Statistical package for social sciences (SPSS) version 22.0. Chi-square test, Mann-Whitney and logistic regression were the statistical methods used. Results:&nbsp;the participants had a median (interquartile range) age of 37 (29, 44) years. Prevalence of CaCx and positive VIA were 6% (95% confidence interval (CI) 4, 9) and 19% (95% CI: 15, 24) respectively. At multivariable analysis, the factors associated with a positive VIA were alcohol consumption [odds ratio (OR) 0.30 (95% CI: 0.12, 0.74)] and HIV infection [OR 0.37 (95% CI: 0.19, 0.70)]. Conclusion:&nbsp;the study showed that precancerous cervical lesions are common among our study participants and it was influenced by alcohol consumption and HIV status. There is therefore need to enhance the screening programs using VIA in order to identify cancerous lesions at an early stage for early intervention in resource limited settings

    The influence of emotional face distractors on attentional orienting in Chinese children with autism spectrum disorder

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    The current study examined how emotional faces impact on attentional control at both involuntary and voluntary levels in children with and without autism spectrum disorder (ASD). A non-face single target was either presented in isolation or synchronously with emotional face distractors namely angry, happy and neutral faces. ASD and typically developing children made more erroneous saccades towards emotional distractors relative to neutral distractors in parafoveal and peripheral conditions. Remote distractor effects were observed on saccade latency in both groups regardless of distractor type, whereby time taken to initiate an eye movement to the target was longest in central distractor conditions, followed by parafoveal and peripheral distractor conditions. The remote distractor effect was greater for angry faces compared to happy faces in the ASD group. Proportions of failed disengagement trials from central distractors, for the first saccade, were higher in the angry distractor condition compared with the other two distractor conditions in ASD, and this effect was absent for the typical group. Eye movement results suggest difficulties in disengaging from fixated angry faces in ASD. Atypical disengagement from angry faces at the voluntary level could have consequences for the development of higher-level socio-communicative skills in ASD

    Cat and mouse search: the influence of scene and object analysis on eye movements when targets change locations during search

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    We explored the influence of early scene analysis and visible object characteristics on eye movements when searching for objects in photographs of scenes. On each trial, participants were shown sequentially either a scene preview or a uniform grey screen (250 ms), a visual mask, the name of the target and the scene, now including the target at a likely location. During the participant's first saccade during search, the target location was changed to: (i) a different likely location, (ii) an unlikely but possible location or (iii) a very implausible location. The results showed that the first saccade landed more often on the likely location in which the target re-appeared than on unlikely or implausible locations, and overall the first saccade landed nearer the first target location with a preview than without. Hence, rapid scene analysis influenced initial eye movement planning, but availability of the target rapidly modified that plan. After the target moved, it was found more quickly when it appeared in a likely location than when it appeared in an unlikely or implausible location. The findings show that both scene gist and object properties are extracted rapidly, and are used in conjunction to guide saccadic eye movements during visual search
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