Global ETD Search

1	Hemispheric effects in binocular visual word recognition : experiments and cognitive modelling Obregón, Mateo January 2013 (has links) Functionally, a vertically split fovea should confer an advantage to the processor. Visual stumuli arriving to each eye would be vertically split and the two parts sent to different hemispheres, obeying the crossed nature of the visual pathways. I test the prediction of a functional advantage for the separate lateralisation of text processing from the two eyes. I explore this hypothesis by means of psycholinguistic experimentation and cognitive modelling. I employed a haploscope to show foveated text to the two eyes separately, controlling for location and presentation duration, and guaranteeing that each eye could not see the other eye's stimuli. I carried out a series of experiments, based on this novel paradigm, to explore the effects of a vertically split fovea on correctness of word perception. The experiments showed: (i) words presented exclusively to the contralateral hemifoveas are more correctly reported than words presented exclusively to the ipsilateral hemifoveas; (ii) the same full word shown to both eyes and available for fusion led to better perception; (iii) word endings with fewer type-count neighbours were more accurately reported, as were beginnings with larger type-count neighbours; (iv) uncrossed-eye stumuli were better perceived than crossed-eye stimuli; (v) principled roles in a model of isolated word recognition for lexical and sublexical neighbourhood statistics, syllabicity, hemispheric fine- and coarse-coding differences, sex of the reader, handedness, left and right eye, and visual pathways. Finally, I propose a connectionist model of visual word recognition that incorporates these findings and is a basis for further exploration. 612.8
2	Investigating the Portuguese-English Bilingual Mental Lexicon: Crosslinguistic Orthographic and Phonological Overlap in Cognates and False Friends Alves-Soares, Leonardo 01 October 2020 (has links) This dissertation investigates how cognates are organized in the bilingual mental lexicon and examines whether orthography in one language, via phonological representations, influences the processing of cognates and false friends in the other language. In light of the framework of two well-known models of bilingual visual word recognition, the Bilingual Interactive Activation (BIA) and the Bilingual Interactive Activation Plus (BIA+), the premise is that there is activation from orthography to phonology across a bilingual’s two languages and that this activation is modulated by the degree of orthographic and phonological code overlap. Two objective metrics were used to assess crosslinguistic similarity of Portuguese-English cognates and false friends that were selected for a cross-language lexical decision task with masked priming. Dynamic time warping (DTW), an algorithm that was originally conceived to compare different speech patterns in automatic speech recognition and to measure acoustic similarity between two time-dependent sequences, was used to compute crosslinguistic phonological similarity. The Normalized Levenshtein Distance (NLD), an algorithm that calculates the minimum number of single-character insertions, deletions or substitutions required to change one word into another and normalizes the result by their lengths, was used to compute crosslinguistic orthographic similarity. Portuguese-English bilinguals who acquired their second language after reaching puberty, and English functional monolinguals who grew up speaking primarily English were recruited to participate in the experimental task. Based on collected reaction time and accuracy data, mixed-effects models analyses are used to estimate the individual effects of crosslinguistic orthographic, phonological and semantic similarity and the role each of them, along with English proficiency, word frequency and length play in the organization of the Portuguese-English bilingual mental lexicon. bilingual mental lexicon Portuguese English Portuguese-English bilinguals English functional monolinguals cognates false friends crosslinguistic overlap crosslinguistic similarity semantic lexical decision task LDT masked priming spreading activation RHM BIA BIA+ Multilink orthographic representations phonological representations dynamic time warping DTW Normalized Levenshtein Distance NLD mixed-effects models lmer glmer reaction time accuracy

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Hemispheric effects in binocular visual word recognition : experiments and cognitive modelling

Investigating the Portuguese-English Bilingual Mental Lexicon: Crosslinguistic Orthographic and Phonological Overlap in Cognates and False Friends