Inflectional morphology in the literacy of deaf children

Severe literacy impairments are well documented in the deaf population. Morphology provides a source of text-to-meaning associations that should be available to the deaf. In this thesis, different levels of morphological awareness necessary for literacy were tested. Deaf children demonstrated that they associated morphologically related words – the first level of awareness. This was evidenced in a short-term memory task in which words sharing morphological overlap were confused more often than words sharing orthographic or semantic overlap (although these associations may have involved the combined effects of orthographic and semantic overlap). Deaf children also demonstrated knowledge of morphological generalisation (the second level of awareness) by producing predicted plural nonword spellings and over-regularisations. Finally, they demonstrated morpho-syntactic awareness – in a self-paced reading task they revealed sensitivity to subject-verb number agreement. However, deaf children demonstrated limited knowledge of irregular plural nouns and of morpho-syntax. In the self-paced reading task, they were slow to perform syntactic integration and they failed to make explicit use of agreement in a judgement task. Furthermore, even reading-age appropriate morphological awareness represents a substantial chronological delay. The findings therefore suggest that deaf children could benefit from explicit education in morphographic rules and exceptions as well as training in morpho-synta

Maskless photolithography using UV LEDs

A UV light emitting diode (LED) with a maximum output of 372 nm was collimated using a pinhole and a small plastic tube and focused using a microscope objective onto a substrate for direct lithographic patterning of the photoresist. Movement of the substrate with a motorised linear stage (syringe pump) allowed lines in SU-8 to be pattered with a width down to 35 {micro}m at a linear velocity of 80 {micro}m s-1, while in the dry film resist Ordyl SY 330, features as narrow as 17 {micro}m were made at a linear velocity of 245 {micro}m s-1. At this linear velocity, a 75 mm long feature could be patterned in 5 min. Functional microfluidic devices were made by casting PDMS on a master made by LED lithography. The results show that UV LEDs are a suitable light source for direct writing lithography, offering a budget friendly, and high resolution alternative for rapid prototyping of features smaller than 20 {micro}m

Sublexical and syntactic processing during reading:evidence from eye movements of typically developing and dyslexic readers.

Skilled, typically developing readers and children with dyslexia read correct sentences and sentences that contained verb errors that were pseudo-homophones, morphological over-regularisations or syntactic errors. All errors increased looking time but the nature of the error and participant group influenced the time course of the effects. The pseudo-homophone effect was significant in all eye-movement measures for adults (N = 26), intermediate (N = 37) and novice typically developing readers (N = 38). This effect was larger for intermediate readers than other groups in total duration. In contrast, morphological over-regularisations increased gaze and total duration (but not first fixation) for intermediate and novice readers, and only total duration for adult readers. Syntactic errors only increased total duration. Children with dyslexia (N = 19) demonstrated smaller effects of pseudo-homophones and over-regularisations than controls, but their processing of syntactic errors was similar. We conclude that dyslexic children's difficulties with reading are linked to overreliance on phonological decoding and underspecified morphological processing, which impacts on word level reading. We highlight that the findings fit well within the grain-size model of word readin

Variability in auditory processing performance is associated with reading difficulties rather than with history of otitis media

The nature and cause of auditory processing deficits in dyslexic individuals have been debated for decades. Auditory processing deficits were argued to be the first step in a causal chain of difficulties, leading to difficulties in speech perception and thereby phonological processing and literacy difficulties. More recently, it has been argued that auditory processing difficulties may not be causally related to language and literacy difficulties. This study compares two groups who have phonological processing impairments for different reasons: dyslexia and a history of otitis media (OM). We compared their discrimination thresholds and response variability to chronological age- and reading age-matched controls, across three auditory processing tasks: frequency discrimination, rise-time discrimination and speech perception. Dyslexic children showed raised frequency discrimination thresholds in comparison with age-matched controls but did not differ from reading age-matched controls or individuals with a history of OM. There were no group differences on speech perception or rise-time tasks. For the dyslexic children, there was an association between phonological awareness and frequency discrimination response variability, but no association with thresholds. These findings are not consistent with a ‘causal chain’ explanation but could be accounted for within a multiple deficits view of literacy difficulties