Exploring orthographic neighborhood size effects in a computational model of Chinese character naming

Orthographic neighborhood (N) size effects have been extensively studied in English consistently producing a facilitatory effect in word naming tasks. In contrast, several recent studies on Chinese character naming have demonstrated an inhibitory effect of neighborhood size. Response latencies tend to be inhibited by inconsistent characters with large neighborhoods relative to small neighborhoods. These differences in neighborhood effects between languages may depend on the characteristics (depth) of the mapping between orthography and phonology. To explore this, we first conducted a behavioral experiment to investigate the relationship between neighborhood size, consistency and reading response. The results showed an inhibitory effect of neighborhood size for inconsistent characters but a facilitatory effect for consistent characters. We then developed two computational models based on parallel distributed processing principles to try and capture the nature of the processing that leads to these results in Chinese character naming. Simulations using models based on the triangle model of reading indicated that consistency and neighborhood size interact with the division of labor between semantics and phonology to produce these effects

Different processes for reading words learned before and after onset of literacy

Learning to read has a substantial effect on the representations of spoken and meaning forms of words. In this paper we assess literacy effects beyond representational changes, focusing on adaptations to the architecture of the reading system that maps between these representations. We present a connectionist model of reading that predicted distinct processing of pre- and post-literacy acquired words. For reading for meaning, words learned prior to literacy were processed more indirectly via phonological representations, whereas for post-literacy acquired words, processing was more direct along the orthography to semantics pathway. This more computationally intensive route was prioritised because indirect phonology to semantics mappings were unavailable. Such an effect was less apparent for naming, because learning direct orthography to phonology mappings is less computationally intensive. These results were confirmed in an analysis of naming and lexical decision behavioural data. The effect of literacy onset remains an observable artefact in adult reading

Global versus phonemic similarity : evidence in support of multi-level representation

There is long-standing debate about the extent to which children cognitively represent words in terms of global properties or phonological segments, yet few studies have investigated how children’s sensitivity to phonemic versus global similarity changes over time. The current study uses a mispronunciation-reconstruction task to measure both types of sensitivity within a cross-sectional (N=90, aged 3;2 to 5;7) and longitudinal sample (N=23, aged 3;2 to 5;1). The results show that children’s sensitivity to phonemes increases over the first two years of school but does not reach adult levels. The findings indicate that global similarity relations remain important throughout development and support the idea of multi-level representation

Lexical restructuring in preliterate children: Evidence from novel measures of phonological representation

There is substantial debate in the literature surrounding the development of children's phonological representations (PRs). Although infant studies have shown children's representations to contain fine phonetic detail, a consensus is yet to be reached about how and when phonemic categories emerge. This study used novel implicit PR measures with preschool children (n = 38, aged 3 years, 6 months to 4 years, 6 months) to test predictions made by these competing accounts of PR development. The measures were designed to probe PR segmentation at the phoneme (rather than the phone) level without requiring an explicit awareness of phonemes. The results provide evidence in support of vocabulary driven restructuring, with PR segmentation found to be related to vocabulary when controlling for age

Mismatch Negativity (MMN) reveals inefficient auditory ventral stream function in chronic auditory comprehension impairments

Background: Auditory discrimination is significantly impaired in Wernicke’s aphasia (WA) and thought to be causatively related to the language comprehension impairment which characterises the condition. This study used mismatch negativity (MMN) to investigate the neural responses corresponding to successful and impaired auditory discrimination in WA. Methods: Behavioural auditory discrimination thresholds of CVC syllables and pure tones were measured in WA (n=7) and control (n=7) participants. Threshold results were used to develop multiple-deviant mismatch negativity (MMN) oddball paradigms containing deviants which were either perceptibly or non-perceptibly different from the standard stimuli. MMN analysis investigated differences associated with group, condition and perceptibility as well as the relationship between MMN responses and comprehension (within which behavioural auditory discrimination profiles were examined). Results: MMN waveforms were observable to both perceptible and non-perceptible auditory changes. Perceptibility was only distinguished by MMN amplitude in the PT condition. The WA group could be distinguished from controls by an increase in MMN response latency to CVC stimuli change. Correlation analyses displayed relationship between behavioural CVC discrimination and MMN amplitude in the control group, where greater amplitude corresponded to better discrimination. The WA group displayed the inverse effect; both discrimination accuracy and auditory comprehension scores were reduced with increased MMN amplitude. In the WA group, a further correlation was observed between the lateralisation of MMN response and CVC discrimination accuracy; the greater the bilateral involvement the better the discrimination accuracy. Conclusions: The results from this study provide further evidence for the nature of auditory comprehension impairment in WA and indicate that the auditory discrimination deficit is grounded in a reduced ability to engage in efficient hierarchical processing and the construction of invariant auditory objects. Correlation results suggest that people with chronic WA may rely on an inefficient, noisy right hemisphere auditory stream when attempting to process speech stimuli

Introduction

This introduction sets the scene for the special issue through an overview of extant anthropological approaches to witnessing and a discussion of the collection’s three main themes: truths, technologies and transformations. It lays the groundwork for a distinctly anthropological approach to witnessing in three ways. First, by drawing together disparate ethnographic takes on witnessing, it expands the anthropological analysis of witnessing beyond its conventional foci (e.g. legal or media settings). Second, it makes a case for attending not only to witnessing’s semantics and subjectivities but also to its structural, relational, performative and material dimensions. Finally, it puts ethnographic analyses of witnessing in dialogue with reflexive discussions of anthropological witnessing, asking what each can bring to the other. In a ‘post-truth’ moment, when our interlocutors are producing their own testimonies and representations, it is vital to rethink what it means for anthropologists to (bear) witness – and who/what we do it for.Brunel University London; European Research Counci