Perceptual Learning – Perceptual Changes in Learning New Categories : An extended abstract (autoreferat) submitted in partial fulfillment of the requirements for the degree of Ph.D. in Psychology

Perceptual learning traditionally focuses on studying early plasticity in the sensory pathways. Categorization is a task typically attributed to relatively higher-level cognition. This dissertation explores whether visual categorization of simple objects involves perceptual learning. A simple, physiologically plausible neural network model is put forward to demonstrate how both supervised and unsupervised learning could take place in visual categorization. The model shows how early perceptual representations could be formed, adjusted and reorganized without feedback. At the same time, the re-weighting of the connections between low-level representations and mid-level perceptual structures allows the selective filtering of early-level information and the formation through supervised learning of perceptual detectors for characteristic parts of objects. The model demonstrates how perceptual learning processes could take place in seemingly higher-level tasks like categorical learning of simple objects. Several experiments, using a position transfer paradigm in categorical learning of simple objects, are presented in addition to the new model. They confirm empirically the claims of the model: that visual categorical learning involves lower-level perceptual learning processes. Evidence for such processes is found in the incomplete transfer of learning when the stimuli are presented at a new location in the visual field. This effect is observed even when the participants’ categorization strategy is very simple and explicit. These results complement a large pool of similar findings for arguably lower-level perceptual tasks like vernier discrimination or orientation judgment. This dissertation argues that visual categorical learning of simple objects involves low-level perceptual learning processes, similar to the processes in typical sensory perceptual tasks

Regional and Ethnic Disparities of School-to-Work Transitions in Bulgaria

Bulgaria’s educational and economic landscapes are marked by substantial regional disparities that are interlaced with ethnic inequalities in school-to-work transitions. Young adults from Roma and Turkish origins particularly suffer from disadvantages with respect to education and labour market participation. We ask how ethnicity affects labour market entry in Bulgaria once educational resources of different ethnic groups are accounted for, and how regional contexts impact ethnic disparities in employment insecurities. Building on comparative school-to-work transition (STWT) concepts and on the labour queueing approach, we assume that ethnic disparities in the STWTs of youths in Bulgaria depend on the degree of urbanisation and the strength and structure of the regional economy. The study draws on data from the Bulgarian School Leaver Survey 2014 of 2103 young adults who had left education in the five years preceding the survey. Descriptive analysis and multilevel logistic regression models were applied to analyse STWT patterns with a special focus on education, regional contexts, and ethnicity. The results highlight that STWT risks differ considerably across the Bulgarian regions. The strength of the local economy thereby moderates ethnic disparities. Young people from Roma and Turkish origins are much less disadvantaged to transition towards employment compared to ethnic Bulgarians the stronger the local economy gets. Our study has several policy implications. In addition to the development of public and private employment opportunities for disadvantaged young people, special attention should also be paid to the development of quality vocational education at the national and regional leve

ICAR: endoscopic skull‐base surgery

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Regional and Ethnic Disparities of School-to-Work Transitions in Bulgaria

Bulgaria’s educational and economic landscapes are marked by substantial regional disparities that are interlaced with ethnic inequalities in school-to-work transitions. Young adults from Roma and Turkish origins particularly suffer from disadvantages with respect to education and labour market participation. We ask how ethnicity affects labour market entry in Bulgaria once educational resources of different ethnic groups are accounted for, and how regional contexts impact ethnic disparities in employment insecurities. Building on comparative school-to-work transition (STWT) concepts and on the labour queueing approach, we assume that ethnic disparities in the STWTs of youths in Bulgaria depend on the degree of urbanisation and the strength and structure of the regional economy. The study draws on data from the Bulgarian School Leaver Survey 2014 of 2103 young adults who had left education in the five years preceding the survey. Descriptive analysis and multilevel logistic regression models were applied to analyse STWT patterns with a special focus on education, regional contexts, and ethnicity. The results highlight that STWT risks differ considerably across the Bulgarian regions. The strength of the local economy thereby moderates ethnic disparities. Young people from Roma and Turkish origins are much less disadvantaged to transition towards employment compared to ethnic Bulgarians the stronger the local economy gets. Our study has several policy implications. In addition to the development of public and private employment opportunities for disadvantaged young people, special attention should also be paid to the development of quality vocational education at the national and regional level