title: Reduced global processing bias in people with a history of mild traumatic brain injury: Grass everywhere and not a field in sight

authors: Sidhu, Amanpreet

abstract: Mild traumatic brain injury (mTBI) is increasingly recognized as a disconnection syndrome, due to the prevalence of disrupted long-range connections. Long-range connections refer to neural pathways that span across brain regions, allowing communication and synchronization between different brain areas. Disruption of these connections is associated with the inability to efficiently integrate local information (i.e., multiple visual attributes) into the percept of a single global shape. The aim of this thesis was to investigate whether people with a history of mTBI exhibit a reduced ability to integrate local information into meaningful context. 
	Chapter 2 investigated whether visual integration was impaired in people with a history of mTBI, using visual illusions. Susceptibility to visual illusions demonstrates effective integration of visual information to provide a global picture, with surrounding elements automatically integrated into the perception of local elements. Results from Chapter 2 revealed that people with a history of mTBI exhibited decreased susceptibility to visual illusions, suggesting diminished automatic integration of visual information in a global manner; rather, these individuals appeared to prioritize analysis of local details within a visual stimulus. To further investigate this assumption, we employed the Navon task in Chapter 3 to assess whether people with a history of mTBI demonstrated a tendency to prioritize the processing of local details over global information when presented with multiple objects. This task was chosen as it provides a reliable measure of the extent to which individuals engage in global or local processing. The results revealed that people with a recent history of mTBI (within 12 months) had a reduced bias towards processing global elements of a figure (i.e., attending to the overall configuration of the object), indicating a reduced automatic tendency to process visual information as a coherent global percept. In contrast, individuals who sustained their most recent mTBI more than one year earlier displayed the same global processing bias as control participants (i.e., they attended to the overall structure of the visual stimulus first). 
Following this observation, it was speculated that people with a history of mTBI may also apply a de-automatized processing style to their movements. It has been argued that individuals with a high propensity to consciously process their movements are more likely to display de-automaticity (inefficient or disrupted movement); therefore, in Chapter 4 we assessed the propensity of people with a history of mTBI to consciously monitor and control their movements, using the Movement Specific Reinvestment Scale (MSRS). The results showed that people with a history of mTBI had a higher propensity for MSRS than controls. In addition, we found that time since most recent mTBI was negatively associated with the conscious motor processing subscale of the MSRS. 
	Chapter 5 builds upon the findings presented in Chapters 2 and 3, delving into the potential implications for real-world behaviours like visual anticipation. Specifically, this chapter investigated the impact of mTBI on individuals' ability to anticipate both deceptive and non-deceptive movements. The results demonstrate that people with a history of mTBI display significantly better anticipation of both deceptive and non-deceptive movements compared to control. Additionally, it was observed that people with a history of mTBI took longer to respond compared to controls.
	The findings of this thesis suggest that there is an increased tendency to deconstruct visual and movement information following mTBI, highlighting a need for further research to better understand the effects of mTBI on information processing and to develop effective diagnostic and treatment strategies.

text: Reduced global processing bias in people with a history of mild traumatic brain injury: Grass everywhere and not a field in sight Mild traumatic brain injury (mTBI) is increasingly recognized as a disconnection syndrome, due to the prevalence of disrupted long-range connections. Long-range connections refer to neural pathways that span across brain regions, allowing communication and synchronization between different brain areas. Disruption of these connections is associated with the inability to efficiently integrate local information (i.e., multiple visual attributes) into the percept of a single global shape. The aim of this thesis was to investigate whether people with a history of mTBI exhibit a reduced ability to integrate local information into meaningful context. 
	Chapter 2 investigated whether visual integration was impaired in people with a history of mTBI, using visual illusions. Susceptibility to visual illusions demonstrates effective integration of visual information to provide a global picture, with surrounding elements automatically integrated into the perception of local elements. Results from Chapter 2 revealed that people with a history of mTBI exhibited decreased susceptibility to visual illusions, suggesting diminished automatic integration of visual information in a global manner; rather, these individuals appeared to prioritize analysis of local details within a visual stimulus. To further investigate this assumption, we employed the Navon task in Chapter 3 to assess whether people with a history of mTBI demonstrated a tendency to prioritize the processing of local details over global information when presented with multiple objects. This task was chosen as it provides a reliable measure of the extent to which individuals engage in global or local processing. The results revealed that people with a recent history of mTBI (within 12 months) had a reduced bias towards processing global elements of a figure (i.e., attending to the overall configuration of the object), indicating a reduced automatic tendency to process visual information as a coherent global percept. In contrast, individuals who sustained their most recent mTBI more than one year earlier displayed the same global processing bias as control participants (i.e., they attended to the overall structure of the visual stimulus first). 
Following this observation, it was speculated that people with a history of mTBI may also apply a de-automatized processing style to their movements. It has been argued that individuals with a high propensity to consciously process their movements are more likely to display de-automaticity (inefficient or disrupted movement); therefore, in Chapter 4 we assessed the propensity of people with a history of mTBI to consciously monitor and control their movements, using the Movement Specific Reinvestment Scale (MSRS). The results showed that people with a history of mTBI had a higher propensity for MSRS than controls. In addition, we found that time since most recent mTBI was negatively associated with the conscious motor processing subscale of the MSRS. 
	Chapter 5 builds upon the findings presented in Chapters 2 and 3, delving into the potential implications for real-world behaviours like visual anticipation. Specifically, this chapter investigated the impact of mTBI on individuals' ability to anticipate both deceptive and non-deceptive movements. The results demonstrate that people with a history of mTBI display significantly better anticipation of both deceptive and non-deceptive movements compared to control. Additionally, it was observed that people with a history of mTBI took longer to respond compared to controls.
	The findings of this thesis suggest that there is an increased tendency to deconstruct visual and movement information following mTBI, highlighting a need for further research to better understand the effects of mTBI on information processing and to develop effective diagnostic and treatment strategies.

year: 2024

title: Fully supervised training of Gaussian radial basis function networks in WEKA

authors: Frank, Eibe

subjects: Machine learning

abstract: Radial basis function networks are a type of feedforward network with a long history in machine learning. In spite of this, there is relatively little literature on how to train them so that accurate predictions are obtained. A common strategy is to train the hidden layer of the network using k-means clustering and the output layer using supervised learning. However, Wettschereck and Dietterich found that supervised training of hidden layer parameters can improve predictive performance. They investigated learning center locations, local variances of the basis functions, and attribute weights, in a supervised manner.

This document discusses supervised training of Gaussian radial basis function networks in the WEKA machine learning software. More specifically, we discuss the RBFClassifier and RBFRegressor classes available as part of the RBFNetwork package for WEKA 3.7 and consider (a) learning of center locations and one global variance parameter, (b) learning of center locations and one local variance parameter per basis function, and (c) learning center locations with per-attribute local variance parameters. We also consider learning attribute weights jointly with other parameters.

text: Fully supervised training of Gaussian radial basis function networks in WEKA Radial basis function networks are a type of feedforward network with a long history in machine learning. In spite of this, there is relatively little literature on how to train them so that accurate predictions are obtained. A common strategy is to train the hidden layer of the network using k-means clustering and the output layer using supervised learning. However, Wettschereck and Dietterich found that supervised training of hidden layer parameters can improve predictive performance. They investigated learning center locations, local variances of the basis functions, and attribute weights, in a supervised manner.

This document discusses supervised training of Gaussian radial basis function networks in the WEKA machine learning software. More specifically, we discuss the RBFClassifier and RBFRegressor classes available as part of the RBFNetwork package for WEKA 3.7 and consider (a) learning of center locations and one global variance parameter, (b) learning of center locations and one local variance parameter per basis function, and (c) learning center locations with per-attribute local variance parameters. We also consider learning attribute weights jointly with other parameters.

year: 2014

title: Whakarongo mai!: Transformative teaching to support Māori identity and success in a mainstream school

authors: Gilgen, Renée

subjects: Māori and mainstream education

abstract: This thesis topic emerged following a year’s teaching experience in a mainstream classroom during 2009. My cultural assumptions of being a Māori teacher in a mainstream class were challenged predominantly by a group of Māori students in the classroom. The level of despondency I felt as a result of disruptive student behaviours forced me to reassess my own socio-cultural constructs which had influenced the formation of my identity as Māori and as a mainstream teacher. The purpose of this study was to understand and explore a transformational behavioural shift which occurred within a group of Māori students during 2009 and the level of support they felt they received as Māori within a mainstream classroom context. National and international literature demonstrates that transformative praxis is both reflective and active. Successful inclusive teaching requires a personal and professional commitment to firstly understand individual cultural constructs to then better understand how learners are perceived and positioned. Culturally responsive pedagogy ensures that all students’ cultural practices and values are acknowledged and included into classroom teaching and learning programmes. In a New Zealand mainstream context, the Treaty of Waitangi principles of ‘partnership’, ‘participation’ and ‘protection’ serve as a bi-cultural ‘power-sharing’ metaphor from which all mainstream teachers of Māori students can successfully encourage student voice and foster reciprocal teaching and learning relationships. My use of qualitative research methods and kaupapa Māori principles to guide the research process ensured that Māori cultural protocols and practices were honoured. My role as a Māori insider researcher meant that my relationship with the participants was already established. Our reflections as Māori students and a Māori teacher in a mainstream classroom context were based from shared teaching and learning experiences during 2009. Researcher reflexivity has ensured that the research integrity, validity and reliability have remained high. The research findings present the reflections of both the participants and researcher as Māori students and as a Māori teacher during 2009. Participants believed that teaching and learning programmes which incorporated te reo Māori served to honour their identity as Māori. However, their awareness of participating with tikanga Māori principles of whānaungatanga (relationships), manaakitanga (caring), ako (reciprocity) and aroha (respect) embedded within classroom activities that were exclusively in English, were not identified as being relevant to them as Māori. Similarly, the Treaty of Waitangi principles lacked transparency within my teaching pedagogy. Two key implications for teaching and learning in mainstream schools and classrooms were identified. Firstly, there is an urgency for mainstream school managers, leaders and teachers to develop an understanding of the Treaty of Waitangi and its significance for the 21st Century mainstream teacher and learner. A bi-cultural understanding of ourselves as treaty partners support Māori cultural values and practices within increasingly diverse mainstream school and classroom contexts. Māori students‟ success becomes the responsibility of all mainstream managers, leaders and teachers as treaty partners. Secondly, inclusive and culturally responsive pedagogy demonstrates that Māori and non-Māori mainstream teachers are capable of effectively engaging Māori students with learning while acknowledging and reaffirming their cultural identity and language as tangata whenua. Overall, my commitment for Māori students to be supported as Māori within mainstream school and classroom context has been enriched and strengthened as a result of this research study. The cultural and professional tensions I have experienced in mainstream contexts have challenged the socio-cultural constructs that I had accepted as being my cultural ‘norm.’

text: Whakarongo mai!: Transformative teaching to support Māori identity and success in a mainstream school This thesis topic emerged following a year’s teaching experience in a mainstream classroom during 2009. My cultural assumptions of being a Māori teacher in a mainstream class were challenged predominantly by a group of Māori students in the classroom. The level of despondency I felt as a result of disruptive student behaviours forced me to reassess my own socio-cultural constructs which had influenced the formation of my identity as Māori and as a mainstream teacher. The purpose of this study was to understand and explore a transformational behavioural shift which occurred within a group of Māori students during 2009 and the level of support they felt they received as Māori within a mainstream classroom context. National and international literature demonstrates that transformative praxis is both reflective and active. Successful inclusive teaching requires a personal and professional commitment to firstly understand individual cultural constructs to then better understand how learners are perceived and positioned. Culturally responsive pedagogy ensures that all students’ cultural practices and values are acknowledged and included into classroom teaching and learning programmes. In a New Zealand mainstream context, the Treaty of Waitangi principles of ‘partnership’, ‘participation’ and ‘protection’ serve as a bi-cultural ‘power-sharing’ metaphor from which all mainstream teachers of Māori students can successfully encourage student voice and foster reciprocal teaching and learning relationships. My use of qualitative research methods and kaupapa Māori principles to guide the research process ensured that Māori cultural protocols and practices were honoured. My role as a Māori insider researcher meant that my relationship with the participants was already established. Our reflections as Māori students and a Māori teacher in a mainstream classroom context were based from shared teaching and learning experiences during 2009. Researcher reflexivity has ensured that the research integrity, validity and reliability have remained high. The research findings present the reflections of both the participants and researcher as Māori students and as a Māori teacher during 2009. Participants believed that teaching and learning programmes which incorporated te reo Māori served to honour their identity as Māori. However, their awareness of participating with tikanga Māori principles of whānaungatanga (relationships), manaakitanga (caring), ako (reciprocity) and aroha (respect) embedded within classroom activities that were exclusively in English, were not identified as being relevant to them as Māori. Similarly, the Treaty of Waitangi principles lacked transparency within my teaching pedagogy. Two key implications for teaching and learning in mainstream schools and classrooms were identified. Firstly, there is an urgency for mainstream school managers, leaders and teachers to develop an understanding of the Treaty of Waitangi and its significance for the 21st Century mainstream teacher and learner. A bi-cultural understanding of ourselves as treaty partners support Māori cultural values and practices within increasingly diverse mainstream school and classroom contexts. Māori students‟ success becomes the responsibility of all mainstream managers, leaders and teachers as treaty partners. Secondly, inclusive and culturally responsive pedagogy demonstrates that Māori and non-Māori mainstream teachers are capable of effectively engaging Māori students with learning while acknowledging and reaffirming their cultural identity and language as tangata whenua. Overall, my commitment for Māori students to be supported as Māori within mainstream school and classroom context has been enriched and strengthened as a result of this research study. The cultural and professional tensions I have experienced in mainstream contexts have challenged the socio-cultural constructs that I had accepted as being my cultural ‘norm.’

year: 2010