Unitization during Category Learning

Five experiments explored the question of whether new perceptual units can be developed if they are diagnostic for a category learning task, and if so, what are the constraints on this unitization process? During category learning, participants were required to attend either a single component or a conjunction of five components in order to correctly categorize an object. In Experiments 1-4, some evidence for unitization was found in that the conjunctive task becomes much easier with practice, and this improvement was not found for the single component task, or for conjunctive tasks where the components cannot be unitized. Influences of component order (Experiment 1), component contiguity (Experiment 2), component proximity (Experiment 3), and number of components (Experiment 4) on practice effects were found. Using a Fourier Transformation method for deconvolving response times (Experiment 5), prolonged practice effects yielded responses that were faster than expected by analytic model that integrate evidence from independently perceived components

The effect of multiple knowledge sources on learning and teaching

Current paradigms for machine-based learning and teaching tend to perform their task in isolation from a rich context of existing knowledge. In contrast, the research project presented here takes the view that bringing multiple sources of knowledge to bear is of central importance to learning in complex domains. As a consequence teaching must both take advantage of and beware of interactions between new and existing knowledge. The central process which connects learning to its context is reasoning by analogy, a primary concern of this research. In teaching, the connection is provided by the explicit use of a learning model to reason about the choice of teaching actions. In this learning paradigm, new concepts are incrementally refined and integrated into a body of expertise, rather than being evaluated against a static notion of correctness. The domain chosen for this experimentation is that of learning to solve "algebra story problems." A model of acquiring problem solving skills in this domain is described, including: representational structures for background knowledge, a problem solving architecture, learning mechanisms, and the role of analogies in applying existing problem solving abilities to novel problems. Examples of learning are given for representative instances of algebra story problems. After relating our views to the psychological literature, we outline the design of a teaching system. Finally, we insist on the interdependence of learning and teaching and on the synergistic effects of conducting both research efforts in parallel

FROM LANGUAGE TO LITERACY: STRUCTURAL FEATURES OF ACQUIRED LANGUAGES FACILITATING ENGLISH MORPHOLOGICAL AWARENESS

Morphological awareness is a crucial metalinguistic skill, specifically for English Language Learners (ELLs). Since languages differ widely in degree of orthographic opacity, degree of morphological fusion, and degree of morphological synthesis, this thesis sought to evaluate the impact of the structural features of other languages upon ELLs’ levels of English morphological awareness. Additionally, the study investigated the relationship between morphological awareness and perceived levels of literacy and oracy proficiency. Multilingual individuals responded to an online survey containing a morphological awareness task and a language history questionnaire. Each language represented in the sample was coded according to its structural features. Subsequently, the relationship between the features and morphological awareness was analyzed. Morphological awareness was impacted by a confluence of all three structural features. Knowledge of languages with higher degrees of morphological synthesis or higher degrees of orthographic opacity was found to predict higher levels of morphological awareness. Additionally, perceived English literacy proficiency explained a larger degree of the variance in English morphological awareness than perceived English oracy proficiency, though both were statistically significant. The findings indicate the acquisition of English may be impacted by familiarity with other languages and by perceptions of English proficienc

The Development of Orthographic Knowledge: A Cognitive Neuroscience Investigation of Reading Skill

This investigation compared the effects of explicit letter-sound training to holistic word training on the development of word recognition in a novel orthography paradigm. In a between-subjects design, participants were trained to read spoken English words printed in the alphabet script of Korean Hangul. Training took place over four separate sessions with assessment measures conducted throughout. Compared to the holistic training, the component training condition resulted in significantly better transfer to novel word forms and retention of previously learned items. Furthermore, compared to component training, holistic training yielded greater sensitivity to frequency. Variability in the holistically trained condition revealed bimodal distribution of performance: a high and low performing subset. Functional MRI measured cortical responses to the training conditions. Imaging results revealed generally greater responses in the "reading network" overall for the explicit component-based training compared to holistic training, in particular, regions of the inferior and superior parietal gyri as well as the left precentral gyrus. In a comparison of readers within the holistic group, we found that readers who implicitly derived the sublexical patterns in the writing system activated more of the reading network than those who did not sufficiently acquire this knowledge. This latter group primarily activated ventral visual regions. We conclude that explicit training of sublexical components leads to optimal word recognition performance in alphabetic writing systems due to the redundant mechanisms of decoding and specific word form knowledge

Parental Reflective Functioning and Children’s Emergent Reading Skills: ERP and longitudinal behavioral measures

The current study examined the correlations between parental reflective functioning and children’s phonological awareness and reading-related neural development (measured via a phoneme-processing experiment using EEG), and its utility as a predictor of children’s reading skills one year later when they have begun literacy education. Fourteen pre-readers’ (mean age 4.51 years) phonological awareness and their parents’ reflective functioning skills were assessed, along with their EEG responses in a phoneme- processing task. Children’s phonological awareness and emergent reading skills were assessed again 12-15 months later, at the start of First Grade. Left-lateralized neural indices were observed to be correlated with parental reflective functioning (PRF) and children’s later reading-related skills. Specifically, scores on measures of PRF: Interest & Curiosity were positively correlated with the N2 amplitude in the left temporal cortex (p = 0.049), and the P2 amplitude in the left temporal cortex was also correlated with children’s Phonological Awareness scores (p = 0.004) and with their Basic Reading scores (p = 0.002) one year later. Multiple linear regression analyses also revealed that scores on measures of PRF: Interest and Curiosity significantly predicted children’s future phonological awareness (p = 0.014) and basic reading skills (p = 0.002). This study is the first of its kind to identify correlations between parental engagement and neural indices of children’s pre-reading skills, and to reveal parental reflective functioning as a strong predictor of children’s later reading abilities

Fractals in the Nervous System: conceptual Implications for Theoretical Neuroscience

This essay is presented with two principal objectives in mind: first, to document the prevalence of fractals at all levels of the nervous system, giving credence to the notion of their functional relevance; and second, to draw attention to the as yet still unresolved issues of the detailed relationships among power law scaling, self-similarity, and self-organized criticality. As regards criticality, I will document that it has become a pivotal reference point in Neurodynamics. Furthermore, I will emphasize the not yet fully appreciated significance of allometric control processes. For dynamic fractals, I will assemble reasons for attributing to them the capacity to adapt task execution to contextual changes across a range of scales. The final Section consists of general reflections on the implications of the reviewed data, and identifies what appear to be issues of fundamental importance for future research in the rapidly evolving topic of this review

Facial expression recognition and the autism spectrum

An atypical recognition of facial expressions of emotion is thought to be part of the characteristics associated with an autism spectrum disorder diagnosis (DSM-5, 2013). However, despite over three decades of experimental research into facial expression recognition (FER) in autism spectrum disorder (ASD), conflicting results are still reported (Harms, Martin, and Wallace, 2010). The thesis presented here aims to explore FER in ASD using novel techniques, as well as assessing the contribution of a co-occurring emotion-blindness condition (alexithymia) and autism-like personality traits. Chapter 1 provides a review of the current literature surrounding emotion perception in ASD, focussing specifically on evidence for, and against, atypical recognition of facial expressions of emotion in ASD. The experimental chapters presented in this thesis (Chapters 2, 3 and 4) explore FER in adults with ASD, children with ASD and in the wider, typical population. In Chapter 2, a novel psychophysics method is presented along with its use in assessing FER in individuals with ASD. Chapter 2 also presents a research experiment in adults with ASD, indicating that FER is similar compared to typically developed (TD) adults in terms of the facial muscle components (action units; AUs), the intensity levels and the timing components utilised from the stimuli. In addition to this, individual differences within groups are shown, indicating that better FER ability is associated with lower levels of ASD symptoms in adults with ASD (measured using the ADOS; Lord et al. (2000)) and lower levels of autism-like personality traits in TD adults (measured using the Autism-Spectrum Quotient; (S. Baron-Cohen, Wheelwright, Skinner, Martin, and Clubley, 2001)). Similarly, Chapter 3 indicates that children with ASD are not significantly different from TD children in their perception of facial expressions of emotion as assessed using AU, intensity and timing components. Chapter 4 assesses the contribution of alexithymia and autism-like personality traits (AQ) to FER ability in a sample of individuals from the typical population. This chapter provides evidence against the idea that alexithymia levels predict FER ability over and above AQ levels. The importance of the aforementioned results are discussed in Chapter 5 in the context of previous research in the field, and in relation to established theoretical approaches to FER in ASD. In particular, arguments are made that FER cannot be conceptualised under an ‘all-or-nothing’ framework, which has been implied for a number of years (Harms et al., 2010). Instead it is proposed that FER is a multifaceted skill in individuals with ASD, which varies according to an individual’s skillset. Lastly, limitations of the research presented in this thesis are discussed in addition to suggestions for future research

Neuromuscular Markers of High Performance Sport Preparation: Muscle Contractile Mechanics

Assessments of skeletal muscle functional capacity or bilateral muscular asymmetry often necessitate maximal contractile effort, which exacerbates muscle fatigue or injury. Tensiomyography (TMG) has been investigated in laboratory settings, as a means to assess muscle contractile function following fatigue; however observations have not been contextualised by concurrent physiological measures. TMG has more sparingly been applied in the field, with elite athletes. The aim of this thesis was to examine acute alterations and underlying variations in muscle contractile mechanics, through the application of TMG, contextualised with established physiological measures; and to apply TMG within high performance sports programmes. TMG successfully detected fatigue, evident from reduced strength, by displaying impaired muscle displacement, accompanied by elevated resting muscle tension. Greater asymmetry was detected in individuals with asymmetric strength; however, symmetry was masked during more complex tasks. Increased day-to-day variability was detected among highly trained athletes compared to recreationally active individuals. Acute training adaptations were detected, in contractile mechanics, in individual muscles. TMG could be useful in establishing fatigue status of skeletal muscle without exacerbating the functional decrements of the muscle, whilst also providing useful screening information for detecting asymmetry which may not be apparent during functional actions