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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Using eye tracking to examine a single word copying paradigm

Laishley, Abby Emma January 2017 (has links)
Classroom learning, the bedrock of school education, relies heavily on written information transfer. The seemingly simple task of copying text from a board is psychologically complex and involves sequential visual and cognitive processes: visual encoding, constructing and maintaining mental representations, and written production. To date, most research in this area has focused on written production. This Thesis aimed to quantify what linguistic units copiers activated during visual encoding; whether similar units were used during encoding and production; and whether copiers whose reading ability was still developing, encoded and produced words in a similar fashion to copiers with fully developed reading ability. New mobile eyetracking technology enabled recording of eye-movement behaviour as an indicator of cognitive processing over both visual encoding and written production. In two experiments, both adults’ and children’s eye-movements were recorded as they made handwritten copies of single words presented on a classroom board. Gaze time measures showed both adults and children encoded whole word and syllable units, though this was not consistent for children processing long words. For all copiers, written production was often based on comparatively smaller units than encoding. Also, children needed more gaze lifts between the written copy and the board than adults, suggesting they relied more on piecemeal linguistic representations of subword units, perhaps because of forgetting. An additional lexical decision experiment showed how children could encode long words as whole word units, suggesting that piecemeal encoding of subword units might be restricted to a copying task, that includes additional task demands associated with mental representation and written production processes as well as visual encoding. Word copying relied on systematic linguistic units, but the size of a unit appeared to modulate its functionality differently for encoding and production, even for skilled readers. Findings guided development of a theoretical framework for the copying process.
22

A comparative investigation of generalization processes

Hunter, Ian Melville Logan January 1953 (has links)
No description available.
23

Interceptive actions in adults and children

Giles, Oscar Terence January 2017 (has links)
Interceptive actions refer to goal directed movements in which people attempt to make a controlled collision with a moving object (e.g. catching a ball). Because interceptive actions often take place under severe temporal constraints, movements need to be executed with exquisite temporal accuracy and precision. To achieve this the sensorimotor system needs to: (i) accurately predict the motion of the target object, and (ii) move the intercepting effector (e.g. hand, bat) to a location through which the object will pass at just the right time. This presents the sensorimotor system with numerous computational challenges. Examining interceptive timing in adults provides insights into how these challenges are overcome in the developed sensorimotor system, while studying children can reveal how these abilities are acquired and how they are related to the development of other sensorimotor and cognitive processes. The first part of this thesis investigates the control of interceptive timing behaviours in adults. Chapter 3 provides evidence that online sensory information is combined with a-priori knowledge, using Bayesian integration, to optimise movement timing. Chapter 4 demonstrates that adults optimally time their movements to exploit a physical relationship between the speed and temporal precision of their movements. The second part of this thesis then examines interceptive timing abilities in children. Chapter 5 documents the developmental trajectory of interceptive timing abilities over childhood, revealing that performance is still far from adult levels by the time children finish primary school (age 11 years). Chapter 6 tests a common taxonomy of motor skills, revealing that interceptive timing tasks measure a somewhat distinct ‘motor construct’ from that measured by ‘fine’ and ‘gross’ motor tasks. Finally, chapter 7 reveals a relationship between interceptive timing abilities and academic attainment in mathematics, even after controlling for motor skills in other taxonomic domains. Together these experiments shed light on how humans are able to exquisitely time interceptive actions, and provide key insights into the ontogeny of this fundamental motor ability.
24

Language-Mediated Event Representations

Williams, Glenn P. January 2016 (has links)
When understanding narrative events we must keep track of a number of (often) changing dimensions, such as who is the focus of the narrative, what they are doing, and where they are doing it; amongst which, this ‘where’ dimension is thought to be crucial in forming even the simplest representation of events. Thus, in order to understand how we represent events, research has often focused upon how we represent space. While research from the spatial cognition and language comprehension literature has shown that we can form a mental representation of space that is rich in detail, maintaining categorical (i.e. room-by-room) as well as Euclidean distance (i.e. absolute distance), this research has primarily used tasks which may bias towards one representation over another. Thus, the research presented in this thesis set out to explore which representation of space is maintained in the absence of an overt task, and the implications that this representation has for the organisation and accessibility for information maintained in a mental representation of events (or, an ‘event model’). Using eye-tracking methods and ‘look-and-listen’ tasks in the visual world paradigm throughout to explore how manipulations of space influence accessibility for objects – in terms of fixations on objects depicted in a visual display during language comprehension – the experiments laid out in the present thesis found that comprehenders spontaneously form a categorical (but not Euclidean) representation of space, constructing and maintaining separate ‘event models’ based around spatial units (e.g. rooms) in which information (e.g. objects) is maintained. While Experiment 1 found no influence of space on accessibility for the target on mention using a concurrent viewing and listening paradigm, by replacing the visual scene with a blank-screen prior to the onset of the narrative, Experiment 2 established that, during narrative comprehension, following the movement of a protagonist from one location to another, potential targets located in the initial location were less accessible prior to mention for the target. Experiment 3 explored the locus of this effect and found that, on mention, targets were less accessible following a spatial shift, regardless of whether the objects were in the same or a separate location to the protagonist. Experiments 4-6 built upon Experiments 1-3 to further explore how a spatial shift made by an object (carried by a protagonist) can modulate the structure of events, asking how access for a target is resolved when associated with two event models (vs. one event model). Here, visual scenes depicted two rooms, containing several objects, separated by a boundary. Narratives described an object moving from one location to another with a protagonist, necessitating movement across the boundary (or not). The most reliable finding was that both representations of the moved object were less accessible on mention when associated with two event models (vs. one event model), suggesting that competition occurs between event models prior to access for a target if the target is represented across more than one event model. Experiment 7 aimed to address how event structure can increase, rather than reduce accessibility for a target. Here, discourses separating a target into a different event model (vs. the same event model) to that of a semantically-related competitor increased accessibility for the target on mention and reduced accessibility for the competitor, suggesting that information in an accessed (foregrounded) event model is more accessible than information in other (backgrounded) event models. Together, the findings of the conducted experiments support the notion that comprehenders form and use event models in discourse comprehension when necessary during passive listening tasks, and that the form and structure of these event models modulates accessibility for information when doing so. The experiments established here have further supported and built upon general models of event cognition, establishing how and when event models, and the information maintained within them, are accessed.
25

The neural basis of expert anticipation in a real-world skill

Denis, Dan January 2016 (has links)
In many sports such as tennis, football, and basketball, the ability to anticipate the actions of an opponent is a key component of expert performance. Behavioural research has shown that expert athletes are able to identify and comprehend anticipatory cues present in the kinematics of an opposing player and use them to anticipate the end goal of an action. The aim of the work reported here was to investigate the neural basis of this anticipation skill in athletes. Specifically, the thesis focuses on the role of the sensorimotor system in facilitating this ability, based on evidence showing that the sensorimotor system is involved in the understanding of other people’s actions. First, two behavioural experiments are presented showing the development of an anticipation test that is able to distinguish expert and novice participants based upon their response accuracy. Then the role of sensorimotor activity in facilitating anticipation skill is investigated using EEG. Event-related power changes in cortical sensorimotor oscillations in the mu (8-13Hz) and beta (15-25Hz) frequency bands are used as indices of sensorimotor activity, based on the findings of previous work. It was found that earlier and greater event-related desynchronisation (ERD) occurred in the expert group, compared to the novices, in both the mu and beta frequency bands. This suggests greater use of the sensorimotor system during action anticipation in athletes, whilst viewing domain specific actions. However, traditional channel-based analyses of this measure are flawed in that volume conduction effects mean mu and non-mu alpha activity can become mixed. This means it is unclear the extent to which mu activity specifically indexes the sensorimotor system, as opposed to other processes such as attentional demand. As a potential solution to this issue, the data was re-analysed using independent component analysis (ICA) to separate out the underlying brain processes ongoing during the anticipation task. Expertise-related differences in mu and beta ERD were then analysed on independent component (IC) activity. The ICA analysis largely replicated the channel analysis, with earlier and greater ERD in expert athletes in ICs relating the sensorimotor activity. No group differences were found in ICs relating to non-mu, alpha activity. This suggests group differences were specific to sensorimotor activity, providing evidence that sensorimotor activity is key in distinguishing expert from novice athletes on an action anticipation task. In Chapter 5, a novel analysis method was used. Mu and beta ERD in the two groups were contrasted between trials that were subsequently anticipated correctly versus trials that were subsequently anticipated incorrectly. In the experienced group only, it was found that there was greater beta ERD for correctly anticipated trials compared to incorrectly anticipated trials. There were no differences in mu ERD between correct and incorrect trials. Furthermore, overall mu and beta ERD significantly negatively correlated with anticipation accuracy in the experienced group, suggesting a higher accuracy is associated with greater sensorimotor ERD during prior observation. Finally, in Chapter 6 the results are summarised and their implications within the wider literature considered, as well as a discussion of limitations and future directions.
26

Rethinking emotion : new research in emotion and recent debates in cognitive science

Evans, Dylan January 2000 (has links)
Cognitive science is currently the scene of a number of exciting debates. The so-called 'classical' approach, which has dominated the field since the 1950s, is increasingly being challenged on various fronts. Evolutionary psychologists and researchers in artificial life accuse classical cognitive scientists of ignoring the fact that natural cognition is not designed to solve abstract problems and prove theorems but to solve particular adaptive problems. Those working with a 'situated' view of the mind are challenging the classical commitment to internalism. Finally, proponents of dynamical approaches claim that the discrete models favoured by the classical approach are too coarse-grained and impute too much internal structure to the mind. In this thesis I argue that the 'non-classical' approaches are compatible with classical cognitive science, with the important proviso that compatibility comes in different kinds. In the final chapter I outline a vision of a comprehensive 'integrated non-classical cognitive science' that combines the three non-classical approaches into a single conceptual bundle. I illustrate these claims about cognitive science in general with reference to a particular field of research: the emotions. Emotions were ignored by most classical cognitive scientists, though some models of emotion were developed within the classical framework. These models, however, provided no way of distinguishing emotion from cognition. I argue that the non-classical approaches remedy this problem, and together provide a new way of thinking about the emotions which I dub 'the interruption theory'. Since the interruption theory borrows insights from all three of the non-classical forms of cognitive science, it serves as a good example of the integrated non-classical approach that I recommend for cognitive science in general.
27

Pragmatic influences on rule discovery in Wason's 2-4-6 task

Wade, Caroline Nicola January 2010 (has links)
The aim of the reported research was to investigate the determinants of poor performance on Wason's (1960) rule discovery task. Following the argument that the conversational pragmatics of the task cause reasoners to attach a presumption of relevance to the salient properties of the given 2-4-6 exemplar triple (Van der Henst, Rossi, & Schroyens, 2002), the first set of experiments set out to examine further the impact of perceived triple relevance on rule discovery. Although the results of these initial experiments did not rule out the possibility of a relevance effect, it was quickly established that the previous evidence used to support the relevance account was potentially confounded by other factors present within Van der Henst et al's experimental scenario. In establishing this conclusion, the question also arose as to whether participants can genuinely be assumed to be engaging in hypothesis testing when faced with Wason's 2-4-6 task instructions. It was subsequently proposed that the failure observed on the standard 2-4-6 task should not be attributed to a poor hypothesis testing strategy but rather to participants' misinterpretation of the task's intended objective. The final two experiments tested this idea by altering the task so as to emphasise the intended goal of discovering one of many possible rule alternatives. The subsequent results supported the proposed "misinterpreted objective account" of the standard 2-4-6 task in that clarifying the task's objective readily elicits genuine hypotheses testing behaviour, thereby promoting successful rule discovery. The thesis situates these findings within Evans' ( e.g., 2006) general hypothetical thinking framework and argues for a more positive view of people's hypothesis testing capacities than that which has previously stemmed from research employing Wason's rule discovery paradigm.
28

Task switching and cognitive control processes : measured using increases to stimulus dimension, stimulus set size and task practice

Breeze, Julian January 2008 (has links)
The aim of this thesis is to understand some of the processes involved in the selection of appropriate tasks, and in the selection of correct responses to those tasks. The main focus of the following experiments will be on how interference and conflict occurs during these processes, either at the perceptual or action selection stages when switching task. It should be possible to demonstrate with increases to the number of attributes, the experience of tasks associated with non-target attributes, and in varying the number of trials before switching tasks, that task selection consists of several stages or processes, and that these processes do not necessarily interact. This will show that the switch cost is not an unitary cost associated with changing a single response-stimulus setting, task parameter, or an overall task set, but a composite of various costs associated with different task selection processes.
29

Task switching and response processes

Cooper, Stephen January 2008 (has links)
When switching between tasks, participants are sometimes required to use different response sets for each task: So, task switch and response set switch are commonly confounded. Eleven experiments divided into three series examined transitions of response within a linear four-finger arrangement. The first series examined cued grouping by hand or finger equivalence in both single task and task switching designs. The second considered the effect upon transitions of response when full repetition of the stimulus was included in the design. Results showed that part of the task switch cost is associated with switching between response sets, particularly those of hand.
30

Brain markers of executive control in task management

Roberts, Adam C. January 2009 (has links)
The primary goal of the empirical research outlined in this thesis was to examine the role of the central executive in task management using EEG imaging methods. To achieve this goal, a series of experiments were conducted in order to determine decrements during complex task performance, and explore the relative contributions of executive fatigue and task load in the onset of compensatory control mechanisms which are said to manage goal directed activity. These experiments were based around a theoretical framework of neural correlates of Compensatory Control, drawing on evidence from imaging and psychophysiological studies. A laboratory-based complex process control task (aCAMS) was used to investigate the control of various life support systems, such as oxygen, pressure, carbon dioxide, humidity, and temperature in a simulated spaceship environment. The results of the automatic control experiment revealed no effect of fatigue, implicating a high level of goal protection. However, the results of the manual control experiment showed changes in many psychophysiological measures with load, with high inter-individual differences indicating the presence of different task strategies across operators. The results of more detailed analysis showed that, upon the examination of short-term changes, prefrontal theta response dropped in relation to task error reflecting a re-evaluation of task goals, and that this could be predicted based on the combination of prefrontal theta response and sub-optimal control strategies. The third and fourth experiments modified the task's primary operational criteria using adaptive automation, and found that it provided benefits in task performance, and automation interventions - changes in the level of automation, produced improved operator performance at individual levels of load. Taken together, these results demonstrate a number of ways that adaptive automation can be developed using psychophysiological markers of executive function.

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