Year: 2018
Type: dissertation
Abstract: Abnormal behaviour may be a warning sign of underlying brain disease. Neuropsychological (NP) tests - behavioural tasks that very commonly involve handwriting and drawing - are widely used in the clinic to detect abnormal brain function in a variety of brain diseases. Task-based functional magnetic resonance imaging (fMRI), a method for noninvasively mapping the brain activity that underlies specific behaviours, can possibly help to inform use of NP tests, and to improve their sensitivity and specificity. Task-based fMRI typically involves peripheral devices that are used to present sensory stimuli and record behavioural responses. Such devices (e.g. video projectors, key pads for detecting button presses) must be designed for compatibility with fMRI procedures, including operation at the very high magnetic field of the MRI system without introducing electromagnetic interference. The common fMRI-compatible devices are insufficient for evaluating many NP tests, however. Consequently, an fMRI-compatible tablet, including a touch-sensitive surface, was developed in the Graham laboratory to enable fMRI studies of NP tests that involve writing and drawing responses. In its original prototype, the tablet did not enable individuals to see their hand while performing writing and drawing actions. This missing feature, termed “visual feedback of hand position” (VFHP), may make it difficult for certain patient populations to interact easily with the tablet during task-based fMRI. The interactivity of the tablet thus should be improved before proceeding to map the brain activity of specific NP tests. This thesis focuses on developing a real-time system to integrate VFHP with the tablet in an augmented reality display, including simple computer graphics to present visual stimuli and tablet responses, and merged streaming video of the hand as it manipulates a stylus during writing and drawing behaviour. First, the new tablet prototype is developed and validated in the context of a writing task that involves copying sentences, showing that tablet interactivity is enhanced when VFHP is included. Second, the prototype is used to perform the first characterization of the brain activity in a control population of young healthy adults as they perform a novel NP test that was specially designed to detect and evaluate writing impairments in patients with Mild Cognitive Impairment and Alzheimer’s Disease. Third, the impact of adopting the tablet with and without VFHP is studied for a group of young healthy adults as they undergo fMRI while performing the trail making test (TMT), an NP test that is commonly used to assess the frontal lobes of the brain. Finally, future directions of this research are discussed, including use of this new tablet technology to assess patients with brain diseases in task-based fMRI trials.
Source: TSpace (University of Toronto)
Author: Mahta Karimpoor
Language: English
Subfield: Human-Computer Interaction
Field: Computer Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W3136493390