Complex-Valued Time-Series Correlation Increases Sensitivity in FMRI Analysis

Purpose To develop a linear matrix representation of correlation between complex-valued (CV) time-series in the temporal Fourier frequency domain, and demonstrate its increased sensitivity over correlation between magnitude-only (MO) time-series in functional MRI (fMRI) analysis. Materials and Methods The standard in fMRI is to discard the phase before the statistical analysis of the data, despite evidence of task related change in the phase time-series. With a real-valued isomorphism representation of Fourier reconstruction, correlation is computed in the temporal frequency domain with CV time-series data, rather than with the standard of MO data. A MATLAB simulation compares the Fisher-z transform of MO and CV correlations for varying degrees of task related magnitude and phase amplitude change in the time-series. The increased sensitivity of the complex-valued Fourier representation of correlation is also demonstrated with experimental human data. Since the correlation description in the temporal frequency domain is represented as a summation of second order temporal frequencies, the correlation is easily divided into experimentally relevant frequency bands for each voxel\u27s temporal frequency spectrum. The MO and CV correlations for the experimental human data are analyzed for four voxels of interest (VOIs) to show the framework with high and low contrast-to-noise ratios in the motor cortex and the supplementary motor cortex. Results The simulation demonstrates the increased strength of CV correlations over MO correlations for low magnitude contrast-to-noise time-series. In the experimental human data, the MO correlation maps are noisier than the CV maps, and it is more difficult to distinguish the motor cortex in the MO correlation maps after spatial processing. Conclusions Including both magnitude and phase in the spatial correlation computations more accurately defines the correlated left and right motor cortices. Sensitivity in correlation analysis is important to preserve the signal of interest in fMRI data sets with high noise variance, and avoid excessive processing induced correlation

Return to Self: Impact of Long Term Acquired Brain Injury Rehabilitation on Community Reintegration

The purpose of this study is to examine the outcomes of a long term brain injury rehabilitation program and its impact on community re-integration. This unique facility is licensed as a Long-Term Care Facility, able to provide longer lengths of stay to treat medical and psychological needs. All residents of this facility have a diagnosis of Acquired Brain Injury (ABI) as well as a mental illness. The mental illness may have existed prior to the brain injury, or may have arisen or worsened as a result of the brain injury. This program combines traditional rehabilitation therapy (Physical Therapy, Occupational Therapy, Speech Therapy, and Recreational Therapy) with skilled psychological services to provide holistic treatment of ABI. Quantitative assessment results were collected on a data form and combined with therapist observation via facility documentation to obtain the results of the study. Residents\u27 skills, behaviors, and rehabilitation progress were observed in group therapy settings, individual therapy settings, and community outings. Assessment outcomes from admission to discharge were analyzed through statistical analysis. The hypothesis is that outcomes data and therapist feedback will show that this program improves functional abilities of individuals with ABI and provides them with the skills to successfully transition to a lower level of care

Experiencing contemporary arts organisations in rural places : arts practices and disruption in North East England and Scotland

PhD ThesisThe research explores contemporary visual arts organisations and their arts practices. Taking recent frameworks of cultural value as a point of departure, it focuses on how these practices are experienced. It asks how might these practices impact rural people and places, and disrupt rural identities? The research employed exploratory case studies of three contemporary visual arts organisations and their arts practices in rural locations in England and Scotland. It focussed on ‘moments’ of disruption in each location through specific arts projects, and how these were experienced by different actors. Qualitative data were collected through in-depth interviews, along with analysis of texts and items of visual material such as video and photographs. This was complemented by participant observation of the arts organisations ‘at work’ in each location. The research found that contemporary arts organisations are positioned within a creative practice of ‘the post-studio, site responsive artist and roving global curator’. As neo-endogenous cultural actors, they are networked extra locally, yet remain responsive to rural place and context in distinctive ways. The research suggests a continuing struggle over the ways in which cultural identities of place in the rural are disrupted and maintained. It further reveals the processes of change and resistance implicit in the creation of cultural place identities, and in the maintenance of actors’ sense of place. It suggests an ongoing tension between constructions of the rural as traditional and modern, with contemporary arts practices seen by some as urban signifiers of modernity, and ‘out of place’ in the countryside. For others, they were ‘in place’, markers of cultural diversity that reinforced their identities as culturally literate actors, and enhanced their sense of place. The findings suggest an interpretation of the rural as a site of dynamic cultural change alongside more traditional cultural practices and perspectives

But That\u27s Where My Books Are! : Adults Who Read Young Adult Literature

This narrative instrumental case study seeks to understand why adults (age 30+) read young adult literature (YAL) and how adults engage with the genre. Additionally, this study seeks to interpret how the genre influences adult identities. Though YAL is typically written by adults for adolescents age 12-18 (Cart, 2008; Cole, 2009), the adult readers in this study preferred reading YAL more than other genres of literature. Using both reader response theory and socio-emotional conceptualizations of reading engagement and identity as theoretical and analytical frameworks, the aim of this study is to understand why adult participants preferred this genre, and what, if anything, they gained from reading YAL. Specifically seeking to understand: ● What are the rationales adults (age 30+) provide for reading YAL? ● In what ways do adults (age 30+) engage with YAL?● How does the genre of YAL influence adult reader identities? This qualitative study draws on both narrative inquiry (Clandinin & Connelly, 2000) and instrumental case study (Stake, 2006), and employs adult participants’ narratives about their experiences reading YAL to elaborate on the greater phenomenon of adults who read YAL for pleasure. The findings of this study suggest the adults engage with YAL through characters, situations, and worlds, utilizing YAL as a simulation tool to insert themselves into the given worlds or situations presented in YAL texts. Additionally, adults in this study cited YAL texts they read as influential on their behaviors, actions, feelings, and intentions, which is indicative of the dynamic, socially constructed nature of identity, rather than a developmental or essentialized construct of identity as the literature purports

Impacts of Simultaneous Multislice Acquisition on Sensitivity and Specificity in fMRI

Simultaneous multislice (SMS) imaging can be used to decrease the time between acquisition of fMRI volumes, which can increase sensitivity by facilitating the removal of higher-frequency artifacts and boosting effective sample size. The technique requires an additional processing step in which the slices are separated, or unaliased, to recover the whole brain volume. However, this may result in signal “leakage” between aliased locations, i.e., slice “leakage,” and lead to spurious activation (decreased specificity). SMS can also lead to noise amplification, which can reduce the benefits of decreased repetition time. In this study, we evaluate the original slice-GRAPPA (no leak block) reconstruction algorithmand acceleration factor (AF = 8) used in the fMRI data in the young adult Human Connectome Project (HCP). We also evaluate split slice-GRAPPA (leak block), which can reduce slice leakage. We use simulations to disentangle higher test statistics into true positives (sensitivity) and false positives (decreased specificity). Slice leakage was greatly decreased by split slice-GRAPPA. Noise amplification was decreased by using moderate acceleration factors (AF = 4). We examined slice leakage in unprocessed fMRI motor task data from the HCP. When data were smoothed, we found evidence of slice leakage in some, but not all, subjects. We also found evidence of SMS noise amplification in unprocessed task and processed resting-state HCP data

Organizational Ombuds surveys, 1970s to 1990s

Portions of this file are not available online at the request of the creator. For more information about this item, visit https://archivesspace.mit.edu/repositories/2/archival_objects/30985

University of Colorado Ombudsman study, 1985

Portions of this file are not available online at the request of the creator. For more information about this item, visit https://archivesspace.mit.edu/repositories/2/archival_objects/30254

Analyzing Your Conflict Management System, 2014

For more information about this item, visit https://archivesspace.mit.edu/repositories/2/archival_objects/31003

Directory, College and University Ombudsmen and Others, 1990-1991

For more information about this item, visit https://archivesspace.mit.edu/repositories/2/archival_objects/30328