Skip to main content
eScholarship
Open Access Publications from the University of California

Scholarly Works (4 results)

  • Thesis
  • Peer Reviewed
UC Riverside Electronic Theses and Dissertations (2012)

The population over the age of 65 years old is rapidly increasing around the world. Presbycusis (age-related hearing loss) is one of the most prevalent disabilities associated with age and can impair speech understanding and social and emotional well-being. Deficits in auditory processing, including speech understanding are likely caused by an interaction between changes in the way the brain processes sound and peripheral sensory hearing loss. It is difficult to disambiguate changes that occur within the brain independent of peripheral hearing loss and those that change because of it. To that end, this dissertation provides a framework for beginning to tease out how the relative contributions of peripheral sensory hearing loss (loss of cochlear hair cells) on cortical processing of frequency modulated (FM) sweeps in a mouse model of presbycusis (strain C57/bl6). FM sweeps are sounds that change in frequency over time. Human language and animal vocalizations contain FM sweeps. The genetic engineering tools present in the mouse make it a suitable model for probing the genetic roots and underlying mechanisms of neural dysfunction, such as is seen in presbycusis.

This C57/bl6 mouse strain undergoes predictable high frequency hearing loss by 6 months of age, continuing to profound hearing loss by 12 months of age. The purpose of this dissertation was to establish cortical response properties to FM sweeps as a function of age in a mouse model of presbycusis. Three experiments were performed. In the first experiment, FM sweep response properties were profiled in the young adult core auditory cortex. The main findings of the first experiment indicate that the young adult mouse auditory cortex is selective for a narrow range of FM sweep rates (between 0.5 and 3 kHz/msec) and this selectivity is depth dependent, suggesting FM sweep processing undergoes changes within the a cortical column. The second experiment explored the mechanisms that shape FM sweep rate selectivity. The main findings of the second experiment were that two mechanisms shape FM sweep rate selectivity in the young adult cortex, duration tuning for tones and sideband inhibition. Sideband inhibition is the dominant mechanism in the auditory cortex, shaping FM sweep rate selectivity in approximately 84% of neurons tested. Duration tuning shaped FM sweep rate selectivity in approximately 34% of neurons tested. The third experiment compared direction selectivity, FM rate selectivity, variability, and mechanisms between three age groups, young (1 - 3 months), middle (6-8 months), and old (14 - 20 months). The main findings of the third experiment were that presbycusis results in decreased selectivity, slowed FM rate selectivity, increased variability and decreased reliance on sideband inhibition. The results of these studies serve as a framework for comparisons with mouse strains who do not experience age-related hearing loss.

    Cover page: Cortical Processing of Frequency Modulated Sweeps in a Mouse Model of Presbycusis
    • Article
    • Peer Reviewed
    UC San Francisco Previously Published Works (2021)
    Abstract: Sexual minority is an umbrella term used to describe individuals who identify as lesbian, gay, bisexual, or queer and/or engage in sexual behavior with individuals of the same sex or gender. Drawing on previous models (Hatzenbuehler, 2009; Major et al., 2013; Meyer, 2003; Ryan et al., 2017) and social psychological theory, this article outlines the social and health consequences of the stigma associated with being a sexual minority and the societal, social, and intrapersonal factors that might lead to these health and social disparities. We highlight key responses to stigmatization such as physiological responses, affect, and behavioral reactions that may contribute directly and/or indirectly to health outcomes. In doing so, we propose that the stigma of sexual minority identity, manifested at multiple levels, is associated with disparities in health and social outcomes and that social psychology can provide a useful lens to begin to reduce health disparities.
      Cover page: An ignored minority status: Consequences for sexual minorities living in a biased societyCreative Commons 'BY' version 4.0 license
      • Article
      • Peer Reviewed
      UCLA Previously Published Works (2024)

      Background

      Chronic pain has long been a major health burden that has been addressed through numerous forms of pharmacological and nonpharmacological treatment. One of the tenets of modern medicine is to minimize risk while providing efficacy. Further, because of its noninvasive nature, virtual reality (VR) provides an attractive platform for potentially developing novel therapeutic modalities.

      Objective

      The purpose of this study was to determine the feasibility of a novel VR-based digital therapy for the treatment of chronic pain.

      Methods

      An open-label study assessed the feasibility of using virtual embodiment in VR to treat chronic pain. In total, 24 patients with chronic pain were recruited from local pain clinics and completed 8 sessions of a novel digital therapeutic that combines virtual embodiment with graded motor imagery to deliver functional rehabilitation exercises over the course of 4 weeks. Pain intensity as measured by a visual analog scale before and after each virtual embodiment training session was used as the primary outcome measure. Additionally, a battery of patient-reported pain questionnaires (Fear-Avoidance Beliefs Questionnaire, Oswestry Low Back Pain Disability Questionnaire, Pain Catastrophizing Scale, and Patient Health Questionnaire) were administered before and after 8 sessions of virtual embodiment training as exploratory outcome measures to assess if the measures are appropriate and warrant a larger randomized controlled trial.

      Results

      A 2-way ANOVA on session × pre- versus postvirtual embodiment training revealed that individual virtual embodiment training sessions significantly reduced the intensity of pain as measured by the visual analog scale (P<.001). Perceived disability due to lower back pain as measured by the Oswestry Low Back Pain Disability Questionnaire significantly improved (P=.003) over the 4-week course of virtual embodiment regimen. Improvement was also observed on the helplessness subscale of the Pain Catastrophizing Scale (P=.02).

      Conclusions

      This study provides evidence that functional rehabilitation exercises delivered in VR are safe and may have positive effects on alleviating the symptoms of chronic pain. Additionally, the virtual embodiment intervention may improve perceived disability and helplessness of patients with chronic pain after 8 sessions. The results support the justification for a larger randomized controlled trial to assess the extent to which virtual embodiment training can exert an effect on symptoms associated with chronic pain.

      Trial registration

      ClinicalTrials.gov NCT04060875; https://clinicaltrials.gov/ct2/show/NCT04060875.
        Cover page: The Effects of Embodiment in Virtual Reality for Treatment of Chronic Pain: A Feasibility Study (Preprint)
        • Article
        • Peer Reviewed
        UC San Francisco Previously Published Works (2022)
        Legislation has been passed in some states to reduce discrimination and victimization toward sexual and gender minority people (SGM; people who are not solely heterosexual and/or whose gender identity is not equal to what is socially associated with sex assigned at birth). The purpose of these analyses is to test whether state-level policy environments are associated with past-year discrimination and victimization among SGM people. Cross-sectional data from The Population Research in Identity and Disparities for Equality (PRIDE) Study annual questionnaire (collected 2018−2019), a national study of the health of SGM adults in the USA, were used for these analyses. Measures included related to discrimination, victimization, and demographic characteristics. State-level policy environments were measured using data from the Movement Advancement Project. Logistic regression analyses evaluated state-level policy environment scores and past-year discrimination and victimization among gender identity categories. In this sample, 7044 people (gender minority n = 2530) were included. Cisgender sexual minority (odds ratio [OR] = 1.007, p = 0.041) and the gender expansive subgroup of gender minority people (OR = 1.010, p = 0.047) in states with more protective policy environments had greater odds of discrimination. The gender expansive subgroup was found to have greater odds of victimization in states with more protective policy environments (OR = 1.003, p < 0.05). There was no relationship between state-level policy environments and victimization among any other study groups. SGM people may experience increased risk for discrimination and victimization despite legislative protections, posing continued risks for poor health outcomes and marginalization. Evaluation of factors (e.g., implementation strategies, systems of accountability) that influence the effectiveness of state-level polices on the reported experiences of discrimination and victimization among SGM people is needed.
          Cover page: State-Level Policy Environments, Discrimination, and Victimization among Sexual and Gender Minority People
          Top