Dementia is a syndrome resulting from an acquired brain disease that affects many domains of cognitive impairment. The progressive disorder generally affects memory, attention, executive functions, communication, and other cognitive domains that significantly alter everyday function (Quinn, 2014). The purpose of this research was to gather a systematic review of cognitive-communication assessments and screeners used in assessing dementia to assist in early prognosis. From this review, there is potential in developing a new test to address the areas that people with dementia often have deficits in 1) Memory, 2) Attention, 3) Executive Functions, 4) Language, and 5) Visuospatial Skills. In the field of speech-language pathology, or medicine in general, there is no one assessment that can diagnose dementia. Additionally, this review will explore identifying speech and language characteristics of dementia through speech analytics to theoretically help clinicians identify early signs of dementia.

With a growing number of adults with autism spectrum disorder (ASD), more and more research has been conducted on majority male cohorts with ASD from young, adolescence, and some older age. Currently, males make up the majority of individuals diagnosed with ASD, however, recent research states that the gender gap is closing due to more advanced screening and a better understanding of how females with ASD present their symptoms. Little research has been published on the neurocognitive differences that exist between older adults with ASD compared to neurotypical (NT) counterparts, and nothing has specifically addressed older women with ASD. This study utilized neuroimaging and neuropsychological tests to examine differences between diagnosis and sex of four distinct groups: older men with ASD, older women with ASD, older NT men, and older NT women. In each group, hippocampal size (via FreeSurfer) was analyzed for differences as well as correlations with neuropsychological tests. Participants (ASD Female, n = 12; NT Female, n = 14; ASD Male, n = 30; NT Male = 22), were similar according to age, IQ, and education. The results of the study indicated that the ASD Group as a whole performed worse on executive functioning tasks (Wisconsin Card Sorting Test, Trails Making Test) and memory-related tasks (Rey Auditory Verbal Learning Test, Weschler Memory Scale: Visual Reproduction) compared to the NT Group. Interactions of sex by diagnosis approached significance only within the WCST non-perseverative errors, with the women with ASD performing worse than NT women, but no group differences between men. Effect sizes between the female groups (ASD female vs. NT female) showed more than double that of the male groups (ASD male vs. NT male) for all WCST and AVLT measures. Participants with ASD had significantly smaller right hippocampal volumes than NT participants. In addition, all older women showed larger hippocampal volumes when corrected for total intracranial volume (TIV) compared to all older men. Overall, NT Females had significant correlations across all neuropsychological tests and their hippocampal volumes whereas no other group had significant correlations. These results suggest a tighter coupling between hippocampal size and cognition in NT Females than NT Males and both sexes with ASD. This study promotes further understanding of the neuropsychological differences between older men and women, both with and without ASD. Further research is needed on a larger sample of older women with and without ASD.

Older adults often experience communication difficulties, including poorer comprehension of auditory speech when it contains complex sentence structures or occurs in noisy environments. Previous work has linked cognitive abilities and the engagement of domain-general cognitive resources, such as the cingulo-opercular and frontoparietal brain networks, in response to challenging speech. However, the degree to which these networks can support comprehension remains unclear. Furthermore, how hearing loss may be related to the cognitive resources recruited during challenging speech comprehension is unknown. This dissertation investigated how hearing, cognitive performance, and functional brain networks contribute to challenging auditory speech comprehension in older adults. Experiment 1 characterized how age and hearing loss modulate resting-state functional connectivity between Heschl’s gyrus and several sensory and cognitive brain networks. The results indicate that older adults exhibit decreased functional connectivity between Heschl’s gyrus and sensory and attention networks compared to younger adults. Within older adults, greater hearing loss was associated with increased functional connectivity between right Heschl’s gyrus and the cingulo-opercular and language networks. Experiments 2 and 3 investigated how hearing, working memory, attentional control, and fMRI measures predict comprehension of complex sentence structures and speech in noisy environments. Experiment 2 utilized resting-state functional magnetic resonance imaging (fMRI) and behavioral measures of working memory and attentional control. Experiment 3 used activation-based fMRI to examine the brain regions recruited in response to sentences with both complex structures and in noisy background environments as a function of hearing and cognitive abilities. The results suggest that working memory abilities and the functionality of the frontoparietal and language networks support the comprehension of speech in multi-speaker environments. Conversely, attentional control and the cingulo-opercular network were shown to support comprehension of complex sentence structures. Hearing loss was shown to decrease activation within right Heschl’s gyrus in response to all sentence conditions and increase activation within frontoparietal and cingulo-opercular regions. Hearing loss also was associated with poorer sentence comprehension in energetic, but not informational, masking. Together, these three experiments identify the unique contributions of cognition and brain networks that support challenging auditory speech comprehension in older adults, further probing how hearing loss affects these relationships.

Cognitive deficits often accompany language impairments post-stroke. Past research has focused on working memory in aphasia, but attention is largely underexplored. Therefore, this dissertation will first quantify attention deficits post-stroke before investigating whether preserved cognitive abilities, including attention, can improve auditory sentence comprehension post-stroke. In Experiment 1a, three components of attention (alerting, orienting, executive control) were measured in persons with aphasia and matched-controls using visual and auditory versions of the well-studied Attention Network Test. Experiment 1b then explored the neural resources supporting each component of attention in the visual and auditory modalities in chronic stroke participants. The results from Experiment 1a indicate that alerting, orienting, and executive control are uniquely affected by presentation modality. The lesion-symptom mapping results from Experiment 1b associated the left angular gyrus with visual executive control, the left supramarginal gyrus with auditory alerting, and Broca’s area (pars opercularis) with auditory orienting attention post-stroke. Overall, these findings indicate that perceptual modality may impact the lateralization of some aspects of attention, thus auditory attention may be more susceptible to impairment after a left hemisphere stroke.

Prosody, rhythm and pitch changes associated with spoken language may improve spoken language comprehension in persons with aphasia by recruiting intact cognitive abilities (e.g., attention and working memory) and their associated non-lesioned brain regions post-stroke. Therefore, Experiment 2 explored the relationship between cognition, two unique prosody manipulations, lesion location, and auditory sentence comprehension in persons with chronic stroke and matched-controls. The combined results from Experiment 2a and 2b indicate that stroke participants with better auditory orienting attention and a specific left fronto-parietal network intact had greater comprehension of sentences spoken with sentence prosody. For list prosody, participants with deficits in auditory executive control and/or short-term memory and the left angular gyrus and globus pallidus relatively intact, demonstrated better comprehension of sentences spoken with list prosody. Overall, the results from Experiment 2 indicate that following a left hemisphere stroke, individuals need good auditory attention and an intact left fronto-parietal network to benefit from typical sentence prosody, yet when cognitive deficits are present and this fronto-parietal network is damaged, list prosody may be more beneficial.

Previous research has determined that sentence comprehension is affected when taxing an individual’s cognitive resources, such as attentional control and working memory. This can be done by manipulating the prosody of simple and complex sentences, by allowing irregular rhythm and pitch changes to occur within speech. In the present thesis, neurotypical adults were asked to comprehend sentences with normal and monotone prosody in three different versions of a sentence-picture matching task. A no-load version served as a control with the other two taxing cognitive resources in these individuals. In addition, individuals completed four other tasks that are known to reliably measure working memory. Our results indicate a possible relationship between high accuracy in complex sentences spoken in a monotone prosody with working memory when time restraints are placed on individuals. Collectively, these results may lead to a new way of working with individuals in speech therapy who have suffered a stroke by better understanding the cognitive resources that are taxed in different types of sentence comprehension settings.

Previous research from Rajsic et al. (2015, 2017) suggests that a visual form of confirmation bias arises during visual search for simple stimuli, under certain conditions, wherein people are biased to seek stimuli matching an initial cue color even when this strategy is not optimal. Furthermore, recent research from our lab suggests that varying the prevalence of cue-colored targets does not attenuate the visual confirmation bias, although people still fail to detect rare targets regardless of whether they match the initial cue (Walenchok et al. under review). The present investigation examines the boundary conditions of the visual confirmation bias under conditions of equal, low, and high cued-target frequency. Across experiments, I found that: (1) People are strongly susceptible to the low-prevalence effect, often failing to detect rare targets regardless of whether they match the cue (Wolfe et al., 2005). (2) However, they are still biased to seek cue-colored stimuli, even when such targets are rare. (3) Regardless of target prevalence, people employ strategies when search is made sufficiently burdensome with distributed items and large search sets. These results further support previous findings that the low-prevalence effect arises from a failure to perceive rare items (Hout et al., 2015), while visual confirmation bias is a bias of attentional guidance (Rajsic et al., 2015, 2017).

ABSTRACT

Malawi, as a low and middle income country (LMIC), with one of the lowest per capita gross domestic products, faces challenges in the provision of healthcare to its citizens. According to the Centers for Disease Control (CDC), leading causes of death include but are not limited to, lower respiratory disease, stroke, cancer, neonatal disorders, and nutritional deficiencies. Feeding and swallowing disorders can present as a symptom to any of these medical diagnoses. Currently, there are no known studies focusing on the service provision for feeding and swallowing disorders in Malawi.

This pilot study was designed to provide a baseline on how feeding and swallowing disorders are currently being provided for in an emerging country like Malawi. Malawian healthcare professionals who see patients with feeding and swallowing disorders completed a survey and interview pertaining to their personal demographics, caseload, opinions, experiences, and treatment recommendations regarding the management of swallowing disorders (dysphagia).

Results indicate a wide range of occupations (Otolaryngoloists, Rehabilitation Technicians, Audiology Technicians, and Nurses) are involved in feeding and swallowing care. Participants expressed a high obligation to provide services for feeding and swallowing disorders, as well as a high concern for their patients. Generally, participants expressed high confidence in their treatment abilities, which did not correspond to knowledge of treatment recommendations that meet U.S. standards of care. Specifically, there was no variation in treatment recommendations across severities and a general lack of resources and tools for assessing and treating dysphagia. Treatment recommendations tended to align with resources currently available in Malawi.

Implications for the utilization of NGOs (non-governmental organizations) and the education of healthcare providers on feeding and swallowing disorders in the social and cultural contexts of this country are discussed.

Latino parents of children with feeding disorders completed a survey about their experiences accessing support and the cultural competence of their providers. This work is a follow-up project to a presented American Speech and Hearing Association Conference poster (Stats-Caldwell, Lindsay, Van Vuren, 2017). That project revealed caregivers’ use of social media and indicated an overall perceived lack of support from providers. In the present survey, Latino caregivers identified the resources they consult and rated the level of helpfulness in addition to the types of supports they sought and received from these resources. Results indicate a considerable reliance on pediatricians in both frequency of consultation and helpfulness ratings. No significant difference was seen between the frequency of consultation between pediatricians, speech-language pathologists and other service providers. No significant difference was found in the helpfulness ratings between speech-language pathologists and topic-specific social media pages, nor speech-language pathologists and grandmothers. Participants indicated reliance on social media for informational resources. The influence of social media is discussed. The cultural implications of treating this population are also reviewed.

Objective
The objective of this study is to compare amyloid β (Aβ) PET positive and negative patients to their neuropsychological profiles. There is a definitive link between Aβ deposits and cognitive disorders such as MCI or Alzheimer’s disease (AD), but does its presence justify the costly imaging tests based on its clinical context?
Background
Amnestic MCI is largely considered prodromal to AD/dementia in a high majority of cases. [1] Many studies have shown a positive correlation between Aβ PET positive individuals and their likelihood to progress to AD. Aβ deposits in the brain are not always a sign of AD or even MCI, and many elderly people live normal lives with elevated levels. The presence of Aβ in the brain should be carefully considered alongside other tests before making a clinical diagnosis of MCI or AD.
Methods
130 subjects from Barrow Neurological Institute (Phoenix, AZ) were included in this study. Amyloid PET report data was pulled from Dignity Health St. Joseph’s Hospital and Medical Center Outpatient Imaging. Amyloid PET scans obtained by using F-18 florbetapir compound and reviewed by an expert radiologist providing a qualitative status of amyloid-beta positive (+) or negative (-). All data was anonymized and categorized into positive amyloid PET, negative amyloid PET, and clinical diagnosis based on neuropsychological profiles.
Results
The demographic data indicated that 38.5% of the 91 patients diagnosed as amnestic MCI were amyloid PET negative while 61.5% were amyloid PET positive. Of the 39 patients diagnosed as Dementia or AD 15.4% were amyloid PET negative and 84.6% were amyloid PET positive. Correlational analysis between diagnosis and neuropsychological variables suggests that some variables correlate well while others do not. There is a significant correlation between diagnosis and dementia rating scale (DRS) r(24) = -.762, between diagnosis and TrailsB Test r(39) = .397, between diagnosis and phonetic fluency r(30) = -.383, between diagnosis and semantic fluency r(29) = -.369, and between diagnosis and the Boston Naming Test (BNT) r(36) = -.312. Comparing the PET positive and PET negative groups there is a marginal significance in the Boston Naming Test (T=1.945, P=.060) suggesting PET positive individuals test lower than PET negative.
Conclusion
Based on all the results of this study, amyloid PET is still a clinical indicator that an individual might be MCI or dementia/AD, but it has its exceptions. A small number of patients diagnosed as dementia/AD had a negative amyloid PET suggesting that beta amyloid plaques are not the only cause of the disease. There is a strong suggestion that amyloid plaques are a major factor in the progression of dementia or AD, however the results from an amyloid PET cannot be directly related to a diagnosis.

Working memory and cognitive functions contribute to speech recognition in normal hearing and hearing impaired listeners. In this study, auditory and cognitive functions are measured in young adult normal hearing, elderly normal hearing, and elderly cochlear implant subjects. The effects of age and hearing on the different measures are investigated. The correlations between auditory/cognitive functions and speech/music recognition are examined. The results may demonstrate which factors can better explain the variable performance across elderly cochlear implant users.