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- All Subjects: hippocampus
- Creators: Ofori, Edward
- Creators: Arnold, Nathaniel
Description
The aim of this study was to examine the effects of Assisted Cycle Therapy (ACT) on self-efficacy and exercise perception in older adults with Down syndrome (DS) after a three times a week for 8 weeks intervention. Thirteen participants were in the ACT group in which a motor assisted their cycling to be performed at least 30% faster than voluntary cycling (VC), 11 participants were in the voluntary cycling group and two participants were in the no cycling (NC) group. The results showed that both exercise groups (i.e., ACT and VC) improved in their self-efficacy after the 8 week intervention. In addition, exercise perception improved following ACT and not VC or NC. Our results are discussed with respect to their future implications for exercise in the DS population. It might be that the yielded results were due to differences in effort required by each intervention group as well as the neurotrophic factors that occur when muscle contractions create synaptic connections resulting in improvement in cognition and feelings of satisfaction. In the future, research should focus on the psychological factors such as social accountability and peer interaction as they relate to ACT and physical activity in person's with DS.
ContributorsTucker, Kori Ann (Author) / Ringenbach, Shannon (Thesis director) / Arnold, Nathaniel (Committee member) / Holzapfel, Simon (Committee member) / School of Nutrition and Health Promotion (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
The aim of this study was to explore cross-sectional and longitudinal aging differences in immediate and delayed visual and verbal memory abilities in individuals with Autism Spectrum Disorder (ASD) compared with neurotypicals (NTs). We measured hippocampal size, fornix fractional anisotropy (FA), and hippocampal and fornix freewater to understand how aging impacts memory structures. Longitudinal findings highlight vulnerabilities in immediate verbal memory and hippocampal volume, while cross-sectional findings indicate fornix freewater may increase at a faster rate in adults with ASD. Future research will examine cognitive and structural sex differences and will study how cognitive measures correlate with structural measures.
ContributorsSullivan, Georgia Rose (Author) / Braden, B. Blair (Thesis director) / Ofori, Edward (Committee member) / Harrington Bioengineering Program (Contributor, Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description
Background: The hippocampus is a critical brain structure for memory formation and other aspects of cognition. The hippocampus and the white matter tracts connecting it to other parts of the brain are known to lose volume and integrity with aging. For populations with prior compromised hippocampal integrity, such as those with autism spectrum disorder (ASD), it is less well known how the hippocampus and its connections will respond to aging. In children with ASD, there may be an initial period of enlarged hippocampi, after which there is a trajectory of faster decline in volume compared to neurotypicals (NT). We have previously identified reduced hippocampal volumes and fornix white matter integrity in middle-age and older adults with ASD compared to matched NT adults. However, freewater (FW) may be a more sensitive structural integrity measure of the hippocampal complex. FW is present in the brain as cerebrospinal fluid but also accumulates within the extracellular spaces indicative of reduced gray matter density and increased axon degeneration. FW shows promise as a more sensitive biomarker for Parkinson’s and Alzheimer’s disease. This study evaluated age-related hippocampal complex FW differences in adults with and without ASD across the adult lifespan. We hypothesized that adults with ASD would demonstrate a larger age association with increasing FW in the hippocampus and fornix, compared to NT adults, and that FW would be a more sensitive brain measure than traditional fractional anisotropy (FA).
Methods: The study consisted of 79 participants with ASD (59 male, 20 female; ages 18-70, mean=40.27 [±17] years) and 77 NT participants (46 male, 31 female; ages 18-71, mean=40.33 [±16] years). Hippocampal and fornix FW and FA values were generated from diffusion tensor images obtained along 32 directions using a b-value of 2500 s/mm2 in the axial direction with 3 mm slice resolution. These images were then processed for eddy current, distortion, b-vec and motion correction, skull stripped, and non-linear registered using Advanced Normalization Tools (ANTs) to the subject’s T1 image. FW and FA maps were calculated using custom written MatLab code and standard atlases containing the hippocampus and fornix were applied.
Results: The right hippocampus showed a significant diagnosis by age interaction (p=0.018), such that the increase in FW with age was greater for adults with ASD. The left hippocampus diagnosis by age interaction approached significance (p=0.055). Similarly, the right fornix showed a significant diagnosis by age interaction (p=0.044), with increases in FW with age as greater for adults with ASD, and the left fornix diagnosis by age interaction approached significance (p=0.053). FA values showed no significant diagnosis by age interactions.
Conclusion: In the hippocampus and fornix, the association between increasing FW and increasing age was more pronounced for adults with ASD than matched NT adults. This may mean that as adults with ASD age, these regions will degenerate faster than their NT peers, which could have implications for accelerated age-related memory decline. However, a notable limitation is the cross-sectional nature of the study. Our ongoing longitudinal study will inform a more definitive picture of brain aging with ASD.
Methods: The study consisted of 79 participants with ASD (59 male, 20 female; ages 18-70, mean=40.27 [±17] years) and 77 NT participants (46 male, 31 female; ages 18-71, mean=40.33 [±16] years). Hippocampal and fornix FW and FA values were generated from diffusion tensor images obtained along 32 directions using a b-value of 2500 s/mm2 in the axial direction with 3 mm slice resolution. These images were then processed for eddy current, distortion, b-vec and motion correction, skull stripped, and non-linear registered using Advanced Normalization Tools (ANTs) to the subject’s T1 image. FW and FA maps were calculated using custom written MatLab code and standard atlases containing the hippocampus and fornix were applied.
Results: The right hippocampus showed a significant diagnosis by age interaction (p=0.018), such that the increase in FW with age was greater for adults with ASD. The left hippocampus diagnosis by age interaction approached significance (p=0.055). Similarly, the right fornix showed a significant diagnosis by age interaction (p=0.044), with increases in FW with age as greater for adults with ASD, and the left fornix diagnosis by age interaction approached significance (p=0.053). FA values showed no significant diagnosis by age interactions.
Conclusion: In the hippocampus and fornix, the association between increasing FW and increasing age was more pronounced for adults with ASD than matched NT adults. This may mean that as adults with ASD age, these regions will degenerate faster than their NT peers, which could have implications for accelerated age-related memory decline. However, a notable limitation is the cross-sectional nature of the study. Our ongoing longitudinal study will inform a more definitive picture of brain aging with ASD.
ContributorsAlvar, Jocelyn R (Author) / Braden, Brittany Blair (Thesis director) / Ofori, Edward (Committee member) / School of Life Sciences (Contributor) / School of International Letters and Cultures (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
This study examines the effectiveness of two modes of exercise on self-efficacy (SE) and exercise perception (EP) in adults with Down syndrome (DS). Thirteen participants attended four sessions: a baseline assessment, an Assisted Cycling Therapy (ACT) session, a resistance training (RT) session, and a session of no training (NT). In the baseline assessment, 1-repetition max (1RM) measurements and voluntary pedal rate measurements were taken. In the cycling intervention, the participant completed 30 minutes of assisted cycling at 35 percent greater than their voluntary pedaling rate. In the resistance training session, 2 sets of 8-12 repetitions of the leg press, chest press, seated row, leg curl, shoulder press, and latissimus pulldown were performed. During the session of no training, participants played board games with student researchers for 35 minutes.Two subsets of the Physical Activity and Self Efficacy Survey were administered prior to each session (i.e., pretest) and after the intervention (i.e., post-test). The results were consistent with the hypothesis that ACT would lead to higher SE than RT or NT. However, ACT did not lead to higher EP than RT or NT as hypothesized. Additionally, it was hypothesized that RT would lead to higher SE and EP than NT, but the results did not support this. In conclusion, an acute session of ACT demonstrated a significant trend for improved self-efficacy in adults with DS.
ContributorsOberbillig, Nicole (Author) / Ringenbach, Shannon (Thesis director) / Ofori, Edward (Committee member) / School of International Letters and Cultures (Contributor) / College of Health Solutions (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05