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Relationship Between Cognitive Performance, Physical Activity, And Socio-Demographic/ Individual Characteristics Among Aging Americans, Imtiaz Masfique Dowllah

Theses and Dissertations

Despite the attenuation of association following adjustments for covariates, participants who engaged in 3–6 hr/wk of vigorous- and > 1 hr/wk of moderate-intensity PA scored significantly higher in tests that assessed executive function and processing speed domains of cognition compared to inactive peers (η2 = 0.005 & 0.007 respectively, p < 0.05). Also, after adjustment, the effects of 1–3 hr/wk of vigorous-intensity PA became trivial for the delayed recall memory domain test scores (β = 0.33; 95% CI: –0.01, 0.67; η2 = 0.002; p = 0.56). There was no clear dose-response relationship between the cognitive test scores and weekly moderate-intensity PA. Interestingly, higher handgrip strength and higher late-life body-mass-index were associated with a higher performance across all cognitive domains. Observed associations provide evidence linking habitual PA with superior cognition health among older adults. Furthermore, increased muscle strength and higher late-life adiposity may …

Age Related Decline In Memory: Examining The Mediation Effect Of Processing, Executive Functioning And Intelligence In Normal Adults, Jada J. Stewart

Theses and Dissertations

Multiple mediation analyses that collectively examine the prominent theories of cognitive aging (i.e., Common Cause, Processing, and Executive Decline Hypotheses) along with other cognitive domains that are sensitive to aging are rare. Moreover, having identified that cognition begins to decline as early as 30 years old, few studies have examined the mechanisms that underlie memory change among younger aging individuals. As a result, it is unclear whether relevant mediating variables have been excluded from early research on age-related memory decline, or to what extent rehabilitative strategies are applicable as early interventions for maintaining cognitive functioning into late life.

The present …

Memory Retrieval Is Maintained By Intrinsic And Synaptic Plasticity In Prelimbic Cortex, James Otis

Theses and Dissertations

Abnormally strong memories underlie common disorders including addiction and post-traumatic stress disorder (PTSD). Memory disruption would therefore be beneficial for treatment of these disorders. Evidence reveals that cocaine conditioned place preference (CPP) memories are susceptible to long-lasting disruption during memory retrieval. For example, inhibition of β-adrenergic receptor (β-AR) activity within the prelimbic medial prefrontal cortex (PL-mPFC) prevents cocaine CPP memory retrieval, and this retrieval impairment is both long-lasting and prevents subsequent reinstatement of the CPP. Despite this, whether PL-mPFC β-AR activity is a fundamental mechanism required to maintain retrieval of other memories is unclear. Furthermore, how PL-mPFC β-AR activity maintains …

Effect Of Repeated Dosing Of Delta 9-Tetrahydrocannabinol, The Major Psychoactive Ingredient Of Marijuana, On Memory In Mice, Floride Niyuhire

Theses and Dissertations

Purpose: Marijuana is the most widely used illicit drug in the United States. However, marijuana and cannabinoid derivatives have potential therapeutic uses. Studies in cannabis users have yielded contradictory results with regard to long-term effects on cognitive functions. There is no prospective study assessing this issue, and such studies may raise ethical issues in humans, whereas mice have been shown to exhibit similar cannabinoid-mediated behaviors as humans. The purpose of this study was to assess the consequences of chronic administration of Δ9-THC, the major psychoactive component of marijuana, in a mouse memory model. Methods: In Experiment 1, the dose-response relationship …

Processing Strategies And Recall Performance For Narrative Passages And Word Lists Of Negative And Neutral Affective Valence In Depression, Lora L. Sloan

Theses and Dissertations

Depressed individuals have been found to exhibit memory deficits on tasks that require effortful processing. They have also been found to remember negative materials better than their nondepressed cohorts. While these findings are well-documented, there have been few studies designed to examine how and why these differences in recall occur. The present study examined prose passage and word list recall in depressed and nondepressed college students. Processing times and structure of recall were also examined to assist in determining how material was processed and remembered. Half of the passages and word lists utilized were of negative affective valence and half …