Psychology Commons^™

The Impact Of Alzheimer Disease On Semantic Knowledge, Maileen G. Ulep

UNLV Theses, Dissertations, Professional Papers, and Capstones

The research furthers the understanding of the impact of Alzheimer disease (AD) on cognition and the organization of semantic knowledge in the brain, which might contribute to the development of diagnostic and staging tools, and interventions to palliate cognitive deficits. The disruption of semantic knowledge in AD is well documented in the literature. Much of the existing research focuses on the general impact AD has on semantic knowledge. This study explores the impact of AD on specific domains of knowledge, chiefly, living kinds and artifacts, critical to ordinary functioning. The content, organization and structure of the investigated domains of knowledge …

Modeling Semantic Structure And Spreading Activation In Retrieval Tasks, Abhilasha Ashok Kumar

Arts & Sciences Electronic Theses and Dissertations

Considerable work in the past decade has focused on representational accounts of how semantic information is acquired and organized, leading to the advent of modern Distributional Semantic Models (DSMs) that learn word meanings by extracting statistical information from large text corpora. However, mechanistic accounts for how meaning-related information is accessed and retrieved from semantic representations to ultimately produce responses within semantic tasks remain relatively understudied, especially for production-based tasks that require the selection of a single response amongst several activated competitors, such as in free association and sentence completion tasks. This dissertation evaluated the extent to which state-of-the-art DSMs combined …

Lexical Retrieval Inhibition From Semantically Related Retrieval Primes, Abhilasha Ashok Kumar

Arts & Sciences Electronic Theses and Dissertations

The phenomenological experience of lexical retrieval involves conscious and active attempts to retrieve semantically related information, but the direct influence of this retrieval process on subsequent retrieval is presently unknown. We investigated the influence of passively viewing or actively retrieving different types of information at the critical moment preceding lexical retrieval through a novel priming paradigm. Participants attempted to retrieve target words (e.g., FOLIAGE) from their low-frequency definitions or descriptions (e.g., the leafy parts of a plant or tree, collectively). Across five experiments, target retrieval was preceded by the brief presentation of a prime word (Experiment 1), progressive demasking of …

The Famous Names Discrimination Task As A Biomarker Of Alzheimer's Disease Risk: An Erp Study, Elizabeth Rose Paitel

Master's Theses (2009 -)

Current ERP research emphasizes age- and pathology-related declines in neural processing in the form of attenuated amplitudes and prolonged latencies. Notably, there is a gap in the ERP literature regarding neural processing trajectories in the time between healthy young adulthood and clinical MCI/AD samples. fMRI research, however, has demonstrated periods of increased, compensatory activation in healthy, cognitively intact APOE ɛ4 carriers both during resting state and event-related tasks (Bondi, Houston, Eyler, & Brown, 2005; Evans et al., 2014; Filippini et al., 2009; Rao et al., 2015), consistent with compensatory theories of cognitive aging (Cabeza, 2002; Park & Reuter-Lorenz, 2009; Reuter-Lorenz …

Toddlers Activate Lexical Semantic Knowledge In The Absence Of Visual Referents: Evidence From Auditory Priming, Jon A. Willits, Erica H. Wojcik, Mark S. Seidenberg, Jenny R. Saffran

Erica Wojcik

Language learners rapidly acquire extensive semantic knowledge, but the development of this knowledge is difficult to study, in part because it is difficult to assess young children's lexical semantic representations. In our studies, we solved this problem by investigating lexical semantic knowledge in 24-month-olds using the Head-turn Preference Procedure. In Experiment 1, looking times to a repeating spoken word stimulus (e.g., kitty-kitty-kitty) were shorter for trials preceded by a semantically related word (e.g., dog-dog-dog) than trials preceded by an unrelated word (e.g., juice-juice-juice). Experiment 2 yielded similar results using a method in which pairs of words were presented on the …

The Semantic Memory Imaging In Late Life Pilot Study, Michael Adam Sugarman

Wayne State University Dissertations

Introduction: Several functional magnetic resonance imaging (fMRI) studies have analyzed the famous name discrimination task (FNDT), an uncontrolled semantic memory probe requiring discrimination between famous and unfamiliar individuals. Completion of this simple task recruits a semantic memory network that has shown utility in determining risk for Alzheimer's disease (AD). Specific semantic memory probes using biographical information associated with famous individuals may build on previous findings and yield superior information regarding risk for AD.

Method: Sixteen cognitively intact elders completed the FNDT and two novel tasks during fMRI: Categories (matching famous individuals to occupational categories) and Attributes (matching famous individuals to …

Toddlers Activate Lexical Semantic Knowledge In The Absence Of Visual Referents: Evidence From Auditory Priming, Jon A. Willits, Erica H. Wojcik, Mark S. Seidenberg, Jenny R. Saffran

Psychology

Language learners rapidly acquire extensive semantic knowledge, but the development of this knowledge is difficult to study, in part because it is difficult to assess young children's lexical semantic representations. In our studies, we solved this problem by investigating lexical semantic knowledge in 24-month-olds using the Head-turn Preference Procedure. In Experiment 1, looking times to a repeating spoken word stimulus (e.g., kitty-kitty-kitty) were shorter for trials preceded by a semantically related word (e.g., dog-dog-dog) than trials preceded by an unrelated word (e.g., juice-juice-juice). Experiment 2 yielded similar results using a method in which pairs of words were presented on the …

Contributions Of Signal-Detection Mechanisms And Semantic Memory Representations To Famous Name Recognition, Ben P. Bowles

Electronic Thesis and Dissertation Repository

In past research, investigators have often used the recognition memory paradigm to study the cognitive and neural processes that permit the ability to accurately assess whether or not stimuli are familiar. This paradigm involves presenting stimuli to participants in a study phase, and examining their later recognition of them when these stimuli are subsequently presented again in a later test phase. It is not well understood, however, whether the same mechanisms that support familiarity assessment in recognition memory also support familiarity based on general life experience (e.g., recognizing a famous celebrity in daily life). To address this, I implemented modified …