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Differential Time Frequency Dynamics in Memory and Prioritization of Value-Directed Stimuli

Description
The ability to preferentially encode and later retrieve valuable information amidst a plethora of miscellaneous information is an essential aspect of human memory. Several hypotheses have been suggested to explain the enhanced ability to successfully encode high value items. These include the hypothesis that the prefrontal executive control processes are…

The ability to preferentially encode and later retrieve valuable information amidst a plethora of miscellaneous information is an essential aspect of human memory. Several hypotheses have been suggested to explain the enhanced ability to successfully encode high value items. These include the hypothesis that the prefrontal executive control processes are engaged for valuable information, producing elaborative rehearsal strategy. Another hypothesis is that greater attentional resources are allocated to higher value items via the reward driven mid-brain dopamine systems interacting with hippocampal and cortical areas to produce enhanced memory. To further understand the neural mechanisms of value on memory, electroencephalogram data under a value-directed remembering paradigm (VDR) was analyzed for oscillatory activity. During the task, participants encoded words assigned a different point value with the instruction to maximize the point value of recognized words during test. To analyze frequency activity during encoding, conditions of subsequent memory as subjective responses of either recollection (i.e., “remember”) and familiarity (i.e., “know”) were assessed. A possible way to observe the allocation of attention resources in the brain are alpha oscillations (8-15 Hz) which are thought to underlie this process. Participants demonstrated superior memory for high versus low value point items. Following the hypothesis that there is a greater recruitment of attentional resources for high value information, alpha oscillatory power in the occipital/temporal cortex displayed significantly more desynchronization for high value compared to low value conditions during encoding. As well, successful retrieval compared with unsuccessful retrieval and subsequent “remember” or “know” conditions resulted in a qualitatively different, more sustained desynchronization of alpha and other unanticipated frequency band oscillations during encoding that are discussed. Taken together, these findings support previous research for alpha-band desynchronization during encoding items of value into memory and potentially open paths to decouple value and memory driven processes.
ContributorsWilliams, Cole (Author) / Brewer, Gene (Thesis advisor) / McClure, Samuel (Committee member) / Blais, Chris (Committee member) / Arizona State University (Publisher)
Created2022
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A Mechanistic Account of the Relation between Working Memory Capacity and Fluid Intelligence

Description
Working memory capacity and fluid intelligence are important predictors of performance in educational settings. Thus, understanding the processes underlying the relation between working memory capacity and fluid intelligence is important. Three large scale individual differences experiments were conducted to determine the mechanisms underlying the relation between working memory capacity and…

Working memory capacity and fluid intelligence are important predictors of performance in educational settings. Thus, understanding the processes underlying the relation between working memory capacity and fluid intelligence is important. Three large scale individual differences experiments were conducted to determine the mechanisms underlying the relation between working memory capacity and fluid intelligence. Experiments 1 and 2 were designed to assess whether individual differences in strategic behavior contribute to the variance shared between working memory capacity and fluid intelligence. In Experiment 3, competing theories for describing the underlying processes (cognitive vs. strategy) were evaluated in a comprehensive examination of potential underlying mechanisms. These data help inform existing theories about the mechanisms underlying the relation between WMC and gF. However, these data also indicate that the current theoretical model of the shared variance between WMC and gF would need to be revised to account for the data in Experiment 3. Possible sources of misfit are considered in the discussion along with a consideration of the theoretical implications of observing those relations in the Experiment 3 data.
ContributorsWingert, Kimberly Marie (Author) / Brewer, Gene A. (Thesis advisor) / McNamara, Danielle (Thesis advisor) / McClure, Samuel (Committee member) / Redick, Thomas (Committee member) / Arizona State University (Publisher)
Created2018