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Investigating the influence of top-down mechanisms on hemispheric asymmetries in verbal memory

Description

It is commonly known that the left hemisphere of the brain is more efficient in the processing of verbal information, compared to the right hemisphere. One proposal suggests that hemispheric asymmetries in verbal processing are due in part to the efficient use of top-down mechanisms by the left hemisphere. Most…

It is commonly known that the left hemisphere of the brain is more efficient in the processing of verbal information, compared to the right hemisphere. One proposal suggests that hemispheric asymmetries in verbal processing are due in part to the efficient use of top-down mechanisms by the left hemisphere. Most evidence for this comes from hemispheric semantic priming, though fewer studies have investigated verbal memory in the cerebral hemispheres. The goal of the current investigations is to examine how top-down mechanisms influence hemispheric asymmetries in verbal memory, and determine the specific nature of hypothesized top-down mechanisms. Five experiments were conducted to explore the influence of top-down mechanisms on hemispheric asymmetries in verbal memory. Experiments 1 and 2 used item-method directed forgetting to examine maintenance and inhibition mechanisms. In Experiment 1, participants were cued to remember or forget certain words, and cues were presented simultaneously or after the presentation of target words. In Experiment 2, participants were cued again to remember or forget words, but each word was repeated once or four times. Experiments 3 and 4 examined the influence of cognitive load on hemispheric asymmetries in true and false memory. In Experiment 3, cognitive load was imposed during memory encoding, while in Experiment 4, cognitive load was imposed during memory retrieval. Finally, Experiment 5 investigated the association between controlled processing in hemispheric semantic priming, and top-down mechanisms used for hemispheric verbal memory. Across all experiments, divided visual field presentation was used to probe verbal memory in the cerebral hemispheres. Results from all experiments revealed several important findings. First, top-down mechanisms used by the LH primarily used to facilitate verbal processing, but also operate in a domain general manner in the face of increasing processing demands. Second, evidence indicates that the RH uses top-down mechanisms minimally, and processes verbal information in a more bottom-up manner. These data help clarify the nature of top-down mechanisms used in hemispheric memory and language processing, and build upon current theories that attempt to explain hemispheric asymmetries in language processing.

ContributorsTat, Michael J (Author) / Azuma, Tamiko (Thesis advisor) / Goldinger, Stephen D (Committee member) / Liss, Julie M (Committee member) / Arizona State University (Publisher)

Created2013

Grounding concepts: physical interaction can provide minor benefit to category learning

Description

Categories are often defined by rules regarding their features. These rules may be intensely complex yet, despite the complexity of these rules, we are often able to learn them with sufficient practice. A possible explanation for how we arrive at consistent category judgments despite these difficulties would be that we…

Categories are often defined by rules regarding their features. These rules may be intensely complex yet, despite the complexity of these rules, we are often able to learn them with sufficient practice. A possible explanation for how we arrive at consistent category judgments despite these difficulties would be that we may define these complex categories such as chairs, tables, or stairs by understanding the simpler rules defined by potential interactions with these objects. This concept, called grounding, allows for the learning and transfer of complex categorization rules if said rules are capable of being expressed in a more simple fashion by virtue of meaningful physical interactions. The present experiment tested this hypothesis by having participants engage in either a Rule Based (RB) or Information Integration (II) categorization task with instructions to engage with the stimuli in either a non-interactive or interactive fashion. If participants were capable of grounding the categories, which were defined in the II task with a complex visual rule, to a simpler interactive rule, then participants with interactive instructions should outperform participants with non-interactive instructions. Results indicated that physical interaction with stimuli had a marginally beneficial effect on category learning, but this effect seemed most prevalent in participants were engaged in an II task.

ContributorsCrawford, Thomas (Author) / Homa, Donald (Thesis advisor) / Glenberg, Arthur (Committee member) / McBeath, Michael (Committee member) / Brewer, Gene (Committee member) / Arizona State University (Publisher)

Created2014

Service-related conditions and higher-order cognitive processing in military veteran college students

Description

Military veterans have a significantly higher incidence of mild traumatic brain injury (mTBI), depression, and Post-traumatic stress disorder (PTSD) compared to civilians. Military veterans also represent a rapidly growing subgroup of college students, due in part to the robust and financially incentivizing educational benefits under the Post-9/11 GI Bill. The…

Military veterans have a significantly higher incidence of mild traumatic brain injury (mTBI), depression, and Post-traumatic stress disorder (PTSD) compared to civilians. Military veterans also represent a rapidly growing subgroup of college students, due in part to the robust and financially incentivizing educational benefits under the Post-9/11 GI Bill. The overlapping cognitively impacting symptoms of service-related conditions combined with the underreporting of mTBI and psychiatric-related conditions, make accurate assessment of cognitive performance in military veterans challenging. Recent research findings provide conflicting information on cognitive performance patterns in military veterans. The purpose of this study was to determine whether service-related conditions and self-assessments predict performance on complex working memory and executive function tasks for military veteran college students. Sixty-one military veteran college students attending classes at Arizona State University campuses completed clinical neuropsychological tasks and experimental working memory and executive function tasks. The results revealed that a history of mTBI significantly predicted poorer performance in the areas of verbal working memory and decision-making. Depression significantly predicted poorer performance in executive function related to serial updating. In contrast, the commonly used clinical neuropsychological tasks were not sensitive service-related conditions including mTBI, PTSD, and depression. The differing performance patterns observed between the clinical tasks and the more complex experimental tasks support that researchers and clinicians should use tests that sufficiently tax verbal working memory and executive function when evaluating the subtle, higher-order cognitive deficits associated with mTBI and depression.

ContributorsGallagher, Karen Louise (Author) / Azuma, Tamiko (Thesis advisor) / Liss, Julie (Committee member) / Lavoie, Michael (Committee member) / Arizona State University (Publisher)

Created2017

Optimizing Biofeedback and Learning in an EEG-Based Brain-Computer Interface

Description

Brain-computer interface technology establishes communication between the brain and a computer, allowing users to control devices, machines, or virtual objects using their thoughts. This study investigates optimal conditions to facilitate learning to operate this interface. It compares two biofeedback methods, which dictate the relationship between brain activity and the movement…

Brain-computer interface technology establishes communication between the brain and a computer, allowing users to control devices, machines, or virtual objects using their thoughts. This study investigates optimal conditions to facilitate learning to operate this interface. It compares two biofeedback methods, which dictate the relationship between brain activity and the movement of a virtual ball in a target-hitting task. Preliminary results indicate that a method in which the position of the virtual object directly relates to the amplitude of brain signals is most conducive to success. In addition, this research explores learning in the context of neural signals during training with a BCI task. Specifically, it investigates whether subjects can adapt to parameters of the interface without guidance. This experiment prompts subjects to modulate brain signals spectrally, spatially, and temporally, as well differentially to discriminate between two different targets. However, subjects are not given knowledge regarding these desired changes, nor are they given instruction on how to move the virtual ball. Preliminary analysis of signal trends suggests that some successful participants are able to adapt brain wave activity in certain pre-specified locations and frequency bands over time in order to achieve control. Future studies will further explore these phenomena, and future BCI projects will be advised by these methods, which will give insight into the creation of more intuitive and reliable BCI technology.

ContributorsLancaster, Jenessa Mae (Co-author) / Appavu, Brian (Co-author) / Wahnoun, Remy (Co-author, Committee member) / Helms Tillery, Stephen (Thesis director) / Barrett, The Honors College (Contributor) / Harrington Bioengineering Program (Contributor) / Department of Psychology (Contributor)

Created2014-05

The Impact of Blocked vs. Distributed Category Learning on Subsequent Generalization

Description

It is a well-established finding in memory research that spacing or distributing information, as opposed to blocking all the information together, results in an enhanced memory of the learned material. Recently, researchers have decided to investigate if this spacing effect is also beneficial in category learning. In a set of…

It is a well-established finding in memory research that spacing or distributing information, as opposed to blocking all the information together, results in an enhanced memory of the learned material. Recently, researchers have decided to investigate if this spacing effect is also beneficial in category learning. In a set of experiments, Carvalho & Goldstone (2013), demonstrated that a blocked presentation showed an advantage during learning, but that ultimately, the distributed presentation yielded better performance during a post-learning transfer test. However, we have identified a major methodological issue in this study that we believe contaminates the results in a way that leads to an inflation and misrepresentation of learning levels. The present study aimed to correct this issue and re-examine whether a blocked or distributed presentation enhances the learning and subsequent generalization of categories. We also introduced two shaping variables, category size and distortion level at transfer, in addition to the mode of presentation (blocked versus distributed). Results showed no significant differences of mode of presentation at either the learning or transfer phases, thus supporting our concern about the previous study. Additional findings showed benefits in learning categories with a greater category size, as well as higher classification accuracy of novel stimuli at lower-distortion levels.

ContributorsJacoby, Victoria Leigh (Author) / Homa, Donald (Thesis director) / Brewer, Gene (Committee member) / Davis, Mary (Committee member) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)

Created2017-12

REFLEX: Relative Executive Function Level Examination

Description

The goal of this thesis project was to develop a digital, quantitative assessment of executive functioning skills and problem solving abilities. This assessment was intended to serve as a relative measure of executive functions and problem solving abilities rather than a diagnosis; the main purpose was to identify areas for…

The goal of this thesis project was to develop a digital, quantitative assessment of executive functioning skills and problem solving abilities. This assessment was intended to serve as a relative measure of executive functions and problem solving abilities rather than a diagnosis; the main purpose was to identify areas for improvement and provide individuals with an understanding of their current ability levels. To achieve this goal, we developed a web-based assessment through Unity that used gamelike modifications of Flanker, Antisaccade, Embedded Images, Raven’s Matrices, and Color / Order Memory tasks. Participants were invited to access the assessment at www.ExecutiveFunctionLevel.com to complete the assessment and their results were analyzed. The findings of this project indicate that these tasks accurately represent executive functioning skills, the Flanker Effect is present in the collected data, and there is a notable correlation between each of the REFLEX challenges. In conclusion, we successfully developed a short, gamelike, online assessment of executive functioning and problem solving abilities. Future developments of REFLEX could look into immediate scoring, developing a mobile application, and externally validating the results.

ContributorsAnderson, Gabriel (Co-author) / Anderson, Mikayla (Co-author) / Brewer, Gene (Thesis director) / Kobayashi, Yoshihiro (Committee member) / Johnson, Mina (Committee member) / Computer Science and Engineering Program (Contributor) / Barrett, The Honors College (Contributor)

Created2021-05

REFLEX: Relative Executive Function Level Examination

Description

The goal of this thesis project was to develop a digital, quantitative assessment of executive functioning skills and problem solving abilities. This assessment was intended to serve as a relative measure of executive functions and problem solving abilities rather than a diagnosis; the main purpose was to identify areas for…

The goal of this thesis project was to develop a digital, quantitative assessment of executive functioning skills and problem solving abilities. This assessment was intended to serve as a relative measure of executive functions and problem solving abilities rather than a diagnosis; the main purpose was to identify areas for improvement and provide individuals with an understanding of their current ability levels. To achieve this goal, we developed a web-based assessment through Unity that used gamelike modifications of Flanker, Antisaccade, Embedded Images, Raven’s Matrices, and Color / Order Memory tasks. Participants were invited to access the assessment at www.ExecutiveFunctionLevel.com to complete the assessment and their results were analyzed. The findings of this project indicate that these tasks accurately represent executive functioning skills, the Flanker Effect is present in the collected data, and there is a notable correlation between each of the REFLEX challenges. In conclusion, we successfully developed a short, gamelike, online assessment of executive functioning and problem solving abilities. Future developments of REFLEX could look into immediate scoring, developing a mobile application, and externally validating the results.

ContributorsAnderson, Mikayla (Co-author) / Anderson, Gabriel (Co-author) / Brewer, Gene (Thesis director) / Kobayashi, Yoshihiro (Committee member) / Johnson, Mina (Committee member) / Department of Finance (Contributor) / Barrett, The Honors College (Contributor)

Created2021-05

The Effect of Curiosity Type on the Delay of Feedback Benefit

Description

After answering a test question, feedback of the correct answer provided after a brief delay can be more beneficial to learning than feedback provided immediately (Brackbill & Kappy, 1962; Kulhavy & Anderson, 1972). Several theoretical models have been proposed to explain this delay-of-feedback benefit, with the most well supported being…

After answering a test question, feedback of the correct answer provided after a brief delay can be more beneficial to learning than feedback provided immediately (Brackbill & Kappy, 1962; Kulhavy & Anderson, 1972). Several theoretical models have been proposed to explain this delay-of-feedback benefit, with the most well supported being that delaying feedback promotes anticipation of the correct answer, which has been examined using curiosity as a measure of answer anticipation (Mullaney et al. 2014). The present study tested this model across two task designs, one designed to elicit epistemic curiosity, and one designed to elicit perceptual curiosity, to determine if the relationship between curiosity and feedback delay is type-dependent. In Task 1, participants answered trivia questions, reported their subjective level of curiosity to know the answer, and then received correct answer feedback after a variable delay (0s, 4s, or 8s). Task 2 was identical to Task 1, except that participants learned and were tested on the identities of blurred pictures, rather than trivia question answers. A subsequent learning retention test demonstrated a significant effect of curiosity, but not feedback delay, on performance in the trivia task, and no significant effect of curiosity, but a negative effect of feedback delay, on performance in the blurred pictures task. Neither task found a significant interaction effect between curiosity and delay group, which fails to support the answer anticipation model of the delay-of-feedback benefit.

ContributorsMcDaniel, Layla (Author) / Brewer, Gene (Thesis director) / Pages, Erika (Committee member) / Barrett, The Honors College (Contributor) / Department of Psychology (Contributor)

Created2023-05

Executive function and language control in bilinguals with a history of mild traumatic brain injury

Description

Adults with a history of traumatic brain injury (TBI) often show deficits in executive functioning, which include the ability to inhibit, switch, and attend to task relevant information. These abilities are also essential for language processing in bilinguals, who constantly inhibit and switch between languages. Currently, there is no data…

Adults with a history of traumatic brain injury (TBI) often show deficits in executive functioning, which include the ability to inhibit, switch, and attend to task relevant information. These abilities are also essential for language processing in bilinguals, who constantly inhibit and switch between languages. Currently, there is no data regarding the effect of TBI on executive function and language processing in bilinguals. This study used behavioral and eye-tracking measures to examine the effect of mild traumatic brain injury (mTBI) on executive function and language processing in Spanish-English bilinguals. In Experiment 1, thirty-nine healthy bilinguals completed a variety of executive function and language processing tasks. The primary executive function and language processing tasks were paired with a cognitive load task intended to simulate mTBI. In Experiment 2, twenty-two bilinguals with a history of mTBI and twenty healthy control bilinguals completed the same executive function measures and language processing tasks. The results revealed that bilinguals with a history of mTBI show deficits in specific executive functions and have higher rates of language processing deficits than healthy control bilinguals. Additionally, behavioral and eye-tracking data suggest that these language processing deficits are related to underlying executive function abilities. This study also identified a subset of bilinguals who may be at the greater risk of language processing deficits following mTBI. The findings of this study have a direct impact on the identification of executive function deficits and language processing deficits in bilinguals with a history mTBI.

ContributorsRatiu, Ileana (Author) / Azuma, Tamiko (Thesis advisor) / Goldinger, Stephen D (Committee member) / Liss, Julie M (Committee member) / Arizona State University (Publisher)

Created2015

Experimental Manipulation of Motivation and Self-Efficacy for Self-Control

Description

Self-control has been shown to be an important influence behind a variety of risk and protective behaviors, such as substance abuse. Although prior research points to the existence of multiple dimensions of self-control, this concept is not consistently defined and frequently only studied as a conglomerate in clinical research. The…

Self-control has been shown to be an important influence behind a variety of risk and protective behaviors, such as substance abuse. Although prior research points to the existence of multiple dimensions of self-control, this concept is not consistently defined and frequently only studied as a conglomerate in clinical research. The current study sought to examine how two experimental manipulations of subcomponents of self-control (motivation and self-efficacy) affect real-world consumptive behavior after accounting for executive function. Additionally, the validity and reliability of a brief state survey measure of perceived self-control capacity, internal motivation, and external motivation was tested. The goal was to examine how basic scientific principles involved in self-control translate into clinically relevant behaviors, which may inform understanding of momentary lapses in self-control behavior, potentially leading to novel prevention and intervention efforts. 94 college students completed a 1-2 hour laboratory protocol during which they completed survey and laboratory-based tasks of self-control and related behaviors, executive function, and ad libitum alcohol consumption. Results showed that the self-efficacy manipulation successfully increased perceived self-control capacity, although this did not lead to a significant reduction in consumption. The motivation manipulation neither increased motivation nor reduced consumption in this sample. However, the brief state survey measure of self-control subcomponents demonstrated strong test-retest reliability and distinction from trait self-control, demonstrating its viability for use in future research. By elucidating the relationships between specific mechanisms of self-control, laboratory-based tasks and manipulations, and real-world consumptive behaviors, prevention and intervention efforts for problems such as alcohol abuse may be tailored to the needs of the individual and made more impactful and cost-effective.

ContributorsPapova, Anna (Author) / Corbin, William R. (Thesis advisor) / Brewer, Gene (Committee member) / Karoly, Paul (Committee member) / McClure, Samuel (Committee member) / Arizona State University (Publisher)

Created2020

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