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Description
The locus coeruleus-norepinephrine system (LC-NE) has been argued to play a vital role in task engagement and attention control by the adaptive gain theory (Aston-Jones & Cohen, 2005). One of the central claims of this theory is that tonic LC activity exhibits a quadratic relationship with task performance. Pupil dynamics have been correlated to LC-NE activity via primate intracranial recordings in ways that provide evidence for the adaptive gain theory. Due to the small size and location of the LC, less is known about LC functioning in humans, leading to a desire to find valid, noninvasive psychophysiological proxies to study this structure. In this paper we performed a replication of Murphy, Robertson, Balsters, & O’Connell (2011) to gather evidence on whether pupil fluctuations and the P3 event-related potential are viable markers for measuring tonic and phasic LC-NE activity in humans. A sample of 33 subjects from the Arizona State University human subjects pool provided usable electroencephalogram and pupillometry data collected during an auditory oddball task. Our analyses largely correspond with those found in Murphy et al. (2011) showing some evidence that pupillometry and P3 can be utilized when studying the LC. Moving forward we will reproduce the full set of analyses from Murphy et al. (2011) with our dataset.
ContributorsStrayer, Deanna L. (Author) / Brewer, Gene (Thesis director) / Robison, Matthew (Committee member) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
Source monitoring refers to the ability to discriminate the origins of memories. The source monitoring framework is a theoretical model that describes the various characteristics of memories and judgement processes necessary for this discrimination process. Little research has analyzed the extent to which predictable encoding contexts influence source monitoring processes. In this study, we found that predictability at encoding aids later source recognition, but only when the test-relevant source dimension was predictable at encoding. The encoding format was either predictable (sequential spatial location) or non-predictable (random spatial location) and the test format was either color or location. In Experiment 1, the encoding format was either predictable or non-predictable spatial locations and participants were tested on the location. In this experiment, predictability did aid when the encoding format matched the test format. The average conditionalized source identification measure was statistically higher for those who saw images appear in a predictable pattern at encoding. In Experiment 2, when participants were tested on an orthogonal source dimension, the average conditionalized source identification measure was not statistically significant for those who saw the images appear in either encoding format. In this experiment, the predictability did not have an effect when the encoding format did not match the test format. In Experiment 3, there was a significant interaction of predictability by source dimension showing an improvement to memory for the predictable source condition and a decrement to memory for the unpredictable source dimension. In this experiment, predictability aided when encoding format matched the test format, but not when the encoding and test format did not match.
ContributorsDickson, Katrina Rebecca (Author) / Brewer, Gene (Thesis director) / Benitez, Viridiana (Committee member) / Ellis, Derek (Committee member) / School of Molecular Sciences (Contributor) / Department of Psychology (Contributor) / College of Health Solutions (Contributor) / Sanford School of Social and Family Dynamics (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Although it has recently been demonstrated that source monitoring (SM) processes may mediate the relationship between working memory (WM) and false memories, little research has investigated whether the quality of monitoring processes can account for this reduction. In the current study, participants performed multiple false memory, WM, and SM tasks. Consistent with previous research, SM abilities mediated the relationship between WM and false memories (regardless of whether or not participants were warned of the illusions at encoding). High SM individuals were better able to recall contextual information from study to correctly reject lures, whereas low SM individuals were more likely to rely on the quality of retrieved details to reject lures. These results suggest that individuals low and high in SM abilities rely on qualitatively different monitoring processes to reduce errors, and that individual differences in diagnostic monitoring strategies may account for previous relationships found between WM and false memories.
ContributorsCoulson, Allison Rose (Author) / Brewer, Gene (Thesis director) / Ellis, Derek (Committee member) / Department of Psychology (Contributor) / School of Public Affairs (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Human potential is characterized by our ability to think flexibly and develop novel solutions to problems. In cognitive neuroscience, problem solving is studied using various tasks. For example, IQ can be tested using the RAVEN, which measures abstract reasoning. Analytical problem solving can be tested using algebra, and insight can be tested using a nine-dot test. Our class of problem-solving tasks blends analytical and insight processes. This can be done by measuring multiply-constrained problem solving (MCPS). MCPS occurs when an individual problem has several solutions, but when grouped with simultaneous problems only one correct solution presents itself. The most common test for MCPS is known at the CRAT, or compound remote associate task. For example, when given the three target words “water, skate, and cream” there are many compound associates that can be assigned each of the target words individually (i.e. salt-water, roller-skate, whipped-cream), but only one that works with all three (ice-water, ice-skate, ice-cream).
This thesis is a tutorial for a MATLAB user-interface, known as EEGLAB. Cognitive and neural correlates of analytical and insight processes were evaluated and analyzed in the CRAT using EEG. It was hypothesized that different EEG signals will be measured for analytical versus insight problem solving, primarily observed in the gamma wave production. The data was interpreted using EEGLAB, which allows psychological processes to be quantified based on physiological response. I have written a tutorial showing how to process the EEG signal through filtering, extracting epochs, artifact detection, independent component analysis, and the production of a time – frequency plot. This project has combined my interest in psychology with my knowledge of engineering and expand my knowledge of bioinstrumentation.
This thesis is a tutorial for a MATLAB user-interface, known as EEGLAB. Cognitive and neural correlates of analytical and insight processes were evaluated and analyzed in the CRAT using EEG. It was hypothesized that different EEG signals will be measured for analytical versus insight problem solving, primarily observed in the gamma wave production. The data was interpreted using EEGLAB, which allows psychological processes to be quantified based on physiological response. I have written a tutorial showing how to process the EEG signal through filtering, extracting epochs, artifact detection, independent component analysis, and the production of a time – frequency plot. This project has combined my interest in psychology with my knowledge of engineering and expand my knowledge of bioinstrumentation.
ContributorsCobban, Morgan Elizabeth (Author) / Brewer, Gene (Thesis director) / Ellis, Derek (Committee member) / Harrington Bioengineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
The purpose of this project was to extend Whitehead 2016 to determine what neural substrates supported conflict-mediated learning. Unfortunately, as a result of the COVID-19 pandemic we were unable to address this. To repurpose the collected data, an analysis of which features of the Flanker task subjects were learning was conducted. Specifically, we wanted to know if subjects were learning by using the flanking stimuli to predict the central target or vice versa. Over 14 blocks comprised of 120 trials, we found that subjects made more stroop errors than flanker and target errors, indicating subjects were responding to stimuli in context of the flanker rather than the stroop effect.
ContributorsSobelman, Reanna Hayley (Author) / Blais, Chris (Thesis director) / Brewer, Gene (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2020-12
Description
In everyday life, unfocused attention can be detrimental to life either through driving vehicles, cutting vegetables, and learning new languages. In order to increase sustained attention, Binaural Beats were introduced. Binaural Beats have two different frequency tones which oscillate to produce different effects. Each of these beats operates at different frequencies thus having different sound production: theta, delta, alpha, beta, and gamma. In the experiment beta Binaural Beats with frequencies of 200 and 216 Hertz, Hz (unit of measurement for frequency), were used with a control of 200 Hz flat noise. The experiment utilized the psychomotor vigilance task to measure changes in response times and utilized Affectiva to measure changes in facial musculature. The response times were then analyzed to explain why the Binaural Beats condition had significantly shorter response times compared to the control group throughout the task. In terms of emotional change, some trends were noticed for the Binaural Beats and the control condition; however, none of the trends were significant. Moving forward with the experiment, an increased number of participants can be recorded to strengthen the validity and test different frequencies of Binaural Beats for accuracy.
ContributorsObulasetty, Mohitha (Author) / Brewer, Gene (Thesis director) / Wingert, Kimberly (Committee member) / Department of Psychology (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
Recognition memory is examined by exposing a person to a stimulus and later prompting them with the same stimulus to examine their ability to accurately acknowledge that the stimulus was previously encountered (Kahana, 2012). In recognition memory, confidence ratings are taken during the testing phase to assess how confident the participant is that the old-new judgment that they just made is accurate (Busey et al., 2000). Confidence is a metacognitive assessment about the accuracy of perception of decision making based on the amount, speed, and clarity of thoughts that come to mind (Dunlosky and Metcalfe, 2008). The goal of the current study is to better understand how assessing recognition memory using a variety of test procedures influences memory accuracy using the signal detection theory and adding multiple confidence scales that vary in granularity. Based on the previous literature, it is hypothesized that; 1) tasks ordered sequentially will produce greater recognition accuracy (d') than the simultaneous (dual task) condition; 2) confidence scale of 3 points will produce a larger d' than the 7 point scale, and the 7 point scale will produce a larger d' than the 100 point scale; and 3) task mode (ordered vs. sequenced) will interact with confidence scale granularity to predict memory accuracy, such that sequential judgments lessen demands on working memory that come from maintaining an increasing number of decision criteria in comparison to the dual task. Results indicated all hypotheses were not upheld. The findings suggest that taxing working memory may not affect decisional accuracy on a recognition task incorporating confidence judgments.
ContributorsSullivan, Krysten Jennifer (Author) / Brewer, Gene (Thesis director) / Blais, Chris (Committee member) / Davis, Mary (Committee member) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2017-12
Description
The frontostriatal reward circuit serves an underlying role in reward processing, cognitive planning, and motor control in the context of achieving a goal. Furthermore, research suggests a relationship between the reward circuits and behavior expressed in Attention Deficit Hyperactivity Disorder (ADHD); however, the specific structural differences of the reward circuits in those with ADHD remain ambiguous. Diffusion tensor imaging (DTI) techniques were used to analyze diffusion weighted magnetic resonance imaging (DWI) data in order to examine the structural connectivity of frontostriatal reward pathways in ADHD adolescents compared to typically developing (TD) adolescents. It was hypothesized that measures of impulsivity would be predicted by white matter tract integrity measures in frontostriatal tracts related to affective processing (ventromedial prefrontal cortex to ventral striatum, vmPFC) in adolescents with ADHD, and that there would be reduced tract integrity in tracts related to executive control (dorsolateral prefrontal and anterior cingulate cortex—dlPFC and ACC, respectively). Frontostriatal tracts as well as the hippocampus and amygdala were examined in relation to age and impulsivity using both correlation and regression models. Results indicated that impulsivity declined with age in the TD group while no significant trend was identified for the ADHD group. The hypotheses were not supported and results for both predictions on the affective and executive circuits showed opposite trends from what was expected.
ContributorsHarrison, Sydney Rae (Author) / McClure, Samuel (Thesis director) / Brewer, Gene (Committee member) / Davis, Mary (Committee member) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2017-12
Description
Prospective memory refers to the ability to form and carry out an intention. Prospective memory can be further divided into the subcategories of episodic and habitual prospective memory, which differ in their task demands and electrophysiological components. The focus of the present study is on habitual prospective memory, which is the ability to routinize and consistently fulfill intentions that occur repeatedly. This skill is especially useful for populations with impaired executive functioning and/or memory deficits, such as those with acquired brain injuries. The purpose of this study is to analyze the performance of an undergraduate population on a habitual prospective memory task in order to create a baseline model for comparison with a clinical population. Evidence of habitization to the prospective memory component of the task was discovered, as demonstrated by speeded ongoing-task response times and reduced interference to prospective memory cues. Ongoing task accuracy and prospective memory cue detection were very high, while commission errors were very few, demonstrating ease of the task for neurotypical populations. We speculate that people with acquired brain injuries will not show as significant of a quickening of response times, nor such accurate performance on prospective memory cue trials or the commission error phase.
ContributorsArnett, Ciera Renee (Author) / Brewer, Gene (Thesis director) / Blais, Christopher (Committee member) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2017-12
Description
Problem solving is a crucial skill needed to accomplish everyday tasks and overcome potential obstacles. One way to measure individual differences in problem solving ability is through performance differences on multiply-constrained problem solving tasks. Multiple cognitive processes are involved in multiply-constrained problem solving. An individual uses prospective metacognitive monitoring judgments to gauge future allocation of resources before engaging in the necessary semantic search. Problem solvers also vary in their semantic search strategies, and use either an active analytical strategy or a passive insight strategy to arrive at asolution. Prospective metacognitive monitoring judgments and solution strategies are two aspects of the problem solving process that occur at specific points in the process while motivation influences problem solving throughout the process. The goal of this study is to examine prospective metacognitive judgments, problem solving accuracy, solution strategy, and motivation in multiply-constrained problem solving. Motivation was manipulated using a performance based monetary incentive. Participants self reported prospective Feeling-of-Knowing judgments after brief exposure to the problem, and solution strategy ratings after each problem. No significant differences were found to support the effect of motivation on problem solving accuracy, prospective metacognitive judgments, relative accuracy, or solution strategies. Significant differences were found between groups when comparing the number of problems skipped, indicating that participants were sensitive to the incentive structure. The findings suggest that motivation may not be an overarching mediator in multiply-constrained problem solving or problem solving may require a specific type of incentive structure to increase accuracy. However, little is known in the research literature about the type of incentive structure needed to consistently increase individual motivation.
ContributorsCohen, Aaron Sayre (Author) / Brewer, Gene (Thesis director) / Ellis, Derek (Committee member) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05