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.

The human brain controls a person's actions and reactions. In this study, the main objective is to quantify reaction time towards a change of visual event and figuring out the inherent relationship between response time and corresponding brain activities. Furthermore, which parts of the human brain are responsible for the reaction time is also of interest. As electroencephalogram (EEG) signals are proportional to the change of brain functionalities with time, EEG signals from different locations of the brain are used as indicators of brain activities. As the different channels are from different parts of our brain, identifying most relevant channels can provide the idea of responsible brain locations. In this study, response time is estimated using EEG signal features from time, frequency and time-frequency domain. Regression-based estimation using the full data-set results in RMSE (Root Mean Square Error) of 99.5 milliseconds and a correlation value of 0.57. However, the addition of non-EEG features with the existing features gives RMSE of 101.7 ms and a correlation value of 0.58. Using the same analysis with a custom data-set provides RMSE of 135.7 milliseconds and a correlation value of 0.69. Classification-based estimation provides 79% & 72% of accuracy for binary and 3-class classication respectively. Classification of extremes (high-low) results in 95% of accuracy. Combining recursive feature elimination, tree-based feature importance, and mutual feature information method, important channels, and features are isolated based on the best result. As human response time is not solely dependent on brain activities, it requires additional information about the subject to improve the reaction time estimation.

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.

In the study of the human brain’s ability to multitask, there are two perspectives: concurrent multitasking (performing multiple tasks simultaneously) and sequential multitasking (switching between tasks). The goal of this study is to investigate the human brain’s ability to “multitask” with multiple demanding stimuli of approximately equal concentration, from an electrophysiological perspective different than that of stimuli which don’t require full attention or exhibit impulsive multitasking responses. This study investigates the P3 component which has been experimentally proven to be associated with mental workload through information processing and cognitive function in visual and auditory tasks, where in the multitasking domain the greater attention elicited, the larger P3 waves are produced. This experiment compares the amplitude of the P3 component of individual stimulus presentation to that of multitasking trials, taking note of the brain workload. This study questions if the average wave amplitude in a multitasking ERP experiment will be the same as the grand average when performing the two tasks individually with respect to the P3 component. The hypothesis is that the P3 amplitude will be smaller in the multitasking trial than in the individual stimulus presentation, indicating that the brain is not actually concentrating on both tasks at once (sequential multitasking instead of concurrent) and that the brain is not focusing on each stimulus to the same degree when it was presented individually. Twenty undergraduate students at Barrett, the Honors College at Arizona State University (10 males and 10 females, with a mean age of 18.75 years, SD= 1.517) right handed, with normal or corrected visual acuity, English as first language, and no evidence of neurological compromise participated in the study. The experiment results revealed that one- hundred percent of participants undergo sequential multitasking in the presence of two demanding stimuli in the electrophysiological data, behavioral data, and subjective data. In this particular study, these findings indicate that the presence of additional demanding stimuli causes the workload of the brain to decrease as attention deviates in a bottleneck process to the multiple requisitions for focus, indicated by a reduced P3 voltage amplitude with the multitasking stimuli when compared to the independent. This study illustrates the feasible replication of P3 cognitive workload results for demanding stimuli, not only impulsive-response experiments, to suggest the brain’s tendency to undergo sequential multitasking when faced with multiple demanding stimuli. In brief, this study demonstrates that when higher cognitive processing is required to interpret and respond to the stimuli, the human brain results to sequential multitasking (task- switching, not concurrent multitasking) in the face of more challenging problems with each stimulus requiring a higher level of focus, workload, and attention.

Music and emotions have been studied frequently in the past as well as music and memory. However, these three items don’t have as much research grouped together. Further, this research does not also encompass culture. In my research, the aim was to examine the relationship between music, memory, emotion, and culture of gender. The hypothesis was that women had more emotions linked to music than men. We gave 416 students an animal fluency task, a letter fluency task, six cultural fluency tasks, and a cultural identity survey. We used a t-test and created a graph to analyze my data. After administering my tasks, we found that women had recalled more adjectives linked to music than men. However, there was not a statistically significant difference between the number of adjectives with emotional valence between men and women, indicating that there was no relationship between gender and emotion in regards to music. The limitations on this study included the descriptions on how to complete the task, the cultural norms of the participants, and the disparity between the number of female and male participants. In a future study, it is necessary to be more specific in what is desired from the participants and to pay close attention to shifting gender norms. Further, we would also like to see how the results from future research can impact music therapy for memory-related mood disorders.

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.

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.

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.

Childhood Apraxia of Speech (CAS) is a severe motor speech disorder that is difficult to diagnose as there is currently no gold-standard measurement to differentiate between CAS and other speech disorders. In the present study, we investigate underlying biomarkers associated with CAS in addition to enhanced phenotyping through behavioral testing. Cortical electrophysiological measures were utilized to investigate differences in neural activation in response to native and non-native vowel contrasts between children with CAS and typically developing peers. Genetic analysis included full exome sequencing of a child with CAS and his unaffected parents in order to uncover underlying genetic variation that may be causal to the child’s severely impaired speech and language. Enhanced phenotyping was completed through extensive behavioral testing, including speech, language, reading, spelling, phonological awareness, gross/fine motor, and oral and hand motor tasks. Results from cortical electrophysiological measures are consistent with previous evidence of a heightened neural response to non-native sounds in CAS, potentially indicating over specified phonological representations in this population. Results of exome sequencing suggest multiple genetic variations contributing to the severely affected phenotype in the child and provide further evidence of heterogeneous genomic pathways associated with CAS. Finally, results of behavioral testing demonstrate significant impairments evident across tasks in CAS, suggesting underlying sequential processing deficits in multiple domains. Overall, these results have the potential to delineate functional pathways from genetic variations to the brain to observable behavioral phenotypes and motivate the development of preventative and targeted treatment approaches.

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.