Tag: Don Tucker

Mapping the Human Primary Somatosensory Cortex Using Dense-array EEG: An Analysis of the Somatosensory Evoked Potential

Presenter: Kyle Morgan

Mentor: Don Tucker

AM Poster Presentation

Poster 31

In principle, dense-array EEG (dEEG) technology has the ability to localize cortical brain activity with adequate spatial resolution such that anatomically and functionally distinct regions can be studied. The present study employs dEEG to map activity of the primary somatosensory cortex (SI), which is functionally and anatomically defined. EEG recordings were acquired from 10 participants as their thumbs were stimulated by a custom-made piezoelectric stimulator. Early components of the somatosensory evoked potential (SEP), which reflect activity from SI, were evaluated in individual participants to assess topographic distribution at the scalp. In a subset of participants, we build high-resolution electric head models that describe how current propagates from the cortex to the scalp surface, where the SEP is measured, and we use this model to localize the early SEP components. We report on the localization accuracy relative to the expected location (SI).

The Effects of Red and Green Colored Word Stimuli on Neural Processing and Behavior during an Emotional Stroop Task: An Event-Related Potential Investigation

Presenter: Katia Krane

Faculty Mentor: Don Tucker, Anita Christie

Presentation Type: Poster 73

Primary Research Area: Science

Major: Human Physiology, Psychology

Western associations of colors, especially of red and green, influence how individuals consciously perceive the meanings of these colors. However, very little research has investigated the underlying neural processes of localized colors presented as meaningful stimuli, like words, and the possible effects these colors have on behavior. The aim of this study was to investigate initial neural responses to red and green colored word stimuli and the effects of these colors on behavior, including working memory and response time. Using dense-array EEG, event-related potentials (ERPs) were recorded following presentation of word stimuli in red and green ink. ERPs represent measurements of post-synaptic potentials following a response evoking stimulus, in this case red and green colored words, to show real time neural processing of stimuli immediately after presentation. Additionally, memory recall and average response times for each color category were recorded. Participants recalled more red colored words than green, however, did not show significant differences in average response times during the emotional Stroop task, indicating that color may impact working memory but not response performance during the Stroop task. ERP waveform amplitude differences between color categories in components known to be involved in visual processing and discrimination, such as the C1, P1 and N1, suggest that differences in color perception occur quickly post stimulus presentation. These results suggest a bottom-up cognitive mechanism of color perception that may influence behaviors, such as working memory. Associations of the colors red and green may not simply be arbitrary, but linked to underlying differences in neural processing which may imply biases in previous research in which an emotional Stroop task was used to investigate behavioral and neural responses.

Dissociation Phenomenon: Performance Differences During Divided Attention Task

Presenter(s): Madeline Rogers − Psychology

Faculty Mentor(s): Jenn Lewis, Don Tucker

Poster 124

Research Area: Social Science

Dissociation is a mental process characterized by a lack of connection in a person’s cognition, memory or sense of identity. Often seen in clinical populations and as a normative trait, increased dissociative tendencies have been suggested to be an adaptive mechanism used to enhance performance and/or personal experience. The current study sought to replicate previous research that investigated the effects of dissociation on performance and memory under different attentional settings. Undergraduate students, grouped based on their results of the Dissociative Experiences Scale (DES: Bernstein & Putnam, 1986), participated in an emotional Stroop task and free recall memory task under selective and divided attention conditions. Consistent with previous findings, low-DES participants became significantly slower after switching to the divided attention condition. Unexpectedly, high-DES participants did not show significant differences in response time after switching from selective to divided attention conditions, suggesting that added difficulty of the task did not impair performance. Both groups remembered significantly more trauma-related words than neutral words under both conditions. The results of this study replicated some of the results of earlier studies, but it also failed to replicate some effects. This research provides more evidence towards discerning what effects dissociation has on cognition, but if and how dissociative tendencies act as an adaptive mechanism for cognition remains unclear.

Cortical Thickness: An Introduction and Comprehensive Review of the Current Literature

Presenter(s): Ha Eun Kim − Psychology

Faculty Mentor(s): Don Tucher, Ariel Wightman

Poster 31

Research Area: Neuroscience

Cortical thickness of the cerebral cortex provides valuable information about normal and abnormal brain anatomy. For the past 30 years, much research and studies have revealed the association of cortical thickness and various neurodevelopmental disorders as well as regional differences in normal brain function. In light of this research, it is crucial to understand and summarize what has been discovered so far. The aim of this review was to examine all available published cortical thickness research on Google Scholar and to provide a comprehensive summary of current studies. The literature search encompassed all relevant cortical thickness studies published until January 2017 on Google Scholar. Through several inspections, initially found 134 papers were narrowed down to 119 papers. The papers were inspected twice and were categorized into five different groups according to the paper’s relevant topics in terms of cortical thickness as follows: I, brief summary of the different cortical thickness extraction mechanisms; II, studies in healthy normal participants; III, studies in neurodevelopmental disorders; IV, studies in neuropathological disorders and V, studies in all other disorders. Summaries of research on more specific disorders were addressed in each subcategory. These outcomes indicate the importance of cortical thickness research and need for further analysis in the future.

The Relationship Between Self-Reported Mindfulness and the P300

Presenter(s): Josephine Swift

Faculty Mentor(s): Jennifer Lewis & Don Tucker

Poster 95

Session: Social Sciences & Humanities

Mindfulness is a state of awareness that allows an individual to more effectively monitor their cognition and emotions. The ways in which mindfulness impacts aspects of cognition, including attention and attentional control, are still being researched. The current study examines how dispositional mindfulness is related to individuals’ attention and attentional control as measured through dense-array EEG (dEEG). We examined participant’s (n=72) scores on the Five Facet Mindfulness Questionnaire (FFMQ; Baer, Smith, Hopkins, Krietemeyer, & Toney, 2006) and their event-related potentials (ERPs) generated from completing the color-word Stroop task modified for dEEG recording. Response times were also recorded. ERP waveform amplitude differences for the P300, an ERP associated with attentional processes, did not significantly differ by category (i.e., Incongruent, Congruent). However, preliminary analyses showed a relationship between self-reported mindfulness and the amplitude of the P300 (across both categories), whereas higher scores on the FFMQ were associated with attenuated P300 amplitudes. Decreased P300 amplitudes may indicate the deployment of less attentional resources. It’s possible that individuals who are more mindful, have naturally increased attention and therefore require less attentional resources in a cognitively demanding task. Mindfulness has been found to be an effective intervention for mood disorders, particularly anxiety disorders (Blanck et al. 2018). Understanding the particular ways that mindfulness impacts cognition may lead to a further understanding of the mechanisms by which mindfulness improves anxiety symptoms and thus improve treatment.

The Effect of Delta Frequency Music on Insomniac Sleep Onset Latency

Presenter(s): Faith Collins

Faculty Mentor(s): Don Tucker

Oral Session 2 SW

Insomnia, a common sleep disorder, is associated with difficulties initiating sleep (i.e., sleep onset latency). Pharmacological interventions provide moderate relief, but because of habituation and growing problems with substance abuse and addiction, there has been a push by the National Institutes of Health (NIH) to identify non-pharmacological interventions for such conditions. One possible intervention for insomnia is listening to music to improve sleep onset latency. This study is a 3-week intervention in which participants will listen to 45 minutes of slow, rhythmic music as they are falling asleep. Tononi et al., (2010) administered brief tones at 0.8 and 2 Hz (delta frequency), a rate that approximates the natural cellular oscillation of cortical neurons during sleep. They found these tones improved sleep slow waves. Thus, we hypothesize that delta frequency music will improve sleep latency and catalyze the transition into slow wave sleep, similar to the results reported by Tononi, (2010). An a priori power analysis suggested this study will require 10 subjects. The inclusion criteria are aged 18- 65, and a Pittsburgh Sleep Quality Index (PSQI) score >5. The exclusion criterion is a yes response to any item on the Self- reported Comorbidity Questionnaire (SCQ). A repeated-measures multivariate analysis of variance (MANOVA) including within and between interactions will be utilized. The independent variable is group (normal sleepers and insomniacs). Dependent measures include pre- post-PSQI score, sleep onset latency in minutes, a Likert scale sleep quality report, and a sleep log of sleep onset and sleep time in minutes.