College of Behavioral & Social Sciences
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The collections in this community comprise faculty research works, as well as graduate theses and dissertations..
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Item Temporal Processing in Adults Who Stutter(2024-05-10) Wathen, Jasmine; Anderson, Samira; Ratner, Nan BernsteinStuttering is often thought of as simply an impairment in speech production. However, some studies have indicated that people who stutter (PWS) also experience temporal processing impairments which affect perception of speech. In particular, previous behavioral and electrophysiology (EEG) studies have demonstrated time delays in processing speech stimuli in PWS. Most research to this date has only examined these timing delays at the level of the cerebral cortex, which represents the later stages of processing. Very few studies have examined delays at the level of the brainstem, and no study has looked at processing in both the cortex and the brainstem. This study recruited adults who stutter (AWS) and adults who do not stutter (AWNS) to examine how each group processes speech at both subcortical and cortical levels. Participants completed a perceptual test to determine how well they perceived speech and underwent EEG testing to measure cortical and subcortical electrical activity while listening to speech stimuli. Compared to AWNS, AWS showed poorer neural representations of the speech stimulus in the brainstem and delays at the cortical level. Perceptual testing in AWS also seemed to show a poorer perception of phoneme boundaries in words compared to AWNS. Our research suggests that temporal processing deficits are a factor in stuttering and that these deficits arise at early levels of the auditory system. These findings might call for an update of current speech therapy methods to address the timing delays that AWS experience in speech processing.Item MULTIMODAL ANALYSIS OF NEURAL SIGNALS RELATED TO SOURCE MEMORY ENCODING IN YOUNG CHILDREN(2024) Lei, Yuqing; Riggins, Tracy; Psychology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The emergence of source memory is an important milestone during memory development. Decades of research has explored neural correlates of source memory using electroencephalography (EEG) and functional magnetic resonance imaging (fMRI). However, connections between findings from the two approaches, particularly within children, remain unclear. This dissertation identified fMRI-informed cortical sources of two EEG signals during memory encoding, the P2 and the late slow wave (LSW), that predicted subsequent source memory performance in a sample of children aged 4 to 8 years. Both P2 and LSW were source localized to cortical areas of the medial temporal lobe (MTL), reflecting MTL’s crucial role in both early-stage information processing and late-stage integration of memory, which also validated LSW’s suspected role in memory updating. The P2 effect was localized to all six tested subregions of cortical MTL in both left and right hemispheres, whereas the LSW effect was only present in the parahippocampal cortex and entorhinal cortex. P2 was additionally localized to multiple areas in the frontoparietal network, a cortical network known as the “attention network”, highlighting interactions between memory encoding and other cognitive functions. These results reflect the importance of considering both spatial and temporal aspects of neural activity to decode memory mechanism, and demonstrated the potential of combining multimodal measures in children, paving the way for future developmental research.Item Effects of Action-Outcome Agency on Feedback Processing(2016) Tootell, Anne; Bernat, Edward; Psychology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The current study investigated the effect of action-outcome agency, or one’s ability to guide behavior during reinforcement learning, on reward and loss processing in a gambling task. Thirty undergraduates (13 females; M age = 19.57, SD = 2.18) completed two computer gambling tasks, one designed to exhibit high levels of action-outcome agency and one with low, while attached to a 128-channel EEG system. Time-frequency event-related potential (TF- ERP) analysis was conducted on the acquired EEG data. ERP components associated with reward and loss processing were significantly dampened in the low action-outcome agency task relative to the high action-outcome agency task. Interestingly, TF-ERP analysis demonstrated a significant effect of action-outcome agency on gain-loss differences in theta but not delta frequencies, suggesting a more central role of loss processing in guidance of goal-directed behavior. These results challenge components of the well-established predicted response-outcome (PRO) model of reinforcement learning.Item Experimentally Testing the Effect of Parent-Adolescent Conflict on HIV Risk, and Investigation of a Neurobiological Moderator of This Effect(2015) Thomas, Sarah Ann; De Los Reyes, Andres; Psychology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Human immunodeficiency virus (HIV) is a condition in which immune cells become destroyed such that the body may become unable to fight off infections. Engaging in risk-taking behaviors (e.g., substance use) puts people at heightened risk for HIV infection, with mid-to-late adolescents at increasing risk (Leigh & Stall, 1993). Environmental and neurological reasons have been suggested for increased risk-taking among adolescents. First, family-level precursors such as parent-adolescent conflict have been significantly associated with and may pose risk for engaging in substance use and risk-taking (Duncan, Duncan, Biglan, & Ary, 1998). Thus, parent-adolescent conflict may be an important proximal influence on HIV risk behaviors (Lester et al., 2010; Rowe, Wang, Greenbaum, & Liddle, 2008). Yet, the temporal relation between parent-adolescent conflict and adolescent HIV risk-taking behaviors is still unknown. Second, at-risk adolescents may carry a neurobiological predisposition for engaging in trait-like expressions of disinhibited behavior and other risk-taking behaviors (Iacono, Malone, & McGue, 2008). When exposed to interpersonally stressful situations, their likelihood of engagement in HIV risk behaviors may increase. To investigate the role of parent-adolescent conflict in adolescent HIV risk-taking behaviors, 49 adolescents ages 14-17 and their parent were randomly assigned to complete a standardized discussion task to discuss a control topic or a conflict topic. Immediately after the discussion, adolescents completed a laboratory risk-taking measure. In a follow-up visit, eligible adolescents underwent electrophysiological (EEG) recording while completing a task designed to assess the presence of a neurobiological marker for behavioral disinhibition which I hypothesized would moderate the links between conflict and risk-taking. First, findings indicated that during the discussion task, adolescents in the conflict condition evidenced a significantly greater psychophysiological stress response relative to adolescents in the control condition. Second, a neurobiological marker of behavioral disinhibition moderated the relation between discussion condition and adolescent risk-taking, such that adolescents evidencing relatively high levels of a neurobiological marker related to sensation-seeking evidenced greater levels of risk-taking following the conflict condition, relative to the control condition. Lastly, I observed no significant relation between parent-adolescent conflict, the neurobiological marker of behavioral disinhibition and adolescent engagement in real-world risk-taking behavior.Item Event-related potentials in developmental populations.(2005) DeBoer, T.; Scott, L.S.; Nelson, C.A.