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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Subject: search.filters.subject.Cognitive psychology

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    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.
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    Determining the Mechanisms of Spoken Language Processing Delay for Children with Cochlear Implants
    (2023) Blomquist, Christina Marie; Edwards, Jan R; Newman, Rochelle S; Hearing and Speech Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    The long-term objective of this project was to better understand how shorter auditory experience and spectral degradation of the cochlear implant (CI) signal impact spoken language processing in deaf children with CIs. The specific objective of this research was to utilize psycholinguistic methods to investigate the mechanisms underlying observed delays in spoken word recognition and the access of networks of semantically related words in the lexicon, which are both vital components for efficient spoken language comprehension. The first experiment used eye-tracking to investigate the contributions of early auditory deprivation and the degraded CI signal to spoken word recognition delays in children with CIs. Performance of children with CIs was compared to various typical hearing (TH) control groups matched for either chronological age or hearing age, and who heard either clear or vocoded speech. The second experiment investigated semantic processing in the face of a spectrally degraded signal (TH adult listeners presented with vocoded speech) by recording event-related potentials, specifically the N400. Results children with CIs show slower lexical access and less immediate lexical competition, and while early hearing experience supports more efficient recognition, much of these observed delays can be attributed to listening to a degraded signal in the moment, as children with TH demonstrate similar patterns of processing when presented with vocoded speech. However, some group differences remain, specifically children with CIs show slower speed of lexical access and longer-lasting competition, suggesting potential effects of learning from a degraded speech signal. With regards to higher-level semantic processing, TH adult listeners demonstrate more limited access of semantic networks when presented with a degraded speech signal. This finding suggests that uncertainty due the degraded speech signal may lead to less immediate cascading processing at both the word-level and higher-level semantic processing. Clinically, these results highlight the importance of early cochlear implantation and maximizing access to spectral detail in the speech signal for children with CIs. Additionally, it is possible that some of the delays in spoken language processing are the result of an alternative listening strategy that may be engaged to reduce the chance of incorrect predictions, thus preventing costly revision processes.
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    Information Uncertainty Influences Learning Strategy from Sequentially Delayed Rewards
    (2023) Maulhardt, Sean Richard; Charpentier, Caroline; Psychology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    The problem of temporal credit assignment has long been posed as a nontrivial obstacle to identifying signal from data. However, human solutions in complex environments, involving repeated and intervening decisions, as well as uncertainty in reward timing, remain elusive. To this end, our task manipulated uncertainty via the amount of information given in their feedback stage. Using computational modeling, two learning strategies were developed that differentiated participants’ updates of sequentially delayed rewards: eligibility trace whereby previously selected actions are updated as a function of the temporal sequence - and tabular update - whereby additional feedback information is used to only update systematically-related rather than randomly related past actions. In both models, values were discounted over time with an exponential decay. We hypothesized that higher uncertainty would be associated with (i) a switch from tabular to eligibility strategy and (ii) higher rates of discounting. Participants’ data (N = 142) confirmed our first hypothesis, additionally revealing an effect of the starting condition. However, our discounting hypothesis had only weak evidence of an effect and remains an open question for future studies. We explore potential explanations for these effects and possibilities of future directions, models, and designs.
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    ROLE OF PROJECTIONS FROM ORBITOFRONTAL CORTEX TO DORSAL STRIATUM IN INCUBATION OF OXYCDONE CRAVING
    (2023) Lin, Hongyu; Li, Xuan; Psychology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    Oxycodone seeking progressively increases during abstinence and maintains for an extended period, a phenomenon termed incubation of oxycodone craving. We previously found that the orbitofrontal cortex (OFC) plays a causal role in this incubation. Here, we aimed to identify critical downstream regions of OFC in incubation of oxycodone craving by focusing on the central to medial portion of the dorsal striatum (DS), based on previous anatomical evidence. We first measured projection-specific activation on abstinence day 15 seeking test by using cholera toxin b (retrograde tracer, injected into DS) +Fos (activity marker) double-labeling in the OFC. Next, we determined the effect of pharmacological reversible inactivation of DS on incubated oxycodone seeking on abstinence day 15. We then used an anatomical asymmetrical disconnection procedure to determine whether OFC to DS projections contribute to incubated oxycodone seeking.
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    Relations Between Latent Episodic Memory, Nap Habituality, and the Cortex During Childhood
    (2023) Allard, Tamara Lynn; Riggins, Tracy; Psychology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    During childhood, episodic memory demonstrates marked improvements that are supported by the protracted development of the hippocampus and a larger network of cortical regions. To date, most research has focused on associations with the hippocampus in this age group. Few studies have explored the contribution of cortical regions and no studies have explored this longitudinally. Thus, the first aim of this dissertation was to examine the longitudinal co-development of cortical thickness and surface area in memory-related cortical regions with a latent episodic memory variable in 4- to 8-year-old children (N = 177). Findings, uncorrected for multiple comparisons, demonstrated that a thinner cortex in multiple episodic memory network regions (i.e., inferior frontal gyrus, inferior parietal sulcus, lingual gyrus, middle temporal gyrus, precuneus, lateral occipital cortex, superior frontal gyrus, superior parietal lobule, superior temporal gyrus, and temporal pole) at age 4 predicted more rapid improvements in memory performance from age 4 to 6 years. Similarly, greater surface area in the precuneus and less surface area in the medial orbitofrontal gyrus at age 4 also predicted more rapid improvements in memory performance from age 4 to 6 years. Additionally, results revealed that several regions demonstrate parallel co-development with latent episodic memory performance from age 4 to 8 years. Specifically, greater changes in cortical thickness and surface area of the entorhinal cortex were associated with greater changes in memory from age 4 to 6 years. Furthermore, cortical thickness of entorhinal cortex and surface area of anterior cingulate cortex, entorhinal cortex, inferior parietal sulcus, lingual gyrus, and superior temporal gyrus showed co-development with latent episodic memory from age 6 to 8 years. Together, these findings suggest that cortical thickness and surface area of the episodic memory network support improvements in memory performance during childhood. However, these findings did not survive correction for multiple comparisons. Although age-related differences were one focus of this investigation, individual differences were another. Specifically, during childhood children transition away from afternoon napping. This transition has previously been associated with differences in memory consolidation abilities and hippocampal maturation. These associations suggest that habitual nappers require more regular sleep to consolidate memories due to an immature episodic memory network. However, limited work has examined these associations outside the hippocampus. Therefore, the second aim of this dissertation was to examine whether regions that support longitudinal memory development differ as a function of nap habituality (N = 44). Findings revealed significant differences in cortical thickness of right inferior frontal gyrus and surface area of lateral occipital cortex, such that non-nappers demonstrated a thinner cortex and greater surface area in these regions compared to nappers, though these findings did not survive correction for multiple comparisons. Thus, although there is some evidence that memory-related cortical regions may differ based on nap habituality, additional work is needed to support this claim. Together this dissertation provides new data on the co-development of memory with brain structure in the episodic memory network and identifies individual differences that may be associated with these brain structures.
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    Perceptual Decision Impairments in Obsessive-Compulsive Disorder: State and Trait Symptom Effects and The Role of Working Memory
    (2020) Kaplan, Claire; Solway, Alec; Psychology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    Computational models of decision making have identified a relationship between obsessive-compulsive symptomatology and impairments in perceptual evidence accumulation. Past studies have suggested that these impairments in perceptual processing give rise to clusters of OCD symptoms (for example, not effectively “perceiving” that a door is locked or that one’s hands are clean gives rise to compulsive checking or washing). That interpretation has implications for our understanding of the disorder and warrants further testing; one way to investigate that is to determine whether such impairments correlate better with state-level symptoms (i.e., obsessions and compulsions during task performance) or trait-level symptoms (i.e., in general/past week). Using hierarchical drift-diffusion modeling, the current study examines this question in consideration of the alternate possibility that these decision impairments are simply a reflection of off-task processing of active obsessions and compulsions. We also examine whether working memory may mitigate such impairments, in light of prior studies that have associated larger working memory spans with better suppression of distractors and with faster perceptual evidence accumulation. 161 adults completed the random dot-motion task, OSPAN working memory task, and OCD symptom questionnaires online. Participants who reported greater obsessive-compulsive symptoms demonstrated slower evidence accumulation (“drift rate”) in the dot-motion task. These drift rate reductions were better explained by state-level symptom severity than trait-level severity. Working memory span showed a significant negative interaction with state-level symptom score on drift rate, however only for the easiest trials. While the current study does not negate a role of perceptual evidence accumulation deficits in the pathogenesis of OCD, these findings support the possibility that such deficits may also be brought about by active symptoms during task execution. We discuss using impairments in drift rate to approximate attentional bias for off-task symptoms, as this provides a novel computational framework in closer alignment with existing clinical models of OCD.
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    DYNAMIC CHANGES IN FEEDBACK PROCESSING AND COGNITIVE CONTROL NETWORKS DURING A GAMBLING TASK: A SOURCE ANALYSIS OF EEG AMPLITUDE AND PHASE MEASURES
    (2021) Tootell, Anne V; Bernat, Edward; Psychology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    A wealth of cognitive and clinical psychology research has been devoted to better understanding the mechanism underlying goal-directed behavior. Decades of research in this area have highlighted the importance of salience and cognitive control networks in processing task feedback for improving goal-directed performance on subsequent trials. However, discrepancies in findings and methodological limitations have led to competing conceptual models of task performance with untested theoretical hypotheses. The current study aimed to evaluate a leading integrative theory of task performance (the Expected Value of Control theory), by assessing activity and functional connectivity of ACC (indexing salience) and dlPFC (indexing control) regions on the timescale of milliseconds. Time-frequency event-related potential (TF-ERP) measures were assessed in the theta (3-7 Hz) frequency range based on cortical source localization analysis. Hypotheses centered on the theory that ACC activity precedes engagement of the dlPFC and cognitive control network. Analyses are based on an archival dataset of 154 undergraduates who completed a gambling task with the goal to win the most money possible. Supporting the hypotheses, TF and source localization analyses revealed that activity in the ACC did precede functional connectivity with the dlPFC. In fact, both the ACC and dlPFC became active before functional connectivity was observed between these regions, suggesting that initial feedback processing occurred separately in each area before broader inter-region communication. This novel finding supports the Expected Value of Control theory and adds to the field’s current understanding of feedback and cognitive control processing during task performance.
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    Exploring Relations Between Memory and Internalizing and Externalizing Behaviors in Childhood
    (2021) Munshell, Paige; Riggins, Tracy
    There is a growing field of research which suggests internalizing and externalizing disorders cause disruptions in cognitive functioning, including memory. This association has primarily been explored in adults. This honors thesis explores the potential connection between mnemonic discrimination as a measure of episodic memory and internalizing and externalizing behaviors in young children. Researchers collected data on memory using a Mnemonic Similarity Task (MST) in children between 3 and 5 years of age and related their performance to ratings of their internalizing and externalizing behavior from the Child Behavior Checklist (CBCL) completed by a parent or guardian. Results did not support the hypothesis that internalizing and externalizing behaviors were related to poor episodic memory, as has been shown in adult populations. Future research with older children should be conducted in order to understand when during development that internalizing and externalizing behaviors begin to inhibit episodic memory.
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    Is nap status related to memory, sleep physiology, and the hippocampus in early childhood?
    (2020) Allard, Tamara L; Riggins, Tracy; Psychology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    Research suggests there may be links between developmental changes in sleep (e.g., transition out of a nap), memory, and brain (specifically, hippocampus). The purpose of this investigation was to explore differences in sleep physiology, visuospatial memory, and hippocampal volume based on nap status. Participants were 3 to 5-year-old children (n=51) who were habitual nappers (napping >5 days/week), semi-habitual nappers (3–4 days/week), or non-nappers (<2 days/week). Participants completed a memory task before and after a wake and nap session. Polysomnography (PSG) and hippocampal volumes were also assessed. Findings demonstrated that, regardless of nap status, children performed better on a memory task following a nap. PSG revealed that habitual nappers spent marginally more time in nREM2 sleep and less time in SWS compared to semi-habitual nappers. Finally, non-nappers demonstrated a larger hippocampus than the other groups. These findings support the suggestion that developmental differences in these domains are related during childhood.
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    Conflict and Competition between Model-based and Model-free Control
    (2020) Lei, Yuqing; Solway, Alec; Psychology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    There are two learning systems behind human decision-making: the model-based (MB) system and the model-free (MF) system. While they both contribute to decision-making behaviors, it is not clear how the two systems interact to formulate a single decision, especially when they are in conflict. This present thesis defines decision conflict between the systems in two popular binary-choice tasks: Daw’s Two-step task and Kool’s Rocket Task. We used hierarchical modeling to identify conflict-related changes during decision process using the Drift-Diffusion Model (DDM). Evidence showed that the MB system compromises when there is a conflict with the MF system, whether the conflict is on the valuational level or action level. We also looked at how a key component of obsessive compulsive disorder (OCD), the cognitive self-consciousness (CSC), affects the two learning systems during decision.