The long-term memory system for what is conscious and can be verbalized – declarative memory- is often separated into memory for general facts and memory for personal events (Squire, 2009; Tulving, 2002). Personal semantics share elements of both semantic memory (i.e., they are facts that can be known) and episodic memory (i.e., they are self-related and idiosyncratic; Renoult, Davidson, Palombo, Moscovitch, & Levine, 2012). According to the taxonomy of personal semantics (Renoult et al., 2012), they vary in proximity to either semantic or episodic memory. Towards one end of the continuum, memory for autobiographical facts such as jobs and names of friends were hypothesized to be closer to general facts. Towards the other end of the continuum, repeated events are summaries of the core elements of similar events that happened more than once (e.g., getting coffee at a coffee shop), and they were hypothesized to be closer to episodic memory (i.e., the recollection of a unique event). Self-knowledge involves self-reflection about one’s own personality traits and preferences; it was thought to be the most distinct from semantic and episodic memory. However, little research had compared personal semantics to both semantic and episodic memory, or to one another, and these proposals needed to be tested experimentally. In this thesis, I compared the neural correlates of three types of personal semantics to semantic memory (study 1, 2, 3) and episodic memory (study 1, 2), and to one another (study 1) using functional magnetic resonance imaging (fMRI; study 1) and event related potentials (ERPs; study 2, 3). Moreover, I examined whether temporal orientation modified the personal semantics’ relationship to the typically atemporal semantic memory (study 2, 3) and to the typically past-oriented episodic memory (study 2). In study 1, general facts, autobiographical facts, repeated events, and unique events were compared using fMRI, in a follow-up to an ERP study (Renoult et al., 2016). In our analyses of the hippocampus (HPC) and posterior medial network (Ritchey, Libby, & Ranganath, 2015), general semantics and autobiographical facts were often not significantly different from one another (except for the left posterior HPC), and repeated events and unique events did not differ from one another in any comparison. I observed a small graded increase of brain activity from general facts to autobiographical facts to repeated events and unique events (with a significant linear trend) in the left posterior HPC. In contrast, no memory type differed in the anterior temporal network (Ritchey et al., 2015). In study 2 and 3, self-knowledge was operationalized as the knowledge of one’s own traits, and could concern past (study 2), present (study 2, 3) and future selves (study 2, 3). A neural correlate of recollection, the Late Positive Component (LPC), had a larger mean amplitude for thinking about the self than others (study 2, 3), and thinking about a past and/or future self than the present self (on average for study 2, and significant for study 3). The amplitude of the LPC for thinking about the past and future selves did not differ from an episodic recognition memory task (or present self-knowledge; study 2). Further, the temporal orientation effect was smaller and not significant when we compared thinking about the present and the future traits of others (study 3). The operationalization of the “other” as a close friend or a group of people did not modify this result (study 3). Together, in addition to Renoult et al. (2016), these findings suggest that: the neural correlates of autobiographical facts, repeated events, and self-knowledge do not overlap perfectly with semantic or episodic memory. Moreover, the temporal orientation of the knowledge is one factor that can influence the proximity of the neural correlates of personal semantics to either semantic or episodic memory.

xiii, 163 p. : ill. (some col.) A print copy of this title is available through the UO Libraries under the call number: KNIGHT QP360.5 .B79 2008 / The ability to rapidly change from one course of action to another, i.e. "flexible behavior", is a hallmark of human cognition. Laboratory observations of switch costs, an increase in reaction time and errors when alternating between tasks compared to repeating a task, have been argued to be a measure of endogenous control during flexible behavior. However, alternative models suggest no such reconfiguration processes are necessary to account for performance in these task-switching situations. The first part of this dissertation uses neuroimaging to address whether reconfiguration processes do in fact occur in the explicit cuing variant of the task-switching paradigm. Using a 4:2 mapping between cues and tasks, we found neuroanatomical evidence for a dissociation between cue-switch (left prefrontal and lateral parietal) and task-switch (medial precuneus and cerebellar) related areas, consistent with the claim of endogenous control during task selection. The second portion explores whether automatic, long-term memory (LTM) processes can explain the "switch cost asymmetry", the fact that switch costs are larger when switching into a dominant task rather than into a competing non-dominant task. We modified an alternating runs task-switching paradigm to include either long or short response-to-stimulus intervals (RSIs) after each pair of trials (i.e., AA-AA-BB-BB), thereby inducing selection costs not only at the point of a task-switch (i.e., AA-BB), but also between same-task pairs (i.e., AA-AA). Using spatially compatible versus incompatible response rules and Stroop word versus color naming, we found asymmetric effects not only at task-change transitions, but also at task-repeat transitions when the RSI was long (presumably inducing frequent losses of task set). In two additional experiments, an asymmetry for long RSIs was obtained even when competing tasks were separated into alternating single task blocks, but not when the tasks were compared in a between-subject design. This pattern supports the idea that the asymmetry arises from interference effects occurring in LTM traces. The combined results of this dissertation characterize task-switching processes not as an "either-or" phenomenon in regards to the question of control, but rather as the interplay between top-down, executive functions and bottom-up, long-term memory priming mechanisms. / Adviser: Ulrich Mayr

No description available.

Deception has long been of interest to humans, but only recently has the neuroscience of deception started. Similarly, lie-detection, as an applied aspect of the study of deception, has long been studied but only with the advent of imaging techniques and the development of the neuroscience of deception has it become possible to develop techniques based on scanningour brains. Currently, both areas suffer from methodological and philosophical problems. As an applied science fMRI lie-detection has greater issues to deal with, specifically legal and ethical issues. Despite interesting results, implicating frontal regions as the neural correlates of deception, the neuroscience of deception need better designs and more study to be able to draw any general inferences. By its nature fMRI lie-detection suffers greatly from this, and additional problems concerning privacy and legality make it seem too early to implement it incourt or anywhere, as stated by many scientists. On the other hand the technology already exists and is likely to be used.

No description available.

Complicated grief, or persistent complex bereavement disorder, is a condition that affects approximately 10% of bereaved individuals and is marked by intense longing and yearning for the deceased. Little is known about the neurocognitive mechanisms contributing to this syndrome, but previous research suggests that reward pathways in the brain may play a role. The present study was designed with this theory in mind, aiming to understand reward processing in those experiencing complicated and non-complicated grief as well as to differentiate the "wanting" and "liking" phases of reward processing in bereavement. Twenty-five older adults were categorized based on grief severity into one of three groups: complicated grief (CG), non-complicated grief (NCG) and non-bereaved married controls (NB). Neural activation was examined using fMRI while participants viewed a countdown on the screen (anticipation) followed by a photo of their (living or deceased) spouse. There was no significantly differential activation between the three groups for the spouse v. stranger photo contrast, nor for anticipation period v. spouse photo. However, these two contrasts were also run separately in the three groups. Each group produced significant activation, in similar and distinct regions, primarily associated with emotion and visual processing. In addition, post-hoc analyses were conducted using self-reported yearning scores as a regressor across all bereaved participants, which revealed that greater symptoms of yearning predicted greater activation in the subgenual anterior cingulate cortex (sgACC). This region of the brain has been previously linked to depression and suggests that symptoms of yearning may present an opportune place to intervene to improve outcomes in CG.

Prisoners have high rates of physical and mental morbidity and of re-offending. There have been concerns that autism spectrum disorders (ASDs) may be overrepresented and under-diagnosed in this population. The aims of this study were to examine the effectiveness of an instrument which was developed to screen for ASDs in prisons and to establish whether male Scottish prisoners differ from community controls with respect to facial emotion recognition, as measured by behavioural testing, and differ on a neural basis while performing complex social judgements, as measured using functional magnetic resonance imaging (fMRI). A total of 2458 prisoners (approximately 40% of the convicted prison population) were examined using the screening tool, of whom a further 127 were interviewed in depth and were assessed for facial emotion recognition ability. FMRI was used to examine haemodynamic changes in a small sample of liberated prisoners (9) during a social judgement (approachability) versus control (gender judgments) task. The screening tool had poor sensitivity (28.6%) and specificity (75.6%) and was not effective or useful in screening for ASDs in this population. Significant deficits in negative facial emotion recognition were found in the prisoner group in comparison with age- and sex-matched community controls. Region of interest analysis of fMRI data in the bilateral amygdala revealed significantly greater activation in the left amygdala in ex-prisoners versus controls during the social judgement task. The identification of these abnormalities in facial emotion recognition and social judgement are in keeping with current literature on antisocial populations. They may offer the opportunity for development of interventions aimed at reducing re-offending in the future.

Individuals with developmental language impairment can show deficits into adulthood. This suggests that neural networks related to their language do not normalize with time. We examined the ability of 16 adults with and without impaired language to learn individual words in an unfamiliar language. Adults with impaired language were able to segment individual words from running speech, but needed more time to do so than their normal-language peers. ICA analysis of fMRI data indicated that adults with language impairment activate a neural network that is comparable to that of adults with normal language. However, a regional analysis indicated relative hyperactivation of a collection of regions associated with language processing. These results are discussed with reference to the Statistical Learning Framework and the sub-skills thought to relate to word segmentation. (C) 2017 The University of Arizona. Published by Elsevier Inc.

The neural basis of statistical learning as it occurs over time was explored with stimuli drawn from a natural language (Russian nouns). The input reflected the "rules" for marking categories of gendered nouns, without making participants explicitly aware of the nature of what they were to learn. Participants were scanned while listening to a series of gender-marked nouns during four sequential scans, and were tested for their learning immediately after each scan. Although participants were not told the nature of the learning task, they exhibited learning after their initial exposure to the stimuli. Independent component analysis of the brain data revealed five task- related sub- networks. Unlike prior statistical learning studies of word segmentation, this morphological learning task robustly activated the inferior frontal gyrus during the learning period. This region was represented in multiple independent components, suggesting it functions as a network hub for this type of learning. Moreover, the results suggest that subnetworks activated by statistical learning are driven by the nature of the input, rather than reflecting a general statistical learning system.

Four functional magnetic resonance imaging (fMRI) studies of pitch processing in auditory cortex were designed to reduce the impact of a number of methodological issues that have hitherto limited previous research findings. Due to adaptation effects, it is necessary to repeatedly present short stimulus bursts rather than long-duration stimuli. Thus, conventionally, in neuroimaging studies of pitch perception, a number of short bursts of the pitch stimulus, separated by silent intervals, are compared to a Gaussian noise presented in the same way. The results of the first experiment indicate that replacing the silent intervals with an energetically matched noise context increases the pitch-specific response by removing the 'energy-onset response' that saturates the overall response if silent intervals are used. In the second experiment, a particular pitch-evoking stimulus, iterated ripple noise (IRN), which is commonly used in neuroimaging studies of pitch perception, was examined. Hall and Plack (Cerebral Cortex 2009;19:576-585) showed that IRN contains slowly varying spectro-temporal features unrelated to pitch, and suggested that these features could account for at least some of the cortical activation produced by IRN. The results support this hypothesis, but also suggest that there is an additional pitch-dependent effect in the same region of auditory cortex.The third experiment assessed the effect of using a different control stimulus to the usual Gaussian noise. The new matched controls were a pulse train with randomly jittered inter-pulse intervals and a random-phase unresolved harmonic complex tone. These low-pitch-salience controls were compared to a regular interval pulse train, which is identical to a cosine-phase unresolved harmonic complex tone. The third experiment did not provide evidence for sensitivity to pitch-salience in pitch-responsive regions of auditory cortex. The fourth and final experiment was a factorial design seeking to answer two main questions: 1) Is the pitch-sensitive region of auditory cortex responsive to the salience of other sound features (e.g. modulation)? 2) Are the responses to pitch and to modulation within this region co-located? Two different pitch-evoking stimuli with different levels of pitch salience were used, presented in a noise context. Results indicate that the pitch-sensitive region contains representations for both pitch and modulation. Furthermore, there was no evidence for an interaction between pitch and modulation, suggesting that the two responses are independent. Overall, the results suggest that careful stimulus design, and appropriate experimental control, is necessary to obtain reliable information on the cortical response to pitch. In addition, the results have shed further light on the likely neural substrates of pitch processing in the cortex.