Browsing by Author "Harrison, Patti Kelly"

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    Acquired German Accent: A Functional Neural Systems Approach to Foreign Accent Syndrome
    Harrison, Patti Kelly; Klineburger, Philip C.; Campbell, Ransom W.; Harrison, David W. (2016-01-27)
    First described by French neurologist Pierre Marie in 1907, foreign accent syndrome (FAS) is a rare speech disorder in which individuals take on, what is perceived by observers, to be a distinct accent differing in many respects from the individual’s native accent. FAS has been of great interest in the neuropsychological literature because its unique features have challenged our understanding of the neural systems underlying the production of speech, shedding light on neural structures that had previously not been regarded as integral to speech production. In the approximately 60 reported cases of FAS, nearly all have involved a stroke or traumatic brain injury resulting in relatively small lesions (in comparison with one resulting in expressive aphasia) of the language dominant hemisphere in the prerolandic motor cortex, insular cortex, the frontal motor association cortex, and/or the striatum of the language dominant hemisphere (Blumstein & Kurowski, 2006). Several FAS cases with neuroimaging data have also shown lesions of the frontoparietal regions, right hemisphere, basal ganglia, and the right cerebellum (Marien, Verhoeven, Engelborghs, Rooker, Pickut, & De Deyn, 2006).
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    Capacity theory: A neuropsychological perspective on shared neural systems regulating hostile violence prone behavior and the metabolic syndrome
    Harrison, Patti Kelly; Walters, Robert P.; DeVore, Benjamin B.; Harrison, David W. (2016-01-13)
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    The dynamic opponent relativity model: an integration and extension of capacity theory and existing theoretical perspectives on the neuropsychology of arousal and emotion
    Comer, Clinton S.; Harrison, Patti Kelly; Harrison, David W. (Springer, 2015-07-14)
    Arousal theory as discussed within the present paper refers to those mechanisms and neural systems involved in central nervous system activation and more specifically the systems involved in cortical activation. Historical progress in the evolution of arousal theory has led to a better understanding of the functional neural systems involved in arousal or activation processes and ultimately contributed much to our current theories of emotion. Despite evidence for the dynamic interplay between the left and right cerebral hemispheres, the concepts of cerebral balance and dynamic activation have been emphasized in the neuropsychological literature. A conceptual model is proposed herein that incorporates the unique contributions from multiple neuropsychological theories of arousal and emotion. It is argued that the cerebral hemispheres may play oppositional roles in emotion partially due to the differences in their functional specializations and in their persistence upon activation. In the presence of a threat or provocation, the right hemisphere may activate survival relevant responses partially derived from hemispheric specializations in arousal and emotional processing, including the mobilization of sympathetic drive to promote heightened blood pressure, heart rate, glucose mobilization and respiratory support necessary for the challenge. Oppositional processes and mechanisms are discussed, which may be relevant to the regulatory control over the survival response; however, the capacity of these systems is necessarily limited. A limited capacity mechanism is proposed, which is familiar within other physiological systems, including that providing for the prevention of muscular damage under exceptional demand. This capacity theory is proposed, wherein a link may be expected between exceptional stress within a neural system and damage to the neural system. These mechanisms are proposed to be relevant to emotion and emotional disorders. Discussion is provided on the possible role of currently applied therapeutic interventions for emotional disorders.
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    The effect of anger expression style on cardiovascular responses to lateralized cognitive stressors
    Cox, David E.; DeVore, Benjamin B.; Harrison, Patti Kelly; Harrison, David W. (2017-12)
    To determine the effects of self-reported anger expression style on cerebrally lateralized physiological responses to neuropsychological stressors, changes in systolic blood pressure and heart rate were examined in response to a verbal fluency task and a figural fluency task among individuals reporting either "anger in" or "anger out" expression styles. Significant group by trial interaction effects was found for systolic blood pressure following administration of verbal fluency [F(1,54) = 5.86, p < 0.05] and nonverbal fluency stressors [F(1,54) = 13.68, p < .001]. Similar interactions were seen for systolic heart rate following administration of verbal fluency [F(1,54) = 5.86, p < .005] and nonverbal fluency stressors [F(1,54) = 13.68, p < .001]. The corresponding results are discussed in terms of functional cerebral systems and potential implications for physiological models of anger. Given the association between anger and negative physical health outcomes, there is a clear need to better understand the physiological components of anger. The results of this experiment indicate that a repressive "anger in" expression style is associated with deregulation of the right frontal region. This same region has been shown to be intimately involved in cardiovascular recovery, glucose metabolism, and blood pressure regulation.
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    The effect of rotation on legibility of dot-matrix characters
    Kurokawa, Ko (Virginia Tech, 1988-09-05)
    When dot-matrix characters are rotated, as might be the case in a moving map display, their dot-matrix patterns are distorted and their legibility is thus affected. In this experiment, 16 subjects performed a random search task, in which they were asked to look for a target in a random character pattern. The independent variables were the direction (clockwise or counterclockwise) and the angle of stimulus image rotation, and the target character's distance from the center of screen, which was also the center of rotation; the dependent variables were response time and response correctness. Significant effects were found in the angle of rotation, the target character's distance from the center, and the target character. The results indicate that (1) no angle-dependent mechanism is involved in performing this task and the angle of rotation influences recognition mainly through the distortion of dot-matrix patterns, (2) the target character's (radial) distance from the center of screen is the determining factor for search time, while the x and y coordinates of the target contributed to dot-matrix pattern distortion, and (3) the target characters interacted differently with the angle and distance factors to determine the extent of distortion and their legibility. Means to quantify the extent of distortion were discussed and the direction for future research is offered.
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    The effects of image quality on reading performance and perceived image quality from CRT and hard-copy displays
    Jorna, Gerard C. (Virginia Tech, 1989-08-05)
    The effects of physical image quality on reading and on perceived image quality from CRT and hard copy were studied in this experiment. The results showed that as the image quality of a display increased, indicated by an increase in the value of the MTFA, the reading speed increased and subjective image quality V; ratings increased. This change in reading speed and perceived image quality occurred in the hard copy as well as in the soft copy condition. Image quality, therefore, is concluded to be the major determinant of subjects' performance with respect to displayed information. This implies that if the image quality the displayed text ls the same on the display techniques used, subjects will read from CRT displays as fast as from hard copy displays.
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    Frontal lobe regulation of blood glucose levels: support for the limited capacity model in hostile violence-prone men
    Walters, Robert P.; Harrison, Patti Kelly; Campbell, Ransom W.; Harrison, David W. (2016-12)
    Hostile men have reliably displayed an exaggerated sympathetic stress response across multiple experimental settings, with cardiovascular reactivity for blood pressure and heart rate concurrent with lateralized right frontal lobe stress (Trajanoski et al., in Diabetes Care 19(12):1412-1415, 1996; see Heilman et al., in J Neurol Neurosurg Psychiatry 38(1):69-72, 1975). The current experiment examined frontal lobe regulatory control of glucose in high and low hostile men with concurrent left frontal lobe (Control Oral Word Association Test [verbal]) or right frontal lobe (Ruff Figural Fluency Test [nonverbal]) stress. A significant interaction was found for Group × Condition, F (1,22) = 4.16, p ≤ .05 with glucose levels (mg/dl) of high hostile men significantly elevated as a function of the right frontal stressor (M = 101.37, SD = 13.75) when compared to the verbal stressor (M = 95.79, SD = 11.20). Glucose levels in the low hostile group remained stable for both types of stress. High hostile men made significantly more errors on the right frontal but not the left frontal stressor (M = 17.18, SD = 19.88) when compared to the low hostile men (M = 5.81, SD = 4.33). These findings support our existing frontal capacity model of hostility (Iribarren et al., in J Am Med Assoc 17(19):2546-2551, 2000; McCrimmon et al., in Physiol Behav 67(1):35-39, 1999; Brunner et al., in Diabetes Care 21(4):585-590, 1998), extending the role of the right frontal lobe to regulatory control over glucose mobilization.
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    Frontal lobe regulatory control mechanisms: Evidence for diminished frontal eye field capacity in hostile violence-prone men
    Harrison, Patti Kelly; Campbell, Ransom W.; Smith, Andrew J.; Mitchell, Gina A.; Walters, Robert P.; Harrison, David W. (2016-02-03)
    Background: The experiment was designed to test the relationship between self-reported hostility and the capacity of frontal eye field regulatory control over visual smooth pursuit eye movements. Previous research has demonstrated a relationship between hostility, violence-prone aggression, and poorly regulated sympathetic control including traditional measures of cardiovascular risk. Capacity Theory (see Harrison, 2015) specifically predicts diminished reflex regulation, dystonia, or spasticity with conditions which exceed the capacity of the frontal systems involved in the response. For visual smooth pursuit eye movements, the frontal eye fields regulate/inhibit ipsilateral visuomotor reflexes under directional control of the superior colliculi and pontine region. Moreover, directional eye movements reflecting intentional direction of visual smooth pursuit derive from premotor regions at each dorsolateral frontal eye field and with directional intent toward the contralateral hemispace (e.g., right frontal eye field directs intentional eye movements toward the left hemispace and inhibits saccadic movements toward the right hemispace). Material/Methods: We tested a total number of 48 college-age men evenly divided between two groups, twenty-four low-hostiles and twenty-four high-hostiles. All subjects were acquired from the undergraduate Psychology pool and the project was approved by the Human Subjects Committee and the Institutional Review Board. In order to continue in the experiment, subjects had to have scored within either the low (0-19) or high (29-50) range of self-reported hostility onthe Cook-Medley Hostility Scale (CMHS). Due to their relatively heightened cerebral lateralization, only men were used to ensure as much homogeneity as possible within the experiment, so as to draw conclusions based solely on independent variable differences. Hostile men were compared with low hostile men using the electrooculogram (EOG). Smooth pursuit errors were identified in the EOG record as phasic errors in the analogue record. Results: Hostile men produced significantly more smooth pursuit irregularities in comparison with low hostiles, consistent with the predictions of Capacity Theory, supporting the contention of diminished frontal eye field integrity in hostile, violence-prone men. Conclusions: These findings sit collectively among a systematic line of research with accumulating evidence implicating capacity limitations for frontal lobe regulatory control in hostile, violence-prone individuals. The broader research implication is suggestive for remediation and preventative techniques for the amelioration of confrontative and/or coercive stress using these brain systems. Moreover, the theory specifically is predictive of heightened sensitivity for the sensory and emotional analyzers residing at the other end of the longitudinal tracts and within posterior brain regions. Emotional sensitivity reflecting coercive threat analysis, feelings of external control by others, and sensitivity to the emotional array presented by others’ facial expressions, tone of voice, and by innuendo may ultimately be a social disability. This effect may be propagated further in any social interaction where others may evaluate the hostile, violence-prone individual as insensitive and callous, perhaps.
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    Hallucinations and hemispatial neglect following right middle cerebral artery cerebrovascular accident: Left gaze bias with left sensory hemineglect syndrome
    Harrison, David H.; DeVore, Benjamin B.; Campbell, Ransom W.; Harrison, Patti Kelly (2017-12-12)
    Lesions within the right middle cerebral artery distribution commonly result in one or another variant of left hemineglect syndrome with sensory or attention deficits derived from damage within the posterior branches serving occipital, temporal, and parietal brain regions. Motor or intentional deficits within left hemispace have been commonly derived from damage within the anterior branches of the right middle cerebral artery.
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    A Social-Cognitive Assessment of Organizational Citizenship Behavior
    Fife, Cynthia Michelle (Virginia Tech, 2008-12-15)
    Organizational citizenship behavior (OCB) is essential to the smooth functioning of organizations. A vast amount of research examining OCB has established the benefits of such behavior to businesses. In addition, individual- and organizational-level antecedents of citizenship behavior have been widely studied and well established. However, a sound assessment of OCB, which acknowledges the true social cognitive nature of the phenomenon, is yet to be developed. The purpose of this study is two-fold: First, this study seeks to develop a reliable, accurate measure of OCB. Second, this study utilizes the newly developed measure to determine how personal characteristics and situational influences interact to produce helping behavior. More specifically, this study explores how equity sensitivity, locus of control, self-esteem, and affectivity determine whether an employee engages in helping behavior. Further, the current study examines whether situation cue strength moderates the relationship between the aforementioned personality characteristics and an employee's decision to engage in helping behavior.
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