Browsing by Subject "Frontal lobes"
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Item A MULTI-GROUP CONFIRMATORY FACTOR ANALYSIS OF THE REACTIVE- PROACTIVE AGGRESSION QUESTIONNAIRE IN A SAMPLE OF YOUNG ADULTS(2016-11-17) Cooke, Eric Meyers; Armstrong, Todd; Boisvert, Danielle; Zhang, YanAggression has long-term negative effects on humanity as a whole. Because of this, aggression has become an important topic of study across many disciplines. Originally conceptualized as being either non-impulsive or impulsive, aggression has become dichotomized as being reactive or proactive. Each form of aggression has been linked to a variety of genetic, psychological, physiological, and neurobiological correlates. Because research continues to grow in these fields surrounding proactive and reactive aggression, it is important to make sure that measurement tools are assessing aggression appropriately across a variety of groups. One such tool that has emerged recently is the Reactive-Proactive Aggression Questionnaire (RPQ; Raine et al., 2006). Though a number of studies exist testing the validity of the RPQ in adolescent and child populations. No such studies exist examining the factor structure and measurement invariance of proactive and reactive aggression in young adult male and females from different ethnicities. The current study assesses factor structure and measurement invariance in multiple groups of young North American adults. Results show that a two- factor, proactive-reactive, structure fits the current data overall. However, measurement invariance is not achieved across the majority of these groups. Meaning that interpretation of reactive and proactive scores is not the same across gender and ethnicity. Limitations and future directions are discussed.Item Differences in formal reasoning in terms of frontal lobe functioning(Texas Tech University, 1997-12) Taylor, Curtis ScottModem research in Neo-Piagetian theory has provided new interpretations of classical Piagetian concepts and developmental changes. Specifically, full cognitive development in adulthood does not appear to be as universal as may have earlier been believed. Some mature adults do not appear to develop the full range of cognitive complexity seen with formal and post-formal operational thought. The purpose of this dissertation is to explore differences between adults who do and do not show formal operational thought (as measured by the Logical Reasoning Test developed by Bumey in 1974). It was originally hypothesized that these groups would show significant differences in terms of frontal lobe performance on neuropsychological assessment tasks, as well as significant differences on a working-memory span task. Specifically, it was predicted that the formal operational adults would show superior performance on the neuropsychological battery, as well as larger working memory spans. Data collection and analysis has confirmed some, but not all of the author's hypotheses. Analysis using a series of multiple regression models has yielded valuable information regarding the Logical Reasoning Test, and has suggested future research possibilities.Item Left frontal neuropsychological functioning in paranoid and nonparanoid schizophrenics(Texas Tech University, 1983-12) Langell, Mary ElizabethNot availableItem Measurement of right frontal lobe functioning and attention-deficit/hyperactivity disorder(Texas Tech University, 2001-05) Hart, Christine CarolynAttention-deficit hyperactivity disorder (ADHD) is one of the most frequently diagnosed behavior problems among children referred for assessment and treatment. In recent years, neuropsychologists have considered ADHD as involving impaired executive functions (i.e., frontal lobe deficits) that may contribute to the central inattention and hyperactive-impulsive symptoms. Further, neurophysiological and neuroimaging findings have supported the involvement of prefrontal circuits in ADHD, particularly in the right hemisphere. Integration of the theoretical and neurophysiological literature on ADHD led to the current investigation of the disorder with measures purportedly sensitive to right frontal functioning. The present study investigated whether measurement of one area of executive dysfunction that has been theoretically linked in part to right frontal functioning would be of greater utility in identifying ADHD than previous, less specific cognitive measures. The participants included 40 boys aged 8-11 years of age who fulfilled current diagnostic criteria for ADHD. Forty sex-matched controls were also recruited. Each participant was individually assessed via a neuropsychological screening battery, which included intellectual functioning, achievement screening, bilateral and left frontal tests, sustained attention test, and tests specific to right frontal functions. It was found via a multivariate analysis of covariance that the combined measures (associated with bilateral frontal functioning and a measure of sustained attention) significantly differed between those with ADHD and without the disorder. Follow-up analyses revealed that, in particular, three components of the neuropsychological screening battery. Star Cancellation's missed stars, the Design Fluency Test's (DFT) complexity ratio, and the Wisconsin Card Sorting Test's (WCST) preservative responses aided in the discrimination of ADHD boys versus similarly aged controls. Further, it was found that when controlling for the effects of sustained attention, the multivariate effect of the measures in differentiating the groups' performances was no longer present. Exploratory analyses in regard to ADHD comorbid groups were also made. Limitations to the assessment of ADHD, particularly in regard to comorbidity, are also discussed. Overall, it appears that some frontal lobe- based measures, i.e., tests that are less structured, may be of clinical use in discriminating ADHD. Nevertheless, continued research in the area is needed.Item Role of the nucleus basalis in conditioned responses of cortical neurons in the rat(Texas Tech University, 1985-12) Rigdon, Greg CNeurons in the rat frontal cortex demonstrate altered firing rates in response to conditioned stimuli. Experiments were designed to test the hypothesis that the basal forebrain cholinergic systera is involved in the generation of conditioned neuronal responses in the rat frontal cortex. Most of the cholinergic innervation to the frontal cortex is supplied by projections frora the nucleus basalis raagnocellularis (nBM), A two-second tone cue imraediately followed by rewarding medial forebrain bundle stimulation was used to elicit the conditioned neuronal responses in the following experiraents. Experiment One was performed to determine the effects of inhibiting the firing of neurons in the nBM region on the conditioned responses. This was presuraably accomplished by microinjecting procaine, a local anesthetic, or GABA, an inhibitory neurotransraitter, into the nBM region. Procaine antagonized the conditioned responses of 86% of the cortical single units tested and GABA antagonized the responses of 81% of the units. Experiment Two was designed to investigate the effects of blocking cholinergic receptors on the conditioned responses of frontal cortex neurons. Microinjection of atropine, a cholinergic antagonist, into the frontal cortex suppressed the conditioned responses of 21 of 24 cortical single units. The nBM region was lesioned with kainic acid, a neurotoxin, in Experiment Three. The lesion resulted in a significant decrease in choline acetyltransferase activity in the frontal cortex ipsilateral to the nBM lesion. Only 25% of the neurons recorded in the frontal cortex on the side of the nBM lesion exhibited conditioned responses. This was significantly lower than the percentage of neurons that exhibited conditioned responses (70%) in the cortex of untreated animals. The firing rates of units in the nBM region were monitored during the cue-event paradigm in Experiment Four. Of the 38 unit recordings from the nBM region, 28 (74%) exhibited conditioned responses. The results from the four experiments together provide strong evidence for a role of the basal forebrain cholinergic system in the generation of conditioned single unit responses in the frontal cortex.Item The role of the frontal lobes in the inhibitory mechanisms of suppression(Texas Tech University, 1997-12) Nicodemus, Paul D.The primary hypothesis examined in the present experiment was that the executive functions of the frontal lobe play a dominant role in negative priming. Sbrty-one young adults performed various inhibitory reading tasks in which the participants identified redtarget letters while inhibiting green distractor letters. Participants also performed various inhibitory tasks that are commonly used in estimating performance levels of executive functions. The results of the inhibitory reading tasks showed that these participants demonstrated an interference effect and a facilitation effect; however, an overall negative priming effect was not found. Although a negative priming effect was not achieved, 39% of the participants displayed negative priming effects, 34% demonstrated positive priming effects, and the remaining partidpants (26%)showed no priming effects. A mixed factorial analysis showed that the negative primers completed both the reading tasks and the inhibitory tasks that involved executive functions in less time than either the positive primers or the no primers. A multiple regression analysis was computed in which the negative priming effect served as the dependent variable and the various inhibitory measurements for executive functions served as the independent variables. The results of this analysis indicated that the executive functions of the frontal lobe do not serve as good predictors for the negative priming effect. Therefore, no support was found for the hypothesis that the executive fimctions play a significant role in the inhibitory process of negative priming. These findings indicate that the type of priming demonstrated by the participant is the result of individual differences in their processing speed.